Zygotic and somatic embryo morphogenesis in Pinus pinaster: comparative histological and histochemical study.

PubMed

Tereso, Susana; Zoglauer, Kurt; Milhinhos, Ana; Miguel, Célia; Oliveira, M Margarida

2007-05-01

We compared morphogenesis and accumulation of storage proteins and starch in Pinus pinaster Ait. zygotic embryos with those in somatic embryos grown with different carbohydrate sources. The maturation medium for somatic embryos included 80 microM abscisic acid (ABA), 9 g l(-1) gellam gum and either glucose, sucrose or maltose at 44, 88, 175 or 263 mM in the presence or absence of 6% (w/v) polyethylene glycol (PEG) 4000 MW. Maturation medium containing 44 or 88 mM of a carbohydrate source produced only one or no cotyledonary somatic embryos per 0.6 g fresh mass of culture. The addition of PEG to the basal maturation medium resulted in a low yield of cotyledonary somatic embryos that generally showed incomplete development and anatomical abnormalities such as large intercellular spaces and large vacuoles. High concentrations of maltose also induced large intercellular spaces in the somatic embryonic cells, and 263 mM sucrose produced fewer and less developed cotyledonary somatic embryos compared with 175 mM sucrose, indicating that the effect of carbohydrate source is partially osmotic. Zygotic embryos had a lower dry mass than somatic embryos at the same stage of development. Starch granules followed a similar accumulation pattern in zygotic and somatic embryos. A low starch content was found in cotyledonary zygotic embryos and in somatic embryos developed in the presence of 175 mM maltose or 263 mM glucose. In zygotic embryos and in PEG-treated somatic embryos, protein bodies appeared later and were smaller and fewer than in well-developed somatic embryos grown without PEG. We propose that storage protein concentration might be a marker of embryo quality.

Goose embryonic development from oviposition through 16 hours of incubation.

PubMed

Lukaszewicz, E; Lason, M; Rosenberger, J; Kowalczyk, A; Bakst, M

2017-06-01

Normal tables provide an objective step-wise description of the morphological development of an embryo. Such tables have been described for the chicken, turkey, quail, and duck embryos, but there is no such staging table for goose embryos. As the goose has one of the longest incubation periods of all the poultry species and embryo mortality during incubation is relatively high, a normal table of goose embryo development would be useful in assessing the morpho-genetic status of the goose embryo before and during incubation. In this study, embryos were isolated from commercial White Koluda goose eggs stored no longer than four days in a cool room (18°C) prior to incubation and after 4, 8, 12, and 16 h of incubation. Embryo staging was based on the normal tables described for the chicken by Eyal-Giladi and Kochav (EGK) and Hamburger and Hamilton (HH). Goose embryos from unincubated eggs were at Stage X and XI EGK and after 16 h of incubation the majority of embryos were between Stages 2 and 4 HH. Our results suggest that while the stage of development of the embryo in the unincubated goose egg is similar to that reported for the chicken, although the diameter of goose embryo is slighter larger. Following incubation, a goose embryo advances more slowly than a chicken embryo up to 16 h of incubation. © 2016 Poultry Science Association Inc.

In vitro development of OPU-derived bovine embryos cultured either individually or in groups with the silk protein sericin and the viability of frozen-thawed embryos after transfer.

PubMed

Isobe, Tomohiro; Ikebata, Yoshihisa; Do, Lanh Thi Kim; Tanihara, Fuminori; Taniguchi, Masayasu; Otoi, Takeshige

2015-07-01

The optimization of single-embryo culture conditions is very important, particularly in the in vitro production of bovine embryos using the ovum pick-up (OPU) procedure. The purpose of this study was to examine the development of embryos derived from oocytes obtained by OPU that were cultured either individually or in groups in medium supplemented with or without sericin and to investigate the viability of the frozen-thawed embryos after a direct transfer. When two-cell-stage embryos were cultured either individually or in groups for 7 days in CR1aa medium supplemented with or without 0.5% sericin, the rates of development to blastocysts and freezable blastocysts were significantly lower for the embryos cultured individually without sericin than for the embryos cultured in groups with or without sericin. Moreover, the rate of development to freezable blastocysts of the embryos cultured individually with sericin was significantly higher than that of the embryos cultured without sericin. When the frozen-thawed embryos were transferred directly to recipients, the rates of pregnancy, abortion, stillbirth and normal calving in the recipients were similar among the groups, irrespective of the culture conditions and sericin supplementation. Our findings indicate that supplementation with sericin during embryo culture improves the quality of the embryos cultured individually but not the viability of the frozen-thawed embryos after transfer to recipients. © 2014 Japanese Society of Animal Science.

Preimplantation embryo development in vitro: cooperative interactions among embryos and role of growth factors.

PubMed Central

Paria, B C; Dey, S K

1990-01-01

We have established a model that shows cooperative interaction among preimplantation embryos and the role of growth factors on their development and growth. Two-cell mouse embryos cultured singly in 25-microliters microdrops had inferior development to blastocysts and lower cell numbers per blastocyst compared with those cultured in groups of 5 or 10. The inferior development of singly cultured embryos was markedly improved by addition of epidermal growth factor (EGF) or transforming growth factor alpha or beta 1 (TGF-alpha or TGF-beta 1) to the culture medium. The stage of embryonic development, primarily affected by these treatments, was between eight-cell/morula and blastocyst. Furthermore, blastocysts developed from eight-cell embryos cultured in groups or singly in the presence of EGF showed a higher incidence of zona hatching compared with those cultured singly in the absence of EGF. Detection of EGF receptors on the embryonic cell surface at eight-cell/morula and blastocyst stages suggests beneficial effects of EGF or TGF-alpha on preimplantation embryo development and blastocyst functions. Insulin-like growth factor I (IGF-I) had no influence on embryo development. To further document the cooperative interactions among embryos, the volume of the culture medium was doubled to 50 microliters. This increase in culture volume was even more detrimental to the development of singly cultured embryos. However, this detrimental effect was significantly reversed by EGF and reversed even more markedly by a combination of EGF and TGF-beta 1 but not by TGF-beta 1 alone. Although TGF-beta 1 plus IGF-I caused a modest improvement of embryo development, the response was not as great as shown by EGF alone. Furthermore, IGF-I had no additive effect on EGF-induced embryonic development. The study presents clear evidence that specific growth factors of embryonic and/or reproductive tract origin participate in preimplantation embryo development and blastocyst functions in an autocrine/paracrine manner. Images PMID:2352946

Photoautotrophic Culture of Coffea arabusta Somatic Embryos: Photosynthetic Ability and Growth of Different Stage Embryos

PubMed Central

AFREEN, F.; ZOBAYED, S. M. A.; KOZAI, T.

2002-01-01

Coffea arabusta somatic embryos were cultured and development of stomata, rate of CO2 fixation or production, chlorophyll content and chlorophyll fluorescence were studied in embryos at different stages of development. Cotyledonary and germinated embryos have photosynthetic capacity, although pretreatment at a high photosynthetic photon flux (PPF) (100 µmol m–2 s–1) for 14 d increased photosynthetic ability. Except in a very small number of cases, stomata did not develop fully in precotyledonary stage embryos and were absent in torpedo stage embryos. Low chlorophyll content (90–130 µg g–1 fresh mass) was noted in torpedo and precotyledonary stage embryos compared with cotyledonary and germinated embryos (300–500 µg g–1 fresh mass). Due to the absence of stomata and low chlorophyll content in the torpedo and precotyledonary stage embryos, the photosynthetic rate was low and, in some cases, CO2 production was observed. These data suggest that the cotyledonary stage is the earliest stage that can be cultured photoautotrophically to ensure plantlet development. When grown photoautotrophically (in a sugar‐free medium with CO2 enrichment in the culture headspace and high photosynthetic photon flux), torpedo and precotyledonary stage embryos lost 20–25 % of their initial dry mass after 60 d of culture. However, in cotyledonary and germinated embryos, the dry mass of each embryo increased by 10 and 50 %, respectively. By using a porous supporting material, growth (especially root growth) was increased in cotyledonary stage embryos. In addition, photoautotrophic conditions, high PPF (100–150 µmol m–2 s–1) and increased CO2 concentration (1100 µmol mol–1) were found to be necessary for the development of plantlets from cotyledonary stage embryos. PMID:12125763

Abscisic acid and osmoticum prevent germination of developing alfalfa embryos, but only osmoticum maintains the synthesis of developmental proteins.

PubMed

Xu, N; Coulter, K M; Derek Bewley, J

1990-10-01

Developing seeds of alfalfa (Medicago sativa L.) acquire the ability to germinate during the latter stages of development, the maturation drying phase. Isolated embryos placed on Murashige and Skoog medium germinate well during early and late development, but poorly during mid-development; however, when placed on water they germinate well only during the latter stage of development. Germination of isolated embryos is very slow and poor when they are incubated in the presence of surrounding seed structures (the endosperm or seed coat) taken from the mid-development stages. This inhibitory effect is also achieved by incubating embryos in 10(-5) M abscisic acid (ABA). Endogenous ABA attains a high level during mid-development, especially in the endosperm. Seeds developing in pods treated with fluridone (1-methyl-3-phenyl-5[3-(trifluoromethyl)-phenyl]-4(1H)-pyridinone) contain low levels of ABA during mid-development, and the endosperm and seed coat only weakly inhibit the germination of isolated embryos. However, intact seeds from fluridone-treated pods do not germinate viviparously, which is indicative that ABA alone is not responsible for maintaining seeds in a developing state. Application of osmoticum (e.g. 0.35 M sucrose) to isolated developing embryos prevents their germination. Also, in the developing seed in situ the osmotic potential is high. Thus internal levels of osmoticum may play a role in preventing germination of the embryo and maintaining development. Abscisic acid and osmoticum impart distinctly different metabolic responses on developing embryos, as demonstrated by their protein-synthetic capacity. Only in the presence of osmoticum do embryos synthesize proteins which are distinctly recognizable as those synthesized by developing embryos in situ, i.e. when inside the pod. Abscisic acid induces the synthesis of a few unique proteins, but these arise even in mature embryos treated with ABA. Thus while both osmoticum and ABA prevent precocious germination, their effects on the synthetic capacity of the developing embryo are quite distinct. Since seeds with low endogenous ABA do not germinate, osmotic regulation may be the more important of these two factors in controlling seed development.

Direct embryo tagging and identification system by attachment of biofunctionalized polysilicon barcodes to the zona pellucida of mouse embryos.

PubMed

Novo, Sergi; Penon, Oriol; Barrios, Leonardo; Nogués, Carme; Santaló, Josep; Durán, Sara; Gómez-Matínez, Rodrigo; Samitier, Josep; Plaza, José Antonio; Pérez-García, Luisa; Ibáñez, Elena

2013-06-01

Is the attachment of biofunctionalized polysilicon barcodes to the outer surface of the zona pellucida an effective approach for the direct tagging and identification of cultured embryos? The results achieved provide a proof of concept for a direct embryo tagging system using biofunctionalized polysilicon barcodes, which could help to minimize the risk of mismatching errors (mix-ups) in human assisted reproduction technologies. Even though the occurrence of mix-ups is rare, several cases have been reported in fertility clinics around the world. Measures to prevent the risk of mix-ups in human assisted reproduction technologies are therefore required. Mouse embryos were tagged with 10 barcodes and the effectiveness of the tagging system was tested during fresh in vitro culture (n=140) and after embryo cryopreservation (n = 84). Finally, the full-term development of tagged embryos was evaluated (n =105). Mouse pronuclear embryos were individually rolled over wheat germ agglutinin-biofunctionalized polysilicon barcodes to distribute them uniformly around the ZONA PELLUCIDA surface. Embryo viability and retention of barcodes were determined during 96 h of culture. The identification of tagged embryos was performed every 24 h in an inverted microscope and without embryo manipulation to simulate an automatic reading procedure. Full-term development of the tagged embryos was assessed after their transfer to pseudo-pregnant females. To test the validity of the embryo tagging system after a cryopreservation process, tagged embryos were frozen at the 2-cell stage using a slow freezing protocol, and followed in culture for 72 h after thawing. Neither the in vitro or in vivo development of tagged embryos was adversely affected. The tagging system also proved effective during an embryo cryopreservation process. Global identification rates higher than 96 and 92% in fresh and frozen-thawed tagged embryos, respectively, were obtained when simulating an automatic barcode reading system, although these rates could be increased to 100% by simply rotating the embryos during the reading process. The direct embryo tagging developed here has exclusively been tested in mouse embryos. Its effectiveness in other species, such as the human, is currently being tested. The direct embryo tagging system developed here, once tested in human embryos, could provide fertility clinics with a novel tool to reduce the risk of mix-ups in human assisted reproduction technologies.

Trichostatin A (TSA) improves the development of rabbit-rabbit intraspecies cloned embryos, but not rabbit-human interspecies cloned embryos.

PubMed

Shi, Li-Hong; Miao, Yi-Liang; Ouyang, Ying-Chun; Huang, Jun-Cheng; Lei, Zi-Li; Yang, Ji-Wen; Han, Zhi-Ming; Song, Xiang-Fen; Sun, Qing-Yuan; Chen, Da-Yuan

2008-03-01

The interspecies somatic cell nuclear transfer (iSCNT) technique for therapeutic cloning gives great promise for treatment of many human diseases. However, the incomplete nuclear reprogramming and the low blastocyst rate of iSCNT are still big problems. Herein, we observed the effect of TSA on the development of rabbit-rabbit intraspecies and rabbit-human interspecies cloned embryos. After treatment with TSA for 6 hr during activation, we found that the blastocyst rate of rabbit-rabbit cloned embryos was more than two times higher than that of untreated embryos; however, the blastocyst rate of TSA-treated rabbit-human interspecies cloned embryos decreased. We also found evident time-dependent histone deacetylation-reacetylation changes in rabbit-rabbit cloned embryos, but not in rabbit-human cloned embryos from fusion to 6 hr after activation. Our results suggest that TSA-treatment does not improve blastocyst development of rabbit-human iSCNT embryos and that abnormal histone deacetylation-reacetylation changes in iSCNT embryos may account for their poor blastocyst development. (c) 2008 Wiley-Liss, Inc.

Human endometrial cell coculture reduces the endocrine disruptor toxicity on mouse embryo development

PubMed Central

2012-01-01

Backgrounds Previous studies suggested that endocrine disruptors (ED) are toxic on preimplantation embryos and inhibit development of embryos in vitro culture. However, information about the toxicity of endocrine disruptors on preimplantation development of embryo in human reproductive environment is lacking. Methods Bisphenol A (BPA) and Aroclor 1254 (polychlorinated biphenyls) were used as endocrine disruptors in this study. Mouse 2-cell embryos were cultured in medium alone or vehicle or co-cultured with human endometrial epithelial layers in increasing ED concentrations. Results At 72 hours the percentage of normal blastocyst were decreased by ED in a dose-dependent manner while the co-culture system significantly enhanced the rate and reduced the toxicity of endocrine disruptors on the embryonic development in vitro. Conclusions In conclusion, although EDs have the toxic effect on embryo development, the co-culture with human endometrial cell reduced the preimplantation embryo from it thereby making human reproductive environment protective to preimplantation embryo from the toxicity of endocrine disruptors. PMID:22546201

Combined Transcriptome and Proteome Analysis Identifies Pathways and Markers Associated with the Establishment of Rapeseed Microspore-Derived Embryo Development1[W

PubMed Central

Joosen, Ronny; Cordewener, Jan; Supena, Ence Darmo Jaya; Vorst, Oscar; Lammers, Michiel; Maliepaard, Chris; Zeilmaker, Tieme; Miki, Brian; America, Twan; Custers, Jan; Boutilier, Kim

2007-01-01

Microspore-derived embryo (MDE) cultures are used as a model system to study plant cell totipotency and as an in vitro system to study embryo development. We characterized and compared the transcriptome and proteome of rapeseed (Brassica napus) MDEs from the few-celled stage to the globular/heart stage using two MDE culture systems: conventional cultures in which MDEs initially develop as unorganized clusters that usually lack a suspensor, and a novel suspensor-bearing embryo culture system in which the embryo proper originates from the distal cell of a suspensor-like structure and undergoes the same ordered cell divisions as the zygotic embryo. Improved histodifferentiation of suspensor-bearing MDEs suggests a new role for the suspensor in driving embryo cell identity and patterning. An MDE culture cDNA array and two-dimensional gel electrophoresis and protein sequencing were used to compile global and specific expression profiles for the two types of MDE cultures. Analysis of the identities of 220 candidate embryo markers, as well as the identities of 32 sequenced embryo up-regulated protein spots, indicate general roles for protein synthesis, glycolysis, and ascorbate metabolism in the establishment of MDE development. A collection of 135 robust markers for the transition to MDE development was identified, a number of which may be coregulated at the gene and protein expression level. Comparison of the expression profiles of preglobular-stage conventional MDEs and suspensor-bearing MDEs identified genes whose differential expression may reflect improved histodifferentiation of suspensor-bearing embryos. This collection of early embryo-expressed genes and proteins serves as a starting point for future marker development and gene function studies aimed at understanding the molecular regulation of cell totipotency and early embryo development in plants. PMID:17384159

Maize embryogenesis.

PubMed

Fontanet, Pilar; Vicient, Carlos M

2008-01-01

Plant embryo development is a complex process that includes several coordinated events. Maize mature embryos consist of a well-differentiated embryonic axis surrounded by a single massive cotyledon called scutellum. Mature embryo axis also includes lateral roots and several developed leaves. In contrast to Arabidopsis, in which the orientation of cell divisions are perfectly established, only the first planes of cell division are predictable in maize embryos. These distinctive characteristics joined to the availability of a large collection of embryo mutants, well-developed molecular biology and tissue culture tools, an established genetics and its economical importance make maize a good model plant for grass embryogenesis. Here, we describe basic concepts and techniques necessary for studying maize embryo development: how to grow maize in greenhouses and basic techniques for in vitro embryo culture, somatic embryogenesis and in situ hybridization.

Effect of sericin on preimplantation development of bovine embryos cultured individually.

PubMed

Isobe, T; Ikebata, Y; Onitsuka, T; Wittayarat, M; Sato, Y; Taniguchi, M; Otoi, T

2012-09-01

The silk protein sericin has been identified as a potent antioxidant in mammalian cells. This study was conducted to examine the effects of sericin on preimplantation development and quality of bovine embryos cultured individually. When two-cell-stage embryos were cultured individually for 7 days in CR1aa medium supplemented with 0, 0.1, 0.5, or 1% sericin, rates of total blastocyst formation and development to expanded blastocysts from embryos cultured with 0.5% sericin were higher (P < 0.05) than those from embryos cultured with 0 or 1% sericin. When embryos were cultured individually for 7 days in the CR1aa medium supplemented with 0 or 0.5% sericin under two oxidative stress conditions (50 or 100 μm H(2)O(2)), the addition of sericin significantly improved the blastocyst formation rate of embryos exposed to 100 μm H(2)O(2). However, the protective effect of sericin was not observed in development of embryos exposed to 50 μm H(2)O(2). When embryos were exposed to 100 μm H(2)O(2) during culture, the DNA fragmentation index of total blastocysts from embryos cultured with 0.5% sericin was lower than blastocysts derived from embryos cultured without sericin (4.4 vs. 6.8%; P < 0.01). In conclusion, the addition of 0.5% sericin to in vitro culture medium improved preimplantation development and quality of bovine embryos cultured individually by preventing oxidative stress. Copyright © 2012 Elsevier Inc. All rights reserved.

PreImplantation Factor (PIF) correlates with early mammalian embryo development-bovine and murine models

PubMed Central

2011-01-01

Background PreImplantation Factor (PIF), a novel peptide secreted by viable embryos is essential for pregnancy: PIF modulates local immunity, promotes decidual pro-adhesion molecules and enhances trophoblast invasion. To determine the role of PIF in post-fertilization embryo development, we measured the peptide's concentration in the culture medium and tested endogenous PIF's potential trophic effects and direct interaction with the embryo. Methods Determine PIF levels in culture medium of multiple mouse and single bovine embryos cultured up to the blastocyst stage using PIF-ELISA. Examine the inhibitory effects of anti-PIF-monoclonal antibody (mAb) added to medium on cultured mouse embryos development. Test FITC-PIF uptake by cultured bovine blastocysts using fluorescent microscopy. Results PIF levels in mouse embryo culture medium significantly increased from the morula to the blastocyst stage (ANOVA, P = 0.01). In contrast, atretic embryos medium was similar to the medium only control. Detectable - though low - PIF levels were secreted already by 2-cell stage mouse embryos. In single bovine IVF-derived embryos, PIF levels in medium at day 3 of culture were higher than non-cleaving embryos (control) (P = 0.01) and at day 7 were higher than day 3 (P = 0.03). In non-cleaving embryos culture medium was similar to medium alone (control). Anti-PIF-mAb added to mouse embryo cultures lowered blastocyst formation rate 3-fold in a dose-dependent manner (2-way contingency table, multiple groups, X2; P = 0.01) as compared with non-specific mouse mAb, and medium alone, control. FITC-PIF was taken-up by cultured bovine blastocysts, but not by scrambled FITC-PIF (control). Conclusions PIF is an early embryo viability marker that has a direct supportive role on embryo development in culture. PIF-ELISA use to assess IVF embryo quality prior to transfer is warranted. Overall, our data supports PIF's endogenous self sustaining role in embryo development and the utility of PIF- ELISA to detect viable embryos in a non-invasive manner. PMID:21569635

Analysis of global gene expression profiles to identify differentially expressed genes critical for embryo development in Brassica rapa.

PubMed

Zhang, Yu; Peng, Lifang; Wu, Ya; Shen, Yanyue; Wu, Xiaoming; Wang, Jianbo

2014-11-01

Embryo development represents a crucial developmental period in the life cycle of flowering plants. To gain insights into the genetic programs that control embryo development in Brassica rapa L., RNA sequencing technology was used to perform transcriptome profiling analysis of B. rapa developing embryos. The results generated 42,906,229 sequence reads aligned with 32,941 genes. In total, 27,760, 28,871, 28,384, and 25,653 genes were identified from embryos at globular, heart, early cotyledon, and mature developmental stages, respectively, and analysis between stages revealed a subset of stage-specific genes. We next investigated 9,884 differentially expressed genes with more than fivefold changes in expression and false discovery rate ≤ 0.001 from three adjacent-stage comparisons; 1,514, 3,831, and 6,633 genes were detected between globular and heart stage embryo libraries, heart stage and early cotyledon stage, and early cotyledon and mature stage, respectively. Large numbers of genes related to cellular process, metabolism process, response to stimulus, and biological process were expressed during the early and middle stages of embryo development. Fatty acid biosynthesis, biosynthesis of secondary metabolites, and photosynthesis-related genes were expressed predominantly in embryos at the middle stage. Genes for lipid metabolism and storage proteins were highly expressed in the middle and late stages of embryo development. We also identified 911 transcription factor genes that show differential expression across embryo developmental stages. These results increase our understanding of the complex molecular and cellular events during embryo development in B. rapa and provide a foundation for future studies on other oilseed crops.

[Traditional and modern approaches to culture of preimplantation mammalian embryos in vitro].

PubMed

Brusentsev, E Iu; Igonina, T N; Amstislavskiĭ, S Ia

2014-01-01

This review covers the basic principles and methods of in vitro culture of preimplantation mammalian embryos. The features of in vitro development of embryos of various species of animals with allowance for the composition of nutrient media are described, with special attention paid to those species that have traditionally been consideredas laboratory (i.e., mice, rats, and hamsters). The effects of suboptimal culturing conditions of preimplantation embryos on the formation of the phenotype of individuals developed from these embryos are discussed. New approaches to optimize the conditions of the development of preimplantation mammalian embryos in vitro are analyzed.

In vitro development rate of preimplantation rabbit embryos cultured with different levels of melatonin.

PubMed

Mehaisen, Gamal Mohamed Kamel; Saeed, Ayman Moustafa

2015-02-01

This study aimed to investigate the effect of melatonin supplementation at different levels in culture medium on embryo development in rabbits. Embryos of 2-4 cells, 8-16 cells and morula stages were recovered from nulliparous Red Baladi rabbit does by laparotomy technique 24, 48 and 72 h post-insemination, respectively. Normal embryos from each stage were cultured to hatched blastocyst stages in either control culture medium (TCM-199 + 20% fetal bovine serum) or control supplemented with melatonin at 10(-3) M, 10(-6) M or 10(-9) M. No effect of melatonin was found on development of embryos recovered at 24 h post-insemination. The high level of melatonin at 10(-3) M adversely affected the in vitro development rates of embryos recovered at 48 h post-insemination (52 versus 86, 87 and 80% blastocyst rate; 28 versus 66, 78 and 59% hatchability rate for 10(-3) M versus 10(-9) M, 10(-6) M and control, respectively, P< 0.05). At the morula stage, melatonin at 10-3 M significantly increased the in vitro development of embryos (92% for 10(-3) M versus 76% for control, P < 0.05), while the hatchability rate of these embryos was not improved by melatonin (16-30% versus 52% for melatonin groups versus control, P < 0.05). Results show that a moderate level of melatonin (10(-6) M) may improve the development and hatchability rates of preimplantation rabbit embryos. The addition of melatonin at a 10-3 M concentration enhances the development of rabbit morulae but may negatively affect the development of earlier embryos. More studies are needed to optimize the use of melatonin in in vitro embryo culture in rabbits.

Short communication: expression and alternative splicing of POU1F1 pathway genes in preimplantation bovine embryos.

PubMed

Laporta, J; Driver, A; Khatib, H

2011-08-01

Early embryo loss is a major contributing factor to cow infertility and that 70 to 80% of this loss occurs between d 8 and 16 postfertilization. However, little is known about the molecular mechanisms and the nature of genes involved in normal and abnormal embryonic development. Moreover, information is limited on the contributions of the genomes of dams and of embryos to the development and survival of preimplantation embryos. We hypothesized that proper gene expression level in the developing embryo is essential for embryo survival and pregnancy success. As such, the characterization of expression profiles in early embryos could lead to a better understanding of the mechanisms involved in normal and abnormal embryo development. To test this hypothesis, 2 d-8 embryo populations (degenerate embryos and blastocysts) that differed in morphology and developmental status were investigated. Expression levels of POU1F1 pathway genes were estimated in 4 sets of biological replicate pools of degenerate embryos and blastocysts. The OPN and STAT5A genes were found to be upregulated in degenerate embryos compared with blastocysts, whereas STAT5B showed similar expression levels in both embryo groups. Analysis of splice variants of OPN and STAT5A revealed expression patterns different from the total expression values of these genes. As such, measuring expression of individual transcripts should be considered in gene expression studies. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Timing of The First Zygotic Cleavage Affects Post-Vitrification Viability of Murine Embryos Produced In Vivo

PubMed Central

Jusof, Wan-Hafizah Wan; Khan, Nor-Ashikin Mohamed Noor; Rajikin, Mohd Hamim; Satar, Nuraliza Abdul; Mustafa, Mohd-Fazirul; Jusoh, Norhazlin; Dasiman, Razif

2015-01-01

Background Timing of the first zygotic cleavage is an accurate predictor of embryo quality. Embryos that cleaved early (EC) have been shown to exhibit higher develop- mental viability compared to those that cleaved at a later period (LC). However, the vi- ability of EC embryos in comparison to LC embryos after vitrification is unknown. The present study aims to investigate the post-vitrification developmental viability of murine EC versus LC embryos. Materials and Methods In this experimental study, female ICR mice (6-8 weeks old) were superovulated and cohabited with fertile males for 24 hours. Afterwards, their ovi- ducts were excised and embryos harvested. Embryos at the 2-cell stage were catego- rized as EC embryos, while zygotes with two pronuclei were categorized as LC embryos. Embryos were cultured in M16 medium supplemented with 3% bovine serum albumin (BSA) in a humidified 5% CO2atmosphere. Control embryos were cultured until the blastocyst stage without vitrification. Experimental embryos at the 2-cell stage were vitri- fied for one hour using 40% v/v ethylene glycol, 18% w/v Ficoll-70 and 0.5 M sucrose as the cryoprotectant. We recorded the numbers of surviving embryos from the control and experimental groups and their development until the blastocyst stage. Results were analyzed using the chi-square test. Results A significantly higher proportion of EC embryos (96.7%) from the control group developed to the blastocyst stage compared with LC embryos (57.5%, P<0.0001). Similarly, in the experimental group, a significantly higher percentage of vitrified EC embryos (69.4%) reached the blastocyst stage compared to vitrified LC embryos (27.1%, P<0.0001). Conclusion Vitrified EC embryos are more vitrification tolerant than LC embryos. Prese- lection of EC embryos may be used as a tool for selection of embryos that exhibit higher developmental competence after vitrification. PMID:26246881

Silver nanoparticles induce developmental stage-specific embryonic phenotypes in zebrafish

NASA Astrophysics Data System (ADS)

Lee, Kerry J.; Browning, Lauren M.; Nallathamby, Prakash D.; Osgood, Christopher J.; Xu, Xiao-Hong Nancy

2013-11-01

Much is anticipated from the development and deployment of nanomaterials in biological organisms, but concerns remain regarding their biocompatibility and target specificity. Here we report our study of the transport, biocompatibility and toxicity of purified and stable silver nanoparticles (Ag NPs, 13.1 +/- 2.5 nm in diameter) upon the specific developmental stages of zebrafish embryos using single NP plasmonic spectroscopy. We find that single Ag NPs passively diffuse into five different developmental stages of embryos (cleavage, early-gastrula, early-segmentation, late-segmentation, and hatching stages), showing stage-independent diffusion modes and diffusion coefficients. Notably, the Ag NPs induce distinctive stage and dose-dependent phenotypes and nanotoxicity, upon their acute exposure to the Ag NPs (0-0.7 nM) for only 2 h. The late-segmentation embryos are most sensitive to the NPs with the lowest critical concentration (CNP,c << 0.02 nM) and highest percentages of cardiac abnormalities, followed by early-segmentation embryos (CNP,c < 0.02 nM), suggesting that disruption of cell differentiation by the NPs causes the most toxic effects on embryonic development. The cleavage-stage embryos treated with the NPs develop into a wide variety of phenotypes (abnormal finfold, tail/spinal cord flexure, cardiac malformation/edema, yolk sac edema, and acephaly). These organ structures are not yet developed in cleavage-stage embryos, suggesting that the earliest determinative events to create these structures are ongoing, and disrupted by NPs, which leads to the downstream effects. In contrast, the hatching embryos are most resistant to the Ag NPs, and majority of embryos (94%) develop normally, and none of them develop abnormally. Interestingly, early-gastrula embryos are less sensitive to the NPs than cleavage and segmentation stage embryos, and do not develop abnormally. These important findings suggest that the Ag NPs are not simple poisons, and they can target specific pathways in development, and potentially enable target specific study and therapy for early embryonic development.Much is anticipated from the development and deployment of nanomaterials in biological organisms, but concerns remain regarding their biocompatibility and target specificity. Here we report our study of the transport, biocompatibility and toxicity of purified and stable silver nanoparticles (Ag NPs, 13.1 +/- 2.5 nm in diameter) upon the specific developmental stages of zebrafish embryos using single NP plasmonic spectroscopy. We find that single Ag NPs passively diffuse into five different developmental stages of embryos (cleavage, early-gastrula, early-segmentation, late-segmentation, and hatching stages), showing stage-independent diffusion modes and diffusion coefficients. Notably, the Ag NPs induce distinctive stage and dose-dependent phenotypes and nanotoxicity, upon their acute exposure to the Ag NPs (0-0.7 nM) for only 2 h. The late-segmentation embryos are most sensitive to the NPs with the lowest critical concentration (CNP,c << 0.02 nM) and highest percentages of cardiac abnormalities, followed by early-segmentation embryos (CNP,c < 0.02 nM), suggesting that disruption of cell differentiation by the NPs causes the most toxic effects on embryonic development. The cleavage-stage embryos treated with the NPs develop into a wide variety of phenotypes (abnormal finfold, tail/spinal cord flexure, cardiac malformation/edema, yolk sac edema, and acephaly). These organ structures are not yet developed in cleavage-stage embryos, suggesting that the earliest determinative events to create these structures are ongoing, and disrupted by NPs, which leads to the downstream effects. In contrast, the hatching embryos are most resistant to the Ag NPs, and majority of embryos (94%) develop normally, and none of them develop abnormally. Interestingly, early-gastrula embryos are less sensitive to the NPs than cleavage and segmentation stage embryos, and do not develop abnormally. These important findings suggest that the Ag NPs are not simple poisons, and they can target specific pathways in development, and potentially enable target specific study and therapy for early embryonic development. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03210h

Calcium-sensing receptor (CASR) is involved in porcine in vitro fertilisation and early embryo development.

PubMed

Liu, C; Liu, Y; Larsen, K; Hou, Y P; Callesen, H

2018-01-01

It has been demonstrated that extracellular calcium is necessary in fertilisation and embryo development but the mechanism is still not well understood. The present study mainly focussed on the extracellular calcium effector called the calcium-sensing receptor (CASR) and examined its expression in porcine gametes and embryos and its function during fertilisation and early embryo development. By using reverse transcription polymerase chain reaction, CASR was found to be expressed in porcine oocytes, spermatozoa and embryos at different developmental stages. Functionally, medium supplementation with a CASR agonist or an antagonist during in vitro fertilisation (IVF) and in vitro culture (IVC) was tested. During fertilisation, the presence of a CASR agonist increased sperm penetration rate and decreased polyspermy rate leading to an increased normal fertilisation rate. During embryo development, for the IVF embryos, agonist treatment during IVC significantly increased cleavage rate and blastocyst formation rate compared with the control group. Furthermore, parthenogenetically activated embryos showed similar results with lower cleavage and blastocyst formation rates in the antagonist group than in the other groups. It was concluded that CASR, as the effector of extracellular calcium, modulates porcine fertilisation and early embryo development.

Reproductive success in a natural population of male three-spined stickleback Gasterosteus aculeatus: effects of nuptial colour, parasites and body size.

PubMed

Sparkes, T C; Rush, V; Kopp, D A; Foster, S A

2013-05-01

The effects of nuptial colour, parasites and body size on reproductive success were examined in a natural population of three-spined stickleback Gasterosteus aculeatus. Reproductive males were collected, with the contents of their nests, during the embryo-guarding stage from Lynne Lake (Cook Inlet, Alaska, U.S.A.), and nuptial colour, infection status and body size were recorded. Regression analysis revealed that male body size was the only predictor, of those measured, of reproductive success in nature. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

[Embryos and embryo-like entities: problem of definition in the draft of the Swiss embryonic research law].

PubMed

Bürgin, M T; Bürkli, P

2002-11-01

At the end of May 2002, the draft of the Swiss "Federal Act on Research on Surplus Embryos and Embryonic Stem Cells" (EFG, Embryonic Research Act) reached the pre-legislative consultation stage. Under certain conditions, it would allow research on "surplus" embryos from in-vitro fertilization, and the derivation of embryonic stem cells from surplus embryos for research purposes. The EFG draft defines an embryo as "the developing organism from the point of nuclear fusion until the completion of organ development". New technological developments show that embryo-like entities can also be created without nuclear fusion having taken place. It remains unclear how to treat embryonic entities that don't fall under the draft's narrow definition of an embryo. Expanding this definition would be a welcome improvement.

[Effect of human oviductal embryotrophic factors on gene expression of mouse preimplantation embryos].

PubMed

Yao, Yuan-Qing; Lee, Kai-Fai; Xu, Jia-Seng; Ho, Pak-Chung; Yeung, Shu-Biu

2007-09-01

To investigate the effect of embryotrophic factors (ETF) from human oviductal cells on gene expression of mouse early developmental embryos and discuss the role of fallopian tube in early development of embryos. ETF was isolated from conditioned medium of human oviductal cell line by sequential liquid chromatographic systems. Mouse embryos were treated by ETF in vitro. Using differential display RT-PCR, the gene expression of embryos treated by ETF was compared with embryos without ETF treatment. The differentially expressed genes were separated, re-amplified, cloned and sequenced. Gene expression profiles of embryos with ETF treatment was different from embryos without this treatment. Eight differentially expressed genes were cloned and sequenced. These genes functioned in RNA degradation, synthesis, splicing, protein trafficking, cellular differentiation and embryo development. Embryotrophic factors from human oviductal cells affect gene expression of early developmental embryos. The human oviductal cells play wide roles in early developmental stages of embryos.

Polyamine levels during the development of zygotic and somatic embryos of Pinus radiata

Treesearch

Rakesh Minocha; Dale R. Smith; Cathie Reeves; Kevin D. Steele; Subhash C. Minocha

1999-01-01

Changes in the cellular content of three polyamines (putrescine, spermidine and spermine) were compared at different stages of development in zygotic and somatic embryos of Pinus radiata D. Don. During embryo development, both the zygotic and the somatic embryos showed a steady increase in spermidine content, with either a small decrease or no...

HSPC117 deficiency in cloned embryos causes placental abnormality and fetal death

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yingying; State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080; Graduate University of Chinese Academy of Sciences, Beijing 100049

2010-07-02

Somatic cell nuclear transfer (SCNT) has been successfully used in many species to produce live cloned offspring, albeit with low efficiency. The low frequency of successful development has usually been ascribed to incomplete or inappropriate reprogramming of the transferred nuclear genome. Elucidating the genetic differences between normal fertilized and cloned embryos is key to understand the low efficiency of SCNT. Here, we show that expression of HSPC117, which encodes a hypothetical protein of unknown function, was absent or very low in cloned mouse blastocysts. To investigate the role of HSPC117 in embryo development, we knocked-down this gene in normal fertilizedmore » embryos using RNA interference. We assessed the post-implantation survival of HSPC117 knock-down embryos at 3 stages: E9 (prior to placenta formation); E12 (after the placenta was fully functional) and E19 (post-natal). Our results show that, although siRNA-treated in vivo fertilized/produced (IVP) embryos could develop to the blastocyst stage and implanted without any difference from control embryos, the knock-down embryos showed substantial fetal death, accompanied by placental blood clotting, at E12. Furthermore, comparison of HSPC117 expression in placentas of nuclear transfer (NT), intracytoplasmic sperm injection (ICSI) and IVP embryos confirmed that HSPC117 deficiency correlates well with failures in embryo development: all NT embryos with a fetus, as well as IVP and ICSI embryos, had normal placental HSPC117 expression while those NT embryos showing reduced or no expression of HSPC117 failed to form a fetus. In conclusion, we show that HSPC117 is an important gene for post-implantation development of embryos, and that HSPC117 deficiency leads to fetal abnormalities after implantation, especially following placental formation. We suggest that defects in HSPC117 expression may be an important contributing factor to loss of cloned NT embryos in vivo.« less

Use of the Coelomic Grafting Technique for Prolonged ex utero Cultivation of Late Preprimitive Streak-Stage Rabbit Embryos.

PubMed

Püschel, Bernd; Männer, Jörg

2016-01-01

Due to its morphological similarity with the early human embryo, the pregastrulation-stage rabbit may represent an appropriate mammalian model for studying processes involved in early human development. The usability of mammalian embryos for experimental studies depends on the availability of whole embryo culture methods facilitating prolonged ex utero development. While currently used culture methods yield high success rates for embryos from primitive streak stages onward, the success rate of extended cultivation of preprimitive streak-stage mammalian embryos is low for all previously established methods and for all studied species. This limits the usability of preprimitive streak-stage rabbit embryos in experimental embryology. We have tested whether the extraembryonic coelom of 4-day-old chick embryos may be used for prolonged ex utero culture of preprimitive streak-stage rabbit embryos (stage 2, 6.2 days post coitum). We found that, within this environment, stage 2 rabbit blastocysts can be cultured at decreasing success rates (55% after 1 day, 35% after 2 days, 15% after 3 days) up to a maximum of 72 h. Grafted blastocysts can continue development from the onset of gastrulation to early organogenesis and thereby form all structures characterizing age-matched controls (e.g. neural tube, somites, beating heart). Compared to normal controls, successfully cultured embryos developed at a slower rate and finally showed some structural and gross morphological anomalies. The method presented here was originally developed for whole embryo culture of mouse embryos by Gluecksohn-Schoenheimer in 1941. It is a simple and inexpensive method that may represent a useful extension to presently available ex utero culture systems for rabbit embryos. © 2016 S. Karger AG, Basel.

Random Walk of Single Gold Nanoparticles in Zebrafish Embryos Leading to Stochastic Toxic Effects on Embryonic Developments

PubMed Central

Browning, Lauren M.; Lee, Kerry J.; Huang, Tao; Nallathamby, Prakash D.; Lowman, Jill E.; Xu, Xiao-Hong Nancy

2010-01-01

We have synthesized and characterized stable (non-aggregation, non-photobleaching and non-blinking), nearly monodisperse and highly-purified Au nanoparticles, and used them to probe transport of cleavage-stage zebrafish embryos and to study their effects on embryonic development in real time. We found that single Au nanoparticles (11.6 ± 0.9 nm in diameter) passively diffused into chorionic space of the embryos via their chorionic-pore-canals and continued their random-walk through chorionic space and into inner mass of embryos. Diffusion coefficients of single nanoparticles vary dramatically (2.8×10-11 to 1.3×10-8 cm2/s) as nanoparticles diffuse through various parts of embryos, suggesting highly diverse transport barriers and viscosity gradients of embryos. The amount of Au nanoparticles accumulated in embryos increase with its concentration. Interestingly, their effects on embryonic development are not proportionally related to the concentration. Majority of embryos (74% on average) incubated chronically with 0.025-1.2 nM Au nanoparticles for 120 h developed to normal zebrafish, with some (24%) being dead and few (2%) deformed. We developed a new approach to image and characterize individual Au nanoparticles embedded in tissues using histology sample preparation methods and LSRP spectra of single nanoparticles. We found that Au nanoparticles in various parts of normally developed and deformed zebrafish, suggesting that random-walk of nanoparticles in embryos during their development might have led to stochastic effects on embryonic development. These results show that Au nanoparticles are much more biocompatible (less toxic) to the embryos than Ag nanoparticles that we reported previously, suggesting that they are better suited as biocompatible probes for imaging embryos in vivo. The results provide powerful evidences that biocompatibility and toxicity of nanoparticles highly depend on their chemical properties, and the embryos can serve as effective in-vivo assays to screen their biocompatibility. PMID:20644873

In vitro development of donated frozen-thawed human embryos in a prototype static microfluidic device: a randomized controlled trial.

PubMed

Kieslinger, Dorit C; Hao, Zhenxia; Vergouw, Carlijn G; Kostelijk, Elisabeth H; Lambalk, Cornelis B; Le Gac, Séverine

2015-03-01

To compare the development of human embryos in microfluidic devices with culture in standard microdrop dishes, both under static conditions. Prospective randomized controlled trial. In vitro fertilization laboratory. One hundred eighteen donated frozen-thawed human day-4 embryos. Random allocation of embryos that fulfilled the inclusion criteria to single-embryo culture in a microfluidics device (n = 58) or standard microdrop dish (n = 60). Blastocyst formation rate and quality after 24, 28, 48, and 72 hours of culture. The percentage of frozen-thawed day-4 embryos that developed to the blastocyst stage did not differ significantly in the standard microdrop dishes and microfluidic devices after 28 hours of culture (53.3% vs. 58.6%) or at any of the other time points. The proportion of embryos that would have been suitable for embryo transfer was comparable after 28 hours of culture in the control dishes and microfluidic devices (90.0% vs. 93.1%). Furthermore, blastocyst quality was similar in the two study groups. This study shows that a microfluidic device can successfully support human blastocyst development in vitro under static culture conditions. Future studies need to clarify whether earlier stage embryos will benefit from the culture in microfluidic devices more than the tested day-4 embryos because many important steps in the development of human embryos already take place before day 4. Further improvements of the microfluidic device will include parallel culture of single embryos, application of medium refreshment, and built-in sensors. NTR3867. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Effect of Medium Salt Concentration on Differentiation and Maturation of Somatic Embryos of Cassava (Manihot esculenta Crantz)

PubMed Central

GROLL, J.; MYCOCK, D. J.; GRAY, V. M.

2002-01-01

Culture of cassava somatic embryos on media with an altered macro‐ and micro‐nutrient salt concentration affected embryo development and germination capability. In the tests, quarter‐, half‐, full‐ or double‐strength Murashige and Skoog (MS) media were compared. The maximum number of somatic embryos differentiated from a proliferative nodular embryogenic callus (NEC) on either half‐ or full‐strength MS medium, and the greatest numbers of cotyledonary stage embryos were formed on full‐strength MS medium. Developed somatic embryos were then desiccated above a saturated K2SO4 solution for 10 d. After transfer to germination medium, embryos that had developed on half‐ and full‐strength MS medium yielded 8·3 and 8·6 germinants g–1 NEC tissue, respectively. For this important but often disregarded culture factor, either half‐ or full‐strength MS medium is recommended for both the differentiation and development of cassava somatic embryos that are capable of germination. PMID:12099540

Embryo developmental events and the egg case of the Aleutian skate Bathyraja aleutica (Gilbert) and the Alaska skate Bathyraja parmifera (Bean).

PubMed

Hoff, G R

2009-02-01

Embryo development events were correlated with egg-case changes for the Aleutian skate Bathyraja aleutica and the Alaska skate Bathyraja parmifera. Yolk absorption underwent two phases: that of steady absorption during early development and that of rapid yolk absorption during the final development stages. Total length (L(T)) for 50% of the pre-hatching embryos egg-case jelly disappearance was 92.04 mm (range 81-102 mm) and 99.36 mm (range 81-100 mm) for B. aleutica and B. parmifera, respectively, allowing the inner chamber to open to seawater flow. The tail filament underwent three phases of growth: rapid elongation during early development (<100 mm embryo L(T)), stasis of tail filament length during the remainder of embryo development and rapid absorption soon after hatching. Complete tail filament development coincided with the disappearance of egg-case jelly. Clasper buds first developed at embryos >70 mm L(T) for both species and the sex ratio was 1:1 well before hatching. Egg cases that were devoid of an ova or developing embryo were c. 5.0 and 6.5% of the egg cases examined for B. aleutica and B. parmifera, respectively. Measurements showed that egg cases containing only egg jelly were smaller in both width and length than those possessing an ova. Embryo stages were punctuated with distinct events that correlated with egg case changes controlling the internal environment of the developing embryo.

Early morphological nuclear events and developmental capacity of embryos reconstructed with fetal fibroblasts at the M or G1 phase after intracytoplasmic nuclear injection in cattle.

PubMed

Ideta, Atsushi; Urakawa, Manami; Aoyagi, Yoshito; Saeki, Kazuhiro

2005-04-01

We examined morphological nuclear events during the first cell cycle of bovine embryos reconstructed with somatic cells at the M and G1 phases (M-embryos and G1-embryos, respectively) by intracytoplasmic nuclear injection, and the subsequent development of these embryos in vitro and in vivo. Bovine fetal fibroblasts (BFFs) at the M or G1 phase were directly injected into enucleated oocytes, and activated immediately. Only half (48%) of the M-embryos extruded polar body-like cells (PBCs) at 6 h post injection (hpi). At 15 to 19 hpi, 54% of the M-embryos formed a single pronucleus-like nucleus. Nuclear envelope-breakdown, premature chromosome condensation and single nuclear clusters were observed in most of the G1-embryos (88%) within 30 min following the nuclear injection. At 15 to 19 hpi, single pronucleus-like nuclei were formed in most G1-embryos (83%). The potential of G1-embryos to develop to blastocysts was significantly higher than that of M-embryos (31% vs 16%). Three of five recipients following transfer of blastocysts derived from the G1-embryos became pregnant on Day 30, and one recipient delivered a calf. Our results indicate that almost a half of the M-embryos failed to extrude PBCs and that the G1-embryos developed to blastocysts at a higher rate than the M-embryos.

Secondary SCNT doubles the pre-implantation development rate of reconstructed interspecies embryos by using cytoplasts of Sannen dairy goat ova.

PubMed

Zhang, Ai Min; Chen, Jian Quan; Sha, Hong Ying; Chen, Juan; Xu, Xu Jun; Wu, You Bin; Ge, Lai Xiang; Da, Hu Wei; Cheng, Guo Xiang

2007-10-01

The aim of this study was to investigate whether ova of Sannen goat could support the pre-implantation development of interspecies embryos constructed through somatic cell nucleus transfer (SCNT) embryos and whether secondary SCNT (SSCNT) could improve the pre-implantation development of those embryos. The primary SCNT (PSCNT) embryos were produced by using Sannen goat ovum cytoplasts as recipients and fibroblast cells, derived from human, rabbit and Boer goat skins, as nucleus donors. The blastomeres of 8 to 16 cells stage of PSCNT embryos were subsequently used as nucleus donor cells and Sannen goat ovum cytoplasts as recipients to evaluate the effect of SSCNT on the pre-implantation development rate of these reconstructed interspecies embryos. Our results indicate that the pre-implantation development rates of SSCNT embryos reconstructed using these three different blastomeres are almost twice of that of corresponding PSCNT embryos (human, 15.8% vs. 7.8%; rabbit, 27.9% vs. 12.5%; Boer goat 55.3% vs. 24.5%; P < 0.05 in all three cases). The time durations that embryos need for the serial events of remodeling and reprogramming to take place vary, depending on the animal species of nucleus donors. These data suggest that remodeling and reprogramming of donor nucleus may be enhanced by prolonged exposure of donor nucleus to maternal cytoplast. We conclude that Sannen goat cytoplast can support the pre-implantation development of embryos constructed with nuclei from various donors, including fibroblasts of human, rabbit and Boer goat; and the somatic nucleus derived from different species requires more time to achieve its reprogramming necessary for pre-implantation development.

Stimulus-triggered enhancement of chilling tolerance in zebrafish embryos

PubMed Central

Szabó, Katalin; Budai, Csilla; Losonczi, Eszter; Bernáth, Gergely; Csenki-Bakos, Zsolt; Urbányi, Béla; Pribenszky, Csaba; Horváth, Ákos; Cserepes, Judit

2017-01-01

Background Cryopreservation of zebrafish embryos is still an unsolved problem despite market demand and massive efforts to preserve genetic variation among numerous existing lines. Chilled storage of embryos might be a step towards developing successful cryopreservation, but no methods to date have worked. Methods In the present study, we applied a novel strategy to improve the chilling tolerance of zebrafish embryos by introducing a preconditioning hydrostatic pressure treatment to the embryos. In our experiments, 26-somites and Prim-5 stage zebrafish embryos were chilled at 0°C for 24 hours after preconditioning. Embryo survival rate, ability to reach maturation and fertilizing capacity were tested. Results Our results indicate that applied preconditioning technology made it possible for the chilled embryos to develop normally until maturity, and to produce healthy offspring as normal, thus passing on their genetic material successfully. Treated embryos had a significantly higher survival and better developmental rate, moreover the treated group had a higher ratio of normal morphology during continued development. While all controls from chilled embryos died by 30 day-post-fertilization, the treated group reached maturity (~90–120 days) and were able to reproduce, resulting in offspring in expected quantity and quality. Conclusions Based on our results, we conclude that the preconditioning technology represents a significant improvement in zebrafish embryo chilling tolerance, thus enabling a long-time survival. Furthermore, as embryonic development is arrested during chilled storage this technology also provides a solution to synchronize or delay the development. PMID:28166301

Oxygen regulates amino acid turnover and carbohydrate uptake during the preimplantation period of mouse embryo development.

PubMed

Wale, Petra L; Gardner, David K

2012-07-01

Oxygen is a powerful regulator of preimplantation embryo development, affecting gene expression, the proteome, and energy metabolism. Even a transient exposure to atmospheric oxygen can have a negative impact on embryo development, which is greatest prior to compaction, and subsequent postcompaction culture at low oxygen cannot alleviate this damage. In spite of this evidence, the majority of human in vitro fertilization is still performed at atmospheric oxygen. One of the physiological parameters shown to be affected by the relative oxygen concentration, carbohydrate metabolism, is linked to the ability of the mammalian embryo to develop in culture and remain viable after transfer. The aim of this study was, therefore, to determine the effect of oxygen concentration on the ability of mouse embryos to utilize both amino acids and carbohydrates both before and after compaction. Metabolomic and fluorometric analysis of embryo culture media revealed that when embryos were exposed to atmospheric oxygen during the cleavage stages, they exhibited significantly greater amino acid utilization and pyruvate uptake than when cultured under 5% oxygen. In contrast, postcompaction embryos cultured in atmospheric oxygen showed significantly lower mean amino acid utilization and glucose uptake. These metabolic changes correlated with developmental compromise because embryos grown in atmospheric oxygen at all stages showed significantly lower blastocyst formation and proliferation. These findings confirm the need to consider both embryo development and metabolism in establishing optimal human embryo growth conditions and prognostic markers of viability, and further highlight the impact of oxygen on such vital parameters.

Protein Phosphorylation during Coconut Zygotic Embryo Development1

PubMed Central

Islas-Flores, Ignacio; Oropeza, Carlos; Hernández-Sotomayor, S.M. Teresa

1998-01-01

Evidence was obtained on the occurrence of protein threonine, serine, and tyrosine (Tyr) kinases in developing coconut (Cocos nucifera L.) zygotic embryos, based on in vitro phosphorylation of proteins in the presence of [γ-32P]ATP, alkaline treatment, and thin-layer chromatography analysis, which showed the presence of [32P]phosphoserine, [32P]phosphothreonine, and [32P]phosphotyrosine in [32P]-labeled protein hydrolyzates. Tyr kinase activity was further confirmed in extracts of embryos at different stages of development using antiphosphotyrosine monoclonal antibodies and the synthetic peptide derived from the amino acid sequence surrounding the phosphorylation site in pp60src (RR-SRC), which is specific for Tyr kinases. Anti-phosphotyrosine western blotting revealed a changing profile of Tyr-phosphorylated proteins during embryo development. Tyr kinase activity, as assayed using RR-SRC, also changed during embryo development, showing two peaks of activity, one during early and another during late embryo development. In addition, the use of genistein, a Tyr kinase inhibitor, diminished the ability of extracts to phosphorylate RR-SRC. Results presented here show the occurrence of threonine, serine, and Tyr kinases in developing coconut zygotic embryos, and suggest that protein phosphorylation, and the possible inference of Tyr phosphorylation in particular, may play a role in the coordination of the development of embryos in this species. PMID:9733545

Selection of Norway spruce somatic embryos by computer vision

NASA Astrophysics Data System (ADS)

Hamalainen, Jari J.; Jokinen, Kari J.

1993-05-01

A computer vision system was developed for the classification of plant somatic embryos. The embryos are in a Petri dish that is transferred with constant speed and they are recognized as they pass a line scan camera. A classification algorithm needs to be installed for every plant species. This paper describes an algorithm for the recognition of Norway spruce (Picea abies) embryos. A short review of conifer micropropagation by somatic embryogenesis is also given. The recognition algorithm is based on features calculated from the boundary of the object. Only part of the boundary corresponding to the developing cotyledons (2 - 15) and the straight sides of the embryo are used for recognition. An index of the length of the cotyledons describes the developmental stage of the embryo. The testing set for classifier performance consisted of 118 embryos and 478 nonembryos. With the classification tolerances chosen 69% of the objects classified as embryos by a human classifier were selected and 31$% rejected. Less than 1% of the nonembryos were classified as embryos. The basic features developed can probably be easily adapted for the recognition of other conifer somatic embryos.

Effect of Culture Conditions on Viability of Mouse and Rat Embryos Developed in Vitro

PubMed Central

Popova, Elena; Bader, Michael; Krivokharchenko, Alexander

2011-01-01

Currently in vitro culture of mouse preimplantation embryos has become a very important technique to investigate different mechanisms of early embryogenesis. However, there is a big difference in the preimplantation development between mammalian species. Despite close relatedness to mice, in vitro cultivation of rat preimplantation embryos is still delicate and needs further investigation and optimizations. In this study we have compared the in vitro developmental potential of mouse and rat embryos cultured at different culture conditions in parallel experiments. Interestingly, mouse zygotes developed in vitro until blastocyst stage even in inadequate medium without any phosphates and with low osmolarity which was formulated especially for cultivation of rat embryos. Rat parthenotes and zygotes developed in M16 medium formulated for mouse embryos only till 2-cell stage and further development is blocked completely at this stage. Moreover, developmental ability of rat embryos in vitro was significantly lower in comparison with mouse even in special rat mR1ECM medium. Mouse and rat embryos at 2-cell stage obtained in vivo developed until blastocyst stages significantly more efficiently compared to zygotes. Culture of mouse zygotes in glass capillaries resulted in a significantly higher rate of morula and blastocyst development compared with dishes. The Well-of-the-Well system resulted in a significant improvement when compared with dishes for the culture of rat zygotes only until morula stage. Reduced oxygen tension increased the developmental rate of rat but not mouse zygotes until blastocyst stage. This study demonstrates that development of early preimplantation embryos is altered by different culture conditions and show strong differences even between two related species such as mice and rats. Therefore, for understanding the fundamental mechanisms of early mammalian development it is very important to use embryos of various species. PMID:24710194

Polyamines and their biosynthetic enzymes during somatic embryo development in red spruce (Picea rubens Sarg.)

Treesearch

Rakesh Minocha; Subhash C. Minocha; Stephanie Long

2004-01-01

The major objective of this study was to determine if the observed changes in polyamines and their biosynthetic enzymes during somatic embryo development were specifically related to either the stage of the embryo development or to the duration of time spent on the maturation medium. Somatic embryos of red spruce (Picea rubens) at different...

Development of whole and demi-embryos of mice in culture and in vivo after supercooled storage.

PubMed

Fuku, E; Fiser, P S; Marcus, G J; Sasada, H; Downey, B R

1993-12-01

Demi-embryos (produced by destroying 1 or 2 blastomeres of 2- or 4-cell embryos, respectively) and intact mouse embryos were cultured to the blastocyst stage, stored at -5 degrees C for 48 h, then cultured for 24 h and transferred into pseudopregnant recipients. Supercooled storage did not impair the developmental potential of whole or demi-embryos in vitro, nor was there a difference between whole and demi-embryos with respect to growth in vitro. Similarly, there was no effect of supercooling on development of intact or demi embryos after transfer into pseudopregnant recipient mice, but fewer recipients of demi-embryos remained pregnant (P < 0.05). This was considered to be partly due to the lesser ability of demi-embryos to maintain luteal function and establish pregnancy.

Growth and metabolism of murine and bovine embryos in bovine uterine flushing-supplemented culture media.

PubMed Central

Rondeau, M; Guay, P; Goff, A K; Cooke, G M

1996-01-01

The aim of this study was to compare the development and metabolic activity of cultured murine and bovine embryos in 2 standard media (HAM F-10 and RPMI) in the presence or absence of bovine uterine flushings. Murine morulae (n = 653) and day 7 bovine embryos (n = 273) were cultured for 18 h or 36 h in either HAM F-10 or RPMI in the presence or absence of bovine uterine flushings. After culture, the development, quality, and metabolic activity (glucose utilization or methionine uptake and incorporation) of embryos was assessed. It was found that HAM F-10 (without uterine flushings) was a more suitable medium than RPMI for optimal development and metabolism of murine and bovine embryos. Poor quality and development, as well as decreased metabolism, were evident after culture of murine embryos in RPMI; in contrast, this medium had no adverse effects on bovine embryos in culture. Supplementation of HAM F-10 with bovine uterine flushings improved the growth of murine embryos and the protein synthesis (as measured by an increased methionine incorporation) for both murine and bovine embryos. However, supplementation with bovine uterine flushings could not overcome deficiencies of an inappropriate medium (RPMI) for murine embryos. Supplementation of a well-defined culture medium with uterine flushings increased metabolism of embryos in culture, and thus might help to increase pregnancy rates after transfer of such embryos to recipient cows. PMID:8825988

Preimplantation diagnosis to create 'saviour siblings': a critical discussion of the current and future legal frameworks in South Africa.

PubMed

Strode, Ann; Soni, Sheetal

2011-12-14

Pre-implantation genetic diagnosis (PGD) is a technology used in conjunction with in vitro fertilisation to screen embryos for genetic conditions prior to transfer. It was initially developed to screen mutations for severe, irreversible, genetic conditions. Currently, PGD makes it possible to select against more than 100 different genetic conditions. It has been proposed as a method for creating a tissue-matched child who can in turn serve as a compatible stem cell donor to save a sick sibling in need of a stem cell transplant. The advantage of this method is that it provides genetic information before implantation of an embryo into the womb, making it possible to ensure that only tissue-matched embryos are transferred to the uterus. A couple can therefore avoid the difficult choice of either terminating the pregnancy at a later point if the fetus is not a match, or extending their family again in the hope that their next child will be tissue compatible. Many people have expressed disapproval of the use of PGD for this purpose, and it is associated with many conflicting interests including religion, ethics as well as legal regulation. In order to manage these issues some jurisdictions have created legal frameworks to regulate the use of this technology. Many of these are modelled on the UK's Human Fertilisation and Embryology Authority and its guardian legislation. This paper critiques the current and future South African legal framework to establish whether it is able to adequately regulate the use of PGD as well as guard against misuse of the technology. It concludes that changes are required to the future framework in order to ensure that it regulates the circumstances in which PGD may occur and that the Minister of Health should act expediently in finalising draft regulations which will regulate PGD in the future.

Improving Metabolic Health in Obese Male Mice via Diet and Exercise Restores Embryo Development and Fetal Growth

PubMed Central

McPherson, Nicole O.; Bakos, Hassan W.; Owens, Julie A.; Setchell, Brian P.; Lane, Michelle

2013-01-01

Paternal obesity is now clearly associated with or causal of impaired embryo and fetal development and reduced pregnancy rates in humans and rodents. This appears to be a result of reduced blastocyst potential. Whether these adverse embryo and fetal outcomes can be ameliorated by interventions to reduce paternal obesity has not been established. Here, male mice fed a high fat diet (HFD) to induce obesity were used, to determine if early embryo and fetal development is improved by interventions of diet (CD) and/or exercise to reduce adiposity and improve metabolism. Exercise and to a lesser extent CD in obese males improved embryo development rates, with increased cell to cell contacts in the compacting embryo measured by E-cadherin in exercise interventions and subsequently, increased blastocyst trophectoderm (TE), inner cell mass (ICM) and epiblast cell numbers. Implantation rates and fetal development from resulting blastocysts were also improved by exercise in obese males. Additionally, all interventions to obese males increased fetal weight, with CD alone and exercise alone, also increasing fetal crown-rump length. Measures of embryo and fetal development correlated with paternal measures of glycaemia, insulin action and serum lipids regardless of paternal adiposity or intervention, suggesting a link between paternal metabolic health and subsequent embryo and fetal development. This is the first study to show that improvements to metabolic health of obese males through diet and exercise can improve embryo and fetal development, suggesting such interventions are likely to improve offspring health. PMID:23977045

Embryo Aggregation in Pig Improves Cloning Efficiency and Embryo Quality.

PubMed

Buemo, Carla Paola; Gambini, Andrés; Moro, Lucia Natalia; Hiriart, María Inés; Fernández-Martín, Rafael; Collas, Philippe; Salamone, Daniel Felipe

2016-01-01

In this study, we analyzed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst diameter and cell number, DNA fragmentation levels and the expression of genes associated with pluripotency, apoptosis, trophoblast and DNA methylation in the porcine. Zona-free reconstructed cloned embryos were cultured in the well of the well system, placing one (1x non aggregated group) or three (3x group) embryos per microwell. Our results showed that aggregation of three embryos increased blastocyst formation rate and blastocyst diameter of cloned pig embryos. DNA fragmentation levels in 3x aggregated cloned blastocysts were significantly decreased compared to 1x blastocysts. Levels of Oct4, Klf4, Igf2, Bax and Dnmt 1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially non-detectable. Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.

Expression of genes involved in early cell fate decisions in human embryos and their regulation by growth factors.

PubMed

Kimber, S J; Sneddon, S F; Bloor, D J; El-Bareg, A M; Hawkhead, J A; Metcalfe, A D; Houghton, F D; Leese, H J; Rutherford, A; Lieberman, B A; Brison, D R

2008-05-01

Little is understood about the regulation of gene expression in human preimplantation embryos. We set out to examine the expression in human preimplantation embryos of a number of genes known to be critical for early development of the murine embryo. The expression profile of these genes was analysed throughout preimplantation development and in response to growth factor (GF) stimulation. Developmental expression of a number of genes was similar to that seen in murine embryos (OCT3B/4, CDX2, NANOG). However, GATA6 is expressed throughout preimplantation development in the human. Embryos were cultured in IGF-I, leukaemia inhibitory factor (LIF) or heparin-binding EGF-like growth factor (HBEGF), all of which are known to stimulate the development of human embryos. Our data show that culture in HBEGF and LIF appears to facilitate human embryo expression of a number of genes: ERBB4 (LIF) and LIFR and DSC2 (HBEGF) while in the presence of HBEGF no blastocysts expressed EOMES and when cultured with LIF only two out of nine blastocysts expressed TBN. These data improve our knowledge of the similarities between human and murine embryos and the influence of GFs on human embryo gene expression. Results from this study will improve the understanding of cell fate decisions in early human embryos, which has important implications for both IVF treatment and the derivation of human embryonic stem cells.

Rabbit somatic cell cloning: effects of donor cell type, histone acetylation status and chimeric embryo complementation.

PubMed

Yang, Feikun; Hao, Ru; Kessler, Barbara; Brem, Gottfried; Wolf, Eckhard; Zakhartchenko, Valeri

2007-01-01

The epigenetic status of a donor nucleus has an important effect on the developmental potential of embryos produced by somatic cell nuclear transfer (SCNT). In this study, we transferred cultured rabbit cumulus cells (RCC) and fetal fibroblasts (RFF) from genetically marked rabbits (Alicia/Basilea) into metaphase II oocytes and analyzed the levels of histone H3-lysine 9-lysine 14 acetylation (acH3K9/14) in donor cells and cloned embryos. We also assessed the correlation between the histone acetylation status of donor cells and cloned embryos and their developmental potential. To test whether alteration of the histone acetylation status affects development of cloned embryos, we treated donor cells with sodium butyrate (NaBu), a histone deacetylase inhibitor. Further, we tried to improve cloning efficiency by chimeric complementation of cloned embryos with blastomeres from in vivo fertilized or parthenogenetic embryos. The levels of acH3K9/14 were higher in RCCs than in RFFs (P<0.05). Although the type of donor cells did not affect development to blastocyst, after transfer into recipients, RCC cloned embryos induced a higher initial pregnancy rate as compared to RFF cloned embryos (40 vs 20%). However, almost all pregnancies with either type of cloned embryos were lost by the middle of gestation and only one fully developed, live RCC-derived rabbit was obtained. Treatment of RFFs with NaBu significantly increased the level of acH3K9/14 and the proportion of nuclear transfer embryos developing to blastocyst (49 vs 33% with non-treated RFF, P<0.05). The distribution of acH3K9/14 in either group of cloned embryos did not resemble that in in vivo fertilized embryos suggesting that reprogramming of this epigenetic mark is aberrant in cloned rabbit embryos and cannot be corrected by treatment of donor cells with NaBu. Aggregation of embryos cloned from NaBu-treated RFFs with blastomeres from in vivo derived embryos improved development to blastocyst, but no cloned offspring were obtained. Two live cloned rabbits were produced from this donor cell type only after aggregation of cloned embryos with a parthenogenetic blastomere. Our study demonstrates that the levels of histone acetylation in donor cells and cloned embryos correlate with their developmental potential and may be a useful epigenetic mark to predict efficiency of SCNT in rabbits.

Unaltered timing of embryo development in women with polycystic ovarian syndrome (PCOS): a time-lapse study.

PubMed

Sundvall, Linda; Kirkegaard, Kirstine; Ingerslev, Hans Jakob; Knudsen, Ulla Breth

2015-07-01

Polycystic ovarian syndrome (PCOS) is a common cause of female infertility. Factors other than anovulation, such as low embryo quality have been suggested to contribute to the infertility in these women. This 2-year retrospective study used timelapse technology to investigate the PCOS-influence on timing of development in the pre-implantation embryo (primary endpoint). The secondary outcome measure was live birth rates after elective single-embryo transfer. In total, 313 embryos from 43 PCOS women, and 1075 embryos from 174 non-PCOS women undergoing assisted reproduction were included. All embryos were monitored until day 6. Differences in embryo kinetics were tested in a covariance regression model to account for potential confounding variables: female age, BMI, fertilization method and male infertility. Time to initiate compaction and reach the morula stage as well as the duration of the 4th cleavage division was significantly shorter in PCOS embryos compared with non-PCOS embryos. No other kinetic differences were found at any time-points annotated. The proportion of multi-nucleated cells at the 2-cell stage was significantly higher in PCOS embryos compared with non-PCOS embryos. The live birth rates were comparable between the two groups. The findings suggest that the causative factor for subfertility in PCOS is not related to timing of development in the pre-implantation embryo.

PXD101 significantly improves nuclear reprogramming and the in vitro developmental competence of porcine SCNT embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Jun-Xue; Kang, Jin-Dan; Li, Suo

2015-01-02

Highlights: • First explored that the effects of PXD101 on the development of SCNT embryos in vitro. • 0.5 μM PXD101 treated for 24 h improved the development of porcine SCNT embryos. • Level of AcH3K9 was significantly higher than control group at early stages. - Abstract: In this study, we investigated the effects of the histone deacetylase inhibitor PXD101 (belinostat) on the preimplantation development of porcine somatic cell nuclear transfer (SCNT) embryos and their expression of the epigenetic markers histone H3 acetylated at lysine 9 (AcH3K9). We compared the in vitro developmental competence of SCNT embryos treated with variousmore » concentrations of PXD101 for 24 h. Treatment with 0.5 μM PXD101 significantly increased the proportion of SCNT embryos that reached the blastocyst stage, in comparison to the control group (23.3% vs. 11.5%, P < 0.05). We tested the in vitro developmental competence of SCNT embryos treated with 0.5 μM PXD101 for various amounts of times following activation. Treatment for 24 h significantly improved the development of porcine SCNT embryos, with a significantly higher proportion of embryos reaching the blastocyst stage in comparison to the control group (25.7% vs. 10.6%, P < 0.05). PXD101-treated SCNT embryos were transferred into two surrogate sows, one of whom became pregnant and four fetuses developed. PXD101 treatment significantly increased the fluorescence intensity of immunostaining for AcH3K9 in embryos at the pseudo-pronuclear and 2-cell stages. At these stages, the fluorescence intensities of immunostaining for AcH3K9 were significantly higher in PXD101-treated embryos than in control untreated embryos. In conclusion, this study demonstrates that PXD101 can significantly improve the in vitro and in vivo developmental competence of porcine SCNT embryos and can enhance their nuclear reprogramming.« less

Effect of Short-Term Hypergravity Treatment on Mouse 2-Cell Embryo Development

NASA Astrophysics Data System (ADS)

Ning, Li-Na; Lei, Xiao-Hua; Cao, Yu-Jing; Zhang, Yun-Fang; Cao, Zhong-Hong; Chen, Qi; Duan, En-Kui

2015-11-01

Though there are numerous biological experiments, which have been performed in a space environment, to study the physiological effect of space travel on living organisms, while the potential effect of weightlessness or short-term hypergravity on the reproductive system in most species, particularly in mammalian is still controversial and unclear. In our previous study, we investigated the effect of space microgravity on the development of mouse 4-cell embryos by using Chinese SJ-8. .Unexpectedly, we did not get any developed embryo during the space-flight. Considering that the process of space experiment is quite different from most experiments done on earth in several aspects such as, the vibration and short-term hypergravity during the rock launching and landing. Thus we want to know whether the short-term hypergravity produced by the launch process affect the early embryo development in mice, and howthe early embryos respond to the hypergravity. In present study, we are mimicking the short-term hypergravity during launch by using a centrifuge to investigate its influence on the development of early embryo (2-cell) in mice. We also examined the actin filament distribution in 2-cell embryos by immunostaining to test their potential capacity of development under short-term hypergravity exposure. Our results showed that most 2-cell embryos in the hypergravity exposure groups developed into blastocysts with normal morphology after 72h cultured in vitro, and there is no obvious difference in the development rate of blastocyst formation compared to the control. Moreover, there were no statistically significant differences in birth rates after oviduct transfer of 2-cell mouse embryos exposed on short-term hypergravity compared with 1 g condition. In addition, the well-organized actin distribution appeared in 2-cell embryos after exposed on hypergravity and also in the subsequent developmental blastocysts. Taken together, our data shows that short-term exposure in hypergravity conditions does not affect the normal development and actin filament structures of mouse embryos.

Research Methods to Develop Measures of Effectiveness of the United States Coast Guard’s Vessel Inspection and Boarding Program. Executive Summary - Volume I

DTIC Science & Technology

1995-05-01

Service, Springfield, Virginia 22161 Prepared for: LJCý U.S. Coast Guard Research and Development Center 1082 Shennecossett Road < Groton, Connecticut...States Coast Guard Research & Development Center 1082 Shennecossett Road Groton, CT 06340-6096 ii Technical Report Documentation Paae 1. Report No. 2...U.S. Coast Guard 14. Sponsoring Agency Code Research and Development Center Office of Engineering, Logistics, 1082 Shennecossett Road and Development

Reversible neuronal and muscular toxicity of caffeine in developing vertebrates.

PubMed

Rodriguez, Rufino S; Haugen, Rebecca; Rueber, Alexandra; Huang, Cheng-Chen

2014-06-01

This study utilizes zebrafish embryos to understand the cellular and molecular mechanisms of caffeine toxicity in developing vertebrate embryos. By using a high concentration of caffeine, we observed almost all the phenotypes that have been described in humans and/or in other animal models, including neural tube closure defect, jittery, touch insensitivity, and growth retardation as well as a drastic coiled body phenotype. Zebrafish embryos exposed to 5mM caffeine exhibited high frequent movement, 10 moves/min comparing with around 3 moves/min in control embryos, within half an hour post exposure (HPE). They later showed twitching, uncoordinated movement, and eventually severe body curvature by 6HPE. Exposure at later stages resulted in the same phenotypes but more posteriorly. Surprisingly, when caffeine was removed before 6HPE, the embryos were capable of recovering but still exhibited mild curvature and shorter bodies. Longer exposure caused irreversible body curvature and lethality. These results suggest that caffeine likely targets the neuro-muscular physiology in developing embryos. Immunohistochemistry revealed that the motorneurons in treated embryos developed shorter axons, abnormal branching, and excessive synaptic vesicles. Developing skeletal muscles also appeared smaller and lacked the well-defined boundaries seen in control embryos. Finally, caffeine increases the expression of genes involved in synaptic vesicle migration. In summary, our results provide molecular understanding of caffeine toxicity on developing vertebrate embryos. Published by Elsevier Inc.

Birth of piglets from in vitro-produced, zona-intact porcine embryos vitrified in a closed system

PubMed Central

Men, Hongsheng; Zhao, Chongbei; Wei, Si; Murphy, Clifton N.; Spate, Lee; Liu, Yang; Walters, Eric M.; Samuel, Melissa S.; Prather, Randall S.; Critser, John K.

2011-01-01

As the importance of swine models in biomedical research increases, it is essential to develop low-cost, high-throughput systems to cryopreserve swine germplasm for maintenance of these models. However, porcine embryos are exceedingly sensitive to low temperature and successful cryopreservation is generally limited to the use of vitrification in open systems that allow direct contact of the embryos with liquid nitrogen (LN2). This creates a high risk of pathogen transmission. Therefore, cryopreservation of porcine embryos in a “closed” system is of very high importance. In this study, in vitro-produced (IVP) porcine embryos were used to investigate cryosurvival and developmental potential of embryos cryopreserved in a closed system. Optimal centrifugal forces to completely disassociate intracellular lipids from blastomeres were investigated using Day-4 embryos. Cryosurvival of delipidated embryos was investigated by vitrifying the embryos immediately after centrifugation, or after development to blastocysts. In this study, centrifugation for 30 min at 13,000 g was adequate to completely delipidate the embryos; furthermore, these embryos were able to survive cryopreservation at a rate comparable to those centrifuged for only 12 min. When delipidated embryos were vitrified at the blastocyst stage, there was no difference in survival between embryos vitrified using OPS and 0.25 mL straws. Some embryos vitrified by each method developed to term. These experiments demonstrated that porcine embryos can be cryopreserved in a closed system after externalizing their intracellular lipids. This has important implications for banking swine models of human health and disease. PMID:21458047

A modified culture method significantly improves the development of mouse somatic cell nuclear transfer embryos.

PubMed

Dai, Xiangpeng; Hao, Jie; Zhou, Qi

2009-08-01

Many strategies have been established to improve the efficiency of somatic cell nuclear transfer (SCNT), but relatively few focused on improving culture conditions. The effect of different culture media on preimplantation development of mouse nuclear transfer embryos was investigated. A modified sequential media method, named D media (M16/KSOM and CZB-EG/KSOM), was successfully established that significantly improves SCNT embryo development. Our result demonstrated that while lacking any adverse effect on in vivo fertilized embryos, the D media dramatically improves the blastocyst development of SCNT embryos compared with other commonly used media, including KSOM, M16, CZB, and alphaMEM. Specifically, the rate of blastocyst formation was 62.3% for D1 (M16/KSOM) versus 10-30% for the other media. An analysis of media components indicated that removing EDTA and glutamine from the media can be beneficial for early SCNT embryo development. Our results suggest that in vitro culture environment plays an important role in somatic cell reprogramming, and D media represent the most efficient culture method reported to date to support mouse SCNT early embryo development in vitro.

Metabolic and mitochondrial dysfunction in early mouse embryos following maternal dietary protein intervention.

PubMed

Mitchell, Megan; Schulz, Samantha L; Armstrong, David T; Lane, Michelle

2009-04-01

Dietary supply of nutrients, both periconception and during pregnancy, influence the growth and development of the fetus and offspring and their health into adult life. Despite the importance of research efforts surrounding the developmental origins of health and disease hypothesis, the biological mechanisms involved remain elusive. Mitochondria are of major importance in the oocyte and early embryo, particularly as a source of ATP generation, and perturbations in their function have been related to reduced embryo quality. The present study examined embryo development following periconception exposure of females to a high-protein diet (HPD) or a low-protein diet (LPD) relative to a medium-protein diet (MPD; control), and we hypothesized that perturbed mitochondrial metabolism in the mouse embryo may be responsible for the impaired embryo and fetal development reported by others. Although the rate of development to the blastocyst stage did not differ between diets, both the HPD and LPD reduced the number of inner cell mass cells in the blastocyst-stage embryo. Furthermore, mitochondrial membrane potential was reduced and mitochondrial calcium levels increased in the 2-cell embryo. Embryos from HPD females had elevated levels of reactive oxygen species and ADP concentrations, indicative of metabolic stress and, potentially, the uncoupling of oxidative phosphorylation, whereas embryos from LPD females had reduced mitochondrial clustering around the nucleus, suggestive of an overall quietening of metabolism. Thus, although periconception dietary supply of different levels of protein is permissive of development, mitochondrial metabolism is altered in the early embryo, and the nature of the perturbation differs between HPD and LPD exposure.

[Cryopreservation of mouse embryos in ethylene glycol-based solutions: a search for the optimal and simple protocols].

PubMed

Luo, Ming-Jiu; Liu, Na; Miao, De-Qiang; Lan, Guo-Cheng; Suo-Feng; Chang, Zhong-Le; Tan, Jing-He

2005-09-01

Although ethylene glycol (EG) has been widely used for embryo cryopreservation in domestic animals, few attempts were made to use this molecule to freeze mouse and human embryos. In the few studies that used EG for slow-freezing of mouse and human embryos, complicated protocols for human embryos were used, and the protocols need to be simplified. Besides, freezing mouse morula with EG as a cryoprotectant has not been reported. In this paper, we studied the effects of embryo stages, EG concentration, duration and procedure of equilibration, sucrose supplementation and EG removal after thawing on the development of thawed mouse embryos, using the simple freezing and thawing procedures for bovine embryos. The blastulation and hatching rates (81.92% +/- 2.24% and 68.56% +/- 2.43%, respectively) of the thawed late compact morulae were significantly (P < 0.05) higher than those of embryos frozen-thawed at other stages. When mouse late compact morulae were frozen with different concentrations of EG, the highest rates of blastocyst formation and hatching were obtained with 1.8mol/L EG. The blastulation rate was significantly higher when late morulae were equilibrated in 1.8 mol/L EG for 10 min prior to freezing than when they were equilibrated for 30 min, and the hatching rate of embryos exposed to EG for 10 min was significantly higher than that of embryos exposed for 20 and 30 min. Both rates of blastocyst formation and hatching obtained with two-step equilibration were higher (P < 0.05) than with one-step equilibration in 1.8 mol/L EG. Addition of sucrose to the EG-based solution had no beneficial effects. On the contrary, an increased sucrose level (0.4 mol/L) in the solution impaired the development of the frozen-thawed embryos. In contrast, addition of 0.1 mol/L sucrose to the propylene glycol (PG)-based solution significantly improved the development of the frozen-thawed embryos. Elimination of the cryoprotectant after thawing did not improve the development of the thawed embryos. The cell numbers were less (P < 0.05) in blastocysts developed from the thawed morulae than in the in vivo derived ones. In summary, embryo stage, EG concentration, duration and procedure of equilibration and sucrose supplementation had marked effects on development of the thawed mouse embryos, and a protocol for cryopreservation of mouse embryos is recommended in which the late morulae are frozen in 1.8 mol/L EG using the simple freezing and thawing procedures of bovine embryos after a two-step equilibration and the embryos can be cultured or transferred without EG removal after thawing.

O-polysaccharide is important for Salmonella Pullorum survival in egg albumen, and virulence and colonization in chicken embryos.

PubMed

Guo, Rongxian; Li, Zhuoyang; Jiao, Yang; Geng, Shizhong; Pan, Zhiming; Chen, Xiang; Li, Qiuchun; Jiao, Xinan

2017-10-01

The pathogen Salmonella Pullorum is the causative agent of persistent systemic infection of poultry, leading to economic losses in developing countries due to morbidity, mortality and reduction in egg production. These infections may result in vertical transmission to eggs or progeny. Limited information is available regarding the mechanisms involved in the survival of Salmonella Pullorum in egg albumen and developing chicken embryos. Hence, we investigated the role of O-polysaccharide in the contamination of eggs and the colonization of chicken embryos. Compared with the wild-type strain, the isogenic waaL mutant exhibited an O-antigen-deficient rough phenotype, and increased sensitivity to egg albumen and chicken serum, as well as reduced adherence to DF-1 cells. Infection with Salmonella Pullorum lacking O-polysaccharide resulted in significantly reduced embryo lethality and bacterial colonization. These results suggest that O-polysaccharide is essential for Salmonella Pullorum colonization in eggs, both post-lay and developing embryos. The chicken embryo infection model could be used to characterize the interaction between Salmonella Pullorum and developing embryos, and it will also contribute to the development of more rational vaccines to protect laying hens and embryos.

Preimplantation death of xenomitochondrial mouse embryo harbouring bovine mitochondria

PubMed Central

Kawahara, Manabu; Koyama, Shiori; Iimura, Satomi; Yamazaki, Wataru; Tanaka, Aiko; Kohri, Nanami; Sasaki, Keisuke; Takahashi, Masashi

2015-01-01

Mitochondria, cellular organelles playing essential roles in eukaryotic cell metabolism, are thought to have evolved from bacteria. The organization of mtDNA is remarkably uniform across species, reflecting its vital and conserved role in oxidative phosphorylation (OXPHOS). Our objectives were to evaluate the compatibility of xenogeneic mitochondria in the development of preimplantation embryos in mammals. Mouse embryos harbouring bovine mitochondria (mtB-M embryos) were prepared by the cell-fusion technique employing the haemagglutinating virus of Japan (HVJ). The mtB-M embryos showed developmental delay at embryonic days (E) 3.5 after insemination. Furthermore, none of the mtB-M embryos could implant into the maternal uterus after embryo transfer, whereas control mouse embryos into which mitochondria from another mouse had been transferred developed as well as did non-manipulated embryos. When we performed quantitative PCR (qPCR) of mouse and bovine ND5, we found that the mtB-M embryos contained 8.3% of bovine mitochondria at the blastocyst stage. Thus, contamination with mitochondria from another species induces embryonic lethality prior to implantation into the maternal uterus. The heteroplasmic state of these xenogeneic mitochondria could have detrimental effects on preimplantation development, leading to preservation of species-specific mitochondrial integrity in mammals. PMID:26416548

Digital Microfluidic Dynamic Culture of Mammalian Embryos on an Electrowetting on Dielectric (EWOD) Chip

PubMed Central

Huang, Hong-Yuan; Shen, Hsien-Hua; Tien, Chang-Hung; Li, Chin-Jung; Fan, Shih-Kang; Liu, Cheng-Hsien; Hsu, Wen-Syang; Yao, Da-Jeng

2015-01-01

Current human fertilization in vitro (IVF) bypasses the female oviduct and manually inseminates, fertilizes and cultivates embryos in a static microdrop containing appropriate chemical compounds. A microfluidic microchannel system for IVF is considered to provide an improved in-vivo-mimicking environment to enhance the development in a culture system for an embryo before implantation. We demonstrate a novel digitalized microfluidic device powered with electrowetting on a dielectric (EWOD) to culture an embryo in vitro in a single droplet in a microfluidic environment to mimic the environment in vivo for development of the embryo and to culture the embryos with good development and live births. Our results show that the dynamic culture powered with EWOD can manipulate a single droplet containing one mouse embryo and culture to the blastocyst stage. The rate of embryo cleavage to a hatching blastocyst with a dynamic culture is significantly greater than that with a traditional static culture (p<0.05). The EWOD chip enhances the culture of mouse embryos in a dynamic environment. To test the reproductive outcome of the embryos collected from an EWOD chip as a culture system, we transferred embryos to pseudo-pregnant female mice and produced live births. These results demonstrate that an EWOD-based microfluidic device is capable of culturing mammalian embryos in a microfluidic biological manner, presaging future clinical application. PMID:25933003

Digital Microfluidic Dynamic Culture of Mammalian Embryos on an Electrowetting on Dielectric (EWOD) Chip.

PubMed

Huang, Hong-Yuan; Shen, Hsien-Hua; Tien, Chang-Hung; Li, Chin-Jung; Fan, Shih-Kang; Liu, Cheng-Hsien; Hsu, Wen-Syang; Yao, Da-Jeng

2015-01-01

Current human fertilization in vitro (IVF) bypasses the female oviduct and manually inseminates, fertilizes and cultivates embryos in a static microdrop containing appropriate chemical compounds. A microfluidic microchannel system for IVF is considered to provide an improved in-vivo-mimicking environment to enhance the development in a culture system for an embryo before implantation. We demonstrate a novel digitalized microfluidic device powered with electrowetting on a dielectric (EWOD) to culture an embryo in vitro in a single droplet in a microfluidic environment to mimic the environment in vivo for development of the embryo and to culture the embryos with good development and live births. Our results show that the dynamic culture powered with EWOD can manipulate a single droplet containing one mouse embryo and culture to the blastocyst stage. The rate of embryo cleavage to a hatching blastocyst with a dynamic culture is significantly greater than that with a traditional static culture (p<0.05). The EWOD chip enhances the culture of mouse embryos in a dynamic environment. To test the reproductive outcome of the embryos collected from an EWOD chip as a culture system, we transferred embryos to pseudo-pregnant female mice and produced live births. These results demonstrate that an EWOD-based microfluidic device is capable of culturing mammalian embryos in a microfluidic biological manner, presaging future clinical application.

Applying embryo cryopreservation technologies to the production of domestic and black-footed cats.

PubMed

Pope, C E; Gómez, M C; Galiguis, J; Dresser, B l

2012-12-01

Our objectives were (i) compare in vitro development of early cleavage stage domestic cat embryos after cryopreservation by minimal volume vitrification vs a standard slow, controlled-rate method, (ii) determine viability of vitrified domestic cat embryos by oviductal transfer into synchronous recipients and (iii) evaluate in vivo survival of black-footed cat (BFC, Felis nigripes) embryos after intra- and inter-species transfer. In vitro-derived (IVM/IVF) cat embryos were used to evaluate in vitro development after controlled-rate cryopreservation vs vitrification vs controls. Blastocyst development was similar in both groups of cryopreserved embryos (22-26%), but it was lower (p < 0.05) than that of fresh embryos (50%). After embryo transfer, four of eight recipients of vitrified embryos established pregnancies--three of six (50%) and one of two (50%) that received embryos from in vivo- and in vitro-matured oocytes, respectively. Three male and two female kittens weighing from 51 to 124 g (mean = 88 g) were delivered on days 61-65 of gestation. In BFC, four intra-species embryo transfer procedures were carried out--two recipients received fresh day 2 embryos (n = 5, 8) and two recipients received embryos that had been cryopreserved on day 1 (n = 6) or 2 (n = 8). A 2-year-old recipient of cryopreserved embryos established pregnancy and delivered two live male kittens. Subsequently, five cryopreserved BFC embryos were transferred to a domestic cat recipient. On day 29, the recipient was determined to be pregnant and delivered naturally a live, healthy female BFC kitten on day 66. In summary, in vivo survival of vitrified domestic cat embryos was shown by the births of kittens after transfer into recipients. Also, we demonstrated that sperm and embryo cryopreservation could be combined with intra- and inter-species embryo transfer and integrated into the array of assisted reproductive techniques used successfully for propagation of a rare and vulnerable felid species, the black-footed cat. © 2012 Blackwell Verlag GmbH.

Transition of cell numbers in bovine preimplantation embryos: in vivo collected and in vitro produced embryos.

PubMed

Ushijima, Hitoshi; Akiyama, Kiyoshi; Tajima, Toshio

2008-08-01

The total cell numbers (TCNs) of bovine embryos collected from superovulated donors (VIVO embryos) were counted 0-9 d after ovulation to quantify the developmental process. Using numerical analysis of embryo development, we also compared the developmental process of VIVO embryos, in vitro-fertilized (IVF) embryos and nuclear transfer (NT) embryos obtained from enucleated oocytes and blastomere nuclei. The TCNs of embryos were measured using the air-dry method. Cleavage divisions (CD) of the embryos were obtained using logarithmic transformation of the TCN. The TCN of the VIVO embryos increased significantly (P<0.001) with time. The relationship between the CD of the VIVO embryos at 0-9 d after ovulation and age in days was described by a linear equation with a high correlation (y=1.03x+0.16, r=0.99), showing that CD occurs about once each day for all blastomeres. However, compared to the VIVO embryos, the TCN of the IVF embryos did not increase from 3-4 d nor after 7 d; the TCN of the NT embryos did not increase after 7 d (P>0.05). The results suggest a delay in development at these developmental stages. The slopes of regression lines of the IVF and NT embryos were significantly (P<0.001) smaller, indicating that quantification of the developmental process of VIVO embryos according to TCN and CD would be useful as criteria for numerical evaluation of the developmental process of bovine in vitro produced embryos.

PreImplantation factor (PIF) protects cultured embryos against oxidative stress: relevance for recurrent pregnancy loss (RPL) therapy.

PubMed

Goodale, Lindsay F; Hayrabedran, Soren; Todorova, Krassimira; Roussev, Roumen; Ramu, Sivakumar; Stamatkin, Christopher; Coulam, Carolyn B; Barnea, Eytan R; Gilbert, Robert O

2017-05-16

Recurrent pregnancy loss (RPL) affects 2-3% of couples. Despite a detailed work-up, the etiology is frequently undefined, leading to non-targeted therapy. Viable embryos and placentae express PreImplantation Factor (PIF). Maternal circulating PIF regulates systemic immunity and reduces circulating natural killer cells cytotoxicity in RPL patients. PIF promotes singly cultured embryos' development while anti-PIF antibody abrogates it. RPL serum induced embryo toxicity is negated by PIF. We report that PIF rescues delayed embryo development caused by <3 kDa RPL serum fraction likely by reducing reactive oxygen species (ROS). We reveal that protein disulfide isomerase/thioredoxin (PDI/TRX) is a prime PIF target in the embryo, rendering it an important ROS scavenger. The 16F16-PDI/TRX inhibitor drastically reduced blastocyst development while exogenous PIF increased >2 fold the number of embryos reaching the blastocyst stage. Mechanistically, PDI-inhibitor preferentially binds covalently to oxidized PDI over its reduced form where PIF avidly binds. PIF by targeting PDI/TRX at a distinct site limits the inhibitor's pro-oxidative effects. The >3kDa RPL serum increased embryo demise by three-fold, an effect negated by PIF. However, embryo toxicity was not associated with the presence of putative anti-PIF antibodies. Collectively, PIF protects cultured embryos both against ROS, and higher molecular weight toxins. Using PIF for optimizing in vitro fertilization embryos development and reducing RPL is warranted.

The first cell-fate decisions in the mouse embryo: destiny is a matter of both chance and choice.

PubMed

Zernicka-Goetz, Magdalena

2006-08-01

Development of the early mouse embryo has always been classified as regulative, meaning that when parts or blastomeres of the embryo are isolated they change their developmental fate and can even reconstruct the whole. However, regulative development does not mean that, in situ, these parts or blastomeres are equivalent; it does not mean that the early mammalian embryo is a ball of identical cells without any bias. Regulative development simply means that whatever bias the regions of the embryo might have they still remain flexible and can respond to experimental interference by changes of fate. This realization -- that regulative development and patterning can co-exist -- has led to a renaissance of interest in the first days of development of the mouse embryo, and several laboratories have provided evidence for some early bias. Now the challenge is to gain some understanding of the molecular basis of this bias.

Metabolomic Assessment of Embryo Viability

PubMed Central

Uyar, Asli; Seli, Emre

2014-01-01

Preimplantation embryo metabolism demonstrates distinctive characteristics associated with the developmental potential of embryos. On this basis, metabolite content of culture media was hypothesized to reflect the implantation potential of individual embryos. This hypothesis was tested in consecutive studies reporting a significant association between culture media metabolites and embryo development or clinical pregnancy. The need for a noninvasive, reliable, and rapid embryo assessment strategy promoted metabolomics studies in vitro fertilization (IVF) in an effort to increase success rates of single embryo transfers. With the advance of analytical techniques and bioinformatics, commercial instruments were developed to predict embryo viability using spectroscopic analysis of surplus culture media. However, despite the initial promising results from proof-of-principal studies, recent randomized controlled trials using commercial instruments failed to show a consistent benefit in improving pregnancy rates when metabolomics is used as an adjunct to morphology. At present, the application of metabolomics technology in clinical IVF laboratory requires the elimination of factors underlying inconsistent findings, when possible, and development of reliable predictive models accounting for all possible sources of bias throughout the embryo selection process. PMID:24515909

The Unmanned Initiative: A Strategic Appraisal of Coast Guard Unmanned Aerial Systems

DTIC Science & Technology

2011-06-01

King also designated the Coast Guard as the service responsible for helicopter training, research and development. With no established training...Guard Deepwater Acquisition Programs,” Congressional Research Service (Washington, DC, Mar 30, 2010), 25. 15 U.S. Coast Guard, Land-Based UAS, 1-4...preproduction and research , the Coast Guard terminated its UAS program, citing “development risks and a lack of funding.”17 The lack of a cutter-based UAS

Assessing embryo development using swept source optical coherence tomography

NASA Astrophysics Data System (ADS)

Caujolle, S.; Cernat, R.; Silvestri, G.; Marques, M. J.; Bradu, A.; Feuchter, T.; Robinson, G.; Griffin, D.; Podoleanu, A.

2018-03-01

A detailed assessment of embryo development would assist biologists with selecting the most suitable embryos for transfer leading to higher pregnancy rates. Currently, only low resolution microscopy is employed to perform this assessment. Although this method delivers some information on the embryo surface morphology, no specific details are shown related to its inner structure. Using a Master-Slave Swept-Source Optical Coherence Tomography (SS-OCT), images of bovine embryos from day 7 after fertilization were collected from different depths. The dynamic changes inside the embryos were examined, in detail and in real-time from several depths. To prove our ability to characterize the morphology, a single embryo was imaged over 26 hours. The embryo was deprived of its life support environment, leading to its death. Over this period, clear morphological changes were observed.

Early embryo development in Fucus distichus is auxin sensitive

NASA Technical Reports Server (NTRS)

Basu, Swati; Sun, Haiguo; Brian, Leigh; Quatrano, Ralph L.; Muday, Gloria K.

2002-01-01

Auxin and polar auxin transport have been implicated in controlling embryo development in land plants. The goal of these studies was to determine if auxin and auxin transport are also important during the earliest stages of development in embryos of the brown alga Fucus distichus. Indole-3-acetic acid (IAA) was identified in F. distichus embryos and mature tissues by gas chromatography-mass spectroscopy. F. distichus embryos accumulate [(3)H]IAA and an inhibitor of IAA efflux, naphthylphthalamic acid (NPA), elevates IAA accumulation, suggesting the presence of an auxin efflux protein complex similar to that found in land plants. F. distichus embryos normally develop with a single unbranched rhizoid, but growth on IAA leads to formation of multiple rhizoids and growth on NPA leads to formation of embryos with branched rhizoids, at concentrations that are active in auxin accumulation assays. The effects of IAA and NPA are complete before 6 h after fertilization (AF), which is before rhizoid germination and cell division. The maximal effects of IAA and NPA are between 3.5 and 5 h AF and 4 and 5.5 h AF, respectively. Although, the location of the planes of cell division was significantly altered in NPA- and IAA-treated embryos, these abnormal divisions occurred after abnormal rhizoid initiation and branching was observed. The results of this study suggest that auxin acts in the formation of apical basal patterns in F. distichus embryo development.

Nuclear-mitochondrial incompatibility in interorder rhesus monkey-cow embryos derived from somatic cell nuclear transfer.

PubMed

Kwon, Daekee; Koo, Ok-Jae; Kim, Min-Jung; Jang, Goo; Lee, Byeong Chun

2016-10-01

Monkey interorder somatic cell nuclear transfer (iSCNT) using enucleated cow oocytes yielded poor blastocysts development and contradictory results among research groups. Determining the reason for this low blastocyst development is a prerequisite for optimizing iSCNT in rhesus monkeys. The aim of this study was to elucidate nuclear-mitochondrial incompatibility of rhesus monkey-cow iSCNT embryos and its relationship to low blastocyst development. Cytochrome b is a protein of complex III of the electron transport chain (ETC). According to meta-analysis of amino acid sequences, the homology of cytochrome b is 75 % between rhesus monkeys and cattle. To maintain the function of ETC after iSCNT, 4n iSCNT embryos were produced by fusion of non-enucleated cow oocytes and rhesus monkey somatic cells. The blastocyst development rate of 4n iSCNT embryos was higher than that of 2n embryos (P < 0.01). Formation of reactive oxygen species (ROS) is an indirect indicator of ETC activity of cells. The ROS levels of 4n iSCNT embryos was higher than that of 2n embryos (P < 0.01). Collectively, rhesus monkey iSCNT embryos reconstructed with cow oocytes have nuclear-mitochondrial incompatibility due to fundamental species differences between rhesus monkeys and cattle. Nuclear-mitochondrial incompatibility seems to correlate with low ETC activity and extremely low blastocyst development of rhesus monkey-cow iSCNT embryos.

Maternally derived trypsin may have multiple functions in the early development of turbot (Scopthalmus maximus).

PubMed

Chi, Liang; Liu, Qinghua; Xu, Shihong; Xiao, Zhizhong; Ma, Daoyuan; Li, Jun

2015-10-01

Trypsin is an important serine protease that is considered to be involved in digestion of protein in teleost fish. Nevertheless, studies on trypsin/trypsinogen in fish embryos are very limited. In this study, the trypsinogen of turbot (Scophthalmus maximus) (tTG) was identified and the expression patterns and activity of trypsinogen/trypsin were investigated. The results showed that the tTG mRNA was evenly distributed in the oocytes and was also expressed along the yolk periphery in early embryos. At later embryo stages and 1 days after hatching (dph), the tTG mRNA concentrated at the alimentary tract and head. Quantitative expression analysis showed that the tTG transcripts decreased after fertilization until the gastrula stage, then increased with the embryo and larvae development. This result was also confirmed by the specific activity analysis of trypsin and in-situ-hybridization (ISH). All of the results indicated that tTG in early embryo stages was maternally derived and expressed by itself after gastrula stages. Additionally, location of tTG mRNA in embryos and larvae was investigated; we considered that trypsin may have multiple functions during the embryo development process. Based on our results regarding trypsinogen in embryos and early development, we concluded that the trypsin/trypsinogen in turbot embryos was inherited from a maternal source and we suggested that trypsin in early development has multiple functions in the process of development. Copyright © 2015 Elsevier Inc. All rights reserved.

Sex determination of duck embryos: observations on syrinx development

USGS Publications Warehouse

Wilson, Robert E.; Sonsthagen, Sarah A.; Franson, J. Christian

2013-01-01

Ducks exhibit sexual dimorphism in vocal anatomy. Asymmetrical ossification of the syrinx (bulla syringealis) is discernable at about 10 days of age in male Pekin duck (Anas platyrhynchos domestica) embryos, but information is lacking on the early development of the bulla in wild ducks. To evaluate the reliability of this characteristic for sexing developing embryos, we examined the syrinx of dead embryos and compared results with molecular sexing techniques in high arctic nesting Common Eiders (Somateria mollissima). Embryos 8 days or older were accurately (100%) sexed based on the presence/absence of a bulla, 2 days earlier than Pekin duck. The use of the tracheal bulla can be a valuable technique when sex identification of embryos or young ducklings is required.

Growth and development of cultured carrot cells and embryos under spaceflight conditions

NASA Technical Reports Server (NTRS)

Krikorian, A. D.; Dutcher, F. R.; Quinn, C. E.; Steward, F. C.

1981-01-01

Morphogenetically competent proembryonic cells and well-developed somatic embryos of carrot at two levels of organization were exposed for 18.5 days to a hypogravity environment aboard the Soviet Biosatellite Cosmos 1129. It was confirmed that cultured totipotent cells of carrot can give rise to embryos with well-developed roots and minimally developed shoots. It was also shown that the space hypogravity environment could support the further growth of already-organized, later somatic embryonic stages and give rise to fully developed embryo-plantlets with roots and shoots.

9 CFR 98.11 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth... Health Inspection Service of the United States Department of Agriculture. Collection of embryos. Embryos removed from a single donor dam in one operation. Embryo. The initial stages of development of an animal...

9 CFR 98.11 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth... Health Inspection Service of the United States Department of Agriculture. Collection of embryos. Embryos removed from a single donor dam in one operation. Embryo. The initial stages of development of an animal...

9 CFR 98.11 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth... Health Inspection Service of the United States Department of Agriculture. Collection of embryos. Embryos removed from a single donor dam in one operation. Embryo. The initial stages of development of an animal...

Media composition: salts and osmolality.

PubMed

Baltz, Jay M

2012-01-01

The main components of embryo culture media are salts, which dissociate into their component inorganic ions in aqueous solution. All embryo culture media contain the same six inorganic ions: Na(+), K(+), Cl(-), Ca(2+), Mg(2+), and SO(4)(2-), while most also contain PO(4)(2-). The salts that are used to formulate embryo culture media can be traced back to classic saline solutions, particularly Krebs-Ringer Bicarbonate (KRB), that were developed for somatic cells in the first half of the twentieth century. The salt and inorganic ion concentrations in the first successful defined mouse embryo culture medium, Whittens medium, were identical to those in KRB. These remained largely unchanged in embryo culture media for decades, with similar levels found in the standard mouse embryo culture medium, M16, formulated in the 1970s. Human embryos were initially cultured in undefined somatic cell media such as Earles and Hams F-10 with serum added. This changed in the mid-1980s, however, with the development of Quinns HTF, a defined medium specifically formulated for human embryo culture, in which the inorganic ion concentrations are similar to those in M16 and Whittens. While these media were useful both for experimental work and clinically, embryos suffered developmental blocks in all of them, with mouse embryos blocking at the 2-cell stage and human embryos at the 4- to 8-cell stage. Starting in the late 1980s, however, mouse embryo culture media were first developed that alleviated these developmental blocks. These media, CZB and KSOM, had much lower osmolalities than previous media, mainly due to lower inorganic ion concentrations. Indeed, lowering total inorganic ion concentration and osmolality proved key to understanding how media that supported complete preimplantation development in vitro can be formulated. A subsequent improvement was the addition of amino acids to culture media for both mouse and human embryos. At least in part, their beneficial effect during the cleavage stages of development is due to the presence in early preimplantation embryos of mechanisms for cell volume regulation that depend on the accumulation of amino acids as organic osmolytes to provide intracellular osmotic support. These amino acids, principally glycine, replace a portion of the intracellular inorganic ions that would otherwise be needed to maintain cell size, preventing the intracellular ionic strength from rising to deleterious levels and blocking development. Thus, the optimum salts levels, osmolality, and amino acid contents of culture media are not independent, but interact strongly because of their roles in cell volume regulation. In the absence of compounds that preimplantation embryos can use as organic osmolytes, embryos will develop only at lower osmolalities and salt concentrations in the medium. However, when organic osmolytes such as some amino acids are present, embryos will develop in culture at higher osmolarities that are similar to those they experience in tubal fluid in vivo.

Improved Murine Blastocyst Quality and Development in a Single Culture Medium Compared to Sequential Culture Media

PubMed Central

Hennings, Justin M.; Zimmer, Randall L.; Nabli, Henda; Davis, J. Wade; Sutovsky, Peter; Sutovsky, Miriam; Sharpe-Timms, Kathy L.

2015-01-01

Objective: Validate single versus sequential culture media for murine embryo development. Design: Prospective laboratory experiment. Setting: Assisted Reproduction Laboratory. Animals: Murine embryos. Interventions: Thawed murine zygotes cultured for 3 or 5 days (d3 or d5) in single or sequential embryo culture media developed for human in vitro fertilization. Main Outcome Measures: On d3, zygotes developing to the 8 cell (8C) stage or greater were quantified using 4’,6-diamidino-2-phenylindole (DAPI), and quality was assessed by morphological analysis. On d5, the number of embryos reaching the blastocyst stage was counted. DAPI was used to quantify total nuclei and inner cell mass nuclei. Localization of ubiquitin C-terminal hydrolase L1 (UCHL1) and ubiquitin C-terminal hydrolase L3 (UCHL3) was reference points for evaluating cell quality. Results: Comparing outcomes in single versus to sequential media, the odds of embryos developing to the 8C stage on d3 were 2.34 time greater (P = .06). On d5, more embryos reached the blastocyst stage (P = <.0001), hatched, and had significantly more trophoblast cells (P = .005) contributing to the increased total cell number. Also at d5, localization of distinct cytoplasmic UCHL1 and nuclear UCHL3 was found in high-quality hatching blastocysts. Localization of UCHL1 and UCHL3 was diffuse and inappropriately dispersed throughout the cytoplasm in low-quality nonhatching blastocysts. Conclusions: Single medium yields greater cell numbers, an increased growth rate, and more hatching of murine embryos. Cytoplasmic UCHL1 and nuclear UHCL3 localization patterns were indicative of embryo quality. Our conclusions are limited to murine embryos but one might speculate that single medium may also be more beneficial for human embryo culture. Human embryo studies are needed. PMID:26668049

Improved Murine Blastocyst Quality and Development in a Single Culture Medium Compared to Sequential Culture Media.

PubMed

Hennings, Justin M; Zimmer, Randall L; Nabli, Henda; Davis, J Wade; Sutovsky, Peter; Sutovsky, Miriam; Sharpe-Timms, Kathy L

2016-03-01

Validate single versus sequential culture media for murine embryo development. Prospective laboratory experiment. Assisted Reproduction Laboratory. Murine embryos. Thawed murine zygotes cultured for 3 or 5 days (d3 or d5) in single or sequential embryo culture media developed for human in vitro fertilization. On d3, zygotes developing to the 8 cell (8C) stage or greater were quantified using 4',6-diamidino-2-phenylindole (DAPI), and quality was assessed by morphological analysis. On d5, the number of embryos reaching the blastocyst stage was counted. DAPI was used to quantify total nuclei and inner cell mass nuclei. Localization of ubiquitin C-terminal hydrolase L1 (UCHL1) and ubiquitin C-terminal hydrolase L3 (UCHL3) was reference points for evaluating cell quality. Comparing outcomes in single versus to sequential media, the odds of embryos developing to the 8C stage on d3 were 2.34 time greater (P = .06). On d5, more embryos reached the blastocyst stage (P = <.0001), hatched, and had significantly more trophoblast cells (P = .005) contributing to the increased total cell number. Also at d5, localization of distinct cytoplasmic UCHL1 and nuclear UCHL3 was found in high-quality hatching blastocysts. Localization of UCHL1 and UCHL3 was diffuse and inappropriately dispersed throughout the cytoplasm in low-quality nonhatching blastocysts. Single medium yields greater cell numbers, an increased growth rate, and more hatching of murine embryos. Cytoplasmic UCHL1 and nuclear UHCL3 localization patterns were indicative of embryo quality. Our conclusions are limited to murine embryos but one might speculate that single medium may also be more beneficial for human embryo culture. Human embryo studies are needed. © The Author(s) 2015.

Auxin polar transport is essential for the development of zygote and embryo in Nicotiana tabacum L. and correlated with ABP1 and PM H+-ATPase activities

PubMed Central

Chen, Dan; Ren, Yujun; Deng, Yingtian; Zhao, Jie

2010-01-01

Auxin is an important plant growth regulator, and plays a key role in apical–basal axis formation and embryo differentiation, but the mechanism remains unclear. The level of indole-3-acetic acid (IAA) during zygote and embryo development of Nicotiana tabacum L. is investigated here using the techniques of GC-SIM-MS analysis, immunolocalization, and the GUS activity assay of DR5::GUS transgenic plants. The distribution of ABP1 and PM H+-ATPase was also detected by immunolocalization, and this is the first time that integral information has been obtained about their distribution in the zygote and in embryo development. The results showed an increase in IAA content in ovules and the polar distribution of IAA, ABP1, and PM H+-ATPase in the zygote and embryo, specifically in the top and basal parts of the embryo proper (EP) during proembryo development. For information about the regulation mechanism of auxin, an auxin transport inhibitor TIBA (2,3,5-triiodobenzoic acid) and exogenous IAA were, respectively, added to the medium for the culture of ovules at the zygote and early proembryo stages. Treatment with a suitable IAA concentration promoted zygote division and embryo differentiation, while TIBA treatment obviously suppressed these processes and caused the formation of abnormal embryos. The distribution patterns of IAA, ABP1, and PM H+-ATPase were also disturbed in the abnormal embryos. These results indicate that the polar distribution and transport of IAA begins at the zygote stage, and affects zygote division and embryo differentiation in tobacco. Moreover, ABP1 and PM H+-ATPase may play roles in zygote and embryo development and may also be involved in IAA signalling transduction. PMID:20348352

Silver nanoparticles induce developmental stage-specific embryonic phenotypes in zebrafish.

PubMed

Lee, Kerry J; Browning, Lauren M; Nallathamby, Prakash D; Osgood, Christopher J; Xu, Xiao-Hong Nancy

2013-12-07

Much is anticipated from the development and deployment of nanomaterials in biological organisms, but concerns remain regarding their biocompatibility and target specificity. Here we report our study of the transport, biocompatibility and toxicity of purified and stable silver nanoparticles (Ag NPs, 13.1 ± 2.5 nm in diameter) upon the specific developmental stages of zebrafish embryos using single NP plasmonic spectroscopy. We find that single Ag NPs passively diffuse into five different developmental stages of embryos (cleavage, early-gastrula, early-segmentation, late-segmentation, and hatching stages), showing stage-independent diffusion modes and diffusion coefficients. Notably, the Ag NPs induce distinctive stage and dose-dependent phenotypes and nanotoxicity, upon their acute exposure to the Ag NPs (0-0.7 nM) for only 2 h. The late-segmentation embryos are most sensitive to the NPs with the lowest critical concentration (CNP,c < 0.02 nM) and highest percentages of cardiac abnormalities, followed by early-segmentation embryos (CNP,c < 0.02 nM), suggesting that disruption of cell differentiation by the NPs causes the most toxic effects on embryonic development. The cleavage-stage embryos treated with the NPs develop into a wide variety of phenotypes (abnormal finfold, tail/spinal cord flexure, cardiac malformation/edema, yolk sac edema, and acephaly). These organ structures are not yet developed in cleavage-stage embryos, suggesting that the earliest determinative events to create these structures are ongoing, and disrupted by NPs, which leads to the downstream effects. In contrast, the hatching embryos are most resistant to the Ag NPs, and majority of embryos (94%) develop normally, and none of them develop abnormally. Interestingly, early-gastrula embryos are less sensitive to the NPs than cleavage and segmentation stage embryos, and do not develop abnormally. These important findings suggest that the Ag NPs are not simple poisons, and they can target specific pathways in development, and potentially enable target specific study and therapy for early embryonic development.

Transcriptional regulators TRIM28, SETDB1, and TP53 are aberrantly expressed in porcine embryos produced by in vitro fertilization in comparison to in vivo- and somatic-cell nuclear transfer-derived embryos

PubMed Central

Hamm, Jennifer; Tessanne, Kim; Murphy, Clifton N; Prather, Randall S

2014-01-01

In vitro embryo production is important for research in animal reproduction, embryo transfer, transgenics, and cloning. Yet, in vitro-fertilized (IVF) embryos are generally developmentally delayed and are inferior to in vivo-derived (IVV) embryos; this discrepancy is likely a result of aberrant gene expression. Transcription of three genes implicated to be important in normal preimplantation embryo development, TRIM28, SETDB1, and TP53, was determined by quanitative PCR in IVF, somatic-cell nuclear transfer (SCNT), parthenogenetic, and IVV porcine oocytes and embryos. There was no difference in TRIM28 or SETDB1 abundance between oocytes matured in vitro versus in vivo (P > 0.05), whereas TP53 levels were higher in in vitro-matured oocytes. TRIM28 increased from metaphase-II oocytes to the 4-cell and blastocyst stages in IVF embryos, whereas IVV embryos showed a reduction in TRIM28 abundance from maturation throughout development. The relative abundance of TP53 increased by the blastocyst stage in all treatment groups, but was higher in IVF embryos compared to IVV and SCNT embryos. In contrast, SETDB1 transcript levels decreased from the 2-cell to blastocyst stage in all treatments. For each gene analyzed, SCNT embryos of both hard-to-clone and easy-to-clone cell lines were more comparable to IVV than IVF embryos. Knockdown of TRIM28 also had no effect on blastocyst development or expression of SETDB1 or TP53. Thus, TRIM28, SETDB1, and TP53 are dynamically expressed in porcine oocytes and embryos. Furthermore, TRIM28 and TP53 abundances in IVV and SCNT embryos are similar, but different from quantities in IVF embryos. Mol. Reprod. Dev. 81: 552–556, 2014. © 2014 The Authors. Published by Wiley Periodicals, Inc. PMID:24659575

Relationships between oxygen consumption rate, viability, and subsequent development of in vivo-derived porcine embryos.

PubMed

Sakagami, N; Nishida, K; Akiyama, K; Abe, H; Hoshi, H; Suzuki, C; Yoshioka, K

2015-01-01

Oxygen consumption rate of in vivo-derived porcine embryos was measured, and its value as an objective method for the assessment of embryo quality was evaluated. Embryos were surgically collected 5 or 6 days after artificial insemination (AI), and oxygen consumption rate of embryos was measured using an embryo respirometer. The average oxygen consumption rate (F × 10(14)/mol s(-1)) of the embryos that developed to the compacted morula stage on Day 5 (Day 0 = the day of artificial insemination) was 0.58 ± 0.03 (mean ± standard error of the mean). The Day-6 embryos had consumption rates of 0.56 ± 0.13, 0.87 ± 0.06, and 1.13 ± 0.07 at the early blastocyst, blastocyst, and expanded blastocyst stages, respectively, showing a gradual increase as the embryos developed. Just after collection, the average oxygen consumption rates of embryos that hatched and of those that did not hatch after culture were 0.60 ± 0.04 and 0.50 ± 0.04 for Day 5 (P = 0.08) and 1.05 ± 0.09 and 0.77 ± 0.05 for Day 6 (P < 0.05), respectively. The value and probability of discrimination by measuring the oxygen consumption rates of embryos to predict their hatching ability after culture were 0.56 and 63.6% for Day-5 embryos and 0.91 and 68.4% for Day-6 blastocysts, respectively. When Day-5 embryos were classified based on the oxygen consumption rate and then transferred non-surgically to recipient sows, three of the seven sows, to which embryos having a high oxygen consumption rate (≥ 0.59) were transferred, became pregnant and farrowed a total of 20 piglets. However, none of the four sows, to which embryos having low oxygen consumption rate (< 0.59) were transferred, became pregnant. These results suggest that the viability of in vivo-derived porcine embryos and subsequent development can be estimated by measuring the oxygen consumption rate. Copyright © 2015 Elsevier Inc. All rights reserved.

Developmental competence of equine oocytes and embryos obtained by in vitro procedures ranging from in vitro maturation and ICSI to embryo culture, cryopreservation and somatic cell nuclear transfer.

PubMed

Galli, C; Colleoni, S; Duchi, R; Lagutina, I; Lazzari, G

2007-03-01

Development of assisted reproductive technologies in horses has been relatively slow compared to other domestic species, namely ruminants and pigs. The scarce availability of abattoir ovaries and the lack of interest from horse breeders and breed associations have been the main reasons for this delay. Progressively though, the technology of oocyte maturation in vitro has been established followed by the application of ICSI to achieve fertilization in vitro. Embryo culture was initially performed in vivo, in the mare oviduct or in the surrogate sheep oviduct, to achieve the highest embryo development, in the range of 18-36% of the fertilised oocytes. Subsequently, the parallel improvement of in vitro oocyte maturation conditions and embryo culture media has permitted high rates of embryo development from in vitro matured and in vitro cultured ICSI embryos, ranging from 5 to 10% in the early studies to up to 38% in the latest ones. From 2003, with the birth of the first cloned equids, the technology of somatic cell nuclear transfer has also become established due to improvement of the basic steps of embryo production in vitro, including cryopreservation. Pregnancy and foaling rates are still estimated based on a small number of in vitro produced equine embryos transferred to recipients. The largest set of data on non-surgical embryo transfer of in vitro produced embryos, from ICSI of both abattoir and in vitro-matured Ovum Pick Up (OPU) oocytes, and from somatic cell nuclear transfer, has been obtained in our laboratory. The data demonstrate that equine embryos produced by OPU and then cryopreserved can achieve up to 69% pregnancy rate with a foaling rate of 83%. These percentages are reduced to 11 and 23%, respectively, for cloned embryos. In conclusion, extensive evidence exists that in vitro matured equine oocytes can efficiently develop into viable embryos and offspring.

Effects of high gravity on amphibian development.

PubMed

Kashiwagi, Akihiko; Hanada, Hideki; Kawakami, Satomi; Kubo, Hideo; Shinkai, Tadashi; Fujii, Hirotada; Kashiwagi, Keiko

2003-10-01

In order to clarify the possible effects of high gravity environments on eggs and developing embryos, Rana rugosa and Xenopus laevis fertilized eggs and early embryos were raised in 2 G, 5 G, 7 G and 10 G up to the hatched tadpole stage. The results showed that: (1) High gravity significantly retarded the development of eggs and embryos beginning treatment before the blastula stage and induced various abnormalities, including two heads and microcephally suggesting that high gravity is apt to disrupt the animal-vegital axis. On the other hand, embryos beginning treatment after the gastrula stage showed a striking increase in the number of normal-appearing feeding tadpoles. (2) Autopsy revealed that brains, notochords and muscles were reduced in development and differentiation for embryos and tadpoles developed in high gravity. (3) It seems likely that the system for hydrogen peroxide detoxification develops abnormally in high gravity-treated embryos and tadpoles, which probably results in oxidative stress, leading to considerable cell damage.

POST-HARVEST EMBRYO DEVELOPMENT IN GINSENG SEEDS INCREASES DESICCATION SENSITIVITY AND NARROWS THE HYDRATION WINDOW FOR CRYOPRESERVATION.

PubMed

Han, E; Popova, E; Cho, G; Park, S; Lee, S; Pritchard, H W; Kim, H H

Despite its self-pollinating characteristics, Korean ginseng germplasm is mainly maintained in clonal gene banks as there is no defined approach to the long-term conservation of its seed, including the most appropriate stage of embryo development for storage. The aim of this study was to reveal the effect of embryo development on desiccation tolerance and cryopreservation success in ginseng seeds. Seeds of Korean ginseng (Panax ginseng C.A. Meyer) at three post-harvest stages (immediately after harvesting and following treatments to enable internal growth of the embryo) were desiccated and cryopreserved. The hydration window for the >80% dehiscence and germination of cryopreserved ginseng seeds varied with embryo developmental stage: 3-9% moisture content (MC) for both unpulped and undehisced seeds when the embryo was 0.1 the length of the endosperm, 7-10% MC for dehisced seeds (0.5 embryo:endosperm) and 9-11% MC for seeds with fully developed embryos (0.9 embryo:endosperm). Whilst dried (4-8% moisture content) and undehisced seeds within fruits (unpulped seeds) lost more than half their viability during 1 year's storage at room temperature, cryopreservation enabled germination levels of c. 90%. Overall, 432 accessions of Korean ginseng landraces have been cryopreserved using undehisced seeds with or without fruits. Post-harvest treatment of Korean ginseng seeds to enable embryo development decreases tolerance of very low MCs, and thus narrows the hydration window for cryopreservation. Fresh-harvested and unpulped seeds that have been dried to c. 5% MC are recommended for long-term cryogenic storage.

Analysis of compaction initiation in human embryos by using time-lapse cinematography.

PubMed

Iwata, Kyoko; Yumoto, Keitaro; Sugishima, Minako; Mizoguchi, Chizuru; Kai, Yoshiteru; Iba, Yumiko; Mio, Yasuyuki

2014-04-01

To analyze the initiation of compaction in human embryos in vitro by using time-lapse cinematography (TLC), with the goal of determining the precise timing of compaction and clarifying the morphological changes underlying the compaction process. One hundred and fifteen embryos donated by couples with no further need for embryo-transfer were used in this study. Donated embryos were thawed and processed, and then their morphological behavior during the initiation of compaction was dynamically observed via time-lapse cinematography (TLC) for 5 days. Although the initiation of compaction occurred throughout the period from the 4-cell to 16-cell stage, 99 (86.1 %) embryos initiated compaction at the 8-cell stage or later, with initiation at the 8-cell stage being most frequent (22.6 %). Of these 99 embryos, 49.5 % developed into good-quality blastocysts. In contrast, of the 16 (13.9 %) embryos that initiated compaction prior to the 8-cell stage, only 18.8 % developed into good-quality blastocysts. Embryos that initiated compaction before the 8-cell stage showed significantly higher numbers of multinucleated blastomeres, due to asynchronism in nuclear division at the third mitotic division resulting from cytokinetic failure. The initiation of compaction primarily occurs at the third mitotic division or later in human embryos. Embryos that initiate compaction before the 8-cell stage are usually associated with aberrant embryonic development (i.e., cytokinetic failure accompanied by karyokinesis).

Enhance beef cattle improvement by embryo biotechnologies.

PubMed

Wu, B; Zan, L

2012-10-01

Embryo biotechnology has become one of the prominent high businesses worldwide. This technology has evolved through three major changes, that is, traditional embryo transfer (in vivo embryo production by donor superovulation), in vitro embryo production by ovum pick up with in vitro fertilization and notably current cloning technique by somatic cell nuclear transfer and transgenic animal production. Embryo biotechnology has widely been used in dairy and beef cattle industry and commercial bovine embryo transfer has become a large international business. Currently, many developed biotechnologies during the period from early oocyte stage to pre-implantation embryos can be used to create new animal breeds and accelerate genetic progression. Based on recent advances in embryo biotechnologies and authors current studies, this review will focus on a description of the application of this technology to beef cattle improvement and discuss how to use this technology to accelerate beef cattle breeding and production. The main topics of this presentation include the following: (i) how to increase calf production numbers from gametes including sperm and oocyte; (ii) multiple ovulation and embryo transfer breeding schemes; (iii) in vitro fertilization and intracytoplasm sperm injection in bovine; (iv) pronuclear development and transgenic animals; (v) sex selection from sperm and embryos; (vi) cloning and androgenesis; (vii) blastocyst development and embryonic stem cells; (viii) preservation of beef cattle genetic resources; and (ix) conclusions. © 2011 Blackwell Verlag GmbH.

Early Activation of MAPK and Apoptosis in Nutritive Embryos of Calyptraeid Gastropods.

PubMed

Lesoway, Maryna P; Collin, Rachel; Abouheif, Ehab

2017-07-01

Investigation of alternative phenotypes, different morphologies produced by a single genome, has contributed novel insights into development and evolution. Yet, the mechanisms underlying developmental switch points between alternative phenotypes remain poorly understood. The calyptraeid snails Crepidula navicella and Calyptraea lichen produce two phenotypes: viable and nutritive embryos, where nutritive embryos arrest their development after gastrulation and are ingested by their viable siblings as a form of intracapsular nutrition. Here, we investigate the activity of mitogen-activated protein kinase (MAPK, ERK1/2) and apoptosis during early cleavage. MAPK and apoptosis, found in a previous transcriptomic study, are known to be involved in organization of other spiralian embryos and nutritive embryo development, respectively. In the model Crepidula fornicata, MAPK activation begins at the 16-cell stage. In contrast, we discovered in C. navicella and C. lichen that many embryos begin MAPK activation at the one-cell stage. A subset of embryos shows a similar pattern of MAPK activation to C. fornicata at later stages. In all stages where MAPK is detected, the activation pattern is highly variable, frequently occurring in all quadrants or in multiple tiers of cells. We also detected apoptosis in cleaving embryos, while C. fornicata and Crepidula lessoni, which do not produce nutritive embryos, show no signs of apoptosis during cleavage. Our results show that MAPK and apoptosis are expressed during early development in species with nutritive embryos, and raises the possibility that these processes may play a role and even interact with one another in producing the nutritive embryo phenotype. © 2017 Wiley Periodicals, Inc.

Expression of renin–angiotensin system components in the early bovine embryo

PubMed Central

Pijacka, Wioletta; Hunter, Morag G; Broughton Pipkin, Fiona; Luck, Martin R

2012-01-01

The renin–angiotensin system (RAS), mainly associated with the regulation of blood pressure, has been recently investigated in female reproductive organs and the developing foetus. Angiotensin II (Ang II) influences oviductal gamete movements and foetal development, but there is no information about RAS in the early embryo. The aim of this study was to determine whether RAS components are present in the pre-implantation embryo, to determine how early they are expressed and to investigate their putative role at this stage of development. Bovine embryos produced in vitro were used for analysis of RAS transcripts (RT-PCR) and localisation of the receptors AGTR1 and AGTR2 (immunofluorescent labelling). We also investigated the effects of Ang II, Olmesartan (AGTR1 antagonist) and PD123319 (AGTR2 antagonist) on oocyte cleavage, embryo expansion and hatching. Pre-implanted embryos possessed AGTR1 and AGTR2 but not the other RAS components. Both receptors were present in the trophectoderm and in the inner cell mass of the blastocyst. AGTR1 was mainly localised in granular-like structures in the cytoplasm, suggesting its internalisation into clathrin-coated vesicles, and AGTR2 was found mainly in the nuclear membrane and in the mitotic spindle of dividing trophoblastic cells. Treating embryos with PD123319 increased the proportion of hatched embryos compared with the control. These results, the first on RAS in the early embryo, suggest that the pre-implanted embryo responds to Ang II from the mother rather than from the embryo itself. This may be a route by which the maternal RAS influences blastocyst hatching and early embryonic development. PMID:23781300

Early embryonic survival and embryo development in two lines of rabbits divergently selected for uterine capacity.

PubMed

Peiró, R; Santacreu, M A; Climent, A; Blasco, A

2007-07-01

The aim of this work is to study early embryo survival and development in 2 lines divergently selected for high and low uterine capacity throughout 10 generations. A total of 162 female rabbits from the high line and 133 from the low line were slaughtered at 25, 48, or 62 h of gestation. There were no differences in ovulation rate and fertilization rate between lines in any of the 3 stages of gestation. Embryo survival, estimated as the number of normal embryos recovered at a constant ovulation rate, was similar in both lines at 25 and 48 h. Embryo survival was greater in the high line [D (posterior mean of the difference between the high and low lines) = 0.57 embryos] at 62 h of gestation. There was no difference in embryonic stage of development at 25 h, but at 48 and 62 h of gestation, the high line, compared with the low line, had a greater percentage of early morulae (83 vs. 72%) and compacted morulae (55 vs. 38%). Divergent selection for uterine capacity appeared to modify embryo development, at least from 48 h of gestation, and embryo survival from 62 h.

Latrunculin A treatment prevents abnormal chromosome segregation for successful development of cloned embryos.

PubMed

Terashita, Yukari; Yamagata, Kazuo; Tokoro, Mikiko; Itoi, Fumiaki; Wakayama, Sayaka; Li, Chong; Sato, Eimei; Tanemura, Kentaro; Wakayama, Teruhiko

2013-01-01

Somatic cell nuclear transfer to an enucleated oocyte is used for reprogramming somatic cells with the aim of achieving totipotency, but most cloned embryos die in the uterus after transfer. While modifying epigenetic states of cloned embryos can improve their development, the production rate of cloned embryos can also be enhanced by changing other factors. It has already been shown that abnormal chromosome segregation (ACS) is a major cause of the developmental failure of cloned embryos and that Latrunculin A (LatA), an actin polymerization inhibitor, improves F-actin formation and birth rate of cloned embryos. Since F-actin is important for chromosome congression in embryos, here we examined the relation between ACS and F-actin in cloned embryos. Using LatA treatment, the occurrence of ACS decreased significantly whereas cloned embryo-specific epigenetic abnormalities such as dimethylation of histone H3 at lysine 9 (H3K9me2) could not be corrected. In contrast, when H3K9me2 was normalized using the G9a histone methyltransferase inhibitor BIX-01294, the Magea2 gene-essential for normal development but never before expressed in cloned embryos-was expressed. However, this did not increase the cloning success rate. Thus, non-epigenetic factors also play an important role in determining the efficiency of mouse cloning.

Nucleoli from two-cell embryos support the development of enucleolated germinal vesicle oocytes in the pig.

PubMed

Kyogoku, Hirohisa; Ogushi, Sugako; Miyano, Takashi

2012-11-01

Recent research has shown that nucleoli of oocytes at the germinal vesicle (GV) stage (GV nucleoli) are not necessary for oocyte maturation but are essential for early embryonic development. Nucleoli of 2-cell embryos (2-cell nucleoli) have morphology similar to that of nucleoli in oocytes at the GV stage. In this study, we examined the ability of 2-cell nucleoli to substitute for GV nucleoli in terms of supporting early embryonic development by nucleolus aspiration (enucleolation) and transfer into metaphase II (MII) oocytes or 2-cell embryos that were derived from enucleolated oocytes at the GV stage in the pig. When 2-cell embryos were centrifuged to move the lipid droplets to one side of the blastomere, multiple nucleoli in the nucleus fused into a single nucleolus. The nucleoli were then aspirated from the 2-cell embryos by micromanipulation. The injection of 2-cell nucleoli to GV enucleolated oocytes at the MII stage rescued the embryos from the early embryonic arrest, and the resulting oocytes developed to blastocysts. However, the injection of 2-cell and GV nucleoli to 2-cell embryos derived from GV enucleolated oocytes rarely restored the development to blastocysts. These results indicate that 2-cell nucleoli support early embryonic development as GV nucleoli and that the presence of nucleoli is essential for pig embryos before the 2-cell stage.

Characterizing early embryonic development of Brown Tsaiya Ducks (Anas platyrhynchos) in comparison with Taiwan Country Chicken (Gallus gallus domestics)

PubMed Central

Lumsangkul, Chompunut; Fan, Yang-Kwang; Chang, Shen-Chang; Ju, Jyh-Cherng

2018-01-01

Avian embryos are among the most convenient and the primary representatives for the study of classical embryology. It is well-known that the hatching time of duck embryos is approximately one week longer than that of chicken embryos. However, the key features associated with the slower embryonic development in ducks have not been adequately described. This study aimed to characterize the pattern and the speed of early embryogenesis in Brown Tsaiya Ducks (BTD) compared with those in Taiwan Country Chicken (TCC) by using growth parameters including embryonic crown-tail length (ECTL), primitive streak formation, somitogenesis, and other development-related parameters, during the first 72 h of incubation. Three hundred and sixty eggs from BTD and TCC, respectively, were incubated at 37.2°C, and were then dissected hourly to evaluate their developmental stages. We found that morphological changes of TCC embryos shared a major similarity with that of the Hamburger and Hamilton staging system during early chick embryogenesis. The initial primitive streak in TCC emerged between 6 and 7 h post-incubation, but its emergence was delayed until 10 to 13 h post-incubation in BTD. Similarly, the limb primordia (wing and limb buds) were observed at 51 h post-incubation in TCC embryos compared to 64 h post-incubation in BTD embryos. The allantois first appeared around 65 to 68 h in TCC embryos, but it was not observed in BTD embryos. At the 72 h post-incubation, 40 somites were clearly formed in TCC embryos while only 32 somites in BTD embryos. Overall, the BTD embryos developed approximately 16 h slower than the chicken embryo during the first 72 h of development. To our best knowledge, this is the first study to describe two distinct developmental time courses between TCC and BTD, which would facilitate future embryogenesis-related studies of the two important avian species in Taiwan. PMID:29742160

[TSA improve transgenic porcine cloned embryo development and transgene expression].

PubMed

Kong, Qing-Ran; Zhu, Jiang; Huang, Bo; Huan, Yan-Jun; Wang, Feng; Shi, Yong-Qian; Liu, Zhong-Feng; Wu, Mei-Ling; Liu, Zhong-Hua

2011-07-01

Uncompleted epigenetic reprogramming is attributed to the low efficiency of producing transgenic cloned animals. Histone modification associated with epigenetics can directly influence the embryo development and transgene expression. Trichostatin A (TSA), as an inhibitor of histone deacetylase, can change the status of histone acetylation, improve somatic cell reprogramming, and enhance cloning efficiency. TSA prevents the chromatin structure from being condensed, so that transcription factor could binds to DNA sequence easily and enhance transgene expression. Our study established the optimal TSA treatment on porcine donor cells and cloned embryos, 250 nmol/L, 24 h and 40 nmol/L, 24 h, respectively. Furthermore, we found that both the cloned embryo and the donor cell treated by TSA resulted in the highest development efficiency. Meanwhile, TSA can improve transgene expression in donor cell and cloned embryo. In summary, TSA can significantly improve porcine reconstructed embryo development and transgene expression.

Research Methods to Develop Measures of Effectiveness of the United States Coast Guard’s Vessel Inspection and Boarding Program. Decision Support for Utilizing Measures of Effectiveness - Volume III

DTIC Science & Technology

1995-05-01

Eubank S.E. Albuquerque, NM 87123 Christopher Rodriguez Kevin Downer U.S. Coast Guard Research and Development Center 1082 Shennecossett Road Groton...standard, specifica )e n. ’OVVELOPj4 Commanding Officer United States Coast Guard Research & Development Center 1082 Shennecossett Road SGroton, CT...Work Unit No. (TRAIS) U.S. Coast Guard Sandia National Laboratories Research and Development Center 11. Contract or Grant No. 1515 Eubank SE 1082

Viability and DNA fragmentation of rainbow trout embryos (Oncorhynchus mykiss) obtained from eggs stored at 4 °C.

PubMed

Ubilla, A; Valdebenito, I; Árias, M E; Risopatrón, J

2016-05-01

In vitro storage of salmonid eggs leads to aging of the cells causing a decline in quality and reducing their capacity to develop and produce embryos. The quality of salmonid embryos is assessed by morphologic analyses; however, data on the application of biomarkers to determine the cell viability and DNA integrity of embryos in these species are limited. The aim of this study was to evaluate the effect on embryo development, viability and DNA fragmentation in the embryonic cells of in vitro storage time at 4 °C of rainbow trout (Oncorhynchus mykiss) eggs. The embryos were obtained by IVF from eggs stored for 0 (control), 48, and 96 hours at 4 °C. At 72 hours after fertilization, dechorionated embryos were examined to determine percentages of developed embryos (embryos with normal cell division morphology), viability (LIVE/DEAD sperm viability kit), and DNA integrity (terminal deoxynucleotidyl transferase [TdT] dUTP nick-end labeling assay). The percentage of developing embryos decreased (P < 0.05) with storage time of the eggs (95.10 ± 2.55; 88.14 ± 4.50; 79.99 ± 6.60 for 0, 48, and 96 hours, respectively). Similarly, cell viability decreased (P < 0.05; 96.07 ± 7.15; 80.42 ± 8.55; 77.47 ± 7.88 for 0, 48, and 96 hours, respectively), and an increase (P < 0.05) in DNA fragmentation in the embryos was observed at 96-hour storage. A positive correlation was found between cell DNA fragmentation and storage time (r = 0.8173; P < 0.0001). The results revealed that terminal deoxynucleotidyl transferase [TdT] dUTP nick-end labeling assay technique is reliable mean to assess the state of the DNA in salmonid embryos and that in vitro eggs storage for 96h reduces embryo development and cell DNA integrity. DNA integrity evaluation constitutes a biomarker of the quality of the ova and resulting embryos so as to predict their capacity to produce good-quality embryos in salmonids, particularly under culture conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Release of somatic embryogenic potential from excised zygotic embryos of carrot and maintenance of proembryonic cultures in hormone-free medium.

PubMed

Smith, D L; Krikorian, A D

1989-01-01

Excised zygotic embryos, mericarps ("seeds") and hypocotyls of seedlings of cultivated carrot Daucus carota cv. Scarlet Nantes were evaluated for their ability to generate somatic embryos on a semisolid hormone-free nutrient medium. Neither intact zygotic embryos nor hypocotyls ever produced somatic embryos. However, mericarps and broken zygotic embryos were excellent sources for somatic embryo production (response levels as high as 86%). Somatic embryo formation was highest from cotyledons, but was also observed on isolated hypocotyls and root tips of mature zygotic embryos. On media containing unreduced nitrogen, somatic embryo formation led to the generation of vigorous cultures comprised entirely of somatic embryos at various stages of development which in turn proliferated still other somatic embryos. However, a medium was devised which when 1-5 mM NH4+ was the sole nitrogen source, led only to a proliferation of globular proembryos. Sustained subculturing of these proembryos at 2-3 week intervals enabled establishment of highly uniform cultures in which no further development into more mature stages of embryonic development occurred. These have been maintained, without decline, as morphogenetically competent proembryonic globules for over ten months. A basal medium containing from 1-5 mM NH4+ as the sole nitrogen source appears not to be inductive to somatic proembryo formation. Instead, such a medium is best thought of as permissive to the expression of embryogenically determined cells within zygotic embryos. By excising and breaking or wounding zygotic embryos, constituent cells are probably released from positional or chemical restraints and thus are able to express their innate embryogenic potential. Once a proembryonic culture is established, this medium containing 1-5 mM NH4+ as the sole nitrogen source provides a nonpermissive environment to the development and growth of later embryonic stages, but it does allow the continued formation and multiplication of globular somatic proembryos. The sequence of events leading from excised broken zygotic embryos to the formation of somatic embryos and the maintenance of somatic proembryos are demonstrated by scanning electron microscopy and histological preparations. Germination levels from intact zygotic embryos on media with varying levels and ratios of unreduced vs. reduced inorganic nitrogen were determined as well and provided baseline or control data on the type of response obtained from nonwounded material.

Release of somatic embryogenic potential from excised zygotic embryos of carrot and maintenance of proembryonic cultures in hormone-free medium

NASA Technical Reports Server (NTRS)

Smith, D. L.; Krikorian, A. D.

1989-01-01

Excised zygotic embryos, mericarps ("seeds") and hypocotyls of seedlings of cultivated carrot Daucus carota cv. Scarlet Nantes were evaluated for their ability to generate somatic embryos on a semisolid hormone-free nutrient medium. Neither intact zygotic embryos nor hypocotyls ever produced somatic embryos. However, mericarps and broken zygotic embryos were excellent sources for somatic embryo production (response levels as high as 86%). Somatic embryo formation was highest from cotyledons, but was also observed on isolated hypocotyls and root tips of mature zygotic embryos. On media containing unreduced nitrogen, somatic embryo formation led to the generation of vigorous cultures comprised entirely of somatic embryos at various stages of development which in turn proliferated still other somatic embryos. However, a medium was devised which when 1-5 mM NH4+ was the sole nitrogen source, led only to a proliferation of globular proembryos. Sustained subculturing of these proembryos at 2-3 week intervals enabled establishment of highly uniform cultures in which no further development into more mature stages of embryonic development occurred. These have been maintained, without decline, as morphogenetically competent proembryonic globules for over ten months. A basal medium containing from 1-5 mM NH4+ as the sole nitrogen source appears not to be inductive to somatic proembryo formation. Instead, such a medium is best thought of as permissive to the expression of embryogenically determined cells within zygotic embryos. By excising and breaking or wounding zygotic embryos, constituent cells are probably released from positional or chemical restraints and thus are able to express their innate embryogenic potential. Once a proembryonic culture is established, this medium containing 1-5 mM NH4+ as the sole nitrogen source provides a nonpermissive environment to the development and growth of later embryonic stages, but it does allow the continued formation and multiplication of globular somatic proembryos. The sequence of events leading from excised broken zygotic embryos to the formation of somatic embryos and the maintenance of somatic proembryos are demonstrated by scanning electron microscopy and histological preparations. Germination levels from intact zygotic embryos on media with varying levels and ratios of unreduced vs. reduced inorganic nitrogen were determined as well and provided baseline or control data on the type of response obtained from nonwounded material.

Manipulating the Mitochondrial Genome To Enhance Cattle Embryo Development

PubMed Central

Srirattana, Kanokwan; St. John, Justin C.

2017-01-01

The mixing of mitochondrial DNA (mtDNA) from the donor cell and the recipient oocyte in embryos and offspring derived from somatic cell nuclear transfer (SCNT) compromises genetic integrity and affects embryo development. We set out to generate SCNT embryos that inherited their mtDNA from the recipient oocyte only, as is the case following natural conception. While SCNT blastocysts produced from Holstein (Bos taurus) fibroblasts were depleted of their mtDNA, and oocytes derived from Angus (Bos taurus) cattle possessed oocyte mtDNA only, the coexistence of donor cell and oocyte mtDNA resulted in blastocysts derived from nondepleted cells. Moreover, the use of the reprogramming agent, Trichostatin A (TSA), further improved the development of embryos derived from depleted cells. RNA-seq analysis highlighted 35 differentially expressed genes from the comparison between blastocysts generated from nondepleted cells and blastocysts from depleted cells, both in the presence of TSA. The only differences between these two sets of embryos were the presence of donor cell mtDNA, and a significantly higher mtDNA copy number for embryos derived from nondepleted cells. Furthermore, the use of TSA on embryos derived from depleted cells positively modulated the expression of CLDN8, TMEM38A, and FREM1, which affect embryonic development. In conclusion, SCNT embryos produced by mtDNA depleted donor cells have the same potential to develop to the blastocyst stage without the presumed damaging effect resulting from the mixture of donor and recipient mtDNA. PMID:28500053

Early Embryo Development in Fucus distichus Is Auxin Sensitive1

PubMed Central

Basu, Swati; Sun, Haiguo; Brian, Leigh; Quatrano, Ralph L.; Muday, Gloria K.

2002-01-01

Auxin and polar auxin transport have been implicated in controlling embryo development in land plants. The goal of these studies was to determine if auxin and auxin transport are also important during the earliest stages of development in embryos of the brown alga Fucus distichus. Indole-3-acetic acid (IAA) was identified in F. distichus embryos and mature tissues by gas chromatography-mass spectroscopy. F. distichus embryos accumulate [3H]IAA and an inhibitor of IAA efflux, naphthylphthalamic acid (NPA), elevates IAA accumulation, suggesting the presence of an auxin efflux protein complex similar to that found in land plants. F. distichus embryos normally develop with a single unbranched rhizoid, but growth on IAA leads to formation of multiple rhizoids and growth on NPA leads to formation of embryos with branched rhizoids, at concentrations that are active in auxin accumulation assays. The effects of IAA and NPA are complete before 6 h after fertilization (AF), which is before rhizoid germination and cell division. The maximal effects of IAA and NPA are between 3.5 and 5 h AF and 4 and 5.5 h AF, respectively. Although, the location of the planes of cell division was significantly altered in NPA- and IAA-treated embryos, these abnormal divisions occurred after abnormal rhizoid initiation and branching was observed. The results of this study suggest that auxin acts in the formation of apical basal patterns in F. distichus embryo development. PMID:12226509

Cinematographic analysis of bovine embryo development in serum-free oviduct-conditioned medium.

PubMed

Grisart, B; Massip, A; Dessy, F

1994-07-01

Development of bovine embryos produced in vitro from the one-cell to the blastocyst stage in serum-free oviduct-conditioned medium was investigated for 8 days consecutively by time-lapse cinematography. Three movies were analysed (130 embryos). The following observations were made. (1) Development under cine-recording conditions was similar to that in a classical incubator. (2) The highest proportion of embryos at the two-cell, three-four-cell, five-eight-cell, 9-16-cell, morula and blastocyst stages were recorded at 34, 46, 61, 115, 149 and 192 h after insemination, respectively. Cleavage asynchrony between blastomeres within individual embryos started at the two-cell stage. (3) The duration of the first three cell cycles was 35 h, 14 h and 11-62 h, respectively. (4) Detailed analysis of 13 embryos revealed that developmental arrest ('Lag-phase') occurred at the four-cell (1 of 13), five-cell (2 of 13), six-cell (3 of 13), seven-cell (3 of 13) or eight-cell stage (4 of 13); this phase lasted about 59 h. Embryos arrested at the eight-cell stage developed into morula-blastocysts (3 of 4) at a higher rate than did those arrested at earlier stages (2 of 9). (5) The faster the embryos cleaved into early stages (two-cell, three-four-cell and five-eight-cell), the higher the probability that they developed into morula-blastocyst: 70% of the embryos reaching the two-cell stage before 30-31 h after insemination developed into morula-blastocyst.(ABSTRACT TRUNCATED AT 250 WORDS)

Embryotoxic cytokines-Potential roles in embryo loss and fetal programming.

PubMed

Robertson, Sarah A; Chin, Peck-Yin; Femia, Joseph G; Brown, Hannah M

2018-02-01

Cytokines in the reproductive tract environment at conception mediate a dialogue between the embryo and maternal tissues to profoundly influence embryo development and implantation success. Through effects on gene expression and the cell stress response, cytokines elicit an epigenetic impact with consequences for placental development and fetal growth, which in turn affect metabolic phenotype and long-term health of offspring. There is substantial evidence demonstrating that pro-survival cytokines, such as GM-CSF, CSF1, LIF, HB-EGF and IGFII, support embryos to develop optimally. Less attention has been paid to cytokines that adversely impact embryo development, including the pro-inflammatory cytokines TNF, TRAIL and IFNG. These agents elicit cell stress, impair cell survival and retard blastocyst development, and at sufficiently high concentrations, can cause embryo demise. Experiments in mice suggest these so-called 'embryotoxic' cytokines can harm embryos through pro-apoptotic and adverse programming effects, as well as indirectly suppressing uterine receptivity through the maternal immune response. Embryotrophic factors may mitigate against and protect from these adverse effects. Thus, the balance between embryotrophic and embryotoxic cytokines can impart effects on embryo development and implantation, and has the potential to contribute to endometrial 'biosensor' function to mediate embryo selection. Embryotoxic cytokines can be elevated in plasma and reproductive tract tissues in inflammatory conditions including infection, diabetes, obesity, PCOS and endometriosis. Studies are therefore warranted to investigate whether excessive embryotoxic cytokines contribute to infertility and recurrent implantation failure in women, and compromised reproductive performance in livestock animals. Copyright © 2018 Elsevier B.V. All rights reserved.

Using game theory to investigate the epigenetic control mechanisms of embryo development. Comment on: ;Epigenetic game theory: How to compute the epigenetic control of maternal-to-zygotic transition; by Qian Wang et al.

NASA Astrophysics Data System (ADS)

Zhang, Le; Zhang, Shaoxiang

2017-03-01

A body of research [1-7] has already shown that epigenetic reprogramming plays a critical role in maintaining the normal development of embryos. However, the mechanistic quantitation of the epigenetic interactions between sperms and oocytes and the related impact on embryo development are still not clear [6,7]. In this study, Wang et al., [8] develop a modeling framework that addresses this question by integrating game theory and the latest discoveries of the epigenetic control of embryo development.

Incubation media affect the survival, pathway and time of embryo development in Neotropical annual fish Austrolebias nigrofasciatus (Rivulidae).

PubMed

da Fonseca, A P; Volcan, M V; Robaldo, R B

2018-01-01

To analyse the survival, pathway and time of embryo development in the annual fish Austrolebias nigrofasciatus eggs were monitored in four liquid media and two damp media under experimental conditions for 130 days until their development was complete. Eggs kept in the same breeding water from oviposition remained in diapause I (DI) during all experiments. In constrast, up to the stage prior to entering diapause II (DII), the other media had no influence on development. Embryos at this stage (DII), however, show longer development time when treated in medium with water and powdered coconut shell so that about 80% of embryos remained in DII at 100 days. In contrast, all other treatments had a significantly lower proportion of embryos remaining in DII. When treated with Yamamoto's solution in humid media, embryos showed the fastest development. The first fully developed embryos (DIII) were seen at 27 days after oviposition. It took an average of 46-58 days for 50% of eggs in each treatment to reach DIII. Compared with other studies, survival in all incubation media was high at between 70 and 98%. Taken together, it can be concluded that all incubation media were found to be viable for maintaining embryos. Altering developmental trajectories through the manipulation of diapauses in different media makes this species a potential model organism for laboratory studies. © 2017 The Fisheries Society of the British Isles.

Synthetic profiles of polypeptides of human oocytes and normal and abnormal preimplantation embryos.

PubMed

Capmany, G; Bolton, V N

1999-09-01

There is considerable variation in the rate of development in vitro of individual preimplantation human embryos. The relationship between the rate of development and patterns of polypeptide synthesis in individual embryos was examined using SDS-PAGE and autoradiography. After incubation in [35S]methionine, 19 polypeptide bands were identified that change between fertilization and the morula stage. Although changes in two of the bands occurred in embryos that were developing normally and in ageing oocytes, and are thus independent of fertilization, the changes identified in the remaining 17 bands occurred only after fertilization. In embryos that were developing abnormally, as assessed by delayed cleavage, cleavage arrest or extensive fragmentation, the alteration in polypeptide synthetic profiles increased with increasing abnormality.

Expression of microRNAs in bovine and human pre-implantation embryo culture media

PubMed Central

Kropp, Jenna; Salih, Sana M.; Khatib, Hasan

2014-01-01

MicroRNAs (miRNA) are short non-coding RNAs which act to regulate expression of genes driving numerous cellular processes. These RNAs are secreted within exosomes from cells into the extracellular environment where they may act as signaling molecules. In addition, they are relatively stable and are specifically expressed in association to certain cancers making them strong candidates as biological markers. Moreover, miRNAs have been detected in body fluids including urine, milk, saliva, semen, and blood plasma. However, it is unknown whether they are secreted by embryonic cells into the culture media. Given that miRNAs are expressed throughout embryonic cellular divisions and embryonic genome activation, we hypothesized that they are secreted from the embryo into the extracellular environment and may play a role in the developmental competence of bovine embryos. To test this hypothesis, bovine embryos were cultured individually from day 5 to day 8 of development in an in vitro fertilization system and gene expression of 5 miRNAs was analyzed in both embryos and culture media. Differential miRNA gene expression was observed between embryos that developed to the blastocyst stage and those that failed to develop from the morula to blastocyst stage, deemed degenerate embryos. MiR-25, miR-302c, miR-196a2, and miR-181a expression was found to be higher in degenerate embryos compared to blastocyst embryos. Interestingly, these miRNAs were also found to be expressed in the culture media of both bovine and human pre-implantation embryos. Overall, our results show for the first time that miRNAs are secreted from pre-implantation embryos into culture media and that miRNA expression may correlate with developmental competence of the embryo. Expression of miRNAs in in vitro culture media could allow for the development of biological markers for selection of better quality embryos and for subsequent successful pregnancy. PMID:24795753

A Cascade of Sequentially Expressed Sucrose Transporters in the Seed Coat and Endosperm Provides Nutrition for the Arabidopsis Embryo[OPEN

PubMed Central

Chen, Li-Qing; Lin, I Winnie; Qu, Xiao-Qing; Sosso, Davide; McFarlane, Heather E.; Londoño, Alejandra; Samuels, A. Lacey; Frommer, Wolf B.

2015-01-01

Developing plant embryos depend on nutrition from maternal tissues via the seed coat and endosperm, but the mechanisms that supply nutrients to plant embryos have remained elusive. Sucrose, the major transport form of carbohydrate in plants, is delivered via the phloem to the maternal seed coat and then secreted from the seed coat to feed the embryo. Here, we show that seed filling in Arabidopsis thaliana requires the three sucrose transporters SWEET11, 12, and 15. SWEET11, 12, and 15 exhibit specific spatiotemporal expression patterns in developing seeds, but only a sweet11;12;15 triple mutant showed severe seed defects, which include retarded embryo development, reduced seed weight, and reduced starch and lipid content, causing a “wrinkled” seed phenotype. In sweet11;12;15 triple mutants, starch accumulated in the seed coat but not the embryo, implicating SWEET-mediated sucrose efflux in the transfer of sugars from seed coat to embryo. This cascade of sequentially expressed SWEETs provides the feeding pathway for the plant embryo, an important feature for yield potential. PMID:25794936

Prognostic factors for patients undergoing vitrified-warmed human embryo transfer cycles: a retrospective cohort study.

PubMed

Takahashi, Toshifumi; Hasegawa, Ayumi; Igarashi, Hideki; Amita, Mitsuyoshi; Matsukawa, Jun; Takehara, Isao; Suzuki, Satoko; Nagase, Satoru

2017-06-01

We examined the prognostic factors for pregnancy in 210 vitrified-warmed embryo transfer (ET) cycles in 121 patients. The univariate analysis showed that age, gravida, the number of cycles associated with infertility caused by endometriosis, the number of previous assisted reproductive technology (ART) treatment cycles, and the number of ICSI procedures were significantly lower in pregnant cycles compared with non-pregnant cycles. The percentages of ET using at least one intact embryo and of ET using at least one embryo that had developed further after warming were significantly higher in pregnant cycles compared with non-pregnant cycles. Multivariate logistic regression analysis showed that previous ART treatment cycles, ET with at least one intact embryo, and ET using at least one embryo that had developed further were independent prognostic factors for pregnancy in vitrified-warmed ET cycles. We conclude that fewer previous ART treatment cycles, ET using at least one intact embryo, and ET with embryos that have developed further after warming might be favourable prognostic factors for pregnancy in vitrified-warmed ET cycles.

Influence of cell loss after vitrification or slow-freezing on further in vitro development and implantation of human Day 3 embryos.

PubMed

Van Landuyt, L; Van de Velde, H; De Vos, A; Haentjens, P; Blockeel, C; Tournaye, H; Verheyen, G

2013-11-01

Is the effect of cell loss on further cleavage and implantation different for vitrified than for slowly frozen Day 3 embryos? Vitrified embryos develop better overnight than slowly frozen embryos, regardless of the number of cells lost, but have similar implantation potential if further cleavage occurs overnight. After slow-freezing, similar implantation rates have been obtained for intact 4-cell embryos or 4-cell embryos with 1 cell damaged. For slowly frozen Day 3 embryos, lower implantation rates have been observed when at least 25% of cells were lost. Other studies reported similar implantation potential for 7- to 8-cell embryos with 0, 1 or 2 cells damaged. No data are available on further development of vitrified embryos in relation to cell damage. Survival and overnight cleavage were retrospectively assessed for 7664 slowly frozen Day 3 embryos (study period: January 2004-December 2008) and 1827 vitrified embryos (study period: April 2010-September 2011). Overnight cleavage was assessed according to cell stage at cryopreservation and post-thaw cell loss for both protocols. The relationship between cell loss and implantation rate was analysed in a subgroup of single-embryo transfers (SETs) with 780 slowly frozen and 294 vitrified embryos. Embryos with ≥6 blastomeres and ≤20% fragmentation were cryopreserved using slow controlled freezing [with dimethyl sulphoxide (DMSO) as cryoprotectant] or closed vitrification [with DMSO-ethylene glycol (EG)-sucrose (S) as cryoprotectants]. Only embryos with ≥50% of cells intact after thawing were cultured overnight and were only transferred if further cleaved. For each outcome, logistic regression analysis was performed. Survival was 94 and 64% after vitrification and slow-freezing respectively. Logistic regression analysis showed that overnight cleavage of surviving embryos was higher after vitrification than after slow-freezing (P < 0.001) and decreased according to the degree of cell damage (P < 0.001). If the embryo continued to cleave after thawing, there was no effect of the number of cells lost or the cryopreservation method on its implantation potential. The implantation rates of embryos with 0, 1 or 2 cells damaged were, respectively, 21% (n = 114), 21% (n = 28) and 20% (n = 12) after slow-freezing and 20% (n = 50), 21% (n = 5) and 27% (n = 4) after vitrification. This analysis is retrospective and study periods for vitrification and slow-freezing are different. The number of SETs with vitrified embryos is limited. However, a large number of vitrified embryos were available to analyse the further cleavage of surviving embryos. Although it is not proved that vitrified embryos are more viable than slowly frozen embryos in terms of pregnancy outcome, vitrification yields higher survival rates, better overnight development and higher transfer rates per embryo warmed. This increases the number of frozen transfer cycles originating from a single treatment and might result in a better cumulative clinical outcome. Based on the present data, the policy to warm an extra embryo before overnight culture depends on the cell stage at cryopreservation and the cell damage after warming. For 8-cell embryos, up to two cells may be damaged compared with only one cell for 6- to 7-cell embryos, before an additional embryo is warmed. none.

Comparison of effects of albendazole sulfoxide on in vitro produced bovine embryos and rat embryos.

PubMed

Piscopo, S E; Smoak, I W

1997-09-01

To evaluate and compare effects of albendazole sulfoxide (ABZSO) on rat embryos and bovine embryos produced in vitro. In vitro produced bovine embryos. Rat embryos recovered from naturally bred Sprague-Dawley rats. 4- and 8-cell bovine embryos were randomly allocated to ABZSO or vehicle control groups. After 48 hours, embryos were evaluated for cell number and blastomere morphology. Rat embryos of similar stages, flushed from the uterine tube on gestational day 2-5, were randomly allocated to treatment or control groups. After 24 hours, embryos were evaluated as described previously. 44% of control bovine embryos divided in culture (> or = 16-cell stage). Fifteen percent of the controls had morphologic abnormalities, including disparity in blastomere size and cytoplasmic vacuoles and stippling. Treated (> or = 1 microgram of ABZSO/ml) bovine embryos differed (P < 0.0001) from controls, with 4% development and 93% abnormal morphology. Forty-five percent of control rat embryos divided in culture. Treated (> or = 500 ng of ABZSO/ml) rat embryos differed (P < 0.0003) from controls with regard to ability to divide. There were no consistent morphologic abnormalities in rat embryos. In vitro produced bovine embryos were susceptible to ABZSO at a concentration > or = 1 microgram/ ml, resulting in decreased ability to divide and presence of gross morphologic abnormalities. Rat embryos produced in vivo and exposed in vitro to ABZSO at a concentration > or = 500 ng/ml had decreased ability to divide in culture. Despite severe effects of ABZSO (> or = 1 microgram/ml) on bovine embryo development in vitro, it is beyond the scope of this study to speculate whether a therapeutic dosage of albendazole (10 mg/kg of body weight) would result in necessary concentrations of ABZSO in vivo to disrupt embryogenesis.

Quantifying Three-Dimensional Morphology and RNA from Individual Embryos

PubMed Central

Green, Rebecca M.; Leach, Courtney L.; Hoehn, Natasha; Marcucio, Ralph S.; Hallgrímsson, Benedikt

2017-01-01

Quantitative analysis of morphogenesis aids our understanding of developmental processes by providing a method to link changes in shape with cellular and molecular processes. Over the last decade many methods have been developed for 3D imaging of embryos using microCT scanning to quantify the shape of embryos during development. These methods generally involve a powerful, cross-linking fixative such as paraformaldehyde to limit shrinkage during the CT scan. However, the extended time frames that these embryos are incubated in such fixatives prevent use of the tissues for molecular analysis after microCT scanning. This is a significant problem because it limits the ability to correlate variation in molecular data with morphology at the level of individual embryos. Here, we outline a novel method that allows RNA, DNA or protein isolation following CT scan while also allowing imaging of different tissue layers within the developing embryo. We show shape differences early in craniofacial development (E11.5) between common mouse genetic backgrounds, and demonstrate that we are able to generate RNA from these embryos after CT scanning that is suitable for downstream RT-PCR and RNAseq analyses. PMID:28152580

Intrauterine air impairs embryonic postimplantation development in mice.

PubMed

Liu, Ruonan; Li, Yimeng; Miao, Yanping; Wei, Yanhui; Guan, Mo; Zhou, Rongyan; Li, Xiangyun

2017-12-01

Although most embryologists load air bubbles into the catheter along with embryos during embryo transfer, the effects of these air bubbles on embryo transfer success rate are not clear. Air bubbles were nonsurgically injected into unilateral uterine horns of mice to demonstrate the negative effects of intrauterine air bubbles on embryonic development. Our data showed that when air bubbles are nonsurgically injected into unilateral uterine horns of pregnant 4days mice the litter size is significantly decreased. Four days after the introduction of air, abnormal decidua and dead conceptuses were detected in the uterine horns receiving the air bubbles. In addition, intrauterine air also significantly impaired murine embryo transfer success rates, and induced an increase in endometrial capillary permeability and decidualization in mice on day 4 of pseudopregnancy. These results strongly indicated that the air bubbles loaded into embryo transfer catheters to bracket the embryo-containing medium may have negative effect on embryonic implantation and development. Intrauterine air impaired murine embryonic postimplantation development, and this provided some clues for improving embryo transfer techniques in human. Copyright © 2017 Elsevier B.V. All rights reserved.

Efficient harvesting methods for early-stage snake and turtle embryos.

PubMed

Matsubara, Yoshiyuki; Kuroiwa, Atsushi; Suzuki, Takayuki

2016-04-01

Reptile development is an intriguing research target for understating the unique morphogenesis of reptiles as well as the evolution of vertebrates. However, there are numerous difficulties associated with studying development in reptiles. The number of available reptile eggs is usually quite limited. In addition, the reptile embryo is tightly adhered to the eggshell, making it a challenge to isolate reptile embryos intact. Furthermore, there have been few reports describing efficient procedures for isolating intact embryos especially prior to pharyngula stage. Thus, the aim of this review is to present efficient procedures for obtaining early-stage reptilian embryos intact. We first describe the method for isolating early-stage embryos of the Japanese striped snake. This is the first detailed method for obtaining embryos prior to oviposition in oviparous snake species. Second, we describe an efficient strategy for isolating early-stage embryos of the soft-shelled turtle. © 2016 Japanese Society of Developmental Biologists.

Elucidating the origin of chromosomal aberrations in IVF embryos by preimplantation genetic analysis.

PubMed

Frumkin, Tsvia; Malcov, Mira; Yaron, Yuval; Ben-Yosef, Dalit

2008-01-30

Preimplantation genetic screening (PGS) has been proposed as a method for improving success rates in patients with repeated IVF failures. This approach is based on the hypothesis that such failures are the result of aneuploid embryos. It has been suggested that FISH analysis of blastomeres removed from preimplantation embryos represent the chromosomal constitution of the entire embryo. However, it is not yet clear whether it also represents the chromosomal constitution of the implanted embryo. PGS reanalysis on day 5 of embryos designated as "aneuploid" on day 3 may demonstrate a high rate of mosaicism for chromosomal aberration. Some of these mosaic embryos are capable of developing into normal embryos by "self-correction". Others, however, may accumulate additional chromosomal anomalies. It is therefore concluded that the chromosomal constitution of a preimplantation embryo may evolve during early cleavages. Meiotic and post zygotic mitotic errors may account for these chromosomal aberrations. This review will focus on elucidating the origin of chromosomal changes during preimplantation embryo development by studying their chromosomal constitution at different stages.

Fluorescence-based visualization of autophagic activity predicts mouse embryo viability

NASA Astrophysics Data System (ADS)

Tsukamoto, Satoshi; Hara, Taichi; Yamamoto, Atsushi; Kito, Seiji; Minami, Naojiro; Kubota, Toshiro; Sato, Ken; Kokubo, Toshiaki

2014-03-01

Embryo quality is a critical parameter in assisted reproductive technologies. Although embryo quality can be evaluated morphologically, embryo morphology does not correlate perfectly with embryo viability. To improve this, it is important to understand which molecular mechanisms are involved in embryo quality control. Autophagy is an evolutionarily conserved catabolic process in which cytoplasmic materials sequestered by autophagosomes are degraded in lysosomes. We previously demonstrated that autophagy is highly activated after fertilization and is essential for further embryonic development. Here, we developed a simple fluorescence-based method for visualizing autophagic activity in live mouse embryos. Our method is based on imaging of the fluorescence intensity of GFP-LC3, a versatile marker for autophagy, which is microinjected into the embryos. Using this method, we show that embryonic autophagic activity declines with advancing maternal age, probably due to a decline in the activity of lysosomal hydrolases. We also demonstrate that embryonic autophagic activity is associated with the developmental viability of the embryo. Our results suggest that embryonic autophagic activity can be utilized as a novel indicator of embryo quality.

Simple and efficient production of embryonic stem cell-embryo chimeras by coculture.

PubMed Central

Wood, S A; Pascoe, W S; Schmidt, C; Kemler, R; Evans, M J; Allen, N D

1993-01-01

A method for the production of embryonic stem (ES) cell-embryo chimeras was developed that involves the simple coculture of eight-cell embryos on a lawn of ES cells. After coculture, the embryos with ES cells attached are transferred to normal embryo culture medium and allowed to develop to the blastocyst stage before reimplantation into foster mothers. Although the ES cells initially attach to the outside of the embryos, they primarily colonize the inner cell mass and its derivatives. This method results in the efficient production of chimeras with high levels of chimerism including the germ line. As embryos are handled en masse and manipulative steps are minimal, this method should greatly reduce the time and effort required to produce chimeric mice. Images Fig. 1 Fig. 2 PMID:8506303

Endometrial signals improve embryo outcome: functional role of vascular endothelial growth factor isoforms on embryo development and implantation in mice.

PubMed

Binder, N K; Evans, J; Gardner, D K; Salamonsen, L A; Hannan, N J

2014-10-10

Does vascular endothelial growth factor (VEGF) have important roles during early embryo development and implantation? VEGF plays key roles during mouse preimplantation embryo development, with beneficial effects on time to cavitation, blastocyst cell number and outgrowth, as well as implantation rate and fetal limb development. Embryo implantation requires synchronized dialog between maternal cells and those of the conceptus. Following ovulation, secretions from endometrial glands increase and accumulate in the uterine lumen. These secretions contain important mediators that support the conceptus during the peri-implantation phase. Previously, we demonstrated a significant reduction of VEGFA in the uterine cavity of women with unexplained infertility. Functional studies demonstrated that VEGF significantly enhanced endometrial epithelial cell adhesive properties and embryo outgrowth. Human endometrial lavages (n = 6) were obtained from women of proven fertility. Four-week old Swiss mice were superovulated and mated with Swiss males to obtain embryos for treatment with VEGF in vitro. Preimplantation embryo development was assessed prior to embryo transfer (n = 19-30/treatment group/output). Recipient F1 female mice (8-12 weeks of age) were mated with vasectomized males to induce pseudopregnancy and embryos were transferred. On Day 14.5 of pregnancy, uterine horns were collected for analysis of implantation rates as well as placental and fetal development (n = 14-19/treatment). Lavage fluid was assessed by western immunoblot analysis to determine the VEGF isoforms present. Mouse embryos were treated with either recombinant human (rh)VEGF, or VEGF isoforms 121 and 165. Preimplantation embryo development was quantified using time-lapse microscopy. Blastocysts were (i) stained for cell number, (ii) transferred to wells coated with fibronectin to examine trophoblast outgrowth or (iii) transferred to pseudo pregnant recipients to analyze implantation rates, placental and fetal development. Western blot analysis revealed the presence of VEGF121 and 165 isoforms in human uterine fluid. Time-lapse microscopy analysis revealed that VEGF (n = 22) and VEGF121 (n = 23) treatment significantly reduced the preimplantation mouse embryo time to cavitation (P < 0.05). VEGF and VEGF165 increased both blastocyst cell number (VEGF n = 27; VEGF165 n = 24: P < 0.001) and outgrowth (n = 15/treatment: 66 h, P < 0.001; 74, 90, 98 and 114 h, P < 0.01) on fibronectin compared with control. Furthermore, rhVEGF improved implantation rates and enhanced fetal limb development (P < 0.05). Due to the nature of this work, embryo development and implantation was only examined in the mouse. The absence or reduction in levels of VEGF during the preimplantation period likely affects key events during embryo development, implantation and placentation. The potential for improvement of clinical IVF outcomes by the addition of VEGF to human embryo culture media needs further investigation. This study was supported by a University of Melbourne Early Career Researcher Grant #601040, the NHMRC (L.A.S., Program grant #494802; Fellowship #1002028; N.J.H., Fellowship # 628927; J.E.; project grant #1047756) and L.A.S., Monash IVF Research and Education Foundation. N.K.B. was supported by an Australian Postgraduate Award. Work at PHI-MIMR Institute was also supported by the Victorian Government's Operational Infrastructure Support Program. There are no conflicts of interest to declare. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cooling strategies for brazilian flounder Paralichthys orbignyanus embryos.

PubMed

Varela, A S; Cardoso, T F; Fernandes E Silva, E; Goularte, K L; Okamoto, M H; Sampaio, L A; Jardim, R D; Corcini, C D

Paralichthys orbignyanus is the species of the greatest potential for marine and estuarine fish farming in southern Brazil. Consequently, embryo cryopreservation becomes an important tool for increasing their production. To evaluate the effects of cooling protocols on the viability of embryos of P. orbignyanus at two stages of development (neurula and early differentiation of the tail). Control embryos were maintained at 23 degree C and treated embryos were cooled to 15 degree C, 10 degree C and 5 degree C at rapid, moderate and slow cooling rates. Then embryos were maintained at these different temperatures for 30, 60 and 90 min and the loss of viability assessed as hatching rates (HR) and morphologically normal larvae (MNL). The average HR for embryos following cooling was higher for those at the tail stage compared to the neurula stage (P<0.05). In both stages there was no statistical difference between the HR of control embryos and those exposed to rapid cooling. Also for tail stage embryos, there was no difference between MNL of control and rapidly cooled embryos. As first steps in the development of cryopreservation methods for P. orbignyanus embryos, the use of a rapid cooling and holding at 5 degree C for 30 min are recommended.

Use of infrared imaging to predict the developmental stages and differences in chicken embryos exposed to different photoperiods

NASA Astrophysics Data System (ADS)

Frederick, Rebecca A.; Hsieh, Sheng-Jen; Palomares, Benjamin Giron

2012-06-01

Monitoring development of chicken embryos allows determination of when an egg is not developing and when eggs are close to hatching for more efficient production. Research has been conducted on the effects of temperature fluctuations and light exposure on embryo development; similarities between chicken and mammal embryos; and the use of MRI, tomography, and ultrasound to view specific areas and processes within the embryo. However, there has been little exploration of the use of infrared imaging as a non-destructive method for analyzing and predicting embryonic development. In this study, we built an automated loading system for image acquisition. Pilot experiments were conducted to determine the overall scanning time and scanning frequency. A batch of fertilized eggs was scanned each day as the embryos continued to grow. The captured images were analyzed and categorized into three stages: Stage 1 (days 1 to 7), Stage 2 (days 8 to 14), and Stage 3 (days 15 to 21). The temperature data abstracted from the captured images were divided into two groups. Group 1, consisting of two-thirds of the data, was used to construct a model. Group 2, consisting of one-third of the data, was used to evaluate the predictive accuracy of the model. A three-layer artificial neural network model was developed to predict embryo development stage given a temperature profile. Results suggest that the neural network model is sufficient to predict embryo development stage with good accuracy of 75%. Accuracy can likely be improved if more data sets for each development stage are available.

Oxidative Damage to Rhesus Macaque Spermatozoa Results in Mitotic Arrest and Transcript Abundance Changes in Early Embryos1

PubMed Central

Burruel, Victoria; Klooster, Katie L.; Chitwood, James; Ross, Pablo J.; Meyers, Stuart A.

2013-01-01

ABSTRACT Our objective was to determine whether oxidative damage of rhesus macaque sperm induced by reactive oxygen species (ROS) in vitro would affect embryo development following intracytoplasmic sperm injection (ICSI) of metaphase II (MII) oocytes. Fresh rhesus macaque spermatozoa were treated with ROS as follows: 1 mM xanthine and 0.1 U/ml xanthine oxidase (XXO) at 37°C and 5% CO2 in air for 2.25 h. Sperm were then assessed for motility, viability, and lipid peroxidation. Motile ROS-treated and control sperm were used for ICSI of MII oocytes. Embryo culture was evaluated for 3 days for development to the eight-cell stage. Embryos were fixed and stained for signs of cytoplasmic and nuclear abnormalities. Gene expression was analyzed by RNA-Seq in two-cell embryos from control and treated groups. Exposure of sperm to XXO resulted in increased lipid peroxidation and decreased sperm motility. ICSI of MII oocytes with motile sperm induced similar rates of fertilization and cleavage between treatments. Development to four- and eight-cell stage was significantly lower for embryos generated with ROS-treated sperm than for controls. All embryos produced from ROS-treated sperm demonstrated permanent embryonic arrest and varying degrees of degeneration and nuclear fragmentation, changes that are suggestive of prolonged senescence or apoptotic cell death. RNA-Seq analysis of two-cell embryos showed changes in transcript abundance resulting from sperm treatment with ROS. Differentially expressed genes were enriched for processes associated with cytoskeletal organization, cell adhesion, and protein phosphorylation. ROS-induced damage to sperm adversely affects embryo development by contributing to mitotic arrest after ICSI of MII rhesus oocytes. Changes in transcript abundance in embryos destined for mitotic arrest is evident at the two-cell stage of development. PMID:23904511

New data about the suspensor of succulent angiosperms: Ultrastructure and cytochemical study of the embryo-suspensor of Sempervivum arachnoideum L. and Jovibarba sobolifera (Sims) Opiz.

PubMed

Kozieradzka-Kiszkurno, Małgorzata; Płachno, Bartosz Jan; Bohdanowicz, Jerzy

2012-07-01

The development of the suspensor in two species - Sempervivum arachnoideum and Jovibarba sobolifera - was investigated using cytochemical methods, light and electron microscopy. Cytological processes of differentiation in the embryo-suspensor were compared with the development of embryo-proper. The mature differentiated suspensor consists of a large basal cell and three to four chalazal cells. The basal cell produces haustorial branched invading ovular tissues. The walls of the haustorium and the micropylar part of the basal cell form the wall ingrowths typical for a transfer cells. The ingrowths also partially cover the lateral wall and the chalazal wall separating the basal cell from the other embryo cells. The dense cytoplasm filling the basal cell is rich in: numerous polysomes lying free or covering rough endoplasmic reticulum (RER), active dictyosomes, microtubules, bundles of microfilaments, microbodies, mitochondria, plastids and lipid droplets. Cytochemical tests (including proteins, insoluble polysaccharides and lipids are distributed in the suspensor during different stages of embryo development) showed the presence of high amounts of macromolecules in the suspensor cells, particularly during the globular and heart-shaped phases of embryo development. The protein bodies and lipid droplets are the main storage products in the cells of the embryo-proper. The results of Auramine 0 indicate that a cuticular material is present only on the surface walls of the embryo-proper, but is absent from the suspensor cell wall. The ultrastructural features and cytochemical tests indicate that in the two species - S. arachnoideum and J. sobolifera - the embryo-suspensor is mainly involved in the absorption and transport of metabolites from the ovular tissues to the developing embryo-proper.

The relevance and use of mouse embryo bioassays for quality control in an assisted reproductive technology program.

PubMed

Scott, L F; Sundaram, S G; Smith, S

1993-09-01

To define both the limits of a mouse embryo bioassay for quality control in an assisted reproductive technology (ART) program and the areas where it can be effectively used. Embryos at the pronuclear and two-cell stage from three different strains of mice were used to assess the effectiveness of this assay for media quality control using five different media routinely used in ART. Pronuclear and two-cell embryos from CD-1 mice were used to test the ability of a mouse embryo bioassay to control for water quality, contaminants in the culture system, and fluctuations in the environmental conditions using a medium, culture system, and scoring technique that were optimized for this strain. The mouse embryo bioassay is not effective in differentiating media appropriate for supporting human embryo development since the development of mouse embryos in vitro is strain, stage, and media related. However, CD-1 embryos were shown to be sensitive to variations in water quality, pH, temperature, incubator conditions, and contaminants in the system when grown in a protein-free medium optimized for their development. Both total blastocyst number and the cell count in the blastocysts were affected. Pronuclear embryos were more sensitive to perturbations in the culture system than two-cell embryos. A mouse embryo bioassay can be effectively used as a means of quality control of water, chemicals, and contact materials and for technique standardization and training in an assisted reproduction program. All the conditions of the test should be defined, pronuclear embryos should be used, and the end point should be fully expanded blastocysts and/or cell numbers in these blastocysts where appropriate.

Efficient Term Development of Vitrified Ferret Embryos Using a Novel Pipette Chamber Technique1

PubMed Central

Sun, Xingshen; Li, Ziyi; Yi, Yaling; Chen, Juan; Leno, Gregory H.; Engelhardt, John F.

2008-01-01

Development of an efficient cryopreservation technique for the domestic ferret is key for the long-term maintenance of valuable genetic specimens of this species and for the conservation of related endangered species. Unfortunately, current cryopreservation procedures, such as slow-rate freezing and vitrification with open pulled straws, are inefficient. In this report, we describe a pipette tip-based vitrification method that significantly improves the development of thawed ferret embryos following embryo transfer (ET). Ferret embryos at the morula (MR), compact morula (CM), and early blastocyst (EB) stages were vitrified using an Eppendorf microloader pipette tip as the chamber vessel. The rate of in vitro development was significantly (P < 0.05) higher among embryos vitrified at the CM (93.6%) and EB (100%) stages relative to those vitrified at the MR stages (58.7%). No significant developmental differences were observed when comparing CM and EB vitrified embryos with nonvitrified control CM (100%) and EB (100%) embryos. In addition, few differences in the ultrastructure of intracellular lipid droplets or in microfilament structure were observed between control embryos and embryos vitrified at any developmental stage. Vitrified-thawed CM/EB embryos cultured for 2 or 16 h before ET resulted in live birth rates of 71.3% and 77.4%, respectively. These rates were not significantly different from the control live birth rate (79.2%). However, culture for 32 h (25%) or 48 h (7.8%) after vitrification significantly reduced the rate of live births. These data indicate that the pipette chamber vitrification technique significantly improves the live birth rate of transferred ferret embryos relative to current state-of-the-art methods.. PMID:18633142

Impact of PCOS on early embryo cleavage kinetics.

PubMed

Wissing, M L; Bjerge, M R; Olesen, A I G; Hoest, T; Mikkelsen, A L

2014-04-01

This study investigated whether polycystic ovary syndrome (PCOS) affected early embryo development assessed by time-lapse analysis of embryo kinetics from fertilization to the blastocyst stage. This was a prospective cohort study of two pronuclei (2PN) embryos from 25 hyperandrogenic PCOS patients (110 2PN embryos), 26 normoandrogenic PCOS patients (140 2PN embryos) and 20 healthy, regularly cycling women (controls, 97 2PN embryos). Patients underwent the same baseline evaluation and the same ovarian stimulation from April 2010 to February 2013. Oocytes were fertilized by intracytoplasmic sperm injection and incubated in an EmbryoScope with pictures taken every 20 min in seven focal planes. Time to 2PN breakdown, first cleavage and cleavage to 3, 4, 5, 6, 7 and 8 cells, morula and blastocyst (t₂, t₃, t₄, t₅, t₆, t₇, t₈, t(M), t(B)) were annotated. Differences in embryo kinetics between groups were assessed by mixed modelling. Compared with controls, embryos from hyperandrogenic PCOS patients were significantly delayed at 2PN breakdown, t₂, t₃, t₄ and t₇ but not at t₅, t₆, t₈, t(M) or t(B). Embryos from hyperandrogenic PCOS women had developed slower from fertilization to the 8-cell stage compared with embryos from controls. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Nuclear Reprogramming: Kinetics of Cell Cycle and Metabolic Progression as Determinants of Success

PubMed Central

Balbach, Sebastian Thomas; Esteves, Telma Cristina; Houghton, Franchesca Dawn; Siatkowski, Marcin; Pfeiffer, Martin Johannes; Tsurumi, Chizuko; Kanzler, Benoit; Fuellen, Georg; Boiani, Michele

2012-01-01

Establishment of totipotency after somatic cell nuclear transfer (NT) requires not only reprogramming of gene expression, but also conversion of the cell cycle from quiescence to the precisely timed sequence of embryonic cleavage. Inadequate adaptation of the somatic nucleus to the embryonic cell cycle regime may lay the foundation for NT embryo failure and their reported lower cell counts. We combined bright field and fluorescence imaging of histone H2b-GFP expressing mouse embryos, to record cell divisions up to the blastocyst stage. This allowed us to quantitatively analyze cleavage kinetics of cloned embryos and revealed an extended and inconstant duration of the second and third cell cycles compared to fertilized controls generated by intracytoplasmic sperm injection (ICSI). Compared to fertilized embryos, slow and fast cleaving NT embryos presented similar rates of errors in M phase, but were considerably less tolerant to mitotic errors and underwent cleavage arrest. Although NT embryos vary substantially in their speed of cell cycle progression, transcriptome analysis did not detect systematic differences between fast and slow NT embryos. Profiling of amino acid turnover during pre-implantation development revealed that NT embryos consume lower amounts of amino acids, in particular arginine, than fertilized embryos until morula stage. An increased arginine supplementation enhanced development to blastocyst and increased embryo cell numbers. We conclude that a cell cycle delay, which is independent of pluripotency marker reactivation, and metabolic restraints reduce cell counts of NT embryos and impede their development. PMID:22530006

Insights on blastomere nuclearity.

PubMed

Gil, Mónica; D'Ommar, Gustavo; Póo, Maria E; Sosa, Anna; Piras, Marta; Piras, Romano; Rísquez, Francisco

2007-01-01

To analyze the results of our transferred embryos, especially those that "changed" their blastomere nuclearity from Multinucleated (MN) to Mono-nucleated during development. Pregnancies where at least one MN embryo was transferred were retrospectively evaluated and categorized in order to record and follow-up on the ones that were implanted. Embryos were classified as normal (when all blastomeres were mono-nucleated on day one and two of development), corrected (multinucleated embryos on day one that became mono-nucleated on day two) and non-corrected (multinucleated either on day one, on day two or both days). There were 633 transfer cycles analyzed. Thirty-three percent (206) had at least one embryo with a MN blastomere at a given stage of development. Pregnancy and implantation rates were 29.0% and 19.0% for the group of exclusively mono-nucleated embryo transfers, and 28.6% and 15.8% for the group with at least one MN embryo transferred. The pregnancy outcome for "corrected" and "non-corrected" embryos could be corroborated unequivocally in only 9 cases, with an outcome of 8 and 4 normal babies, respectively. Because the amount of data analyzed is not satisfactorily large, differences were not significantly different; however, a trend may exist showing that normal at term pregnancies obtained from corrected embryos are more likely to occur than those from non-corrected embryos. Nuclear observation on a daily basis should be one of the strategies used to select the best embryos for transferring, to improve implantation rates and avoid multiple pregnancies.

Role of nucleation-promoting factors in mouse early embryo development.

PubMed

Wang, Qiao-Chu; Liu, Jun; Wang, Fei; Duan, Xing; Dai, Xiao-Xin; Wang, Teng; Liu, Hong-Lin; Cui, Xiang-Shun; Sun, Shao-Chen; Kim, Nam-Hyung

2013-06-01

During mitosis nucleation-promoting factors (NPFs) bind to the Arp2/3 complex and activate actin assembly. JMY and WAVE2 are two critical members of the NPFs. Previous studies have demonstrated that NPFs promote multiple processes such as cell migration and cytokinesis. However, the role of NPFs in development of mammalian embryos is still unknown. Results of the present study show that the NPFs JMY and WAVE2 are critical for cytokinesis during development of mouse embryos. Both JMY and WAVE2 are expressed in mouse embryos. After injection of JMY or WAVE2 siRNA, all embryos failed to develop to the morula or blastocyst stages. Moreover, using fluorescence intensity analysis, we found that the expression of actin decreased, and multiple nuclei were observed within a single cell indicating that NPFs-induced actin reduction caused the failure of cell division. In addition, injection of JMY and WAVE2 siRNA also caused ARP2 degradation, indicating that involvement of NPFs in development of mouse embryos is mainly through regulation of ARP2/3-induced actin assembly. Taken together, these data suggested that WAVE2 and JMY are involved in development of mouse embryos, and their regulation may be through a NPFs-Arp2/3-actin pathway.

Effect of sperm entry on blastocyst development after in vitro fertilization and intracytoplasmic sperm injection - mouse model.

PubMed

Piotrowska-Nitsche, Karolina; Chan, Anthony W S

2013-01-01

To investigate whether in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), influence the embryo's development and its quality using the mouse as a model. Assisted fertilization was performed using ICSI and IVF. Fluorescent beads were adhered to the fertilization cone or place of previous sperm injection in the natural mated (NM), IVF and ICSI embryos, respectively. Embryo examination was carried out at the two-cell and blastocyst stage to determine the position of fluorescent bead. Protein expression was detected by fluorescence immunocytochemical staining and confocal microscopic imaging of blastocysts. IVF and ICSI embryos developed at rates comparable to NM group. Embryos show similar expression patterns of two transcription factors, Oct4 and Cdx2. The most preferred place for spermatozoa attachment was the equatorial site of the egg, whether fertilization occurred in vitro or under natural conditions. We also link the sperm entry position (SEP) to embryo morphology and the number of cells at the blastocyst stage, with no influence of the method of fertilization. IVF and ICSI, do not compromise in vitro pre-implantation development. Additional data, related to sperm entry, could offer further criteria to predict embryos that will implant successfully. Based on embryo morphology, developmental rate and protein expression level of key transcription factors, our results support the view that ART techniques, such as IVF and ICSI, do not perturb embryonic development or quality.

Cryotolerance of Day 2 or Day 6 in vitro produced ovine embryos after vitrification by Cryotop or Spatula methods.

PubMed

Dos Santos Neto, P C; Vilariño, M; Barrera, N; Cuadro, F; Crispo, M; Menchaca, A

2015-02-01

This study was conducted to evaluate the cryotolerance of in vitro produced ovine embryos submitted to vitrification at different developmental stages using two methods of minimum volume and rapid cooling rate. Embryos were vitrified at early stage (2 to 8-cells) on Day 2 or at advanced stage (morulae and blastocysts) on Day 6 after in vitro fertilization. Vitrification procedure consisted of the Cryotop (Day 2, n=165; Day 6, n=174) or the Spatula method (Day 2, n=165; Day 6, n=175). Non vitrified embryos were maintained in in vitro culture as a control group (n=408). Embryo survival was determined at 3h and 24h after warming, development and hatching rates were evaluated on Day 6 and Day 8 after fertilization, and total cell number was determined on expanded blastocysts. Embryo survival at 24h after warming increased as the developmental stage progressed (P<0.05) and was not affected by the vitrification method. The ability for hatching of survived embryos was not affected by the stage of the embryos at vitrification or by the vitrification method. Thus, the proportion of hatching from vitrified embryos was determined by the survival rate and was lower for Day 2 than Day 6 vitrified embryos. The percentage of blastocysts on Day 8 was lower for the embryos vitrified on Day 2 than Day 6 (P<0.05), and was lower for both days of vitrification than for non-vitrified embryos (P<0.05). No interaction of embryo stage by vitrification method was found (P=NS) and no significant difference was found in the blastocyst cell number among vitrified and non-vitrified embryos. In conclusion, both methods using minimum volume and ultra-rapid cooling rate allow acceptable survival and development rates in Day 2 and Day 6 in vitro produced embryos in sheep. Even though early stage embryos showed lower cryotolerance, those embryos that survive the vitrification-warming process show high development and hatching rates, similar to vitrification of morulae or blastocysts. Copyright © 2014 Elsevier Inc. All rights reserved.

A three-dimensional culture system using alginate hydrogel prolongs hatched cattle embryo development in vitro.

PubMed

Zhao, Shuan; Liu, Zhen-Xing; Gao, Hui; Wu, Yi; Fang, Yuan; Wu, Shuai-Shuai; Li, Ming-Jie; Bai, Jia-Hua; Liu, Yan; Evans, Alexander; Zeng, Shen-Ming

2015-07-15

No successful method exists to maintain the three-dimensional architecture of hatched embryos in vitro. Alginate, a linear polysaccharide derived from brown algae, has characteristics that make it an ideal material as a three-dimensional (3D) extracellular matrix for in vitro cell, tissue, or embryo culture. In this study, alginate hydrogel was used for IVC of posthatched bovine embryos to observe their development under the 3D system. In vitro-fertilized and parthenogenetically activated posthatched bovine blastocysts were cultured in an alginate encapsulation culture system (AECS), an alginate overlay culture system (AOCS), or control culture system. After 18 days of culture, the survival rate of embryos cultured in AECS was higher than that in the control group (P < 0.05), and the embryos were expanded and elongated in AECS with the maximal length of 1.125 mm. When the AECS shrinking embryos were taken out of the alginate beads on Day 18 and cultured in the normal culture system, 9.09% of them attached to the bottoms of the plastic wells and grew rapidly, with the largest area of an attached embryo being 66.00 mm(2) on Day 32. The embryos cultured in AOCS developed monovesicular or multivesicular morphologies. Total cell number of the embryos cultured in AECS on Day 19 was significantly higher than that of embryos on Day 8. Additionally, AECS and AOCS supported differentiation of the embryonic cells. Binuclear cells were visible in Day-26 adherent embryos, and the messenger RNA expression patterns of Cdx2 and Oct4 in AOCS-cultured embryos were similar to those in vivo embryos, whereas IFNT and ISG15 messenger RNA were still expressed in Day-26 and Day-32 prolong-cultured embryos. In conclusion, AECS and AOCS did support cell proliferation, elongation, and differentiation of hatched bovine embryos during prolonged IVC. The culture system will be useful to further investigate the molecular mechanisms controlling ruminant embryo elongation and implantation. Copyright © 2015 Elsevier Inc. All rights reserved.

Production of rhesus monkey cloned embryos expressing monomeric red fluorescent protein by interspecies somatic cell nuclear transfer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Hai-Ying; Kang, Jin-Dan; Li, Suo

2014-02-21

Highlights: • Rhesus monkey cells were electroporated with a plasmid containing mRFP1, and an mRFP1-expressing cell line was generated. • For the first time, mRFP1-expressing rhesus monkey cells were used as donor cells for iSCNT. • The effect of VPA on the development of embryos cloned using iSCNT was determined. - Abstract: Interspecies somatic cell nuclear transfer (iSCNT) is a promising method to clone endangered animals from which oocytes are difficult to obtain. Monomeric red fluorescent protein 1 (mRFP1) is an excellent selection marker for transgenically modified cloned embryos during somatic cell nuclear transfer (SCNT). In this study, mRFP-expressing rhesusmore » monkey cells or porcine cells were transferred into enucleated porcine oocytes to generate iSCNT and SCNT embryos, respectively. The development of these embryos was studied in vitro. The percentage of embryos that underwent cleavage did not significantly differ between iSCNT and SCNT embryos (P > 0.05; 71.53% vs. 80.30%). However, significantly fewer iSCNT embryos than SCNT embryos reached the blastocyst stage (2.04% vs. 10.19%, P < 0.05). Valproic acid was used in an attempt to increase the percentage of iSCNT embryos that developed to the blastocyst stage. However, the percentages of embryos that underwent cleavage and reached the blastocyst stage were similar between untreated iSCNT embryos and iSCNT embryos treated with 2 mM valproic acid for 24 h (72.12% vs. 70.83% and 2.67% vs. 2.35%, respectively). These data suggest that porcine-rhesus monkey interspecies embryos can be generated that efficiently express mRFP1. However, a significantly lower proportion of iSCNT embryos than SCNT embryos reach the blastocyst stage. Valproic acid does not increase the percentage of porcine-rhesus monkey iSCNT embryos that reach the blastocyst stage. The mechanisms underling nuclear reprogramming and epigenetic modifications in iSCNT need to be investigated further.« less

Additional mitochondrial DNA influences the interactions between the nuclear and mitochondrial genomes in a bovine embryo model of nuclear transfer.

PubMed

Srirattana, Kanokwan; St John, Justin C

2018-05-08

We generated cattle embryos using mitochondrial supplementation and somatic cell nuclear transfer (SCNT), named miNT, to determine how additional mitochondrial DNA (mtDNA) modulates the nuclear genome. To eliminate any confounding effects from somatic cell mtDNA in intraspecies SCNT, donor cell mtDNA was depleted prior to embryo production. Additional oocyte mtDNA did not affect embryo development rates but increased mtDNA copy number in blastocyst stage embryos. Moreover, miNT-derived blastocysts had different gene expression profiles when compared with SCNT-derived blastocysts. Additional mtDNA increased expression levels of genes involved in oxidative phosphorylation, cell cycle and DNA repair. Supplementing the embryo culture media with a histone deacetylase inhibitor, Trichostatin A (TSA), had no beneficial effects on the development of miNT-derived embryos, unlike SCNT-derived embryos. When compared with SCNT-derived blastocysts cultured in the presence of TSA, additional mtDNA alone had beneficial effects as the activity of glycolysis may increase and embryonic cell death may decrease. However, these beneficial effects were not found with additional mtDNA and TSA together, suggesting that additional mtDNA alone enhances reprogramming. In conclusion, additional mtDNA increased mtDNA copy number and expression levels of genes involved in energy production and embryo development in blastocyst stage embryos emphasising the importance of nuclear-mitochondrial interactions.

Climatic factors affecting quantity and quality grade of in vivo derived embryos of cattle.

PubMed

Chinchilla-Vargas, Josué; Jahnke, Marianna M; Dohlman, Tyler M; Rothschild, Max F; Gunn, Patrick J

2018-05-01

The present study investigated the effects of climatic variables on the quality grade and quantity of in vivo derived cattle embryos in the Midwestern United States. Climatic information included greatest and least daily temperature, average daily wind speed and average temperature-humidity index for each of the 765 records. The response variables included the number of ovarian structures, viable embryos, quality grade 1 embryos, quality grade 2 embryos, quality grade 3 embryos, freezable embryos (sum of quality grade 1 and quality grade 2 embryos), transferable embryos (sum of quality grade 1-3 embryos), degenerate embryos and unfertilized ova. Measures for variables among the breeds of donors and sires grouped by geographical origin were compared. A negative effect of greater temperatures during the early embryonic development stage tended (P < 0.10) to be associated with a decrease in the quality of embryos recovered. Interestingly, the greater the Temperature-Humidity Index (THI) during the early ovarian antral follicular development stage 40-45 days prior to ovulation was associated with a tendency for greater numbers of total number of freezable and transferable embryos recovered per uterine flushing (P < 0.10). Increased wind speed at the early antral follicular phase 40-45 days prior to ovulation was associated with an increase in the percentage of quality grade 1 embryos recovered (P < 0.05). Wind speed during the estrous synchronization period was also associated with a lesser number of embryos recovered (P < 0.05). This retrospective study confirms that climatic variables have significant effects on the in vivo production of cattle embryos and that wind speed should be considered in future analyses of factors affecting embryo quality. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of ambient light exposure of media and embryos on development and quality of porcine parthenogenetically activated embryos.

PubMed

Li, Rong; Liu, Ying; Pedersen, Hanne Skovsgaard; Callesen, Henrik

2015-06-01

Light exposure is a common stress factor during in vitro handling of oocytes and embryos that originates from both microscope and ambient light. In the current study, the effect of two types of ambient light (daylight and laboratory light) on porcine parthenogenetically activated (PA) embryos was tested in two experiments: (1) ambient light on medium subsequently used for embryo in vitro development; and (2) ambient light exposure on activated oocytes before in vitro development. The results from Experiment 1 showed that exposure of culture medium to both types of ambient light decreased the percentage of blastocysts that showed good morphology, only after 24 h exposure. The results from Experiment 2 revealed a reduction in both blastocyst formation and quality when activated oocytes were exposed to both types of ambient light. This effect was seen after only 1 h exposure and increased with time. In conclusion, exposure to ambient light can be harmful to embryo development, both when medium is exposed for a long period of time and, to a greater extent, when the embryo itself is exposed for >1 h. In practice, it is therefore recommended to protect both culture medium and porcine embryos against ambient light during in vitro handling in the laboratory.

Development of a green fluorescent protein metastatic-cancer chick-embryo drug-screen model.

PubMed

Bobek, Vladimir; Plachy, Jiri; Pinterova, Daniela; Kolostova, Katarina; Boubelik, Michael; Jiang, Ping; Yang, Meng; Hoffman, Robert M

2004-01-01

The chick-embryo model has been an important tool to study tumor growth, metastasis, and angiogenesis. However, an imageable model with a genetic fluorescent tag in the growing and spreading cancer cells that is stable over time has not been developed. We report here the development of such an imageable fluorescent chick-embryo metastatic cancer model with the use of green fluorescent protein (GFP). Lewis lung carcinoma cells, stably expressing GFP, were injected on the 12th day of incubation in the chick embryo. GFP-Lewis lung carcinoma metastases were visualized by fluorescence, after seven days additional incubation, in the brain, heart, and sternum of the developing chick embryo, with the most frequent site being the brain. The combination of streptokinase and gemcitabine was evaluated in this GFP metastatic model. Twelve-day-old chick embryos were injected intravenously with GFP-Lewis lung cancer cells, along with these two agents either alone or in combination. The streptokinase-gemcitabine combination inhibited metastases at all sites. The effective dose of gemcitabine was found to be 10 mg/kg and streptokinase 2000 IU per embryo. The data in this report suggest that this new stably fluorescent imageable metastatic-cancer chick-embryo model will enable rapid screening of new antimetastatic agents.

A mathematical model of in vivo bovine blastocyst developmental to gestational Day 15.

PubMed

Shorten, P R; Donnison, M; McDonald, R M; Meier, S; Ledgard, A M; Berg, D

2018-06-20

Bovine embryo growth involves a complex interaction between the developing embryo and the growth-promoting potential of the uterine environment. We have previously established links between embryonic factors (embryo stage, embryo gene expression), maternal factors (progesterone, body condition score), and embryonic growth to 8 d after bulk transfer of Day 7 in vitro-produced blastocysts. In this study we recovered blastocysts on Days 7 and 15 after artificial insemination to test the hypothesis that in vivo and in vitro embryos follow a similar growth program. We conducted our study using 4 commercial farms and repeated our study over 2 yr (2014, 2015), with data available from 2 of the 4 farms in the second year. Morphological and gene expression measurements (196 candidate genes) of the Day 7 embryos were measured and the progesterone concentration of the cows were measured throughout the reproductive cycle as a reflection of the state of the uterine environment. These data were also used to assess the interaction between the uterine environment and the developing embryo and to examine how well Day 7 embryo stage can be predicted from the Day 7 gene expression profile. Progesterone was not a strong predictor of in vivo embryo growth to Day 15. This contrasts with a range of Day 7 embryo transfer studies which demonstrated that progesterone is a very good predictor of embryo growth to Day 15. Our analysis demonstrates that in vivo embryos are 3 times less sensitive to progesterone than in vitro-transferred embryos (up to Day 15). This highlights that caution must be applied when extrapolating the results of in vitro embryo transfer studies to the in vivo situation. The similar variance in measured and predicted (based on Day 15 length) Day 7 embryo stage indicate low stochastic perturbations for in vivo embryo growth (large stochastic growth effects would generate a significantly larger standard deviation in measured embryo length on Day 15). We also identified that Day 7 embryo stage could be predicted based on the Day 7 gene expression profile (58% overall success rate for classification of 5 embryo stages). Our analysis also associated genes with each developmental stage and demonstrates the high level of temporal regulation of genes that occurs during early embryonic development. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Loss of maternal CTCF is associated with peri-implantation lethality of Ctcf null embryos.

PubMed

Moore, James M; Rabaia, Natalia A; Smith, Leslie E; Fagerlie, Sara; Gurley, Kay; Loukinov, Dmitry; Disteche, Christine M; Collins, Steven J; Kemp, Christopher J; Lobanenkov, Victor V; Filippova, Galina N

2012-01-01

CTCF is a highly conserved, multifunctional zinc finger protein involved in critical aspects of gene regulation including transcription regulation, chromatin insulation, genomic imprinting, X-chromosome inactivation, and higher order chromatin organization. Such multifunctional properties of CTCF suggest an essential role in development. Indeed, a previous report on maternal depletion of CTCF suggested that CTCF is essential for pre-implantation development. To distinguish between the effects of maternal and zygotic expression of CTCF, we studied pre-implantation development in mice harboring a complete loss of function Ctcf knockout allele. Although we demonstrated that homozygous deletion of Ctcf is early embryonically lethal, in contrast to previous observations, we showed that the Ctcf nullizygous embryos developed up to the blastocyst stage (E3.5) followed by peri-implantation lethality (E4.5-E5.5). Moreover, one-cell stage Ctcf nullizygous embryos cultured ex vivo developed to the 16-32 cell stage with no obvious abnormalities. Using a single embryo assay that allowed both genotype and mRNA expression analyses of the same embryo, we demonstrated that pre-implantation development of the Ctcf nullizygous embryos was associated with the retention of the maternal wild type Ctcf mRNA. Loss of this stable maternal transcript was temporally associated with loss of CTCF protein expression, apoptosis of the developing embryo, and failure to further develop an inner cell mass and trophoectoderm ex vivo. This indicates that CTCF expression is critical to early embryogenesis and loss of its expression rapidly leads to apoptosis at a very early developmental stage. This is the first study documenting the presence of the stable maternal Ctcf transcript in the blastocyst stage embryos. Furthermore, in the presence of maternal CTCF, zygotic CTCF expression does not seem to be required for pre-implantation development.

Cell wall invertase as a regulator in determining sequential development of endosperm and embryo through glucose signaling early in seed development.

PubMed

Wang, Lu; Liao, Shengjin; Ruan, Yong-Ling

2013-01-01

Seed development depends on coordination among embryo, endosperm and seed coat. Endosperm undergoes nuclear division soon after fertilization, whereas embryo remains quiescent for a while. Such a developmental sequence is of great importance for proper seed development. However, the underlying mechanism remains unclear. Recent results on the cellular domain- and stage-specific expression of invertase genes in cotton and Arabidopsis revealed that cell wall invertase may positively and specifically regulate nuclear division of endosperm after fertilization, thereby playing a role in determining the sequential development of endosperm and embryo, probably through glucose signaling.

Paternal Diet-Induced Obesity Retards Early Mouse Embryo Development, Mitochondrial Activity and Pregnancy Health

PubMed Central

Binder, Natalie K.; Hannan, Natalie J.; Gardner, David K.

2012-01-01

Worldwide, 48% of adult males are overweight or obese. An association between infertility and excessive body weight is now accepted, although focus remains primarily on females. It has been shown that parental obesity results in compromised embryo development, disproportionate changes in embryo metabolism and reduced blastocyst cell number. The aim of this study was to determine whether paternal obesity has negative effects on the resultant embryo. Specifically, using in vitro fertilisation (IVF), we wanted to isolate the functional effects of obesity on sperm by examining the subsequent embryo both pre- and post-implantation. Epididymal sperm was collected from age matched normal and obese C57BL/6 mice and cryopreserved for subsequent IVF with oocytes collected from Swiss females (normal diet/weight). Obesity was induced in male mice by feeding a high fat diet of 22% fat for 10 weeks. Resultant embryos were cultured individually and development monitored using time-lapse microscopy. Paternal obesity resulted in a significant delay in preimplantation embryo development as early as syngamy (P<0.05). Metabolic parameters were measured across key developmental stages, demonstrating significant reduction in mitochondrial membrane potential (P<0.01). Blastocysts were stained to determine trophectoderm (TE) and inner cell mass (ICM) cell numbers, revealing significant differences in the ratio of cell allocation to TE and ICM lineages (P<0.01). Functional studies examining blastocyst attachment, growth and implantation demonstrated that blastocysts derived from sperm of obese males displayed significantly reduced outgrowth on fibronectin in vitro (P<0.05) and retarded fetal development in vivo following embryo transfer (P<0.05). Taken together, these data clearly demonstrate that paternal obesity has significant negative effects on the embryo at a variety of key early developmental stages, resulting in delayed development, reduced placental size and smaller offspring. PMID:23300638

Effect of exogenous transforming growth factor β1 (TGF-β1) on early bovine embryo development.

PubMed

Barrera, Antonio D; García, Elina V; Miceli, Dora C

2018-06-08

SummaryDuring preimplantation development, embryos are exposed and have the capacity to respond to different growth factors present in the maternal environment. Among these factors, transforming growth factor β1 (TGF-β1) is a well known modulator of embryonic growth and development. However, its action during the first stages of development, when the embryo transits through the oviduct, has not been yet elucidated. The objective of the present study was to examine the effect of early exposure to exogenous TGF-β1 on embryo development and expression of pluripotency (OCT4, NANOG) and DNA methylation (DNMT1, DNMT3A, DNMT3B) genes in bovine embryos produced in vitro. First, gene expression analysis of TGF-β receptors confirmed a stage-specific expression pattern, showing greater mRNA abundance of TGFBR1 and TGFBR2 from the 2- to the 8-cell stage, before embryonic genome activation. Second, embryo culture for the first 48 h in serum-free CR1aa medium supplemented with 50 or 100 ng/ml recombinant TGF-β1 did not affect the cleavage and blastocyst rate (days 7 and 8). However, RT-qPCR analysis showed a significant increase in the relative abundance of NANOG and DNMT3A in the 8-cell stage embryos and expanded blastocysts (day 8) derived from TGF-β1 treated embryos. These results suggest an early action of exogenous TGF-β1 on the bovine embryo, highlighting the importance to provide a more comprehensive understanding of the role of TGF-β signalling during early embryogenesis.

Deciphering the roles of acyl-CoA-binding proteins in plant cells.

PubMed

Lung, Shiu-Cheung; Chye, Mee-Len

2016-09-01

Lipid trafficking is vital for metabolite exchange and signal communications between organelles and endomembranes. Acyl-CoA-binding proteins (ACBPs) are involved in the intracellular transport, protection, and pool formation of acyl-CoA esters, which are important intermediates and regulators in lipid metabolism and cellular signaling. In this review, we highlight recent advances in our understanding of plant ACBP families from a cellular and developmental perspective. Plant ACBPs have been extensively studied in Arabidopsis thaliana (a dicot) and to a lesser extent in Oryza sativa (a monocot). Thus far, they have been detected in the plasma membrane, vesicles, endoplasmic reticulum, Golgi apparatus, apoplast, cytosol, nuclear periphery, and peroxisomes. In combination with biochemical and molecular genetic tools, the widespread subcellular distribution of respective ACBP members has been explicitly linked to their functions in lipid metabolism during development and in response to stresses. At the cellular level, strong expression of specific ACBP homologs in specialized cells, such as embryos, stem epidermis, guard cells, male gametophytes, and phloem sap, is of relevance to their corresponding distinct roles in organ development and stress responses. Other interesting patterns in their subcellular localization and spatial expression that prompt new directions in future investigations are discussed.

In vitro development of cloned bovine embryos produced by handmade cloning using somatic cells from distinct levels of cell culture confluence.

PubMed

Gerger, R P C; Ribeiro, E S; Forell, F; Bertolini, L R; Rodrigues, J L; Ambrósio, C E; Miglino, M A; Mezzalira, A; Bertolini, M

2010-02-18

The relationship between the level of cell confluence near the plateau phase of growth and blastocyst yield following somatic cell cloning is not well understood. We examined the effect of distinct cell culture confluence levels on in vitro development of cloned bovine embryos. In vitro-matured bovine oocytes were manually bisected and selected by DNA staining. One or two enucleated hemi-cytoplasts were paired and fused with an adult skin somatic cell. Cultured skin cells from an adult Nellore cow harvested at three distinct culture confluence levels (70-80, 80-90, and >95%) were used for construction of embryos and hemi-embryos. After activation, structures were cultured in vitro as one embryo (1 x 100%) or as aggregates of two hemi-embryos (2 x 50%) per microwell. Fusion, cleavage and blastocyst rates were compared using the chi(2) test. The fusion rate for hemi-embryos (51.4%) was lower than for embryos (67.6%), with no influence of degree of cell confluence. However, blastocyst rates improved linearly (7.0, 17.5, and 29.4%) with increases in cell confluence. We conclude that degree of cell culture confluence significantly influences subsequent embryo development; use of a cell population in high confluence (>90%) for nuclear transfer significantly improved blastocyst yield after cloning.

Developmental consequences of cryopreservation of mammalian oocytes and embryos.

PubMed

Smith, Gary D; Silva E Silva, Cristine Ane

2004-08-01

During the last three decades, significant advances have been made in successful cryopreservation of mammalian preimplantation embryos, and more recently oocytes. The ability to cryopreserve, thaw, and establish pregnancies with supernumerary preimplantation embryos has become an important tool in fertility treatment. Human oocyte cryopreservation has practical application in preserving fertility for individuals at risk of compromised egg quality due to cancer treatments or advanced maternal age. While oocyte/embryo cryopreservation success has increased over time, there is still room for improvement. Oocytes and embryos are susceptible to cryo-damage, which collectively entails cellular damage caused by mechanical, chemical, or thermal forces during the freeze-thaw process. Basic studies focused on understanding cellular structures, their composition, and more importantly their functions, in normal cell developments will continue to be critical in assessing, understanding, and correcting oocyte/embryo cryo-damage. This review will delineate many of the oocyte/embryo intracellular and extracellular structures that are or may be compromised during cryopreservation. A global theme presented throughout this review is that many structural components of the oocyte/embryo also have essential functional roles in development. Compromising these cellular structures, and thus their cellular homeostatic functions, can deleteriously influence initial cryo-survival or compromise subsequent normal development through effects on the oocyte and/or early embryo.

In vitro production of small ruminant embryos: late improvements and further research.

PubMed

de Souza-Fabjan, Joanna Maria Gonçalves; Panneau, Barbara; Duffard, Nicolas; Locatelli, Yann; de Figueiredo, José Ricardo; Freitas, Vicente José de Figueirêdo; Mermillod, Pascal

2014-06-01

Beyond the potential use of in vitro production of embryos (IVP) in breeding schemes, embryos are also required for the establishment of new biotechnologies such as cloning and transgenesis. Additionally, the knowledge of oocyte and embryo physiology acquired through IVP techniques may stimulate the further development of other techniques such as marker assisted and genomic selection of preimplantation embryos, and also benefit assisted procreation in human beings. Efficient in vitro embryo production is currently a major objective for livestock industries, including small ruminants. The heterogeneity of oocytes collected from growing follicles by laparoscopic ovum pick up or in ovaries of slaughtered females, remains an enormous challenge for IVM success, and still limits the rate of embryo development. In addition, the lower quality of the IVP embryos, compared with their in vivo-derived counterparts, translates into poor cryosurvival, which restricts the wider use of this promising technology. Therefore, many studies have been reported in an attempt to determine the most suitable conditions for IVM, IVF, and in vitro development to maximize embryo production rate and quality. This review aims to present the current panorama of IVP production in small ruminants, describing important steps for its success, reporting the recent advances and also the main obstacles identified for its improvement and dissemination. Copyright © 2014 Elsevier Inc. All rights reserved.

Hybrid embryos produced by transferring panda or cat somatic nuclei into rabbit MII oocytes can develop to blastocyst in vitro.

PubMed

Wen, Duan-Cheng; Bi, Chun-Ming; Xu, Ying; Yang, Cai-Xia; Zhu, Zi-Yu; Sun, Qing-Yuan; Chen, Da-Yuan

2005-08-01

The developmental potential of hybrid embryos produced by transferring panda or cat fibroblasts into nucleated rabbit oocytes was assessed. Both the panda-rabbit and the cat-rabbit hybrid embryos were able to form blastocysts in vitro. However, the rates of attaining the two-cell, four-cell, eight-cell, morula, or blastocyst stages for panda-rabbit hybrids were significantly greater than those of cat-rabbit hybrids (P<0.05). Transferring the rabbit fibroblasts into nucleated rabbit oocytes, 31.0% of the blastocyst rate was obtained, which was significantly higher than that of both the panda-rabbit and the cat-rabbit hybrid embryos (P<0.05). Whether or not the second polar body (PB2) was extruded from the one-cell hybrid embryos (both panda-rabbit and cat-rabbit hybrids) significantly affected their developmental capacity. Embryos without an extruded PB2 showed a higher capacity to develop into blastocysts (panda-rabbit: 19.2%; cat-rabbit: 4.3%), while embryos with extruded PB2 could only develop to the morula stage. The hybrid embryos formed pronucleus-like structures (PN) in 2-4 hr after activation, and the number of PN in one-cell embryos varied from one to five. Tracking of the nucleus in the egg after fusion revealed that the somatic nucleus could approach and aggregate with the oocyte nucleus spontaneously. Chromosome analysis of the panda-rabbit blastocysts showed that the karyotype of the hybrid embryos (2n=86) consisted of chromosomes from both the panda (2n=42) and the rabbit (2n=44). The results demonstrate that (1) it is possible to produce genetic hybrid embryos by interspecies nuclear transfer; (2) the developmental potential of the hybrid embryos is highly correlated to the donor nucleus species; and (3) the hybrid genome is able to support the complete preimplantation embryonic development of the hybrids. Copyright (c) 2005 Wiley-Liss, Inc.

Optimized ex-ovo culturing of chick embryos to advanced stages of development.

PubMed

Cloney, Kellie; Franz-Odendaal, Tamara Anne

2015-01-24

Research in anatomy, embryology, and developmental biology has largely relied on the use of model organisms. In order to study development in live embryos model organisms, such as the chicken, are often used. The chicken is an excellent model organism due to its low cost and minimal maintenance, however they present observational challenges because they are enclosed in an opaque eggshell. In order to properly view the embryo as it develops, the shell must be windowed or removed. Both windowing and ex ovo techniques have been developed to assist researchers in the study of embryonic development. However, each of the methods has limitations and challenges. Here, we present a simple, optimized ex ovo culture technique for chicken embryos that enables the observation of embryonic development from stage HH 19 into late stages of development (HH 40), when many organs have developed. This technique is easy to adopt in both undergraduate classes and more advanced research laboratories where embryo manipulations are conducted.

An Arabidopsis thaliana embryo arrest mutant exhibiting germination potential

USDA-ARS?s Scientific Manuscript database

The ability to initiate radicle elongation, or germination potential, occurs in developing embryos before the completion of seed maturation. Green embryos after walking-stick stage in developing Arabidopsis thaliana seeds germinate when excised from seeds and incubated in MS media containing 1 % suc...

Dynamic Subcellular Localization of Iron during Embryo Development in Brassicaceae Seeds

PubMed Central

Ibeas, Miguel A.; Grant-Grant, Susana; Navarro, Nathalia; Perez, M. F.; Roschzttardtz, Hannetz

2017-01-01

Iron is an essential micronutrient for plants. Little is know about how iron is loaded in embryo during seed development. In this article we used Perls/DAB staining in order to reveal iron localization at the cellular and subcellular levels in different Brassicaceae seed species. In dry seeds of Brassica napus, Nasturtium officinale, Lepidium sativum, Camelina sativa, and Brassica oleracea iron localizes in vacuoles of cells surrounding provasculature in cotyledons and hypocotyl. Using B. napus and N. officinale as model plants we determined where iron localizes during seed development. Our results indicate that iron is not detectable by Perls/DAB staining in heart stage embryo cells. Interestingly, at torpedo development stage iron localizes in nuclei of different cells type, including integument, free cell endosperm and almost all embryo cells. Later, iron is detected in cytoplasmic structures in different embryo cell types. Our results indicate that iron accumulates in nuclei in specific stages of embryo maturation before to be localized in vacuoles of cells surrounding provasculature in mature seeds. PMID:29312417

The effect of MRN complex and ATM kinase inhibitors on Zebrafish embryonic development

NASA Astrophysics Data System (ADS)

Kumaran, Malina; Fazry, Shazrul

2018-04-01

Zebrafish is an ideal animal model to study developmental biology due to its transparent embryos and rapid development stages of embryogenesis. Here we investigate the role of DNA damage proteins, specifically Mre11/Rad50/NBN (MRN) complex and ataxia-telangiectasia mutated (ATM) kinase during embryogenesis by inhibiting its function using specific MRN complex (Mirin) and ATM Kinase inhibitors (Ku60019 and Ku55933). Zebrafish embryos at midblastula transition (MBT) stage are treated with Mirin, Ku60019 and Ku55933. The embryonic development of the embryos was monitored at 24 hours-post fertilisation (hpf), 48 hpf and 72 hpf. We observed that at the lowest concentrations (3 µM of Mirin, 1.5 nM of Ku60019 and 3 nM of Ku55933), the inhibitors treated embryos have 100% survivability. However, with increasing inhibitor concentration, the survivability drops. Control or mock treatment of all embryos shows 100 % survivability rate. This study suggests that DNA damage repair proteins may be crucial for normal zebrafish embryo development and survival.

Carbonic anhydrase activity in developing sea urchin embryos with special reference to calcification of spicules.

PubMed

Mitsunaga, K; Akasaka, K; Shimada, H; Fujino, Y; Yasumasu, I; Numanoi, H

1986-06-01

Eggs and embryos of the sea urchins Anthocidaris crassispina and Hemicentrotus pulcherrimus did not exhibit significant changes in carbonic anhydrase activity during early development. Acetazolamide inhibited enzyme activity in homogenates of embryos and inhibited the formation of calcified spicules in a culture of micromeres at concentrations between 40 and 100 microM. Acetazolamide allowed intact embryos to develop to quasi-normal plutei but inhibited calcium deposition in the spicules. It is suggested that carbonic anhydrase contributes to CaCO3 deposition in the spicule.

The ovine uterus as a host for in vitro-produced bovine embryos.

PubMed

Rexroad, C E; Powell, A M

1999-07-15

A series of experiments were conducted to determine whether bovine blastocysts would develop beyond the blastocyst stage in the ovine uterine environment. In Experiment 1, in vitro matured, fertilized and cultured (IVM/IVF/IVC) expanded bovine blastocysts were transferred into uteri of ewes on Day 7 or 9 of the estrous cycle and collected on Day 14 or 15 to determine if the bovine blastocysts would elongate and form an embryonic disk. Springtime trials with ewes that were synchronized with a medroxyprogesterone acetate (MAP) sponge resulted in a 78% blastocyst recovery rate, and 68% of the recovered spherical or elongated embryos had embryonic disks. In Experiment 2, transfer of 4-cell bovine embryos to the oviducts of ewes at Day 3 resulted in a lower recovery (47 vs 80%) than the transfer of blastocysts at Day 7 when embryos were recovered at Day 14. However, the percentage of embryos containing embryonic disks was higher for embryos transferred at the 4-cell stage (71%) than for embryos transferred as blastocysts (50%). In Experiment 3, IVF embryos from super-ovulated cows or Day 8 in vitro produced embryos transferred to cows were collected at Day 14 and were found to be similar in size to those produced by transfer to ewes in Experiment 2. In Experiment 4, the transfer of bovine blastocysts to ewes did not prolong the ovine estrous cycle. In Experiment 5, extension of the ovine estrous cycle by administration of a MAP releasing intravaginal device allowed bovine embryos to elongate extensively and to become filamentous. In Experiment 6, uterine flushings on Day 14 or Day 16 contained elevated levels of interferon-tau when bovine blastocyst were transferred on Day 7. Transfer of bovine embryos to the reproductive tract of a ewe allows some embryos to develop normally to advanced perimplantation stages and may be a useful tool for studying critical stages of embryo development and the developmental capacity of experimental embryos.

Early detection and staging of spontaneous embryo resorption by ultrasound biomicroscopy in murine pregnancy.

PubMed

Flores, Luis E; Hildebrandt, Thomas B; Kühl, Anja A; Drews, Barbara

2014-05-10

Embryo resorption is a major problem in human medicine, agricultural animal production and in conservation breeding programs. Underlying mechanisms have been investigated in the well characterised mouse model. However, post mortem studies are limited by the rapid disintegration of embryonic structures. A method to reliably identify embryo resorption in alive animals has not been established yet. In our study we aim to detect embryos undergoing resorption in vivo at the earliest possible stage by ultra-high frequency ultrasound. In a longitudinal study, we monitored 30 pregnancies of wild type C57BI/6 mice using ultra-high frequency ultrasound (30-70 MHz), so called ultrasound biomicroscopy (UBM). We compared the sonoembryology of mouse conceptuses under spontaneous resorption and neighbouring healthy conceptuses and correlated the live ultrasound data with the respective histology. The process of embryo resorption comprised of four stages: first, the conceptus exhibited growth retardation, second, bradycardia and pericardial edema were observed, third, further development ceased and the embryo died, and finally embryo remnants were resorbed by maternal immune cells. In early gestation (day 7 and 8), growth retardation was characterized by a small embryonic cavity. The embryo and its membranes were ill defined or did not develop at all. The echodensity of the embryonic fluid increased and within one to two days, the embryo and its cavity disappeared and was transformed into echodense tissue surrounded by fluid filled caverns. In corresponding histologic preparations, fibrinoid material interspersed with maternal granulocytes and lacunae filled with maternal blood were observed. In later stages (day 9-11) resorption prone embryos were one day behind in their development compared to their normal siblings. The space between Reichert's membrane and inner yolk sac membrane was enlarged The growth retarded embryos exhibited bradycardia and ultimately cessation of heart beat. Corresponding histology showed apoptotic cells in the embryo while the placenta was still intact. In the subsequent resorption process first the embryo and then its membranes disappeared. Our results provide a temporal time course of embryo resorption. With this method, animals exhibiting embryo resorption can be targeted, enabling the investigation of underlying mechanisms before the onset of total embryo disintegration.

Production of monozygotic twin calves using the blastomere separation technique and Well of the Well culture system.

PubMed

Tagawa, M; Matoba, S; Narita, M; Saito, N; Nagai, T; Imai, K

2008-03-15

The present study was conducted to establish a simple and efficient method of producing monozygotic twin calves using the blastomere separation technique. To produce monozygotic twin embryos from zona-free two- and eight-cell embryos, blastomeres were separated mechanically by pipetting to form two demi-embryos; each single blastomere from the two-cell embryo and tetra-blastomeres from the eight-cell embryo were cultured in vitro using the Well of the Well culture system (WOW). This culture system supported the successful arrangement of blastomeres, resulting in their subsequent aggregation to form a demi-embryo developing to the blastocyst stage without a zona pellucida. There was no significant difference in the development to the blastocyst stage between blastomeres separated from eight-cell (72.0%) and two-cell (62.0%) embryos. The production rates of the monozygotic pair blastocysts and transferable paired blastocysts for demi-embryos obtained from eight-cell embryos (64.0 and 45.0%, respectively) were higher than those for demi-embryos obtained from two-cell embryos (49.0 and 31.0%, P<0.05). The separated demi-embryos obtained from eight-cell embryos produced by IVM/IVF of oocytes collected by ovum pick-up (OPU) from elite cows and cultured in wells tended to have a higher pregnancy rate (78.9% vs. 57.1%) and similar monozygotic twinning rate (40.0% vs. 33.3%) compared with monozygotic twin blastocysts obtained by the conventional bisection of in vivo derived blastocysts. In conclusion, producing twins by separation of blastomeres in OPU-IVF embryos, followed by the WOW culture system, yielded viable monozygotic demi-embryos, resulting in high rates of pregnancy and twinning rates after embryo transfer.

Splitting of IVP bovine blastocyst affects morphology and gene expression of resulting demi-embryos during in vitro culture and in vivo elongation.

PubMed

Velasquez, Alejandra E; Castro, Fidel O; Veraguas, Daniel; Cox, Jose F; Lara, Evelyn; Briones, Mario; Rodriguez-Alvarez, Lleretny

2016-02-01

Embryo splitting might be used to increase offspring yield and for molecular analysis of embryo competence. How splitting affects developmental potential of embryos is unknown. This research aimed to study the effect of bovine blastocyst splitting on morphological and gene expression homogeneity of demi-embryos and on embryo competence during elongation. Grade I bovine blastocyst produced in vitro were split into halves and distributed in nine groups (3 × 3 setting according to age and stage before splitting; age: days 7-9; stage: early, expanded and hatched blastocysts). Homogeneity and survival rate in vitro after splitting (12 h, days 10 and 13) and the effect of splitting on embryo development at elongation after embryo transfer (day 17) were assessed morphologically and by RT-qPCR. The genes analysed were OCT4, SOX2, NANOG, CDX2, TP1, TKDP1, EOMES, and BAX. Approximately 90% of split embryos had a well conserved defined inner cell mass (ICM), 70% of the halves had similar size with no differences in gene expression 12 h after splitting. Split embryos cultured further conserved normal and comparable morphology at day 10 of development; this situation changes at day 13 when embryo morphology and gene expression differed markedly among demi-embryos. Split and non-split blastocysts were transferred to recipient cows and were recovered at day 17. Fifty per cent of non-split embryos were larger than 100 mm (33% for split embryos). OCT4, SOX2, TP1 and EOMES levels were down-regulated in elongated embryos derived from split blastocysts. In conclusion, splitting day-8 blastocysts yields homogenous demi-embryos in terms of developmental capability and gene expression, but the initiation of the filamentous stage seems to be affected by the splitting.

Promotion of human early embryonic development and blastocyst outgrowth in vitro using autocrine/paracrine growth factors.

PubMed

Kawamura, Kazuhiro; Chen, Yuan; Shu, Yimin; Cheng, Yuan; Qiao, Jie; Behr, Barry; Pera, Renee A Reijo; Hsueh, Aaron J W

2012-01-01

Studies using animal models demonstrated the importance of autocrine/paracrine factors secreted by preimplantation embryos and reproductive tracts for embryonic development and implantation. Although in vitro fertilization-embryo transfer (IVF-ET) is an established procedure, there is no evidence that present culture conditions are optimal for human early embryonic development. In this study, key polypeptide ligands known to be important for early embryonic development in animal models were tested for their ability to improve human early embryo development and blastocyst outgrowth in vitro. We confirmed the expression of key ligand/receptor pairs in cleavage embryos derived from discarded human tri-pronuclear zygotes and in human endometrium. Combined treatment with key embryonic growth factors (brain-derived neurotrophic factor, colony-stimulating factor, epidermal growth factor, granulocyte macrophage colony-stimulating factor, insulin-like growth factor-1, glial cell-line derived neurotrophic factor, and artemin) in serum-free media promoted >2.5-fold the development of tri-pronuclear zygotes to blastocysts. For normally fertilized embryos, day 3 surplus embryos cultured individually with the key growth factors showed >3-fold increases in the development of 6-8 cell stage embryos to blastocysts and >7-fold increase in the proportion of high quality blastocysts based on Gardner's criteria. Growth factor treatment also led to a 2-fold promotion of blastocyst outgrowth in vitro when day 7 surplus hatching blastocysts were used. When failed-to-be-fertilized oocytes were used to perform somatic cell nuclear transfer (SCNT) using fibroblasts as donor karyoplasts, inclusion of growth factors increased the progression of reconstructed SCNT embryos to >4-cell stage embryos. Growth factor supplementation of serum-free cultures could promote optimal early embryonic development and implantation in IVF-ET and SCNT procedures. This approach is valuable for infertility treatment and future derivation of patient-specific embryonic stem cells.

Glutamine supplementation enhances development of in vitro-produced porcine embryos and increases leucine consumption from the medium.

PubMed

Chen, Paula R; Redel, Bethany K; Spate, Lee D; Ji, Tieming; Salazar, Shirley Rojas; Prather, Randall S

2018-05-31

Improper composition of culture medium contributes to reduced viability of in vitro-produced embryos. Glutamine (Gln) is a crucial amino acid for preimplantation embryos as it supports proliferation and is involved in many different biosynthetic pathways. Previous transcriptional profiling revealed several upregulated genes related to Gln transport and metabolism in in vitro-produced porcine blastocysts compared to in vivo-produced counterparts, indicating a potential deficiency in the culture medium. Therefore, the objective of this study was to determine the effects of Gln supplementation on in vitro-produced porcine embryo development, gene expression, and metabolism. Cleaved embryos were selected and cultured in MU2 medium supplemented with 1 mM Gln (control), 3.75 mM Gln (+Gln), 3.75 mM GlutaMAX (+Max), or 3.75 mM alanine (+Ala) until day 6. Embryos cultured with +Gln or +Max had increased development to the blastocyst stage and total number of nuclei compared to the control (P < 0.05). Moreover, expression of misregulated transcripts involved in glutamine and glutamate transport and metabolism were corrected when embryos were cultured with +Gln or +Max. Metabolomics analysis revealed increased production of glutamine and glutamate into the medium by embryos cultured with +Max and increased consumption of leucine by embryos cultured with +Gln or +Max. As an indicator of cellular health, mitochondrial membrane potential was increased when embryos were cultured with +Max which was coincident with decreased apoptosis in these blastocysts. Lastly, two embryo transfers by using embryos cultured with +Max resulted in viable piglets, confirming that this treatment is consistent with in vivo developmental competence.

Allele-specific expression of the MAOA gene and X chromosome inactivation in in vitro produced bovine embryos.

PubMed

Ferreira, A R; Machado, G M; Diesel, T O; Carvalho, J O; Rumpf, R; Melo, E O; Dode, M A N; Franco, M M

2010-07-01

During embryogenesis, one of the two X chromosomes is inactivated in embryos. The production of embryos in vitro may affect epigenetic mechanisms that could alter the expression of genes related to embryo development and X chromosome inactivation (XCI). The aim of this study was to understand XCI during in vitro, pre-implantation bovine embryo development by characterizing the allele-specific expression pattern of the X chromosome-linked gene, monoamine oxidase A (MAOA). Two pools of ten embryos, comprised of the 4-, 8- to 16-cell, morula, blastocyst, and expanded blastocyst stages, were collected. Total RNA from embryos was isolated, and the RT-PCR-RFLP technique was used to observe expression of the MAOA gene. The DNA amplicons were also sequenced using the dideoxy sequencing method. MAOA mRNA was detected, and allele-specific expression was identified in each pool of embryos. We showed the presence of both the maternal and paternal alleles in the 4-, 8- to 16-cell, blastocyst and expanded blastocyst embryos, but only the maternal allele was present in the morula stage. Therefore, we can affirm that the paternal X chromosome is totally inactivated at the morula stage and reactivated at the blastocyst stage. To our knowledge, this is the first report of allele-specific expression of an X-linked gene that is subject to XCI in in vitro bovine embryos from the 4-cell to expanded blastocyst stages. We have established a pattern of XCI in our in vitro embryo production system that can be useful as a marker to assist the development of new protocols for in vitro embryo production. (c) 2010 Wiley-Liss, Inc.

Natural Selection of Human Embryos: Decidualizing Endometrial Stromal Cells Serve as Sensors of Embryo Quality upon Implantation

PubMed Central

Teklenburg, Gijs; Salker, Madhuri; Molokhia, Mariam; Lavery, Stuart; Trew, Geoffrey; Aojanepong, Tepchongchit; Mardon, Helen J.; Lokugamage, Amali U.; Rai, Raj; Landles, Christian; Roelen, Bernard A. J.; Quenby, Siobhan; Kuijk, Ewart W.; Kavelaars, Annemieke; Heijnen, Cobi J.; Regan, Lesley; Brosens, Jan J.; Macklon, Nick S.

2010-01-01

Background Pregnancy is widely viewed as dependent upon an intimate dialogue, mediated by locally secreted factors between a developmentally competent embryo and a receptive endometrium. Reproductive success in humans is however limited, largely because of the high prevalence of chromosomally abnormal preimplantation embryos. Moreover, the transient period of endometrial receptivity in humans uniquely coincides with differentiation of endometrial stromal cells (ESCs) into highly specialized decidual cells, which in the absence of pregnancy invariably triggers menstruation. The role of cyclic decidualization of the endometrium in the implantation process and the nature of the decidual cytokines and growth factors that mediate the crosstalk with the embryo are unknown. Methodology/Principal Findings We employed a human co-culture model, consisting of decidualizing ESCs and single hatched blastocysts, to identify the soluble factors involved in implantation. Over the 3-day co-culture period, approximately 75% of embryos arrested whereas the remainder showed normal development. The levels of 14 implantation factors secreted by the stromal cells were determined by multiplex immunoassay. Surprisingly, the presence of a developing embryo had no significant effect on decidual secretions, apart from a modest reduction in IL-5 levels. In contrast, arresting embryos triggered a strong response, characterized by selective inhibition of IL-1β, -6, -10, -17, -18, eotaxin, and HB-EGF secretion. Co-cultures were repeated with undifferentiated ESCs but none of the secreted cytokines were affected by the presence of a developing or arresting embryo. Conclusions Human ESCs become biosensors of embryo quality upon differentiation into decidual cells. In view of the high incidence of gross chromosomal errors in human preimplantation embryos, cyclic decidualization followed by menstrual shedding may represent a mechanism of natural embryo selection that limits maternal investment in developmentally impaired pregnancies. PMID:20422011

Improved embryo development in Japanese black cattle by in vitro fertilization using ovum pick-up plus intracytoplasmic sperm injection with dithiothreitol.

PubMed

Oikawa, Toshinori; Itahashi, Tomoko; Numabe, Takashi

2016-01-01

The purpose of this study was to determine whether dithiothreitol (DTT) treatment of sperm and ethanol activation improve embryo production by intracytoplasmic sperm injection (ICSI). Further, we compared ICSI with standard in vitro fertilization (IVF) in oocytes obtained from cattle. We demonstrated that DTT reduced the disulfide bond in the bovine sperm head. Using oocytes obtained from a slaughterhouse, ICSI-DTT treatment without ethanol showed the highest rate of blastocyst formation. We applied these results to fertilization using ovum pick-up (OPU). Eleven Japanese black cattle served as donors for OPU plus standard IVF (OPU-IVF). Of them, four donors with low embryo development rates were selected to determine whether embryo development was enhanced by OPU plus ICSI (OPU-ICSI). We assessed effects on embryo development following IVF and ICSI in oocytes obtained using OPU. Blastocyst rates were significantly higher for OPU-ICSI than for OPU-IVF. Our results suggest that OPU-ICSI improves the blastocyst development rate in donors with low embryo production compared with the standard OPU-IVF.

Improved embryo development in Japanese black cattle by in vitro fertilization using ovum pick-up plus intracytoplasmic sperm injection with dithiothreitol

PubMed Central

OIKAWA, Toshinori; ITAHASHI, Tomoko; NUMABE, Takashi

2015-01-01

The purpose of this study was to determine whether dithiothreitol (DTT) treatment of sperm and ethanol activation improve embryo production by intracytoplasmic sperm injection (ICSI). Further, we compared ICSI with standard in vitro fertilization (IVF) in oocytes obtained from cattle. We demonstrated that DTT reduced the disulfide bond in the bovine sperm head. Using oocytes obtained from a slaughterhouse, ICSI-DTT treatment without ethanol showed the highest rate of blastocyst formation. We applied these results to fertilization using ovum pick-up (OPU). Eleven Japanese black cattle served as donors for OPU plus standard IVF (OPU-IVF). Of them, four donors with low embryo development rates were selected to determine whether embryo development was enhanced by OPU plus ICSI (OPU-ICSI). We assessed effects on embryo development following IVF and ICSI in oocytes obtained using OPU. Blastocyst rates were significantly higher for OPU-ICSI than for OPU-IVF. Our results suggest that OPU-ICSI improves the blastocyst development rate in donors with low embryo production compared with the standard OPU-IVF. PMID:26460690

Transcriptomic analysis highlights epigenetic and transcriptional regulation during zygotic embryo development of Pinus pinaster.

PubMed

de Vega-Bartol, José J; Simões, Marta; Lorenz, W Walter; Rodrigues, Andreia S; Alba, Rob; Dean, Jeffrey F D; Miguel, Célia M

2013-08-30

It is during embryogenesis that the plant body plan is established and the meristems responsible for all post-embryonic growth are specified. The molecular mechanisms governing conifer embryogenesis are still largely unknown. Their elucidation may contribute valuable information to clarify if the distinct features of embryo development in angiosperms and gymnosperms result from differential gene regulation. To address this issue, we have performed the first transcriptomic analysis of zygotic embryo development in a conifer species (Pinus pinaster) focusing our study in particular on regulatory genes playing important roles during plant embryo development, namely epigenetic regulators and transcription factors. Microarray analysis of P. pinaster zygotic embryogenesis was performed at five periods of embryo development from early developing to mature embryos. Our results show that most changes in transcript levels occurred in the first and the last embryo stage-to-stage transitions, namely early to pre-cotyledonary embryo and cotyledonary to mature embryo. An analysis of functional categories for genes that were differentially expressed through embryogenesis highlighted several epigenetic regulation mechanisms. While putative orthologs of transcripts associated with mechanisms that target transposable elements and repetitive sequences were strongly expressed in early embryogenesis, PRC2-mediated repression of genes seemed more relevant during late embryogenesis. On the other hand, functions related to sRNA pathways appeared differentially regulated across all stages of embryo development with a prevalence of miRNA functions in mid to late embryogenesis. Identification of putative transcription factor genes differentially regulated between consecutive embryo stages was strongly suggestive of the relevance of auxin responses and regulation of auxin carriers during early embryogenesis. Such responses could be involved in establishing embryo patterning. Later in development, transcripts with homology to genes acting on modulation of auxin flow and determination of adaxial-abaxial polarity were up-regulated, as were putative orthologs of genes required for meristem formation and function as well as establishment of organ boundaries. Comparative analysis with A. thaliana embryogenesis also highlighted genes involved in auxin-mediated responses, as well as epigenetic regulation, indicating highly correlated transcript profiles between the two species. This is the first report of a time-course transcriptomic analysis of zygotic embryogenesis in a conifer. Taken together our results show that epigenetic regulation and transcriptional control related to auxin transport and response are critical during early to mid stages of pine embryogenesis and that important events during embryogenesis seem to be coordinated by putative orthologs of major developmental regulators in angiosperms.

Transcriptomic analysis highlights epigenetic and transcriptional regulation during zygotic embryo development of Pinus pinaster

PubMed Central

2013-01-01

Background It is during embryogenesis that the plant body plan is established and the meristems responsible for all post-embryonic growth are specified. The molecular mechanisms governing conifer embryogenesis are still largely unknown. Their elucidation may contribute valuable information to clarify if the distinct features of embryo development in angiosperms and gymnosperms result from differential gene regulation. To address this issue, we have performed the first transcriptomic analysis of zygotic embryo development in a conifer species (Pinus pinaster) focusing our study in particular on regulatory genes playing important roles during plant embryo development, namely epigenetic regulators and transcription factors. Results Microarray analysis of P. pinaster zygotic embryogenesis was performed at five periods of embryo development from early developing to mature embryos. Our results show that most changes in transcript levels occurred in the first and the last embryo stage-to-stage transitions, namely early to pre-cotyledonary embryo and cotyledonary to mature embryo. An analysis of functional categories for genes that were differentially expressed through embryogenesis highlighted several epigenetic regulation mechanisms. While putative orthologs of transcripts associated with mechanisms that target transposable elements and repetitive sequences were strongly expressed in early embryogenesis, PRC2-mediated repression of genes seemed more relevant during late embryogenesis. On the other hand, functions related to sRNA pathways appeared differentially regulated across all stages of embryo development with a prevalence of miRNA functions in mid to late embryogenesis. Identification of putative transcription factor genes differentially regulated between consecutive embryo stages was strongly suggestive of the relevance of auxin responses and regulation of auxin carriers during early embryogenesis. Such responses could be involved in establishing embryo patterning. Later in development, transcripts with homology to genes acting on modulation of auxin flow and determination of adaxial-abaxial polarity were up-regulated, as were putative orthologs of genes required for meristem formation and function as well as establishment of organ boundaries. Comparative analysis with A. thaliana embryogenesis also highlighted genes involved in auxin-mediated responses, as well as epigenetic regulation, indicating highly correlated transcript profiles between the two species. Conclusions This is the first report of a time-course transcriptomic analysis of zygotic embryogenesis in a conifer. Taken together our results show that epigenetic regulation and transcriptional control related to auxin transport and response are critical during early to mid stages of pine embryogenesis and that important events during embryogenesis seem to be coordinated by putative orthologs of major developmental regulators in angiosperms. PMID:23987738

Chapter 1 Historical Background on Gamete and Embryo Cryopreservation.

PubMed

Ali, Jaffar; AlHarbi, Naif H; Ali, Nafisa

2017-01-01

This chapter describes the development of the science of cryopreservation of gametes and embryos of various species including human. It attempts to record in brief the main contributions of workers in their attempts to cryopreserve gametes and embryos. The initial difficulties faced and subsequent developments and triumphs leading to present-day state of the art are given in a concise manner. The main players and their contributions are mentioned and the authors' aim is to do justice to them. This work also attempts to ensure that credit is correctly attributed for significant advances in gamete and embryo cryopreservation. In general this chapter has tried to describe the historical development of the science of cryopreservation of gametes and embryos as accurately as possible without bias or partiality.

In vitro development of canine somatic cell nuclear transfer embryos in different culture media.

PubMed

Kim, Dong-Hoon; No, Jin-Gu; Choi, Mi-Kyung; Yeom, Dong-Hyeon; Kim, Dong-Kyo; Yang, Byoung-Chul; Yoo, Jae Gyu; Kim, Min Kyu; Kim, Hong-Tea

2015-01-01

The objective of the present study was to investigate the effects of three different culture media on the development of canine somatic cell nuclear transfer (SCNT) embryos. Canine cloned embryos were cultured in modified synthetic oviductal fluid (mSOF), porcine zygote medium-3 (PZM-3), or G1/G2 sequential media. Our results showed that the G1/G2 media yielded significantly higher morula and blastocyst development in canine SCNT embryos (26.1% and 7.8%, respectively) compared to PZM-3 (8.5% and 0%or mSOF (2.3% and 0%) media. In conclusion, this study suggests that blastocysts can be produced more efficiently using G1/G2 media to culture canine SCNT embryos.

Persons and their bodies: how we should think about human embryos.

PubMed

McLachlan, Hugh V

2002-01-01

The status of human embryos is discussed particularly in the light of the claim by Fox, in Health Care Analysis 8 that it would be useful to think of them in terms of cyborg metaphors. It is argued that we should consider human embryos for what they are--partially formed human bodies--rather than for what they are like in some respects (and unlike in others)--cyborgs. However to settle the issue of the status of the embryo is not to answer the moral questions which arise concerning how embryos should be treated. Since persons rather than bodies have rights, embryos do not have rights. However, whether or not embryos have rights, people can have duties concerning them. Furthermore, the persons whose fully developed bodies embryos will, might (or might have) become can have rights. Contrary to what is often assumed, it is not merely persons who have (or have had) living, developed human bodies who have moral rights: so it is argued in this paper.

In vitro culture of individual mouse preimplantation embryos: the role of embryo density, microwells, oxygen, timing and conditioned media.

PubMed

Kelley, Rebecca L; Gardner, David K

2017-05-01

Single embryo culture is suboptimal compared with group culture, but necessary for embryo monitoring, and culture systems should be improved for single embryos. Pronucleate mouse embryos were used to assess the effect of culture conditions on single embryo development. Single culture either before or after compaction reduced cell numbers (112.2 ± 3.1; 110.2 ± 3.5) compared with group culture throughout (127.0 ± 3.4; P < 0.05). Reduction of media volume from 20 µl to 2 µl increased blastocyst cell numbers in single embryos cultured in 5% oxygen (84.4 ± 3.2 versus 97.8 ± 2.8; P < 0.05), but not in 20% oxygen (55.2 ± 2.9 versus 57.1 ± 2.8). Culture in microwell plates for the EmbryoScope and Primo Vision time-lapse systems changed cleavage timings and increased inner cell mass cell number (24.1 ± 1.0; 23.4 ± 1.2) compared with a 2 µl microdrop (18.4 ± 1.0; P < 0.05). Addition of embryo-conditioned media to single embryos increased hatching rate and blastocyst cell number (91.5 ± 4.7 versus 113.1 ± 4.4; P < 0.01). Single culture before or after compaction is therefore detrimental; oxygen, media volume and microwells influence single embryo development; and embryo-conditioned media may substitute for group culture. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Positioning Tool Validation Report

DTIC Science & Technology

1999-11-01

U.S. Coast Guard Research and Development Center 1082 Shennecossett Road, Groton, CT 06340-6096 Report No. CG-D-06-00 Positioning Tool...standard, specification, or regulation. Marc B. Mandler, Ph.D. Technical Director United States Coast Guard Research & Development Center 1082 ...Validation Report 7. Author(s) Jay Spalding i. Performing Organization Name and Address U.S. Coast Guard Research and Development Center 1082

Shoreside Alternative Energy Evaluation

DTIC Science & Technology

2002-09-01

U.S. Coast Guard Research and Development Center 1082 Shennecossett Road, Groton, CT 06340-6096 Report No. CG-D-02-02 SHORESIDE ALTERNATIVE ENERGY...standard, specification, or regulation. Marc B. Mandler, Ph.D. Technical Director United States Coast Guard Research & Development Center 1082 ...Coast Guard Research and Development Center 1082 Shennecossett Road Groton, CT 06340-6096 10. Work Unit No. (TRAIS) 11. Contract or Grant No. 12

A temporary immersion system improves in vitro regeneration of peach palm through secondary somatic embryogenesis

PubMed Central

Steinmacher, D. A.; Guerra, M. P.; Saare-Surminski, K.; Lieberei, R.

2011-01-01

Background and Aims Secondary somatic embryogenesis has been postulated to occur during induction of peach palm somatic embryogenesis. In the present study this morphogenetic pathway is described and a protocol for the establishment of cycling cultures using a temporary immersion system (TIS) is presented. Methods Zygotic embryos were used as explants, and induction of somatic embryogenesis and plantlet growth were compared in TIS and solid culture medium. Light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to describe in vitro morphogenesis and accompany morpho-histological alterations during culture. Key Results The development of secondary somatic embryos occurs early during the induction of primary somatic embryos. Secondary somatic embryos were observed to develop continually in culture, resulting in non-synchronized development of these somatic embryos. Using these somatic embryos as explants allowed development of cycling cultures. Somatic embryos had high embryogenic potential (65·8 ± 3·0 to 86·2 ± 5·0 %) over the period tested. The use of a TIS greatly improved the number of somatic embryos obtained, as well as subsequent plantlet growth. Histological analyses showed that starch accumulation precedes the development of somatic embryos, and that these cells presented high nucleus/cytoplasm ratios and high mitotic indices, as evidenced by DAPI staining. Morphological and SEM observations revealed clusters of somatic embryos on one part of the explants, while other parts grew further, resulting in callus tissue. A multicellular origin of the secondary somatic embryos is hypothesized. Cells in the vicinity of callus accumulated large amounts of phenolic substances in their vacuoles. TEM revealed that these cells are metabolically very active, with the presence of numerous mitochondria and Golgi apparatuses. Light microscopy and TEM of the embryogenic sector revealed cells with numerous amyloplasts, large nuclei and nucleoli, and numerous plasmodesmata. Plantlets were obtained and after 3 months in culture their growth was significantly better in TIS than on solid culture medium. However, during acclimatization the survival rate of TIS-grown plantlets was lower. Conclusions The present study confirms the occurrence of secondary somatic embryos in peach palm and describes a feasible protocol for regeneration of peach palm in vitro. Further optimizations include the use of explants obtained from adult palms and improvement of somatic embryo conversion rates. PMID:21355009

Pattern of Variations in Abscisic Acid Content in Suspensors, Embryos, and Integuments of Developing Phaseolus coccineus Seeds 1

PubMed Central

Perata, Pierdomenico; Picciarelli, Piero; Alpi, Amedeo

1990-01-01

Free abscisic acid (ABA) content in suspensors, embryos, and integuments was determined during seed development of Phaseolus coccineus. A highly specific and sensitive solid-phase radioimmunoassay based on a monocional antibody raised against free (S)-ABA was used for ABA quantification. Very small amounts of ABA were detected in the suspensor during initial stages of development; later two peaks of ABA occurred. Levels of ABA in the embryo and integument show a coincident triphasic distribution: two maxima in ABA content occurred when the embryo was 11 to 12 and 15 to 16 millimeters in length; later, when the embryo was 19 to 20 millimeters long, a further increase was observed. The role of ABA in runner bean seeds is discussed in relation to the development of the different seed tissues. PMID:16667915

Limiting factors to encapsulation: the combined effects of dissolved protein and oxygen availability on embryonic growth and survival of species with contrasting feeding strategies.

PubMed

Brante, Antonio; Fernández, Miriam; Viard, Frédérique

2009-07-01

Encapsulation is a common strategy among marine invertebrate species. It has been shown that oxygen and food availability independently constrain embryo development during intracapsular development. However, it is unclear how embryos of species with different feeding strategies perceive these two constraints when operating jointly. In the present study, we examined the relative importance of dissolved albumen, as a food source, oxygen condition and their interaction on embryonic growth and the survival of two calyptraeid species, Crepidula coquimbensis and Crepidula fornicata, exhibiting different embryo feeding behaviours (i.e. presence vs absence of intracapsular cannibalism). Two oxygen condition treatments (normoxia and hypoxia) and three albumen concentrations (0, 1 and 2 mg l(-1)) were studied. In addition, albumen intake by embryos was observed using fluorescence microscopy. Our study shows that embryos of both species incorporated dissolved albumen but used a different set of embryonic organs. We observed that embryo growth rates in C. coquimbensis were negatively affected only by hypoxic conditions. Conversely, a combination of low albumen concentration and oxygen availability slowed embryo growth in C. fornicata. These findings suggest that oxygen availability is a limiting factor for the normal embryo development of encapsulated gastropod species, regardless of feeding behaviour or developmental mode. By contrast, the effect of dissolved albumen as an alternative food source on embryo performance may depend on the feeding strategy of the embryos.

Media composition: growth factors.

PubMed

Hegde, Aparna; Behr, Barry

2012-01-01

Despite the fact that the fundamental principle underlying the most common method of culture media constitution is that of mimicking the natural environment of the preimplantation embryo, one major difference that remains between current embryo culture media and in vivo conditions is the absence of growth factors in vitro. Numerous growth factors are known to be present in the in vivo environment of human and nonhuman preimplantation embryos, often with peak concentrations corresponding to when fertilization and preimplantation embryo growth would occur. Although these growth factors are found in very small concentrations, they have a profound effect on tissue growth and differentiation through attachment to factor-specific receptors on cell surfaces. Receptors for many different growth factors have also been detected in human preimplantation embryos. Preimplantation embryos themselves express many growth factors. The growth factors and receptors are metabolically costly to produce, and thus their presence in the environment of the preimplantation embryo and in the embryo respectively strongly implies that embryos are designed to encounter and respond to the corresponding factors. Studies of embryo coculture also indirectly suggest that growth factors can improve in vitro development. Several animal and human studies attest to a probable beneficial effect of addition of growth factors to culture media. However, there is still ambiguity regarding the exact role of growth factors in embryonic development, the optimal dose of growth factors to be added to culture media, the combinatorial effect and endocrine of growth factors in embryonic development.

Ice nucleating agents allow embryo freezing without manual seeding.

PubMed

Teixeira, Magda; Buff, Samuel; Desnos, Hugo; Loiseau, Céline; Bruyère, Pierre; Joly, Thierry; Commin, Loris

2017-12-01

Embryo slow freezing protocols include a nucleation induction step called manual seeding. This step is time consuming, manipulator dependent and hard to standardize. It requires access to samples, which is not always possible within the configuration of systems, such as differential scanning calorimeters or cryomicroscopes. Ice nucleation can be induced by other methods, e.g., by the use of ice nucleating agents. Snomax is a commercial preparation of inactivated proteins extracted from Pseudomonas syringae. The aim of our study was to investigate if Snomax can be an alternative to manual seeding in the slow freezing of mouse embryos. The influence of Snomax on the pH and osmolality of the freezing medium was evaluated. In vitro development (blastocyst formation and hatching rates) of fresh embryos exposed to Snomax and embryo cryopreserved with and without Snomax was assessed. The mitochondrial activity of frozen-thawed blastocysts was assessed by JC-1 fluorescent staining. Snomax didn't alter the physicochemical properties of the freezing medium, and did not affect embryo development of fresh embryos. After cryopreservation, the substitution of manual seeding by the ice nucleating agent (INA) Snomax did not affect embryo development or embryo mitochondrial activity. In conclusion, Snomax seems to be an effective ice nucleating agent for the slow freezing of mouse embryos. Snomax can also be a valuable alternative to manual seeding in research protocols in which manual seeding cannot be performed (i.e., differential scanning calorimetry and cryomicroscopy). Copyright © 2017 Elsevier Inc. All rights reserved.

In vitro survival of fresh and frozen/thawed bovine demi-embryos.

PubMed

Lucas-Hahn, A; Niemann, H

1991-10-01

Three experiments were conducted to investigate the effects of type of culture medium in freshly bisected bovine embryos and the effects of agar embedding and of 1.2 propanediol (PROH) as the cryoprotectant in frozen/thawed bisected bovine embryos on development in vitro. A total of 265 bovine embryos were used as controls or were microsurgically bisected and were cultured in vitro for 48 hours and development was determined 24 and 48 hours after the onset of culture. Whitten's medium supported more (P<0.05) intact and demi-embryos to grow to expanded blastocysts (92.9 and 73.1%, respectively) compared with Ham's F10 (43.8 and 26.3%, respectively) and PBS (53.8 and 12.5%, respectively). Embedding in agar and culture in Whitten's medium resulted in a higher (P<0.05) percentage of in vitro development of frozen/thawed demi-embryos after 24 hours than the freezing of nonembedded demi-embryos (44.1 versus 19.6%, respectively). This difference disappeared, however, after a 48 hours culture period (17.6 versus 11.8%, respectively). Following freezing in PROH, survival rates of 40 and 28%, respectively after 24 hours of culture were obtained for intact and demi-embryos. The respective percentages after 48 hours were 8.6 and 16%. Since neither embedding in agar nor the use of PROH as the cryoprotectant resulted in high survival rates of frozen/thawed demi-embryos in vitro, new freezing procedures are needed to overcome the sensitivity of demi-embryos to freezing and thawing.

Are there symplastic connections between the endosperm and embryo in some angiosperms?--a lesson from the Crassulaceae family.

PubMed

Kozieradzka-Kiszkurno, Małgorzata; Płachno, Bartosz Jan

2012-10-01

It is believed that there is symplastic isolation between the embryo (new sporophyte) and the endosperm (maternal-parental origin tissue, which nourishes the embryo) in angiosperms. However, in embryological literature there are rare examples in which plasmodesmata between the embryo suspensor and endosperm cells have been recorded (three species from Fabaceae). This study was undertaken in order to test the hypothesis that plasmodesmata between the embryo suspensor and the endosperm are not so rare but also occur in other angiosperm families; in order to check this, we used the Crassulaceae family because embryogenesis in Crassulaceae has been studied extensively at an ultrastructure level recently and also we tread members of this family as model for suspensor physiology and function studies. These plasmodesmata even occurred between the basal cell of the two-celled proembryo and endosperm cells. The plasmodesmata were simple at this stage of development. During the development of the embryo proper and the suspensor, the structure of plasmodesmata changes. They were branched and connected with electron-dense material. Our results suggest that in Crassulaceae with plasmodesmata between the endosperm and suspensor, symplastic connectivity at this cell-cell boundary is still reduced or blocked at a very early stage of embryo development (before the globular stage). The occurrence of plasmodesmata between the embryo suspensor and endosperm cells suggests possible symplastic transport between these different organs, at least at a very early stage of embryo development. However, whether this transport actually occurs needs to be proven experimentally. A broader analysis of plants from various families would show whether the occurrence of plasmodesmata between the embryo suspensor and the endosperm are typical embryological characteristics and if this is useful in discussions about angiosperm systematic and evolution.

Using game theory to investigate the epigenetic control mechanisms of embryo development: Comment on: "Epigenetic game theory: How to compute the epigenetic control of maternal-to-zygotic transition" by Qian Wang et al.

PubMed

Zhang, Le; Zhang, Shaoxiang

2017-03-01

A body of research [1-7] has already shown that epigenetic reprogramming plays a critical role in maintaining the normal development of embryos. However, the mechanistic quantitation of the epigenetic interactions between sperms and oocytes and the related impact on embryo development are still not clear [6,7]. In this study, Wang et al., [8] develop a modeling framework that addresses this question by integrating game theory and the latest discoveries of the epigenetic control of embryo development. Copyright © 2017 Elsevier B.V. All rights reserved.

Dissection of culture media for embryos: the most important and less important components and characteristics.

PubMed

Gardner, David K

2008-01-01

Improvements in culture media formulations have led to an increase in the ability to maintain the mammalian embryo in culture throughout the preimplantation and pre-attachment period. Amino acids and specific macromolecules have been identified as being key medium components, whereas temporal dynamics have been recognised as important media characteristics. Furthermore, other laboratory factors that directly impact embryo development and viability have been identified. Such factors include the use of a reduced oxygen tension, an appropriate incubation system and an adequate prescreening of all contact supplies. With rigourous quality systems in place, it is possible to obtain in vivo rates of embryo development in vitro using new media formulations while maintaining high levels of embryo viability. The future of embryo culture will likely be based on novel culture chips capable of providing temporal dynamics while facilitating real-time analysis of embryo physiology.

Endometrium as an early sensor of in vitro embryo manipulation technologies

PubMed Central

Mansouri-Attia, Nadéra; Sandra, Olivier; Aubert, Julie; Degrelle, Séverine; Everts, Robin E.; Giraud-Delville, Corinne; Heyman, Yvan; Galio, Laurent; Hue, Isabelle; Yang, Xiangzhong; Tian, X. Cindy; Lewin, Harris A.; Renard, Jean-Paul

2009-01-01

Implantation is crucial for placental development that will subsequently impact fetal growth and pregnancy success with consequences on postnatal health. We postulated that the pattern of genes expressed by the endometrium when the embryo becomes attached to the mother uterus could account for the final outcome of a pregnancy. As a model, we used the bovine species where the embryo becomes progressively and permanently attached to the endometrium from day 20 of gestation onwards. At that stage, we compared the endometrial genes profiles in the presence of an in vivo fertilized embryo (AI) with the endometrial patterns obtained in the presence of nuclear transfer (SCNT) or in vitro fertilized embryos (IVF), both displaying lower and different potentials for term development. Our data provide evidence that the endometrium can be considered as a biological sensor able to fine-tune its physiology in response to the presence of embryos whose development will become altered much later after the implantation process. Compared with AI, numerous biological functions and several canonical pathways with a major impact on metabolism and immune function were found to be significantly altered in the endometrium of SCNT pregnancies at implantation, whereas the differences were less pronounced with IVF embryos. Determining the limits of the endometrial plasticity at the onset of implantation should bring new insights on the contribution of the maternal environment to the development of an embryo and the success of pregnancy. PMID:19297625

Identification and characterization of an oocyte factor required for development of porcine nuclear transfer embryos

PubMed Central

Miyamoto, Kei; Nagai, Kouhei; Kitamura, Naoya; Nishikawa, Tomoaki; Ikegami, Haruka; Binh, Nguyen T.; Tsukamoto, Satoshi; Matsumoto, Mai; Tsukiyama, Tomoyuki; Minami, Naojiro; Yamada, Masayasu; Ariga, Hiroyoshi; Miyake, Masashi; Kawarasaki, Tatsuo; Matsumoto, Kazuya; Imai, Hiroshi

2011-01-01

Nuclear reprogramming of differentiated cells can be induced by oocyte factors. Despite numerous attempts, these factors and mechanisms responsible for successful reprogramming remain elusive. Here, we identify one such factor, necessary for the development of nuclear transfer embryos, using porcine oocyte extracts in which some reprogramming events are recapitulated. After incubating somatic nuclei in oocyte extracts from the metaphase II stage, the oocyte proteins that were specifically and abundantly incorporated into the nuclei were identified by mass spectrometry. Among 25 identified proteins, we especially focused on a multifunctional protein, DJ-1. DJ-1 is present at a high concentration in oocytes from the germinal vesicle stage until embryos at the four-cell stage. Inhibition of DJ-1 function compromises the development of nuclear transfer embryos but not that of fertilized embryos. Microarray analysis of nuclear transfer embryos in which DJ-1 function is inhibited shows perturbed expression of P53 pathway components. In addition, embryonic arrest of nuclear transfer embryos injected with anti–DJ-1 antibody is rescued by P53 inhibition. We conclude that DJ-1 is an oocyte factor that is required for development of nuclear transfer embryos. This study presents a means for identifying natural reprogramming factors in mammalian oocytes and a unique insight into the mechanisms underlying reprogramming by nuclear transfer. PMID:21482765

Normal calves produced after transfer of embryos cultured in a chemically defined medium supplemented with epidermal growth factor and insulin-like growth factor I following ovum pick up and in vitro fertilization in Japanese black cows.

PubMed

Sakagami, Nobutada; Umeki, Hidenobu; Nishino, Osamu; Uchiyama, Hiroko; Ichikawa, Kyoko; Takeshita, Kazuhisa; Kaneko, Etsushi; Akiyama, Kiyoshi; Kobayashi, Shuji; Tamada, Hiromichi

2012-01-01

The objective of this study was to examine whether high concentrations of epidermal growth factor (EGF) and/or insulin-like growth factor I (IGF-I) would have a beneficial effect on bovine embryo development in vitro and to obtain normal calves by using an ovum pick up method and embryo culture in a chemically defined medium. When compared with controls, EGF (100 or 200 ng/ml) or IGF-I (50 or 100 ng/ml) significantly increased the rate of embryos that developed into blastocysts during an 8-day culture after the in vitro fertilization of oocytes obtained from ovaries from a slaughterhouse. IGF-I induced a dose-dependent increase in cell number in both the inner cell mass and the trophectoderm, whereas EGF stimulated proliferation only in the inner cell mass. A combination of EGF (100 ng/ml) and IGF-I (50 ng/ml) produced an additive effect, and embryos developed into blastocysts at a comparatively high rate (27.9%) compared with controls (12.0%). A similar rate of development was achieved using a combination of EGF and IGF-I in the culture of embryos following ovum pick up by ultrasound-guided transvaginal follicular aspiration and in vitro fertilization, and 5 blastocysts that developed after the culture were transferred into uteri; two embryos implanted, and normal calves were born. These results suggest that the combined use of EGF and IGF-I makes bovine embryo culture in a chemically defined medium a practical and useful procedure for producing blastocysts, and its application to embryo culture following ovum pick up and in vitro fertilization could be useful for producing normal calves.

Pleurodeles waltl, amphibian, Urodele, is a suitable biological model for embryological and physiological space experiments on a vertebrate

NASA Astrophysics Data System (ADS)

Gualandris-Parisot, L.; Husson, D.; Foulquier, F.; Kan, P.; Davet, J.; Aimar, C.; Dournon, C.; Duprat, A. M.

2001-01-01

Pleurodeles waltl (amphibian, Urodele) is an appropriate biological model for space experiments on a vertebrate. One reason for interest in this animal concerns the study of the effects of absence of gravity on embryonic development. First, after mating (on Earth) the females retain live, functional sperm in their cloacum for up to 5 months, allowing normal in vivo fertilisation after hormonal stimulation. Second, their development is slow, which allows analyses of all the key stages of ontogenesis from the oocyte to swimming tailbud embryos or larvae. We have performed detailed studies and analyses of the effects of weightlessness on amphibian Pleurodeles embryos, fertilised and allowed to develop until the swimming larvae stage. These experiments were performed in space during three missions on the MIR-station: FERTILE I, FERTILE II and NEUROGENESIS respectively in 1996, 1998 and 1999. We show that in microgravity abnormalities appeared at specific stages of development compared to 1g-centrifuge control embryos and 1g-ground control embryos. In this report we describe abnormalities occurring in the central nervous system. These modifications occur during the neurulation process (delay in the closure of the neural tube and failure of closure of this tube in the cephalic area) and at the early tailbud stage (microcephaly observed in 40% of the microgravity-embryos). However, if acephalic and microcephalic embryos are not taken into account, these abnormalities did not disturb further morphological, biochemical and functional development and the embryos were able to regulate and a majority of normal hatching and swimming larvae were obtained in weightlessness with a developmental time-course equivalent to that of 1g-centrifuge control embryos (on the MIR station) and 1g-ground control embryos.

Combinatorial effects of zinc deficiency and arsenic exposure on zebrafish (Danio rerio) development

PubMed Central

Truong, Lisa; Barton, Carrie L.; Chase, Tyler T.; Gonnerman, Greg D.; Wong, Carmen P.; Tanguay, Robert L.; Ho, Emily

2017-01-01

Zinc deficiency and chronic low level exposures to inorganic arsenic in drinking water are both significant public health concerns that affect millions of people including pregnant women. These two conditions can co-exist in the human population but little is known about their interaction, and in particular, whether zinc deficiency sensitizes individuals to arsenic exposure and toxicity, especially during critical windows of development. To address this, we utilized the Danio rerio (zebrafish) model to test the hypothesis that parental zinc deficiency sensitizes the developing embryo to low-concentration arsenic toxicity, leading to altered developmental outcomes. Adult zebrafish were fed defined zinc deficient and zinc adequate diets and were spawned resulting in zinc adequate and zinc deficient embryos. The embryos were treated with environmentally relevant concentrations of 0, 50, and 500 ppb arsenic. Arsenic exposure significantly reduced the amount of zinc in the developing embryo by ~7%. The combination of zinc deficiency and low-level arsenic exposures did not sensitize the developing embryo to increased developmental malformations or mortality. The combination did cause a 40% decline in physical activity of the embryos, and this decline was significantly greater than what was observed with zinc deficiency or arsenic exposure alone. Significant changes in RNA expression of genes that regulate zinc homeostasis, response to oxidative stress and insulin production (including zip1, znt7, nrf2, ogg1, pax4, and insa) were found in zinc deficient, or zinc deficiency and arsenic exposed embryos. Overall, the data suggests that the combination of zinc deficiency and arsenic exposure has harmful effects on the developing embryo and may increase the risk for developing chronic diseases like diabetes. PMID:28837703

Latrunculin A Treatment Prevents Abnormal Chromosome Segregation for Successful Development of Cloned Embryos

PubMed Central

Terashita, Yukari; Yamagata, Kazuo; Tokoro, Mikiko; Itoi, Fumiaki; Wakayama, Sayaka; Li, Chong; Sato, Eimei; Tanemura, Kentaro; Wakayama, Teruhiko

2013-01-01

Somatic cell nuclear transfer to an enucleated oocyte is used for reprogramming somatic cells with the aim of achieving totipotency, but most cloned embryos die in the uterus after transfer. While modifying epigenetic states of cloned embryos can improve their development, the production rate of cloned embryos can also be enhanced by changing other factors. It has already been shown that abnormal chromosome segregation (ACS) is a major cause of the developmental failure of cloned embryos and that Latrunculin A (LatA), an actin polymerization inhibitor, improves F-actin formation and birth rate of cloned embryos. Since F-actin is important for chromosome congression in embryos, here we examined the relation between ACS and F-actin in cloned embryos. Using LatA treatment, the occurrence of ACS decreased significantly whereas cloned embryo-specific epigenetic abnormalities such as dimethylation of histone H3 at lysine 9 (H3K9me2) could not be corrected. In contrast, when H3K9me2 was normalized using the G9a histone methyltransferase inhibitor BIX-01294, the Magea2 gene—essential for normal development but never before expressed in cloned embryos—was expressed. However, this did not increase the cloning success rate. Thus, non-epigenetic factors also play an important role in determining the efficiency of mouse cloning. PMID:24205216

Glutathione and abscisic acid supplementation influences somatic embryo maturation and hormone endogenous levels during somatic embryogenesis in Podocarpus lambertii Klotzsch ex Endl.

PubMed

Fraga, Hugo Pacheco de Freitas; Vieira, Leila do Nascimento; Puttkammer, Catarina Corrêa; Dos Santos, Henrique Pessoa; Garighan, Julio de Andrade; Guerra, Miguel Pedro

2016-12-01

Here we propose a protocol for embryogenic cultures induction, proliferation and maturation for the Brazilian conifer Podocarpus lambertii, and investigated the effect of abscisic acid (ABA) and glutathione (GSH) supplementation on the maturation phase. ABA, zeatin (Z) and salicylic acid (SA) endogenous levels were quantified. Number of somatic embryos obtained in ABA-supplemented treatment was significant higher than in ABA-free treatment, showing the relevance of ABA supplementation during somatic embryos maturation. Histological analysis showed the stereotyped sequence of developmental stages in conifer somatic embryos, reaching the late torpedo-staged embryo. GSH supplementation in maturation culture medium improved the somatic embryos number and morphological features. GSH 0mM and GSH 0.1mM treatments correlated with a decreased ABA endogenous level during maturation, while GSH 0.5mM treatment showed constant levels. All treatments resulted in decreased Z endogenous levels, supporting the concept that cytokinins are important during the initial cell division but not for the later stages of embryo development. The lowest SA levels found in GSH 0.5mM treatment were coincident with early embryonic development, and this treatment resulted in the highest development of somatic embryos. Thus, a correlation between lower SA levels and improved somatic embryo formation can be hypothesized. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Laser fusion of mouse embryonic cells and intra-embryonic fusion of blastomeres without affecting the embryo integrity.

PubMed

Krivokharchenko, Alexander; Karmenyan, Artashes; Sarkisov, Oleg; Bader, Michael; Chiou, Arthur; Shakhbazyan, Avetik

2012-01-01

Manipulation with early mammalian embryos is the one of the most important approach to study preimplantation development. Artificial cell fusion is a research tool for various biotechnological experiments. However, the existing methods have various disadvantages, first of them impossibility to fuse selected cells within multicellular structures like mammalian preimplantation embryos. In our experiments we have successfully used high repetition rate picosecond near infrared laser beam for fusion of pairs of oocytes and oocytes with blastomeres. Fused cells looked morphologically normal and keep their ability for further divisions in vitro. We also fused two or three blastomeres inside four-cell mouse embryos. The presence of one, two or three nuclei in different blastomeres of the same early preimplantation mouse embryo was confirmed under UV-light after staining of DNA with the vital dye Hoechst-33342. The most of established embryos demonstrated high viability and developed in vitro to the blastocyst stage. We demonstrated for the first time the use of laser beam for the fusion of various embryonic cells of different size and of two or three blastomeres inside of four-cell mouse embryos without affecting the embryo's integrity and viability. These embryos with blastomeres of various ploidy maybe unique model for numerous purposes. Thus, we propose laser optical manipulation as a new tool for investigation of fundamental mechanisms of mammalian development.

Whole embryo culture: a "New" technique that enabled decades of mechanistic discoveries.

PubMed

Ellis-Hutchings, Robert G; Carney, Edward W

2010-08-01

Denis New's development of the rodent whole embryo culture (WEC) method in the early 1960s was a groundbreaking achievement that gave embryologists and teratologists an unprecedented degree of access to the developing postimplantation rodent embryo. In the five decades since its development, WEC has enabled detailed investigations into the regulation of normal embryo development as well as a plethora of research on mechanisms of teratogenesis as induced by a wide range of agents. In addition, WEC is one of the few techniques that has been validated for use in teratogenicity screening of drugs and chemicals. In this review, we retrace the steps leading to New's development of WEC, and highlight many examples in which WEC played a crucial role leading to important discoveries in teratological research. The impact of WEC on the field of teratology has been enormous, and it is anticipated that WEC will remain a preferred tool for teratologists and embryologists seeking to interrogate embryo development for many years to come. Copyright 2010 Wiley-Liss, Inc.

Development of Embryonic Market Squid, Doryteuthis opalescens, under Chronic Exposure to Low Environmental pH and [O2].

PubMed

Navarro, Michael O; Kwan, Garfield T; Batalov, Olga; Choi, Chelsea Y; Pierce, N Tessa; Levin, Lisa A

2016-01-01

The market squid, Doryteuthis opalescens, is an important forage species for the inshore ecosystems of the California Current System. Due to increased upwelling and expansion of the oxygen minimum zone in the California Current Ecosystem, the inshore environment is expected to experience lower pH and [O2] conditions in the future, potentially impacting the development of seafloor-attached encapsulated embryos. To understand the consequences of this co-occurring environmental pH and [O2] stress for D. opalescens encapsulated embryos, we performed two laboratory experiments. In Experiment 1, embryo capsules were chronically exposed to a treatment of higher (normal) pH (7.93) and [O2] (242 μM) or a treatment of low pH (7.57) and [O2] (80 μM), characteristic of upwelling events and/or La Niña conditions. The low pH and low [O2] treatment extended embryo development duration by 5-7 days; embryos remained at less developed stages more often and had 54.7% smaller statolith area at a given embryo size. Importantly, the embryos that did develop to mature embryonic stages grew to sizes that were similar (non-distinct) to those exposed to the high pH and high [O2] treatment. In Experiment 2, we exposed encapsulated embryos to a single stressor, low pH (7.56) or low [O2] (85 μM), to understand the importance of environmental pH and [O2] rising and falling together for squid embryogenesis. Embryos in the low pH only treatment had smaller yolk reserves and bigger statoliths compared to those in low [O2] only treatment. These results suggest that D. opalescens developmental duration and statolith size are impacted by exposure to environmental [O2] and pH (pCO2) and provide insight into embryo resilience to these effects.

Development of Embryonic Market Squid, Doryteuthis opalescens, under Chronic Exposure to Low Environmental pH and [O2

PubMed Central

Navarro, Michael O.; Kwan, Garfield T.; Batalov, Olga; Choi, Chelsea Y.; Pierce, N. Tessa; Levin, Lisa A.

2016-01-01

The market squid, Doryteuthis opalescens, is an important forage species for the inshore ecosystems of the California Current System. Due to increased upwelling and expansion of the oxygen minimum zone in the California Current Ecosystem, the inshore environment is expected to experience lower pH and [O2] conditions in the future, potentially impacting the development of seafloor-attached encapsulated embryos. To understand the consequences of this co-occurring environmental pH and [O2] stress for D. opalescens encapsulated embryos, we performed two laboratory experiments. In Experiment 1, embryo capsules were chronically exposed to a treatment of higher (normal) pH (7.93) and [O2] (242 μM) or a treatment of low pH (7.57) and [O2] (80 μM), characteristic of upwelling events and/or La Niña conditions. The low pH and low [O2] treatment extended embryo development duration by 5–7 days; embryos remained at less developed stages more often and had 54.7% smaller statolith area at a given embryo size. Importantly, the embryos that did develop to mature embryonic stages grew to sizes that were similar (non-distinct) to those exposed to the high pH and high [O2] treatment. In Experiment 2, we exposed encapsulated embryos to a single stressor, low pH (7.56) or low [O2] (85 μM), to understand the importance of environmental pH and [O2] rising and falling together for squid embryogenesis. Embryos in the low pH only treatment had smaller yolk reserves and bigger statoliths compared to those in low [O2] only treatment. These results suggest that D. opalescens developmental duration and statolith size are impacted by exposure to environmental [O2] and pH (pCO2) and provide insight into embryo resilience to these effects. PMID:27936085

Role of glucose in mouse preimplantation embryo development.

PubMed

Martin, K L; Leese, H J

1995-04-01

Mouse preimplantation embryos consume pyruvate preferentially during the early developmental stages, before glucose becomes the predominant energy substrate in the blastocyst. To investigate the importance of the switch to glucose utilization at the later developmental stages, mouse embryos from F1 hybrid mice (CBA/Ca x C57BL/6) were cultured from the one- and two-cell stages (22 and 46 h post hCG, respectively) for 5 days in a modified medium, M16, containing 0.33 mM pyruvate and 5 or 23 mM D + L-lactate, in the presence and absence of 1 mM glucose (M16 + G and M16 - G, respectively). Nutrient uptakes were also determined over this time. Some embryos cultured in M16 - G were transferred to M16 + G at 94 or 118 h post hCG. Embryos cultured from the two-cell stage in M16 + G exhibited the characteristic fall in pyruvate consumption between the morula and the blastocyst stage; those cultured from the two-cell stage in M16 - G compensated for the lack of glucose by consuming increasing amounts of pyruvate, from 2.78 pmol/embryo/h at 58 h post hCG to 5.21 pmol/embryo/h at 154 h post hCG. However, the percentage of embryos developing to the blastocyst stage, the hatching rate, and blastocyst cell numbers (50.6 +/- 2.5 [28] vs. 105 +/- 3.8 [37]) were all lower in this group. When exposed to glucose at 94 or 118 h post hCG, embryos cultured from the two-cell stage in M16 - G readily consumed glucose in preference to pyruvate, although the characteristic fall in pyruvate consumption was not observed. One-cell embryos cultured continuously in M16 - G were only able to develop to the morula stage, after which time they degenerated. In these embryos pyruvate was readily consumed between 22 and 94 h post hCG, before falling from 2.77 pmol/embryo/h at 83 h post hCG to 0.045 pmol/embryo/h at 130 h post hCG. Transfer of these embryos to M16 + G at 94 and 118 h post hCG did not support development to the hatching blastocyst stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronology of early embryonic development and embryo uterine migration in alpacas.

PubMed

Picha, Y; Tibary, A; Memon, M; Kasimanickam, R; Sumar, J

2013-03-01

The objectives were to: (1) describe the chronology of early embryonic development from ovulation to entry into the uterus; and (2) to determine the timing of embryo migration to the left uterine horn when ovulation occurred from the right ovary. The experiment was conducted in Peru. Females (n = 132) were randomly assigned to 15 experimental groups. All females were mated to an intact male, given 50 μg GnRH im (Cystorelin) and ovulation time determined by transrectal ultrasonography, conducted every 6 hours, starting 24 hours postmating. Animals were slaughtered at a specific intervals postovulation and reproductive tracts were recovered and subjected to oviductal and uterine flushing for females slaughtered between 1 and 6 days postovulation (dpo; Day 0 = ovulation) and uterine flushing for females slaughtered from 7 to 15 dpo for recovery of oocytes/embryos. Season of mating did not influence the interval from mating to ovulation (winter: 29 ± 6 hours vs. summer: 30 ± 6 hours; P = 0.49). Ovulation rates for females mated during winter and summer were 92% versus 100%, respectively (P = 0.05). Fertilization rates for winter and summer mated females were 72% and 82% (P = 0.29). Unfertilized ova were not retained in the uterine tube. All embryos collected were in the uterine tube ipsilateral to the side of ovulation between 1 and 5 dpo. Embryos reached the uterus on 6 dpo. Embryos began to elongate on 9 dpo; at this time, 83% of embryos derived from right-ovary ovulations were collected from the left uterine horn. Embryos occupied the entire uterine cavity by 10 dpo. In conclusion, we characterized early embryo development and location of embryo during its early developmental stages in alpaca. This was apparently the first report regarding chronology of embryo development and migration to the left horn in alpaca which merits further investigation regarding its role in maternal recognition of pregnancy. Copyright © 2013 Elsevier Inc. All rights reserved.

An improved embryo-rescue protocol for hybrid progeny from seedless Vitis vinifera grapes × wild Chinese Vitis species.

PubMed

Li, Gui Rong; Ji, Wei; Wang, Gang; Zhang, Jian Xia; Wang, Yue Jin

A highly efficient technique of embryo rescue is critical when using stenospermocarpic Vitis vinifera cultivars (female parents) to breed novel, disease-resistant, seedless grape cultivars by hybridizing with wild Chinese Vitis species (male parents) having many disease-resistance alleles. The effects of various factors on the improvement of embryo formation, germination, and plantlet development for seven hybrid combinations were studied. The results indicated that Beichun and Shuangyou were the best male parents. The best sampling time for ovule inoculation differed among the female parents. When hybrid ovules were cultured on a double-phase medium with five different solid medium types, percent embryo formation was highest (11.3-28.3%) on a modified MM3 medium. Percentages of embryo germination (15.4-55.4%) and plantlet development (11.15-44.6%) were all highest when embryos were cultured on Woody Plant Medium + 5.7 μM indole-3-acetic acid + 4.4 μM 6-benzylaminopurine + 1.4 μM gibberellic acid + 2% sucrose + 0.05% casein hydrolysate + 0.3% activated charcoal + 0.7% agar. In the absence of other amino acids, the addition of proline significantly increased embryo formation (36.1%), embryo germination (64.6%), and plantlet development (90.5%). A highly efficient protocol has been developed for hybrid embryo rescue from seedless V. vinifera grapes × wild Chinese Vitis species that results in a significant improvement in breeding efficiency for new disease-resistant seedless grapes.

Cutter Connectivity Bandwidth Study

DTIC Science & Technology

2002-10-01

U.S. Coast Guard Research and Development Center 1082 Shennecossett Road, Groton, CT 06340-6096 Report No. CG-D-03-02 CUTTER CONNECTIVITY BANDWIDTH...or regulation. Marc B. Mandler, Ph.D. Technical Director United States Coast Guard Research & Development Center 1082 Shennecossett Road Groton, CT...Organization Report No. R&DC 617 9. Performing Organization Name and Address U.S. Coast Guard Research and Development Center 1082 Shennecossett Road

Barcode tagging of human oocytes and embryos to prevent mix-ups in assisted reproduction technologies.

PubMed

Novo, Sergi; Nogués, Carme; Penon, Oriol; Barrios, Leonardo; Santaló, Josep; Gómez-Martínez, Rodrigo; Esteve, Jaume; Errachid, Abdelhamid; Plaza, José Antonio; Pérez-García, Lluïsa; Ibáñez, Elena

2014-01-01

Is the attachment of biofunctionalized polysilicon barcodes to the outer surface of the zona pellucida an effective approach for the direct tagging and identification of human oocytes and embryos during assisted reproduction technologies (ARTs)? The direct tagging system based on lectin-biofunctionalized polysilicon barcodes of micrometric dimensions is simple, safe and highly efficient, allowing the identification of human oocytes and embryos during the various procedures typically conducted during an assisted reproduction cycle. Measures to prevent mismatching errors (mix-ups) of the reproductive samples are currently in place in fertility clinics, but none of them are totally effective and several mix-up cases have been reported worldwide. Using a mouse model, our group has previously developed an effective direct embryo tagging system which does not interfere with the in vitro and in vivo development of the tagged embryos. This system has now been tested in human oocytes and embryos. Fresh immature and mature fertilization-failed oocytes (n = 21) and cryopreserved day 1 embryos produced by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) (n = 205) were donated by patients (n = 76) undergoing ARTs. In vitro development rates, embryo quality and post-vitrification survival were compared between tagged (n = 106) and non-tagged (control) embryos (n = 99). Barcode retention and identification rates were also calculated, both for embryos and for oocytes subjected to a simulated ICSI and parthenogenetic activation. Experiments were conducted from January 2012 to January 2013. Barcodes were fabricated in polysilicon and biofunctionalizated with wheat germ agglutinin lectin. Embryos were tagged with 10 barcodes and cultured in vitro until the blastocyst stage, when they were either differentially stained with propidium iodide and Hoechst or vitrified using the Cryotop method. Embryo quality was also analyzed by embryo grading and time-lapse monitoring. Injected oocytes were parthenogenetically activated using ionomycin and 6-dimethylaminopurine. Blastocyst development rates of tagged (27/58) and non-tagged embryos (24/51) were equivalent, and no significant differences in the timing of key morphokinetic parameters and the number of inner cell mass cells were detected between the two groups (tagged: 24.7 ± 2.5; non-tagged: 22.3 ± 1.9), indicating that preimplantation embryo potential and quality are not affected by the barcodes. Similarly, re-expansion rates of vitrified-warmed tagged (19/21) and non-tagged (16/19) blastocysts were similar. Global identification rates of 96.9 and 89.5% were obtained in fresh (mean barcode retention: 9.22 ± 0.13) and vitrified-warmed (mean barcode retention: 7.79 ± 0.35) tagged embryos, respectively, when simulating an automatic barcode reading process, though these rates were increased to 100% just by rotating the embryos during barcode reading. Only one of the oocytes lost one barcode during intracytoplasmic injection (100% identification rate) and all oocytes retained all the barcodes after parthenogenetic activation. Although the direct embryo tagging system developed is effective, it only allows the identification and traceability of oocytes destined for ICSI and embryos. Thus, the traceability of all reproductive samples (oocytes destined for IVF and sperm) is not yet ensured. The direct embryo tagging system developed here provides fertility clinics with a novel tool to reduce the risk of mix-ups in human ARTs. The system can also be useful in research studies that require the individual identification of oocytes or embryos and their individual tracking. This study was supported by the Sociedad Española de Fertilidad, the Spanish Ministry of Education and Science (TEC2011-29140-C03) and the Generalitat de Catalunya (2009SGR-00282 and 2009SGR-00158). The authors do not have any competing interests.

Development of a new clinically applicable device for embryo evaluation which measures embryo oxygen consumption.

PubMed

Kurosawa, Hiroki; Utsunomiya, Hiroki; Shiga, Naomi; Takahashi, Aiko; Ihara, Motomasa; Ishibashi, Masumi; Nishimoto, Mitsuo; Watanabe, Zen; Abe, Hiroyuki; Kumagai, Jin; Terada, Yukihiro; Igarashi, Hideki; Takahashi, Toshifumi; Fukui, Atsushi; Suganuma, Ryota; Tachibana, Masahito; Yaegashi, Nobuo

2016-10-01

Does a new system-the chip-sensing embryo respiration monitoring system (CERMs)-enable evaluation of embryo viability for potential application in a clinical IVF setting? The system enabled the oxygen consumption rate of spheroids, bovine embryos and frozen-thawed human embryos to be measured, and this rate corresponded to the developmental potential of embryos. To date, no reliable and clinically suitable objective evaluation methods for embryos are available, which circumvent the differences in inter-observer subjective view. Existing systems such as the scanning electrochemical microscopy (SECM) technique, which enables the measurement of oxygen consumption rate in embryos, need improvement in usability before they can be applied to a clinical setting. This is a prospective original research study. The feasibility of measuring the oxygen consumption rate was assessed using CERMs for 9 spheroids, 9 bovine embryos and 30 redundant frozen-thawed human embryos. The endpoints for the study were whether CERMs could detect a dissolved oxygen gradient with high sensitivity, had comparable accuracy to the SECM measuring system with improved usability, and could predict the development of an embryo to a blastocyst by measuring the oxygen consumption rate. The relationship between the oxygen consumption rate and standard morphological evaluation was also examined. We developed a new CERMs, which enables the oxygen consumption rate to be measured automatically using an electrochemical method. The device was initially used for measuring a dissolved oxygen concentration gradient in order to calculate oxygen consumption rate using nine spheroids. Next, we evaluated data correlation between the CERMs and the SECM measuring systems using nine bovine embryos. Finally, the oxygen consumption rates of 30 human embryos, which were frozen-thawed on 2nd day after fertilization, were measured by CERMs at 6, 24, 48, 72 and 96 h after thawing with standard morphological evaluation. Furthermore, the developed blastocysts were scored using the blastocyst quality score (BQS), and the correlation with oxygen consumption rate was also assessed. The device enabled the oxygen consumption rate of an embryo to be measured automatically within a minute. The oxygen concentration gradient profile showed excellent linearity in a distance-dependent change. A close correlation in the oxygen consumption rates of bovine embryos was observed between the SECM measuring system and CERMs, with a determination coefficient of 0.8203 (P = 0.0008). Oxygen consumption rates of human embryos that have reached the blastocyst stage were significantly higher than those of arrested embryos at 48, 72 and 96 h after thawing (P = 0.039, 0.004 and 0.049, respectively). Thus, in vitro development of frozen-thawed human embryos to the blastocyst stage would be predicted at 48 h after thawing (day 4) by measuring the oxygen consumption using CERMs. Although a positive linear relationship between BQS and the oxygen consumption rate was observed [the determination coefficient was R(2) = 0.6537 (P = 0.008)], two blastocysts exhibited low oxygen consumption rates considering their relatively high BQS. This suggests that morphology and metabolism in human embryos might not correlate consistently. Transfer of the embryo and pregnancy evaluation was not performed. Thus, a correlation between oxygen consumption and the in vivo viability of embryos remains unknown. Clinical trials, including embryo transfer, would be desirable to determine a threshold value to elect clinically relevant, quality embryos for transfer. We utilized frozen-thawed human embryos in this study. The effect of these manipulations on the respiratory activity of the embryo is also unknown. Selection of quality embryos, especially in a single embryo transfer cycle, by CERMs may have an impact on obtaining better clinical outcomes, albeit with clinical trials being required. Furthermore, the early determination of quality embryos by CERMs may enable the omission of long-term in vitro embryo culture to the blastocyst stage. CERMs is scalable technology that can be integrated into incubators and/or other embryo evaluation systems, such as the time-lapse systems, due to its chip-based architecture. Thus, CERMS would enable automatic measurement of oxygen consumption, under 5% CO2, in the near future, in order to reduce oxidative stress from exposure to atmospheric air. This study was supported by grants from the Health and Labor Sciences Research Grant (H24-Hisaichiiki-Shitei-016). The authors have no conflicts of interest. Not applicable. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Strain preservation of experimental animals: vitrification of two-cell stage embryos for multiple mouse strains.

PubMed

Eto, Tomoo; Takahashi, Riichi; Kamisako, Tsutomu

2015-04-01

Strain preservation of experimental animals is crucial for experimental reproducibility. Maintaining complete animal strains, however, is costly and there is a risk for genetic mutations as well as complete loss due to disasters or illness. Therefore, the development of effective vitrification techniques for cryopreservation of multiple experimental animal strains is important. We examined whether a vitrification method using cryoprotectant solutions, P10 and PEPeS, is suitable for preservation of multiple inbred and outbred mouse strains. First, we investigated whether our vitrification method using cryoprotectant solutions was suitable for two-cell stage mouse embryos. In vitro development of embryos exposed to the cryoprotectant solutions was similar to that of fresh controls. Further, the survival rate of the vitrified embryos was extremely high (98.1%). Next, we collected and vitrified two-cell stage embryos of 14 mouse strains. The average number of embryos obtained from one female was 7.3-33.3. The survival rate of vitrified embryos ranged from 92.8% to 99.1%, with no significant differences among mouse strains. In vivo development did not differ significantly between fresh controls and vitrified embryos of each strain. For strain preservation using cryopreserved embryos, two offspring for inbred lines and one offspring for outbred lines must be produced from two-cell stage embryos collected from one female. The expected number of surviving fetuses obtained from embryos collected from one female of either the inbred or outbred strains ranged from 2.9 to 19.5. The findings of the present study indicated that this vitrification method is suitable for strain preservation of multiple mouse strains. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Attitudes of Infertile Couples, Fertility Clinic Staff and Researchers toward Personhood of The Human Embryo in Iran

PubMed Central

Kayssan, Marjaneh; Dolatian, Mahrokh; Omani Samani, Reza; Maroufizadeh, Saman

2017-01-01

Objective After the introduction of assisted reproductive techniques, human embryos were officially introduced into laboratories and now thousands of them are cryopreserved in such settings. Embryonic stem cells and the future application of such cells in the treatment of disease opened the door to further research on human embryos. These developments raise many ethical issues, some of which have religious aspects. The main question is: what is the embryo? Should we consider it a human being? Thus, the purpose of this study was to investigate attitudes towards the personhood of the embryo. Materials and Methods In this cross sectional study, 203 infertile patients (n=406), 54 clinic staff and 49 embryo researchers, selected using convenience sampling at the Royan Institute, completed a questionnaire on personhood of human embryo. The questionnaire had been developed following qualitative research and had satisfied face and content validity tests. Results At the pre-implantation stage the majority of participants in all three groups considered the human embryo as "not a human being". Also, at the post-implantation stage of development, the majority of infertile couples and clinic staff considered the embryo as "not a human being" but, half the researchers (51%) considered the embryo in this stage as a "potential human". Half of the infertile couples considered the human fetus before ensoulment time (19th week of pregnancy according to the Shiite Islamic scholars) as "not-human being", while more than half of researchers (55.1%) considered it as a "potential human". Conclusion Ensoulment time is a major and important border for personhood. Most infertile couples and clinic staff consider the human embryo as "not a human being" but majority of all study participants considered the human fetus to be a complete human after ensoulment time. PMID:28670524

Effects of in vitro fertilization and embryo culture on TRP53 and Bax expression in B6 mouse embryos.

PubMed

Chandrakanthan, Vashe; Li, Aiqing; Chami, Omar; O'Neill, Christopher

2006-11-21

In the mouse, embryo culture results in a characteristic phenotype of retarded embryo preimplantation development and reduced numbers of cells within embryos. The expression of TRP53 is central to the regulation of the cell's capacity to proliferate and survive. In this study we found that Trp53 mRNA is expressed throughout the preimplantation stage of development. Levels of TRP53 protein expression were low during the cleavage stages and increased at the morula and blastocyst stages in B6 embryos collected from the reproductive tract. Embryos collected at the zygote stage and cultured for 96 h also showed low levels of TRP53 expression at precompaction stages. There were higher levels of TRP53 in cultured morula and the level in cultured blastocysts was clearly increased above blastocysts collected directly from the uterus. Immunolocalization of TRP53 showed that its increased expression in cultured blastocysts corresponded with a marked accumulation of TRP53 within the nuclei of embryonic cells. This pattern of expression was enhanced in embryos produced by in vitro fertilization and subjected to culture. The TRP53 was transcriptionally active since culture also induced increased expression of Bax, yet this did not occur in embryos lacking Trp53 (Trp53-/-). The rate of development of Trp53-/- zygotes to the blastocyst stage was not different to wildtype controls when embryos were cultured in groups of ten but was significantly faster when cultured individually. The results show that zygote culture resulted in the accumulation of transcription activity of TRP53 in the resulting blastocysts. This accounts for the adverse effects of culture of embryos individually, but does not appear to be the sole cause of the retarded preimplantation stage growth phenotype associated with culture in vitro.

A minimally invasive methodology based on morphometric parameters for day 2 embryo quality assessment.

PubMed

Molina, Inmaculada; Lázaro-Ibáñez, Elisa; Pertusa, Jose; Debón, Ana; Martínez-Sanchís, Juan Vicente; Pellicer, Antonio

2014-10-01

The risk of multiple pregnancy to maternal-fetal health can be minimized by reducing the number of embryos transferred. New tools for selecting embryos with the highest implantation potential should be developed. The aim of this study was to evaluate the ability of morphological and morphometric variables to predict implantation by analysing images of embryos. This was a retrospective study of 135 embryo photographs from 112 IVF-ICSI cycles carried out between January and March 2011. The embryos were photographed immediately before transfer using Cronus 3 software. Their images were analysed using the public program ImageJ. Significant effects (P < 0.05), and higher discriminant power to predict implantation were observed for the morphometric embryo variables compared with morphological ones. The features for successfully implanted embryos were as follows: four cells on day 2 of development; all blastomeres with circular shape (roundness factor greater than 0.9), an average zona pellucida thickness of 13 µm and an average of 17695.1 µm² for the embryo area. Embryo size, which is described by its area and the average roundness factor for each cell, provides two objective variables to consider when predicting implantation. This approach should be further investigated for its potential ability to improve embryo scoring. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Complete method to obtain, culture, and transfer mouse blastocysts nonsurgically to study implantation and development.

PubMed

Moreno-Moya, Juan Manuel; Ramírez, Leslie; Vilella, Felipe; Martínez, Sebastián; Quiñonero, Alicia; Noguera, Inmaculada; Pellicer, Antonio; Simón, Carlos

2014-03-01

To illustrate an efficient, complete, step-by-step protocol for studying implantation in mice. Video presentation of an animal model for research in reproductive biology. Mouse (Mus musculus). A nonsurgical embryo transfer system very similar to that used for human embryo transfer. The protocols with recipient and donor mice are performed in parallel in the same week. For the donor mice: the first step is ovarian stimulation, followed by ovulation induction and mating; finally, the mice are sacrificed, and the embryos are collected and cultured. For recipient mice: first estrous synchrony is induced, followed by mating with a vasectomized male, visualization of the vaginal plug, and nonsurgical transfer of the embryos. Finally (optionally), the implantation sites can be visualized on day 7.5 of development. (All animal experiments were performed with the approval of the institutional review board.) Implantation is an essential step in human reproduction although, because of technical and ethics considerations, still relatively little is known about human implantation and early development. Conversely, mouse models are well established and can be used for preliminary experiments. However, there are various bottlenecks in the procedure for obtaining and transferring murine embryos, which makes experimentation with this model more difficult. These difficulties include pseudopregnancy, ovarian hyperstimulation, and embryo collection, culture, and transfer. We have proposed a complete, efficient method for obtaining, culturing, and transferring mouse blastocysts that can be easily applied in research. Potential applications include testing new media components that do not affect preimplantation but do affect implantation and early development. The embryo transfer method proposed here has been demonstrated to achieve embryo implantation easier and faster than, and in approximately similar rates as other traditional surgery methods. This workflow is the first set of complete step-by-step instructions available that incorporate advances such as nonsurgical mouse embryo transfer. This will facilitate research into different reproduction events such as embryo development, embryo implantation, or contraception. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Time to take human embryo culture seriously.

PubMed

Sunde, Arne; Brison, Daniel; Dumoulin, John; Harper, Joyce; Lundin, Kersti; Magli, M Cristina; Van den Abbeel, Etienne; Veiga, Anna

2016-10-01

Is it important that end-users know the composition of human embryo culture media? We argue that there is as strong case for full transparency concerning the composition of embryo culture media intended for human use. Published data suggest that the composition of embryo culture media may influence the phenotype of the offspring. A review of the literature was carried out. Data concerning the potential effects on embryo development of culture media were assessed and recommendations for users made. The safety of ART procedures, especially with respect to the health of the offspring, is of major importance. There are reports from the literature indicating a possible effect of culture conditions, including culture media, on embryo and fetal development. Since the introduction of commercially available culture media, there has been a rapid development of different formulations, often not fully documented, disclosed or justified. There is now evidence that the environment the early embryo is exposed to can cause reprogramming of embryonic growth leading to alterations in fetal growth trajectory, birthweight, childhood growth and long-term disease including Type II diabetes and cardiovascular problems. The mechanism for this is likely to be epigenetic changes during the preimplantation period of development. In the present paper the ESHRE working group on culture media summarizes the present knowledge of potential effects on embryo development related to culture media, and makes recommendations. There is still a need for large prospective randomized trials to further elucidate the link between the composition of embryo culture media used and the phenotype of the offspring. We do not presently know if the phenotypic changes induced by in vitro embryo culture represent a problem for long-term health of the offspring. Published data indicate that there is a strong case for demanding full transparency concerning the compositions of and the scientific rationale behind the composition of embryo culture media. This work was funded by The European Society for Human Reproduction and Embryology. No competing interests to declare. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Exposure to high ambient temperatures alters embryology in rabbits

NASA Astrophysics Data System (ADS)

García, M. L.; Argente, M. J.

2017-09-01

High ambient temperatures are a determining factor in the deterioration of embryo quality and survival in mammals. The aim of this study was to evaluate the effect of heat stress on embryo development, embryonic size and size of the embryonic coats in rabbits. A total of 310 embryos from 33 females in thermal comfort zone and 264 embryos of 28 females in heat stress conditions were used in the experiment. The traits studied were ovulation rate, percentage of total embryos, percentage of normal embryos, embryo area, zona pellucida thickness and mucin coat thickness. Traits were measured at 24 and 48 h post-coitum (hpc); mucin coat thickness was only measured at 48 hpc. The embryos were classified as zygotes or two-cell embryos at 24 hpc, and 16-cells or early morulae at 48 hpc. The ovulation rate was one oocyte lower in heat stress conditions than in thermal comfort. Percentage of normal embryos was lower in heat stress conditions at 24 hpc (17.2%) and 48 hpc (13.2%). No differences in percentage of zygotes or two-cell embryos were found at 24 hpc. The embryo development and area was affected by heat stress at 48 hpc (10% higher percentage of 16-cells and 883 μm2 smaller, respectively). Zona pellucida was thicker under thermal stress at 24 hpc (1.2 μm) and 48 hpc (1.5 μm). No differences in mucin coat thickness were found. In conclusion, heat stress appears to alter embryology in rabbits.

Demi-embryo production from hatching of zona-drilled bovine and rabbit blastocysts.

PubMed

Skrzyszowska, M; Smorag, Z; Katska, L

1997-09-01

It is known that the pregnancy rate resulting after transfer of bisected embryos is lower than after transfer of whole embryos. The main reason is the reduced cell number in the demi-embryo which is less than 1 2 of that in the intact embryo, since a number of blastomeres is damaged as a result of the procedure used in conventional embryo splitting. The aim of our experiment was to develop a non-invasive procedure which would limit cell losses during microsurgery. The experiment was carried out on bovine IVM-IVF embryos at middle, late and expanded blastocyst stage and rabbit embryos at late blastocyst stage cultured in vitro from in vivo produced zygotes. The zona pellucida of these embryos was drilled on the line between the inner cell mass and the trophoblast using a glass microneedle (

PGF₂α levels in Day 8 blood plasma are increased by the presence of one or more embryos in the uterus.

PubMed

Gomez, E; Martin, D; Carrocera, S; Muñoz, M

2015-08-01

In cattle, the detection of very early endometrial responses is considered to be hampered by the presence of only a single embryo. Therefore, we have previously developed a model of multiple embryo transfer to circumvent this hindrance. In this work, we analysed embryo-maternal interactions in the bovine uterus on day 8 of development while comparing the presence of multiple v. single embryos using embryo transfer and artificial insemination, respectively. Concentration of proteins (β-actin, NFkB, clusterin and immunoproteosome 20S β5i subunit-i20S), by western blot, and hexoses (glucose and fructose) were measured in paired samples of uterine fluid (UF) from the same animal with and without embryos in the uterus and were compared with UF obtained after artificial insemination. Prostaglandin (PG) F2 α and PGE2 concentrations were also analysed in blood plasma. The four proteins analysed and hexoses were unaffected by the presence of one or more embryos in the uterus. However, blood PGF2 α showed similar, significant increases with one or more embryos over cyclic animals; such changes were not observed in blood PGE2. Although multiple embryo transfer may appear to be non-physiological, we showed that the uterus, at the very early embryonic stages, does exhibit physiological reactions. Multiple embryo transfer can, therefore, be used for studies of very early embryo-maternal interactions in vivo in monotocous species.

Effects of duration of electric pulse on in vitro development of cloned cat embryos with human artificial chromosome vector.

PubMed

Do, Ltk; Wittayarat, M; Terazono, T; Sato, Y; Taniguchi, M; Tanihara, F; Takemoto, T; Kazuki, Y; Kazuki, K; Oshimura, M; Otoi, T

2016-12-01

The current applications for cat cloning include production of models for the study of human and animal diseases. This study was conducted to investigate the optimal fusion protocol on in vitro development of transgenic cloned cat embryos by comparing duration of electric pulse. Cat fibroblast cells containing a human artificial chromosome (HAC) vector were used as genetically modified nuclear donor cells. Couplets were fused and activated simultaneously with a single DC pulse of 3.0 kV/cm for either 30 or 60 μs. Low rates of fusion and embryo development to the blastocyst stage were observed in the reconstructed HAC-transchromosomic embryos, when the duration of fusion was prolonged to 60 μs. In contrast, the prolongation of electric pulse duration improved the embryo development and quality in the reconstructed control embryos without HAC vector. Our results suggested that the optimal parameters of electric pulses for fusion in cat somatic cell nuclear transfer vary among the types used for donor cells. © 2016 Blackwell Verlag GmbH.

Patterning in time and space: HoxB cluster gene expression in the developing chick embryo.

PubMed

Gouveia, Analuce; Marcelino, Hugo M; Gonçalves, Lisa; Palmeirim, Isabel; Andrade, Raquel P

2015-01-01

The developing embryo is a paradigmatic model to study molecular mechanisms of time control in Biology. Hox genes are key players in the specification of tissue identity during embryo development and their expression is under strict temporal regulation. However, the molecular mechanisms underlying timely Hox activation in the early embryo remain unknown. This is hindered by the lack of a rigorous temporal framework of sequential Hox expression within a single cluster. Herein, a thorough characterization of HoxB cluster gene expression was performed over time and space in the early chick embryo. Clear temporal collinearity of HoxB cluster gene expression activation was observed. Spatial collinearity of HoxB expression was evidenced in different stages of development and in multiple tissues. Using embryo explant cultures we showed that HoxB2 is cyclically expressed in the rostral presomitic mesoderm with the same periodicity as somite formation, suggesting a link between timely tissue specification and somite formation. We foresee that the molecular framework herein provided will facilitate experimental approaches aimed at identifying the regulatory mechanisms underlying Hox expression in Time and Space.

Patterning in time and space: HoxB cluster gene expression in the developing chick embryo

PubMed Central

Gouveia, Analuce; Marcelino, Hugo M; Gonçalves, Lisa; Palmeirim, Isabel; Andrade, Raquel P

2015-01-01

The developing embryo is a paradigmatic model to study molecular mechanisms of time control in Biology. Hox genes are key players in the specification of tissue identity during embryo development and their expression is under strict temporal regulation. However, the molecular mechanisms underlying timely Hox activation in the early embryo remain unknown. This is hindered by the lack of a rigorous temporal framework of sequential Hox expression within a single cluster. Herein, a thorough characterization of HoxB cluster gene expression was performed over time and space in the early chick embryo. Clear temporal collinearity of HoxB cluster gene expression activation was observed. Spatial collinearity of HoxB expression was evidenced in different stages of development and in multiple tissues. Using embryo explant cultures we showed that HoxB2 is cyclically expressed in the rostral presomitic mesoderm with the same periodicity as somite formation, suggesting a link between timely tissue specification and somite formation. We foresee that the molecular framework herein provided will facilitate experimental approaches aimed at identifying the regulatory mechanisms underlying Hox expression in Time and Space. PMID:25602523

Can a genetically-modified organism-containing diet influence embryo development? A preliminary study on pre-implantation mouse embryos.

PubMed

Cisterna, B; Flach, F; Vecchio, L; Barabino, S M L; Battistelli, S; Martin, T E; Malatesta, M; Biggiogera, M

2008-01-01

In eukaryotic cells, pre-mRNAs undergo several transformation steps to generate mature mRNAs. Recent studies have demonstrated that a diet containing a genetically modified (GM) soybean can induce modifications of nuclear constituents involved in RNA processing in some tissues of young, adult and old mice. On this basis, we have investigated the ultrastructural and immunocytochemical features of pre-implantation embryos from mice fed either GM or non- GM soybean in order to verify whether the parental diet can affect the morpho-functional development of the embryonic ribonucleoprotein structural constituents involved in pre-mRNA pathways. Morphological observations revealed that the general aspect of embryo nuclear components is similar in the two experimental groups. However, immunocytochemical and in situ hybridization results suggest a temporary decrease of pre-mRNA transcription and splicing in 2-cell embryos and a resumption in 4-8-cell embryos from mice fed GM soybean; moreover, pre-mRNA maturation seems to be less efficient in both 2-cell and 4-8-cell embryos from GM-fed mice than in controls. Although our results are still preliminary and limited to the pre-implantation phases, the results of this study encourage deepening on the effects of food components and/or contaminants on embryo development.

In Vitro Ovule Cultivation for Live-cell Imaging of Zygote Polarization and Embryo Patterning in Arabidopsis thaliana.

PubMed

Kurihara, Daisuke; Kimata, Yusuke; Higashiyama, Tetsuya; Ueda, Minako

2017-09-11

In most flowering plants, the zygote and embryo are hidden deep in the mother tissue, and thus it has long been a mystery of how they develop dynamically; for example, how the zygote polarizes to establish the body axis and how the embryo specifies various cell fates during organ formation. This manuscript describes an in vitro ovule culture method to perform live-cell imaging of developing zygotes and embryos of Arabidopsis thaliana. The optimized cultivation medium allows zygotes or early embryos to grow into fertile plants. By combining it with a poly(dimethylsiloxane) (PDMS) micropillar array device, the ovule is held in the liquid medium in the same position. This fixation is crucial to observe the same ovule under a microscope for several days from the zygotic division to the late embryo stage. The resulting live-cell imaging can be used to monitor the real-time dynamics of zygote polarization, such as nuclear migration and cytoskeleton rearrangement, and also the cell division timing and cell fate specification during embryo patterning. Furthermore, this ovule cultivation system can be combined with inhibitor treatments to analyze the effects of various factors on embryo development, and with optical manipulations such as laser disruption to examine the role of cell-cell communication.

Radial extracorporeal shock wave treatment harms developing chicken embryos

PubMed Central

Kiessling, Maren C.; Milz, Stefan; Frank, Hans-Georg; Korbel, Rüdiger; Schmitz, Christoph

2015-01-01

Radial extracorporeal shock wave treatment (rESWT) has became one of the best investigated treatment modalities for cellulite, including the abdomen as a treatment site. Notably, pregnancy is considered a contraindication for rESWT, and concerns have been raised about possible harm to the embryo when a woman treated with rESWT for cellulite is not aware of her pregnancy. Here we tested the hypothesis that rESWT may cause serious physical harm to embryos. To this end, chicken embryos were exposed in ovo to various doses of radial shock waves on either day 3 or day 4 of development, resembling the developmental stage of four- to six-week-old human embryos. We found a dose-dependent increase in the number of embryos that died after radial shock wave exposure on either day 3 or day 4 of development. Among the embryos that survived the shock wave exposure a few showed severe congenital defects such as missing eyes. Evidently, our data cannot directly be used to draw conclusions about potential harm to the embryo of a pregnant woman treated for cellulite with rESWT. However, to avoid any risks we strongly recommend applying radial shock waves in the treatment of cellulite only if a pregnancy is ruled out. PMID:25655309

High-frequency plant regeneration through cyclic secondary somatic embryogenesis in black pepper (Piper nigrum L.).

PubMed

Nair, R Ramakrishnan; Dutta Gupta, S

2006-01-01

A high-frequency plantlet regeneration protocol was developed for black pepper (Piper nigrum L.) through cyclic secondary somatic embryogenesis. Secondary embryos formed from the radicular end of the primary somatic embryos which were originally derived from micropylar tissues of germinating seeds on growth regulator-free SH medium in the absence of light. The process of secondary embryogenesis continued in a cyclic manner from the root pole of newly formed embryos resulting in clumps of somatic embryos. Strength of the medium and sucrose concentration influenced the process of secondary embryogenesis and fresh weight of somatic embryo clumps. Full-strength SH medium supplemented with 1.5% sucrose produced significantly higher fresh weight and numbers of secondary somatic embryos while 3.0 and 4.5% sucrose in the medium favored further development of proliferated embryos into plantlets. Ontogeny of secondary embryos was established by histological analysis. Secondary embryogenic potential was influenced by the developmental stage of the explanted somatic embryo and stages up to "torpedo" were more suitable. A single-flask system was standardized for proliferation, maturation, germination and conversion of secondary somatic embryos in suspension cultures. The system of cyclic secondary somatic embryogenesis in black pepper described here represents a permanent source of embryogenic material that can be used for genetic manipulations of this crop species.

Effect of early addition of bone morphogenetic protein 5 (BMP5) to embryo culture medium on in vitro development and expression of developmentally important genes in bovine preimplantation embryos.

PubMed

García, Elina V; Miceli, Dora C; Rizo, Gabriela; Valdecantos, Pablo A; Barrera, Antonio D

2015-09-01

Previous studies have reported that bone morphogenetic protein 5 (BMP5) is differentially expressed in the isthmus of bovine oviducts and it is present in the oviductal fluid. However, the specific action of this factor is unknown. To evaluate whether BMP5 exerts some effect during early bovine embryo development, gene expression of BMP5, BMP receptors, and the effect of exogenous BMP5 on in vitro development and expression of developmentally important genes were assessed. In experiment 1, pools of embryos at two-cell, four-cell, eight-cell, and blastocyst stages, derived from in vitro fertilization, were collected for analysis of BMP5 and BMP receptors (BMPR1A, BMPR1B, and BMPR2) messenger RNA (mRNA) expression. On the basis of previous results, in experiment 2, presumptive zygotes were cultured for the first 48 hours after insemination in CR1aa medium assaying three different treatments: (1) control (CR1aa); (2) vehicle control (CR1aa + 0.04 mM HCl), and (3) BMP5 treatment (CR1aa + 100 ng/mL of BMP5). The cleavage rate was evaluated 48 hours after insemination (Day 2), and then, embryos were transferred to CR1aa + 10% fetal bovine serum. The blastocyst rate was determined on Day 7. In experiment 3, pools of embryos at two-cell, four-cell, eight-cell, and blastocyst stages, derived from control and BMP5-treated groups, were collected for analysis of ID2 (BMP target gene), OCT4, NANOG, and SOX2 (pluripotency genes) mRNA expression. BMP5 transcripts were not detectable in any of the embryonic stages examined, whereas the relative mRNA abundance of the three BMP receptors analyzed was greater in early embryo development stages before maternal-embryonic transition, raising the possibility of a direct effect of exogenous BMPs on the embryo during the first developmental period. Although early addition of 100 ng/mL of BMP5 to the embryo culture medium had no effect on the cleavage rate, a significantly higher proportion of cleaved embryos developed to the blastocyst stage in the BMP5 group. Moreover, reverse transcription quantitative real-time polymerase chain reaction analysis showed a significant increase in the relative abundance of SOX2 in two-cell stage embryos, ID2 and OCT4 in eight-cell stage embryos, and NANOG and OCT4 in blastocysts derived from BMP5-treated embryos. In conclusion, our results report that early addition of BMP5 to the embryo culture medium had a positive effect on the blastocyst rate and affected the relative expression of BMP target and pluripotency genes, suggesting that BMP5 could play an important role in the preimplantation development of bovine embryos. Copyright © 2015 Elsevier Inc. All rights reserved.

Supplementation with CTGF, SDF1, NGF, and HGF promotes ovine in vitro oocyte maturation and early embryo development.

PubMed

Wang, D H; Ren, J; Zhou, C J; Han, Z; Wang, L; Liang, C G

2018-05-17

The strategies for improving the in vitro maturation (IVM) of domestic animal oocytes focus on promoting nuclear and cytoplasmic maturation. The identification of paracrine factors and their supplementation in the culture medium represent effective approaches for oocyte maturation and embryo development. This study investigated the effects of paracrine factor supplementation including connective tissue growth factor (CTGF), nerve growth factor (NGF), hepatocyte growth factor (HGF), and stromal derived factor 1 (SDF1) on ovine oocytes and early parthenogenetic embryos using an in vitro culture system. First, we identified the optimal concentrations of CTGF (30 ng/mL), SDF1 (10 ng/mL), NGF (3 ng/mL), and HGF (100 ng/mL) for promoting oocyte maturation, which combined, induced nuclear maturation in 94.19% of oocytes. This combination also promoted cumulus cell expansion and inhibited oocyte/cumulus apoptosis, while enabling a larger proportion (33.04%) of embryos to develop into blastocysts than in the controls and prevented embryo apoptosis. These novel findings demonstrate that the paracrine factors CTGF, SDF1, NGF, and HGF facilitate ovine oocyte and early parthenogenetic embryo development in vitro. Thus, supplementation with these factors may help optimize the IVM of ovine oocytes and early parthenogenetic embryo development strategies. Copyright © 2018 Elsevier Inc. All rights reserved.

Femtosecond laser surgery of two-cell mouse embryos: effect on viability, development, and tetraploidization

NASA Astrophysics Data System (ADS)

Osychenko, Alina A.; Zalessky, Alexandr D.; Kostrov, Andrey N.; Ryabova, Anastasia V.; Krivokharchenko, Alexander S.; Nadtochenko, Viktor A.

2017-12-01

The effect of the laser pulse energy and total expose of the energy incident on the embryo blastomere fusion probability was investigated. The probability of the four different events after laser pulse was determined: the fusion of two blastomeres with the following formation of tetraploid embryo, the destruction of the first blastomere occurs, the second blastomere conservation remains intact, the destruction and the death of both cells; two blastomeres were not fused, and no morphological changes occurred. We report on viability and quality of the embryo after laser surgery as a function of the laser energy incident. To characterize embryo quality, the probability of the blastocyst stage achievement was estimated and the blastocyst cells number was calculated. Blastocoel formation is the only event of morphogenesis in the preimplantation development of mammals, so we assumed it as an indicator of the time of embryonic "clocks" and observed it among fused and control embryos. The blastocoel formation time is the same for fused and control embryos. It indicates that embryo clocks were not affected due to blastomere fusion. Thus, the analysis of the fluorescence microscopic images of nuclei in the fused embryo revealed that nuclei fusion does not occur after blastomere fusion.

Adjustments in cholinergic, adrenergic and purinergic control of cardiovascular function in snapping turtle embryos (Chelydra serpentina) incubated in chronic hypoxia.

PubMed

Eme, John; Rhen, Turk; Crossley, Dane A

2014-10-01

Adenosine is an endogenous nucleoside that acts via G-protein coupled receptors. In vertebrates, arterial or venous adenosine injection causes a rapid and large bradycardia through atrioventricular node block, a response mediated by adenosine receptors that inhibit adenylate cyclase and decrease cyclic AMP concentration. Chronic developmental hypoxia has been shown to alter cardioregulatory mechanisms in reptile embryos, but adenosine's role in mediating these responses is not known. We incubated snapping turtle embryos under chronic normoxic (N21; 21 % O2) or chronic hypoxic conditions (H10; 10 % O2) beginning at 20 % of embryonic incubation. H10 embryos at 90 % of incubation were hypotensive relative to N21 embryos in both normoxic and hypoxic conditions. Hypoxia caused a hypotensive bradycardia in both N21 and H10 embryos during the initial 30 min of exposure; however, f H and P m both trended towards increasing during the subsequent 30 min, and H10 embryos were tachycardic relative to N21 embryos in hypoxia. Following serial ≥1 h exposure to normoxic and hypoxic conditions, a single injection of adenosine (1 mg kg(-1)) was given. N21 and H10 embryos responded to adenosine injection with a rapid and large hypotensive bradycardia in both normoxia and hypoxia. Gene expression for adenosine receptors were quantified in cardiac tissue, and Adora1 mRNA was the predominant receptor subtype with transcript levels 30-82-fold higher than Adora2A or Adora2B. At 70 % of incubation, H10 embryos had lower Adora1 and Adora2B expression compared to N21 embryos. Expression of Adora1 and Adora2B decreased in N21 embryos during development and did not differ from H10 embryos at 90 % of incubation. Similar to previous results in normoxia, H10 embryos in hypoxia were chronically tachycardic compared to N21 embryos before and after complete cholinergic and adrenergic blockade. Chronic hypoxia altered the development of normal cholinergic and adrenergic tone, as well as adenosine receptor mRNA levels. This study demonstrates that adenosine may be a major regulator of heart rate in developing snapping turtle embryos, and that chronic hypoxic incubation alters the response to hypoxic exposure.

Early detection and staging of spontaneous embryo resorption by ultrasound biomicroscopy in murine pregnancy

PubMed Central

2014-01-01

Background Embryo resorption is a major problem in human medicine, agricultural animal production and in conservation breeding programs. Underlying mechanisms have been investigated in the well characterised mouse model. However, post mortem studies are limited by the rapid disintegration of embryonic structures. A method to reliably identify embryo resorption in alive animals has not been established yet. In our study we aim to detect embryos undergoing resorption in vivo at the earliest possible stage by ultra-high frequency ultrasound. Methods In a longitudinal study, we monitored 30 pregnancies of wild type C57BI/6 mice using ultra-high frequency ultrasound (30-70 MHz), so called ultrasound biomicroscopy (UBM). We compared the sonoembryology of mouse conceptuses under spontaneous resorption and neighbouring healthy conceptuses and correlated the live ultrasound data with the respective histology. Results The process of embryo resorption comprised of four stages: first, the conceptus exhibited growth retardation, second, bradycardia and pericardial edema were observed, third, further development ceased and the embryo died, and finally embryo remnants were resorbed by maternal immune cells. In early gestation (day 7 and 8), growth retardation was characterized by a small embryonic cavity. The embryo and its membranes were ill defined or did not develop at all. The echodensity of the embryonic fluid increased and within one to two days, the embryo and its cavity disappeared and was transformed into echodense tissue surrounded by fluid filled caverns. In corresponding histologic preparations, fibrinoid material interspersed with maternal granulocytes and lacunae filled with maternal blood were observed. In later stages (day 9–11) resorption prone embryos were one day behind in their development compared to their normal siblings. The space between Reichert’s membrane and inner yolk sac membrane was enlarged The growth retarded embryos exhibited bradycardia and ultimately cessation of heart beat. Corresponding histology showed apoptotic cells in the embryo while the placenta was still intact. In the subsequent resorption process first the embryo and then its membranes disappeared. Conclusions Our results provide a temporal time course of embryo resorption. With this method, animals exhibiting embryo resorption can be targeted, enabling the investigation of underlying mechanisms before the onset of total embryo disintegration. PMID:24886361

Biosensors for detecting stress in developing embryos

NASA Astrophysics Data System (ADS)

Purdey, Malcolm S.; Saini, Avishkar; McLennan, Hanna J.; Pullen, Benjamin J.; Schartner, Erik P.; Sutton-McDowall, Melanie L.; Thompson, Jeremy G.; Monro, Tanya M.; Nicholls, Stephen J.; Abell, Andrew D.

2016-12-01

Reactive Oxygen Species (ROS) cause DNA damage and defective function in sperm and also affects the developmental competence of embryos. It is therefore critical to monitor ROS in sperm, oocytes and developing embryos. In particular, hydrogen peroxide (H2O2) is a ROS important to normal cell function and signalling as well as its role in oxidative stress. Here we report the development of a fluorescent sensor for H2O2 using carboxyperoxyfluor-1 (CPF1) in solution and attached to a glass slide or multi-mode optical fibre. CPF1 increases in fluorescence upon reaction with H2O2 to non-invasively detect H2O2 near developing embryos. These probes are constructed by immobilising CPF1 to the optical fibre tip a polyacrylamide layer. Also reported is a new dual optical fibre sensor for detecting both H2O2 and pH that is functional at biologically concentrations of H2O2 and can sense pH to 0.1 units. This research shows promise for the use of optical fibre sensors for monitoring the health of developing embryos. Furthermore, these sensors are applicable for use beyond embryos such as detecting stress in endothelial cells involved in cardiovascular dysfunction.

Effect of postactivation treatment with latrunculin A on in vitro and in vivo development of cloned embryos derived from kidney fibroblasts of an aged Clawn miniature boar.

PubMed

Himaki, Takehiro; Mizobe, Yamato; Tsuda, Kenichirou; Suetomo, Masashi; Yamakuchi, Hiroshi; Miyoshi, Kazuchika; Takao, Sonshin; Yoshida, Mitsutoshi

2012-01-01

The objective of this study was to examine the effect of postactivation treatment with latrunculin A (LatA), an actin polymerization inhibitor, on in vitro and in vivo development of somatic cell nuclear transfer (SCNT) embryos derived from kidney fibroblasts of an aged Clawn miniature boar (12 years old). After electric activation, SCNT embryos were treated with 0, 0.5 or 1 μM LatA and cultured in vitro. The rate of blastocyst formation was significantly higher (P<0.05) in SCNT embryos treated with 0.5 μM LatA (38%) than those in control (14%). When cloned embryos treated with 0.5 μM LatA were transferred into the oviducts of two recipient miniature gilts to assess their development in vivo, both recipients became pregnant; one maintained pregnancy to term, and a live piglet (weighing 220 g) was delivered by Caesarean section. The results of this study indicated that the postactivation treatment with LatA was effective in improving in vitro developmental capacity of SCNT miniature pig embryos derived from kidney fibroblasts of an aged animal and that miniature pig cloned embryos treated with LatA had the ability to develop to term.

Effects of the popular food additive sodium benzoate on neural tube development in the chicken embryo.

PubMed

Emon, Selin Tural; Orakdogen, Metin; Uslu, Serap; Somay, Hakan

2015-01-01

Many more additives have been introduced with the development of processed foods. Neural tube defects are congenital malformations of the central nervous system. More than 300 000 children are born with neural tube defects every year and surviving children remain disabled for life. Sodium benzoate is used intensively in our daily lives. We therefore aimed to evaluate the effects of sodium benzoate on neural tube defects in chicken embryos. Fertile, specific pathogen-free eggs were used. The study was conducted on five groups. After 30 hours of incubation, the eggs were opened under 4x optical magnification. The embryonic disc was identified and sodium benzoate solution was injected. Eggs were closed with sterile adhesive strips and incubation was continued till the end of the 72nd hour. All eggs were then reopened and embryos were dissected from embryonic membranes and evaluated histopathologically. We found that the development of all embryos was consistent with the stage. We detected neural tube obstruction in one embryo. Neural tube defects were not detected in any embryos. This study showed that sodium benzoate as one of the widely used food preservatives has no effect to neural tube defect development in chicken embryos even at high doses.

Breeding for seedless grapes using Chinese wild Vitis spp. II. In vitro embryo rescue and plant development.

PubMed

Ji, Wei; Wang, Yuejin

2013-12-01

Since 1982, the embryo rescue technique has been widely applied to embryo germination of stenospermic grapes in cross-breeding programmes. This project aimed to: (1) use embryos to breed new seedless cultivars of Vitis vinifera as the female parents utilising wild Chinese Vitis spp. as the male parents; and (2) develop an efficient method for in vitro embryo rescue and plant development. Among the different genotypes, the productions of hybrid plants were significantly different, ranged from 21.1% ('Ruby Seedless' × 'Beichun') to only 1.1% ('Pink Seedless' × 'Beichun'), except for the combinations from which no surviving seedlings were obtained. We collected hybridisation fruits from 28 June to 3 August, and obtained their best sampling times described within days after flowering. The highest rates of embryo formation (24.3%) and plant development (91.4%) were found when ovules of 'Ruby Seedless' were cultured in MM4 + 500 mg L(-1) mashed banana. Seven new hybrids of V. vinifera with wild Chinese Vitis spp. were obtained. As a result of early nuclear-free character identification, 17 seedless grape lines were obtained. An efficient system of seedless grape breeding through embryo rescue was also established. © 2013 Society of Chemical Industry.

Hypoxic alligator embryos: chronic hypoxia, catecholamine levels and autonomic responses of in ovo alligators.

PubMed

Eme, John; Altimiras, Jordi; Hicks, James W; Crossley, Dane A

2011-11-01

Hypoxia is a naturally occurring environmental challenge for embryonic reptiles, and this is the first study to investigate the impact of chronic hypoxia on the in ovo development of autonomic cardiovascular regulation and circulating catecholamine levels in a reptile. We measured heart rate (f(H)) and chorioallantoic arterial blood pressure (MAP) in normoxic ('N21') and hypoxic-incubated ('H10'; 10% O(2)) American alligator embryos (Alligator mississippiensis) at 70, 80 and 90% of development. Embryonic alligator responses to adrenergic blockade with propranolol and phentolamine were very similar to previously reported responses of embryonic chicken, and demonstrated that embryonic alligator has α and β-adrenergic tone over the final third of development. However, adrenergic tone originates entirely from circulating catecholamines and is not altered by chronic hypoxic incubation, as neither cholinergic blockade with atropine nor ganglionic blockade with hexamethonium altered baseline cardiovascular variables in N21 or H10 embryos. In addition, both atropine and hexamethonium injection did not alter the generally depressive effects of acute hypoxia - bradycardia and hypotension. However, H10 embryos showed significantly higher levels of noradrenaline and adrenaline at 70% of development, as well as higher noradrenaline at 80% of development, suggesting that circulating catecholamines reach maximal levels earlier in incubation for H10 embryos, compared to N21 embryos. Chronically elevated levels of catecholamines may alter the normal balance between α and β-adrenoreceptors in H10 alligator embryos, causing chronic bradycardia and hypotension of H10 embryos measured in normoxia. Copyright © 2011 Elsevier Inc. All rights reserved.

Absence of nucleolus formation in raccoon dog-porcine interspecies somatic cell nuclear transfer embryos results in embryonic developmental failure.

PubMed

Jeon, Yubyeol; Nam, Yeong-Hee; Cheong, Seung-A; Kwak, Seong-Sung; Lee, Eunsong; Hyun, Sang-Hwan

2016-08-25

Interspecies somatic cell nuclear transfer (iSCNT) can be a solution for preservation of endangered species that have limited oocytes. It has been reported that blastocyst production by iSCNT is successful even if the genetic distances between donors and recipients are large. In particular, domestic pig oocytes can support the development of canine to porcine iSCNT embryos. Therefore, we examined whether porcine oocytes may be suitable recipient oocytes for Korean raccoon dog iSCNT. We investigated the effects of trichostatin A (TSA) treatment on iSCNT embryo developmental patterns and nucleolus formation. Enucleated porcine oocytes were fused with raccoon dog fibroblasts by electrofusion and cleavage, and blastocyst development and nucleolus formation were evaluated. To our knowledge, this study is the first in which raccoon dog iSCNT was performed using porcine oocytes; we found that 68.5% of 158 iSCNT embryos had the ability to cleave. However, these iSCNT embryos did not develop past the 4-cell stage. Treatment with TSA did not affect iSCNT embryonic development; moreover, the nuclei failed to form nucleoli at 48 and 72 h post-activation (hpa). In contrast, pig SCNT embryos of the control group showed 18.8% and 87.9% nucleolus formation at 48 and 72 hpa, respectively. Our results demonstrated that porcine cytoplasts efficiently supported the development of raccoon dog iSCNT embryos to the 4-cell stage, the stage of porcine embryonic genome activation (EGA); however, these embryos failed to reach the blastocyst stage and showed defects in nucleolus formation.

Micro-magnetic resonance imaging study of live quail embryos during embryonic development.

PubMed

Duce, Suzanne; Morrison, Fiona; Welten, Monique; Baggott, Glenn; Tickle, Cheryll

2011-01-01

Eggs containing live Japanese quail embryos were imaged using micro-magnetic resonance imaging (μMRI) at 24-h intervals from Day 0 to 8, the period during which the main body axis is being laid down and organogenesis is taking place. Considerable detail of non-embryonic structures such as the latebra was revealed at early stages but the embryo could only be visualized around Day 3. Three-dimensional (3D) changes in embryo length and volume were quantified and also changes in volume in the extra- and non-embryonic components. The embryo increased in length by 43% and nearly trebled in volume between Day 4 and Day 5. Although the amount of yolk remained fairly constant over the first 5 days, the amount of albumen decreases significantly and was replaced by extra-embryonic fluid (EEF). ¹H longitudinal (T₁) and transverse (T₂) relaxation times of different regions within the eggs were determined over the first 6 days of development. The T₂ measurements mirrored the changes in image intensity observed, which can be related to the aqueous protein concentrations. In addition, a comparison of the development of Day 0 to 3 quail embryos exposed to radiofrequency (rf) pulses, 7 T static magnetic fields and magnetic field gradients for an average of 7 h with the development of control embryos did not reveal any gross changes, thus confirming that μMRI is a suitable tool for following the development of live avian embryos over time from the earliest stages. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of multi-well plate incubation on embryo-larval development in the fathead minnow (Pimephales promelas).

PubMed

Marentette, Julie R; Sullivan, Cheryl A; Lavalle, Christine; Shires, Kallie; Parrott, Joanne L

2015-01-01

Fathead minnow embryos and larvae are frequently used in toxicology, including short-term embryo-only tests which often use small volumes of test solution. The effect that such conditions may have on fathead minnow development has yet to be explicitly described. Here we compared rates of embryonic development in fathead minnow embryos reared under standard light and temperature conditions with a range of possible methods. All methods yielded excellent control survival. We demonstrated that fathead minnow embryos incubated in a range of small volumes in multi-well plates (500 μL to 2 mL per embryo) did not substantially vary in developmental rate, but flexed less frequently as embryos, hatched smaller, later and with larger yolk-sacs, and initiated feeding later than embryos reared in an excess of solution (20 mL per embryo) with or without supplemental aeration. Faster hatch and growth were promoted with an orbital shaker, but growth benefits were not sustained into the larval stage. Developmental differences persisted in larvae reared to 20 days post-fertilization when monitoring ceased, but growth differences did not magnify and in some measurements partially resolved. To our knowledge we are the first to report effects of incubation in multi-well plates in any fish taxa. As our data revealed that the eleutheroembryonic stage for fathead minnow may be prolonged in multi-well plates, this may allow the use of longer toxicity tests using fathead minnow embryos without conflicting with existing animal welfare legislation in many countries. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Histone Deacetylase Inhibitor Improves the Development and Acetylation Levels of Cat–Cow Interspecies Cloned Embryos

PubMed Central

Wittayarat, Manita; Sato, Yoko; Do, Lanh Thi Kim; Morita, Yasuhiro; Chatdarong, Kaywalee; Techakumphu, Mongkol; Taniguchi, Masayasu

2013-01-01

Abstract Abnormal epigenetic reprogramming, such as histone acetylation, might cause low efficiency of interspecies somatic cell nuclear transfer (iSCNT). This study was conducted to evaluate the effects of trichostatin A (TSA) on the developmental competence and histone acetylation of iSCNT embryos reconstructed from cat somatic cells and bovine cytoplasm. The iSCNT cat and parthenogenetic bovine embryos were treated with various concentrations of TSA (0, 25, 50, or 100 nM) for 24 h, respectively, following fusion and activation. Treatment with 50 nM TSA produced significantly higher rates of cleavage and blastocyst formation (84.3% and 4.6%, respectively) of iSCNT embryos than the rates of non-TSA–treated iSCNT embryos (63.8% and 0%, respectively). Similarly, the treatment of 50 nM TSA increased the blastocyst formation rate of parthenogenetic bovine embryos. The acetylation levels of histone H3 lysine 9 (H3K9) in the iSCNT embryos with the treatment of 50 nM TSA were similar to those of in vitro–fertilized embryos and significantly higher (p<0.05) than those of non-TSA–treated iSCNT embryos (control), irrespective of the embryonic development stage (two-cell, four-cell, and eight-cell stages). These results indicated that the treatment of 50 nM TSA postfusion was beneficial for development to the blastocyst stage of iSCNT cat embryos and correlated with the increasing levels of acetylation at H3K9. PMID:23790014

Alteration of development and gene expression induced by in ovo-nanoinjection of 3-hydroxybenzo[c]phenanthrene into Japanese medaka (Oryzias latipes) embryos.

PubMed

Chen, Kun; Tsutsumi, Yuki; Yoshitake, Shuhei; Qiu, Xuchun; Xu, Hai; Hashiguchi, Yasuyuki; Honda, Masato; Tashiro, Kosuke; Nakayama, Kei; Hano, Takeshi; Suzuki, Nobuo; Hayakawa, Kazuichi; Shimasaki, Yohei; Oshima, Yuji

2017-01-01

Benzo[c]phenanthrene (BcP) is a highly toxic polycyclic aromatic hydrocarbon (PAHs) found throughout the environment. In fish, it is metabolized to 3-hydroxybenzo[c]phenanthrene (3-OHBcP). In the present study, we observed the effects of 1nM 3-OHBcP on the development and gene expression of Japanese medaka (Oryzias latipes) embryos. Embryos were nanoinjected with the chemical after fertilization. Survival, developmental stage, and heart rate of the embryos were observed, and gene expression differences were quantified by messenger RNA sequencing (mRNA-Seq). The exposure to 1nM 3-OHBcP accelerated the development of medaka embryos on the 1st, 4th, and 6th days post fertilization (dpf), and increased heart rates significantly on the 5th dpf. Physical development differences of exposed medaka embryos were consistent with the gene expression profiles of the mRNA-Seq results for the 3rd dpf, which show that the expression of 780 genes differed significantly between the solvent control and 1nM 3-OHBcP exposure groups. The obvious expression changes in the exposure group were found for genes involved in organ formation (eye, muscle, heart), energy supply (ATPase and ATP synthase), and stress-response (heat shock protein genes). The acceleration of development and increased heart rate, which were consistent with the changes in mRNA expression, suggested that 3-OHBcP affects the development of medaka embryos. The observation on the developmental stages and heart beat, in ovo-nanoinjection and mRNA-Seq may be efficient tools to evaluate the effects of chemicals on embryos. Copyright © 2016 Elsevier B.V. All rights reserved.

Dissection and lateral mounting of zebrafish embryos: analysis of spinal cord development.

PubMed

Beck, Aaron P; Watt, Roland M; Bonner, Jennifer

2014-02-28

The zebrafish spinal cord is an effective investigative model for nervous system research for several reasons. First, genetic, transgenic and gene knockdown approaches can be utilized to examine the molecular mechanisms underlying nervous system development. Second, large clutches of developmentally synchronized embryos provide large experimental sample sizes. Third, the optical clarity of the zebrafish embryo permits researchers to visualize progenitor, glial, and neuronal populations. Although zebrafish embryos are transparent, specimen thickness can impede effective microscopic visualization. One reason for this is the tandem development of the spinal cord and overlying somite tissue. Another reason is the large yolk ball, which is still present during periods of early neurogenesis. In this article, we demonstrate microdissection and removal of the yolk in fixed embryos, which allows microscopic visualization while preserving surrounding somite tissue. We also demonstrate semipermanent mounting of zebrafish embryos. This permits observation of neurodevelopment in the dorso-ventral and anterior-posterior axes, as it preserves the three-dimensionality of the tissue.

Dissection and Lateral Mounting of Zebrafish Embryos: Analysis of Spinal Cord Development

PubMed Central

Beck, Aaron P.; Watt, Roland M.; Bonner, Jennifer

2014-01-01

The zebrafish spinal cord is an effective investigative model for nervous system research for several reasons. First, genetic, transgenic and gene knockdown approaches can be utilized to examine the molecular mechanisms underlying nervous system development. Second, large clutches of developmentally synchronized embryos provide large experimental sample sizes. Third, the optical clarity of the zebrafish embryo permits researchers to visualize progenitor, glial, and neuronal populations. Although zebrafish embryos are transparent, specimen thickness can impede effective microscopic visualization. One reason for this is the tandem development of the spinal cord and overlying somite tissue. Another reason is the large yolk ball, which is still present during periods of early neurogenesis. In this article, we demonstrate microdissection and removal of the yolk in fixed embryos, which allows microscopic visualization while preserving surrounding somite tissue. We also demonstrate semipermanent mounting of zebrafish embryos. This permits observation of neurodevelopment in the dorso-ventral and anterior-posterior axes, as it preserves the three-dimensionality of the tissue. PMID:24637734

Effect of alcohol exposure on fetal brain development

NASA Astrophysics Data System (ADS)

Sudheendran, Narendran; Bake, Shameena; Miranda, Rajesh C.; Larin, Kirill V.

2013-02-01

Alcohol consumption during pregnancy can be severely damage to the brain development in fetuses. This study investigates the effects of maternal ethanol consumption on brain development in mice embryos. Pregnant mice at gestational day 12.5 were intragastrically gavaged with ethanol (3g/Kg bwt) twice daily for three consecutive days. On gestational day 14.5, fetuses were collected and fixed in 4% paraformaldehyde and imaged using a swept-source optical coherence tomography (SSOCT) system. 3D images of the mice embryo brain were obtained and the volumes of the left and right ventricles of the brain were measured. The average volumes of the left and the right volumes of 5 embryos each alcohol-exposed and control embryos were measured to be 0.35 and 0.15 mm3, respectively. The results suggest that the left and right ventricle volumes of brain are much larger in the alcohol-exposed embryos as compared to control embryos indicating alcohol-induced developmental delay.

Near-infrared laser irradiation improves the development of mouse pre-implantation embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokoo, Masaki; Mori, Miho

The aim of the present study was to assess the effects of near-infrared laser irradiation on the in vitro development of mouse embryos. Female ICR mice were superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin (hCG), and mated with male mice. Two-cell stage embryos were collected 40 h after administering hCG and cultured in M16 medium. Two-cell embryos (0 h after culture), 8-cell embryos (approx. 30 h after culture), morula (approx. 48 h after culture), and blastocysts (approx. 73 h after culture) were irradiated at 904 nm for 60 s. These embryos were cultured in a time-lapse monitoring system and the timing ofmore » blastocyst hatching was evaluated. Some of the irradiated blastocysts were transferred to the uterine horns of pseudopregnant recipients immediately after irradiation. Pregnancy rates, and offspring growth and fertility, were evaluated. Near-infrared laser irradiation increased the speed of in vitro mouse embryo development. In irradiated blastocysts, hatching was faster than in control (non-irradiated) blastocysts (18.4 vs. 28.2 h, P < 0.05). When 195 irradiated blastocysts were transferred to 18 pseudopregnant mice, all became pregnant and 92 (47.2%) normal-looking pups were born alive. When 182 control blastocysts were transferred to 17 pseudopregnant mice, 14 (82.4%) became pregnant and 54 (29.7%) normal-looking pups were born alive. The growth trajectories (up to 5 weeks) of offspring from irradiated blastocysts were similar to those from control blastocysts. Second generation offspring from transplanted animals were all fertile. These results indicate that near-infrared laser irradiation improves the quality of mouse embryo development in vitro, and increases the live birth rate without affecting the normality of the offspring. Thus, the near-infrared laser method may enhance the quality of embryos and contribute to improvements in reproductive technologies in mammals. - Highlights: • Irradiation of blastocysts with a near-infrared laser improves embryo development. • Irradiation of blastocysts increases the live birth rate after embryo transfer. • Irradiation of blastocysts did not affect the normality of the pups. • Near-infrared laser irradiation may be useful to enhance the quality of embryos. • This study may contribute to improvements in reproductive technologies in mammals.« less

Preimplantation development of somatic cell cloned embryos in the common marmoset (Callithrix jacchus).

PubMed

Sotomaru, Yusuke; Hirakawa, Reiko; Shimada, Akiko; Shiozawa, Seiji; Sugawara, Ayako; Oiwa, Ryo; Nobukiyo, Asako; Okano, Hideyuki; Tamaoki, Norikazu; Nomura, Tatsuji; Hiyama, Eiso; Sasaki, Erika

2009-12-01

The somatic cell nuclear transfer technique has been applied to various mammals to produce cloned animals; however, a standardized method is not applicable to all species. We aimed here to develop optimum procedures for somatic cell cloning in nonhuman primates, using common marmosets. First, we confirmed that parthenogenetic activation of in vitro matured oocytes was successfully induced by electrical stimulation (three cycles of 150 V/mm, 50 microsec x 2, 20 min intervals), and this condition was applied to the egg activation procedure in the subsequent experiments. Next, nuclear transfer to recipient enucleated oocytes was performed 1 h before, immediately after, or 1 h after egg activation treatment. The highest developmental rate was observed when nuclear transfer was performed 1 h before activation, but none of the cloned embryos developed beyond the eight-cell stage. To investigate the causes of the low developmental potential of cloned embryos, a study was performed to determine whether the presence of metaphase II (MII) chromosome in recipient ooplasm has an effect on developmental potential. As a result, only tetraploid cloned embryos produced by transferring a donor cell into a recipient bearing the MII chromosome developed into blastocysts (66.7%). In contrast, neither parthenogenetic embryos nor cloned embryos (whether diploid or tetraploid) produced using enucleated oocytes developed past the eight-cell stage. These results suggest that MII chromosome, or cytoplasm proximal to the MII chromosome, plays a major role in the development of cloned embryos in common marmosets.

Rapid and simple method for in vivo ex utero development of mouse embryo explants.

PubMed

Gonçalves, André B; Thorsteinsdóttir, Sólveig; Deries, Marianne

2016-01-01

The in utero development of mammals drastically reduces the accessibility of the mammalian embryo and therefore limits the range of experimental manipulation that can be done to study functions of genes or signaling pathways during embryo development. Over the past decades, tissue and organ-like culture methods have been developed with the intention of reproducing in vivo situations. Developing accessible and simple techniques to study and manipulate embryos is an everlasting challenge. Herein, we describe a reliable and quick technique to culture mid-gestation explanted mouse embryos on top of a floating membrane filter in a defined medium. Viability of the cultured tissues was assessed by apoptosis and proliferation analysis showing that cell proliferation is normal and there is only a slight increase in apoptosis after 12h of culture compared to embryos developing in utero. Moreover, differentiation and morphogenesis proceed normally as assessed by 3D imaging of the transformation of the myotome into deep back muscles. Not only does muscle cell differentiation occur as expected, but so do extracellular matrix organization and the characteristic splitting of the myotome into the three epaxial muscle groups. Our culture method allows for the culture and manipulation of mammalian embryo explants in a very efficient way, and it permits the manipulation of in vivo developmental events in a controlled environment. Explants grown under these ex utero conditions simulate real developmental events that occur in utero. Copyright © 2016 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

Commonly used fertility drugs, a diet supplement, and stress force AMPK-dependent block of stemness and development in cultured mammalian embryos.

PubMed

Bolnick, Alan; Abdulhasan, Mohammed; Kilburn, Brian; Xie, Yufen; Howard, Mindie; Andresen, Paul; Shamir, Alexandra M; Dai, Jing; Puscheck, Elizabeth E; Rappolee, Daniel A

2016-08-01

The purpose of the present study is to test whether metformin, aspirin, or diet supplement (DS) BioResponse-3,3'-Diindolylmethane (BR-DIM) can induce AMP-activated protein kinase (AMPK)-dependent potency loss in cultured embryos and whether metformin (Met) + Aspirin (Asa) or BR-DIM causes an AMPK-dependent decrease in embryonic development. The methods used were as follows: culture post-thaw mouse zygotes to the two-cell embryo stage and test effects after 1-h AMPK agonists' (e.g., Met, Asa, BR-DIM, control hyperosmotic stress) exposure on AMPK-dependent loss of Oct4 and/or Rex1 nuclear potency factors, confirm AMPK dependence by reversing potency loss in two-cell-stage embryos with AMPK inhibitor compound C (CC), test whether Met + Asa (i.e., co-added) or DS BR-DIM decreases development of two-cell to blastocyst stage in an AMPK-dependent (CC-sensitive) manner, and evaluate the level of Rex1 and Oct4 nuclear fluorescence in two-cell-stage embryos and rate of two-cell-stage embryo development to blastocysts. Met, Asa, BR-DIM, or hyperosmotic sorbitol stress induces rapid ~50-85 % Rex1 and/or Oct4 protein loss in two-cell embryos. This loss is ~60-90 % reversible by co-culture with AMPK inhibitor CC. Embryo development from two-cell to blastocyst stage is decreased in culture with either Met + Asa or BR-DIM, and this is either >90 or ~60 % reversible with CC, respectively. These experimental designs here showed that Met-, Asa-, BR-DIM-, or sorbitol stress-induced rapid potency loss in two-cell embryos is AMPK dependent as suggested by inhibition of Rex1 and/or Oct4 protein loss with an AMPK inhibitor. The DS BR-DIM or fertility drugs (e.g., Met + Asa) that are used to enhance maternal metabolism to support fertility can also chronically slow embryo growth and block development in an AMPK-dependent manner.

The effect of soluble uterine factors on porcine embryo development within a three-dimensional alginate matrix system

USDA-ARS?s Scientific Manuscript database

Between day 10 and 12 of gestation in the pig, the embryo undergoes a dramatic morphological change, known as elongation. During elongation the embryo produces and secretes estrogen, which serves as a key signal for maternal recognition of pregnancy. The uterine environment prepares for embryo elong...

Embryotrophic factor-3 from human oviductal cells enhances proliferation, suppresses apoptosis and stimulates the expression of the beta1 subunit of sodium-potassium ATPase in mouse embryos.

PubMed

Xu, J S; Lee, Y L; Lee, K F; Kwok, K L; Lee, W M; Luk, J M; Yeung, W S B

2004-12-01

Embrytrophic factor-3 (ETF-3) from human oviductal cells enhanced the development of mouse preimplantation embryos. This report studied the embryotrophic mechanisms of the molecule. Mouse embryos were incubated with ETF-3 for 24 h at different stages of development. ETF-3 treatment between 96 and 120 h post-HCG increased the cell count of blastocysts, whilst treatment between 72 and 96 h post-HCG enhanced the expansion and hatching of the blastocysts. ETF-3 increased the cell number of the embryos by suppressing apoptosis and increasing proliferation as determined by TUNEL and bromodeoxyuridine uptake assays, respectively. Real-time quantitative PCR showed that the in vivo developed and ETF-3-treated blastocysts had a significantly higher mRNA copy number of Na/K-ATPase-beta1, but not of hepsin, than that of blastocysts cultured in medium alone. The former gene was associated with cavitation of blastocysts while the latter was related to hatching of blastocyst. The beneficial effect of ETF-3 on blastocyst hatching was also seen when ETF-3-supplemented commercially available sequential culture medium for human embryo culture was used to culture mouse embryos. ETF-3 improves embryo development by enhancing proliferation, suppressing apoptosis and stimulating expression of genes related to blastocyst cavitation. Supplementating human embryo culture medium with ETF-3 may improve the success rate in clinical assisted reproduction.

Characteristics of plastids responsible for starch synthesis in developing pea embryos.

PubMed

Smith, A M; Quinton-Tulloch, J; Denyer, K

1990-03-01

The nature of the starch-synthesising plastids in developing pea (Pisum sativum L.) embryos has been investigated. Chlorophyll and starch were distributed throughout the cotyledon during development. Chlorophyll content increased initially, then showed little change up to the point of drying out of the embryo. Starch content per embryo increased dramatically throughout development. The chlorophyll content per unit volume was highest on the outer edge of the cotyledon, while the starch content was highest on inner face. Nycodenz gradients, which fractionated mechanically-prepared plastids according to their starch content, failed to achieve any significant separation of plastids rich in starch and ADP-glucose pyrophosphorylase from those rich in chlorophyll and a Calvin-cycle marker enzyme, NADP-glyceraldehyde-3-phosphate dehydrogenase. However, material that was not sufficiently dense to enter the gradients was enriched in activity of the Calvin-cycle marker enzyme relative to that of ADP-glucose pyrophosphorylase. Nomarski and epi-fluorescence microscopy showed that intact, isolated plastids, including those with very large starch grains, invariably contained chlorophyll in stromal structures peripheral to the starch grain. We suggest that the starch-storing plastids of developing pea embryos are derived directly from chloroplasts, and retain chloroplast-like characteristics throughout their development. Developing pea embryos also contain chloroplasts which store little or no starch. These are probably located primarily on the outer edge of the cotyledons where there is sufficient light for photosynthesis at some stages of development.

Live embryo imaging to follow cell cycle and chromosomes stability after nuclear transfer.

PubMed

Balbach, Sebastian T; Boiani, Michele

2015-01-01

Nuclear transfer (NT) into mouse oocytes yields a transcriptionally and functionally heterogeneous population of cloned embryos. Most studies of NT embryos consider only embryos at predefined key stages (e.g., morula or blastocyst), that is, after the bulk of reprogramming has taken place. These retrospective approaches are of limited use to elucidate mechanisms of reprogramming and to predict developmental success. Observing cloned embryo development using live embryo cinematography has the potential to reveal otherwise undetectable embryo features. However, light exposure necessary for live cell cinematography is highly toxic to cloned embryos. Here we describe a protocol for combined bright-field and fluorescence live-cell imaging of histone H2b-GFP expressing mouse embryos, to record cell divisions up to the blastocyst stage. This protocol, which can be adapted to observe other reporters such as Oct4-GFP or Nanog-GFP, allowed us to quantitatively analyze cleavage kinetics of cloned embryos.

The Roles of Glutathione Peroxidases during Embryo Development

PubMed Central

Ufer, Christoph; Wang, Chi Chiu

2011-01-01

Embryo development relies on the complex interplay of the basic cellular processes including proliferation, differentiation, and apoptotic cell death. Precise regulation of these events is the basis for the establishment of embryonic structures and the organ development. Beginning with fertilization of the oocyte until delivery the developing embryo encounters changing environmental conditions such as varying levels of oxygen, which can give rise to reactive oxygen species (ROS). These challenges are met by the embryo with metabolic adaptations and by an array of anti-oxidative mechanisms. ROS can be deleterious by modifying biological molecules including lipids, proteins, and nucleic acids and may induce abnormal development or even embryonic lethality. On the other hand ROS are vital players of various signaling cascades that affect the balance between cell growth, differentiation, and death. An imbalance or dysregulation of these biological processes may generate cells with abnormal growth and is therefore potentially teratogenic and tumorigenic. Thus, a precise balance between processes generating ROS and those decomposing ROS is critical for normal embryo development. One tier of the cellular protective system against ROS constitutes the family of selenium-dependent glutathione peroxidases (GPx). These enzymes reduce hydroperoxides to the corresponding alcohols at the expense of reduced glutathione. Of special interest within this protein family is the moonlighting enzyme glutathione peroxidase 4 (Gpx4). This enzyme is a scavenger of lipophilic hydroperoxides on one hand, but on the other hand can be transformed into an enzymatically inactive cellular structural component. GPx4 deficiency – in contrast to all other GPx family members – leads to abnormal embryo development and finally produces a lethal phenotype in mice. This review is aimed at summarizing the current knowledge on GPx isoforms during embryo development and tumor development with an emphasis on GPx4. PMID:21847368

The Roles of Glutathione Peroxidases during Embryo Development.

PubMed

Ufer, Christoph; Wang, Chi Chiu

2011-01-01

Embryo development relies on the complex interplay of the basic cellular processes including proliferation, differentiation, and apoptotic cell death. Precise regulation of these events is the basis for the establishment of embryonic structures and the organ development. Beginning with fertilization of the oocyte until delivery the developing embryo encounters changing environmental conditions such as varying levels of oxygen, which can give rise to reactive oxygen species (ROS). These challenges are met by the embryo with metabolic adaptations and by an array of anti-oxidative mechanisms. ROS can be deleterious by modifying biological molecules including lipids, proteins, and nucleic acids and may induce abnormal development or even embryonic lethality. On the other hand ROS are vital players of various signaling cascades that affect the balance between cell growth, differentiation, and death. An imbalance or dysregulation of these biological processes may generate cells with abnormal growth and is therefore potentially teratogenic and tumorigenic. Thus, a precise balance between processes generating ROS and those decomposing ROS is critical for normal embryo development. One tier of the cellular protective system against ROS constitutes the family of selenium-dependent glutathione peroxidases (GPx). These enzymes reduce hydroperoxides to the corresponding alcohols at the expense of reduced glutathione. Of special interest within this protein family is the moonlighting enzyme glutathione peroxidase 4 (Gpx4). This enzyme is a scavenger of lipophilic hydroperoxides on one hand, but on the other hand can be transformed into an enzymatically inactive cellular structural component. GPx4 deficiency - in contrast to all other GPx family members - leads to abnormal embryo development and finally produces a lethal phenotype in mice. This review is aimed at summarizing the current knowledge on GPx isoforms during embryo development and tumor development with an emphasis on GPx4.

Mass production of somatic embryos expressing Escherichia coli heat-labile enterotoxin B subunit in Siberian ginseng.

PubMed

Kang, Tae-Jin; Lee, Won-Seok; Choi, Eun-Gyung; Kim, Jae-Whune; Kim, Bang-Geul; Yang, Moon-Sik

2006-01-24

The B subunit of Escherichia coli heat-labile toxin (LTB) is a potent mucosal immunogen and immunoadjuvant for co-administered antigens. In order to produce large scale of LTB for the development of edible vaccine, we used transgenic somatic embryos of Siberian ginseng, which is known as medicinal plant. When transgenic somatic embryos were cultured in 130L air-lift type bioreactor, they were developed to mature somatic embryos through somatic embryogenesis and contained approximately 0.36% LTB of the total soluble protein. Enzyme-linked immunosorbent assay indicated that the somatic embryo-synthesized LTB protein bound specifically to GM1-ganglioside, suggesting the LTB subunits formed active pentamers. Therefore, the use of the bioreactor system for expression of LTB proteins in somatic embryos allows for continuous mass production in a short-term period.

[Direct and indirect somatic embryogenesis in Freesia refracta].

PubMed

Wang, L; Duan, X G; Hao, S

1999-06-01

Somatic embryogenesis can be induced in tissue cultures of Freesia refracta either directly from the epidermal cells of explant, or indirectly via intervening callus. In direct pathway, somatic embryos were in contact with maternal tissue in a suspensor-like structure. In indirect pathway, the explants first proliferacted to give rise to calluses before embryoids were induced. The two sorts of calluses were defined to embryogenic callus and non-embryogenic callus according to producing of somatic embryos. An indirect somatic embryo is developed from a pre-embryogenically determined cell. This kind of somatic embryo has no suspensor structure instead of a complex with maternal tissue. Somatic embryos have their own vascular tissues, and can develop new plantlets independently.

Facilitated glucose transporters play a crucial role throughout mouse preimplantation embryo development.

PubMed

Leppens-Luisier, G; Urner, F; Sakkas, D

2001-06-01

The role of glucose fluctuates during preimplantation mouse embryo development, indicating that a specific interplay exists between glucose metabolism and uptake. In this study, attempts were made to characterize the role of the Na(+)-coupled active and the facilitated glucose transporters (GLUT) during preimplantation development by using specific glucose analogues and transport inhibitors and by examining the expression of GLUT1. One-cell outbred mouse embryos were cultured in medium M16 (5.5 mmol/l glucose), M16 without glucose (M16-G), M16-G + 2-deoxyglucose, M16-G + 3-O-methylglucose, M16 + phlorizin and M16 + phloretin and development to the blastocyst stage assessed. The absence of glucose, or the presence of 3-O-methylglucose, which is taken up but not metabolized, did not inhibit blastocyst development. 2-Deoxyglucose, which is phosphorylated but not metabolized, inhibited blastocyst development. Culture in M16 supplemented with phlorizin, an inhibitor of Na(+)-coupled active glucose transport did not inhibit blastocyst formation. Phloretin had no effect on the cleavage of two-cell embryos to the four-cell stage, but inhibited the morula/blastocyst transition. Both phloretin and phlorizin inhibited glucose uptake in two-cell embryos. Finally, GLUT1 expression was 10-fold less in blastocysts cultured in M16 compared to in-vivo blastocysts and those cultured in M16-G. The results show that both types of glucose transporters influence preimplantation embryo development and that the embryo has an innate ability to control the uptake of glucose by regulating the expression of GLUT1.

Progress Towards the Development of a Fathead Minnow Embryo Test and Comparison to the Zebrafish Embryo Test for Assessing Acute Fish Toxicity

EPA Science Inventory

The Zebrafish Embryo Test (ZFET) for acute fish toxicity is a well developed method nearing adoption as an OECD Test Guideline. Early drafts of the test guideline (TG) envisioned a suite of potential test species to be covered including zebrafish, fathead minnow, Japanese Medaka...

Determinants of embryo development and quality in beef cattle: Effect of pre-ovulatory follicle size, CL volume, and serum concentrations of progesterone

USDA-ARS?s Scientific Manuscript database

Previous research indicates cows ovulating a small dominant follicle (<_ 12 mm) had lower pregnancy rates than cows ovulating a large follicle (> 12 mm). We hypothesized cows ovulating a small follicle would have delayed embryo development and decreased embryo quality. Objectives of this study wer...

Effect of vitrification solutions on survival rate of cryopreserved Epinephelus moara embryos.

PubMed

Tian, Y S; Zhang, J J; Li, Z T; Tang, J; Cheng, M L; Wu, Y P; Ma, W H; Pang, Z F; Li, W S; Zhai, J M; Li, B

2018-06-01

Embryo cryopreservation is important for long-term preservation of germplasm and assisted reproduction. However, it is still very difficult to obtain viable embryos from cryopreserved fish embryos. In this study, embryos of Epinephelus moara were used to investigate the effects of various cryopreservation methods. Embryos in stages 10 pairs somite (10S), 18 pairs somite (18S), 22 pairs somite (22S), tail-bud (TB), embryo twitching (ET) and pre-hatch (PH) were treated with five-step equilibrium penetration in 40% PMG3T vitrification solution, which contained 15.75% 1,2-propylene glycol, 10.50% Methanol, 8.75% Glycerol and 5.00% Trehalose. We found that 18S, 22S, TB and ET stage embryos had higher survival rates and were more tolerant to the vitrification solution. Five-step equilibrium treatments on the embryos at the tail-bud stage were performed using two vitrification solutions: 40% PMG3T and 40% PMG3S, which consisted of 15.75% 1,2-propylene glycol, 10.50% Methanol, 8.75% Glycerol and 5.00% Sucrose. The embryonic survival rate under PMG3S treatment (63.36%) was significantly higher than PMG3T treatment (43.93%) (P < 0.05). PMG3S and PMG3T with concentrations of 35%, 40% and 45% were tested on tail-bud stage embryos. Higher concentration of the vitrification solution led to significantly lower embryonic survival rate (P < 0.05). The survival rate was 36.79-72.05% in PMG3S, and 37.11-55.18% in PMG3T, and there were non-significant differences in embryonic development and malformation rates among the groups treated with different concentrations. The embryonic normal development rates in PMG3S and PMG3T were 21.27% and 11.04%, and the malformation rates were 36.13% and 31.04%, respectively. The optimum treatment condition was 40 min using 40% PMG3S on embryos at the tail-bud stage. Both PMG3S and PMG3T were used for cryopreserving embryos at 16 pairs somite, tail-bud and ET stage in liquid nitrogen, where we obtained 190 surviving embryos, and 44 fishes underwent normal development and hatched. The survival rate of cryopreserved embryos was 5.15%, the normal development rate was 1.31%, and the malformation rate was 3.66%. We found that PMG3S and PMG3T were effective for cryopreservation of Epinephelus moara embryos. The results provide a foundation for further explorations of fish embryo cryopreservation techniques. Copyright © 2018 Elsevier Inc. All rights reserved.

MiRNA-mediated regulation of cell signaling and homeostasis in the early mouse embryo.

PubMed

Pernaute, Barbara; Spruce, Thomas; Rodriguez, Tristan A; Manzanares, Miguel

2011-02-15

At the time of implantation the mouse embryo is composed of three tissues the epiblast, trophectoderm and primitive endoderm. As development progresses the epiblast goes on to form the foetus whilst the trophectoderm and primitive endoderm give rise to extra-embryonic structures with important roles in embryo patterning and nutrition. Dramatic changes in gene expression occur during early embryo development and these require regulation at different levels. miRNAs are small non coding RNAs that have emerged over the last decade as important post-transcriptional repressors of gene expression. The roles played by miRNAs during early mammalian development are only starting to be elucidated. In order to gain insight into the function of miRNAs in the different lineages of the early mouse embryo we have analysed in depth the phenotype of embryos and extra-embryonic stem cells mutant for the miRNA maturation protein Dicer. This study revealed that miRNAs are involved in regulating cell signaling and homeostasis in the early embryo. Specifically, we identified a role for miRNAs in regulating the Erk signaling pathway in the extra-embryonic endoderm, cell cycle progression in extra-embryonic tissues and apoptosis in the epiblast.

Time-lapse evaluation of human embryo development in single versus sequential culture media--a sibling oocyte study.

PubMed

Ciray, Haydar Nadir; Aksoy, Turan; Goktas, Cihan; Ozturk, Bilgen; Bahceci, Mustafa

2012-09-01

To compare the dynamics of early development between embryos cultured in single and sequential media. Randomized, comparative study. Private IVF centre. A total of 446 metaphase II oocytes from 51 couples who underwent oocyte retrieval procedure for intracytoplasmic sperm injection. Forty-nine resulted in embryo transfer. Oocytes were split between single and sequential media produced by the same manufacturer and cultured in a time-lapse incubator. Morphokinetic parameters until the embryos reached the 5-cell stage (t5), utilization, clinical pregnancy and implantation rates. Embryos cultured in single media were advanced from the first mitosis cycle and reached 2- to 5-cell stages earlier. There was not any difference between the durations for cell cycle two (cc2 = t3-t2) and s2 (t4-t3). The utilization, clinical pregnancy and implantation rates did not differ between groups. The proportion of cryopreserved day 6 embryos to two pronuclei oocytes was significantly higher in sequential than in single media. Morphokinetics of embryo development vary between single and sequential culture media at least until the 5-cell stage. The overall clinical and embryological parameters remain similar regardless of the culture system.

In vitro culture of coconut (Cocos nucifera L.) zygotic embryos.

PubMed

Engelmann, Florent; Malaurie, Bernard; N'Nan, Oulo

2011-01-01

Coconut is a very important crop for millions of people in tropical countries. With coconut, in vitro culture protocols have been developed with two main objectives, viz. the large scale production of particular types of coconuts and the international exchange and conservation of coconut germplasm. The methods described in this chapter have been developed in the framework of collaborative activities between research institutes in Côte d'Ivoire and France. Two coconut embryo in vitro collecting protocols have been established, one consisting of storing the disinfected embryos in a KCl solution until they are brought back to the laboratory, where they are re-disinfected and inoculated in vitro under sterile conditions, and the other including in vitro inoculation of the embryos in the field. For international germplasm exchange, zygotic embryos inoculated in vitro in plastic test tubes or endosperm cylinders containing embryos in plastic bags are used. For in vitro culture, embryos are inoculated on semi-solid medium supplemented with sucrose and activated charcoal and placed in the dark, and then transferred to light conditions with the same (solid or liquid) medium once the first true leaf is visible and the root system has started developing.

Shared and Unique Patterns of Embryo Development in Extremophile Poeciliids

PubMed Central

Riesch, Rüdiger; Schlupp, Ingo; Langerhans, R. Brian; Plath, Martin

2011-01-01

Background Closely related lineages of livebearing fishes have independently adapted to two extreme environmental factors: toxic hydrogen sulphide (H2S) and perpetual darkness. Previous work has demonstrated in adult specimens that fish from these extreme habitats convergently evolved drastically increased head and offspring size, while cave fish are further characterized by reduced pigmentation and eye size. Here, we traced the development of these (and other) divergent traits in embryos of Poecilia mexicana from benign surface habitats (“surface mollies”) and a sulphidic cave (“cave mollies”), as well as in embryos of the sister taxon, Poecilia sulphuraria from a sulphidic surface spring (“sulphur mollies”). We asked at which points during development changes in the timing of the involved processes (i.e., heterochrony) would be detectible. Methods and Results Data were extracted from digital photographs taken of representative embryos for each stage of development and each type of molly. Embryo mass decreased in convergent fashion, but we found patterns of embryonic fat content and ovum/embryo diameter to be divergent among all three types of mollies. The intensity of yellow colouration of the yolk (a proxy for carotenoid content) was significantly lower in cave mollies throughout development. Moreover, while relative head size decreased through development in surface mollies, it increased in both types of extremophile mollies, and eye growth was arrested in mid-stage embryos of cave mollies but not in surface or sulphur mollies. Conclusion Our results clearly demonstrate that even among sister taxa convergence in phenotypic traits is not always achieved by the same processes during embryo development. Furthermore, teleost development is crucially dependent on sufficient carotenoid stores in the yolk, and so we discuss how the apparent ability of cave mollies to overcome this carotenoid-dependency may represent another potential mechanism explaining the lack of gene flow between surface and cave mollies. PMID:22087302

Osmotic measurements in whole megagametophytes and embryos of loblolly pine (Pinus taeda) during seed development.

PubMed

Pullman, Gerald S; Johnson, Shannon

2009-06-01

Water potential (Psi) and osmotic potential (Psis) were measured weekly through the sequence of seed development in megagametophytes of loblolly pine (Pinus taeda L.). A Wescor 5500XRS vapor pressure osmometer, modified with a cycle hold switch, was used to measure Psi for whole megagametophytes containing embryos. The Psi measurements for megagametophytes with embryos removed were also attempted but readings were distorted due to cell lysates from the cut surfaces. Six seasonal sets of megagametophyte Psi profiles were generated. Megagametophytes from most of the trees examined showed a consistent Psi pattern: low measurements of -1.0 to -0.75 MPa during early embryo development in late June to early July when embryo Stages 1-2 occur; an increase for one to several weeks to levels of -0.5 to -0.75 MPa, beginning at Stages 3-5 when apical dome formation occurs; followed by a steady drop from -0.85 to -1.7 to -2.0 MPa from Stage 6 onward from late August until just before cone seed release. The Psis was measured for supernatant from centrifuged frozen-thawed megagametophyte tissue (embryos removed). Megagametophyte Psis profiles were similar for seeds analyzed from two trees and resembled Psi observations starting low, rising around Stages 4-7 and then undergoing a major reduction indicating a strong solute accumulation beginning at Stages 7-9.1. Somatic embryos stop growth prematurely in vitro at Stages 8-9.1. The major change in the accumulation of megagametophyte solutes at Stages 8-9.1 correlates with the halt in somatic embryo maturation and suggests that identifying, quantifying and using the major natural soluble compounds that accumulate during mid- to late-stage seed development may be important to improve conifer somatic embryo maturation.

Low cost labeling with highlighter ink efficiently visualizes developing blood vessels in avian and mouse embryos.

PubMed

Takase, Yuta; Tadokoro, Ryosuke; Takahashi, Yoshiko

2013-12-01

To understand how blood vessels form to establish the intricate network during vertebrate development, it is helpful if one can visualize the vasculature in embryos. We here describe a novel labeling method using highlighter ink, easily obtained in stationery stores with a low cost, to visualize embryo-wide vasculatures in avian and mice. We tested 50 different highlighters for fluorescent microscopy with filter sets equipped in a standard fluorescent microscope. The yellow and violet inks yielded fluorescent signals specifically detected by the filters used for green fluorescent protein (GFP) and red fluorescent protein (RFP) detections, respectively. When the ink solution was infused into chicken/quail and mouse embryos, vasculatures including large vessels and capillaries were labeled both in living and fixed embryos. Ink-infused embryos were further subjected to histological sections, and double stained with antibodies including QH-1 (quail), α smooth muscle actin (αSMA), and PECAM-1 (mouse), revealing that the endothelial cells were specifically labeled by the infused highlighter ink. Highlighter-labeled signals were detected with a resolution comparable to or higher than signals of fluorescein isothiocyanate (FITC)-lectin and Rhodamine-dextran, conventionally used for angiography. Furthermore, macroconfocal microscopic analyses with ink-infused embryos visualized fine vascular structures of both embryo proper and extra-embryonic plexus in a Z-stack image of 2400 μm thick with a markedly high resolution. Together, the low cost highlighter ink serves as an alternative reagent useful for visualization of blood vessels in developing avian and mouse embryos and possibly in other animals. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

Expression of mRNA encoding leukaemia inhibitory factor (LIF) and its receptor (LIFRβ) in buffalo preimplantation embryos produced in vitro: markers of successful embryo implantation.

PubMed

Eswari, S; Sai Kumar, G; Sharma, G Taru

2013-05-01

Summary The objective of this study was to evaluate the effect of supplementation of recombinant leukaemia inhibitory factor (LIF) in culture media on blastocyst development, total cell number and blastocyst hatching rates and the reverse transcription-polymerase chain reaction analysis of preimplantation buffalo embryos to determine whether they contain the LIF-encoding mRNA and its beta receptor (LIFRβ) genes in different stages of preimplantation buffalo embryos. Cumulus-oocyte complexes retrieved from slaughterhouse buffalo ovaries were matured in vitro and fertilized using frozen buffalo semen. After 18 h of co-incubation with sperm, the presumptive zygotes were cultured in modified synthetic oviductal fluid without (control) or with rhLIF (100 ng/ml). There was no significant difference in the overall cleavage rate up to morula stage however the development of blastocysts, hatching rate and total cell numbers were significantly higher in the LIF-treated group than control. Transcripts for LIFRβ were detected from immature, in vitro-matured oocytes and in the embryos up to blastocyst stage, while transcripts for the LIF were detected from 8-16-cell stage up to blastocyst, which indicated that embryo-derived LIF can act in an autocrine manner on differentiation process and blastocyst formation. This study indicated that the addition of LIF to the embryo culture medium improved development of blastocysts, functional (hatching) and morphological (number of cells) quality of the blastocysts produced in vitro. The stage-specific expression pattern of LIF and LIFRβ mRNA transcripts in buffalo embryos indicated that LIF might play an important role in the preimplantation development and subsequent implantation of buffalo embryos.

Change in desiccation tolerance of maize embryos during development and germination at different water potential PEG-6000 in relation to oxidative process.

PubMed

Huang, Hui; Song, Songquan

2013-07-01

Desiccation tolerance is one of the most important traits determining seed survival during storage and under stress conditions. However, the mechanism of seed desiccation tolerance is still unclear in detail. In the present study, we used a combined model system, desiccation-tolerant and -sensitive maize embryos with identical genetic background, to investigate the changes in desiccation tolerance, malonyldialdehyde (MDA) level, hydrogen peroxide (H₂O₂) content and antioxidant enzyme activity during seed development and germination in 0, -0.6 and -1.2 MPa polyethylene glycol (PEG)-6000 solutions. Our results indicated that maize embryos gradually acquired and lost desiccation tolerance during development and germination, respectively. The acquirement and loss of desiccation tolerance of embryos during development and germination were related to the ability of antioxidant enzymes including superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11), catalase (CAT, EC 1.11.1.6), glutathione reductase (GR, EC 1.6.4.2) and dehydroascorbate reductase (DHAR, EC 1.8.5.1) to scavenge reactive oxygen species (ROS) and to control MDA content. Compared with treatment in water, PEG-6000 treatment could markedly delay the loss of desiccation tolerance of germinating embryos by delaying water uptake and time course of germination, increasing GR activity and decreasing MDA content. Our data showed the combination of antioxidant enzyme activity and MDA content is a good parameter for assessing the desiccation tolerance of maize embryos. In addition, H₂O₂ accumulated in mature embryos and PEG-treated embryos after drying, which was at least partially related to a longer embryo/seedling length in rehydration and the physiological mechanisms of priming. Copyright © 2013. Published by Elsevier Masson SAS.

Automated image-based phenotypic analysis in zebrafish embryos

PubMed Central

Vogt, Andreas; Cholewinski, Andrzej; Shen, Xiaoqiang; Nelson, Scott; Lazo, John S.; Tsang, Michael; Hukriede, Neil A.

2009-01-01

Presently, the zebrafish is the only vertebrate model compatible with contemporary paradigms of drug discovery. Zebrafish embryos are amenable to automation necessary for high-throughput chemical screens, and optical transparency makes them potentially suited for image-based screening. However, the lack of tools for automated analysis of complex images presents an obstacle to utilizing the zebrafish as a high-throughput screening model. We have developed an automated system for imaging and analyzing zebrafish embryos in multi-well plates regardless of embryo orientation and without user intervention. Images of fluorescent embryos were acquired on a high-content reader and analyzed using an artificial intelligence-based image analysis method termed Cognition Network Technology (CNT). CNT reliably detected transgenic fluorescent embryos (Tg(fli1:EGFP)y1) arrayed in 96-well plates and quantified intersegmental blood vessel development in embryos treated with small molecule inhibitors of anigiogenesis. The results demonstrate it is feasible to adapt image-based high-content screening methodology to measure complex whole organism phenotypes. PMID:19235725

PCI-24781 can improve in vitro and in vivo developmental capacity of pig somatic cell nuclear transfer embryos.

PubMed

Jin, Long; Zhu, Hai-Ying; Guo, Qing; Li, Xiao-Chen; Zhang, Yu-Chen; Zhang, Guang-Lei; Xing, Xiao-Xu; Xuan, Mei-Fu; Luo, Qi-Rong; Yin, Xi-Jun; Kang, Jin-Dan

2016-09-01

To examine the effect of PCI-24781 (abexinostat) on the blastocyst formation rate in pig somatic cell nuclear transferred (SCNT) embryos and acetylation levels of the histone H3 lysine 9 and histone H4 lysine 12. Treatment with 0.5 nM PCI-24781 for 6 h significantly improved the development of cloned embryos, in comparison to the control group (25.3 vs. 10.5 %, P < 0.05). Furthermore, PCI-24781 treatment led to elevated acetylation of H3K9 and H4K12. TUNEL assay and Hoechst 33342 staining revealed that the percentage of apoptotic cells in blastocysts was significantly lower in PCI-24781-treated SCNT embryos than in untreated embryos. Also, PCI-24781-treated embryos were transferred into three surrogate sows, one of whom became pregnant and two fetuses developed. PCI-24781 improves nuclear reprogramming and the developmental potential of pig SCNT embryos.

Toxicity of silver nanoparticles in zebrafish models

NASA Astrophysics Data System (ADS)

Asharani, P. V.; Lian Wu, Yi; Gong, Zhiyuan; Valiyaveettil, Suresh

2008-06-01

This study was initiated to enhance our insight on the health and environmental impact of silver nanoparticles (Ag-np). Using starch and bovine serum albumin (BSA) as capping agents, silver nanoparticles were synthesized to study their deleterious effects and distribution pattern in zebrafish embryos (Danio rerio). Toxicological endpoints like mortality, hatching, pericardial edema and heart rate were recorded. A concentration-dependent increase in mortality and hatching delay was observed in Ag-np treated embryos. Additionally, nanoparticle treatments resulted in concentration-dependent toxicity, typified by phenotypes that had abnormal body axes, twisted notochord, slow blood flow, pericardial edema and cardiac arrhythmia. Ag+ ions and stabilizing agents showed no significant defects in developing embryos. Transmission electron microscopy (TEM) of the embryos demonstrated that nanoparticles were distributed in the brain, heart, yolk and blood of embryos as evident from the electron-dispersive x-ray analysis (EDS). Furthermore, the acridine orange staining showed an increased apoptosis in Ag-np treated embryos. These results suggest that silver nanoparticles induce a dose-dependent toxicity in embryos, which hinders normal development.

Physiology and culture of the human blastocyst.

PubMed

Gardner, David K; Lane, Michelle; Schoolcraft, William B

2002-01-01

The human embryo undergoes many changes in physiology during the first 4 days of life as it develops and differentiates from a fertilized oocyte to the blastocyst stage. Concomitantly, the embryo is exposed to gradients of nutrients within the female reproductive tract and exhibits changes in its own nutrient requirements and utilization. Determining the nature of such nutrient gradients in the female tract and the changing requirements of the embryo has facilitated the formulation of stage-specific culture media designed to support embryo development throughout the preimplantation period. Resultant implantation rates attained with the culture and transfer of human blastocysts are higher than those associated with the transfer of cleavage stage embryos to the uterus. Such increases in implantation rates have facilitated the establishment of high pregnancy rates while reducing the number of embryos transferred. With the introduction of new scoring systems for the blastocyst and the non-invasive assessment of metabolic activity of individual embryos, it should be possible to move to single blastocyst transfer for the majority of patients.

Miniaturized Embryo Array for Automated Trapping, Immobilization and Microperfusion of Zebrafish Embryos

PubMed Central

Akagi, Jin; Khoshmanesh, Khashayar; Evans, Barbara; Hall, Chris J.; Crosier, Kathryn E.; Cooper, Jonathan M.; Crosier, Philip S.; Wlodkowic, Donald

2012-01-01

Zebrafish (Danio rerio) has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET) is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP). The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale. PMID:22606275

Association between amino acid turnover and chromosome aneuploidy during human preimplantation embryo development in vitro

PubMed Central

Picton, Helen M.; Elder, Kay; Houghton, Franchesca D.; Hawkhead, Judith A.; Rutherford, Anthony J.; Hogg, Jan E.; Leese, Henry J.; Harris, Sarah E.

2010-01-01

This study investigated the relationship between human preimplantation embryo metabolism and aneuploidy rates during development in vitro. One hundred and eighty-eight fresh and cryopreserved embryos from 59 patients (33.9 ± 0.6 years) were cultured for 2–5 days. The turnover of 18 amino acids was measured in spent media by high-performance liquid chromatography. Embryos were either fixed for interphase fluorescent in situ hybridization analysis of chromosomes 13, 18, 19, 21, X or Y, or were assayed for mitochondrial activity. Amino acid turnover was different (P < 0.05) between stage-matched fresh and cryopreserved embryos due to blastomere loss following warming. The proportion of embryos with aneuploid cells increased as cell division progressed from pronucleate- (23%) to late cleavage stages (50–70%). Asparagine, glycine and valine turnover was significantly different between uniformly genetically normal and uniformly abnormal embryos on Days 2–3 of culture. By Days 3–4, the profiles of serine, leucine and lysine differed between uniformly euploid versus aneuploid embryos. Gender significantly (P < 0.05) affected the metabolism of tryptophan, leucine and asparagine by cleavage-stage embryos. Pronucleate zygotes had a significantly higher proportion of active:inactive mitochondria compared with cleavage-stage embryos. Furthermore, mitochondrial activity was correlated (P < 0.05) with altered aspartate and glutamine turnover. These results demonstrate the association between the metabolism, cytogenetic composition and health of human embryos in vitro. PMID:20571076

Effects of cryopreservation at various temperatures on the survival of kelp grouper (Epinephelus moara) embryos from fertilization with cryopreserved sperm.

PubMed

Tian, Yongsheng; Chen, Zhangfan; Tang, Jiang; Duan, Huimin; Zhai, Jieming; Li, Bo; Ma, Wenhui; Liu, Jiangchun; Hou, Yunxia; Sun, Zhengxiang

2017-04-01

Fish embryo cryopreservation is highly important for the long-term preservation of genomic and genetic information; however, few successful cases of fish embryo cryopreservation have been reported over the past 60 years. This is the first study to use Epinephelus moara embryos from fertilization with cryopreserved sperm as experimental material. Embryos that developed to the 16-22 somite stage and tail-bud stage were treated with the vitrification solution PMG3T according to a five-step equilibration method and cryopreserved at various temperatures and storage duration. Only 19.9 ± 9.2% of 16-22 somite stage embryos and 1.3 ± 1.1% of tail-bud stage embryos survived when cooled at 4 °C for 60 min. In total, 8.0 ± 3.0% of 16-22 somite stage embryos survived when cooled at -25.7 °C for 30 min, 22.4 ± 4.7% of tail-bud stage embryos survived after 45 min of cooling at -25.7 °C, and none survived after 60 min. Only 2.0 ± 2.7% of embryos survived when cryopreserved at -140 °C for 20 min. However, 9.7% of tail-bud stage embryos survived after cryopreservation in liquid nitrogen (-196 °C) for 2 h. Most surviving embryos developed normally. Embryonic volume decreased and spherical segments appeared when embryos were treated with higher concentrations of vitrification solution. Additionally, the volume recovered gradually after rinsing with sucrose and seawater. This is the first estimate of the survival of E. moara embryos and larvae after cryopreservation. These findings provide a foundation for further explorations of fish embryo cryopreservation techniques. Copyright © 2017 Elsevier Inc. All rights reserved.

Blastomere nucleation: Predictive factors and influence of blastomere with no apparent nuclei on blastocyst development and implantation.

PubMed

Setti, Amanda Souza; Figueira, Rita Cássia Sávio; Braga, Daniela Paes de Almeida Ferreira; Iaconelli, Assumpto; Borges, Edson

2018-06-01

To investigate whether embryos presenting blastomere(s) with no apparent nucleus (BNAN) on days 2 and 3 are more likely to fail to develop into blastocysts, hatch and implant. A total of 5705 zygotes obtained from 743 intracytoplasmic sperm injection (ICSI) cycles were analyzed. The presence and incidence of BNAN on days 2 and 3 of embryo development were recorded and then associated with ICSI outcomes. The occurrence of BNAN on day 2 of embryo development was determinant to the decreased odds of blastocyst formation (OR: 0.57, CI: 0.50-0.65), quality (OR: 0.56, CI: 0.43-0.73) and hatching status (OR: 0.66, CI: 0.50-0.87). The presence of BNAN on day 3 of embryo development was determinant to the decreased odds of blastocyst formation (OR: 0.67, CI: 0.58-0.78) and hatching status (OR: 0.61, CI: 0.45-0.83). The occurrence of BNAN on day 2 of embryo development was determinant to the decreased odds of blastocyst implantation (OR: 0.50, CI: 0.27-0.94). The presence of BNAN on day 2 or day 3 reduces development to blastocyst stage, hatching and implantation. Careful nuclear observation, taking into account the absence of blastomere nucleus, should be part of the strategies used for embryo selection.

Impact of the Z potential technique on reducing the sperm DNA fragmentation index, fertilization rate and embryo development.

PubMed

Duarte, Carlos; Núñez, Víctor; Wong, Yat; Vivar, Carlos; Benites, Elder; Rodriguez, Urso; Vergara, Carlos; Ponce, Jorge

2017-12-01

In assisted reproduction procedures, we need to develop and enhance new protocols to optimize sperm selection. The aim of this study is to evaluate the ability of the Z potential technique to select sperm with intact DNA in non-normospermic patients and evaluate the impact of this selection on embryonic development. We analyzed a total of 174 human seminal samples with at least one altered parameter. We measured basal, post density gradients, and post density gradients + Z potential DNA fragmentation index. To evaluate the impact of this technique on embryo development, 54 cases were selected. The embryo development parameters evaluated were fertilization rate, cleavage rate, top quality embryos at the third day and blastocysts rate. We found significant differences in the study groups when we compared the sperm fragmentation index by adding the Z potential technique to density gradient selection vs. density gradients alone. Furthermore, there was no significant difference in the embryo development parameters between the low sperm fragmentation index group vs. the moderate and high sperm fragmentation index groups, when selecting sperms with this new technique. The Z potential technique is a very useful tool for sperm selection; it significantly reduces the DNA fragmentation index and improves the parameters of embryo development. This technique could be considered routine for its simplicity and low cost.

Inheritance and Establishment of Gut Microbiota in Chickens

PubMed Central

Ding, Jinmei; Dai, Ronghua; Yang, Lingyu; He, Chuan; Xu, Ke; Liu, Shuyun; Zhao, Wenjing; Xiao, Lu; Luo, Lingxiao; Zhang, Yan; Meng, He

2017-01-01

In mammals, the microbiota can be transmitted from the placenta, uterus, and vagina of the mother to the infant. Unlike mammals, development of the avian embryo is a process isolated from the mother and thus in the avian embryo the gut microbial developmental process remains elusive. To explore the establishment and inheritance of the gut microbiome in the avian embryo, we used the chicken as the model organism to investigate the gut microbial composition in embryos, chicks, and maternal hens. We observed: (1) 28 phyla and 162 genera of microbes in embryos where the dominated genus was Halomonas (79%). (2) 65 genera were core microbiota in all stages with 42% and 62% gut microbial genera of embryo were found in maternal hen and chick, respectively. There was a moderate correlation (0.40) between the embryo and maternal, and 0.52 between the embryo and chick at the family level. (3) Gut microbes that are involved in substance metabolism, infectious disease, and environmental adaptation are enriched in embryos, chicks, and maternal hens, respectively. (4) 94% genera of gut microbial composition were similar among three different chicken breeds which were maintained under similar conditions. Our findings provide evidence to support the hypothesis that part of the microbial colonizers harbored in early embryos were inherited from maternal hens, and the gut microbial abundance and diversity were influenced by environmental factors and host genetic variation during development. PMID:29067020

Development and spindle formation in rat somatic cell nuclear transfer (SCNT) embryos in vitro using porcine recipient oocytes.

PubMed

Sugawara, Atsushi; Sugimura, Satoshi; Hoshino, Yumi; Sato, Eimei

2009-08-01

Cloning that uses somatic cell nuclear transfer (SCNT) technology with gene targeting could be a potential alternative approach to obtain valuable rat models. In the present study, we determined the developmental competence of rat SCNT embryos constructed using murine and porcine oocytes at metaphase II (MII). Further, we assessed the effects of certain factors, such as: (i) the donor cell type (fetal fibroblasts or cumulus cells); and (ii) premature chromosome condensation (PCC) with normal spindle formation, on the developmental competence of rat interspecies SCNT (iSCNT) embryos. iSCNT embryos that had been constructed using porcine oocytes developed to the blastocyst stage, while those embryos made using murine MII oocytes did not. Rat iSCNT embryos constructed with green fluorescent protein (GFP)-expressing fetal fibroblasts injected into porcine oocytes showed considerable PCC with a normal bipolar spindle formation. The total cell number of iSCNT blastocyst derived from GFP-expressing fetal fibroblasts was higher than the number derived from cumulus cells. In addition, these embryos expressed GFP at the blastocyst stage. This paper is the first report to show that rat SCNT embryos constructed using porcine MII oocytes have the potential to develop to the blastocyst stage in vitro. Thus the iSCNT technique, when performed using porcine MII oocytes, could provide a new bioassay system for the evaluatation of the developmental competence of rat somatic cells.

Laser Fusion of Mouse Embryonic Cells and Intra-Embryonic Fusion of Blastomeres without Affecting the Embryo Integrity

PubMed Central

Krivokharchenko, Alexander; Karmenyan, Artashes; Sarkisov, Oleg; Bader, Michael; Chiou, Arthur; Shakhbazyan, Avetik

2012-01-01

Manipulation with early mammalian embryos is the one of the most important approach to study preimplantation development. Artificial cell fusion is a research tool for various biotechnological experiments. However, the existing methods have various disadvantages, first of them impossibility to fuse selected cells within multicellular structures like mammalian preimplantation embryos. In our experiments we have successfully used high repetition rate picosecond near infrared laser beam for fusion of pairs of oocytes and oocytes with blastomeres. Fused cells looked morphologically normal and keep their ability for further divisions in vitro. We also fused two or three blastomeres inside four-cell mouse embryos. The presence of one, two or three nuclei in different blastomeres of the same early preimplantation mouse embryo was confirmed under UV-light after staining of DNA with the vital dye Hoechst-33342. The most of established embryos demonstrated high viability and developed in vitro to the blastocyst stage. We demonstrated for the first time the use of laser beam for the fusion of various embryonic cells of different size and of two or three blastomeres inside of four-cell mouse embryos without affecting the embryo’s integrity and viability. These embryos with blastomeres of various ploidy maybe unique model for numerous purposes. Thus, we propose laser optical manipulation as a new tool for investigation of fundamental mechanisms of mammalian development. PMID:23227157

Live-cell imaging of nuclear-chromosomal dynamics in bovine in vitro fertilised embryos.

PubMed

Yao, Tatsuma; Suzuki, Rie; Furuta, Natsuki; Suzuki, Yuka; Kabe, Kyoko; Tokoro, Mikiko; Sugawara, Atsushi; Yajima, Akira; Nagasawa, Tomohiro; Matoba, Satoko; Yamagata, Kazuo; Sugimura, Satoshi

2018-05-10

Nuclear/chromosomal integrity is an important prerequisite for the assessment of embryo quality in artificial reproductive technology. However, lipid-rich dark cytoplasm in bovine embryos prevents its observation by visible light microscopy. We performed live-cell imaging using confocal laser microscopy that allowed long-term imaging of nuclear/chromosomal dynamics in bovine in vitro fertilised (IVF) embryos. We analysed the relationship between nuclear/chromosomal aberrations and in vitro embryonic development and morphological blastocyst quality. Three-dimensional live-cell imaging of 369 embryos injected with mRNA encoding histone H2B-mCherry and enhanced green fluorescent protein (EGFP)-α-tubulin was performed from single-cell to blastocyst stage for eight days; 17.9% reached the blastocyst stage. Abnormalities in the number of pronuclei (PN), chromosomal segregation, cytokinesis, and blastomere number at first cleavage were observed at frequencies of 48.0%, 30.6%, 8.1%, and 22.2%, respectively, and 13.0%, 6.2%, 3.3%, and 13.4%, respectively, for abnormal embryos developed into blastocysts. A multivariate analysis showed that abnormal chromosome segregation (ACS) and multiple PN correlated with delayed timing and abnormal blastomere number at first cleavage, respectively. In morphologically transferrable blastocysts, 30-40% of embryos underwent ACS and had abnormal PN. Live-cell imaging may be useful for analysing the association between nuclear/chromosomal dynamics and embryonic development in bovine embryos.

Integration of microfluidics in animal in vitro embryo production.

PubMed

Wheeler, M B; Rubessa, M

2017-04-01

The in vitro production of livestock embryos is central to several areas of animal biotechnology. Further, the use of in vitro embryo manipulation is expanding as new applications emerge. ARTs find direct applications in increasing genetic quality of livestock, producing transgenic animals, cloning, artificial insemination, reducing disease transmission, preserving endangered germplasm, producing chimeric animals for disease research, and treating infertility. Whereas new techniques such as nuclear transfer and intracytoplasmic sperm injection are now commonly used, basic embryo culture procedures remain the limiting step to the development of these techniques. Research over the past 2 decades focusing on improving the culture medium has greatly improved in vitro development of embryos. However, cleavage rates and viability of these embryos is reduced compared with in vivo indicating that present in vitro systems are still not optimal. Furthermore, the methods of handling mammalian oocytes and embryos have changed little in recent decades. While pipetting techniques have served embryology well in the past, advanced handling and manipulation technologies will be required to efficiently implement and commercialize the basic biological advances made in recent years. Microfluidic systems can be used to handle gametes, mature oocytes, culture embryos, and perform other basic procedures in a microenvironment that more closely mimic in vivo conditions. The use of microfluidic technologies to fabricate microscale devices has being investigated to overcome this obstacle. In this review, we summarize the development and testing of microfabricated fluidic systems with feature sizes similar to the diameter of an embryo for in vitro production of pre-implantation mammalian embryos. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of temperature and oxygen on growth and differentiation of embryos of the ground skink, Scincella lateralis.

PubMed

Flewelling, Sarena; Parker, Scott L

2015-08-01

Development of reptile embryos is dependent upon adequate oxygen availability to meet embryonic metabolic demand. Metabolic rate of embryos is temperature dependent, with oxygen consumption increasing exponentially as a function of temperature. Because metabolic rate is more temperature sensitive than diffusion, developmental processes are predicted to be oxygen-limited at high temperatures. We tested the hypothesis that the amount of development lizard embryos achieve in the oviduct is dependent upon both temperature and oxygen availability. We evaluated the effect of temperature (23, 33°C) and oxygen concentration (9%, 15%, 21% O2 ) on survival and development of embryos of the oviparous skink Scincella lateralis. We predicted that incubation at 33°C under hypoxic conditions would result in higher embryo mortality due to mismatch between embryo oxygen demand and oxygen supply compared to eggs incubated at 23°C under hypoxic conditions. Embryo mortality was highest at 33°C/9% O2 (86%) compared to 23°C/9% O2 (14%), however, mortality did not differ among any other oxygen-temperature treatment combination. Both temperature and oxygen affected differentiation, but the interaction between temperature and oxygen was not significant. Embryo growth in mass and hatchling mass were affected by oxygen concentration independent of temperature treatment. Differing responses of growth and differentiation to temperature and oxygen treatments suggests that somatic growth may be more sensitive to oxygen availability than differentiation. Results indicate that embryo mortality can occur both via the direct effect of high temperature on cellular function as well as indirectly through thermally induced oxygen diffusion limitation. © 2015 Wiley Periodicals, Inc.

Fish embryos on land: terrestrial embryo deposition lowers oxygen uptake without altering growth or survival in the amphibious fish Kryptolebias marmoratus.

PubMed

Wells, Michael W; Turko, Andy J; Wright, Patricia A

2015-10-01

Few teleost fishes incubate embryos out of water, but the oxygen-rich terrestrial environment could provide advantages for early growth and development. We tested the hypothesis that embryonic oxygen uptake is limited in aquatic environments relative to air using the self-fertilizing amphibious mangrove rivulus, Kryptolebias marmoratus, which typically inhabits hypoxic, water-filled crab burrows. We found that adult mangrove rivulus released twice as many embryos in terrestrial versus aquatic environments and that air-reared embryos had accelerated developmental rates. Surprisingly, air-reared embryos consumed 44% less oxygen and possessed larger yolk reserves, but attained the same mass, length and chorion thickness. Water-reared embryos moved their opercula ∼2.5 more times per minute compared with air-reared embryos at 7 days post-release, which probably contributed to the higher rates of oxygen uptake and yolk utilization we observed. Genetically identical air- and water-reared embryos from the same parent were raised to maturity, but the embryonic environment did not affect growth, reproduction or emersion ability in adults. Therefore, although aspects of early development were plastic, these early differences were not sustained into adulthood. Kryptolebias marmoratus embryos hatched out of water when exposed to aerial hypoxia. We conclude that exposure to a terrestrial environment reduces the energetic costs of development partly by reducing the necessity of embryonic movements to dispel stagnant boundary layers. Terrestrial incubation of young would be especially beneficial to amphibious fishes that occupy aquatic habitats of poor water quality, assuming low terrestrial predation and desiccation risks. © 2015. Published by The Company of Biologists Ltd.

Fertilization and early embryonic development in heifers and lactating cows in summer and lactating and dry cows in winter.

PubMed

Sartori, R; Sartor-Bergfelt, R; Mertens, S A; Guenther, J N; Parrish, J J; Wiltbank, M C

2002-11-01

Two experiments in two seasons evaluated fertilization rate and embryonic development in dairy cattle. Experiment 1 (summer) compared lactating Holstein cows (n = 27; 97.3 +/- 4.1 d postpartum [dppl; 40.0 +/- 1.5 kg milk/d) to nulliparous heifers (n = 28; 11 to 17 mo old). Experiment 2 (winter) compared lactating cows (n = 27; 46.4 +/- 1.6 dpp; 45.9 +/- 1.4 kg milk/d) to dry cows (n = 26). Inseminations based on estrus included combined semen from four high-fertility bulls. Embryos and oocytes recovered 5 d after ovulation were evaluated for fertilization, embryo quality (1 = excellent to 5 = degenerate), nuclei/embryo, and accessory sperm. In experiment 1, 21 embryos and 17 unfertilized oocytes (UFO) were recovered from lactating cows versus 32 embryos and no UFO from heifers (55% vs. 100% fertilization). Embryos from lactating cows had inferior quality scores (3.8 +/- 0.4 vs. 2.2 +/- 0.3), fewer nuclei/embryo (19.3 +/- 3.7 vs. 36.8 +/- 3.0) but more accessory sperm (37.3 +/- 5.8 vs. 22.4 +/- 5.5/embryo) than embryos from heifers. Sperm were attached to 80% of UFO (17.8 +/- 12.1 sperm/UFO). In experiment 2, lactating cows yielded 36 embryos and 5 UFO versus 34 embryos and 4 UFO from dry cows (87.8 vs. 89.5% fertilization). Embryo quality from lactating cows was inferior to dry cows (3.1 +/- 0.3 vs. 2.2 +/- 0.3), but embryos had similar numbers of nuclei (27.2 +/- 2.7 vs. 30.6 +/- 2.1) and accessory sperm (42.0 +/- 9.4 vs. 36.5 +/- 6.3). From 53% of the flushings from lactating cows and 28% from dry cows, only nonviable embryos were collected. Thus, embryos of lactating dairy cows were detectably inferior to embryos from nonlactating females as early as 5 d after ovulation, with a surprisingly high percentage of nonviable embryos. In addition, fertilization rate was reduced only in summer, apparently due to an effect of heat stress on the oocyte.

Oxidative stress, endocrine disruption, and malformation of Bufo gargarizans embryo exposed to sub-lethal cadmium concentrations.

PubMed

Wu, Chao; Zhang, Yuhui; Chai, Lihong; Wang, Hongyuan

2017-01-01

Thyroid hormone (TH) is critical for vertebrate postembryonic development as well as embryonic development. Chinese toad (Bufo gargarizans) embryos were exposed to different concentrations of cadmium (5, 50, 100, 200 and 500μg Cd L -1 ) for 7days. Malformations were monitored daily, and growth and development of embryos were measured at day 4 and 7, and type 2 and 3 iodothyronine deiodinase (Dio2 and Dio3), thyroid hormone receptors (TRα and TRβ) mRNA levels were also measured to assess disruption of TH synthesis. In addition, superoxide dismutase (SOD), glutathione peroxidase (GPx) and heat shock proteins (HSPs) mRNA expression were examined to evaluate the ability of scavenging ROS. Our results demonstrated a bimodal inhibitory effect of Cd on the embryo growth and development of Bufo gargarizans. Reduced mean stage, total length and weight were observed at 5, 50, 200 and 500, but not at 100μg Cd L -1 . Embryos malformation occurred in all cadmium treatments. Morphological abnormalities of embryos are characterized by axial flexures, abdominal edema, stunted growth and fin flexure. Real-time PCR results show that exposure to cadmium down-regulated TRα and Dio3 mRNA expression and up-regulated Dio2 mRNA level. SOD and GPx mRNA expression was significantly up-regulated after cadmium exposure. We concluded that cadmium could change mRNA expression of TRα, Dio2 and Dio3 leading the inhibition of growth and development of B. gargarizans embryo, which suggests that cadmium might have the endocrine-disrupting effect in embryos. Moreover, the reduced ability of scavenging ROS induced by cadmium might be responsible for the teratogenic effects of cadmium. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of various freezing containers for vitrification freezing on mouse oogenesis.

PubMed

Kim, Ji Chul; Kim, Jae Myeoung; Seo, Byoung Boo

2016-01-01

In the present study, various freezing containers were tested for mouse embryos of respective developmental stages; embryos were vitrified and then their survival rate and developmental rate were monitored. Mouse two cell, 8 cell, and blastula stage embryos underwent vitrification freezing-thawing and then their recovery rate, survival rate, development rate, and hatching rate were investigated. EM-grid, OPS, and cryo-loop were utilized for vitrification freezing-thawing of mouse embryos. It was found that recovery rate and survival rate were higher in the group of cryo-loop compared to those of EM-grid (p < 0.05). Embryonic development rate, two cell embryos to blastocyst, as well as hatching rate were higher in the control group compared to the EM-grid group and OPS group (p < 0.05), yet no difference was noted between the control group and cryo-loop group. Development rate and hatching rate of eight cell morulae and blastocysts were all lower in the treatment groups than the control group whilst hatching rate of blastocysts was higher in the control group compared to the groups of EM-grid and OPS (p < 0.05); although the cryo-loop group was shown to be slightly higher than other groups, it was not statistically significant. In the study, we investigate effects of freezing containers on vitrified embryos of respective developmental stages; it was demonstrated that higher developmental rate was shown in more progressed (or developed) embryos with more blastomeres. There was however, no difference in embryonic development rate was shown amongst containers. Taken together, further additional studies are warranted with regards to 1) manipulation techniques of embryos for various vitrification freezing containers and 2) preventive measures against contamination via liquid nitrogen.

A continuous culture system of direct somatic embryogenesis in microspore-derived embryos of Brassica juncea.

PubMed

Prabhudesai, V; Bhaskaran, S

1993-03-01

An efficient culture system has been developed for repeated cycles of somatic embryogenesis in microspore-derived embryos of Brassica juncea without a callus phase. Haploid embryos produced through anther culture showed a high propensity for direct production of somatic embryos in response to 2 mgL(-1) BA and 0.1 mgL(-1) NAA. The embryogenic cultures which comprised the elongated embryonal axis of microspore-derived embryos when explanted and grown on the medium of same composition produced a large number of secondary embryos. These somatic embryos in turn underwent axis elongation and produced more somatic embryos when explanted and cultured. This cycle of repetitive somatic embryogenesis continued with undiminished vigour passage after passage and was monitored for more than a year. Somatic embryos from any passage when isolated at cotyledonary stage and grown on auxin-free medium for 5 days and then on a medium containing NAA (0.1 mgL(-1)), developed into complete plants with a profuse root system and were easily established in the soil. The cytology of the root tips of these plants confirmed their haploid nature. The total absence of callus phase makes the system ideal for continuous cloning of androgenic lines, Agrobacterium-mediated transformation and mutation induction studies.

Femtosecond laser surgery of two-cell mouse embryos: effect on viability, development, and tetraploidization.

PubMed

Osychenko, Alina A; Zalessky, Alexandr D; Kostrov, Andrey N; Ryabova, Anastasia V; Krivokharchenko, Alexander S; Nadtochenko, Viktor A

2017-12-01

The effect of the laser pulse energy and total expose of the energy incident on the embryo blastomere fusion probability was investigated. The probability of the four different events after laser pulse was determined: the fusion of two blastomeres with the following formation of tetraploid embryo, the destruction of the first blastomere occurs, the second blastomere conservation remains intact, the destruction and the death of both cells; two blastomeres were not fused, and no morphological changes occurred. We report on viability and quality of the embryo after laser surgery as a function of the laser energy incident. To characterize embryo quality, the probability of the blastocyst stage achievement was estimated and the blastocyst cells number was calculated. Blastocoel formation is the only event of morphogenesis in the preimplantation development of mammals, so we assumed it as an indicator of the time of embryonic "clocks" and observed it among fused and control embryos. The blastocoel formation time is the same for fused and control embryos. It indicates that embryo clocks were not affected due to blastomere fusion. Thus, the analysis of the fluorescence microscopic images of nuclei in the fused embryo revealed that nuclei fusion does not occur after blastomere fusion. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Effects of interval between fusion and activation, cytochalasin B treatment, and number of transferred embryos, on cloning efficiency in goats.

PubMed

Liu, J; Li, L L; Du, S; Bai, X Y; Zhang, H D; Tang, S; Zhao, M T; Ma, B H; Quan, F S; Zhao, X E; Zhang, Y

2011-10-01

To improve the efficiency of somatic cell nuclear transfer (SCNT) in goats, we evaluated the effects of the interval between fusion and activation (1 to 5 h), cytochalasin B (CB) treatment after electrofusion, and the number of transferred embryos on the in vivo and in vitro development of cloned caprine embryos. The majority of the reconstructed embryos had condensed chromosomes and metaphase-like chromosomes at 2 and 3 h after fusion; cleavage and blastocyst rates from those two groups were higher (P < 0.05) than those of embryos activated 1, 4, or 5 h after fusion. Treatment with CB between fusion and activation improved in vitro and in vivo development of nuclear transfer (NT) goat embryos by reducing the fragmentation rate (P < 0.05). Although there were no significant differences in NT efficiency, pregnancy rate and kids born per recipient were increased by transfer of 20 or 30 embryos per recipient compared with 10 embryos. We concluded that CB treatment for 2 to 3 h between fusion and activation was an efficient method for generating cloned goats by somatic cell NT. In addition, increasing the number of embryos transferred to each recipient resulted in more live offspring from fewer recipients. Copyright © 2011 Elsevier Inc. All rights reserved.

Embryo transfer: a comparative biosecurity advantage in international movements of germplasm.

PubMed

Thibier, M

2011-04-01

This paper uses cattle as a model to provide an overview of the hazards involved in the transfer of in vivo-derived and in vitro-produced embryos. While scientific studies in recent decades have led to the identification of pathogens that may be associated with both in vivo- and in vitro-derived embryos, those studies have also been the basis of appropriate disease control measures to reduce the risks to a negligible level. These disease control measures have been identified and assessed by the International Embryo Transfer Society's (lETS) Health and Safety Advisory Committee, the expert body that advises the World Organisation for Animal Health (OIE) on matters related to the safety of embryo transfer. Through the OIE's processes for developing and adopting international standards, the disease control measures identified by the IETS have been incorporated into the Terrestrial Animal Health Code. The basic principles rely on the crucial ethical roles of the embryo collection team and embryo transfer team, under the leadership of approved veterinarians. Decades of experience, with nearly 10 million embryos transferred, have demonstrated the very significant biosecurity advantage that embryo transfer technology has when moving germplasm internationally, provided that the international standards developed by the IETS and adopted by the OIE are strictly followed.

Automating fruit fly Drosophila embryo injection for high throughput transgenic studies

NASA Astrophysics Data System (ADS)

Cornell, E.; Fisher, W. W.; Nordmeyer, R.; Yegian, D.; Dong, M.; Biggin, M. D.; Celniker, S. E.; Jin, J.

2008-01-01

To decipher and manipulate the 14 000 identified Drosophila genes, there is a need to inject a large number of embryos with transgenes. We have developed an automated instrument for high throughput injection of Drosophila embryos. It was built on an inverted microscope, equipped with a motorized xy stage, autofocus, a charge coupled device camera, and an injection needle mounted on a high speed vertical stage. A novel, micromachined embryo alignment device was developed to facilitate the arrangement of a large number of eggs. The control system included intelligent and dynamic imaging and analysis software and an embryo injection algorithm imitating a human operator. Once the injection needle and embryo slide are loaded, the software automatically images and characterizes each embryo and subsequently injects DNA into all suitable embryos. The ability to program needle flushing and monitor needle status after each injection ensures reliable delivery of biomaterials. Using this instrument, we performed a set of transformation injection experiments. The robot achieved injection speeds and transformation efficiencies comparable to those of a skilled human injector. Because it can be programed to allow injection at various locations in the embryo, such as the anterior pole or along the dorsal or ventral axes, this system is also suitable for injection of general biochemicals, including drugs and RNAi.

Fossil embryos from the Middle and Late Cambrian period of Hunan, south China.

PubMed

Dong, Xi-Ping; Donoghue, Philip C J; Cheng, Hong; Liu, Jian-Bo

2004-01-15

Comparative embryology is integral to uncovering the pattern and process of metazoan phylogeny, but it relies on the assumption that life histories of living taxa are representative of their antecedents. Fossil embryos provide a crucial test of this assumption and, potentially, insight into the evolution of development, but because discoveries so far lack phylogenetic constraint, their significance is moot. Here we describe a collection of embryos from the Middle and Late Cambrian period (500 million years ago) of Hunan, south China, that preserves stages of development from cleavage to the pre-hatching embryo of a direct-developing animal comparable to living Scalidophora (phyla Priapulida, Kinorhyncha, Loricifera). The latest-stage embryos show affinity to the Lower Cambrian embryo Markuelia, whose life-history strategy contrasts both with the primitive condition inferred for metazoan phyla and with many proposed hypotheses of affinity, all of which prescribe indirect development. Phylogenetic tests based on these embryological data suggest a stem Scalidophora affinity. These discoveries corroborate, rather than contradict, the predictions of comparative embryology, providing direct historical support for the view that the life-history strategies of living taxa are representative of their stem lineages.

Epigenetic information in gametes: Gaming from before fertilization. Comment on ;Epigenetic game theory: How to compute the epigenetic control of maternal-to-zygotic transition; by Qian Wang et al.

NASA Astrophysics Data System (ADS)

Shi, Junchao; Zhang, Xudong; Liu, Ying; Chen, Qi

2017-03-01

In their interesting article [1] Wang et al. proposed a mathematical model based on evolutionary game theory [2] to tackle the fundamental question in embryo development, that how sperm and egg interact with each other, through epigenetic processes, to form a zygote and direct successful embryo development. This work is based on the premise that epigenetic reprogramming (referring to the erasure and reconstruction of epigenetic marks, such as DNA methylation and histone modifications) after fertilization might be of paramount importance to maintain the normal development of embryos, a premise we fully agree, given the compelling experimental evidence reported [3]. Wang et al. have specifically chosen to employ the well-studied DNA methylation reprogramming process during mammalian early embryo development, as a basis to develop their mathematical model, namely epigenetic game theory (epiGame). They concluded that the DNA methylation pattern in mammalian early embryo could be formulated and quantified, and their model can be further used to quantify the interactions, such as competition and/or cooperation of expressed genes that maximize the fitness of embryos. The efforts by Wang et al. in quantitatively and systematically analyzing the beginning of life apparently hold value and represent a novel direction for future embryo development research from both theoretical and experimental biologists. On the other hand, we see their theory still at its infancy, because there are plenty more parameters to consider and there are spaces for debates, such as the cases of haploid embryo development [4]. Here, we briefly comment on the dynamic process of epigenetic reprogramming that goes beyond DNA methylation, a dynamic interplay that involves histone modifications, non-coding RNAs, transposable elements et al., as well as the potential input of the various types of 'hereditary' epigenetic information in the gametes - a game that has started before the fertilization.

Synthesis of a posterior indicator protein in normal embryos and double abdomens of Smittia sp. (Chironomidae, Diptera).

PubMed Central

Jäckle, H; Kalthoff, K

1980-01-01

In embryos of the chironomid midge Smittia, synthesis of a posterior indicator protein designated PI1 (Mr approximately 50,000; pI approximately 5.5) forecasts development of an abdomen as opposed to head and thorax. The protein is synthesized several hours before germ anlage formation. In normal embryos at early blastoderm stages, synthesis of PI1 is restricted to posterior embryonic fragments but not to pole cells. In "double-abdomen" embryos, a mirror-image duplication of the abdomen is formed by cells that would otherwise develop into head and thorax. Embryos were programmed for double-abdomen development by UV irradiation of the anterior pole, and half of them were reprogrammed for normal development by subsequent exposure to visible light (photoreversal). Correspondingly, PI1 was synthesized in anterior fragments of UV-irradiated embryos but not after photoreversal. In a control experiment, UV irradiation of the posterior pole caused neither double-abdomen formation nor PI1 synthesis in anterior fragments. The identity of PI1 formed in anterior fragments of prospective double abdomens with the protein found in posterior fragments was revealed by two-dimensional gel electrophoresis and limited proteolysis. Suppression of PI1 synthesis in anterior fragments of normal embryos is ascribed to the activity of cytoplasmic ribonucleoprotein particles thought to act as anterior determinants. Images PMID:6935679

Vitamin C enhances in vitro and in vivo development of porcine somatic cell nuclear transfer embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Yongye; Tang, Xiaochun; Xie, Wanhua

Highlights: {yields} Report for the first time that vitamin C has a beneficial effect on the development of porcine SCNT embryos. {yields} The level of acH4K5 and Oct4 expression at blastocyst-stage was up-regulated after treatment. {yields} A higher rate of gestation and increased number of piglets born were harvested in the treated group. -- Abstract: The reprogramming of differentiated cells into a totipotent embryonic state through somatic cell nuclear transfer (SCNT) is still an inefficient process. Previous studies revealed that the generation of induced pluripotent stem (iPS) cells from mouse and human fibroblasts could be significantly enhanced with vitamin Cmore » treatment. Here, we investigated the effects of vitamin C, to our knowledge for the first time, on the in vitro and in vivo development of porcine SCNT embryos. The rate of blastocyst development in SCNT embryos treated with 50 {mu}g/mL vitamin C 15 h after activation (36.0%) was significantly higher than that of untreated SCNT embryos (11.5%). The enhanced in vitro development rate of vitamin C-treated embryos was associated with an increased acetylation level of histone H4 lysine 5 and higher Oct4, Sox2 and Klf4 expression levels in blastocysts, as determined by real-time PCR. In addition, treatment with vitamin C resulted in an increased pregnancy rate in pigs. These findings suggest that treatment with vitamin C is beneficial for enhancement of the in vitro and in vivo development of porcine SCNT embryos.« less

INFECTIVITY OF METARHIZIUM ANISOPLIAE IN GRASS SHRIMP EMBRYOS

EPA Science Inventory

Developing embryos of the estuarine grass shrimp, Palaemonetes pugio, were exposed to Metarhizium anisopliae conidiospores. Attachment of conidiospores was often followed by germination and outgrowth on embryo surface. Penetration of the embryonic envelopes by M. anisopliae allow...

Selection against BALB/c strain cells in mouse chimaeras

PubMed Central

Tang, Pin-Chi; MacKay, Gillian E.; Flockhart, Jean H.; Keighren, Margaret A.; Kopakaki, Anna

2018-01-01

ABSTRACT It has been shown previously that BALB/c strain embryos tend to contribute poorly to mouse aggregation chimaeras. In the present study we showed that BALB/c cells were not preferentially allocated to any extraembryonic lineages of mouse aggregation chimaeras, but their contribution decreased during the early postimplantation period and they were significantly depleted by E8.5. The development of BALB/c strain preimplantation embryos lagged behind embryos from some other strains and the contribution that BALB/c and other embryos made to chimaeras correlated with their developmental stage at E2.5. This relationship suggests that the poor contribution of BALB/c embryos to aggregation chimaeras is at least partly a consequence of generalised selection related to slow or delayed preimplantation development. The suitability of BALB/c embryos for maximising the ES cell contribution to mouse ES cell chimaeras is also discussed. PMID:29330350

Ultrastructural analyses of somatic embryo initiation, development and polarity establishment from mesophyll cells of Dactylis glomerata

NASA Technical Reports Server (NTRS)

Vasilenko, A.; McDaniel, J. K.; Conger, B. V.

2000-01-01

Somatic embryos initiate and develop directly from single mesophyll cells in in vitro-cultured leaf segments of orchardgrass (Dactylis glomerata L.). Embryogenic cells establish themselves in the predivision stage by formation of thicker cell walls and dense cytoplasm. Electron microscopy observations for embryos ranging from the pre-cell-division stage to 20-cell proembryos confirm previous light microscopy studies showing a single cell origin. They also confirm that the first division is predominantly periclinal and that this division plane is important in establishing embryo polarity and in determining the embryo axis. If the first division is anticlinal or if divisions are in random planes after the first division, divisions may not continue to produce an embryo. This result may produce an embryogenic cell mass, callus formation, or no structure at all. Grant numbers: NAGW-3141, NAG10-0221.

Effect of PMA-induced protein kinase C activation on development and apoptosis in early zebrafish embryos.

PubMed

Hrubik, Jelena; Glisic, Branka; Samardzija, Dragana; Stanic, Bojana; Pogrmic-Majkic, Kristina; Fa, Svetlana; Andric, Nebojsa

2016-12-01

Protein kinase C (PKC) isoforms have been implicated in several key steps during early development, but the consequences of xenobiotic-induced PKC activation during early embryogenesis are still unknown. In this study, zebrafish embryos were exposed to a range of phorbol 12-myristate 13-acetate (PMA) concentrations (0-200μg/L) at different time points after fertilization. Results showed that 200μgPMA/L caused development of yolk bags, cardiac edema, slow blood flow, pulsating blood flow, slow pulse, elongated heart, lack of tail fins, curved tail, and coagulation. PMA exposure decreased survival rate of the embryos starting within the first 24h and becoming more pronounced after prolonged exposure (96h). PMA increased the number of apoptotic cells in the brain region as demonstrated by acridine orange staining and caused up-regulation of caspase 9 (casp9) and p53 up-regulated modulator of apoptosis (puma) mRNA in whole embryos. PMA caused oxidative stress in the embryos as demonstrated by decreased mRNA expression of catalase and superoxide dismutase 2. Inhibition of Pkc with GF109203X improved overall survival rate, reduced apoptosis in the brain and decreased expression of casp9 and puma in the PMA-exposed embryos. However, Pkc inhibition neither prevented development of deformities nor reversed oxidative stress in the PMA-exposed embryos. These data suggest that direct over-activation of Pkc during early embryogenesis of zebrafish is associated with apoptosis and decreased survival rate of the embryos. Copyright © 2016 Elsevier Inc. All rights reserved.

Methods for imaging individual cilia in living echinoid embryos.

PubMed

Morris, Robert L; Pope, Hans W; Sholi, Adam N; Williams, Leah M; Ettinger, Chelsea R; Beacham, Gwendolyn M; Shintaku, Tatsushi; Abbott, Zachary D; Doherty, Elyse M

2015-01-01

The embryos of echinoids (sea urchins and sand dollars) serve as excellent models for studying cilia differentiation and stages of the cilia life cycle including ciliogenic initiation, growth, maintenance, and retraction. Early in echinoid development, uniform motile cilia form on all cells simultaneously but then rapidly differentiate into multiple cilia types that differ in morphology, motility, and signaling sensitivity. Metal ion treatments that shift germ layer boundaries and thereby "animalize" or "vegetalize" embryos can be used to enrich for low-abundance cilia types rendering those specialized cilia and the differentiation processes they exhibit much easier to study. The experimental advantages of having robust cilia growth and differentiation is tempered by the challenge of restraining ciliated embryos well enough to view the process of ciliogenesis live. We have developed four observation chambers as modifications of the Kiehart chamber for long-term light microscopic imaging of ciliated echinoid embryos. One of these systems employs paramagnetic beads to render ciliated larvae magnetic so they can be gently and reversibly trapped directly under the objective lens. With this magnetic trapping system, the larva can be positioned and repositioned until they achieve the orientation with the clearest view of any cilia of interest. These methods of gentle embryo restraint allow normal embryo development and the normal ciliogenic cycle and ciliary differentiation processes to continue in direct view. Sequential image series can then be collected and analyzed to quantitatively study the wide spectrum of cilia behaviors and properties that arise in developing echinoid embryos. Copyright © 2015. Published by Elsevier Inc.

Graphic and movie illustrations of human prenatal development and their application to embryological education based on the human embryo specimens in the Kyoto collection.

PubMed

Yamada, Shigehito; Uwabe, Chigako; Nakatsu-Komatsu, Tomoko; Minekura, Yutaka; Iwakura, Masaji; Motoki, Tamaki; Nishimiya, Kazuhiko; Iiyama, Masaaki; Kakusho, Koh; Minoh, Michihiko; Mizuta, Shinobu; Matsuda, Tetsuya; Matsuda, Yoshimasa; Haishi, Tomoyuki; Kose, Katsumi; Fujii, Shingo; Shiota, Kohei

2006-02-01

Morphogenesis in the developing embryo takes place in three dimensions, and in addition, the dimension of time is another important factor in development. Therefore, the presentation of sequential morphological changes occurring in the embryo (4D visualization) is essential for understanding the complex morphogenetic events and the underlying mechanisms. Until recently, 3D visualization of embryonic structures was possible only by reconstruction from serial histological sections, which was tedious and time-consuming. During the past two decades, 3D imaging techniques have made significant advances thanks to the progress in imaging and computer technologies, computer graphics, and other related techniques. Such novel tools have enabled precise visualization of the 3D topology of embryonic structures and to demonstrate spatiotemporal 4D sequences of organogenesis. Here, we describe a project in which staged human embryos are imaged by the magnetic resonance (MR) microscope, and 3D images of embryos and their organs at each developmental stage were reconstructed based on the MR data, with the aid of computer graphics techniques. On the basis of the 3D models of staged human embryos, we constructed a data set of 3D images of human embryos and made movies to illustrate the sequential process of human morphogenesis. Furthermore, a computer-based self-learning program of human embryology is being developed for educational purposes, using the photographs, histological sections, MR images, and 3D models of staged human embryos. Copyright 2005 Wiley-Liss, Inc.

Embryonic genotype and inbreeding affect preimplantation development in cattle.

PubMed

Lazzari, G; Colleoni, S; Duchi, R; Galli, A; Houghton, F D; Galli, C

2011-05-01

Infertility in cattle herds is a growing problem with multifactorial causes. Embryonic genotype and level of inbreeding are among the many factors that can play a role on reproductive efficiency. To investigate this issue, we produced purebred and crossbred bovine embryos by in vitro techniques from Holstein oocytes and Holstein or Brown Swiss semen and analyzed several cellular and molecular features. In the first experiment, purebred and crossbred embryos, obtained from abattoir oocytes, were analyzed for cleavage, development to morula/blastocyst stages, amino acid metabolism and gene expression of developmentally important genes. The results indicated significant differences in the percentage of compacted morulae, in the expression of three genes at the blastocyst stage (MNSOD, GP130 and FGF4) and in the utilization of serine, asparagine, methionine and tryptophan in day 6 embryos. In the second experiment, bovine oocytes were collected by ovum pick up from ten Holstein donors and fertilized with the semen of the respective Holstein sires or with Brown Swiss semen. The derived embryos were grown in vitro up to day 7, and were then transferred to synchronized recipients and recovered on day 12. We found that purebred/inbred embryos had lower blastocyst rate on days 7-8, were smaller on day 12 and had lower expression of the trophoblast gene PLAC8. Overall, these results indicate reduced and delayed development of purebred embryos compared with crossbred embryos. In conclusion, this study provides evidence that embryo genotype and high inbreeding can affect amino acid metabolism, gene expression, preimplantation development and therefore fertility in cattle.

[In vitro development and chimeric efficiency of mouse-porcine interspecies chimeric embryos in different culture systems].

PubMed

Wang, Ying; Ren, Jilong; Song, Yuran; Hai, Tang; Zhou, Qi; Liu, Zhonghua

2016-07-25

With the advancements of stem cells and regenerative medicine, interspecies chimera has become a hot topic and will pave a new way of providing donor sources in organ transplantation. However, the interspecies chimera is confronted with a number of scientific questions and technical obstacles, including selections of appropriate embryonic stage and appropriate culture medium; those factors will deeply influence the developmental balance between donor cells and receptor embryos. Due to its relatively rapid reproductive cycle and similar organ size to human's, porcine is a very potential donor candidate to study these questions. To compare the development and chimeric efficiency of interspecies embryos, we tested and evaluated three different culture systems, PZM-3 (Porcine zygotic medium), culture medium for iPSCs (N2B27) and 3.5 h of N2B27 before PZM-3 (N2B27(3.5 h)), and two different embryonic stages, 8-cell and blastocyst in mouse-porcine chimeric embryos using parthenogenetically activated porcine embryos and mouse induced pluripotent stem cells (miPS). The results showed that, PZM-3 was beneficial for both development of chimeric embryos and miPSCs proliferation in porcine embryos in the 8-cell injection group. After early blastocyst injection, the chimeric efficiency did not appear significantly different among the three culture systems but was lower than 8-cell injection. In summary, the results suggest that 8-cell injection and PZM-3 culture medium are more beneficial to the in vitro development and chimeric efficiency of mouse-porcine chimeric embryos.

A medium-chain fatty acid as an alternative energy source in mouse preimplantation development.

PubMed

Yamada, Mitsutoshi; Takanashi, Kazumi; Hamatani, Toshio; Hirayama, Akiyoshi; Akutsu, Hidenori; Fukunaga, Tomoko; Ogawa, Seiji; Sugawara, Kana; Shinoda, Kosaku; Soga, Tomoyoshi; Umezawa, Akihiro; Kuji, Naoaki; Yoshimura, Yasunori; Tomita, Masaru

2012-01-01

To further optimize the culturing of preimplantation embryos, we undertook metabolomic analysis of relevant culture media using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). We detected 28 metabolites: 23 embryo-excreted metabolites including 16 amino acids and 5 media-derived metabolites (e.g., octanoate, a medium-chain fatty acid (MCFA)). Due to the lack of information on MCFAs in mammalian preimplantation development, this study examined octanoate as a potential alternative energy source for preimplantation embryo cultures. No embryos survived in culture media lacking FAs, pyruvate, and glucose, but supplementation of octanoate rescued the embryonic development. Immunoblotting showed significant expression of acyl-CoA dehydrogenase and hydroxyacyl-CoA dehydrogenase, important enzymes for ß-oxidation of MCFAs, in preimplantation embryo. Furthermore, CE-TOFMS traced [1-(13)C(8)] octanoate added to the culture media into intermediate metabolites of the TCA cycle via ß-oxidation in mitochondria. These results are the first demonstration that octanoate could provide an efficient alternative energy source throughout preimplantation development.

Oxygen decline in biotesting of environmental samples--is there a need for consideration in the acute zebrafish embryo assay?

PubMed

Küster, Eberhard; Altenburger, Rolf

2008-12-01

Environmental samples such as groundwater, sediment pore water, native or freeze dried sediments may be difficult to analyze for toxic effects with organismic aquatic bioassays. These samples might evoke low oxygen concentration or oxygen depletion during the test. The toxicity assessment could thus be confounded by low oxygen concentrations. The acute zebrafish embryo assay was used to analyze the influence of oxygen deficit on the embryonic development in the first 48 h post fertilization. Embryos were exposed to varying oxygen concentrations ranging from <30 to >80% oxygen saturation of water. A clear concentration dependent retardation of fish embryo development was observed. Because of a retarded development toxic thresholds of environmental samples which might include substances slowing down the development will be altered. For the purpose of identification of critical contaminants in complex environmental samples, it is proposed to actively aerate environmental samples which are likely to be oxygen depleted during the duration of the zebrafish embryo bioassay. 2008 Wiley Periodicals, Inc.

Towards a CRISPR view of early human development: applications, limitations and ethical concerns of genome editing in human embryos.

PubMed

Plaza Reyes, Alvaro; Lanner, Fredrik

2017-01-01

Developmental biologists have become increasingly aware that the wealth of knowledge generated through genetic studies of pre-implantation mouse development might not easily be translated to the human embryo. Comparative studies have been fueled by recent technological advances in single-cell analysis, allowing in-depth analysis of the human embryo. This field could shortly gain more momentum as novel genome editing technologies might, for the first time, also allow functional genetic studies in the human embryo. In this Spotlight article, we summarize the CRISPR-Cas9 genome editing system and discuss its potential applications and limitations in human pre-implantation embryos, and the ethical considerations thereof. © 2017. Published by The Company of Biologists Ltd.

Examination of Chesapeake Bay Observing System for Local Environmental Data for Coast Guard Operations

DTIC Science & Technology

2004-12-01

U.S. Coast Guard Research and Development Center 1082 Shennecossett Road, Groton, CT 06340-6048 Report No. CG-D-04-05 Examination of Chesapeake Bay...Director "United States Coast Guard Research & Development Center 1082 Shennecossett Road r Groton, CT 06340-6048 ii Technical Report Documentation Page...and Mary Research & Development Center 11. Contract or Grant No. Route 1208, Greate Road 1082 Shennecossett Road DTCG32-03-C-R0006 Gloucester Point, VA

Shaping the norms that regulate international commerce of embryos.

PubMed

Gard, Julie A; Stringfellow, David A

2014-01-01

As various embryo technologies in livestock were developed and evolved to a state of usefulness over the past 40 years, scientists with a specific interest in infectious diseases sought to determine the epidemiologic consequences of movement, especially international movement, of increasing numbers of embryos. Many of the foundational studies in this area were reported in Theriogenology, beginning in the 1970s and especially throughout the 1980s and 1990s. Unquestionably, Theriogenology has been a widely used venue for dissemination of basic information on this subject, which ultimately led to the development of the now universally accepted techniques for certification of embryo health. Today it is well-recognized that movement in commerce of embryos, especially in vivo-derived embryos, is a very low-risk method for exchange of animal germ plasm. This paper chronicles the evolution of strategies for health certification of embryos. An overview is provided of the calculated efforts of practitioners, scientists, and regulators to organize, forge necessary partnerships, stimulate needed research, provide purposeful analysis of the results, and, through these processes, guarantee the universal acceptance of efficient protocols for certifying the health of embryos intended for movement in international commerce. Copyright © 2014 Elsevier Inc. All rights reserved.

Glassfrog embryos hatch early after parental desertion.

PubMed

Delia, Jesse R J; Ramírez-Bautista, Aurelio; Summers, Kyle

2014-06-22

Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations.

Glassfrog embryos hatch early after parental desertion

PubMed Central

Delia, Jesse R. J.; Ramírez-Bautista, Aurelio; Summers, Kyle

2014-01-01

Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations. PMID:24789892

Birth of rats following nuclear exchange at the 2-cell stage.

PubMed

Roh, Sangho; Guo, Jitong; Malakooti, Nakisa; Morrison, John R; Trounson, Alan O; Du, Zhong Tao

2003-11-01

We report full-term development of nuclear transfer embryos following nuclear exchange at the 2-cell stage. Nuclei from 2-cell rat embryos were transferred into enucleated 2-cell embryos and developed to term after transfer to recipients (NT2). Pronuclear exchange in zygotes was used for comparison (NT1). Zygotes and 2-cell embryos were harvested from 4-week-old female Sprague-Dawley rats. Nuclear transfer was performed by transferring the pronuclei or karyoplasts into the perivitelline space of recipient embryos followed by electrofusion to reconstruct embryos. Fused couplets were cultured for 4 or 24 h before being transferred into day 1 pseudopregnant recipients (Hooded Wistar) at the 1- or 2-cell stage. In vitro culture was also carried out to check the developmental competence of the embryos. In vitro development to the blastocyst stage was not significantly different between the two groups (NT1, 34.3%; NT2, 45.0%). Two of three recipients from NT1 and two of five recipients from NT2 became pregnant. Six pups (3 from NT1, 3 from NT2) were delivered from the four foster mothers. Three female pups survived; 2 from NT1 and 1 from NT2. At 2 months of age these pups appeared healthy, and were mated with Sprague-Dawley males. One rat derived from NT1 delivered 15 pups (5 males, 10 females) as did the rat from NT2 (7 males, 8 females). Our results show that by using karyoplasts from 2-cell stage embryos as nuclear donors and reconstructing them with enucleated 2-cell embryos, healthy rats can be produced.

The Phosphorylated Pathway of Serine Biosynthesis Is Essential Both for Male Gametophyte and Embryo Development and for Root Growth in Arabidopsis[W

PubMed Central

Cascales-Miñana, Borja; Muñoz-Bertomeu, Jesús; Flores-Tornero, María; Anoman, Armand Djoro; Pertusa, José; Alaiz, Manuel; Osorio, Sonia; Fernie, Alisdair R.; Segura, Juan; Ros, Roc

2013-01-01

This study characterizes the phosphorylated pathway of Ser biosynthesis (PPSB) in Arabidopsis thaliana by targeting phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Lack of PSP1 activity delayed embryo development, leading to aborted embryos that could be classified as early curled cotyledons. The embryo-lethal phenotype of psp1 mutants could be complemented with PSP1 cDNA under the control of Pro35S (Pro35S:PSP1). However, this construct, which was poorly expressed in the anther tapetum, did not complement mutant fertility. Microspore development in psp1.1/psp1.1 Pro35S:PSP1 arrested at the polarized stage. The tapetum from these lines displayed delayed and irregular development. The expression of PSP1 in the tapetum at critical stages of microspore development suggests that PSP1 activity in this cell layer is essential in pollen development. In addition to embryo death and male sterility, conditional psp1 mutants displayed a short-root phenotype, which was reverted in the presence of Ser. A metabolomic study demonstrated that the PPSB plays a crucial role in plant metabolism by affecting glycolysis, the tricarboxylic acid cycle, and the biosynthesis of amino acids. We provide evidence of the crucial role of the PPSB in embryo, pollen, and root development and suggest that this pathway is an important link connecting primary metabolism with development. PMID:23771893

Incorporation of Tritium-labelled Thymidine in Bufo $female$ × Rana temporaria $male$ Hybrid Embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

TENCER, B.

1961-04-01

Two-cell stages of hybrid embryos resulting from the cross-fertilization of Bufo and Rana temporaria were incubated for 17 hrs in a medium containing tritium-labeled thymidine. The embryos were fixed by freeze-substitution and the incorporation of tritium studied by the radioautographic technique. The embryos stopped development at the late blastula stage. Labeling of desoxyribonucleic acid was demonstrated in morula as well as in blastula cells of the lethal hybrids. Tritium-labeled thymidine was shown to be incorporated into desoxyribonucleic acid 24 hr after development stopped, which suggests that the block in development was not due to the arrest of desoxyribonucleic acid synthesis.more » (C.H.)« less

The effect of immature oocytes quantity on the rates of oocytes maturity and morphology, fertilization, and embryo development in ICSI cycles.

PubMed

Halvaei, Iman; Ali Khalili, Mohammad; Razi, Mohammad Hossein; Nottola, Stefania A

2012-08-01

The goal was to evaluate the role of the number of retrieved immature oocytes on mature oocyte counts and morphology, and also the rates of fertilization and embryo development in ICSI cycles. 101 ICSI cycles were included in this prospective evaluation. Patients were divided into 2 groups of A (≤ 2 immature oocytes) and B (> 2 immature oocytes). In sub-analysis, the impacts of the number of GV and MI oocytes were assessed on the rates of fertilization and embryo development. Also, correlations between the numbers of immature and mature oocytes, as well as maternal age between two groups were analyzed. Assessments of oocyte morphology, fertilization, embryo quality and development were done accordingly. There was no correlation between the immature oocytes quantity with the number of mature ones. There were insignificant differences for embryo development between two groups, but fertilization rate was higher in group A (P = 0.03). In sub-analysis, insignificant differences were observed between two groups of ≤ and >2 GV and MI oocytes for rates of fertilization and embryo development. Also, the rates of clinical pregnancy and delivery were insignificant between groups. The rate of morphologically abnormal oocytes had no significant difference between two groups, except for wide perivitelline space (PVS) which was higher in group A (P = 0.03). There was no significant difference for maternal age between two groups. In cases with few retrieved immature oocytes, rates of fertilization and incidence of wide PVS may increase, although immature oocytes may not have any negative impacts on early embryo development, or the rates on number of mature oocytes.

Effect of steroid treatment of endometrial cells on blastocyst development during co-culture.

PubMed

Goff, A K; Smith, L C

1998-04-01

The objective of this study was to determine if treatment of endometrial cells with progesterone or progesterone plus estradiol would improve the development of bovine embryos to the blastocyst stage during co-culture. After IVF, bovine embryos were cultured with oviduct epithelial cells for 3 d. In Experiment 1 the embryos were cultured with a) oviduct epithelial cells; b) endometrial epithelial cells (EEC); c) EEC with 10 ng/ml progesterone (EEC + P); or d) EEC with 10 ng/ml progesterone and 10 pg/ml estradiol (EEC + PE) for 6 d. In Experiment 2 the embryos were cultured with a) oviduct epithelial cells; b) endometrial stromal cells (ESC); c) ESC with 10 ng/ml progesterone (ESC + P); or d) ESC with 10 ng/ml progesterone and 10 pg/ml estradiol (ESC + PE) for 6 d. Results from Experiment 1 showed that endometrial epithelial cells supported development to the blastocyst stage as effectively as the oviduct cells; however, the size of the blastocysts was smaller for the endometrial cells. There was no effect of steroid hormone treatment on development to the blastocyst stage or on the size of the blastocysts. Results from Experiment 2 showed that stromal cells supported development to the blastocyst stage as effectively as oviduct cells. The hatching rate was lower when the embryos were co-cultured with stromal cells than oviduct epithelial cells; but there was no effect of steroid treatment. These data show that untreated endometrial epithelial cells are as effective as oviduct cells in maintaining embryo development to the blastocyst stage. However, embryo development was not improved by steroid treatment of the cells.

Embryo sac formation and early embryo development in Agave tequilana (Asparagaceae).

PubMed

González-Gutiérrez, Alejandra G; Gutiérrez-Mora, Antonia; Rodríguez-Garay, Benjamín

2014-01-01

Agave tequilana is an angiosperm species that belongs to the family Asparagaceae (formerly Agavaceae). Even though there is information regarding to some aspects related to the megagametogenesis of A. tequilana, this is the first report describing the complete process of megasporogenesis, megagametogenesis, the early embryo and endosperm development process in detail. The objective of this work was to study and characterize all the above processes and the distinctive morphological changes of the micropylar and chalazal extremes after fertilization in this species. The agave plant material for the present study was collected from commercial plantations in the state of Jalisco, Mexico. Ovules and immature seeds, previously fixed in FAA and kept in ethanol 70%, were stained based on a tissue clarification technique by using a Mayer's-Hematoxylin solution. The tissue clarification technique was successfully used for the characterization of the megasporogenesis, megagametogenesis, mature embryo sac formation, the early embryo and endosperm development processes by studying intact cells. The embryo sac of A. tequilana was confirmed to be of the monosporic Polygonum-type and an helobial endosperm formation. Also, the time-lapse of the developmental processes studied was recorded.

An automated microfluidic platform for C. elegans embryo arraying, phenotyping, and long-term live imaging

NASA Astrophysics Data System (ADS)

Cornaglia, Matteo; Mouchiroud, Laurent; Marette, Alexis; Narasimhan, Shreya; Lehnert, Thomas; Jovaisaite, Virginija; Auwerx, Johan; Gijs, Martin A. M.

2015-05-01

Studies of the real-time dynamics of embryonic development require a gentle embryo handling method, the possibility of long-term live imaging during the complete embryogenesis, as well as of parallelization providing a population’s statistics, while keeping single embryo resolution. We describe an automated approach that fully accomplishes these requirements for embryos of Caenorhabditis elegans, one of the most employed model organisms in biomedical research. We developed a microfluidic platform which makes use of pure passive hydrodynamics to run on-chip worm cultures, from which we obtain synchronized embryo populations, and to immobilize these embryos in incubator microarrays for long-term high-resolution optical imaging. We successfully employ our platform to investigate morphogenesis and mitochondrial biogenesis during the full embryonic development and elucidate the role of the mitochondrial unfolded protein response (UPRmt) within C. elegans embryogenesis. Our method can be generally used for protein expression and developmental studies at the embryonic level, but can also provide clues to understand the aging process and age-related diseases in particular.

Influence of culture medium composition on relative mRNA abundances in domestic cat embryos.

PubMed

Hribal, R; Jewgenow, K; Braun, B C; Comizzoli, P

2013-04-01

Different culture conditions have been used to produce domestic cat embryos. As part of the in vitro procedures, the medium composition significantly affects the quality of the embryo development also. Quality assessments based on cleavage kinetics and blastomere symmetry are useful, but embryos also can differ in their relative gene expression patterns despite similar morphological characteristics. The aim of this study was to compare cat embryos produced with two different in vitro culture systems routinely used in two different laboratories [Smithsonian Conservation Biology Institute, Washington D.C., USA (SCBI) and Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany (IZW)]. Specifically, relative mRNA expression patterns of critical genes for pre-implantation embryo development were assessed in both conditions. Embryos were produced in parallel in both culture systems by IVF using frozen-thawed ejaculated semen in the United States and fresh epididymal sperm in Germany. Success of embryo development in vitro was recorded as well as relative mRNA abundances [DNA methyltransferases 1 and 3A (DNMT1, DNMT3A), gap junction protein alpha 1 (GJA1), octamer-binding transcription factor 4 [OCT4], insulin-like growth factors 1 and 2 receptors (IGF1R, IGF2R), beta-actin (ACTB)] in pools of days 4-5 morulae by semi-quantitative RT-PCR assay. Percentages of cleaved embryos were similar (p > 0.05) between both culture systems, regardless of the location. OCT4 mRNA abundance was higher (p < 0.05) in embryos derived in the SCBI culture system compared with those from the IZW system when epididymal sperm was used for IVF. No clear correlation between the expression pattern and the culture system could be found for all other genes. It is suggested that OCT4 expression might be affected by the media composition in some conditions and can be the indicator of a better embryo quality. © 2012 Blackwell Verlag GmbH.

Development, glycolytic activity, and viability of preimplantation mouse embryos subjected to different periods of glucose starvation.

PubMed

Leppens-Luisier, G; Sakkas, D

1997-03-01

After compaction, the preimplantation mouse embryo switches to a glucose-based metabolism, whereas for the 2- to 4-cell stage embryo, glucose can be inhibitory. In this study, we investigated the adaptability of preimplantation embryos to different periods of glucose starvation by culturing in vitro fertilized (IVF) and in vivo-fertilized 1-cell OF1 mouse embryos. Blastocysts obtained from exposure to glucose starvation for different periods of time were examined for the number of cells in the trophectoderm and inner cell mass, and for glycolytic activity and viability. A high percentage of blastocysts was obtained when 1-cell embryos fertilized in vitro or in vivo were cultured in M16 until the 2-cell stage, were transferred to M16 without glucose (M16-G) until the 4- or 8-cell stage, and then were transferred to fresh M16-G. When in vivo-fertilized 1-cell embryos were cultured to the 2-cell stage and then left in M16, less than 5% formed blastocysts compared to 26% of those transferred into M16-G. Blastocysts obtained when in vivo-fertilized 1-cell embryos were left in M16-G after the 2-cell stage, however, showed a significantly elevated glycolytic activity compared to those transferred to fresh M16 or M16-G medium at the 4- or 8-cell stage. Interestingly, even though these embryos displayed elevated glycolytic activity, they did not exhibit differences in the numbers of inner cell mass and trophectoderm cells or in viability compared to embryos cultured according to other protocols. Blastocysts from all cultured protocols had a significantly lower total cell number and a lower trophectoderm, but not inner cell mass, cell number compared to blastocysts developed in vivo. This study documents the metabolic adaptability of the preimplantation embryo by highlighting its ability to proceed with development and retain viability when challenged with glucose starvation at different periods.

Effect of embryo source and recipient progesterone environment on embryo development in cattle.

PubMed

Lonergan, P; Woods, A; Fair, T; Carter, F; Rizos, D; Ward, F; Quinn, K; Evans, A

2007-01-01

The aim of the present study was to examine the effect of embryo source (in vivo v. in vitro) and the progesterone environment into which it was transferred on Day 7 on embryo survival and size on Day 13. Day 7 blastocysts were produced either in vivo using superovulation, artificial insemination and non-surgical embryo recovery or in vitro using in vitro maturation, fertilisation and culture. In order to produce animals with divergent progesterone concentrations, following synchronisation recipients were either superovulated (High progesterone; n = 10) or not (Control progesterone; n = 10). Ten blastocysts, produced either in vivo or in vitro, were transferred to each recipient on Day 7. Both groups were killed on Day 13. The mean progesterone concentration from Day 7 to Day 13 (the period when the embryos were in the uterus) in the High and Control progesterone recipients was 36.32 +/- 1.28 and 10.30 +/- 0.51 ng mL(-1), respectively. Of the in vivo embryos transferred, the overall recovery rate at Day 13 was 64%, which was higher (P < 0.001) than that of 20% for the in vitro embryos transferred. The mean area of embryos recovered from High progesterone recipients was 3.86 +/- 0.45 mm(2) (n = 28) compared with 1.66 +/- 0.38 mm(2) (n = 24) for embryos recovered from Control progesterone recipients (P < 0.001). Similarly, the origin of the embryo used for transfer affected embryo size on Day 13. In summary, the recovery rate of blastocysts was higher for in vivo- than in vitro-derived embryos. Blastocyst size was approximately 2.3-fold greater in recipients with high compared with normal progesterone. The present study lends strong support to the hypothesis that an earlier rise in progesterone after conception stimulates blastocyst growth and the development of competent embryos.

Conjoined Twins

MedlinePlus

... each other. Conjoined twins develop when an early embryo only partially separates to form two individuals. Although two fetuses will develop from this embryo, they will remain physically connected — most often at ...

Influence of "Solcoseryl" during culture on the sex-dependent repair of bovine demi-embryos.

PubMed

Tominaga, K; Yoneda, K; Utsumi, K

1996-03-01

The purpose of this experiment was to determine the effect of culture conditions on the development of split embryos after bisection and on the sex ratio of resultant bovine demi-embryos. Embryos that had developed into blastocysts on days 6 1/2 to 7 or on days 7 1/2 to 8 from oocytes matured and fertilized in vitro were bisected in BMOC-3 medium supplemented with 33% calf serum. The medium also contained 0%, 0.1% or 1.0% Solcoseryl, a deproteinized hemodialysate product from calf blood. The demi-embryos were first cultured for 4 hours in the same medium in which they had been bisected and then co-cultured with cumulus cells in TCM199 supplemented with 1% calf serum for an additional 20 hr. The rate of production of good to excellent quality demi-embryos obtained from days 6 1/2 to 7 blastocysts was higher than from those on days 7 1/2 to 8. The rate was also significantly improved when blastocysts were bisected in medium containing 0.1% or 1.0% Solcoseryl, compared to the medium without Solcoseryl. Male embryos seemed to recover more rapidly than female embryos, as assessed by morphological quality at 4 hr, although the quality of female embryos had improved by 24 hr. The percentage of males after culture was higher in the medium without Solcoseryl than in its presence. Thus, addition of Solcoseryl at either 0.1% or 1.0% to BMOC-3 medium seemed to improve the production efficiency of good quality demi-embryos, but did not influence the sex ratio. It appears as if female demi-embryos required more time than male embryos to be repaired after bisection.

Metabolite profiling of somatic embryos of Cyclamen persicum in comparison to zygotic embryos, endosperm, and testa

PubMed Central

Winkelmann, Traud; Ratjens, Svenja; Bartsch, Melanie; Rode, Christina; Niehaus, Karsten; Bednarz, Hanna

2015-01-01

Somatic embryogenesis has been shown to be an efficient in vitro plant regeneration system for many crops such as the important ornamental plant Cyclamen persicum, for which this regeneration pathway of somatic embryogenesis is of interest for the vegetative propagation of parental lines as well as elite plants. However, somatic embryogenesis is not commercially used in many crops due to several unsolved problems, such as malformations, asynchronous development, deficiencies in maturation and germination of somatic embryos. In contrast, zygotic embryos in seeds develop and germinate without abnormalities in most cases. Instead of time-consuming and labor-intensive experiments involving tests of different in vitro culture conditions and plant growth regulator supplements, we follow a more directed approach. Zygotic embryos served as a reference and were compared to somatic embryos in metabolomic analyses allowing the future optimization of the in vitro system. The aims of this study were to detect differences in the metabolite profiles of torpedo stage somatic and zygotic embryos of C. persicum. Moreover, major metabolites in endosperm and testa were identified and quantified. Two sets of extracts of two to four biological replicates each were analyzed. In total 52 metabolites were identified and quantified in the different tissues. One of the most significant differences between somatic and zygotic embryos was that the proline concentration in the zygotic embryos was about 40 times higher than that found in somatic embryos. Epicatechin, a scavenger for reactive oxygen species, was found in highest abundance in the testa. Sucrose, the most abundant metabolite was detected in significantly higher concentrations in zygotic embryos. Also, a yet unknown trisaccharide, was significantly enriched in zygotic embryos. PMID:26300898

Effects of fluoride on development and growth of Rana chensinensis embryos and larvae.

PubMed

Chai, Lihong; Dong, Suiming; Zhao, Hongfeng; Deng, Hongzhang; Wang, Hongyuan

2016-04-01

The present study examined the adverse effects of fluoride exposure on embryos and larvae of Rana chensinensis. Survival, morphological abnormalities, growth and development, time to metamorphosis and size at metamorphic climax of R. chensinensis were examined. Our results showed that embryos malformation occurred in all fluoride treatments. Morphological abnormalities of embryos are characterized by axial flexures, the extrusion of fin axis, edema, and ruffled dorsal and ventral fin. Additionally, 4.1mg F(-)/L and above could significantly inhibit embryos growth and development. On day 15, total length and weight of tadpole were significantly lower in 19.6 and 42.4 mg F(-)/L treatments compared to control. However, significant reductions in total length and weight were observed only at 42.4 mg F(-)/L on day 30. Moreover, significant metamorphic delay and decrease in the size at metamorphic climax were found in larvae exposed to 42.4 mg F(-)/L. Taken together, embryos of R. chensinensis are more vulnerable to fluoride exposure than their tadpoles. Our results suggested that the presence of high concentrations fluoride might increase mortality risk and a reduction in juvenile recruitment in the field by increasing embryos malformation, delaying metamorphosis and decreasing size at metamorphosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Pluripotency maintenance in mouse somatic cell nuclear transfer embryos and its improvement by treatment with the histone deacetylase inhibitor TSA.

PubMed

Hai, Tang; Hao, Jie; Wang, Liu; Jouneau, Alice; Zhou, Qi

2011-02-01

Reprogramming of somatic cells to pluripotency can be achieved by nuclear transfer into enucleated oocytes (SCNT). A key event of this process is the demethylation of the Oct4 gene and its temporally and spatially regulated expression. Different studies have shown that it occurs abnormally in some SCNT embryos. TSA is a histone deacetylase inhibitor known to increase the efficiency of development to term of SCNT embryos, but its impact on the developmental features of SCNT embryos is poorly understood. Here, we have followed the fate of the pluripotent cells within SCNT embryos, from the late blastocyst to the early epiblast prior to gastrulation. Our data show a delay in development correlated with a defect in forming and maintaining a correct number of Oct4 expressing ICM and epiblast cells in SCNT embryos. As a consequence, during the outgrowth phase of embryonic stem cell derivation as well as during diapause in vivo, part of the SCNT blastocysts completely lose their ICM cells. Meanwhile, the others display a correctly reprogrammed ICM compatible with the derivation of ES cells and development of the epiblast. Our data also indicate that TSA favors the establishment of pluripotency in SCNT embryos.

2,3,7,8-Tetrachlorodibenzo-p-dioxin induces apoptotic cell death and cytochrome P4501A expression in developing Fundulus heteroclitus embryos

USGS Publications Warehouse

Toomey, B.H.; Bello, S.; Hahn, M.E.; Cantrell, S.; Wright, P.; Tillitt, D.E.; Di Giulio, R.T.

2001-01-01

Fundulus heteroclitus embryos were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during early development using nanoinjection or water bath exposure. TCDD caused developmental abnormalities that included hemorrhaging, loss of vascular integrity, edema, stunted development and death. The LC50 and LD50 of TCDD for Fundulus embryos were ???19.7??9.5 pg TCDD/??l (water bath) and 0.25??0.09 ng TCDD/g embryo (nanoinjection). To identify a possible cause for these developmental abnormalities we analyzed the effects of TCDD on apoptotic cell death and cytochrome P4501A (CYP1A) expression in the embryos. TCDD exposure increased apoptotic cell death in several tissues including brain, eye, gill, kidney, tail, intestine, heart, and vascular tissue. CYP1A expression was also increased in the TCDD-exposed embryos predominantly in liver, kidney, gill, heart, intestine, and in vascular tissues throughout the embryo. There was co-occurrence of TCDD-induced apoptosis and CYP1A expression in some, but not all, cell types. In addition the dose response relationships for apoptosis and mortality were similar, while CYP1A expression appeared more sensitive to TCDD induction. Copyright ?? 2001 Elsevier Science B.V.

Improvement of vitrification of in vitro produced buffalo embryos with special reference to sex ratio following vitrification

PubMed Central

Mahmoud, K. Gh. M; Scholkamy, T. H; Darwish, S. F

2015-01-01

Cryopreservation and sexing of embryos are integrated into commercial embryo transfer technologies. To improve the effectiveness of vitrification of in vitro produced buffalo embryos, two experiments were conducted. The first evaluated the effect of exposure time (2 and 3 min) and developmental stage (morula and blastocysts) on the viability and development of vitrified buffalo embryos. Morphologically normal embryos and survival rates (re-expansion) significantly increased when vitrified morulae were exposed for 2 min compared to 3 min (P<0.001). On the other hand, morphologically normal and survival rates of blastocysts significantly increased when exposed for 3 min compared to 2 min (P<0.001). However, there were no significant differences between the two developmental stages (morulae and blastocystes) in the percentages of morphologically normal embryos and re-expansion rates after a 24 h culture. The second experiment aimed to evaluate the effect of viability on the sex ratio of buffalo embryos after vitrification and whether male and female embryos survived vitrification differently. A total number of 61 blastocysts were vitrified for 3 min with the same cryoprotectant as experiment 1. Higher percentages of males were recorded for live as compared to dead embryos; however, this difference was not significant. In conclusion, the post-thaw survival and development of in vitro produced morulae and blastocysts were found to be affected by exposure time rather than developmental stage. Survivability had no significant effect on the sex ratio of vitrified blastocysts; nevertheless, the number of surviving males was higher than dead male embryos. PMID:27175197

Dechorionation as a tool to improve the fish embryo toxicity test (FET) with the zebrafish (Danio rerio).

PubMed

Henn, Kirsten; Braunbeck, Thomas

2011-01-01

Prior to hatching, the zebrafish embryo is surrounded by an acellular envelope, the chorion. Despite repeated speculations, it could not be clarified unequivocally whether the chorion represents an effective barrier and, thus, protects the embryo from exposure to distinct chemicals. Potentially, there is a risk of generating false negative results in developmental toxicity studies due to limited permeability of the chorion for some compounds. The simplest way to exclude this is to remove the chorion and expose the "naked" embryo. In the context of ecotoxicity testing, standardized protocols do not exist for fish embryo dechorionation, and survival rates of dechorionated embryos have usually not been subjected to statistical analysis. Since reproducibly high survival rates are of fundamental importance for chemical toxicity assessment, the present study was designed to develop and optimize a dechorionation procedure. With appropriate modifications of the fish embryo test protocol, embryos can be dechorionated at 24h post-fertilization (hpf) with survival rates of ≥90%. However, for fish embryo tests with dechorionated embryos, the standard positive control test substance, 3,4-dichloroaniline, should be replaced by another compound, e.g., acetone, since 3,4-dichloroaniline exerts its effects during the first 24h of development. Dechorionation of younger stages (<24 hpf) is generally possible, however with lower survival rates. The effect of dechorionation was demonstrated with the cationic polymer Luviquat HM 552, which is blocked by the chorion non-dechorionated embryos due to its molecular weight of ~400,000 Dalton, but becomes strongly toxic after dechorionation. Copyright © 2010 Elsevier Inc. All rights reserved.

Altered methanol embryopathies in embryo culture with mutant catalase-deficient mice and transgenic mice expressing human catalase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Lutfiya; Wells, Peter G., E-mail: pg.wells@utoronto.ca; Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON

2011-04-01

The mechanisms underlying the teratogenicity of methanol (MeOH) in rodents, unlike its acute toxicity in humans, are unclear, but may involve reactive oxygen species (ROS). Embryonic catalase, although expressed at about 5% of maternal activity, may protect the embryo by detoxifying ROS. This hypothesis was investigated in whole embryo culture to remove confounding maternal factors, including metabolism of MeOH by maternal catalase. C57BL/6 (C57) mouse embryos expressing human catalase (hCat) or their wild-type (C57 WT) controls, and C3Ga.Cg-Catb/J acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug = GD 1),more » exposed for 24 h to 4 mg/ml MeOH or vehicle, and evaluated for functional and morphological changes. hCat and C57 WT vehicle-exposed embryos developed normally. MeOH was embryopathic in C57 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed and turning, whereas hCat embryos were protected. Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to C3H WT controls, suggesting that endogenous ROS are embryopathic. MeOH was more embryopathic in aCat embryos than WT controls, with reduced anterior neuropore closure and head length only in catalase-deficient embryos. These data suggest that ROS may be involved in the embryopathic mechanism of methanol, and that embryonic catalase activity may be a determinant of teratological risk.« less

NanoSMGT: transgene transmission into bovine embryos using halloysite clay nanotubes or nanopolymer to improve transfection efficiency.

PubMed

Campos, Vinicius Farias; de Leon, Priscila Marques Moura; Komninou, Eliza Rossi; Dellagostin, Odir Antônio; Deschamps, João Carlos; Seixas, Fabiana Kömmling; Collares, Tiago

2011-11-01

The objectives were to investigate whether: 1) nanotransfectants are more effective than other common transfection methods for SMGT; 2) NanoSMGT is able to transmit exogenous DNA molecules to bovine embryos; and 3) halloysite clay nanotubes (HCNs) can be used as a transfection reagent to improve transgene transmission. Four transfection systems were used: naked DNA (without transfectant), lipofection, nanopolymer, and halloysite clay nanotubes. Plasmid uptake by sperm and its transfer to embryos were quantified by conventional and real-time PCR, as well as EGFP expression by fluorescence microscopy. Furthermore, sperm motility and viability, and embryo development were investigated. Mean number of plasmids taken up was affected (P < 0.05) by transfection procedure, with the nanopolymer being the most effective transfectant (∼ 153 plasmids per spermatozoon). None of the treatments affected sperm motility or viability. The mean number of plasmids transmitted to four-cell stage embryos was higher (P < 0.05) in nanopolymer and HCNs than liposomes and naked DNA groups. The number of embryos carrying the transgene increased from 8-10% using naked DNA or liposomes to 40-45% using nanopolymer or HCN as transfectants (P < 0.05). There were no significant differences among transfection procedures regarding blastocyst formation rate of resulting embryos. However, no EGFP-expressing embryo was identified in any treatment. Therefore, nanotransfectants improved transgene transmission in bovine embryos without deleterious effects on embryo development. To our knowledge, this was the first time that bovine embryos carrying a transgene were produced by NanoSMGT. Copyright © 2011 Elsevier Inc. All rights reserved.

The early-stage diagnosis of albinic embryos by applying optical coherence tomography

NASA Astrophysics Data System (ADS)

Yang, Bor-Wen; Wang, Shih-Yuan; Wang, Yu-Yen; Cai, Jyun-Jhang; Chang, Chung-Hao

2013-09-01

Albinism is a kind of congenital disease of abnormal metabolism. Poecilia reticulata (guppy fish) is chosen as the model to study the development of albinic embryos as it is albinic, ovoviviparous and with short life period. This study proposed an imaging method for penetrative embryo investigation using optical coherence tomography. By imaging through guppy mother’s reproduction purse, we found the embryo’s eyes were the early-developed albinism features. As human’s ocular albinism typically appear at about four weeks old, it is the time to determine if an embryo will grow into an albino.

Factors affecting the development of somatic cell nuclear transfer embryos in Cattle.

PubMed

Akagi, Satoshi; Matsukawa, Kazutsugu; Takahashi, Seiya

2014-01-01

Nuclear transfer is a complex multistep procedure that includes oocyte maturation, cell cycle synchronization of donor cells, enucleation, cell fusion, oocyte activation and embryo culture. Therefore, many factors are believed to contribute to the success of embryo development following nuclear transfer. Numerous attempts to improve cloning efficiency have been conducted since the birth of the first sheep by somatic cell nuclear transfer. However, the efficiency of somatic cell cloning has remained low, and applications have been limited. In this review, we discuss some of the factors that affect the developmental ability of somatic cell nuclear transfer embryos in cattle.

Retrogressive development: transcendental anatomy and teratology in nineteenth-century Britain.

PubMed

Bates, Alan W H

2014-01-01

In 1855 the leading British transcendental anatomist Robert Knox proposed a theory of retrogressive development according to which the human embryo could give rise to ancestral types or races and the animal embryo to other species within the same family. Unlike monsters attributed to the older theory of arrested development, new forms produced by retrogression were neither imperfect nor equivalent to a stage in the embryo's development. Instead, Knox postulated that embryos contained all possible specific forms in potentia. Retrogressive development could account for examples of atavism or racial throwbacks, and formed part of Knox's theory of rapid (saltatory) species change. Knox's evolutionary theorizing was soon eclipsed by the better presented and more socially acceptable Darwinian gradualism, but the concept of retrogressive development remained influential in anthropology and the social sciences, and Knox's work can be seen as the scientific basis for theories of physical, mental and cultural degeneracy.

Genetics and imaging to assess oocyte and preimplantation embryo health.

PubMed

Warner, C M; Newmark, J A; Comiskey, M; De Fazio, S R; O'Malley, D M; Rajadhyaksha, M; Townsend, D J; McKnight, S; Roysam, B; Dwyer, P J; DiMarzio, C A

2004-01-01

Two major criteria are currently used in human assisted reproductive technologies (ART) to evaluate oocyte and preimplantation embryo health: (1) rate of preimplantation embryonic development; and (2) overall morphology. A major gene that regulates the rate of preimplantation development is the preimplantation embryo development (Ped) gene, discovered in our laboratory. In mice, presence of the Ped gene product, Qa-2 protein, results in a fast rate of preimplantation embryonic development, compared with a slow rate of preimplantation embryonic development for embryos that are lacking Qa-2 protein. Moreover, mice that express Qa-2 protein have an overall reproductive advantage that extends beyond the preimplantation period, including higher survival to birth, higher birthweight, and higher survival to weaning. Data are presented that suggest that Qa-2 increases the rate of development of early embryos by acting as a cell-signalling molecule and that phosphatidylinositol-32 kinase is involved in the cell-signalling pathway. The most likely human homologue of Qa-2 has recently been identified as human leukocyte antigen (HLA)-G. Data are presented which show that HLA-G, like Qa-2, is located in lipid rafts, implying that HLA-G also acts as a signalling molecule. In order to better evaluate the second criterion used in ART (i.e. overall morphology), a unique and innovative imaging microscope has been constructed, the Keck 3-D fusion microscope (Keck 3DFM). The Keck 3DFM combines five different microscopic modes into a single platform, allowing multi-modal imaging of the specimen. One of the modes, the quadrature tomographic microscope (QTM), creates digital images of non-stained transparent cells by measuring changes in the index of refraction. Quadrature tomographic microscope images of oocytes and preimplantation mouse embryos are presented for the first time. The digital information from the QTM images should allow the number of cells in a preimplantation embryo to be counted non-invasively. The Keck 3DFM is also being used to assess mitochondrial distribution in mouse oocytes and embryos by using the k-means clustering algorithm. Both the number of cells in preimplantation embryos and mitochondrial distribution are related to oocyte and embryo health. New imaging data obtained from the Keck 3DFM, combined with genetic and biochemical approaches, have the promise of being able to distinguish healthy from unhealthy oocytes and embryos in a non-invasive manner. The goal is to apply the information from our mouse model system to the clinic in order to identify one and only one healthy embryo for transfer back to the mother undergoing an ART procedure. This approach has the potential to increase the success rate of ART and to decrease the high, and undesirable, multiple birth rate presently associated with ART.

Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

PubMed

Lehner, Adam; Kaszas, Zita; Murber, Akos; Rigo, Janos; Urbancsek, Janos; Fancsovits, Peter

2017-08-01

Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 μl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 μl/embryo), Group 2 with 5-6 (4.2-5.0 μl/embryo), and Group 3 with 7-9 (2.8-3.6 μl/embryo) embryos. Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p < 0.001; D3: 19.7 vs. 27.1 vs. 21.2%; p = 0.029; Group 1. vs. Group 2. vs. Group 3). Cell number on Day 3 differed between Groups 1 and 2 (6.8 ± 2.2; 7.3 ± 2.1; p = 0.004) and Groups 2 and 3 (7.3 ± 2.1 vs. 7.0 ± 2.0; p = 0.014). Culturing 5-6 embryos together in a culture volume of 25 μl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

Characterization of somatic embryo attached structures in Feijoa sellowiana Berg. (Myrtaceae).

PubMed

Correia, Sandra M; Canhoto, Jorge M

2010-06-01

The presence of an attached organ to somatic embryos of angiosperms connecting the embryo to the supporting tissue has been a subject of controversy. This study shows that 67% of the morphologically normal somatic embryos of Feijoa sellowiana possess this type of organ and that its formation was not affected by culture media composition. Histological and ultrastructural analysis indicated that the attached structures of somatic embryos displayed a great morphological diversity ranging from a few cells to massive and columnar structures. This contrast with the simple suspensors observed in zygotic embryos which were only formed by five cells. As well as the suspensor of zygotic embryos, somatic embryo attached structures undergo a process of degeneration in later stages of embryo development. Other characteristic shared by zygotic suspensors and somatic embryo attached structures was the presence of thick cell walls surrounding the cells. Elongated thin filaments were often associated with the structures attached to somatic embryos, whereas in other cases, tubular cells containing starch grains connected the embryo to the supporting tissue. These characteristics associated with the presence of plasmodesmata in the cells of the attached structures seem to indicate a role on embryo nutrition. However, cell proliferation in the attached structures resulting into new somatic embryos may also suggest a more complex relationship between the embryo and the structures connecting it to the supporting tissue.

Tissue densities in developing avian embryos. [under acceleration stresses

NASA Technical Reports Server (NTRS)

Smith, A. H.; Abbott, U. K.; Morzenti, A.

1984-01-01

The density changes in the components of the incubated egg, the embryo, and the embryo's body parts were measured in the course of 21 days of incubation. In the first two-thirds of the incubation period there is a sequence of increasing density among egg contents: amniotic fluid, embryo, yolk, and albumin. As a result, the embryo is located at the bottom of the amniotic fluid, but at the top of the albumin. This position provides the embryo with mechanical protection and a proximity to the egg's air cell. The observed density changes and the asymmetry of these changes among various body parts of the embryo suggest a functional relationship. The density distributions among the body parts are particularly important in gravitational investigations of embryogenesis since they will produce forces tending to dislocate parts of the embryo.

Irreversible barrier to the reprogramming of donor cells in cloning with mouse embryos and embryonic stem cells.

PubMed

Ono, Yukiko; Kono, Tomohiro

2006-08-01

Somatic cloning does not always result in ontogeny in mammals, and development is often associated with various abnormalities and embryo loss with a high frequency. This is considered to be due to aberrant gene expression resulting from epigenetic reprogramming errors. However, a fundamental question in this context is whether the developmental abnormalities reported to date are specific to somatic cloning. The aim of this study was to determine the stage of nuclear differentiation during development that leads to developmental abnormalities associated with embryo cloning. In order to address this issue, we reconstructed cloned embryos using four- and eight-cell embryos, morula embryos, inner cell mass (ICM) cells, and embryonic stem cells as donor nuclei and determined the occurrence of abnormalities such as developmental arrest and placentomegaly, which are common characteristics of all mouse somatic cell clones. The present analysis revealed that an acute decline in the full-term developmental competence of cloned embryos occurred with the use of four- and eight-cell donor nuclei (22.7% vs. 1.8%) in cases of standard embryo cloning and with morula and ICM donor nuclei (11.4% vs. 6.6%) in serial nuclear transfer. Histological observation showed abnormal differentiation and proliferation of trophoblastic giant cells in the placentae of cloned concepti derived from four-cell to ICM cell donor nuclei. Enlargement of placenta along with excessive proliferation of the spongiotrophoblast layer and glycogen cells was observed in the clones derived from morula embryos and ICM cells. These results revealed that irreversible epigenetic events had already started to occur at the four-cell stage. In addition, the expression of genes involved in placentomegaly is regulated at the blastocyst stage by irreversible epigenetic events, and it could not be reprogrammed by the fusion of nuclei with unfertilized oocytes. Hence, developmental abnormalities such as placentomegaly as well as embryo loss during development may occur even in cloned embryos reconstructed with nuclei from preimplantation-stage embryos, and these abnormalities are not specific to somatic cloning.

HIGHLY METHYL ESTERIFIED SEEDS is a pectin methyl esterase involved in embryo development.

PubMed

Levesque-Tremblay, Gabriel; Müller, Kerstin; Mansfield, Shawn D; Haughn, George W

2015-03-01

Homogalacturonan pectin domains are synthesized in a highly methyl-esterified form that later can be differentially demethyl esterified by pectin methyl esterase (PME) to strengthen or loosen plant cell walls that contain pectin, including seed coat mucilage, a specialized secondary cell wall of seed coat epidermal cells. As a means to identify the active PMEs in seed coat mucilage, we identified seven PMEs expressed during seed coat development. One of these, HIGHLY METHYL ESTERIFIED SEEDS (HMS), is abundant during mucilage secretion, peaking at 7 d postanthesis in both the seed coat and the embryo. We have determined that this gene is required for normal levels of PME activity and homogalacturonan methyl esterification in the seed. The hms-1 mutant displays altered embryo morphology and mucilage extrusion, both of which are a consequence of defects in embryo development. A significant decrease in the size of cells in the embryo suggests that the changes in embryo morphology are a consequence of lack of cell expansion. Progeny from a cross between hms-1 and the previously characterized PME inhibitor5 overexpression line suggest that HMS acts independently from other cell wall-modifying enzymes in the embryo. We propose that HMS is required for cell wall loosening in the embryo to facilitate cell expansion during the accumulation of storage reserves and that its role in the seed coat is masked by redundancy. © 2015 American Society of Plant Biologists. All Rights Reserved.

Gene expression patterns during somatic embryo development and germination in maize Hi II callus cultures.

PubMed

Che, Ping; Love, Tanzy M; Frame, Bronwyn R; Wang, Kan; Carriquiry, Alicia L; Howell, Stephen H

2006-09-01

Gene expression patterns were profiled during somatic embryogenesis in a regeneration-proficient maize hybrid line, Hi II, in an effort to identify genes that might be used as developmental markers or targets to optimize regeneration steps for recovering maize plants from tissue culture. Gene expression profiles were generated from embryogenic calli induced to undergo embryo maturation and germination. Over 1,000 genes in the 12,060 element arrays showed significant time variation during somatic embryo development. A substantial number of genes were downregulated during embryo maturation, largely histone and ribosomal protein genes, which may result from a slowdown in cell proliferation and growth during embryo maturation. The expression of these genes dramatically recovered at germination. Other genes up-regulated during embryo maturation included genes encoding hydrolytic enzymes (nucleases, glucosidases and proteases) and a few storage genes (an alpha-zein and caleosin), which are good candidates for developmental marker genes. Germination is accompanied by the up-regulation of a number of stress response and membrane transporter genes, and, as expected, greening is associated with the up-regulation of many genes encoding photosynthetic and chloroplast components. Thus, some, but not all genes typically associated with zygotic embryogenesis are significantly up or down-regulated during somatic embryogenesis in Hi II maize line regeneration. Although many genes varied in expression throughout somatic embryo development in this study, no statistically significant gene expression changes were detected between total embryogenic callus and callus enriched for transition stage somatic embryos.

Effect of micro-vibration culture system on embryo development.

PubMed

Hur, Yong Soo; Park, Jeong Hyun; Ryu, Eun Kyung; Park, Sung Jin; Lee, Jun Ho; Lee, Soo Hee; Yoon, Jung; Yoon, San Hyun; Hur, Chang Young; Lee, Won Don; Lim, Jin Ho

2013-06-01

Micro-vibration culture system was examined to determine the effects on mouse and human embryo development and possible improvement of clinical outcomes in poor responders. The embryonic development rates and cell numbers of blastocysts were compared between a static culture group (n = 178) and a micro-vibration culture group (n = 181) in mice. The embryonic development rates and clinical results were compared between a static culture group (n = 159 cycles) and a micro-vibration culture group (n = 166 cycles) in poor responders. A micro-vibrator was set at a frequency of 42 Hz, 5 s/60 min duration for mouse and human embryo development. The embryonic development rate was significantly improved in the micro-vibration culture group in mice (p < 0.05). The cell numbers of mouse blastocysts were significantly higher in the micro-vibration group than in the static culture group (p < 0.05). In the poor responders, the rate of high grade embryos was not significantly improved in the micro-vibration culture group on day 3. However, the optimal embryonic development rate on day 5 was improved in the micro-vibration group, and the total pregnancy rate and implantation rate were significantly higher in the micro-vibration group than in the static culture group (p < 0.05). Micro-vibration culture methods have a beneficial effect on embryonic development in mouse embryos. In poor responders, the embryo development rate was improved to a limited extent under the micro-vibration culture conditions, but the clinical results were significantly improved.

Effects of gravity perturbation on developing animal systems

NASA Technical Reports Server (NTRS)

Malacinski, G. M.; Neff, A. W.

1986-01-01

The use of developing animal systems to analyze the effects of microgravity on animals is discussed. Some of the key features of developing systems, especially embryos, are reviewed and relevant space data are summarized. Issues to be addressed in the design of future space experiments are discussed. It is noted that an embryo which exhibits ground based gravity effects should be selected for use as a model system and individual variation in gravity response among batches of embryos should be taken into account.

Studies of Weak, ELF Electromagnetic Fields Effects on the Early Embryonic Development

DTIC Science & Technology

1988-12-29

characters: - General aspect: stage; size of the embryo; size of the head relatively to the trunk. - Head : morphology of the skull; development of...the eyes; size and morphology of the beak; size of the neck . - Trunk: morphology of the vertebral column; development of the tail; closure of thorax and...mishandled, the orientation of the embryo was not taken into account. As indicated in Fig. 7, the head -tail axis orientation of an embryo was North (N

Developments in the storage of embryos in France and the limitations of the laws of bioethics. Analysis of procedures in 17 storage centres and the destiny of stored embryos.

PubMed

Moutel, Grégoire; Gregg, Edna; Meningaud, Jean Paul; Hervé, Christian

2002-01-01

1985 witnessed the first transfers of frozen embryos resulting in live births in France. Since this time the number of embryos obtained by in vitro fertilisation (IVF) has increased each year. In 1999 each IVF attempt obtains, on average, 4.5 embryos that can be successfully implanted. In this paper we consider only those couples who have successfully obtained embryos (either by ICSI or traditional IVF techniques). The aims of the study are: To show how developments in embryo production and conservation have influenced the number of embryos stored. To address the socio-medical and ethical issues raised and to provide practitioners with some thoughts for reflection when consulting with couples based on the study findings To discuss the results of our findings in the light of those ethical questions raised by the imminent revision of the Laws of Bioethics. In the first instance we did a retrospective analysis of quantitative data that 17 storage centres had collected over a period of 5 years. This period was marked by the implementation in 1994 of Laws described as Bioethics' Laws in France. During a second period we conducted a qualitative study regarding the fate of stored embryos. In order to do this, we began an analysis of the "status" of embryos and the decisions of those couples whose embryos were still in storage. For this a questionnaire was used. The number of embryos that remain in storage in the 17 storage centres has increased reaching a total of 17,592 embryos involving 3,888 couples. The results show a consistent and persistent increase in the number of embryos stored before and after 1994. The qualitative study shows that: 51% of couples with embryos in storage can no longer be found, 23.6% request a continuance of storage, 12% would accept donating their embryos to medical research, 9.1% would wish for other couples to take eventual ownership of the embryo in 7.2% of cases the storage centre has can provide no information concerning the continuing of storage of such embryos. The Bioethics Laws have therefore not succeeded in limiting the inflation in the number of embryos stored despite that the fact that this was one of the major concerns of those involved in formulating the laws and the medical professionals involved. Our study shows that the guidelines provided by these Laws remain ambiguous and that the objectives defined therein are thus difficult to achieve. Our study highlights the impact of such developments on the possible eventual "destiny" of such embryos, the behaviour of and the advice provided to couples, and the management practice of the storage centres involved. We present these results in the light of the laws established in 1994 in order to define not only the benefits but also the potential limitations of such legislation. No guidelines were laid down regarding the future of embryos belonging to a couple that no longer wishes to embark upon a "parental project". As a result it is not possible to terminate the conservation of such embryos which therefore remain in storage awaiting the revision of the current laws. The major objectives of our study assess the impact of the Laws and their impact on practice and to contribute to the debate which has yet to take place in the social and political arena.

Accurate and Phenol Free DNA Sexing of Day 30 Porcine Embryos by PCR.

PubMed

Blanes, Milena S; Tsoi, Stephen C M; Dyck, Michael K

2016-02-14

Research into prenatal programming in the pig has shown that the sex of the developing embryo or fetus can influence the developmental outcome. Therefore, the ability to determine an embryo's sex is necessary in many experiments particularly regarding early development. The present protocol demonstrates an inexpensive, rapid and non-toxic preparation of pig genomic DNA for use with PCR. Day 30 embryos must be humanely collected according to the guidelines established by Institutional Animal Policy and Welfare Committees for the present protocol. The preparation of the whole embryo for this PCR based sexing technique simply involves grinding the frozen embryo to a fine powder using a pre-chilled mortar and pestle. PCR-quality DNA is released from a small amount of embryo powder by applying a hot incubation in an alkaline lysis reagent. Next, the DNA solution is mixed with neutralization buffer and used directly for PCR. Two primer pairs are generated to detect specific sex determining region of the Y- chromosome (SRY) and ZFX region of the X- chromosome with high accuracy and specificity. The same protocol can be applied to other elongated embryos (Day 10 to Day 14) earlier than Day 30. Also, this protocol can be carried with 96-welled plates when screening a large number of embryos, making it feasible for automation and high-throughput sex typing.

Accurate and Phenol Free DNA Sexing of Day 30 Porcine Embryos by PCR

PubMed Central

Dyck, Michael K.

2016-01-01

Research into prenatal programming in the pig has shown that the sex of the developing embryo or fetus can influence the developmental outcome. Therefore, the ability to determine an embryo's sex is necessary in many experiments particularly regarding early development. The present protocol demonstrates an inexpensive, rapid and non-toxic preparation of pig genomic DNA for use with PCR. Day 30 embryos must be humanely collected according to the guidelines established by Institutional Animal Policy and Welfare Committees for the present protocol. The preparation of the whole embryo for this PCR based sexing technique simply involves grinding the frozen embryo to a fine powder using a pre-chilled mortar and pestle. PCR-quality DNA is released from a small amount of embryo powder by applying a hot incubation in an alkaline lysis reagent. Next, the DNA solution is mixed with neutralization buffer and used directly for PCR. Two primer pairs are generated to detect specific sex determining region of the Y- chromosome (SRY) and ZFX region of the X- chromosome with high accuracy and specificity. The same protocol can be applied to other elongated embryos (Day 10 to Day 14) earlier than Day 30. Also, this protocol can be carried with 96-welled plates when screening a large number of embryos, making it feasible for automation and high-throughput sex typing. PMID:26966900

Use of blue crab (Callinectes sapidus) embryos for toxicity testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, R.; O`Malley, K.

1995-12-31

After fertilization, blue crab embryos develop in egg sacs attached to the female pleopods, often referred to as the sponge. Lipovitellin and lipid droplets in the egg sacs provide energy and nutrition for the developing embryos. Embryos were removed from the sponge and transferred to 24 well culture plates containing sea water with or without toxicants, Each well contained 10 embryos. After 7 to 10 days, embryos hatched to swimming zoea. The effects of toxicants at various concentrations on hatching were determined and the EC{sub 50} calculated. For example, the EC{sub 50} for tributyltin, fenvalerate and mercuric chloride were 50,more » 30 and 90 ng/liter, respectively. The hatching success of control embryos ranged from 95 to 98%. Formation of the heart, eyespot formation, appendage formation and utilization rate of lipovitellin were also effected by exposure to toxicants. At a low concentration of mercuric ion (30ng/liter) the heart formed, but there was no heart beat. Eyespot formation was abnormal in the presence of high concentrations of cadmium (2 {micro}g/liter) and zinc (5 {micro}g/liter), Crab embryos offer many advantages for toxicity testing of pure compounds or mixtures in water, including toxicity testing of sediment pore water. The crab embryos may also serve as models to understand the effect of specific toxicants on the heart and eye spots of crustaceans.« less

Unraveling the association between genetic integrity and metabolic activity in pre-implantation stage embryos

PubMed Central

D’Souza, Fiona; Pudakalakatti, Shivanand M.; Uppangala, Shubhashree; Honguntikar, Sachin; Salian, Sujith Raj; Kalthur, Guruprasad; Pasricha, Renu; Appajigowda, Divya; Atreya, Hanudatta S.; Adiga, Satish Kumar

2016-01-01

Early development of certain mammalian embryos is protected by complex checkpoint systems to maintain the genomic integrity. Several metabolic pathways are modulated in response to genetic insults in mammalian cells. The present study investigated the relationship between the genetic integrity, embryo metabolites and developmental competence in preimplantation stage mouse embryos with the aim to identify early biomarkers which can predict embryonic genetic integrity using spent medium profiling by NMR spectroscopy. Embryos carrying induced DNA lesions (IDL) developed normally for the first 2.5 days, but began to exhibit a developmental delay at embryonic day 3.5(E3.5) though they were morphologically indistinguishable from control embryos. Analysis of metabolites in the spent medium on E3.5 revealed a significant association between pyruvate, lactate, glucose, proline, lysine, alanine, valine, isoleucine and thymine and the extent of genetic instability observed in the embryos on E4.5. Further analysis revealed an association of apoptosis and micronuclei frequency with P53 and Bax transcripts in IDL embryos on the E4.5 owing to delayed induction of chromosome instability. We conclude that estimation of metabolites on E3.5 in spent medium may serve as a biomarker to predict the genetic integrity in pre-implantation stage embryos which opens up new avenues to improve outcomes in clinical IVF programs. PMID:27853269

The Effects of Calcitonin on the Development of and Ca2+ Levels in Heat-shocked Bovine Preimplantation Embryos In Vitro

PubMed Central

KAMANO, Shumpei; IKEDA, Shuntaro; SUGIMOTO, Miki; KUME, Shinichi

2014-01-01

Intracellular calcium homeostasis is essential for proper cell function. We investigated the effects of heat shock on the development of and the intracellular Ca2+ levels in bovine preimplantation embryos in vitro and the effects of calcitonin (CT), a receptor-mediated Ca2+ regulator, on heat shock-induced events. Heat shock (40.5 C for 10 h between 20 and 30 h postinsemination) of in vitro-produced bovine embryos did not affect the cleavage rate; however, it significantly decreased the rates of development to the 5- to 8-cell and blastocyst stages as compared with those of the control cultured for the entire period at 38.5 C (P < 0.05). The relative intracellular Ca2+ levels at the 1-cell stage (5 h after the start of heat shock), as assessed by Fluo-8 AM, a fluorescent probe for Ca2+, indicated that heat shock significantly lowered the Ca2+ level as compared with the control level. Semiquantitative reverse transcription PCR and western blot analyses revealed the expression of CT receptor in bovine preimplantation embryos. The addition of CT (10 nM) to the culture medium ameliorated the heat shock-induced impairment of embryonic development beyond the 5- to 8-cell stage. The Ca2+ level in the heat-shocked embryos cultured with CT was similar to that of the control embryos, suggesting that heat shock lowers the Ca2+ level in fertilized embryos in vitro and that a lower Ca2+ level is implicated in heat shock-induced impairment of embryonic development. Intracellular Ca2+-mobilizing agents, e.g., CT, may effectively circumvent the detrimental effects of heat shock on early embryonic development. PMID:24899099

Subacute developmental exposure of zebrafish to the organophosphate pesticide metabolite, chlorpyrifos-oxon, results in defects in Rohon-Beard sensory neuron development

PubMed Central

Jacobson, Saskia M.; Birkholz, Denise A.; McNamara, Marcy L.; Bharate, Sandip B.; George, Kathleen M.

2010-01-01

Organophosphate pesticides (OPs) are environmental toxicants known to inhibit the catalytic activity of acetylcholinesterase (AChE) resulting in hypercholinergic toxicity symptoms. In developing embryos, OPs have been hypothesized to affect both cholinergic and non-cholinergic pathways. In order to understand the neurological pathways affected by OP exposure during embryogenesis, we developed a subacute model of OP developmental exposure in zebrafish by exposing embryos to a dose of the OP metabolite chlorpyrifos oxon (CPO) that is non-lethal and significantly inhibited AChE enzymatic activity compared to control embryos (43% at 1 day post-fertilization (dpf) and 11% at 2 dpf). Phenotypic analysis of CPO-exposed embryos demonstrated that embryonic growth, as analyzed by gross morphology, was normal in 85% of treated embryos. Muscle fiber formation was similar to control embryos as analyzed by birefringence, and nicotinic acetylcholine receptor (nAChR) cluster formation was quantitatively similar to control embryos as analyzed by α-bungarotoxin staining. These results indicate that partial AChE activity during the early days of zebrafish development is sufficient for general development, muscle fiber, and nAChR development. Rohon-Beard (RB) sensory neurons exhibited aberrant peripheral axon extension and gene expression profiling suggests that several genes responsible for RB neurogenesis are down-regulated. Stability of CPO in egg water at 28.5 °C was determined by HPLC-UV-MS analysis which revealed that the CPO concentration used in our studies hydrolyzes in egg water with a half-life of one day. The result that developmental CPO exposure affected RB neurogenesis without affecting muscle fiber or nAChR cluster formation demonstrates that zebrafish are a strong model system for characterizing subtle neurological pathologies resulting from environmental toxicants. PMID:20701988

Effect of supplemented sericin on the development, cell number, cryosurvival and number of lipid droplets in cultured bovine embryos.

PubMed

Hosoe, Misa; Inaba, Yasushi; Hashiyada, Yutaka; Imai, Kei; Kajitani, Kenji; Hasegawa, Yuichi; Irie, Mamoru; Teramoto, Hidetoshi; Takahashi, Toru; Niimura, Sueo

2017-02-01

Sericin was investigated as an alternative to fetal bovine serum (FBS) for bovine embryo culture. In vitro matured oocytes were developed using 0.05%, 0.1% or 0.15% sericin. The developmental rate, cryosurvival rate and blastulation time of these embryos were compared with those of embryos developed using 5% FBS. The number of lipid droplets was compared among the blastocysts developed using 5% FBS, using 0.05% sericin and in vivo. The rate of cleavage and blastocyst formation was similar among all groups. Blastulation occurred significantly earlier in the embryos developed using 5% FBS than in those developed using sericin at any concentration (P < 0.05). At 72 h after thawing, the cryosurvival rate of the blastocysts developed using 5% FBS and 0.05% sericin were significantly higher compared with those developed using 0.1% and 0.15% sericin (P < 0.05). The blastocysts developed using 0.05% sericin and in vivo produced a significantly fewer number of medium and large lipid droplets than those developed using 5% FBS. These results suggest that the blastocysts developed using 0.05% sericin show characteristics similar to those of the blastocysts developed in vivo and that the use of sericin as an alternative to FBS is feasible. © 2016 Japanese Society of Animal Science.

Culture of bovine embryos in deproteinized hemodialysate-supplemented media and immature mouse uterine horns.

PubMed

Thuemmel, A E; Gwazdauskas, F C; Canseco, R S; Pearson, R E; Jochle, W

1991-06-01

Bovine morulae (d 6) were used to evaluate embryonic development in a deproteinized hemodialysate, agar embedding, and in the uterus of the immature mouse. Agar-embedded embryos were cultured in Ham's F-10 and 10% steer serum either (treatment 1) immediately after collection or (treatment 2) 24 h after storage in the uterus of the immature mouse. Unembedded embryos were cultured in Ham's F-10 containing (treatment 3) 10% steer serum, (treatment 4) 1% deproteinized hemodialysate CLB1107, or (treatment 5) 1% de-proteinized hemodialysate CLB1107 and 10% steer serum. A greater percentage of the embryos reached the hatched blastocyst stage after culture in treatments 1, 3, 4, and 5 (38.1, 34.6, 28.6, and 21.1%) than in treatment 2 (9.5%) in which embryos were stored in the immature mouse uterus for 24 h prior to in vitro culture. Final development scores for unembedded and agar-embedded embryos cultured in Ham's F-10 (5.5 +/- .3) and 10% steer serum (4.9 +/- .4) were similar and higher than those of embryos cultured in deproteinized hemodialysate CLB1107 (4.2 +/- .4), deproteinized hemodialysate CLB1107 and steer serum (4.2 +/- .4), or immature mouse uteri (3.4 +/- .4). It is concluded that deproteinized hemodialysate supplementation at 1% (vol/vol) failed to enhance embryonic development in vitro. Moreover, bovine morulae were unaffected by agar embedding and were able to develop to a limited extent following short-term storage in the uterus of the immature mouse.

An experimental test and models of drift and dispersal processes of pallid sturgeon (Scaphirhynchus albus) free embryos in the Missouri River

USGS Publications Warehouse

Braaten, P.J.; Fuller, D.B.; Lott, R.D.; Ruggles, M.P.; Brandt, T.F.; Legare, R.G.; Holm, R.J.

2012-01-01

Free embryos of wild pallid sturgeon Scaphirhynchus albus were released in the Missouri River and captured at downstream sites through a 180-km reach of the river to examine ontogenetic drift and dispersal processes. Free embryos drifted primarily in the fastest portion of the river channel, and initial drift velocities for all age groups (mean = 0.66–0.70 m s−1) were only slightly slower than mean water column velocity (0.72 m s−1). During the multi-day long-distance drift period, drift velocities of all age groups declined an average of 9.7% day−1. Younger free embryos remained in the drift upon termination of the study; whereas, older age groups transitioned from drifting to settling during the study. Models based on growth of free embryos, drift behavior, size-related variations in drift rates, and channel hydraulic characteristics were developed to estimate cumulative distance drifted during ontogenetic development through a range of simulated water temperatures and velocity conditions. Those models indicated that the average free embryo would be expected to drift several hundred km during ontogenetic development. Empirical data and model results highlight the long-duration, long-distance drift and dispersal processes for pallid sturgeon early life stages. In addition, results provide a likely mechanism for lack of pallid sturgeon recruitment in fragmented river reaches where dams and reservoirs reduce the length of free-flowing river available for pallid sturgeon free embryos during ontogenetic development.

Effect on embryos of injection of phosphorothioate-modified oligonucleotides into pregnant mice.

PubMed

Gaudette, M F; Hampikian, G; Metelev, V; Agrawal, S; Crain, W R

1993-01-01

Phosphorothioate-modified oligonucleotides were injected into pregnant female mice to assess the effect on developing embryos. Injections were carried out during two different time periods, one when embryos were in preimplantation stages of development (about 3.5 days of development) and the other after implantation, when both a fetus and placenta are present (from days 9.5 to 11.5 of development). Three different phosphorothioate-modified oligonucleotides were injected. One, which had a sequence not present in the mouse genome, was used to ask whether nonspecific toxic or teratogenic effects on embryos result from treatment of the mother. A second was complementary to the mRNA of the testis-determining factor gene Sry and was used to ask whether a specific developmental pathway (i.e., sex determination) could be disrupted in embryos in vivo. The third was the complement of the anti-Sry sequence. None of these oligonucleotides reduced the frequency of successful pregnancy after mating or the average litter size from that observed in controls animals. Furthermore, examination of 291 pups or fetuses from all oligonucleotide-injected pregnant females revealed no developmental defects regardless of which sequence was used. It is concluded that injection of phosphorothioate-modified oligonucleotides into pregnant females according to the protocols described here is not toxic or teratogenic to embryos in a nonspecific way. Also, anti-Sry oligonucleotides did not influence sex determination in embryos, although there are several possible explanations for this.

[Relationship between mitochondrial DNA copy number, membrane potential of human embryo and embryo morphology].

PubMed

Zhao, H; Teng, X M; Li, Y F

2017-11-25

Objective: To explore the relationship between the embryo with the different morphological types in the third day and its mitochondrial copy number, the membrane potential. Methods: Totally 117 embryos with poor development after normal fertilization and were not suitable transferred in the fresh cycle and 106 frozen embryos that were discarded voluntarily by infertility patients with in vitro fertilization-embryo transfer after successful pregnancy were selected. According to evaluation of international standard in embryos, all cleavage stage embryos were divided into class Ⅰ frozen embryo group ( n= 64), class Ⅱ frozen embryo group ( n= 42) and class Ⅲ fresh embryonic group (not transplanted embryos; n= 117). Real-time PCR and confocal microscopy methods were used to detect mitochondrial DNA (mtDNA) copy number and the mitochondrial membrane potential of a single embryo. The differences between embryo quality and mtDNA copy number and membrane potential of each group were compared. Results: The copy number of mtDNA and the mitochondrial membrane potential in class Ⅲ fresh embryonic group [(1.7±1.0)×10(5) copy/μl, 1.56±0.32] were significantly lower than those in class Ⅰ frozen embryo group [(3.4±1.7)×10(5) copy/μl, 2.66±0.21] and class Ⅱ frozen embryo group [(2.6±1.2)×10(5) copy/μl, 1.80±0.32; all P< 0.05]. The copy number of mtDNA and the mitochondrial membrane potential in classⅠ frozen embryo group were significantly higher than those in classⅡ frozen embryo group (both P< 0.05). Conclusion: The mtDNA copy number and the mitochondrial membrane potential of embryos of the better quality embryo are higher.

The Effects of Di-(2-ethylhexyl)-phthalate Exposure on Fertilization and Embryonic Development In Vitro and Testicular Genomic Mutation In Vivo

PubMed Central

Gu, Yi-Hua; Liu, Miao; Xu, Yan; Yuan, Yao; Sun, Fei; Zhang, Hui-Qin; Shi, Hui-Juan

2012-01-01

The present study was undertaken to determine the reproductive hazards of Di-(2-ethylhexyl)-phthalate (DEHP) on mouse spermatozoa and embryos in vitro and genomic changes in vivo. Direct low-level DEHP exposure (1 μg/ml) on spermatozoa and embryos was investigated by in vitro fertilization (IVF) process, culture of preimplanted embryos in DEHP-supplemented medium and embryo transfer to achieve full term development. Big Blue® transgenic mouse model was employed to evaluate the mutagenesis of testicular genome with in vivo exposure concentration of DEHP (500 mg/kg/day). Generally, DEHP-treated spermatozoa (1 μg/ml, 30 min) presented reduced fertilization ability (P<0.05) and the resultant embryos had decreased developmental potential compared to DMSO controls (P<0.05). Meanwhile, the transferred 2-cell stage embryos derived from treated spermatozoa also exhibited decreased birth rate than that of control (P<0.05). When fertilized oocytes or 2-cell stage embryos were recovered by in vivo fertilization (without treatment) and then exposed to DEHP, the subsequent development proceed to blastocysts was different, fertilized oocytes were significantly affected (P<0.05) whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05). Testes of the Big Blue® transgenic mice treated with DEHP for 4 weeks indicated an approximately 3-fold increase in genomic DNA mutation frequency compared with controls (P<0.05). These findings unveiled the hazardous effects of direct low-level exposure of DEHP on spermatozoa's fertilization ability as well as embryonic development, and proved that in vivo DEHP exposure posed mutagenic risks in the reproductive organ – at least in testes, are of great concern to human male reproductive health. PMID:23226291

The effects of Di-(2-ethylhexyl)-phthalate exposure on fertilization and embryonic development in vitro and testicular genomic mutation in vivo.

PubMed

Huang, Xue-Feng; Li, Yan; Gu, Yi-Hua; Liu, Miao; Xu, Yan; Yuan, Yao; Sun, Fei; Zhang, Hui-Qin; Shi, Hui-Juan

2012-01-01

The present study was undertaken to determine the reproductive hazards of Di-(2-ethylhexyl)-phthalate (DEHP) on mouse spermatozoa and embryos in vitro and genomic changes in vivo. Direct low-level DEHP exposure (1 μg/ml) on spermatozoa and embryos was investigated by in vitro fertilization (IVF) process, culture of preimplanted embryos in DEHP-supplemented medium and embryo transfer to achieve full term development. Big Blue® transgenic mouse model was employed to evaluate the mutagenesis of testicular genome with in vivo exposure concentration of DEHP (500 mg/kg/day). Generally, DEHP-treated spermatozoa (1 μg/ml, 30 min) presented reduced fertilization ability (P<0.05) and the resultant embryos had decreased developmental potential compared to DMSO controls (P<0.05). Meanwhile, the transferred 2-cell stage embryos derived from treated spermatozoa also exhibited decreased birth rate than that of control (P<0.05). When fertilized oocytes or 2-cell stage embryos were recovered by in vivo fertilization (without treatment) and then exposed to DEHP, the subsequent development proceed to blastocysts was different, fertilized oocytes were significantly affected (P<0.05) whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05). Testes of the Big Blue® transgenic mice treated with DEHP for 4 weeks indicated an approximately 3-fold increase in genomic DNA mutation frequency compared with controls (P<0.05). These findings unveiled the hazardous effects of direct low-level exposure of DEHP on spermatozoa's fertilization ability as well as embryonic development, and proved that in vivo DEHP exposure posed mutagenic risks in the reproductive organ - at least in testes, are of great concern to human male reproductive health.

Developmental and reproductive toxicity of PVP/PEI-coated silver nanoparticles to zebrafish.

PubMed

Orbea, Amaia; González-Soto, Nagore; Lacave, José María; Barrio, Irantzu; Cajaraville, Miren P

2017-09-01

Cellular and molecular mechanisms of toxicity of silver nanoparticles (NPs) and their toxicity to fish embryos after waterborne exposure have been widely investigated, but much less information is available regarding the effect of Ag NPs on physiological functions such as growth or reproduction. In this work, the effects of waterborne exposure of adult zebrafish (Danio rerio) to PVP/PEI coated Ag NPs (~5nm) on reproduction (fecundity) were investigated. Moreover, the development of the embryos after parental exposure was compared with the development of embryos after direct waterborne exposure to the NPs. For this, two experiments were run: 1) embryos from unexposed parents were treated for 5days with Ag NPs (10μgAgL -1 -10mgAgL -1 ) and development was monitored, and 2) selected breeding zebrafish were exposed for 3weeks to 100ngAgL -1 (environmentally relevant concentration) or to 10μgAgL -1 of Ag NPs, fecundity was scored and development of resulting embryos was monitored up to 5days. Waterborne exposure of embryos to Ag NPs resulted in being highly toxic (LC50 at 120h=50μgAgL -1 ), causing 100% mortality during the first 24h of exposure at 0.1mgAgL -1 . Exposure of adults, even at the environmentally relevant silver concentration, caused a significant reduction of fecundity by the second week of treatment and resulting embryos showed a higher prevalence of malformations than control embryos. Exposed adult females presented higher prevalence of vacuolization in the liver. These results show that Ag NPs at an environmentally relevant concentration are able to affect population level parameters in zebrafish. Copyright © 2017 Elsevier Inc. All rights reserved.

Capacitive detection of micromotions: Monitoring ballistics of a developing avian embryo

NASA Astrophysics Data System (ADS)

Szymanski, Jan A.; Pawlak, Krzysztof; Wasowicz, Pawel; Moscicki, Jozef K.

2002-09-01

An instrument for noninvasive monitoring of very weak biomechanical activities of small living organisms is described. The construction is sufficiently flexible to permit a range of studies including developing embryos of oviparous animals, pests that live in loose materials and timber, and insects that develop in cocoons. Motions are detected by monitoring a current generated by the fluctuating position of the object-loaded electrode of a capacitive sensor. To maximize the signal, oscillations of the electrode are mechanically enhanced and the current is amplified and filtered by a two-stage signal amplifier and a bank of six active Butterworth filters. The device is optimized to ballistocardiography of hen embryos. The sensitivity achieved makes possible quantitative studies of heart activity of 7-day-old embryos.

Methods for conducting bioassays using embryos and larvae of Pacific herring, Clupea pallasi.

PubMed

Dinnel, Paul A; Middaugh, Douglas P; Schwarck, Nathan T; Farren, Heather M; Haley, Richard K; Hoover, Richard A; Elphick, James; Tobiason, Karen; Marshall, Randall R

2011-02-01

The rapid decrease of several stocks of Pacific herring, Clupea pallasi, in Puget Sound, Washington, has led to concerns about the effects of industrial and nonpoint source contamination on the embryo and larval stages of this and related forage fish species. To address these concerns, the state of Washington and several industries have funded efforts to develop embryo and larval bioassay protocols that can be used by commercial laboratories for routine effluent testing. This article presents the results of research to develop herring embryo and larval bioassay protocols. Factors evaluated during protocol development included temperature, salinity, dissolved oxygen (DO), light intensity, photoperiod, larval feeding regimes, use of brine and artificial sea salts, gonad sources, collection methods, and egg quality.

Developmental kinetics of pig embryos by parthenogenetic activation or by handmade cloning.

PubMed

Li, J; Li, R; Liu, Y; Villemoes, K; Purup, S; Callesen, H

2013-10-01

The developmental kinetics of pig embryos produced by parthenogenetic activation without (PAZF) or with (PAZI) zona pellucida or by handmade cloning (HMC) was compared by time-lapse videography. After cumulus cell removal, the matured oocytes were either left zona intact (PAZI) or were made zona free by pronase digestion (PAZF) before they were activated (PA). Other matured oocytes were used for HMC based on foetal fibroblast cells. On Day 0 (day of PA or reconstruction), the embryos were cultured for 7 days in vitro in our time-lapse system. Pictures were taken every 30 min, and afterwards, each cell cycle was identified for each embryo to be analysed. Results showed that the PA embryos (both PAZF and PAZI) had shorter first cell cycle compared with HMC (17.4. 17.8 vs 23.6 h), but had a longer time length from four cell to morula stages (57.9, 53.8 vs 44.9 h). However, at the second cell cycle, PAZF embryos needed shorter time, while PAZI embryos had similar time length as HMC embryos, and both were longer than PAZF (23.4, 24.8 vs 14.6 h). Both PAZF and PAZI embryos used similar time to reach the blastocyst stage, and this was later than HMC embryos. In addition, when all of these embryos were grouped into viable (developed to blastocysts) and non-viable (not developed to blastocysts), the only difference in the time length was observed on the first cell cycle (18.6 vs 24.5 h), but not on the later cell cycles. In conclusion, our results not only give detailed information regarding the time schedule of in vitro-handled pig embryos, but also indicate that the first cell cycle could be used as a selecting marker for embryo viability. However, to evaluate the effect of the produced techniques, the whole time schedule of the pre-implantation developmental kinetics should be observed. © 2013 Blackwell Verlag GmbH.

Parental genetic material and oxygen concentration affect hatch dynamics of mouse embryo in vitro.

PubMed

Zhan, Shaoquan; Cao, Shanbo; Du, Hongzi; Sun, Yuan; Li, Li; Ding, Chenhui; Zheng, Haiyan; Huang, Junjiu

2018-04-21

Hatching is crucial for mammalian embryo implantation, since difficulties during this process can lead to implantation failure, ectopic pregnancy and consequent infertility. Despite years of intensive researches, how internal and external factors affecting embryo hatch are still largely unclear. The effects of parental genetic material and oxygen concentration on hatch process were examined. Fertilized and parthenogenetic mouse preimplantation embryos were cultured in vitro under 5 and 20% oxygen for 120 h. Zona pellucida drilling by Peizo micromanipulation were performed to resemble the breach by sperm penetration. Firstly, parthenogenetic embryos had similarly high blastocyst developmental efficiency as fertilized embryos, but significantly higher hatch ratio than fertilized embryos in both O 2 concentrations. 5% O 2 reduced the hatch rate of fertilized embryos from 58.2 to 23.8%, but increased that of parthenogenetic embryos from 81.2 to 90.8% significantly. Analogously, 5% O 2 decreased the ratio of Oct4-positive cells in fertilized blastocysts, whereas increased that in parthenogenetic blastocysts. Additionally, 5% O 2 increased the total embryonic cell number in both fertilized and parthegenetic embryos, when compared to 20% O 2 , and the total cell number of fertilized embryos was also higher than that of parthegenetic embryos, despite O 2 concentration. Real-time PCR revealed that the expression of key genes involving in MAPK pathway and superoxide dismutase family might contribute to preimplantation development and consequent blastocyst hatch in vitro. Finally, we showed that fertilized and parthenogenetic embryos have diverse hatch dynamics in vitro, although the zona pellucida integrity is not the main reason for their mechanistic differences. Both parental genetic material and O 2 concentration, as the representative of intrinsic and extrinsic factors respectively, have significant impacts on mouse preimplantation development and subsequent hatch dynamics, probably by regulating the gene expression involving in MAPK pathway and superoxide dismutase family to control embryonic cell proliferation and allocation of ICM cells.

Chronic effects of silver exposure on ion levels, survival, and silver distribution within developing rainbow trout (Oncorhynchus mykiss) embryos.

PubMed

Guadagnolo, C M; Brauner, C J; Wood, C M

2001-03-01

Rainbow trout embryos were chronically exposed to silver (as AgNO3) in moderately hard water (120 mg CaCO3/L, 0.70 mM Cl-, 1.3 mg/L dissolved organic matter. 12.3+/-0.1 degrees C) at nominal concentrations of 0.1, 1, and 10 microg/L (measured = 0.117+/-0.008, 1.22+/-0.16, and 13.51+/-1.58 microg/L, respectively) to investigate the effects on mortality, ionoregulation, and silver uptake and distribution of the embryo. Mortalities in the low concentrations (0.1 and 1.2 microg/L) were not significantly different from controls throughout embryonic development (days 1-32 postfertilization). Mortalities of embryos in the 13.5-microg/L treatment reached 56% by day 32 postfertilization (33% when accounting for control mortality), by which time more than 50% of surviving embryos had hatched. Accumulation of silver in whole embryos of 1.2- and 13.5-microg/L treatments reached the highest concentrations of 0.13 and 0.24 microg/g total silver, respectively, by day 32, but whole embryo silver burden was not correlated with mortality. Silver concentrations in different compartments of the whole embryo (chorion, dissected embryo, and yolk) were greatest just before hatch and were higher in the chorion for all experimental treatments. Up to 85% of total whole embryo silver content was bound to the chorion, which acts as a protective barrier during silver exposure. Whole embryo Na+ concentration in the 13.5-microg/L treatment was significantly reduced relative to controls from days 23 to 32 postfertilization, and levels in the embryo were reduced by 40% at day 32 postfertilization, indicating that silver toxicity in the whole embryo is associated with an ion regulatory disturbance that is similar to the acute effect of AgNO3 in juvenile and adult trout.

Development of ovine embryos in synthetic oviductal fluid containing amino acids at oviductal fluid concentrations.

PubMed

Walker, S K; Hill, J L; Kleemann, D O; Nancarrow, C D

1996-09-01

The effects of supplementing synthetic oviductal fluid (SOF) with amino acids, at oviductal fluid concentrations, on the development of ovine in vitro-matured/in vitro-fertilized embryos was examined in three experiments. In the first, embryo development in SOF, SOF + 2% human serum (HS), SOF + 20% HS, and SOF + BSA, with and without amino acid supplementation, was examined. Development of zygotes to the blastocyst and hatching blastocyst stages was highest in medium containing 20% HS (64.8% and 54.4%, respectively) irrespective of amino acid supplementation. However, supplementation was significantly beneficial in all other media, with up to 42.1% of zygotes developing into hatching blastocysts. In these media, supplementation also significantly increased the mean number of nuclei per newly formed blastocyst (up to a mean of 70.8) and reduced the time during which blastocysts formed. Experiment 2 was an examination of the effect on embryo development of three amino acid preparations (oviduct amino acid concentrations vs. Eagle's Basal Medium (BME) essential + Minimum Essential Medium (MEM) nonessential vs. MEM essential + MEM nonessential concentrations) and the presence or absence of BSA. Both the amino acid and BSA treatments significantly influenced the percentage of zygotes that developed to the hatching blastocyst stage but not to the blastocyst stage. The preferred medium contained amino acids at oviductal fluid concentrations and BSA (54.5% hatching rate). The amino acid treatments did not significantly influence the mean number of nuclei per newly formed blastocyst, but the addition of BSA had a significant effect (70.7 +/- 1.14 vs. 75.7 +/- 1.13). In experiment 3, embryo development to Day 13 was examined after culture in SOF containing amino acids at oviductal fluid concentrations. Embryos were cultured in the presence of either BSA, polyvinyl alcohol (PVA), or no additional supplement and were transferred to recipient ewes on either Day 0 (after in vitro fertilization), 3, or 5. The addition of BSA or PVA had no significant effect, but significantly more embryos developed to Day 13 following transfer on Day 0 (60.0%) than on either Day 3 or 5 (overall 45.4%). It is concluded that SOF containing oviductal fluid concentrations of amino acids 1) facilitates the development of a high percentage (57.5%) of blastocysts, 2) improves embryo morphology compared with that observed in medium containing HS, 3) significantly improves hatching rates compared with those obtained in SOF containing commercially available preparations of amino acids, and 4) produces embryos with relatively high levels of viability to Day 13 of pregnancy.

Abnormal early cleavage events predict early embryo demise: sperm oxidative stress and early abnormal cleavage.

PubMed

Burruel, Victoria; Klooster, Katie; Barker, Christopher M; Pera, Renee Reijo; Meyers, Stuart

2014-10-13

Human embryos resulting from abnormal early cleavage can result in aneuploidy and failure to develop normally to the blastocyst stage. The nature of paternal influence on early embryo development has not been directly demonstrated although many studies have suggested effects from spermatozoal chromatin packaging, DNA damage, centriolar and mitotic spindle integrity, and plasma membrane integrity. The goal of this study was to determine whether early developmental events were affected by oxidative damage to the fertilizing sperm. Survival analysis was used to compare patterns of blastocyst formation based on P2 duration. Kaplan-Meier survival curves demonstrate that relatively few embryos with short (<1 hr) P2 times reached blastocysts, and the two curves diverged beginning on day 4, with nearly all of the embryos with longer P2 times reaching blastocysts by day 6 (p < .01). We determined that duration of the 2nd to 3rd mitoses were sensitive periods in the presence of spermatozoal oxidative stress. Embryos that displayed either too long or too short cytokineses demonstrated an increased failure to reach blastocyst stage and therefore survive for further development. Although paternal-derived gene expression occurs later in development, this study suggests a specific role in early mitosis that is highly influenced by paternal factors.

Estrogen receptor-mediated effects of a xenoestrogen, bisphenol A, on preimplantation mouse embryos.

PubMed

Takai, Y; Tsutsumi, O; Ikezuki, Y; Hiroi, H; Osuga, Y; Momoeda, M; Yano, T; Taketani, Y

2000-04-21

The effects of bisphenol A, a xenoestrogen widely used in industry and dentistry, were studied in early preimplantation mouse embryos. Two-cell mouse embryos were cultured with 100 pM to 100 microM bisphenol A with or without 100 nM tamoxifen and evaluated at 24-h intervals for their development to eight-cell and blastocyst stages. At 72 h, blastocysts were cultured for another 48 h without bisphenol A, and surface areas of trophoblast spread were measured. At 24 h, more embryos exposed to 3 nM bisphenol A than to controls had reached the eight-cell stage. At 48 h, more embryos exposed to 1 nM and 3 nM bisphenol A than to controls had become blastocysts. At 100 microM, bisphenol A decreased frequency of development to blastocysts. Tamoxifen counteracted both stimulatory and inhibitory effects of bisphenol A on blastocyst formation. Although bisphenol A did not alter blastocyst morphology or cell number, early exposure to 100 microM bisphenol A increased subsequent trophoblast areas. These findings suggest that bisphenol A may not only effect early embryonic development via estrogen receptors even at low, environmentally relevant doses, but also exert some late effects on subsequent development of these embryos. Copyright 2000 Academic Press.

RAPID COMMUNICATION: Nerve growth factor influences cleavage rate and embryo development in sheep.

PubMed

Crispo, M; Dos Santos-Neto, P C; Vilariño, M; Mulet, A P; de León, A; Barbeito, L; Menchaca, A

2016-10-01

Recent information about Nerve growth factor (NGF), a protein traditionally associated to the nervous system that regulates survival and maturation of developing neurons, suggests that it may exert action also on different levels in the reproductive system. The aim of this study was to evaluate the effect of NGF added during in vitro oocyte maturation, fertilization or in vitro embryo development in sheep. Nerve growth factor was supplemented to the culture medium at 0, 100, or 1,000 ng/mL, during either in vitro maturation (Exp. 1), in vitro fertilization (Exp. 2), or in vitro culture (Exp. 3). In addition, NGF mRNA expression was determined in cumulus cells and oocytes. Nerve growth factor induced early cleavage when added during oocyte maturation or fertilization, improved embryo development when added during fertilization, and had no significant effect when added during embryo culture. In general, the effect was more evident with 100 rather than 1,000 ng/mL (P < 0.05). Expression of endogenous NGF was not detected in oocytes, and increased in cumulus cells when 1,000 ng/mL of NGF was added during fertilization, but not during maturation and embryo culture. In conclusion, the addition of NGF during oocyte maturation and fertilization affects in vitro cleavage and embryo development in sheep. We suggest a possible effect of this growth factor on oocyte maturation and mainly on the fertilization process.

A novel embryo culture media supplement that improves pregnancy rates in mice.

PubMed

Highet, A R; Bianco-Miotto, T; Pringle, K G; Peura, A; Bent, S; Zhang, J; Nottle, M B; Thompson, J G; Roberts, C T

2017-03-01

The preimplantation embryo in vivo is exposed to numerous growth factors in the female reproductive tract, which are not recapitulated in embryo culture media in vitro The IGF2 and plasminogen activator systems facilitate blastocyst development. We hypothesized that the addition of IGF2 in combination with urokinase plasminogen activator (uPA) and plasminogen could improve rates of blastocyst hatching and implantation in mice. B6BcF1 and CBAB6F2 mouse embryos were divided into one of four supplemented culture media treatment groups: (1) control (media only); (2) 12.5 nM IGF2; (3) 10 µg/mL uPA and 5 µg/mL plasminogen; or (4) a combination of IGF2, uPA and plasminogen treatments. Embryo development to blastocyst stage and hatching were assessed before transfer to pseudopregnant recipient females and implantation, pregnancy rates and postnatal growth were assessed. After 90.5 h of culture, IGF2 + U + P treatment increased the percentage of B6BcF1 embryos that were hatching/hatched and percentage developing to blastocyst stage compared with controls (P < 0.02). Following B6BcF1 embryo transfer, IGF2 + U + P treatment increased implantation sites at day 8 of pregnancy compared with controls (P < 0.05). Replication in the CBAB6F2 mouse strain showed significant improvements in pregnancy rates at days 8 and 18 but not in blastocyst development. No adverse effects were seen on gestational age, litter size or birthweight, or the reproductive capacity of offspring of IGF2 + U + P treated embryos. For embryos susceptible to detrimental effects of in vitro culture, IGF2, uPA and plasminogen supplementation of culture media can improve pregnancy success, but the effect of treatment is dependent on the mouse strain. © 2017 Society for Reproduction and Fertility.

Near-infrared laser irradiation improves the development of mouse pre-implantation embryos.

PubMed

Yokoo, Masaki; Mori, Miho

2017-05-27

The aim of the present study was to assess the effects of near-infrared laser irradiation on the in vitro development of mouse embryos. Female ICR mice were superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin (hCG), and mated with male mice. Two-cell stage embryos were collected 40 h after administering hCG and cultured in M16 medium. Two-cell embryos (0 h after culture), 8-cell embryos (approx. 30 h after culture), morula (approx. 48 h after culture), and blastocysts (approx. 73 h after culture) were irradiated at 904 nm for 60 s. These embryos were cultured in a time-lapse monitoring system and the timing of blastocyst hatching was evaluated. Some of the irradiated blastocysts were transferred to the uterine horns of pseudopregnant recipients immediately after irradiation. Pregnancy rates, and offspring growth and fertility, were evaluated. Near-infrared laser irradiation increased the speed of in vitro mouse embryo development. In irradiated blastocysts, hatching was faster than in control (non-irradiated) blastocysts (18.4 vs. 28.2 h, P < 0.05). When 195 irradiated blastocysts were transferred to 18 pseudopregnant mice, all became pregnant and 92 (47.2%) normal-looking pups were born alive. When 182 control blastocysts were transferred to 17 pseudopregnant mice, 14 (82.4%) became pregnant and 54 (29.7%) normal-looking pups were born alive. The growth trajectories (up to 5 weeks) of offspring from irradiated blastocysts were similar to those from control blastocysts. Second generation offspring from transplanted animals were all fertile. These results indicate that near-infrared laser irradiation improves the quality of mouse embryo development in vitro, and increases the live birth rate without affecting the normality of the offspring. Thus, the near-infrared laser method may enhance the quality of embryos and contribute to improvements in reproductive technologies in mammals. Copyright © 2017 Elsevier Inc. All rights reserved.

Time-lapse microscopy and image analysis in basic and clinical embryo development research.

PubMed

Wong, C; Chen, A A; Behr, B; Shen, S

2013-02-01

Mammalian preimplantation embryo development is a complex process in which the exact timing and sequence of events are as essential as the accurate execution of the events themselves. Time-lapse microscopy (TLM) is an ideal tool to study this process since the ability to capture images over time provides a combination of morphological, dynamic and quantitative information about developmental events. Here, we systematically review the application of TLM in basic and clinical embryo research. We identified all relevant preimplantation embryo TLM studies published in English up to May 2012 using PubMed and Google Scholar. We then analysed the technical challenges involved in embryo TLM studies and how these challenges may be overcome with technological innovations. Finally, we reviewed the different types of TLM embryo studies, with a special focus on how TLM can benefit clinical assisted reproduction. Although new parameters predictive of embryo development potential may be discovered and used clinically to potentially increase the success rate of IVF, adopting TLM to routine clinical practice will require innovations in both optics and image analysis. Combined with such innovations, TLM may provide embryologists and clinicians with an important tool for making critical decisions in assisted reproduction. In this review, we perform a literature search of all published early embryo development studies that used time-lapse microscopy (TLM). From the literature, we discuss the benefits of TLM over traditional time-point analysis, as well as the technical difficulties and solutions involved in implementing TLM for embryo studies. We further discuss research that has successfully derived non-invasive markers that may increase the success rate of assisted reproductive technologies, primarily IVF. Most notably, we extend our discussion to highlight important considerations for the practical use of TLM in research and clinical settings. Copyright © 2012 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Treatment of porcine donor cells and reconstructed embryos with the antioxidant melatonin enhances cloning efficiency.

PubMed

Pang, Yun-Wei; An, Lei; Wang, Peng; Yu, Yong; Yin, Qiu-Dan; Wang, Xiao-Hong; Xin-Zhang; Qian-Zhang; Yang, Mei-Ling; Min-Guo; Wu, Zhong-Hong; Tian, Jian-Hui

2013-05-01

This study was conducted to investigate the effect of melatonin during the culture of donor cells and cloned embryos on the in vitro developmental competence and quality of cloned porcine embryos. At concentrations of 10(-6 )M or 10(-8) M, melatonin significantly enhanced the proliferation of porcine fetal fibroblasts (PFFs), and the blastocyst rate was significantly increased in the 10(-10) M melatonin-treated donor cell group. Cloned embryo development was also improved in embryo culture medium that was supplemented with 10(-9) M or 10(-12) M melatonin. When both donor cells and cloned embryos were treated with melatonin, the cleavage rate and total cell number of blastocysts were not significantly affected; however, the blastocyst rate was increased significantly (20.0% versus 11.7%). TUNEL assays showed that combined melatonin treatment reduced the rate of apoptotic nuclei (3.6% versus 6.1%). Gene expression analysis of the apoptosis-related genes BAX, BCL2L1, and p53 showed that the expression of BCL2L1 was significantly elevated 2.7-fold relative to the control group, while the expression of BAX and p53 was significantly decreased by 3.7-fold and 23.2-fold, respectively. In addition, we detected the expression of two melatonin receptors (MT1 and MT2) in PFFs but not in porcine cloned embryos. We conclude that exogenous melatonin enhances the development of porcine cloned embryos and improves embryo quality by inhibiting p53-mediated apoptotic pathway. The proliferation of PFFs may be mediated by receptor binding, but the beneficial effects of melatonin on embryonic development may be receptor-independent, possibly through melatonin's ability to directly scavenge free radicals. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Hematology from embryo to adult in the bobwhite quail (Colinus virginianus): Differential effects in the adult of clutch, sex and hypoxic incubation.

PubMed

Flores-Santin, Josele; Rojas Antich, Maria; Tazawa, Hiroshi; Burggren, Warren W

2018-04-01

Hematology and its regulation in developing birds have been primarily investigated in response to relatively short-term environmental challenges in the embryo. Yet, whether any changes induced in the embryo persist into adulthood as a hematological form of "fetal programming" is unknown. We hypothesized that: 1) chronic as opposed to acute hypoxic incubation will alter hematological respiratory variables in embryos of bobwhite quail (Colinus virginianus), and 2) alterations first appearing in the embryo will persist into hatchlings through into adulthood. To test these hypotheses, we first developed an embryo-to-adult profile of normal hematological development by measuring hematocrit (Hct), red blood cell concentration ([RBC]), hemoglobin concentration ([Hb]), mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration, as well plasma osmolality. Hct, [RBC] and [Hb] in normoxic-incubated birds (controls) steadily increased from ~22%, ~1.6 × 10 6  μL -1 and ~7 g% in day 12 embryos to almost double the values at maturity in adult birds. Both cohort and sex affected hematology of normoxic-incubated birds. A second population, incubated from day 0 (d0) in 15% O 2 , surprisingly revealed little or no significant difference from controls in hematology in embryos. In hatchlings and adults, hypoxic incubation caused no significant modification to any variables. Compared to major hematological effects caused by hypoxic incubation in chickens, the hematology of the bobwhite quail embryo appears to be minimally affected by hypoxic incubation, with very few effects induced during hypoxic incubation actually persisting into adulthood. Copyright © 2018 Elsevier Inc. All rights reserved.

Accumulation of long-lived mRNAs associated with germination in embryos during seed development of rice

PubMed Central

Sano, Naoto; Ono, Hanako; Murata, Kazumasa; Yamada, Tetsuya; Hirasawa, Tadashi; Kanekatsu, Motoki

2015-01-01

Mature dry seeds contain translatable mRNAs called long-lived mRNAs. Early studies have shown that protein synthesis during the initial phase of seed germination occurs from long-lived mRNAs, without de novo transcription. However, the gene expression systems that generate long-lived mRNAs in seeds are not well understood. To examine the accumulation of long-lived mRNAs in developing rice embryos, germination tests using the transcriptional inhibitor actinomycin D (Act D) were performed with the Japonica rice cultivar Nipponbare. Although over 70% of embryos at 10 days after flowering (DAF) germinated in the absence of the inhibitor, germination was remarkably impaired in embryos treated with Act D. In contrast, more than 70% of embryos at 20, 25, 30 and 40 DAF germinated in the presence of Act D. The same results were obtained when another cultivar, Koshihikari, was used, indicating that the long-lived mRNAs required for germination predominantly accumulate in embryos between 10 and 20 DAF during seed development. RNA-Seq identified 529 long-lived mRNA candidates, encoding proteins such as ABA, calcium ion and phospholipid signalling-related proteins, and HSP DNA J, increased from 10 to 20 DAF and were highly abundant in 40 DAF embryos of Nipponbare and Koshihikari. We also revealed that these long-lived mRNA candidates are clearly up-regulated in 10 DAF germinating embryos after imbibition, suggesting that the accumulation of these mRNAs in embryos is indispensable for the induction of germination. The findings presented here may facilitate in overcoming irregular seed germination or producing more vigorous seedlings. PMID:25941326

Atrial and ventricular septal changes in ethanol vapour exposed chick embryos.

PubMed

Kamran, Kiran; Khan, Muhammad Yunus; Minhas, Liaqat Ali

2015-03-01

To study the effects of ethanol vapour exposure on development of atrial and ventricular septa of chick embryo. The experimental study was conducted at the College of Physicians and Surgeons, Islamabad, from 2006 to 2007. The experimental and control groups were further divided into three subgroups based on the day of sacrifice. The experimental group was exposed to ethanol vapours produced in a specially-designed vapour chamber and then compared with age-matched controls. There were 90 eggs in each of the two groups. The development of inter-ventricular septum completed at day 7 of development in chick embryo. Ethanol vapour exposure produced a small discontinuity at day 10 of development in a chick embryo which may be labelled as ventricular septal defect since ventricular development is completed by day 7. Interatrial septum formed till day 7 with small perforations which persisted till hatching. Ethanol vapour exposure may lead to ventricular septal defect.

Stage specific effects of soluble copper and copper oxide nanoparticles during sea urchin embryo development and their relation to intracellular copper uptake.

PubMed

Torres-Duarte, Cristina; Ramos-Torres, Karla M; Rahimoff, René; Cherr, Gary N

2017-08-01

The effects of exposure to either soluble copper (copper sulfate) or copper oxide nanoparticles (nano-CuO) during specific early developmental stages of sea urchin embryos were analyzed. Soluble copper caused significant malformations in embryos (skeletal malformations, delayed development or gut malformations) when present at any given stage, while cleavage stage was the most sensitive to nano-CuO exposure causing skeletal malformations and decreased total antioxidant capacity. The stage specificity was linked to higher endocytic activity during the first hours of development that leads to higher accumulation of copper in specific cells critical for development. Results indicate that nano-CuO results in higher accumulation of copper inside of embryos and this intracellular copper is more persistent as compared to soluble copper. The possible implications later in development are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Coast Guard : update on Marine Information for Safety and Law Enforcement System

DOT National Transportation Integrated Search

2001-10-01

The Coast Guard is developing a web-based information system to replace an aging computer system that it uses to track safety and law-enforcement actions involving commercial and recreational vessels. In 1995 the Coast Guard awarded a contract to dev...

Linking embryo toxicity with genotoxic responses in the freshwater snail Physa acuta: single exposure to benzo(a)pyrene, fluoxetine, bisphenol A, vinclozolin and exposure to binary mixtures with benzo(a)pyrene.

PubMed

Sánchez-Argüello, Paloma; Aparicio, Natalia; Fernández, Carlos

2012-06-01

Genotoxic effects on fauna after waterborne pollutant exposure have been demonstrated by numerous research programmes. Less effort has been focused on establishing relationship between genotoxicity and long-term responses at higher levels of biological organization. Taking into account that embryos may be more sensitive indicators of reproductive impairment than alterations in fertility, we have developed two assays in multiwell plates to address correlations between embryo toxicity and genotoxicity. The potential teratogenicity was assessed by analyzing abnormal development and mortality of Physa acuta at embryonic stage. Genotoxicity was measured by the micronucleus (MN) test using embryonic cells. Our results showed that linkage between genotoxicity and embryo toxicity depends on mechanisms of action of compounds under study. Embryo toxic responses showed a clear dose-related tendency whereas no clear dose-dependent effect was observed in micronucleus induction. The higher embryo toxicity was produced by benzo(a)pyrene exposure followed by fluoxetine and bisphenol A. Vinclozolin was the lower embryo toxic compound. Binary mixtures with BaP always resulted in higher embryo toxicity than single exposures but antagonistic effects were observed for MN induction. Benzo(a)pyrene produced the higher MN induction at 0.04 mg/L, which also produced clear embryo toxic effects. Fluoxetine did not induce cytogenetic effects but 0.25mg/L altered embryonic development. Bisphenol A significantly reduced hatchability at 0.5mg/L while MN induction appeared with higher treatments than those that start causing teratogenicity. Much higher concentration of vinclozolin (5mg/L) reduced hatchability and induced maximum MN formation. In conclusion, while validating one biomarker of genotoxicity and employing one ecologically relevant effect, we have evaluated the relative sensitivity of a freshwater mollusc for a range of chemicals. The embryo toxicity test is a starting point for the development of a life cycle test with freshwater snails even for undertaking multigeneration studies focused on transgenerational effects. Copyright © 2012 Elsevier Inc. All rights reserved.

Determination of escin content in androgenic embryos and hairy root culture of Aesculus hippocastanum.

PubMed

Calić-Dragosavac, Dusica; Zdravković-Korać, Snezana; Savikin-Fodulović, Katarina; Radojević, Ljiljana; Vinterhalter, Branka

2010-05-01

Escin, a group of chemically related triterpenic glycosides, is widely used in commercial preparations for the treatment of venous insufficiency. Since the zygotic embryo cotyledons accumulate the highest amount of escin, it is currently extracted from the seeds of horse chestnut, Aesculus hippocastanum L. (Hippocastanaceae), on a large scale. As this material is available during only short period of the year, we studied the possibility of using plant tissue culture to obtain escin. For this purpose, the content of escin in androgenic embryos and hairy root cultures of horse chestnut was studied. Escin content was found to be dependent on the stage of androgenic embryo development and the type of phytoregulator supplemented to the nutritive medium. In the absence of phytoregulators, androgenic embryos at the globular stage of development contained approximately four times less escin than those at the cotyledonary stage. Inclusion of various phytoregulators in the nutritive media stimulated escin production. Among them, 2,4-dichlorophenoxyacetic acid (2,4-D) showed the most pronounced effect, with escin content almost reaching that found in zygotic embryos (6.77% versus 6.96%). Two hairy root clones produced substantial amounts of escin (3.57% and 4.09%), less than zygotic embryos, but higher than cotyledonary embryos on phytoregulator-free medium.

Nepro is localized in the nucleolus and essential for preimplantation development in mice.

PubMed

Hashimoto, Masakazu; Sato, Tatsuya; Muroyama, Yuko; Fujimura, Lisa; Hatano, Masahiko; Saito, Tetsuichiro

2015-09-01

We generated knockout (KO) mice of Nepro, which has been shown to be necessary to maintain neural progenitor cells downstream of Notch in the mouse developing neocortex by using knockdown experiments, to explore its function in embryogenesis. Nepro KO embryos were morphologically indistinguishable from wild type (WT) embryos until the morula stage but failed in blastocyst formation, and many cells of the KO embryos resulted in apoptosis. We found that Nepro was localized in the nucleolus at the blastocyst stage. The number of nucleolus precursor bodies (NPBs) and nucleoli per nucleus was significantly higher in Nepro KO embryos compared with WT embryos later than the 2-cell stage. Furthermore, at the morula stage, whereas 18S rRNA and ribosomal protein S6 (rpS6), which are components of the ribosome, were distributed to the cytoplasm in WT embryos, they were mainly localized in the nucleoli in Nepro KO embryos. In addition, in Nepro KO embryos, the amount of the mitochondria-associated p53 protein increased, and Cytochrome c was distributed in the cytoplasm. These findings indicate that Nepro is a nucleolus-associated protein, and its loss leads to the apoptosis before blastocyst formation in mice. © 2015 Japanese Society of Developmental Biologists.

Where does New Zealand stand on permitting research on human embryos?

PubMed

Jones, D Gareth

2014-08-01

In many respects New Zealand has responded to the assisted reproductive technologies (ARTs) as positively as many comparable societies, such as Australia and the UK. Consequently, in vitro fertilisation (IVF) and pre-implantation genetic diagnosis (PGD) are widely available, as is non-commercial surrogacy utilising IVF. These developments have been made possible by the Human Assisted Reproductive Technology (HART) Act 2004, overseen by its two committees, the Advisory Committee on Assisted Reproductive Technology (ACART) and the Ethics Committee (ECART). However, New Zealand stands apart from many of these other societies by the lack of permission for scientists to conduct research using human embryos. There is no doubt this reflects strongly held viewpoints on the part of some that embryos should be protected and not exploited. Legitimate as this stance is, the resulting situation is problematic when IVF is already designated as an established procedure. This is because the development of IVF involved embryo research, and continuing improvements in procedures depend upon ongoing embryo research. While prohibition of research on human embryos gives the impression of protecting embryos, it fails to do this and also fails to enhance the health and wellbeing of children born using IVF. This situation will not be rectified until research is allowed on human embryos.

Mortality, size of the gonads, and ultrastructure of primordial germ cell in chick embryos treated with gamma-irradiation or injected with donor cells.

PubMed

Maeda, T; Clark, M E; Etches, R J

1998-06-01

The effects of injection and/or gamma-irradiation prior to injection on mortality, size of the gonads, and ultrastructure of primordial germ cell (PGC) were examined after 5 d of incubation. The mortality of embryos injected with donor cells was significantly higher than that of control and irradiated embryos. All irradiated embryos were alive, although their development was delayed compared to those not exposed to irradiation. The size of the gonads of embryos injected with donor cells were similar to those of control embryos, however, the size of the gonads in irradiated embryos was significantly smaller than those of control embryos. The number of PGC in the gonads was significantly decreased by irradiation. There was no notable effect of irradiation or injection on the nuclei and cytoplasmic organelles in PGC.

The Virtual Embryo Project (v-Embryo™)

EPA Science Inventory

The v-Embryo is a far reaching new research program at the US EPA to develop a working computer model of a mammalian embryo that can be used to better understand the prenatal risks posed by environmental chemicals and to eventually predict a chemical's potential developmental tox...

Optimizing the number of embryos to transfer on day 5: two should be the limit.

PubMed

Ruhlmann, Claudio; Molina, Lucas; Tessari, Graciano; Ruhlmann, Felicitas; Tessari, Lautaro; Gnocchi, Diego; Cattaneo, Antonio; Irigoyen, Marcela; Martínez, Alejandro Gustavo

2017-02-01

To define the appropriate number of embryos to be transferred at day 5. Retrospective analysis of 784 consecutive fresh day-5 embryo transfers performed between 2007 and 2015, divided in three groups: Group A (N = 219): received the only 2 embryos that reached a transferable stage; Group B (N = 357): received 2 selected embryos among several that reached a transferable stage; Group C (N = 208): received the only 3 developing embryos. Clinical pregnancy, implantation, multiple pregnancy and delivery rates were registered. Kruskal-Wallis and Fisher Exact tests were applied as appropriate. Age and previous attempts were comparable in the 3 groups. Compared with Group A, Groups B and C had a higher oocyte recovery (10.7 ± 5.6 vs. 14.7 ± 8.0 vs. 13.8 ± 6.6), fertilization rate (75.97% vs. 81.60% vs. 83.29%) and percentage of embryos reaching a transferable stage on day 5 (39.98% vs. 63.99% vs. 60.97%), as well as a significantly higher clinical pregnancy (42.92% vs. 61.06% vs. 58.17%) and implantation rates (21.09% vs. 40.98% vs. 36.97%). The multiple pregnancy rate was higher in Groups B and C than in Group A (11.70% vs. 31.19% vs. 37.19%). The high order multiple pregnancy rate (> 2) was significantly increased in group C (1.06% vs. 0.92% vs. 14.05%). In patients with 3 or more day 5 developing embryos, delivery rates are similar if 2 or 3 embryos are transferred. The transfer of 3 embryos carries an unacceptable increase in the risk of high order multiple pregnancy, with its known consequences. According to our data, we should not exceed the number of 2 day-5 fresh embryos transferred.

Optimizing the number of embryos to transfer on day 5: two should be the limit

PubMed Central

Ruhlmann, Claudio; Molina, Lucas; Tessari, Graciano; Ruhlmann, Felicitas; Tessari, Lautaro; Gnocchi, Diego; Cattaneo, Antonio; Irigoyen, Marcela; Martínez, Alejandro Gustavo

2017-01-01

Objective To define the appropriate number of embryos to be transferred at day 5. Methods Retrospective analysis of 784 consecutive fresh day-5 embryo transfers performed between 2007 and 2015, divided in three groups: Group A (N = 219): received the only 2 embryos that reached a transferable stage; Group B (N = 357): received 2 selected embryos among several that reached a transferable stage; Group C (N = 208): received the only 3 developing embryos. Clinical pregnancy, implantation, multiple pregnancy and delivery rates were registered. Kruskal-Wallis and Fisher Exact tests were applied as appropriate. Results Age and previous attempts were comparable in the 3 groups. Compared with Group A, Groups B and C had a higher oocyte recovery (10.7 ± 5.6 vs. 14.7 ± 8.0 vs. 13.8 ± 6.6), fertilization rate (75.97% vs. 81.60% vs. 83.29%) and percentage of embryos reaching a transferable stage on day 5 (39.98% vs. 63.99% vs. 60.97%), as well as a significantly higher clinical pregnancy (42.92% vs. 61.06% vs. 58.17%) and implantation rates (21.09% vs. 40.98% vs. 36.97%). The multiple pregnancy rate was higher in Groups B and C than in Group A (11.70% vs. 31.19% vs. 37.19%). The high order multiple pregnancy rate (> 2) was significantly increased in group C (1.06% vs. 0.92% vs. 14.05%). Conclusions In patients with 3 or more day 5 developing embryos, delivery rates are similar if 2 or 3 embryos are transferred. The transfer of 3 embryos carries an unacceptable increase in the risk of high order multiple pregnancy, with its known consequences. According to our data, we should not exceed the number of 2 day-5 fresh embryos transferred. PMID:28333024

Production and manipulation of bovine embryos: techniques and terminology.

PubMed

Machaty, Z; Peippo, J; Peter, A

2012-09-15

There are numerous publications regarding bovine embryos, ranging from descriptions of their appearance and development to emerging techniques in the field of assisted reproductive technology. Concurrently, several specialized terms have been developed to describe the bovine embryo. The purpose of the current review is two-fold; it is primarily to describe techniques involved in the in vivo and in vitro production of bovine embryos and their manipulation, and secondarily to summarize specialized terms used in these processes. The intention is not to review these techniques in detail, but instead to provide salient points and current knowledge regarding these techniques, with a focus on terminology. The first review dealt with classical and contemporary terminology used to describe morphologic aspects of ovarian dynamics in cattle. Subsequently, the terms and current understanding of processes involved in preattachment bovine embryos were described in the second review. As the third article in a series, this mini-review is focused on defining the production, manipulation, and transfer of bovine preattachment embryos. Copyright © 2012 Elsevier Inc. All rights reserved.

Toxicity assessment and bioaccumulation in zebrafish embryos exposed to carbon nanotubes suspended in Pluronic® F-108.

PubMed

Wang, Ruhung; N Meredith, Alicea; Lee, Michael; Deutsch, Dakota; Miadzvedskaya, Lizaveta; Braun, Elizabeth; Pantano, Paul; Harper, Stacey; Draper, Rockford

2016-08-01

Carbon nanotubes (CNTs) are often suspended in Pluronic® surfactants by sonication, which may confound toxicity studies because sonication of surfactants can create degradation products that are toxic to mammalian cells. Here, we present a toxicity assessment of Pluronic® F-108 with and without suspended CNTs using embryonic zebrafish as an in vivo model. Pluronic® sonolytic degradation products were toxic to zebrafish embryos just as they were to mammalian cells. When the toxic Pluronic® fragments were removed, there was little effect of pristine multi-walled CNTs (pMWNTs), carboxylated MWNTs (cMWNTs) or pristine single-walled carbon nanotubes (pSWNTs) on embryo viability and development, even at high concentrations. A gel electrophoretic method coupled with Raman imaging was developed to measure the bioaccumulation of CNTs by zebrafish embryos, and dose-dependent uptake of CNTs was observed. These data indicate that embryos accumulate pMWNTs, cMWNTs and pSWNTs yet there is very little embryo toxicity.

Toxicity assessment and bioaccumulation in zebrafish embryos exposed to carbon nanotubes suspended in Pluronic® F-108

PubMed Central

Wang, Ruhung; Meredith, Alicea N.; Lee, Michael; Deutsch, Dakota; Miadzvedskaya, Lizaveta; Braun, Elizabeth; Pantano, Paul; Harper, Stacey; Draper, Rockford

2015-01-01

Carbon nanotubes (CNTs) are often suspended in Pluronic® surfactants by sonication, which may confound toxicity studies because sonication of surfactants can create degradation products that are toxic to mammalian cells. Here, we present a toxicity assessment of Pluronic® F-108 with and without suspended CNTs using embryonic zebrafish as an in vivo model. Pluronic® sonolytic degradation products were toxic to zebrafish embryos just as they were to mammalian cells. When the toxic Pluronic® fragments were removed, there was little effect of pristine multi-walled CNTs (pMWNTs), carboxylated MWNTs (cMWNTs) or pristine single-walled carbon nanotubes (pSWNTs) on embryo viability and development, even at high concentrations. A gel electrophoretic method coupled with Raman imaging was developed to measure the bioaccumulation of CNTs by zebrafish embryos, and dose-dependent uptake of CNTs was observed. These data indicate that embryos accumulate pMWNTs, cMWNTs and pSWNTs yet there is very little embryo toxicity. PMID:26559437

OpenSource lab-on-a-chip physiometer for accelerated zebrafish embryo biotests.

PubMed

Akagi, Jin; Hall, Chris J; Crosier, Kathryn E; Cooper, Jonathan M; Crosier, Philip S; Wlodkowic, Donald

2014-01-02

Zebrafish (Danio rerio) embryo assays have recently come into the spotlight as convenient experimental models in both biomedicine and ecotoxicology. As a small aquatic model organism, zebrafish embryo assays allow for rapid physiological, embryo-, and genotoxic tests of drugs and environmental toxins that can be simply dissolved in water. This protocol describes prototyping and application of an innovative, miniaturized, and polymeric chip-based device capable of immobilizing a large number of living fish embryos for real-time and/or time-lapse microscopic examination. The device provides a physical address designation to each embryo during analysis, continuous perfusion of medium, and post-analysis specimen recovery. Miniaturized embryo array is a new concept of immobilization and real-time drug perfusion of multiple individual and developing zebrafish embryos inside the mesofluidic device. The OpenSource device presented in this protocol is particularly suitable to perform accelerated fish embryo biotests in ecotoxicology and phenotype-based pharmaceutical screening. Copyright © 2014 John Wiley & Sons, Inc.

ZINC INFLUENCES THE IN VITRO DEVELOPMENT OF PERI-IMPLANTATION MOUSE EMBRYOS

EPA Science Inventory

Background: For humans, it is estimated that over 70% of concepti are lost during early development. In culture, mouse peri-implantation embryos can mimic development from the blastocyst to the egg cylinder stage of development, a period during which implantation occurs in viv...

Successful development of viable blastocysts from enhanced green fluorescent protein transgene-microinjected mouse embryos: comparison of culture media.

PubMed

Devgan, Vikram; Seshagiri, Polani B

2003-07-01

To improve efficiency of transgenesis, we compared M16 and CZB embryo culture media, supporting development to blastocysts of FVB/N mouse pronuclear-eggs, microinjected with enhanced green fluorescent protein (EGFP) transgene. When EGFP-injected-eggs were cultured (120 hr), blastocyst development was significantly (P < 0.03) higher in M16 medium (72.5 +/- 2.4%) than that in CZB (13.2 +/- 4.3%) or CZBG (CZB with 5.6 mM glucose at 48 hr culture) (62.1 +/- 3.7%) media. Blastocyst development of noninjected embryos was higher in M16 (92.0 +/- 2.6%) and CZBG (83.9 +/- 3.9%) media than in CZB (31.9 +/- 2.8%) medium (P < 0.0001). However, percentages of morulae at 72 hr were comparable in all treatments. Developed blastocysts were better in M16 than in CZB or CZBG media. Consistent with this, mean cell number per blastocyst, developed from injected embryos, was significantly (P < 0.002) higher in M16 medium (79.6), than those in CZB (31.3) or CZBG media (60.7); similar with noninjected embryos. Cell allocation to trophectoderm (TE) and inner cell mass (ICM), i.e., TE:ICM ratio, for injected blastocysts in M16 (3.0) was less than (P < 0.05) those in CZB (4.2) and CZBG (4.4) media; similar with noninjected blastocysts. Moreover, blastocysts, developed in M16 and CZBG media, hatched, attached, and exhibited trophoblast outgrowth; 18% of them showed EGFP-expression. Importantly, blastocysts from M16 medium produced live transgenic "green" pups (11%) following embryo transfer. Taken together, our results indicate that supplementation of glucose, at 48 hr of culture (CZBG), is required for morula to blastocyst transition; M16 medium, containing glucose from the beginning of culture, is superior to CZB or CZBG for supporting development of biologically viable blastocysts from EGFP-transgene-injected mouse embryos. Copyright 2003 Wiley-Liss, Inc.

Factors Affecting the Development of Somatic Cell Nuclear Transfer Embryos in Cattle

PubMed Central

AKAGI, Satoshi; MATSUKAWA, Kazutsugu; TAKAHASHI, Seiya

2014-01-01

Nuclear transfer is a complex multistep procedure that includes oocyte maturation, cell cycle synchronization of donor cells, enucleation, cell fusion, oocyte activation and embryo culture. Therefore, many factors are believed to contribute to the success of embryo development following nuclear transfer. Numerous attempts to improve cloning efficiency have been conducted since the birth of the first sheep by somatic cell nuclear transfer. However, the efficiency of somatic cell cloning has remained low, and applications have been limited. In this review, we discuss some of the factors that affect the developmental ability of somatic cell nuclear transfer embryos in cattle. PMID:25341701

Stickleback embryos use ATP-binding cassette transporters as a buffer against exposure to maternally derived cortisol

PubMed Central

Bukhari, Syed Abbas; Bell, Alison M.

2016-01-01

Offspring from females that experience stressful conditions during reproduction often exhibit altered phenotypes and many of these effects are thought to arise owing to increased exposure to maternal glucocorticoids. While embryos of placental vertebrates are known to regulate exposure to maternal glucocorticoids via placental steroid metabolism, much less is known about how and whether egg-laying vertebrates can control their steroid environment during embryonic development. We tested the hypothesis that threespine stickleback (Gasterosteus aculeatus) embryos can regulate exposure to maternal steroids via active efflux of maternal steroids from the egg. Embryos rapidly (within 72 h) cleared intact steroids, but blocking ATP-binding cassette (ABC) transporters inhibited cortisol clearance. Remarkably, this efflux of cortisol was sufficient to prevent a transcriptional response of embryos to exogenous cortisol. Taken together, these findings suggest that, much like their placental counterparts, developing fish embryos can actively regulate their exposure to maternal cortisol. These findings highlight the fact that even in egg-laying vertebrates, the realized exposure to maternal steroids is mediated by both maternal and embryonic processes and this has important implications for understanding how maternal stress influences offspring development. PMID:26984623

Metabolome analysis of Drosophila melanogaster during embryogenesis.

PubMed

An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

2014-01-01

The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos' metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo.

NtKRP, a kinesin-12 protein, regulates embryo/seed size and seed germination via involving in cell cycle progression at the G2/M transition.

PubMed

Tian, Shujuan; Wu, Jingjing; Li, Fen; Zou, Jianwei; Liu, Yuwen; Zhou, Bing; Bai, Yang; Sun, Meng-Xiang

2016-10-25

Kinesins comprise a superfamily of microtubule-based motor proteins involved in essential processes in plant development, but few kinesins have been functionally identified during seed development. Especially, few kinesins that regulate cell division during embryogenesis have been identified. Here we report the functional characterization of NtKRP, a motor protein of the kinesin-12 family. NtKRP is predominantly expressed in embryos and embryonic roots. NtKRP RNAi lines displayed reductions in cell numbers in the meristematic zone, in embryonic root length, and in mature embryo and seed sizes. Furthermore, we also show that CDKA;1 binds to NtKRP at the consensus phosphorylation sites and that the decreased cell numbers in NtKRP-silenced embryos are due to a delay in cell division cycle at the G2/M transition. In addition, binding between the cargo-binding tail domain of NtKRP and CDKA; 1 was also determined. Our results reveal a novel molecular pathway that regulates embryo/seed development and critical role of kinesin in temporal and spatial regulation of a specific issue of embryo developmental.

Kinetics of fertilization and development, and sex ratio of bovine embryos produced using the semen of different bulls.

PubMed

Alomar, M; Tasiaux, H; Remacle, S; George, F; Paul, D; Donnay, I

2008-08-01

The between bulls variation in in vitro fertility and the shift of sex ratio towards male embryos are two problems affecting the in vitro production (IVP) of bovine embryos. Our objective was to evaluate the kinetics of fertilization, embryo development and the sex ratio of the resulting embryos using the frozen/thawed semen of four different bulls. In a first experiment, the kinetics of pronucleus (PN) formation was evaluated at 8, 12 and 18 h post-insemination (hpi). Based upon the pronuclei sizes and the distance between the two pronuclei, inseminated oocytes were classified in three PN stages. Differences between bulls were observed at each time point, but were more important at 12 hpi. At 8 and 12 hpi bull III showed a significantly faster PN evolution by comparison with the three other bulls (P<0.05), while at 18 hpi, the proportion of the three PN stages was similar to those of bulls I and IV, bull II being delayed. In a second experiment, the kinetics of in vitro embryo development was compared using time-lapse cinematography. The analysis of embryos reaching the blastocyst stage revealed significant differences in the mean time of first cleavage (range of 22.7-25.6h, P<0.05), while the lengths of the subsequent three cell cycles did not differ between bulls. The early mean time of first cleavage with bull III was associated with an early blastulation and a high blastocyst rate at Day 7, in opposition to what was observed with bull II showing a later timing of first cleavage (first cleavage 22.1 hpi versus 25.5 hpi; blastulation 140.4 hpi versus 152.5 hpi; D7 blastocyst rates: 31.3% versus 21.9%; P<0.05). In a third experiment, 65-76 Day 8 blastocysts per bull were sexed by PCR. Only blastocysts obtained with bull III showed a shift in sex ratio towards male embryos (76% male embryos; P<0.05). Such shift was already observed at the 2-cell and morula stages. In conclusion, the bull influences the kinetics of PN formation, of embryo development and the sex ratio of the embryos. Moreover, those parameters might be related.

Genome-wide DNA methylation patterns of bovine blastocysts derived from in vivo embryos subjected to in vitro culture before, during or after embryonic genome activation.

PubMed

Salilew-Wondim, Dessie; Saeed-Zidane, Mohammed; Hoelker, Michael; Gebremedhn, Samuel; Poirier, Mikhaël; Pandey, Hari Om; Tholen, Ernst; Neuhoff, Christiane; Held, Eva; Besenfelder, Urban; Havlicek, Vita; Rings, Franca; Fournier, Eric; Gagné, Dominic; Sirard, Marc-André; Robert, Claude; Gad, Ahmed; Schellander, Karl; Tesfaye, Dawit

2018-06-01

Aberrant DNA methylation patterns of genes required for development are common in in vitro produced embryos. In this regard, we previously identified altered DNA methylation patterns of in vivo developed blastocysts from embryos which spent different stages of development in vitro, indicating carryover effects of suboptimal culture conditions on epigenetic signatures of preimplantation embryos. However, epigenetic responses of in vivo originated embryos to suboptimal culture conditions are not fully understood. Therefore, here we investigated DNA methylation patterns of in vivo derived bovine embryos subjected to in vitro culture condition before, during or after major embryonic genome activation (EGA). For this, in vivo produced 2-, 8- and 16-cell stage embryos were cultured in vitro until the blastocyst stage and blastocysts were used for genome-wide DNA methylation analysis. The 2- and 8-cell flushed embryo groups showed lower blastocyst rates compared to the 16-cell flush group. This was further accompanied by increased numbers of differentially methylated genomic regions (DMRs) in blastocysts of the 2- and 8-cell flush groups compared to the complete in vivo control ones. Moreover, 1623 genomic loci including imprinted genes were hypermethylated in blastocyst of 2-, 8- and 16-cell flushed groups, indicating the presence of genomic regions which are sensitive to the in vitro culture at any stage of embryonic development. Furthermore, hypermethylated genomic loci outnumbered hypomethylated ones in blastocysts of 2- and 16-cell flushed embryo groups, but the opposite occurred in the 8-cell group. Moreover, DMRs which were unique to blastocysts of the 2-cell flushed group and inversely correlated with corresponding mRNA expression levels were involved in plasma membrane lactate transport, amino acid transport and phosphorus metabolic processes, whereas DMRs which were specific to the 8-cell group and inversely correlated with corresponding mRNA expression levels were involved in several biological processes including regulation of fatty acids and steroid biosynthesis processes. In vivo embryos subjected to in vitro culture before and during major embryonic genome activation (EGA) are prone to changes in DNA methylation marks and exposure of in vivo embryos to in vitro culture during the time of EGA increased hypomethylated genomic loci in blastocysts.

Development of the embryonic heat shock response and the impact of repeated thermal stress in early stage lake whitefish (Coregonus clupeaformis) embryos.

PubMed

Whitehouse, Lindy M; McDougall, Chance S; Stefanovic, Daniel I; Boreham, Douglas R; Somers, Christopher M; Wilson, Joanna Y; Manzon, Richard G

2017-10-01

Lake whitefish (Coregonus clupeaformis) embryos were exposed to thermal stress (TS) at different developmental stages to determine when the heat shock response (HSR) can be initiated and if it is altered by exposure to repeated TS. First, embryos were subject to one of three different TS temperatures (6, 9, or 12°C above control) at 4 points in development (21, 38, 60 and 70 days post-fertilisation (dpf)) for 2h followed by a 2h recovery to understand the ontogeny of the HSR. A second experiment explored the effects of repeated TS on the HSR in embryos from 15 to 75 dpf. Embryos were subjected to one of two TS regimes; +6°C TS for 1h every 6 days or +9°C TS for 1h every 6 days. Following a 2h recovery, a subset of embryos was sampled. Our results show that embryos could initiate a HSR via upregulation of heat shock protein 70 (hsp70) mRNA at all developmental ages studied, but that this response varied with age and was only observed with a TS of +9 or +12°C. In comparison, when embryos received multiple TS treatments, hsp70 was not induced in response to the 1h TS and 2h recovery, and a downregulation was observed at 39 dpf. Downregulation of hsp47 and hsp90α mRNA was also observed in early age embryos. Collectively, these data suggest that embryos are capable of initiating a HSR at early age and throughout embryogenesis, but that repeated TS can alter the HSR, and may result in either reduced responsiveness or a downregulation of inducible hsps. Our findings warrant further investigation into both the short- and long-term effects of repeated TS on lake whitefish development. Copyright © 2017 Elsevier Ltd. All rights reserved.

Raman spectroscopy analysis of differences in composition of spent culture media of in vitro cultured preimplantation embryos isolated from normal and fat mice dams.

PubMed

Fabian, Dušan; Kačmarová, Martina; Kubandová, Janka; Čikoš, Štefan; Koppel, Juraj

2016-06-01

The aim of the present study was to compare overall patterns of metabolic activity of in vitro cultured preimplantation embryos isolated from normal and fat mice dams by means of non-invasive profiling of spent culture media using Raman spectroscopy. To produce females with two different types of body condition (normal and fat), a previously established two-generation model was used, based on overfeeding of experimental mice during prenatal and early postnatal development. Embryos were isolated from spontaneously ovulating and naturally fertilized dams at the 2-cell stage of development and cultured to the blastocyst stage in synthetic oviductal medium KSOMaa. Embryos from fat mice (displaying significantly elevated body weight and fat) showed similar developmental capabilities in vitro as embryos isolated from normal control dams (displaying physiological body weight and fat). The results show that alterations in the composition of culture medium caused by the presence of developing mouse preimplantation embryos can be detected using Raman spectroscopy. Metabolic activity of embryos was reflected in evident changes in numerous band intensities in the 1620-1690cm(-1) (amide I) region and in the 1020-1140cm(-1) region of the Raman spectrum for KSOMaa. Moreover, multivariate analysis of spectral data proved that the composition of proteins and other organic compounds in spent samples obtained after the culture of embryos isolated from fat dams was different from that in spent samples obtained after the culture of embryos from control dams. This study demonstrates that metabolic activity of cultured preimplantation embryos might depend on the body condition of their donors. Copyright © 2016 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Ting; Zhao, Jing; Hu, Ping

Pentachlorophenol (PCP) is a prevalent pollutant in the environment and has been demonstrated to be a serious toxicant to humans and animals. However, little is known regarding the molecular mechanism underlying its toxic effects on vertebrate early development. To explore the impacts and underlying mechanisms of PCP on early development, zebrafish (Danio rerio) embryos were exposed to PCP at concentrations of 0, 20 and 50 μg/L, and microscopic observation and cDNA microarray analysis were subsequently conducted at gastrulation stage. The morphological observations revealed that PCP caused a developmental delay of zebrafish embryos in a concentration-dependent manner. Transcriptomic data showed thatmore » 50 μg/L PCP treatment resulted in significant changes in gene expression level, and the genes involved in energy metabolism and cell behavior were identified based on gene functional enrichment analysis. The energy production of embryos was influenced by PCP via the activation of glycolysis along with the inhibition of oxidative phosphorylation (OXPHOS). The results suggested that PCP acts as an inhibitor of OXPHOS at 8 hpf (hours postfertilization). Consistent with the activated glycolysis, the cell cycle activity of PCP-treated embryos was higher than the controls. These characteristics are similar to the Warburg effect, which occurs in human tumors. The microinjection of exogenous ATP confirmed that an additional energy supply could rescue PCP-treated embryos from the developmental delay due to the energy deficit. Taken together, our results demonstrated that PCP causes a Warburg-like effect on zebrafish embryos during gastrulation, and the affected embryos had the phenotype of developmental delay. - Highlights: • We treat zebrafish embryos with PCP at gastrula stage. • PCP acts as an oxidative phosphorylation inhibitor, not an uncoupler, in gastrulation. • Exogenous ATP injection will rescue the development of effected embryos. • The transcriptome of PCP-treated embryo exhibits a Warburg-like effect in tumor cell.« less

Embryonic catalase protects against ethanol embryopathies in acatalasemic mice and transgenic human catalase-expressing mice in embryo culture.

PubMed

Miller-Pinsler, Lutfiya; Wells, Peter G

2015-09-15

Reactive oxygen species (ROS) have been implicated in the mechanism of ethanol (EtOH) teratogenicity, but the protective role of the embryonic antioxidative enzyme catalase is unclear, as embryonic activity is only about 5% of maternal levels. We addressed this question in a whole embryo culture model. C57BL/6 mouse embryos expressing human catalase (hCat) or their wild-type (C57BL/6 WT) controls, and C3Ga.Cg-Cat(b)/J catalase-deficient, acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug=GD 1), exposed for 24h to 2 or 4mg/mL EtOH or vehicle, and evaluated for functional and morphological changes. hCat and C57BL/6 WT vehicle-exposed embryos developed normally, while EtOH was embryopathic in C57BL/6 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed, turning and head length, whereas hCat embryos were protected (p<0.001). Maternal pretreatment of C57BL/6 WT dams with 50kU/kg PEG-catalase (PEG-cat) 8h prior to embryo culture, which increases embryonic catalase activity, blocked all EtOH embryopathies (p<0.001). Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to WT controls, suggesting that endogenous ROS are embryopathic. EtOH was more embryopathic in aCat embryos than WT controls, evidenced by reduced head length and somite development (p<0.01), and trends for reduced anterior neuropore closure, turning and crown-rump length. Maternal pretreatment of aCat dams with PEG-Cat blocked all EtOH embryopathies (p<0.05). These data suggest that embryonic catalase is a determinant of risk for EtOH embryopathies. Copyright © 2015 Elsevier Inc. All rights reserved.

A carnivore embryo's perspective on essential amino acids and ammonium in culture medium: effects on the development of feline embryos.

PubMed

Herrick, Jason R; Lyons, Sarah M; Greene-Ermisch, Alison F; Broeckling, Corey D; Schoolcraft, William B; Krisher, Rebecca L

2018-05-18

Carnivores are an interesting model for studies of embryonic amino acid metabolism and ammonium (NH4+) toxicity given the high protein content of their diets. Our objectives were to examine concentration- and stage-specific effects of essential amino acids (EAA; 0x, 0.125x, 0.25x, 0.5x, or 1.0x the concentrations in Minimum Essential Medium) and NH4+ (0, 300, or 600 μM) on the development and metabolism of feline embryos. The presence of EAA, regardless of concentration, during days 3 to 7 of culture increased (P < 0.01) the proportion of embryos that initiated hatching (>14.3%) and the total number of cells per blastocyst (>148.3 cells) compared to embryos cultured without EAA (0.0% and 113.2 ± 3.7 cells, respectively). The presence of EAA during days 1 to 3 (0.25x) and 3 to 7 (1.0x) of culture increased (P < 0.01) the proportions of embryos that formed blastocysts (82.9 ± 4.2%) and initiated hatching (32.9 ± 5.2%), and the number of cells per blastocyst (247.9 ± 12.1 cells), compared to control embryos (60.0 ± 5.3%, 0.0%, 123.2 ± 8.1 cells, respectively). The presence of NH4+ in the medium did not affect (P > 0.05) development of feline embryos. The addition of EAA or NH4+ during culture did not affect (P > 0.05) the production of Gln by feline embryos, but decreased (P < 0.05) production of Ala and increased (P < 0.05) production of urea. Additional work is needed to determine if our observations are unique to feline embryos or reflect an adaptation to a high protein diet that is conserved in other carnivores.

Corticotrophin-releasing hormone and corticosterone impair development of preimplantation embryos by inducing oviductal cell apoptosis via activating the Fas system: an in vitro study.

PubMed

Tan, Xiu-Wen; Ji, Chang-Li; Zheng, Liang-Liang; Zhang, Jie; Yuan, Hong-Jie; Gong, Shuai; Zhu, Jiang; Tan, Jing-He

2017-08-01

What are the mechanisms by which corticotrophin-releasing hormone (CRH) and corticosterone impair the development of preimplantation embryos in the oviduct. CRH and corticosterone do not affect preimplantation embryos directly, but impair their development indirectly by triggering apoptosis of oviductal epithelial cells (OECs) through activation of the Fas system. Studies report that stress impairs embryo development with facilitated secretion of CRH and glucocorticoids. Although an in vivo study demonstrated that preimplantation stress impaired embryo development in conjunction with oviductal apoptosis and activation of the Fas system, whether CRH or glucocorticoids damage embryos directly or indirectly by way of oviductal cells remains to be clarified. Mice of Kunming strain, the generalized lymphoproliferative disorder (gld) mice with a germline mutation F273L in Fas ligand in a C57BL/6J genomic background and the wild-type C57BL/6J mice were used. Female mice were used 8-10 weeks after birth. While some female mice were killed 48 h after being injected with equine CG to collect oviducts and prepare OECs, others were killed to recover zygotes after mating with males following superovulation with eCG and hCG. The zygotes obtained were cultured with or without CRH or corticosterone (CRH/Cort) either in Chatot-Ziomek-Bavister (CZB) medium with or without OECs or in conditioned medium (CM) conditioned with OECs pretreated or not with CRH/Cort. Preimplantation development, levels of redox potential and apoptosis, and expression of CRH receptor 1 (CRHR1), glucocorticoid receptor (GR), Fas and 11β-hydroxysteroid dehydrogenase (HSD) were observed in embryos recovered at different times of in vitro culture. After culture of OECs with or without CRH/Cort, levels of redox potential and apoptosis, mRNA and protein expression of growth factors, and protein expression of CRHR1, GR and Fas were examined in OECs and the level of FasL was measured in CM. The gld mice were used to confirm a role for the Fas system in triggering apoptosis of embryos and oviducts. This study showed that blastocyst development was unaffected when mouse zygotes were cultured in CZB medium containing various concentrations of CRH/Cort but was impaired when embryos were cultured with CRH/Cort plus OECs or in CM conditioned with OECs pretreated with CRH/Cort (treatment CM). Culture in treatment-CM induced oxidative stress and apoptosis in embryos. Preimplantation embryos expressed GR and Fas at all stages and CRHR1 at the blastocyst stage only. Mouse 4-cell embryos and blastocysts expressed HSD2 but not HSD1. Culture of OECs with CRH/Cort increased their oxidative stress, apoptosis, CRHR1, Fas and FasL while decreasing their GR and growth factors. Blastocyst development in treatment-CM conditioned with OECs from gld mice harboring FasL mutations was superior to treatment-CM conditioned with wild-type mouse OECs. The results suggest that CRH/Cort impairs embryo development indirectly by inducing oviductal apoptosis via activating the Fas system. The insensitivity of preimplantation embryos to CRH and corticosterone is due to, respectively, a lack of CRHR and the exclusive expression of HSD2 that inactivate corticosterone. Not applicable. Although significant, the conclusions were drawn from limited results obtained using mice and thus they need further verification in other species. For example, bovine embryos express both HSD1 and HSD2 at all the preimplantation stages whereas mouse preimplantation embryos express HSD2 exclusively without HSD1. The data are important for our understanding of the mechanisms by which stress affects female reproduction in both human and animals, as early stages of pregnancy are considered more vulnerable to stress than the late stages. This study was supported by grants from the National Basic Research Program of China (Nos. 2014CB138503 and 2012CB944403), the China National Natural Science Foundation (Nos. 31272444 and 30972096) and the Animal breeding improvement program of Shandong Province. All authors declare that their participation in the study did not involve factual or potential conflicts of interests. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Selection for rapid embryo development correlates with embryo exposure to maternal androgens among passerine birds

USGS Publications Warehouse

Schwabl, H.; Palacios, M.G.; Martin, T.E.

2007-01-01

Greater offspring predation favors evolution of faster development among species. We hypothesized that greater offspring predation exerts selection on mothers to increase levels of anabolic androgens in egg yolks to achieve faster development. Here, we tested whether (1) concentrations of yolk androgens in passerine species were associated with offspring predation and (2) embryo and nestling development rates were associated with yolk androgen concentrations. We examined three androgens that increase in potency along the synthesis pathway: androstenedione (A4) to testosterone (T) to 5??- dihydrotestosterone (5??-DHT). Concentrations of none of these steroids were related to clutch size; only A4 was allometrically related to egg volume. Species that experience greater predation showed higher yolk concentrations of T and 5??-DHT. Higher concentrations of T and particularly 5??-DHT were strongly correlated with faster development during the embryo period and less so during the nestling period. Development rates were most strongly correlated with 5??-DHT, suggesting that potency increases along the androgen synthesis pathway and that effects are mediated by the androgen receptor pathway. These results are consistent with the hypothesis that selection for faster development by time-dependent offspring mortality may be achieved epigenetically by varying embryo exposure to maternal anabolic steroids. ?? 2007 by The University of Chicago. All rights reserved.

Survival and development of horseshoe crab (Limulus polyphemus) embryos and larvae in hypersaline conditions.

PubMed

Ehlinger, Gretchen S; Tankersley, Richard A

2004-04-01

The horseshoe crab Limulus polyphemus spawns in the mid- to upper intertidal zone where females deposit eggs in nests below the sediment surface. Although adult crabs generally inhabit subtidal regions of estuaries with salinities from 5 to 34 ppt, developing embryos and larvae within nests are often exposed to more extreme conditions of salinity and temperature during summer spawning periods. To test whether these conditions have a negative impact on early development and survival, we determined development time, survival, and molt cycle duration for L. polyphemus embryos and larvae raised at 20 combinations of salinity (range: 30-60 ppt) and temperature (range: 25-40 degrees C). Additionally, the effect of hyperosmotic and hypoosmotic shock on the osmolarity of the perivitelline fluid of embryos was determined at salinities between 5 and 90 ppt. The embryos completed their development and molted at salinities below 60 ppt, yet failed to develop at temperatures of 35 degrees C or higher. Larval survival was high at salinities of 10-70 ppt but declined significantly at more extreme salinities (i.e., 5, 80, and 90 ppt). Perivitelline fluid remained nearly isoosmotic over the range of salinities tested. Results indicate that temperature and salinity influence the rate of crab development, but only the extremes of these conditions have an effect on survival.

Stenospermy and seed development in the "Brazilian seedless" variety of sugar apple (Annona squamosa).

PubMed

Dos Santos, Rayane C; Ribeiro, Leonardo M; Mercadante-Simões, Maria Olívia; Costa, Márcia R; Nietsche, Silvia; Pereira, Marlon C T

2014-12-01

Stenospermy was identified in naturally occurring sugar-apple (Annona squamosa) mutants with great potential for use in genetic improvement programs. However, to date, there have been no detailed studies of the development of aspermic fruit in this species. The aim of the present study was to characterize the anatomy of developing fruit in the 'Brazilian Seedless' mutant. Flower buds in pre-anthesis and developing fruits were subjected to common plant anatomy techniques. The abnormal ovules are unitegmic and orthotropic and have a long funiculus. There is evidence of fertilization, including the presence of embryos in early development and the proliferation of starch grains in the embryo sac. However, the embryos and embryo sac degenerate, although this does not affect pericarp development. Ovule abortion does not occur. The perisperm, which is formed from the peripheral layers of the nucellus, fills the cavity left by the embryo sac. The mature fruit contains numerous small sterile seeds with abundant perisperm and unlignified integument that is restricted to the micropylar region. The majority of perisperm cells are living and appear to be metabolically active in the periphery. Therefore, stenospermy leads to the formation of sterile seeds in A. squamosa, and the perisperm possibly play an important role in fruit development.

Maternal aldehyde elimination during pregnancy preserves the fetal genome.

PubMed

Oberbeck, Nina; Langevin, Frédéric; King, Gareth; de Wind, Niels; Crossan, Gerry P; Patel, Ketan J

2014-09-18

Maternal metabolism provides essential nutrients to enable embryonic development. However, both mother and embryo produce reactive metabolites that can damage DNA. Here we discover how the embryo is protected from these genotoxins. Pregnant mice lacking Aldh2, a key enzyme that detoxifies reactive aldehydes, cannot support the development of embryos lacking the Fanconi anemia DNA repair pathway gene Fanca. Remarkably, transferring Aldh2(-/-)Fanca(-/-) embryos into wild-type mothers suppresses developmental defects and rescues embryonic lethality. These rescued neonates have severely depleted hematopoietic stem and progenitor cells, indicating that despite intact maternal aldehyde catabolism, fetal Aldh2 is essential for hematopoiesis. Hence, maternal and fetal aldehyde detoxification protects the developing embryo from DNA damage. Failure of this genome preservation mechanism might explain why birth defects and bone marrow failure occur in Fanconi anemia, and may have implications for fetal well-being in the many women in Southeast Asia that are genetically deficient in ALDH2. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Maternal Aldehyde Elimination during Pregnancy Preserves the Fetal Genome

PubMed Central

Oberbeck, Nina; Langevin, Frédéric; King, Gareth; de Wind, Niels; Crossan, Gerry P.; Patel, Ketan J.

2014-01-01

Summary Maternal metabolism provides essential nutrients to enable embryonic development. However, both mother and embryo produce reactive metabolites that can damage DNA. Here we discover how the embryo is protected from these genotoxins. Pregnant mice lacking Aldh2, a key enzyme that detoxifies reactive aldehydes, cannot support the development of embryos lacking the Fanconi anemia DNA repair pathway gene Fanca. Remarkably, transferring Aldh2−/−Fanca−/− embryos into wild-type mothers suppresses developmental defects and rescues embryonic lethality. These rescued neonates have severely depleted hematopoietic stem and progenitor cells, indicating that despite intact maternal aldehyde catabolism, fetal Aldh2 is essential for hematopoiesis. Hence, maternal and fetal aldehyde detoxification protects the developing embryo from DNA damage. Failure of this genome preservation mechanism might explain why birth defects and bone marrow failure occur in Fanconi anemia, and may have implications for fetal well-being in the many women in Southeast Asia that are genetically deficient in ALDH2. PMID:25155611

Applications of Tol2 Transposon-Mediated Gene Transfer for Stable Integration and Conditional Expression of Electroporated Genes in Chicken Embryos

NASA Astrophysics Data System (ADS)

Sato, Yuki; Takahashi, Yoshiko

Because of the high accessibility to developing embryos, avian embryos (chicken and quail) have long been used as a good model animal to study embryogenesis in vertebrates, especially amniotes (reviewed in Wolpert, 2004). The techniques used for “classical” avian embryology included tissue transplantations, tissue ablations, and cell-labeling by vital dye. At the end of the last century, the in ovo electropora tion technique was developed by Nakamura and his colleagues, and this modern method opened a way to study the roles of developmental genes directly in living embryos (Funahashi et al., 1999) reviewed in (Nakamura et al., 2004; Yasuda et al., 2000; Yasugi and Nakamura, 2000). This powerful technique allows us to introduce genes (DNA, RNA, morpholino) into embryos in a tissue-specific way by targeting a restricted area of embryonic tissues. Thus, the electroporation technique using chickens has provided numerous novel insights into the understanding of early development in vertebrates, making the chicken a unique model animal.

Photosynthetic potential and accumulation of assimilates in the developing chloroembryos of Cyamposis tetragonoloba (L. ) Taub

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaladharan, P.; Vivekanandan, M.

1990-02-01

The photosynthetic potential of leaves and chloroembryos of Cyamopsis tetragonoloba (L.) Taub as measured by {sup 14}C-bicarbonate fixation, Hill activity, and in vivo fluorescence transients is compared. On a chlorophyll basis, dark fixation of NaH{sup 14}CO{sub 3} in chloroembryos was 1.5 times higher than that of the leaf, whereas carbon fixation under illumination was threefold higher in the leaf than in the embryos. Rates of O{sub 2} evolution were four times more in embryo than in leaf chloroplasts. Shading of developing fruits on the day of anthesis for 10 days induced a 65% reduction in dry matter accumulation in themore » etiolated embryos, as compared to the normal green embryos of the same fruit half covered by a transparent Polythene sheet. The reduction in dry weight, size of the embryos, and levels of assimilates after shading the developing fruits may be ascribed to partial autotrophy of the chloroembryos.« less

Effects of growth hormone on the ultrastructure of bovine preimplantation embryos.

PubMed

Kölle, Sabine; Stojkovic, Miodrag; Reese, Sven; Reichenbach, Horst-Dieter; Wolf, Eckhard; Sinowatz, Fred

2004-07-01

Growth hormone (GH) has recently been shown to promote the development of preimplantation embryos. The aim of our study was therefore to analyze the effects of GH on the morphology and ultrastructure of the cells of bovine preimplantation embryos produced by in vitro fertilization (IVF). In order to determine the physiologically optimal morphology of blastocysts, ex vivo embryos obtained by uterine flushing were also included in the study. As shown by transmission electron microscopy, treatment with GH induced the elimination of glycogen storage in cells of the inner cell mass of 7-day-old embryos. GH also stimulated the exocytosis of lipid vesicles in the inner cell mass and trophectoderm cells of these embryos. Quantitative analysis of micrographs demonstrated a higher volume density of embryonic mitochondria in 7-day-old embryos cultured with GH than in control embryos. Treatment with GH regularly resulted in an improvement of the ultrastructural features of embryos produced in vitro, thus resembling the morphology of ex vivo embryos. Scanning electron-microscopy studies demonstrated that GH altered the structure and the pore size of the zona pellucida of blastocysts. Our studies imply that GH can modulate carbohydrate, lipid, and energy metabolism and influence transportation processes in the early IVF embryo.

Efficient vitrification of mouse embryos using the Kitasato Vitrification System as a novel vitrification device.

PubMed

Momozawa, Kenji; Matsuzawa, Atsushi; Tokunaga, Yukio; Abe, Shiori; Koyanagi, Yumi; Kurita, Miho; Nakano, Marina; Miyake, Takao

2017-04-24

Currently, the cryopreservation of embryos and oocytes is essential for assisted reproductive technology (ART) laboratories worldwide. This study aimed to evaluate the efficacy of the Kitasato Vitrification System (KVS) as a vitrification device for the cryopreservation of mouse embryos to determine whether this novel device can be adapted to the field of ART. In Experiment 1, blastocysts were vitrified using the KVS. Vitrified blastocysts were warmed and subsequently cultured for 72 h. In Experiment 2, 2-cell-stage embryos were vitrified using the KVS, and vitrified embryos were warmed and subsequently cultured for 96 h. In Experiment 3, we evaluated the in vivo developmental potential of vitrified 2-cell-stage embryos using the KVS, and in Experiment 4, we evaluated the cooling and warming rates for these devices using a numerical simulation. In Experiment 1, there were no significant differences between the survival rates of the KVS and a control device. However, re-expanded (100%) and hatching (91.8%) rates were significantly higher for blastocysts vitrified using the KVS. In Experiment 2, there were no significant differences between the survival rates, or rates of development to the blastocyst stage, of vitrified and fresh embryos. In Experiment 3, after embryo transfer, 41% of the embryos developed into live offspring. In Experiment 4, the cooling and warming rates of the KVS were 683,000 and 612,000 °C/min, respectively, exceeding those of the control device. Our study clearly demonstrates that the KVS is a novel vitrification device for the cryopreservation of mouse embryos at the blastocyst and 2-cell stage.

Current knowledge and future challenges in camelid reproduction.

PubMed

Tibary, A; Anouassi, A; Sghiri, A; Khatir, H

2007-01-01

Reproductive biology research on camelids offers some interesting peculiarities and challenges to scientists and animal production specialists. The objective of this paper is to review camelid reproduction, advances in reproductive physiology and reproductive biotechnologies in camelids and discuss some areas for further research. In the female, the focus has been on understanding follicular dynamics. This has allowed development of synchronization and superovulation strategies to support embryo transfer technologies which are now commonly used in camels. Some advances have been achieved in preservation of embryos by vitrification. Fertilization, early embryo development and embryo signaling for maternal recognition of pregnancy are still not fully understood. New information on the interaction of the developing embryo and the endometrium may shed some light on this signaling as well as the mechanism of prevention of luteolysis. The presence of a seminal ovulation-inducing factor (OIF) was confirmed in llamas and alpacas. Chronology of oocytes maturation has been described. In vitro production of embryos has been achieved resulting in successful pregnancies and births in the dromedary. These techniques offer a new tool for the production and study of interspecies/cross-species embryos and their effect on pregnancy. Male reproductive function remains poorly studied. Semen preservation and artificial insemination still present many challenges and are not used in production at the moment. The involvement of climatic and nutritional conditions as well as the role of leptin in the regulation of reproductive function need to be evaluated.

Genetic mouse embryo assay: improving performance and quality testing for assisted reproductive technology (ART) with a functional bioassay.

PubMed

Gilbert, Rebecca S; Nunez, Brandy; Sakurai, Kumi; Fielder, Thomas; Ni, Hsiao-Tzu

2016-03-24

Growing concerns about safety of ART on human gametes, embryos, clinical outcomes and long-term health of offspring require improved methods of risk assessment to provide functionally relevant assays for quality control testing and pre-clinical studies prior to clinical implementation. The one-cell mouse embryo assay (MEA) is the most widely used for development and quality testing of human ART products; however, concerns exist due to the insensitivity/variability of this bioassay which lacks standardization and involves subjective analysis by morphology alone rather than functional analysis of the developing embryos. We hypothesized that improvements to MEA by the use of functional molecular biomarkers could enhance sensitivity and improve detection of suboptimal materials/conditions. Fresh one-cell transgenic mouse embryos with green fluorescent protein (GFP) expression driven by Pou6f1 or Cdx2 control elements were harvested and cultured to blastocysts in varied test and control conditions to compare assessment by standard morphology alone versus the added dynamic expression of GFP for screening and selection of critical raw materials and detection of suboptimal culture conditions. Transgenic mouse embryos expressing functionally relevant biomarkers of normal early embryo development can be used to monitor the developmental impact of culture conditions. This novel approach provides a superior MEA that is more meaningful and sensitive for detection of embryotoxicity than morphological assessment alone.

Progesterone is critical for the development of mouse embryos.

PubMed

Zhang, Cong; Murphy, Bruce D

2014-08-01

Infertility affects approximately 10-15 % of reproductive-aged couples, and embryo loss due to preimplantation death is common to many mammals. Previous studies showed that a complex series of interactive molecular events are associated with this process, especially hormones (progesterone and estrogens) and growth factors, and are important for the cleavage and differentiation of the blastocysts. Yet, the mechanism of preimplantation embryo development is unclear. Using conditional knockout mice (CKO), we showed the development of blastocyst is tightly controlled by the level of progesterone (P4); furthermore, we found that the time when P4 should increase is also crucial for the formation of blastocysts. In CKO mice whose Lrh1 (liver receptor homolog 1) is deleted under the expression of Cre recombinase driven by progesterone receptor promoter, which reduced P4 synthesis, few of their embryos can reach blastocyst stage. When these CKO mice were supplied with P4 in the afternoon of dpc 1 (day post copulation), most of the embryos can form blastocysts; when CKO mice were supplied with P4 from the morning of dpc1, one-third of the embryos can reach blastocyst stage; however, the supplement of P4 in the morning of dpc 2 made very few of the embryos become blastocysts. We conclude that early exposure to P4 is essential for timely progression of early embryogenesis in the mouse.

Final Report for Regulation of Embryonic Development in Higher Plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harada, John J.

2013-10-22

The overall goal of the project was to define the cellular processes that underlie embryo development in plants at a mechanistic level. Our studies focused on a critical transcriptional regulator, Arabidopsis LEAFY COTYLEDON (LEC1), that is necessary and sufficient to induce processes required for embryo development. Because LEC1 regulates lipid accumulation during the maturation phase of embryo development, information about LEC1 may be useful in designing approaches to enhance biofuel production in plants. During the tenure of this project, we determined the molecular mechanisms by which LEC1 acts as a transcription factor in embryos. We also identified genes directly regulatedmore » by LEC1 and showed that many of these genes are involved in maturation processes. This information has been useful in dissecting the gene regulatory networks controlling embryo development. Finally, LEC1 is a novel isoform of a transcription factor that is conserved among eukaryotes, and LEC1 is active primarily in seeds. Therefore, we determined that the LEC1-type transcription factors first appeared in lycophytes during land plant evolution. Together, this study provides basic information that has implications for biofuel production.« less

Role of kinase-independent and -dependent functions of FAK in endothelial cell survival and barrier function during embryonic development.

PubMed

Zhao, Xiaofeng; Peng, Xu; Sun, Shaogang; Park, Ann Y J; Guan, Jun-Lin

2010-06-14

Focal adhesion kinase (FAK) is essential for vascular development as endothelial cell (EC)-specific knockout of FAK (conditional FAK knockout [CFKO] mice) leads to embryonic lethality. In this study, we report the differential kinase-independent and -dependent functions of FAK in vascular development by creating and analyzing an EC-specific FAK kinase-defective (KD) mutant knockin (conditional FAK knockin [CFKI]) mouse model. CFKI embryos showed apparently normal development through embryonic day (E) 13.5, whereas the majority of CFKO embryos died at the same stage. Expression of KD FAK reversed increased EC apoptosis observed with FAK deletion in embryos and in vitro through suppression of up-regulated p21. However, vessel dilation and defective angiogenesis of CFKO embryos were not rescued in CFKI embryos. ECs without FAK or expressing KD FAK showed increased permeability, abnormal distribution of vascular endothelial cadherin (VE-cadherin), and reduced VE-cadherin Y658 phosphorylation. Together, our data suggest that kinase-independent functions of FAK can support EC survival in vascular development through E13.5 but are insufficient for maintaining EC function to allow for completion of embryogenesis.

Embryotoxicity of poorly soluble nanoparticles at various stages of Zebrafish development

NASA Astrophysics Data System (ADS)

Morgaleva, Tamara; Morgalev, Yuri; Gosteva, Irina; Morgalev, Sergey; Nesterenya, Daria

2017-11-01

The biological effects of the poorly soluble nanoparticles (NPs) of different chemical nature and structural characteristics were evaluated. It was established that the Zebrafish test response to contamination of aqueous medium with nickel NPs (nNi), platinum (nPt), zinc oxide (nZnO) and cerium oxide (nCeO2) depends on the physicochemical properties of the NPs and embryo development stage. The concentrations of NPs not causing disruptions in embryonic development of Zebrafish were determined. The smallest impact on embryogenesis was exerted by nCeO2: coagulation of a small number of embryos was observed only at C = 20.0 mg/L. The same effect was observed when exposed to lower concentrations of nPt (C = 5.0 mg/L) and nNi (C = 0.1 mg/L). The greatest number of coagulated embryos was observed when grown in the DS nZnO: 37.5% of embryos died at the DS concentration of C = 0.1 mg/L. Zebrafish cultivation in the DS with low concentrations (C ≤ LC10) of nNi and nZnO caused distortions in the development of embryos: development of scoliosis, malformation of somites, inhibited mobility.

Embryonic development of lake whitefish Coregonus clupeaformis: a staging series, analysis of growth and effects of fixation.

PubMed

Sreetharan, S; Thome, C; Mitz, C; Eme, J; Mueller, C A; Hulley, E N; Manzon, R G; Somers, C M; Boreham, D R; Wilson, J Y

2015-09-01

A reference staging series of 18 morphological stages of laboratory reared lake whitefish Coregonus clupeaformis is provided. The developmental processes of blastulation, gastrulation, neurulation as well as development of the eye, circulatory system, chromatophores and mouth are included and accompanied by detailed descriptions and live imaging. Quantitative measurements of embryo size and mass were taken at each developmental stage. Eggs were 3·19 ± 0·16 mm (mean ± s.d.) in diameter at fertilization and embryos reached a total length (LT ) of 14·25 ± 0·41 mm at hatch. Separated yolk and embryo dry mass were 0·25 ± 0·08 mg and 1·39 ± 0·17 mg, respectively, at hatch. The effects of two common preservatives (formalin and ethanol) were examined throughout development and post hatch. Embryo LT significantly decreased following fixation at all points in development. A correction factor to estimate live LT from corresponding fixed LT was determined as live LT = (fixed LT )(1·025) . Eye diameter and yolk area measurements significantly increased in fixed compared with live embryos up to 85-90% development for both measurements. The described developmental stages can be generalized to teleost species, and is particularly relevant for the study of coregonid development due to additionally shared developmental characteristics. The results of this study and staging series are therefore applicable across various research streams encompassing numerous species that require accurate staging of embryos and descriptions of morphological development. © 2015 The Fisheries Society of the British Isles.

Differences in the timing of cardio-respiratory development determine whether marine gastropod embryos survive or die in hypoxia.

PubMed

Rudin-Bitterli, Tabitha S; Spicer, John I; Rundle, Simon D

2016-04-01

Physiological plasticity of early developmental stages is a key way by which organisms can survive and adapt to environmental change. We investigated developmental plasticity of aspects of the cardio-respiratory physiology of encapsulated embryos of a marine gastropod, Littorina obtusata, surviving exposure to moderate hypoxia (PO2 =8 kPa) and compared the development of these survivors with that of individuals that died before hatching. Individuals surviving hypoxia exhibited a slower rate of development and altered ontogeny of cardio-respiratory structure and function compared with normoxic controls (PO2 >20 kPa). The onset and development of the larval and adult hearts were delayed in chronological time in hypoxia, but both organs appeared earlier in developmental time and cardiac activity rates were greater. The velum, a transient, 'larval' organ thought to play a role in gas exchange, was larger in hypoxia but developed more slowly (in chronological time), and velar cilia-driven, rotational activity was lower. Despite these effects of hypoxia, 38% of individuals survived to hatching. Compared with those embryos that died during development, these surviving embryos had advanced expression of adult structures, i.e. a significantly earlier occurrence and greater activity of their adult heart and larger shells. In contrast, embryos that died retained larval cardio-respiratory features (the velum and larval heart) for longer in chronological time. Surviving embryos came from eggs with significantly higher albumen provisioning than those that died, suggesting an energetic component for advanced development of adult traits. © 2016. Published by The Company of Biologists Ltd.

Use of chick embryo in screening for teratogenicity.

PubMed

Kotwani, A

1998-04-01

A teratology screening system would detect agents hazardous to the conceptus before they can perturb embryonic development in humans. The back log of untested chemicals and the rate at which new substances enter the market exceed the developmental effects testing by standard in vivo method. Thus, cheaper, quicker in vitro systems afford a unique opportunity for investigating the direct interaction of substances with developing morphogenetic system (MGSs), since maternal influences are excluded. As a carrier of a complete set of MGSs, the chick embryo in ovo manifests an advantage over those in vitro systems that employ isolated embryos or embryonic tissues that have only limited survival. Under controlled experimental conditions including standardization of subjects, administration technique and mode of evaluation, according to the basic principles of teratology, the chick embryo test is demonstrated to be reliable and to afford quantifiable end points for evaluation. Individual compounds, mixtures of compounds and against and antagonist can easily be administered and tested. The chick embryo possesses its own basic enzyme-catalyzed drug-transformation capacity and moreover, it can be used for screening specific human metabolites. Different newer techniques e.g. chick embryotoxicity screening test (CHEST), Chick embryo blastoderm model etc are described in detail. Chick embryo fulfills all the criteria which a test should have at a lower level of tier system in teratological studies i.e. modest laboratory equipment, moderate skill, minimal expenditure of time and money, ease of accessibility of embryo, known embryological development, possibility of experimenting on a large scale for statistically valid results and whole animals are also not required.

Time-lapse cinematography-compatible polystyrene-based microwell culture system: a novel tool for tracking the development of individual bovine embryos.

PubMed

Sugimura, Satoshi; Akai, Tomonori; Somfai, Tamás; Hirayama, Muneyuki; Aikawa, Yoshio; Ohtake, Masaki; Hattori, Hideshi; Kobayashi, Shuji; Hashiyada, Yutaka; Konishi, Kazuyuki; Imai, Kei

2010-12-01

We have developed a polystyrene-based well-of-the-well (WOW) system using injection molding to track individual embryos throughout culture using time-lapse cinematography (TLC). WOW culture of bovine embryos following in vitro fertilization was compared with conventional droplet culture (control). No differences between control- and WOW-cultured embryos were observed during development to the blastocyst stage. Morphological quality and inner cell mass (ICM) and trophectoderm (TE) cell numbers were not different between control- and WOW-derived blastocysts; however, apoptosis in both the ICM and TE cells was reduced in WOW culture (P < 0.01). Oxygen consumption in WOW-derived blastocysts was closer to physiological level than that of control-derived blastocysts. Moreover, WOW culture improved embryo viability, as indicated by increased pregnancy rates at Days 30 and 60 after embryo transfer (P < 0.05). TLC monitoring was performed to evaluate the cleavage pattern and the duration of the first cell cycle of embryos from oocytes collected by ovum pickup; correlations with success of pregnancy were determined. Logistic regression analysis indicated that the cleavage pattern correlated with success of pregnancy (P < 0.05), but cell cycle length did not. Higher pregnancy rates (66.7%) were observed for animals in which transferred blastocysts had undergone normal cleavage, identified by the presence of two blastomeres of the same size without fragmentation, than among those with abnormal cleavage (33.3%). These results suggest that our microwell culture system is a powerful tool for producing and selecting healthy embryos and for identifying viability biomarkers.

Somatic embryogenesis in ferns: a new experimental system.

PubMed

Mikuła, Anna; Pożoga, Mariusz; Tomiczak, Karolina; Rybczyński, Jan J

2015-05-01

Somatic embryogenesis has never been reported in ferns. The study showed that it is much easier to evoke the acquisition and expression of embryogenic competence in ferns than in spermatophytes. We discovered that the tree fern Cyathea delgadii offers an effective model for the reproducible and rapid formation of somatic embryos on hormone-free medium. Our study provides cyto-morphological evidence for the single cell origin and development of somatic embryos. Somatic embryogenesis (SE) in both primary and secondary explants was induced on half-strength micro- and macro-nutrients Murashige and Skoog medium without the application of exogenous plant growth regulators, in darkness. The early stage of SE was characterized by sequential perpendicular cell divisions of an individual epidermal cell of etiolated stipe explant. These resulted in the formation of a linear pro-embryo. Later their development resembled that of the zygotic embryo. We defined three morphogenetic stages of fern somatic embryo development: linear, early and late embryonic leaf stage. The transition from somatic embryo to juvenile sporophyte was quick and proceeded without interruption caused by dormancy. Following 9 weeks of culture the efficiency of somatic embryogenesis reached 12-13 embryos per responding explant. Spontaneous formation of somatic embryos and callus production, which improved the effectiveness of the process sevenfold in 10-month-long culture, occurred without subculturing. The tendency for C. delgadii to propagate by SE in vitro makes this species an excellent model for studies relating to asexual embryogenesis and the endogenous hormonal regulation of that process and opens new avenues of experimentation.

Demands for carbohydrates as major energy substrates depend on the preimplantation developmental stage in pig embryos: Differential use of fructose by parthenogenetic diploids before and after the 4-cell stage in the pig

PubMed Central

SHIBUTANI, Mihiro; LEE, Jibak; MIYANO, Takashi; MIYAKE, Masashi

2015-01-01

The embryo culture technique has been improving, but the detailed demands for energy substrates such as glucose, fructose, pyruvate and lactate of preimplantation embryos are still unclear. In the present study, the demands of pig preimplantation embryos at each different developmental stage were investigated by use of parthenogenetic diploids as a model of pig preimplantation embryos. Pig parthenogenetic diploids showed different use of glucose and fructose before and after the 4-cell stage. Although glucose supported the development of pig embryos throughout the preimplantation stages and even maintained the expansion and hatching of blastocysts, it suppressed development to the blastocyst stage when glucose coexisted with pyruvate and lactate from 4 h after activation, but not after 48 h (early 4-cell stage). Since ketohexokinase that metabolizes fructose was not expressed in 2-cell and 4-cell diploids, a medium that included only fructose as a major energy substrate did not support early cleavage of pig diploids beyond the 4-cell stage, and almost no diploids developed to the morula stage just as in a medium without carbohydrates. These results may explain the different suppressive effects on pig preimplantation development between glucose and fructose when pyruvate and lactate were present in a medium. In addition, 4-cell diploids that had been cultured in a medium with pyruvate and lactate developed to the expanded blastocyst stage without any carbohydrates as a major energy substrate. These results show that the demands for carbohydrates are different depending on the developmental stage in pig preimplantation embryos. PMID:25736264

Sema4d is required for the development of the hindbrain boundary and skeletal muscle in zebrafish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Jie; Zeng, Zhen; Wei, Juncheng

2013-04-05

Highlights: ► Sema4d was expressed at all developmental stages of zebrafish. ► Knockdown of sema4d in embryos resulted in defects in the hindbrain and the trunk structure. ► Knockdown of sema4d in embryos upregulated the expression of three hindbrain rhombomere markers. ► Knockdown of sema4d in embryos increased the expression of myogenic regulatory factors. ► Knockdown of sema4d in embryos resulted in an obvious increase of cell apoptosis. -- Abstract: Semaphorin4d (SEMA4D), also known as CD100, an oligodendrocyte secreted R-Ras GTPase-activating protein (GAP), affecting axonal growth is involved in a range of processes including cell adhesion, motility, angiogenesis, immune responsesmore » and tumour progression. However, its actual physiological mechanisms and its role in development remain unclear. This study has focused on the role of sema4d in the development and expression patterns in zebrafish embryos and the effect of its suppression on development using sema4d-specific antisense morpholino-oligonucleotides. In this study the knockdown of sema4d, expressed at all developmental stages, lead to defects in the hindbrain and trunk structure of zebrafish embryos. In addition, these phenotypes appeared to be associated with the abnormal expression of three hindbrain rhombomere boundary markers, wnt1, epha4a and foxb1.2, and two myogenic regulatory factors, myod and myog. Further, a notable increase of cell apoptosis appeared in the sema4d knockdown embryos, while no obvious reduction in cell proliferation was observed. Collectively, these data suggest that sema4d plays an important role in the development of the hindbrain and skeletal muscle.« less

[Effect of TGF-beta1 on embryo implantation and development in mice in vitro].

PubMed

Luo, Shan; Yin, Hai-ning; Li, Shang-wei

2010-03-01

To investigate the role of TGF-beta1 in embryo implantation and development in vitro in mice. Mouse embryos at 2-cell stage were cultured in the media of M16 with exposure to different levels of TGF-beta1 (0, 1, 10 and 50 ng/mL). The percentage of embryos reaching fixed stages (early blastocyst, expanding blastocyst and hatched blastocyst) was monitored 68 h and 92 h after the culture. The expanding blastocys cultured for 68 h in M16 without TGF-beta1 and those with 10 ng/mL of TGF-beta1 were transferred to pseudopregnant mice. On the 6th day post transfer, the successful rates of implantation were counted. The level of IL-10/IFN-gamma in the serum and maternal-fetus interface of the mice was detected by ELISA on the 6th day post transfer. TGF-beta1 improved embryo growth in vitro. TGF-beta1 at a level of 10 ng/mL had the maximum impact, with 15.6%, 68.09%, 1.42% of embryos reaching early, expanding, and hatched stage, respectively, 68 h after culture, and 6.38%, 28.37%, 53.19% of embryos reaching early, expanding, and hatched stage, respectively, 92 h after culture. The promoting effect declined when TGF-beta1 reached 50 ng/mL. The successful rate of implantation of embryos cultured in M16 with TGF-beta1 was significantly higher than those cultured in M16 without TGF-beta1 (35. 2% vs. 17.19%, P < 0.05). The embryos cultured in M16 with TGF-beta1 had significantly lower level of IFN-gamma in the maternal-fetus interface than those cultured in M16 without TGF-beta1 [(30.89 +/- 11.31) pg/mL vs. (43.23 +/- 18. 09) pg/mL, P < 0.053. TGF-beta1 at an appropriate dose improves embryo implantation in mice in vitro. The mechanism may involve the improvement of the quality of embryos and their development, and decrease of IFN-gamma synthesis in maternal-fetal interface, a chemical that could cause Th2 bias.

Embryonic catalase protects against ethanol embryopathies in acatalasemic mice and transgenic human catalase-expressing mice in embryo culture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller-Pinsler, Lutfiya; Wells, Peter G., E-mail: pg.wells@utoronto.ca; Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario

Reactive oxygen species (ROS) have been implicated in the mechanism of ethanol (EtOH) teratogenicity, but the protective role of the embryonic antioxidative enzyme catalase is unclear, as embryonic activity is only about 5% of maternal levels. We addressed this question in a whole embryo culture model. C57BL/6 mouse embryos expressing human catalase (hCat) or their wild-type (C57BL/6 WT) controls, and C3Ga.Cg-Cat{sup b}/J catalase-deficient, acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug = GD 1), exposed for 24 h to 2 or 4 mg/mL EtOH or vehicle, and evaluated formore » functional and morphological changes. hCat and C57BL/6 WT vehicle-exposed embryos developed normally, while EtOH was embryopathic in C57BL/6 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed, turning and head length, whereas hCat embryos were protected (p < 0.001). Maternal pretreatment of C57BL/6 WT dams with 50 kU/kg PEG-catalase (PEG-cat) 8 h prior to embryo culture, which increases embryonic catalase activity, blocked all EtOH embryopathies (p < 0.001). Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to WT controls, suggesting that endogenous ROS are embryopathic. EtOH was more embryopathic in aCat embryos than WT controls, evidenced by reduced head length and somite development (p < 0.01), and trends for reduced anterior neuropore closure, turning and crown–rump length. Maternal pretreatment of aCat dams with PEG-Cat blocked all EtOH embryopathies (p < 0.05). These data suggest that embryonic catalase is a determinant of risk for EtOH embryopathies. - Highlights: • Ethanol (EtOH) exposure causes structural embryopathies in embryo culture. • Genetically enhanced catalase (hCat) protects against EtOH embryopathies. • Genetically deficient catalase (aCat) exacerbates EtOH embryopathies. • Embryonic catalase is developmentally important. • EtOH developmental toxicity involves reactive oxygen species formation.« less

Morphological analyses and variation in carbohydrate content during the maturation of somatic embryos of Carica papaya.

PubMed

Vale, Ellen Moura; Reis, Ricardo Souza; Passamani, Lucas Zanchetta; Santa-Catarina, Claudete; Silveira, Vanildo

2018-03-01

Efficient protocols for somatic embryogenesis of papaya ( Carica papaya L.) have great potential for selecting elite hybrid genotypes. Addition of polyethylene glycol (PEG), a nonplasmolyzing osmotic agent, to a maturation medium increases the production of somatic embryos in C . papaya . To study the effects of PEG on somatic embryogenesis of C . papaya , we analyzed somatic embryo development and carbohydrate profile changes during maturation treatments with PEG (6%) or without PEG (control). PEG treatment (6%) increased the number of normal mature somatic embryos followed by somatic plantlet production. In both control and PEG treatments, pro-embryogenic differentiation to the cotyledonary stage was observed and was significantly higher with PEG treatment. Histomorphological analysis of embryonic cultures with PEG revealed meristematic centers containing small isodiametric cells with dense cytoplasm and evident nuclei. Concomitant with the increase in the differentiation of somatic embryos in PEG cultures, there was an increase in the endogenous content of sucrose and starch, which appears to be related to a rising demand for energy, a key point in the conversion of C . papaya somatic embryos. The endogenous carbohydrate profile may be a valuable parameter for developing optimized protocols for the maturation of somatic embryos in papaya.

In vivo imaging and quantitative analysis of changes in axon length using transgenic zebrafish embryos.

PubMed

Kanungo, Jyotshnabala; Lantz, Susan; Paule, Merle G

2011-01-01

We describe an imaging procedure to measure axon length in zebrafish embryos in vivo. Automated fluorescent image acquisition was performed with the ImageXpress Micro high content screening reader and further analysis of axon lengths was performed on archived images using AcuityXpress software. We utilized the Neurite Outgrowth Application module with a customized protocol (journal) to measure the axons. Since higher doses of ethanol (2-2.5%, v/v) have been shown to deform motor neurons and axons during development, here we used ethanol to treat transgenic [hb9:GFP (green fluorescent protein)] zebrafish embryos at 28 hpf (hours post-fertilization). These embryos express GFP in the motor neurons and their axons. Embryos after ethanol treatment were arrayed in 384-well plates for automated fluorescent image acquisition in vivo. Average axon lengths of high dose ethanol-treated embryos were significantly lower than the control. Another experiment showed that there was no significant difference in the axon lengths between the embryos grown for 24h at 22°C and 28.5°C. These test experiments demonstrate that using axon development as an end-point, compound screening can be performed in a time-efficient manner. Published by Elsevier Inc.

Better Quality and More Usable Embryos Obtained on Day 3 Cultured in 5% Than 20% Oxygen: A Controlled and Randomized Study Using the Sibling Oocytes.

PubMed

Peng, Huixia; Shi, Wenhao; Zhang, Wei; Xue, Xia; Li, Na; Li, Wei; Shi, Juanzi

2016-03-01

To evaluate the effect of atmospheric oxygen (O2) concentration on embryonic development, a controlled and randomized study using the sibling oocytes was carried out. A total of 147 patients were studied. Embryos were cultured in O2 concentration 20% versus 5% during the gamete, zygote, and first 3 days. The mean cell numbers of embryo (7.69 ± 1.91 vs 7.20 ± 1.82, P = .011) and rate of clinically useable embryos (81.62% vs 77.22%, P = .017) were significantly higher in 5% O2 than in 20% O2. There was no difference in the zygote developmental stage, day 2, day 4, and blastocyst stage. The quality of blastocyst (both inner cell mass and trophectoderm) showed no difference. Also, there was no increase in embryos fragmentation and uneven cells in 20% O2 culture condition. In conclusion, 20% O2 reduced the mean cell numbers of embryo and the number of clinically useable embryos on day 3. However, there was no subsequent negative impact on development of day 4 and blastocyst stage. © The Author(s) 2015.

Embryo mechanics: balancing force production with elastic resistance during morphogenesis.

PubMed

Davidson, Lance A

2011-01-01

Morphogenesis requires the spatial and temporal control of embryo mechanics, including force production and mechanical resistance to those forces, to coordinate tissue deformation and large-scale movements. Thus, biomechanical processes play a key role in directly shaping the embryo. Additional roles for embryo mechanics during development may include the patterning of positional information and to provide feedback to ensure the success of morphogenetic movements in shaping the larval body and organs. To understand the multiple roles of mechanics during development requires familiarity with engineering principles of the mechanics of structures, the viscoelastic properties of biomaterials, and the integration of force and stress within embryonic structures as morphogenesis progresses. In this chapter, we review the basic engineering principles of biomechanics as they relate to morphogenesis, introduce methods for quantifying embryo mechanics and the limitations of these methods, and outline a formalism for investigating the role of embryo mechanics in birth defects. We encourage the nascent field of embryo mechanics to adopt standard engineering terms and test methods so that studies of diverse organisms can be compared and universal biomechanical principles can be revealed. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of embryo density on in vitro developmental characteristics of bovine preimplantative embryos with respect to micro and macroenvironments.

PubMed

Hoelker, M; Rings, F; Lund, Q; Phatsara, C; Schellander, K; Tesfaye, D

2010-10-01

To overcome developmental problems as a consequence of single embryo culture, the Well of the Well (WOW) culture system has been developed. In this study, we aimed to examine the effect of embryo densities with respect to both microenvironment and macroenvironment on developmental rates and embryo quality to get a deeper insight into developmentally important mechanisms. WOW diameter and depth significantly affected developmental rates (p < 0.05). WOWs with diameter of 500 μm reached significantly higher blastocyst rates (32.5 vs 21.1% vs 20.3%) compared to embryos cultured in WOWs of 300 μm diameter or plain cultured controls. Embryos cultured in WOWs with 700 μm depth reached significant higher developmental rates compared with embryos cultured in WOWs of 300 μm depth and control embryos (30.6 vs 22.6% vs 20.3%). Correlation of the embryo per WOW volume with developmental rates was higher (r(2) = 0.92, p = 0.0004) than correlation of WOW diameter or WOW depth with developmental rates. However, the embryo per WOW volume did not affect differential cell counts. An embryo per culture dish volume of 1 : 30 μl was identified to be optimal when the embryo per WOW volume was 1 : 0.27 μl increasing developmental rates up to the level of mass embryo production. Giving the opportunity to track each embryo over the complete culture period while keeping high developmental rates with normal mitotic dynamics, the results of this work will provide benefit for the single culture of embryos in human assisted reproduction, mammalian embryos with high economic interest as well as for scientific purpose. © 2009 Blackwell Verlag GmbH.

United States Coast Guard: Officer Corps Military Professional Development Program

DTIC Science & Technology

2011-06-10

captain relieved of command after viewing porn on computer,‖ 10 July 2010, http://www.thenewstribune.com/2010/07/ 10/1259108/portland-coast-guard...Coast Guard captain relieved of command after viewing porn on computer,‖ 10 July 2010. http://www.thenewstribune.com/2010/07/ 10/1259108/portland

Development of frozen-thawed demi-embryos and production of identical twin calves of different ages.

PubMed

Seike, N; Sakai, M; Kanagawa, H

1991-02-01

The percentages of morphologically transferable embryos obtained from frozen-thawed demi-embryos which were embedded with or without agar, and from those with or without zonae pellucidae were 26.3% (5/19), 36.4% (8/22), 39.5% (15/38) and 40.0% (22/55), respectively. No significant differences were observed between these groups. Development to calves of frozen-thawed demi-embryos with or without zonae pellucidae was 25.0% (3/12) and 26.7% (4/15), respectively. There was also no significant difference between them. On the trial for production of identical twin calves of different ages, the pregnancy rates of fresh and frozen demi-embryos after transfer were 69.2% (9/13) and 11.1% (1/9), respectively. Out of 13 fresh demi-embryos and 9 frozen demi-embryos transferred, only one pair of identical twin male calves of different ages were produced. This frozen-thawed demi-embryo was stored for 43 days in liquid nitrogen before thawing and transfer. These twin calves were confirmed to be identical by blood typing. Although these calves had different birth dates, their growth rates indicated similar developmental patterns. We suggest that it is possible to produce identical twin calves of different ages. This possibility would be useful for predicting the sex, milk producing ability and progeny test of a pair of demi-embryos before a decision to transfer the other half of a pair is made.

SULFATE-SULFUR METABOLISM IN THE RAT FETUS AS INDICATED BY SULFUR-35

PubMed Central

Dziewiatkowski, Dominic D.

1953-01-01

Twenty-four hours after the intraperitoneal injection of sodium sulfate-S35 into pregnant rats, sulfur-35 was found in the embryos. The amount of the sulfur-35 retained by the embryos was directly related to their degree of development in utero. A large fraction of the sulfur-35 found in the embryos was insoluble in 5 per cent trichloroacetic acid. At the 9th to 10th day of development, about 40 per cent of the sulfur-35 was present in this fraction. In 20-day-old embryos this fraction accounted for nearly 90 per cent of the total. Radioautographs of sections of embryos fixed in a solution of formaldehyde revealed that the sulfur-35 was most highly concentrated in the cartilaginous portion of the skeleton. All other tissues gave much weaker autographic reactions, comparable with the over-all reaction obtained when sections from embryos fixed in a solution of formaldehyde saturated with barium hydroxide were used. By analysis for the sulfur-35 content of individual tissues the concentration of the sulfur-35 in humeri from 20-day-old embryos was found to be about 30 times that in the maternal sternum. The concentration of the isotope in the skeletal muscle, brain, heart, and skin of the same embryos was also higher than in the corresponding maternal tissues. On the other hand, the concentration of the sulfur-35 in the maternal gastrointestinal tract plus contents was higher than in the gastrointestinal tract and contents of the embryos. PMID:13069655

Cloned embryos from semen. Part 2: Intergeneric nuclear transfer of semen-derived eland (Taurotragus oryx) epithelial cells into bovine oocytes

USGS Publications Warehouse

Nel-Themaat, L.; Gomez, M.C.; Pope, C.E.; Lopez, M.; Wirtu, G.; Jenkins, J.A.; Cole, A.; Dresser, B.L.; Bondioli, K.R.; Godke, R.A.

2008-01-01

The production of cloned offspring by nuclear transfer (NT) of semen-derived somatic cells holds considerable potential for the incorporation of novel genes into endangered species populations. Because oocytes from endangered species are scarce, domestic species oocytes are often used as cytoplasts for interspecies NT. In the present study, epithelial cells isolated from eland semen were used for intergeneric transfer (IgNT) into enucleated bovine oocytes and compared with bovine NT embryos. Cleavage rates of bovine NT and eland IgNT embryos were similar (80 vs. 83%, respectively; p > 0.05); however, development to the morula and blastocyst stage was higher for bovine NT embryos (38 and 21%, respectively; p < 0.0001), than for eland IgNT embryos (0.5 and 0%, respectively). DNA synthesis was not observed in either bovine NT or eland IgNT cybrids before activation, but in 75 and 70% of bovine NT and eland igNT embryos, respectively, cell-cycle resumption was observed at 16 h postactivation (hpa). For eland IgNT embryos, 13% had ???8 cells at 84 hpa, while 32% of the bovine NT embryos had ???8 cells at the same interval. However, 100 and 66% of bovine NT and eland IgNT embryos, respectively, that had ???8 cells synthesized DNA. From these results we concluded that (1) semen-derived epithelial cell nuclei can interact and be transcriptionally controlled by bovine cytoplast, (2) the first cell-cycle occurred in IgNT embryos, (3) a high frequency of developmental arrest occurs before the eight-cell stage in IgNT embryos, and (4) IgNT embryos that progress through the early cleavage stage arrest can (a) synthesize DNA, (b) progress through subsequent cell cycles, and (c) may have the potential to develop further. ?? 2008 Mary Ann Liebert, Inc.

Comparison of in Situ and in Vitro Regulation of Soybean Seed Growth and Development

PubMed Central

Dyer, Daniel J.; Cotterman, C. Daniel; Cotterman, Josephine C.

1987-01-01

The growth characteristics of soybean (Glycine max [L.] Merr.) embryos in culture and seeds in situ were found to be similar, but developmental differences were observed. Embryos placed in culture when very small (<2 milligrams dry weight) failed to attain the maximal growth rates attained by embryos which were more mature when placed in culture. When nutrient levels were maintained in the culture medium, embryos continued to grow indefinitely, reaching dry weights far in excess of seeds matured in situ. Apparently, maternal factors were important in early and late development during the determination of maximum growth rate and the cessation of growth. Embryo growth rate was not affected by substituting glucose plus fructose for sucrose in the medium, nor by hormone treatments, including abscisic acid. Glutamine was found to give substantially better growth than glutamate, however. Contrary to prior reports, the response of soybean embryo growth rate to irradiance was found to be primarily an artifact of the effect of irradiance on media temperature. Across seven genotypes the correlation coefficient between seed growth rate in situ and embryo growth rate in vitro was 0.94, indicating essentially all of the variability of in situ seed growth rate between cultivars could be attributed to inherent growth rate differences associated with the embryos. The response to temperature was very similar for both embryos in culture and seeds in situ at temperatures below 30°C. Beyond that temperature, embryo growth rate continued to increase, while seed growth rate did not. The implication is that in situ seed growth rate is determined by the inherent growth potential of the embryo at low to moderate temperatures; however, at higher temperatures, the maternal plant is unable to support the rapid growth rates that the embryo is capable of attaining under conditions of unlimited assimilate supply. PMID:16665434

Live dynamic analysis of the developing cardiovascular system in mice

NASA Astrophysics Data System (ADS)

Lopez, Andrew L.; Wang, Shang; Larin, Kirill V.; Larina, Irina V.

2017-02-01

The study of the developing cardiovascular system in mice is important for understanding human cardiogenesis and congenital heart defects. Our research focuses on imaging early development in the mouse embryo to specifically understand cardiovascular development under the regulation of dynamic factors like contractile force and blood flow using optical coherence tomography (OCT). We have previously developed an OCT based approach that combines static embryo culture and advanced image processing with computational modeling to live-image mouse embryos and obtain 4D (3D+time) cardiodynamic datasets. Here we present live 4D dynamic blood flow imaging of the early embryonic mouse heart in correlation with heart wall movement. We are using this approach to understand how specific mutations impact heart wall dynamics, and how this influences flow patterns and cardiogenesis. We perform studies in mutant embryos with cardiac phenotypes such as myosin regulatory light chain 2, atrial isoform (Mlc2a). This work is brings us closer to understanding the connections between dynamic mechanical factors and gene programs responsible for early cardiovascular development.

Chronic toxicity of copper on embryo development in Chinese toad, Bufo gargarizans.

PubMed

Xia, Kun; Zhao, Hongfeng; Wu, Minyao; Wang, Hongyuan

2012-06-01

This study examined the effects of copper exposure on embryonic development of Chinese toad, Bufo gargarizans. Firstly, the LC(50) values from 24 to 96 h of exposure were 3.61×10(-6) M, by means of a 4 d toxicity test with B. gargarizans embryos. Secondly, Chinese toad embryos were exposed to 10(-9)-10(-6) M copper from mid gastrula stage to operculum completion stage. Measurements included mortality, tadpole weight, tadpole total length, growth retardation, duration of different embryo stages and malformation. Embryonic survival was not affected by copper. Relative to control tadpoles, significantly decreased weight and total length were found at 10(-9)-10(-6) M reduced percentage of the embryos in right operculum stage after 10 d exposure to copper and reduced percentage of embryos in operculum completion stage after 12 d exposure to copper were also observed. Moreover, the duration of embryonic development increased at neural, circulation and operculum development stage in copper-treated groups. For the scanning microscope and histological observation, the abnormalities were malformation of wavy dorsal fin, flexural tail, curvature body axis, yolk sac oedema and reduced pigmentation in the yolk sac. Histopathological changes in olfactory, retinal epithelium and skin were also observed. DNA strand breaks exposed to the copper were analyzed by DNA ladder. In conclusion, copper induced toxic effects on B. gargarizans embryos. The present study indicated chronic toxicity tests may provide more accurate way in formulating the "safe levels" of heavy metals to amphibian. Copyright © 2012 Elsevier Ltd. All rights reserved.

The effects of cobalt on the development, oxidative stress, and apoptosis in zebrafish embryos.

PubMed

Cai, Guiquan; Zhu, Junfeng; Shen, Chao; Cui, Yimin; Du, Jiulin; Chen, Xiaodong

2012-12-01

Metal-on-metal hip arthroplasty has been performed with increasing frequency throughout the world, particularly in younger and more active patients, including women of childbearing age. The potential toxicity of cobalt exposure on fetus is concerned since cobalt ions generated by metal-on-metal bearings can traverse the placenta and be detected in fetal blood and amniotic fluid. This study examined the effects of cobalt exposure on early embryonic development and the mechanisms underlying its toxicity. Zebrafish embryos were exposed to a range of cobalt concentrations (0-100 mg/L) between 1 and 144 h postfertilization. The survival and early development of embryos were not significantly affected by cobalt at concentrations <100 μg/L. However, embryos exposed to higher concentrations (>100 μg/L) displayed reduced survival rates and abnormal development, including delayed hatching, aberrant morphology, retarded growth, and bradycardia. Furthermore, this study examined oxidative stress and apoptosis in embryos exposed to cobalt at concentrations of 0-500 μg/L. Lipid peroxidation levels were increased in cobalt-treated embryos at concentrations of 100 and 500 μg/L. The mRNA levels of catalase, superoxide dismutase 2, p53, caspase-3, and caspase-9 genes were upregulated in a dose-dependent manner. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays also revealed abnormal apoptotic signals in the brain, trunk, and tail when treated with 500 μg/L cobalt. These data suggest that oxidative stress and apoptosis are associated with cobalt toxicity in zebrafish embryos.

Combined endosulfan and cypermethrin-induced toxicity to embryo-larval development of Rhinella arenarum.

PubMed

Svartz, Gabriela V; Aronzon, Carolina M; Pérez Coll, Cristina S

2016-01-01

The combined effects of two widely used pesticides, endosulfan and cypermethrin, on survival of embryo-larval development of the South American toad (Rhinella arenarum) were examined. The toxicity bioassays were performed according to the AMPHITOX test. Embryos and larvae were exposed to mixtures of these pesticides at equitoxic ratios from acute or chronic exposure to evaluate interaction effects. The results were analyzed using both Marking's additive index and combination index (CI)-isobologram methods. Acute (96-h) and intermediate (168-h) toxicity of endosulfan-cypermethrin mixtures remained almost constant for larvae and embryos, but when exposure duration was increased, there was a significant elevation in toxicity, obtaining chronic (240-h) no-observed-effect concentrations (NOEC) values of 0.045 and 0.16 mg/L for embryos and larvae, respectively. These are environmentally relevant concentrations that reflect a realistic risk of this pesticide mixture to this native amphibian species. The toxicity increment with the exposure duration was coincident with the central nervous system development on embryos reaching the larval period, the main target organ of these pesticides. The interactions of the pesticide mixtures at acute and chronic exposure were antagonistic for embryo development (CI > 1), and additive (CI = 1) for larvae, while chronic exposure interactions were synergistic (CI < 1) for both developmental periods. Data indicated that endosulfan-cypermethrin mixtures resulted in different interaction types depending on duration and developmental stage exposed. As a general pattern and considering conditions of overall developmental period and chronic exposure, this pesticide mixture usually applied in Argentine crop fields is synergistic with respect to toxicity for this native amphibian species.

Turbulence, cleavage, and the naked embryo: a case for coral clones.

PubMed

Heyward, A J; Negri, A P

2012-03-02

After mass spawning events, coral embryos, lacking the protective capsule of other metazoans, are directly exposed to the environment at the ocean surface. Here, we present evidence that modest turbulence disrupts the integrity of these embryos, which fragment into totipotent cells that develop into proportionately smaller functional larvae. The level of turbulence required to fragment coral embryos can be generated from small wind-generated waves, which occur frequently during coral spawning on the Great Barrier Reef. The formation of planktonic coral clones, through natural embryo fragmentation of broadcast spawn, is a previously unknown mode of reproduction in the animal kingdom.

Embryo Development inside Female Salamander (Ambystoma jeffersonianum-laterale) Prior to Egg Laying

PubMed Central

Charney, Noah D.; Castorino, John J.; Dobro, Megan J.; Steely, Sarah L.

2014-01-01

The length of embryo retention prior to oviposition is a critical evolutionary trait. In all oviparous salamanders, which include the vast majority of species in the order, fertilization is thought to occur at the time of egg laying. Embryos then enter the first cleavage stage several hours after being deposited. This pattern holds for previously studied individuals in the Ambystoma jeffersonianum-laterale complex. Here, we document an instance in which a female Ambystoma jeffersonianum-laterale was carrying embryos internally that had already reached stage 10 of development. Development likely began several days prior to the start of migration to the breeding pond. This is the first such record for any egg-laying salamander, and suggests a degree of plasticity in the timing of fertilization and development not previously recognized. Further work is needed to ascertain the prevalence, mechanics, and evolutionary significance of this phenomenon. PMID:24651275

Synchronization of Somatic Embryogenesis in Date Palm Suspension Culture Using Abscisic Acid.

PubMed

Alwael, Hussain A; Naik, Poornananda M; Al-Khayri, Jameel M

2017-01-01

Somatic embryogenesis is considered the most effective method for commercial propagation of date palm. However, the limitation of obtaining synchronized development of somatic embryos remains an impediment. The synchronization of somatic embryo development is ideal for the applications to produce artificial seeds. Abscisic acid (ABA) is associated with stress response and influences in vitro growth and development. This chapter describes an effective method to achieve synchronized development of somatic embryos in date palm cell suspension culture. Among the ABA concentrations tested (0, 1, 10, 50, 100 μM), the best synchronized growth was obtained in response to 50-100 μM. Here we provide a comprehensive protocol for in vitro plant regeneration of date palm starting with shoot-tip explant, callus initiation and growth, cell suspension establishment, embryogenesis synchronization with ABA treatment, somatic embryo germination, and rooting as well as acclimatized plantlet establishment.

Gluconeogenesis, non-essential amino acid synthesis and substrate partitioning in chicken embryos during later development.

PubMed

Hu, Q; Agarwal, U; Bequette, B J

2017-02-01

We aimed to quantify the rate of gluconeogenesis (GNG), non-essential amino-acid (NEAA) synthesis, and substrate partitioning to the Krebs cycle in embryonic (e) day e14 and e19 chicken embryos. An in ovo continuous tracer infusion approach was employed to test the hypotheses that GNG and NEAA synthesis in developing chicken embryo increases from e14 to e19. [ 13 C 6 ]Glucose or [ 13 C 3 ]glycerol was continuously infused (8 h) into the chorio-allantoic compartment of eggs on e14 and e19. Glucose entry rate, Cori cycling, and GNG were higher (P < 0.05) in e19 compared to e14 embryos, presumably to support higher glycogen deposition in liver and muscle. Whereas de novo synthesis of alanine, aspartate, and glutamate via glycolysis and the Krebs cycle was higher (P < 0.01) in e14 embryos, synthesis of these NEAA from glycerol was higher (P < 0.05) in e19 compared to e14 embryos. These patterns of glucose and glycerol utilization suggest a metabolic shift to conserve glucose for glycogen synthesis and an increased utilization of yolk glycerol (from triacylglyceride) after e14. Although the contribution of glycerol to GNG in e19 embryos was higher (P < 0.05) than that in e14 embryos, the contribution of glycerol to GNG (1.3 to 6.0%) was minor. Based on [ 13 C 6 ]glucose tracer kinetics, the activities of both pyruvate carboxylase (PC) and pyruvate dehydrogenase (PDH) in the liver were higher (P < 0.05) in e19 embryos; whereas the higher (P < 0.01) relative activity of liver PC compared to PDH in e14 embryos suggests a greater anaplerotic flux into the Krebs cycle. In summary, the in ovo continuous tracer infusion approach allowed for a measurement of chicken embryo whole body and liver metabolism over a shorter window of development. This study provided quantitative estimates of the developmental shifts in substrate utilization, GNG, and NEAA synthesis by chicken embryos, as well as qualitative estimates of the activities of enzymes central to the Krebs cycle, glucose, and fatty acid metabolism. © 2016 Poultry Science Association Inc.

Auxin Import and Local Auxin Biosynthesis Are Required for Mitotic Divisions, Cell Expansion and Cell Specification during Female Gametophyte Development in Arabidopsis thaliana

PubMed Central

Panoli, Aneesh; Martin, Maria Victoria; Alandete-Saez, Monica; Simon, Marissa; Neff, Christina; Swarup, Ranjan; Bellido, Andrés; Yuan, Li; Pagnussat, Gabriela C.; Sundaresan, Venkatesan

2015-01-01

The female gametophyte of flowering plants, called the embryo sac, develops from a haploid cell named the functional megaspore, which is specified after meiosis by the diploid sporophyte. In Arabidopsis, the functional megaspore undergoes three syncitial mitotic divisions followed by cellularization to form seven cells of four cell types including two female gametes. The plant hormone auxin is important for sporophytic developmental processes, and auxin levels are known to be regulated by biosynthesis and transport. Here, we investigated the role of auxin biosynthetic genes and auxin influx carriers in embryo sac development. We find that genes from the YUCCA/TAA pathway (YUC1, YUC2, YUC8, TAA1, TAR2) are expressed asymmetrically in the developing ovule and embryo sac from the two-nuclear syncitial stage until cellularization. Mutants for YUC1 and YUC2 exhibited defects in cell specification, whereas mutations in YUC8, as well as mutations in TAA1 and TAR2, caused defects in nuclear proliferation, vacuole formation and anisotropic growth of the embryo sac. Additionally, expression of the auxin influx carriers AUX1 and LAX1 were observed at the micropylar pole of the embryo sac and in the adjacent cells of the ovule, and the aux1 lax1 lax2 triple mutant shows multiple gametophyte defects. These results indicate that both localized auxin biosynthesis and auxin import, are required for mitotic divisions, cell expansion and patterning during embryo sac development. PMID:25970627

Periods of cardiovascular susceptibility to hypoxia in embryonic american alligators (Alligator mississippiensis)

PubMed Central

Tate, Kevin B.; Rhen, Turk; Eme, John; Kohl, Zachary F.; Crossley, Janna; Elsey, Ruth M.

2016-01-01

During embryonic development, environmental perturbations can affect organisms' developing phenotype, a process known as developmental plasticity. Resulting phenotypic changes can occur during discrete, critical windows of development. Critical windows are periods when developing embryos are most susceptible to these perturbations. We have previously documented that hypoxia reduces embryo size and increases relative heart mass in American alligator, and this study identified critical windows when hypoxia altered morphological, cardiovascular function and cardiac gene expression of alligator embryos. We hypothesized that incubation in hypoxia (10% O2) would increase relative cardiac size due to cardiac enlargement rather than suppression of somatic growth. We exposed alligator embryos to hypoxia during discrete incubation periods to target windows where the embryonic phenotype is altered. Hypoxia affected heart growth between 20 and 40% of embryonic incubation, whereas somatic growth was affected between 70 and 90% of incubation. Arterial pressure was depressed by hypoxic exposure during 50–70% of incubation, whereas heart rate was depressed in embryos exposed to hypoxia during a period spanning 70–90% of incubation. Expression of Vegf and PdgfB was increased in certain hypoxia-exposed embryo treatment groups, and hypoxia toward the end of incubation altered β-adrenergic tone for arterial pressure and heart rate. It is well known that hypoxia exposure can alter embryonic development, and in the present study, we have identified brief, discrete windows that alter the morphology, cardiovascular physiology, and gene expression in embryonic American alligator. PMID:27101296

Auxin Import and Local Auxin Biosynthesis Are Required for Mitotic Divisions, Cell Expansion and Cell Specification during Female Gametophyte Development in Arabidopsis thaliana.

PubMed

Panoli, Aneesh; Martin, Maria Victoria; Alandete-Saez, Monica; Simon, Marissa; Neff, Christina; Swarup, Ranjan; Bellido, Andrés; Yuan, Li; Pagnussat, Gabriela C; Sundaresan, Venkatesan

2015-01-01

The female gametophyte of flowering plants, called the embryo sac, develops from a haploid cell named the functional megaspore, which is specified after meiosis by the diploid sporophyte. In Arabidopsis, the functional megaspore undergoes three syncitial mitotic divisions followed by cellularization to form seven cells of four cell types including two female gametes. The plant hormone auxin is important for sporophytic developmental processes, and auxin levels are known to be regulated by biosynthesis and transport. Here, we investigated the role of auxin biosynthetic genes and auxin influx carriers in embryo sac development. We find that genes from the YUCCA/TAA pathway (YUC1, YUC2, YUC8, TAA1, TAR2) are expressed asymmetrically in the developing ovule and embryo sac from the two-nuclear syncitial stage until cellularization. Mutants for YUC1 and YUC2 exhibited defects in cell specification, whereas mutations in YUC8, as well as mutations in TAA1 and TAR2, caused defects in nuclear proliferation, vacuole formation and anisotropic growth of the embryo sac. Additionally, expression of the auxin influx carriers AUX1 and LAX1 were observed at the micropylar pole of the embryo sac and in the adjacent cells of the ovule, and the aux1 lax1 lax2 triple mutant shows multiple gametophyte defects. These results indicate that both localized auxin biosynthesis and auxin import, are required for mitotic divisions, cell expansion and patterning during embryo sac development.

Hatching behavior of eastern long-necked turtles (Chelodina longicollis): The influence of asynchronous environments on embryonic heart rate and phenotype.

PubMed

McGlashan, Jessica K; Loudon, Fiona K; Thompson, Michael B; Spencer, Ricky-John

2015-10-01

Variable temperatures within a nest cause asynchronous development within clutches of freshwater turtle embryos, yet synchronous hatching occurs and is thought to be an important survival strategy for hatchlings. Metabolic compensation and circadian rhythms in heart rates of embryonic turtles indicate the potential of communication between embryos in a nest. Heart rates were used to identify metabolic circadian rhythms in clutches of an Australian freshwater turtle (Chelodina longicollis) and determine whether embryos metabolically compensate and hatch synchronously when incubated in asynchronous environments. The effects of a group environment during incubation on egg development and incubation period were also investigated during the final 3 weeks of development. Chelodina longicollis hatch synchronously and metabolically compensate so that less advanced embryos catch up to more advanced clutch-mates. Heart rates of embryos remained stable from week 4-7 in asynchronous (M=89 bpm) and synchronous (M=92 bpm) groups and declined in the final 2 weeks of incubation (M=72 and 77 bpm). Circadian rhythms were present throughout development and diel heart rates of embryos in asynchronous groups showed less deviation from the mean (M=-0.5 bpm) than synchronous groups (M=-4 bpm). Eggs incubated in groups had a significantly shorter incubation period than eggs incubated individually. Phenotypic traits including size, performance, and growth of all hatchlings were not affected. Egg position within a turtle nest is important for coordinating development throughout incubation and facilitating synchronous hatching. Copyright © 2015 Elsevier Inc. All rights reserved.

DPPA3 prevents cytosine hydroxymethylation of the maternal pronucleus and is required for normal development in bovine embryos.

PubMed

Bakhtari, Azizollah; Ross, Pablo J

2014-09-01

Dppa3 has been described in mice as an important maternal factor contributed by the oocyte that participates in protecting the maternal genome from oxidation of methylated cytosines (5mC) to hydroxymethylated cytosines (5hmC). Dppa3 is also required for normal mouse preimplantation development. This gene is poorly conserved across mammalian species, with less than 32% of protein sequence shared between mouse, cow and human. RNA-seq analysis of bovine oocytes and preimplantation embryos revealed that DPPA3 transcripts are some of the most highly abundant mRNAs in the oocyte, and their levels gradually decrease toward the time of embryonic genome activation (EGA). Knockdown of DPPA3 by injection of siRNA in germinal vesicle (GV) stage oocytes was used to assess its role in epigenetic remodeling and embryo development. DPPA3 knockdown resulted in increased intensity of 5hmC staining in the maternal pronucleus (PN), demonstrating a role for this factor in the asymmetric remodeling of the maternal and paternal PN in bovine zygotes. Also, DPPA3 knockdown decreased the developmental competence of parthenogenetic and in vitro fertilized embryos. Finally, DPPA3 knockdown embryos that reached the blastocyst stage had significantly fewer ICM cells as compared with control embryos. We conclude that DPPA3 is a maternal factor important for correct epigenetic remodeling and normal embryonic development in cattle, indicating that the role of DPPA3 during early development is conserved between species.

Morphological evaluation of Day 8 embryos developed during induced aluteal cycles in the mare.

PubMed

Leisinger, C A; Medina, V; Markle, M L; Paccamonti, D L; Pinto, C R F

2018-01-01

A novel in vivo model utilizing serial administrations of PGF 2α to induce aluteal cycles in the mare was used to evaluate the effects of progesterone-deprivation on the morphology of in vivo preimplantation embryos. We hypothesized that equine embryos produced during induced aluteal cycles (AL) would be developmentally affected, characterized by earlier embryo stage at collection, smaller embryo diameter, and lower quality grade, compared with those collected on the same day post-ovulation from control cycles during diestrus (high progesterone; > 4 ng/mL). Seven cyclic mares with a median age of 6.5 years (range 3-16) were utilized in a crossover design. Mares in estrus were artificially inseminated to a fertile stallion and randomly assigned to control or AL groups. Mares received either saline solution (control mares) or PGF 2α (AL mares), twice daily on days 0, 1, and 2 and once daily on days 3 and 4. Serial blood samples were collected daily during estrus and until the day of embryo collection 8 days after ovulation. Mares were monitored until they returned to estrus, and artificially inseminated. Mares were switched to the opposite treatment group only after a successful embryo collection occurred during the previous cycle. Only cycles that produced embryos were used for analyses. No significant rise in progesterone was observed in the AL group with mean concentrations of plasma progesterone remaining <1.0 ng/mL from ovulation until embryo collection on Day 8. This is in sharp contrast to the control (luteal) cycle where a post-ovulatory rise in plasma progesterone was observed. The mean daily concentrations of plasma progesterone were significantly higher in control vs. AL group beginning at Day 3 and remained so until Day 8. The mean (±SEM) embryo diameter of AL embryos was 171 ± 5 μm compared to 756 ± 99 μm for control embryos. The majority of the Day 8 AL embryos were classified as morulas (3/9) or early blastocysts (5/9) with only 2 embryos of quality grade 1 compared to the Day 8 control embryos that were mostly expanded blastocysts (6/7) with 5 of 6 being of quality grade 1. This study shows that serial administrations of PGF 2α were able to prevent significant rises in plasma progesterone, thus inducing aluteal cycles characterized by a progesterone-deprived environment for developing embryos. Embryos collected from induced aluteal cycles were adversely affected as demonstrated by a lower quality grade, smaller diameter and earlier embryo stage at collection when compared to control embryos. Copyright © 2017 Elsevier Inc. All rights reserved.

Eye and tentacle abnormalities in embryos of the atlantic oyster drill, Urosalpinx cinerea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinhart, K.; Myers, T.D.

1975-12-01

Multiple development of eyes and cephalic tentacles was observed in developing embryos of the Atlantic oyster drill, Urosalpinx cinerea. These abnormalities were found in 2.7 percent of embryos previously exposed to 0.01 ppM mercuric chloride and in 0.4 percent of control animals. Animals were noted with one to three tentacles and one to six eyes. The most prevalent combination of abnormalities observed was three eyes and two tentacles per animal.

Mitochondrial DNA content in embryo culture medium is significantly associated with human embryo fragmentation.

PubMed

Stigliani, S; Anserini, P; Venturini, P L; Scaruffi, P

2013-10-01

Is the amount of cell-free DNA released by human embryos into culture medium correlated with embryo morphological features? The mitochondrial DNA (mtDNA) content of culture medium is significantly associated with the fragmentation rate on Days 2 and 3 of embryo development, whether the oocyte came from women ≤ 35 or >35 years old. Cellular fragmentation is often utilized as one of the morphological parameters for embryo quality assessment. The amount of cellular fragments is considered to be an important morphological parameter for embryo implantation potential. It has been hypothesized that fragments are apoptotic bodies or anuclear cytoplasmatic pieces of blastomeres, although no definitive conclusion has been drawn about their pathogenesis. Human fertilized oocytes were individually cultured from Day 1 to Days 2 and 3. A total of 800 samples (166 spent media from Day 2 and 634 from Day 3) were enrolled into the present study. Double-stranded DNA (dsDNA) was quantified in 800 spent embryo culture media by Pico Green dye fluorescence assay. After DNA purification, genomic DNA (gDNA) and mtDNA were profiled by specific quantitative PCR. Statistical analyses defined correlations among DNA contents, embryo morphology and maternal age. Different independent tests confirmed the presence of DNA into embryo culture medium and, for the first time, we demonstrate that both gDNA and mtDNA are detectable in the secretome. The amount of DNA is larger in embryos with bad quality cleavage compared with high-grade embryos, suggesting that the DNA profile of culture medium is an objective marker for embryo quality assessment. In particular, DNA profiles are significantly associated with fragmentation feature (total dsDNA: P = 0.0010; mtDNA; P = 0.0247) and advanced maternal age. It is necessary to establish whether DNA profiling of spent embryo culture medium is a robust onsite test that can improve the prediction of blastulation, implantation and/or pregnancy rate. The approach we are proposing may provide a novel, non-invasive, objective tool for embryo quality grading. The correlation between a high mtDNA concentration and the fragmentation rate of embryos is suggestive that fragments are mainly anuclear cytoplasmatic debris arising during cleavage. Therefore, blastomere shaping as an early event during in vitro development may play a homeostatic role and be related to embryo competence. This project was funded by Merck Serono (Grant for Fertility Innovation 2011). The sponsor had no role in study design, data collection, data analysis, data interpretation and writing of the paper. Authors declare no conflicts of interest. ClinicalTrials.gov Identifier: NCT01397136.

Insulin-like growth factor-1 protects preimplantation embryos from anti-developmental actions of menadione.

PubMed

Moss, James I; Pontes, Eduardo; Hansen, Peter James

2009-11-01

Menadione is a naphthoquinone used as a vitamin K source in animal feed that can generate reactive oxygen species (ROS) and cause apoptosis. Here, we examined whether menadione reduces development of preimplantation bovine embryos in a ROS-dependent process and tested the hypothesis that actions of menadione would be reduced by insulin-like growth factor-1 (IGF-1). Menadione caused a concentration-dependent decrease in the proportion of embryos that became blastocysts. All concentrations tested (1, 2.5, and 5.0 microM) inhibited development. Treatment with 100 ng/ml IGF-1 reduced the magnitude of the anti-developmental effects of the two lowest menadione concentrations. Menadione also caused a concentration-dependent increase in the percent of cells positive for the TUNEL reaction. The response was lower for IGF-1-treated embryos. The effects of menadione were mediated by ROS because (1) the anti-developmental effect of menadione was blocked by the antioxidants dithiothreitol and Trolox and (2) menadione caused an increase in ROS generation. Treatment with IGF-1 did not reduce ROS formation in menadione-treated embryos. In conclusion, concentrations of menadione as low as 1.0 muM can compromise development of bovine preimplantation embryos to the blastocyst stage of development in a ROS-dependent mechanism. Anti-developmental actions of menadione can be blocked by IGF-1 through effects downstream of ROS generation.

Laminarin improves developmental competence of porcine early stage embryos by inhibiting oxidative stress.

PubMed

Jiang, Hao; Liang, Shuang; Yao, Xue-Rui; Jin, Yong-Xun; Shen, Xing-Hui; Yuan, Bao; Zhang, Jia-Bao; Kim, Nam-Hyung

2018-04-23

Laminarin (LMA), a β-glucan mixture with good biocompatibility, improves the growth performance and immune response when used as food additives and nutraceuticals. The aim of the present research was to explore the effects of LMA on porcine early stage embryo development, as well as the underlying mechanisms. The results showed that the developmental competence of porcine early stage embryos was dramatically improved after LMA supplementation during the in vitro culture period. The presence of 20 μg/mL LMA during the in vitro culture period significantly improved cleavage rate, blastocyst formation rates, hatching rate, and total cell number in the blastocyst compared to that in the control group. Notably, LMA attenuated the intracellular reactive oxygen species generation induced by H 2 O 2 . Furthermore, LMA not only increased intracellular glutathione levels, but also ameliorated mitochondrial membrane potential. In addition, the expression of a zygotic genome activation related gene (YAP1), pluripotency-related genes (OCT4, NANOG, and SOX2), and hatching-related genes (COX2, GATA4, and ITGA5) were up-regulated following LMA supplementation during porcine early stage embryo development. These results demonstrate that LMA has beneficial effects on the development of porcine early stage embryos via regulation of oxidative stress. This evidence provides a novel method for embryo development improvement associated with exposure to LMA. Copyright © 2018 Elsevier Inc. All rights reserved.

The effects of levetiracetam on neural tube development in the early stage of chick embryos.

PubMed

Guvenc, Yahya; Dalgic, Ali; Billur, Deniz; Karaoglu, Derya; Aydin, Sevim; Daglioglu, Ergun; Ozdol, Cagatay; Nacar, Osman Arikan; Yildirim, Ali Erdem; Belen, Deniz

2013-01-01

This study aimed to investigate the effects of a new generation antiepileptic agent, levetiracetam, on the neural tube development in a chick embryo model that corresponds to the first month of vertebral development in mammals. Forty-five Atabey® breed fertilized chicken eggs with no specific pathogens were randomly divided into 5 groups. All of the eggs were incubated at 37.8±2°C and 60±5 % relative humidity in an incubator. Group A was control group. The other eggs were applied physiological saline and drugs at a volume of 10 μL by the in ovo method at the 28th hour of the incubation period. Group B was given distilled water; Group C, physiological saline; Group D, Levetiracetam (L8668) at a dose equivalent to the treatment dose for humans (10 mg/ kg), and Group E, Levetiracetam (L8668) at a dose of 10 times the treatment dose. The embryos in all of the groups were removed from the shells at the 48th hour and morphologically and histologically evaluated. Of the 45 embryos incubated, neural tubes of 41 were closed and the embryos displayed normal development. Levetiracetam, at a dose equivalent to human treatment dose and 10 times the treatment dose, was shown not to cause neural tube defects in chick embryos.

Caspase activity and expression of cell death genes during development of human preimplantation embryos.

PubMed

Spanos, S; Rice, S; Karagiannis, P; Taylor, D; Becker, D L; Winston, R M L; Hardy, K

2002-09-01

It has been observed that apoptosis occurs in human blastocysts. In other types of cell, the characteristic morphological changes seen in apoptotic cells are executed by caspases, which are regulated by the BCL-2 family of proteins. This study investigated whether these components of the apoptotic cascade are present throughout human preimplantation development. Developing and arrested two pronucleate embryos at all stages were incubated with a fluorescently tagged caspase inhibitor that binds only to active caspases, fixed, counterstained with 4,6-diamidino-2-phenylindole (DAPI) to assess nuclear morphology and examined using confocal microscopy. Active caspases were detected only after compaction, at the morula and blastocyst stages, and were frequently associated with apoptotic nuclei. Occasional labelling was seen in arrested embryos. Expression of proapoptotic BAX and BAD and anti-apoptotic BCL-2 was examined in single embryos using RT-PCR and immunohistochemistry. BAX and BCL-2 mRNAs were expressed throughout development, whereas BAD mRNA was expressed mainly after compaction. Simultaneous expression of BAX and BCL-2 proteins within individual embryos was confirmed using immunohistochemistry. The onset of caspase activity and BAD expression after compaction correlates with the previously reported appearance of apoptotic nuclei. As in other types of cell, human embryos express common molecular components of the apoptotic cascade, although apoptosis appears to be suppressed before compaction and differentiation.

Biopsy of embryos produced by in vitro fertilization affects development in C57BL/6 mouse strain

PubMed Central

Sugawara, Atsushi; Ward, Monika A.

2012-01-01

Preimplantation genetic diagnosis (PGD) is considered highly successful in respect to its accuracy in detecting genetic anomalies but the effects of embryo biopsy on embryonic/fetal growth and development are less known, particularly in conjunction with in vitro fertilization (IVF). Here, we compared biopsied (B) and non-biopsied (NB) mouse embryos for their developmental competence. Embryos C57BL/6 (B6) and B6D2F2 (F2) generated by IVF were subjected to single blastomere biopsy at the 4-cell stage, and were either cultured for 120 h and subjected to differential inner cell mass (ICM) and trophoblast (T) staining, or were transferred into the uterine tubes of surrogate mothers after 72 h of culture, to examine their pre- and post-implantation development, respectively. Non-biopsied embryos from the same IVF cohorts served as controls. Embryo biopsy negatively affected preimplantation development to blastocyst in C57BL/6 (69 vs 79%, P<0.01) but not in B6D2F1 mice (89 vs 91%, P=NS). Although B6 embryos had lower total cell number than F2 (B6: 47 and 61 vs. F1: 53 and 70; B and NB, respectively, P<0.05) there were no differences between B and NB blastocysts in %ICM (B6: 19.8 vs 19.8; F2: 20.9 vs 20.4, P=NS) and ICM:T ratio (B6: 4.7 vs 4.7; F2: 4.4 vs. 4.7) in both mouse strains. Post-implantation development to live fetuses of B embryos as compared to NB counterparts was impaired in C57BL/6 (6 vs 18%, P<0.001) but not in B6D2F1 mice (26 vs 35%, P=NS). We conclude that blastomere biopsy impairs embryonic/fetal development in mice known to be sensitive to in vitro culture and manipulations. Such mice model infertile couples with poor quality gametes seeking help in assisted reproduction technologies (ART) clinics. PMID:23174776

The Molecular Basis of Development.

ERIC Educational Resources Information Center

Gehring, Walter J.

1985-01-01

Basic architecture of embryo development appears to be under homeobox control (a short stretch of DNA). Outlines research on this genetic segment in fruit flies which led to identification of this control on the embryo's spatial organization. Indicates that molecular mechanisms underlying development may be much more universal than previously…

Inter- and intra-specific differences in the formation of O-xylosyl derivatives of zeatin and dihydrozeatin in Phaseolus embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mok, D.W.S.; Mok, M.C.

1987-08-01

The metabolism of /sup 14/C-zeatin was examined in embryos of P. coccineus cvs. Scarlet Runner (SR) and Desiree (Des). The O-xylosyl derivatives of zeatin and ribosylzeatin previously isolated from P. vulgaris embryos were found in both cultivars. In addition, two new metabolites were isolated from SR embryos and were identified by enzymatic degradation and GC-MS analyses as O-xylosyldihydrozeatin and its ribonucleaside. O-xylosylation of zeatin was also detected in P. acutifolius, but not in P. lunatus embryos. Both the formation of O-xylosyl derivatives and side chain reduction seem to be genotype specific. Moreover, they are most pronounced at early stages ofmore » embryo development.« less

Embryo transfer day does not affect the initial maternal serum β-hCG levels: A retrospective cohort study.

PubMed

Dahiya, Mona; Rupani, Karishma; Yu, Su Ling; Fook-Chong, Stephanie M C; Siew Fui, Diana Chia; Rajesh, Hemashree

2017-05-01

The aim of this study is to compare the serum β-hCG values post transfer of a cleavage stage embryo versus a blastocyst stage embryo at equal time intervals post oocyte retrieval (OR) in clinically pregnant patients, and to ascertain a β-hCG value to predict pregnancy outcomes. This is a retrospective cohort study of 560 women with clinical pregnancy who underwent an embryo transfer performed at either the cleavage stage or the blastocyst stage of embryo development between January 2003 and June 2014 at the Center for Assisted Reproduction (CARE), Singapore General Hospital. The serum β-hCG level was measured on day 17 post OR. The β-hCG values were not significantly different in the cleavage stage versus the blastocyst stage embryos (mean±SD: 387±486IU/L D3 vs. 352±268IU/L D5, p=0.96, median value 297 in both groups). Our study suggests that the initial maternal serum β-hCG values were not affected by the day of transfer of the embryos since assessing the β-hCG at equivalent points after transfer should not lead to a significant difference assuming the progress and development of the embryos occurred as expected. Copyright © 2017 Elsevier B.V. All rights reserved.

Interfacing Lab-on-a-Chip Embryo Technology with High-Definition Imaging Cytometry.

PubMed

Zhu, Feng; Hall, Christopher J; Crosier, Philip S; Wlodkowic, Donald

2015-08-01

To spearhead deployment of zebrafish embryo biotests in large-scale drug discovery studies, automated platforms are needed to integrate embryo in-test positioning and immobilization (suitable for high-content imaging) with fluidic modules for continuous drug and medium delivery under microperfusion to developing embryos. In this work, we present an innovative design of a high-throughput three-dimensional (3D) microfluidic chip-based device for automated immobilization and culture and time-lapse imaging of developing zebrafish embryos under continuous microperfusion. The 3D Lab-on-a-Chip array was fabricated in poly(methyl methacrylate) (PMMA) transparent thermoplastic using infrared laser micromachining, while the off-chip interfaces were fabricated using additive manufacturing processes (fused deposition modelling and stereolithography). The system's design facilitated rapid loading and immobilization of a large number of embryos in predefined clusters of traps during continuous microperfusion of drugs/toxins. It was conceptually designed to seamlessly interface with both upright and inverted fluorescent imaging systems and also to directly interface with conventional microtiter plate readers that accept 96-well plates. Compared with the conventional Petri dish assays, the chip-based bioassay was much more convenient and efficient as only small amounts of drug solutions were required for the whole perfusion system running continuously over 72 h. Embryos were spatially separated in the traps that assisted tracing single embryos, preventing interembryo contamination and improving imaging accessibility.

The behavioural and physiological strategies of bird and reptile embryos in response to unpredictable variation in nest temperature.

PubMed

Du, Wei-Guo; Shine, Richard

2015-02-01

Temperature profoundly affects the rate and trajectory of embryonic development, and thermal extremes can be fatal. In viviparous species, maternal behaviour and physiology can buffer the embryo from thermal fluctuations; but in oviparous animals (like most reptiles and all birds), an embryo is likely to encounter unpredictable periods when incubation temperatures are unfavourable. Thus, we might expect natural selection to have favoured traits that enable embryos to maintain development despite those fluctuations. Our review of recent research identifies three main routes that embryos use in this way. Extreme temperatures (i) can be avoided (e.g. by accelerating hatching, by moving within the egg, by cooling the egg by enhanced rates of evaporation, or by hysteresis in rates of heating versus cooling); (ii) can be tolerated (e.g. by entering diapause, by producing heat-shock proteins, or by changing oxygen use); or (iii) the embryo can adjust its physiology and/or developmental trajectory in ways that reduce the fitness penalties of unfavourable thermal conditions (e.g. by acclimating, by exploiting brief windows of favourable conditions, or by producing the hatchling phenotype best suited to those incubation conditions). Embryos are not simply passive victims of ambient conditions. Like free-living stages of the life cycle, embryos exhibit behavioural and physiological plasticity that enables them to deal with unpredictable abiotic challenges. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

The frequency of clinical pregnancy and implantation rate after cultivation of embryos in a medium with granulocyte macrophage colony-stimulating factor (GM-CSF) in patients with preceding failed attempts of ART.

PubMed

Tevkin, S; Lokshin, V; Shishimorova, M; Polumiskov, V

2014-10-01

The application in IVF practice of modern techniques can improve positive outcome of each cycle in the assisted reproductive technology (ART) programs and the effectiveness of treatment as a whole. There are embryos in the female reproductive tract in physiological medium which contain various cytokines and growth factors. It plays an important role in the regulation of normal embryonic development, improve implantation and subsequently optimizing the development of the fetus and the placenta. Granulocyte macrophage colony-stimulating factor (GM-CSF is one of the cytokines playing an important role in reproductive function. Addition of recombinant GM-CSF to the culture medium can makes closer human embryos culture to in vivo conditions and improve the efficacy ART cycles. The analysis of culture embryos in EmbryoGen medium has shown that fertilization rate embryo culture and transfer to patients with previous unsuccessful attempts increases clinical pregnancy rate compared to the control group 39.1 versus 27.8%, respectively. It is noted that the implantation rate (on 7 weeks' gestation) and progressive clinical pregnancy rate (on 12 weeks' gestation) were significantly higher in group embryos culture in EmbryoGen medium compared to standard combination of medium (ISM1+VA), and were 20.4 and 17.4% versus 11.6 and 9.1%, respectively.

In vitro and in vivo survival of bisected sheep embryos derived from frozen-thawed unsorted, and frozen-thawed sex-sorted and refrozen-thawed ram spermatozoa.

PubMed

Morton, Katherine M; Rowe, Anthony M; Chis Maxwell, W M; Evans, Gareth

2006-04-15

Ovine IVP embryos were derived from frozen-thawed unsorted and frozen-thawed sex-sorted spermatozoa that had been refrozen and thawed. The embryos were bisected and cultured in vitro, or transferred to recipient ewes to determine their survival in vitro and in vivo. Oocyte progression to the blastocyst stage was similar for unsorted (97/232, 41.8%) and sex-sorted spermatozoa (113/286, 39.5%; P > 0.05). Embryo survival in vitro post-bisection was similar for demi-embryos derived from unsorted and sex-sorted sperm, and embryos bisected at the blastocyst and expanded blastocyst stage (P > 0.05). A higher proportion of recipient ewes were pregnant at Day 63 after transfer of two intact embryos derived from unsorted (17/21, 80.9%) than two demi-embryos derived from unsorted (5/15, 33.3%) or sex-sorted spermatozoa (7/17, 41.2%). The number of fetuses per original embryo at Day 63 did not differ among groups (unsorted intact: 23/42, 54.8%; unsorted demi: 7/15, 46.7%; sex-sorted demi: 10/17, 58.8%) and twin pregnancies were observed in all groups. Embryo survival to term was high, and was not significantly different among intact (unsorted: 22/42, 52.4%) and demi-embryos (unsorted: 4/15, 26.7%; sex-sorted spermatozoa: 7/17, 41.2%; P > 0.05). Dizygotic twins (n = 6 sets) were born after the transfer of two intact embryos derived from unsorted spermatozoa, but only singleton lambs resulted from the transfer of demi-embryos. In conclusion, bisected IVP embryos successfully developed into morphologically normal lambs. However, embryo survival to term was neither increased nor decreased by embryo bisection.

Inter-laboratory agreement on embryo classification and clinical decision: Conventional morphological assessment vs. time lapse.

PubMed

Martínez-Granados, Luis; Serrano, María; González-Utor, Antonio; Ortíz, Nereyda; Badajoz, Vicente; Olaya, Enrique; Prados, Nicolás; Boada, Montse; Castilla, Jose A

2017-01-01

The aim of this study is to determine inter-laboratory variability on embryo assessment using time-lapse platform and conventional morphological assessment. This study compares the data obtained from a pilot study of external quality control (EQC) of time lapse, performed in 2014, with the classical EQC of the Spanish Society for the Study of Reproductive Biology (ASEBIR) performed in 2013 and 2014. In total, 24 laboratories (8 using EmbryoScope™, 15 using Primo Vision™ and one with both platforms) took part in the pilot study. The clinics that used EmbryoScope™ analysed 31 embryos and those using Primo Vision™ analysed 35. The classical EQC was implemented by 39 clinics, based on an analysis of 25 embryos per year. Both groups were required to evaluate various qualitative morphological variables (cell fragmentation, the presence of vacuoles, blastomere asymmetry and multinucleation), to classify the embryos in accordance with ASEBIR criteria and to stipulate the clinical decision taken. In the EQC time-lapse pilot study, the groups were asked to determine, as well as the above characteristics, the embryo development times, the number, opposition and size of pronuclei, the direct division of 1 into 3 cells and/or of 3 into 5 cells and false divisions. The degree of agreement was determined by calculating the intra-class correlation coefficients and the coefficient of variation for the quantitative variables and the Gwet index for the qualitative variables. For both EmbryoScope™ and Primo Vision™, two periods of greater inter-laboratory variability were observed in the times of embryo development events. One peak of variability was recorded among the laboratories addressing the first embryo events (extrusion of the second polar body and the appearance of pronuclei); the second peak took place between the times corresponding to the 8-cell and morula stages. In most of the qualitative variables analysed regarding embryo development, there was almost-perfect inter-laboratory agreement among conventional morphological assessment (CMA), EmbryoScope™ and Primo Vision™, except for false divisions, vacuoles and asymmetry (users of all methods) and multinucleation (users of Primo Vision™), where the degree of agreement was lower. The inter-laboratory agreement on embryo classification according to the ASEBIR criteria was moderate-substantial (Gwet 0.41-0.80) for the laboratories using CMA and EmbryoScope™, and fair-moderate (Gwet 0.21-0.60) for those using Primo Vision™. The inter-laboratory agreement for clinical decision was moderate (Gwet 0.41-0.60) on day 5 for CMA users and almost perfect (Gwet 0.81-1) for time-lapse users. In conclusion, time-lapse technology does not improve inter-laboratory agreement on embryo classification or the analysis of each morphological variable. Moreover, depending on the time-lapse platform used, inter-laboratory agreement may be lower than that obtained by CMA. However, inter-laboratory agreement on clinical decisions is improved with the use of time lapse, regardless of the platform used.

Inter-laboratory agreement on embryo classification and clinical decision: Conventional morphological assessment vs. time lapse

PubMed Central

Serrano, María; González-Utor, Antonio; Ortíz, Nereyda; Badajoz, Vicente; Olaya, Enrique; Prados, Nicolás; Boada, Montse; Castilla, Jose A.

2017-01-01

The aim of this study is to determine inter-laboratory variability on embryo assessment using time-lapse platform and conventional morphological assessment. This study compares the data obtained from a pilot study of external quality control (EQC) of time lapse, performed in 2014, with the classical EQC of the Spanish Society for the Study of Reproductive Biology (ASEBIR) performed in 2013 and 2014. In total, 24 laboratories (8 using EmbryoScope™, 15 using Primo Vision™ and one with both platforms) took part in the pilot study. The clinics that used EmbryoScope™ analysed 31 embryos and those using Primo Vision™ analysed 35. The classical EQC was implemented by 39 clinics, based on an analysis of 25 embryos per year. Both groups were required to evaluate various qualitative morphological variables (cell fragmentation, the presence of vacuoles, blastomere asymmetry and multinucleation), to classify the embryos in accordance with ASEBIR criteria and to stipulate the clinical decision taken. In the EQC time-lapse pilot study, the groups were asked to determine, as well as the above characteristics, the embryo development times, the number, opposition and size of pronuclei, the direct division of 1 into 3 cells and/or of 3 into 5 cells and false divisions. The degree of agreement was determined by calculating the intra-class correlation coefficients and the coefficient of variation for the quantitative variables and the Gwet index for the qualitative variables. For both EmbryoScope™ and Primo Vision™, two periods of greater inter-laboratory variability were observed in the times of embryo development events. One peak of variability was recorded among the laboratories addressing the first embryo events (extrusion of the second polar body and the appearance of pronuclei); the second peak took place between the times corresponding to the 8-cell and morula stages. In most of the qualitative variables analysed regarding embryo development, there was almost-perfect inter-laboratory agreement among conventional morphological assessment (CMA), EmbryoScope™ and Primo Vision™, except for false divisions, vacuoles and asymmetry (users of all methods) and multinucleation (users of Primo Vision™), where the degree of agreement was lower. The inter-laboratory agreement on embryo classification according to the ASEBIR criteria was moderate-substantial (Gwet 0.41–0.80) for the laboratories using CMA and EmbryoScope™, and fair-moderate (Gwet 0.21–0.60) for those using Primo Vision™. The inter-laboratory agreement for clinical decision was moderate (Gwet 0.41–0.60) on day 5 for CMA users and almost perfect (Gwet 0.81–1) for time-lapse users. In conclusion, time-lapse technology does not improve inter-laboratory agreement on embryo classification or the analysis of each morphological variable. Moreover, depending on the time-lapse platform used, inter-laboratory agreement may be lower than that obtained by CMA. However, inter-laboratory agreement on clinical decisions is improved with the use of time lapse, regardless of the platform used. PMID:28841654

Differences in gene expression profiles between human preimplantation embryos cultured in two different IVF culture media.

PubMed

Kleijkers, Sander H M; Eijssen, Lars M T; Coonen, Edith; Derhaag, Josien G; Mantikou, Eleni; Jonker, Martijs J; Mastenbroek, Sebastiaan; Repping, Sjoerd; Evers, Johannes L H; Dumoulin, John C M; van Montfoort, Aafke P A

2015-10-01

Is gene expression in human preimplantation embryos affected by the medium used for embryo culture in vitro during an IVF treatment? Six days of in vitro culture of human preimplantation embryos resulted in medium-dependent differences in expression level of genes involved in apoptosis, protein degradation, metabolism and cell-cycle regulation. Several human studies have shown an effect of culture medium on embryo development, pregnancy outcome and birthweight. However, the underlying mechanisms in human embryos are still unknown. In animal models of human development, it has been demonstrated that culture of preimplantation embryos in vitro affects gene expression. In humans, it has been found that culture medium affects gene expression of cryopreserved embryos that, after thawing, were cultured in two different media for 2 more days. In a multicenter trial, women were randomly assigned to two culture medium groups [G5 and human tubal fluid (HTF)]. Data on embryonic development were collected for all embryos. In one center, embryos originating from two pronuclei (2PN) zygotes that were not selected for transfer or cryopreservation on Day 2 or 3 because of lower morphological quality, were cultured until Day 6 and used in this study, if couples consented. Ten blastocysts each from the G5 and HTF study groups, matched for fertilization method, maternal age and blastocyst quality, were selected and their mRNA was isolated and amplified. Embryos were examined individually for genome-wide gene expression using Agilent microarrays and PathVisio was used to identify the pathways that showed a culture medium-dependent activity. Expression of 951 genes differed significantly (P < 0.01) between the G5 and HTF groups. Eighteen pathways, involved in apoptosis, metabolism, protein processing and cell-cycle regulation, showed a significant overrepresentation of differentially expressed genes. The DNA replication, G1 to S cell-cycle control and oxidative phosphorylation pathways were up-regulated in the G5 group compared with the HTF group. This is in agreement with the morphological assessment of the 1527 embryos (originating from 2PN zygotes), which showed that embryos consisted of more cells on Day 2 (3.73 ± 1.30 versus 3.40 ± 1.35, P < 0.001) and Day 3 (7.00 ± 2.41 versus 5.84 ± 2.36, P < 0.001) in the G5 group when compared with the HTF group. Furthermore, the implantation rate was significantly higher in the G5 group compared with the HTF group (26.7% versus 14.7%, P = 0.002) after transfer on the second or the third day after fertilization. Despite careful matching of the embryos, it cannot be excluded that the differences observed between the study groups are caused by factors that we did not investigate. Extrapolation of these results to embryos used for transfer demands caution as in the present study embryos that were not selected for either embryo transfer or cryopreservation have been used for the culture experiment until Day 6. This study shows that gene expression in human preimplantation embryos is altered by the culture medium used during IVF treatment and provides insight into the biological pathways that are affected. Whether these changes in gene expression have any long-term effects on children born after IVF remains unknown. However, it is possible that early adaptations of the preimplantation embryo to its environment persist during fetal and post-natal development. No funding and no competing interests declared. Not applicable. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Regulative recovery in the sea urchin embryo and the stabilizing role of fail-safe gene network wiring

PubMed Central

Smith, Joel; Davidson, Eric H.

2009-01-01

Design features that ensure reproducible and invariant embryonic processes are major characteristics of current gene regulatory network models. New cis-regulatory studies on a gene regulatory network subcircuit activated early in the development of the sea urchin embryo reveal a sequence of encoded “fail-safe” regulatory devices. These ensure the maintenance of fate separation between skeletogenic and nonskeletogenic mesoderm lineages. An unexpected consequence of the network design revealed in the course of these experiments is that it enables the embryo to “recover” from regulatory interference that has catastrophic effects if this feature is disarmed. A reengineered regulatory system inserted into the embryo was used to prove how this system operates in vivo. Genomically encoded backup control circuitry thus provides the mechanism underlying a specific example of the regulative development for which the sea urchin embryo has long been famous. PMID:19822764

Eye and heart morphogenesis are dependent on melatonin signaling in chick embryos.

PubMed

Nogueira, Renato C; Sampaio, Lucia de Fatima S

2017-10-15

Calmodulin is vital for chick embryos morphogenesis in the incubation time 48-66 h when the rudimentary C-shaped heart attains an S-shaped pattern and the optic vesicles develop into optic cups. Melatonin is in the extraembryonic yolk sac of the avian egg; melatonin binds calmodulin. The aim of this study was to investigate the function of melatonin in the formation of the chick embryo optic cups and S-shaped heart, by pharmacological methods and immunoassays. Mel1a melatonin receptor immunofluorescence was distributed in the optic cups and rudimentary hearts. We separated embryonated chicken eggs at 48 h of incubation into basal, control and drug-treated groups, with treatment applied in the egg air sac. At 66 h of incubation, embryos were excised from the eggs and analyzed. Embryos from the basal, control (distilled water), melatonin and 6-chloromelatonin (melatonin receptor agonist) groups had regular optic cups and an S-shaped heart, while those from the calmidazolium (calmodulin inhibitor) group did not. Embryos from the luzindole (melatonin receptor antagonist) and prazosin (Mel1c melatonin receptor antagonist) groups did not have regular optic cups. Embryos from the 4-P-PDOT (Mel1b melatonin receptor antagonist) group did not have an S-shaped heart. Previous application of the melatonin, 6-chloromelatonin or forskolin (adenylate cyclase enhancer) prevented the abnormal appearance of chick embryos from the calmidazolium, luzindole, prazosin and 4-P-PDOT groups. However, 6-chloromelatonin and forskolin only partially prevented the development of defective eye cups in embryos from the calmidazolium group. The results suggested that melatonin modulates chick embryo morphogenesis via calmodulin and membrane receptors. © 2017. Published by The Company of Biologists Ltd.

Vitrification-based cryopreservation of Drosophila embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schreuders, P.D.; Mazur, P.

1994-12-31

Currently, over 30,000 strains of Drosophila melanogaster are maintained by geneticists through regular transfer of breeding stocks. A more cost effective solution is to cryopreserve their embryos. Cooling and warming rates >10,000{degrees}C/min. are required to prevent chilling injury. To avoid the lethal intracellular ice normally produced at such high cooling rates, it is necessary to use {ge}50% (w/w) concentrations of glass-inducing solutes to vitrify the embryos. Differential scanning calorimetry (DSC) is used to develop and evaluate ethylene glycol and polyvinyl pyrrolidone based vitrification solutions. The resulting solution consists of 8.5M ethylene glycol + 10% polyvinylpyrrolidone in D-20 Drosophila culture medium.more » A two stage method is used for the introduction and concentration of these solutes within the embryo. The method reduces the exposure time to the solution and, consequently, reduces toxicity. Both DSC and freezing experiments suggest that, while twelve-hour embryos will vitrify using cooling rates >200{degrees}C/min., they will devitrify and be killed with even moderately rapid warming rates of {approximately}1,900{degrees}C/min. Very rapid warming ({approximately}100,000{degrees}C/min.) results in variable numbers of successfully cryopreserved embryos. This sensitivity to warming rite is typical of devitrification. The variability in survival is reduced using embryos of a precisely determined embryonic stage. The vitrification of the older, fifteen-hour, embryos yields an optimized hatching rate of 68%, with 35 - 40% of the resulting larvae developing to normal adults. This Success rite in embryos of this age may reflect a reduced sensitivity to limited devitrification or a more even distribution of the ethylene glycol within the embryo.« less

Evaluating the zebrafish embryo toxicity test for pesticide hazard screening.

PubMed

Glaberman, Scott; Padilla, Stephanie; Barron, Mace G

2017-05-01

Given the numerous chemicals used in society, it is critical to develop tools for accurate and efficient evaluation of potential risks to human and ecological receptors. Fish embryo acute toxicity tests are 1 tool that has been shown to be highly predictive of standard, more resource-intensive, juvenile fish acute toxicity tests. However, there is also evidence that fish embryos are less sensitive than juvenile fish for certain types of chemicals, including neurotoxicants. The utility of fish embryos for pesticide hazard assessment was investigated by comparing published zebrafish embryo toxicity data from pesticides with median lethal concentration 50% (LC50) data for juveniles of 3 commonly tested fish species: rainbow trout, bluegill sunfish, and sheepshead minnow. A poor, albeit significant, relationship (r 2  = 0.28; p < 0.05) was found between zebrafish embryo and juvenile fish toxicity when pesticides were considered as a single group, but a much better relationship (r 2  = 0.64; p < 0.05) when pesticide mode of action was factored into an analysis of covariance. This discrepancy is partly explained by the large number of neurotoxic pesticides in the dataset, supporting previous findings that commonly used fish embryo toxicity test endpoints are particularly insensitive to neurotoxicants. These results indicate that it is still premature to replace juvenile fish toxicity tests with embryo-based tests such as the Organisation for Economic Co-operation and Development Fish Embryo Acute Toxicity Test for routine pesticide hazard assessment, although embryo testing could be used with other screening tools for testing prioritization. Environ Toxicol Chem 2017;36:1221-1226. © 2016 SETAC. © 2016 SETAC.

Use of laboratory studies to develop a dispersal model for Missouri River pallid sturgeon early life intervals

USGS Publications Warehouse

Kynard, B.; Parker, E.; Pugh, D.; Parker, T.

2007-01-01

Understanding the drift dynamics of pallid sturgeon (Scaphirhynchus albus) early life intervals is critical to evaluating damming effects on sturgeons. However, studying dispersal behavior is difficult in rivers. In stream tanks, we studied the effect of velocity on dispersal and holding ability, estimated swimming height, and used the data to estimate drift distance of pallid sturgeon. Dispersal was by days 0-10 embryos until fish developed into larvae on day 11 after 200 CTU (daily cumulative temperature units). Embryos in tanks with a mean channel velocity of 30.1 cm s-1 and a side eddy could not hold position in the eddy, so current controlled dispersal. Late embryos (days 6-10 fish) dispersed more passes per hour than early embryos (days 0-5 fish) and held position in side eddies when channel velocities were 17.3 cm s-1 or 21.1 cm s-1. Day and night swim-up and drift by embryos is an effective adaptation to disperse fish in channel flow and return fish from side eddies to the channel. Early embryos swam <0.50 cm above the bottom and late embryos swam higher (mean, 90 cm). A passive drift model using a near bottom velocity of 32 cm s-1 predicted that embryos dispersing for 11 days in channel flow would travel 304 km. Embryos spawned at Fort Peck Dam, Missouri River, must stop dispersal in <330 km or enter Lake Sakakawea, where survival is likely poor. The model suggests there may be a mismatch between embryo dispersal distance and location of suitable rearing habitat. This situation may be common for pallid sturgeon in dammed rivers. ?? 2007 Blackwell Verlag.

The evolution of porcine embryo in vitro production.

PubMed

Grupen, Christopher G

2014-01-01

The in vitro production of porcine embryos has presented numerous challenges to researchers over the past four decades. Some of the problems encountered were specific to porcine gametes and embryos and needed the concerted efforts of many to overcome. Gradually, porcine embryo in vitro production systems became more reliable and acceptable rates of blastocyst formation were achieved. Despite the significant improvements, the problem of polyspermic fertilization has still not been adequately resolved and the embryo in vitro culture conditions are still considered to be suboptimal. Whereas early studies focused on increasing our understanding of the reproductive processes involved, the technology evolved to the point where in vitro-matured oocytes and in vitro-produced embryos could be used as research material for developing associated reproductive technologies, such as SCNT and embryo cryopreservation. Today, the in vitro procedures used to mature oocytes and culture embryos are integral to the production of transgenic pigs by SCNT. This review discusses the major achievements, advances, and knowledge gained from porcine embryo in vitro production studies and highlights the future research perspectives of this important technology. Copyright © 2014 Elsevier Inc. All rights reserved.

Pre-persons, commodities or cyborgs: the legal construction and representation of the embryo.

PubMed

Fox, M

2000-01-01

This paper explores how embryos have been represented in law. It argues that two main models have underpinned legal discourse concerning the embryo. One discourse, which has become increasingly prevalent, views embryos as legal subjects or persons. Such representations are facilitated by technological developments such as ultrasound imaging. In addition to influencing Parliamentary debate prior to the passage of the Human Fertilisation and Embryology Act 1990, images of embryos as persons feature prominently in popular culture, including advertising and films, and this discourse came to the fore in the 'orphaned embryo' debate in 1996. The main opposing discourse dismisses embryos as commodifiable objects, which fits with a trend towards legal recognition that reproductive materials such as sperm may be classified as property which may be donated or sold. In the case of cryopreserved embryos these competing perspectives have resulted in litigation over the status of frozen embryos. In this paper I argue that it might be productive to shift the debate from this polarised dispute over whether embryos matter or not, whether they are pre-persons or commodities. Instead, I suggest that we should attempt to locate them in a biotechnological milieu, where cyborg metaphors may be utilised, and questions of how we should treat embryos would be contextualized alongside our response to other cyborgs.

Developmental localization and the role of hydroxyproline rich glycoproteins during somatic embryogenesis of banana (Musa spp. AAA)

PubMed Central

2011-01-01

Background Hydroxyproline rich glycoproteins (HRGPs) are implicated to have a role in many aspects of plant growth and development but there is limited knowledge about their localization and function during somatic embryogenesis of higher plants. In this study, the localization and function of hydroxyproline rich glycoproteins in embryogenic cells (ECs) and somatic embryos of banana were investigated by using immunobloting and immunocytochemistry with monoclonal JIM11 and JIM20 antibodies as well as by treatment with 3,4-dehydro-L-proline (3,4-DHP, an inhibitor of extensin biosynthesis), and by immunomodulation with the JIM11 antibody. Results Immunofluorescence labelling of JIM11 and JIM20 hydroxyproline rich glycoprotein epitopes was relatively weak in non-embryogenic cells (NECs), mainly on the edge of small cell aggregates. On the other hand, hydroxyproline rich glycoprotein epitopes were found to be enriched in early embryogenic cells as well as in various developmental stages of somatic embryos. Embryogenic cells (ECs), proembryos and globular embryos showed strong labelling of hydroxyproline rich glycoprotein epitopes, especially in their cell walls and outer surface layer, so-called extracellular matrix (ECM). This hydroxyproline rich glycoprotein signal at embryo surfaces decreased and/or fully disappeared during later developmental stages (e.g. pear-shaped and cotyledonary stages) of embryos. In these later developmental embryogenic stages, however, new prominent hydroxyproline rich glycoprotein labelling appeared in tri-cellular junctions among parenchymatic cells inside these embryos. Overall immunofluorescence labelling of late stage embryos with JIM20 antibody was weaker than that of JIM11. Western blot analysis supported the above immunolocalization data. The treatment with 3,4-DHP inhibited the development of embryogenic cells and decreased the rate of embryo germination. Embryo-like structures, which developed after 3,4-DHP treatment showed aberrant non-compact epidermis with discontinuous ECM at the outer surface as well as much less immunolabelling with the JIM11 antibody. This treatment also decreased the plant regeneration capacity in embryogenic banana cultures. Finally, immunomodulation of surface hydroxyproline rich glycoproteins by co-culture of embryos with the JIM11 antibody resulted in a much lower germination capacity of these embryos. Conclusions These results suggest that hydroxyproline rich glycoproteins play an important developmental role, especially in the process of regeneration and germination of embryos during plant regeneration via somatic embryogenesis. Proper content and localization of hydroxyproline rich glycoproteins seem to be essential for the formation and regeneration of banana somatic embryos. PMID:21349190

Microfluidics for mammalian embryo culture and selection: where do we stand now?

PubMed

Le Gac, Séverine; Nordhoff, Verena

2017-04-01

The optimization of in-vitro culture conditions and the selection of the embryo(s) with the highest developmental competence are essential components in an ART program. Culture conditions are manifold and they underlie not always evidence-based research but also trends entering the IVF laboratory. At the moment, the idea of using sequential media according to the embryo requirements has been given up in favor of the use of single step media in an uninterrupted manner due to practical issues such as time-lapse incubators. The selection of the best embryo is performed using morphological and, recently, also morphokinetic criteria. In this review, we aim to demonstrate how the ART field may benefit from the use of microfluidic technology, with a particular focus on specific steps, namely the embryo in-vitro culture, embryo scoring and selection, and embryo cryopreservation. We first provide an overview of microfluidic and microfabricated devices, which have been developed for embryo culture, characterization of pre-implantation embryos (or in some instances a combination of both steps) and embryo cryopreservation. Building upon these existing platforms and the various capabilities offered by microfluidics, we discuss how this technology could provide integrated and automated systems, not only for real-time and multi-parametric monitoring of embryo development, but also for performing the entire ART procedure. Although microfluidic technology has been around for a couple of decades already, it has still not made its way into the clinics and IVF laboratories, which we discuss in terms of: (i) a lack of user-friendliness and automation of the microfluidic platforms, (ii) a lack of robust and convincing validation using human embryos and (iii) some psychological threshold for embryologists and practitioners to test and use microfluidic technology. In spite of these limitations, we envision that microfluidics is likely to have a significant impact in the field of ART, for fundamental research in the near future and, in the longer term, for providing a novel generation of clinical tools. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved.For Permissions, please email: journals.permissions@oup.com.

Turtle embryos move to optimal thermal environments within the egg.

PubMed

Zhao, Bo; Li, Teng; Shine, Richard; Du, Wei-Guo

2013-08-23

A recent study demonstrated that the embryos of soft-shelled turtles can reposition themselves within their eggs to exploit locally warm conditions. In this paper, we ask whether turtle embryos actively seek out optimal thermal environments for their development, as do post-hatching individuals. Specifically, (i) do reptile embryos move away from dangerously high temperatures as well as towards warm temperatures? and (ii) is such embryonic movement due to active thermoregulation, or (more simply) to passive embryonic repositioning caused by local heat-induced changes in viscosity of fluids within the egg? Our experiments with an emydid turtle (Chinemys reevesii) show that embryos avoid dangerously high temperatures by moving to cooler regions of the egg. The repositioning of embryos is an active rather than passive process: live embryos move towards a heat source, whereas dead ones do not. Overall, our results suggest that behavioural thermoregulation by turtle embryos is genuinely analogous to the thermoregulatory behaviour exhibited by post-hatching ectotherms.

Expanding Actin Rings Zipper the Mouse Embryo for Blastocyst Formation.

PubMed

Zenker, Jennifer; White, Melanie D; Gasnier, Maxime; Alvarez, Yanina D; Lim, Hui Yi Grace; Bissiere, Stephanie; Biro, Maté; Plachta, Nicolas

2018-04-19

Transformation from morula to blastocyst is a defining event of preimplantation embryo development. During this transition, the embryo must establish a paracellular permeability barrier to enable expansion of the blastocyst cavity. Here, using live imaging of mouse embryos, we reveal an actin-zippering mechanism driving this embryo sealing. Preceding blastocyst stage, a cortical F-actin ring assembles at the apical pole of the embryo's outer cells. The ring structure forms when cortical actin flows encounter a network of polar microtubules that exclude F-actin. Unlike stereotypical actin rings, the actin rings of the mouse embryo are not contractile, but instead, they expand to the cell-cell junctions. Here, they couple to the junctions by recruiting and stabilizing adherens and tight junction components. Coupling of the actin rings triggers localized myosin II accumulation, and it initiates a tension-dependent zippering mechanism along the junctions that is required to seal the embryo for blastocyst formation. Copyright © 2018 Elsevier Inc. All rights reserved.

Mouse model of chromosome mosaicism reveals lineage-specific depletion of aneuploid cells and normal developmental potential.

PubMed

Bolton, Helen; Graham, Sarah J L; Van der Aa, Niels; Kumar, Parveen; Theunis, Koen; Fernandez Gallardo, Elia; Voet, Thierry; Zernicka-Goetz, Magdalena

2016-03-29

Most human pre-implantation embryos are mosaics of euploid and aneuploid cells. To determine the fate of aneuploid cells and the developmental potential of mosaic embryos, here we generate a mouse model of chromosome mosaicism. By treating embryos with a spindle assembly checkpoint inhibitor during the four- to eight-cell division, we efficiently generate aneuploid cells, resulting in embryo death during peri-implantation development. Live-embryo imaging and single-cell tracking in chimeric embryos, containing aneuploid and euploid cells, reveal that the fate of aneuploid cells depends on lineage: aneuploid cells in the fetal lineage are eliminated by apoptosis, whereas those in the placental lineage show severe proliferative defects. Overall, the proportion of aneuploid cells is progressively depleted from the blastocyst stage onwards. Finally, we show that mosaic embryos have full developmental potential, provided they contain sufficient euploid cells, a finding of significance for the assessment of embryo vitality in the clinic.

Turtle embryos move to optimal thermal environments within the egg

PubMed Central

Zhao, Bo; Li, Teng; Shine, Richard; Du, Wei-Guo

2013-01-01

A recent study demonstrated that the embryos of soft-shelled turtles can reposition themselves within their eggs to exploit locally warm conditions. In this paper, we ask whether turtle embryos actively seek out optimal thermal environments for their development, as do post-hatching individuals. Specifically, (i) do reptile embryos move away from dangerously high temperatures as well as towards warm temperatures? and (ii) is such embryonic movement due to active thermoregulation, or (more simply) to passive embryonic repositioning caused by local heat-induced changes in viscosity of fluids within the egg? Our experiments with an emydid turtle (Chinemys reevesii) show that embryos avoid dangerously high temperatures by moving to cooler regions of the egg. The repositioning of embryos is an active rather than passive process: live embryos move towards a heat source, whereas dead ones do not. Overall, our results suggest that behavioural thermoregulation by turtle embryos is genuinely analogous to the thermoregulatory behaviour exhibited by post-hatching ectotherms. PMID:23760168

77 FR 25488 - Cooperative Research and Development Agreement: Federally Integrated Communications System

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-30

... Cooperative Research and Development Agreement (CRADA) with General Dynamics C4 Systems, Inc. to lab... operations of the Coast Guard's Rescue 21 system; (2) General Dynamics' capability to provide the significant... Development Agreement: Federally Integrated Communications System AGENCY: Coast Guard, DHS. ACTION: Notice of...

Assessment of cardiotoxicity and effects of malathion on the early development of zebrafish (Danio rerio) using computer vision for heart rate quantification.

PubMed

Simoneschi, Daniele; Simoneschi, Francesco; Todd, Nancy E

2014-06-01

Malathion, a common organophosphate insecticide, is a proven acetylcholinesterase inhibitor and is the most applied organophosphate insecticide in the United States. The use of zebrafish as a model to study the effects of pesticides on development is an innovative approach yielding relevant implications for determining the potential toxic effects of these pesticides on humans. In this study, a simple noninvasive technique was developed to investigate the cardiotoxicity of malathion on Danio rerio embryos, and to detect and quantify its effect on heart rate. Videos were recorded under a stereomicroscope and examined with our custom-made software (FishBeat) to determine the heart rate of the embryos. The pixel average intensity frequency (PI) of the videos was computed at its maximum probability to indicate the average number of heartbeats per second. Experimental observations successfully demonstrated that this method was able to detect the heart rate of zebrafish embryos as compared with manual stopwatch counting, with no significant difference. Embryos were treated acutely with increasing malathion concentrations (33.3 and 50 μg/mL malathion) at 52, 76, and 96 hpf. Embryos treated with 33.3 μg/mL malathion had significant bradycardia at 52 and 76 hpf, whereas embryos treated with 50 μg/mL malathion presented bradycardia at all hpf. These novel observations confirmed that malathion, acting as an acetylcholinesterase inhibitor, induced heartbeat irregularity in zebrafish embryos.

The progressive onset of cholinergic and adrenergic control of heart rate during development in the green iguana, Iguana iguana.

PubMed

Sartori, Marina R; Leite, Cleo A C; Abe, Augusto S; Crossley, Dane A; Taylor, Edwin W

2015-10-01

The autonomic control of heart rate was studied throughout development in embryos of the green iguana, Iguana iguana by applying receptor agonists and antagonists of the parasympathetic and sympathetic systems. Acetylcholine (Ach) slowed or stopped the heart and atropine antagonized the response to Ach indicating the presence of muscarinic cholinoceptors on the heart of early embryos. However, atropine injections had no impact on heart rate until immediately before hatching, when it increased heart rate by 15%. This cholinergic tonus increased to 34% in hatchlings and dropped to 24% in adult iguanas. Although epinephrine was without effect, injection of propranolol slowed the heart throughout development, indicating the presence of β-adrenergic receptors on the heart of early embryos, possibly stimulated by high levels of circulating catecholamines. The calculated excitatory tonus varied between 33% and 68% until immediately before hatching when it fell to 25% and 29%, a level retained in hatchlings and adults. Hypoxia caused a bradycardia in early embryos that was unaffected by injection of atropine indicating that hypoxia has a direct effect upon the heart. In later embryos and hatchlings hypoxia caused a tachycardia that was unaffected by injection of atropine. Subsequent injection of propranolol reduced heart rate both uncovering a hypoxic bradycardia in late embryos and abolishing tachycardia in hatchlings. Hypercapnia was without effect on heart rate in late stage embryos and in hatchlings. Copyright © 2015 Elsevier Inc. All rights reserved.

Influences of sire conception rate on pregnancy establishment in dairy cattle.

PubMed

Ortega, M Sofia; Moraes, João G N; Patterson, David J; Smith, Michael F; Behura, Susanta K; Poock, Scott; Spencer, Thomas E

2018-06-19

Establishment of pregnancy in cattle is complex and encompasses ovulation, fertilization, blastocyst formation and growth into an elongated conceptus, pregnancy recognition signaling, and development of the embryo and placenta. The objective here was to investigate sire influences on pregnancy establishment in cattle. First, 10 Holstein bulls were classified as high or low fertility based on their sire conception rate (SCR) value. In a field trial, pregnancy at first timed insemination was not different between high and low SCR bulls. Next, 5 of the 10 sires were phenotyped using In Vitro and In Vivo embryo production. There was no effect of SCR classification on in vitro embryo cleavage rate, but low SCR sires produced fewer day 8 blastocysts. In superovulated heifers, high SCR bulls produced a lower percentage of unfertilized oocytes and fewer degenerated embryos compared to low SCR bulls. Recipient heifers the received 3-5 In Vivo produced embryos from either high or low SCR sires on day 7 post-estrus. Day 16 conceptus recovery and length were not different between SCR groups, and the conceptus transcriptome was not appreciably different between high and low SCR sires. The reduced ability of embryos from low SCR bulls to establish pregnancy is multifactorial and encompasses sperm fertilizing ability, pre-implantation embryonic development, and development of the embryo and placenta after conceptus elongation and pregnancy recognition. These studies highlight the importance of understanding genetic contributions of the sire to pregnancy establishment that is crucial to increase reproductive efficiency in dairy cattle.

Effects of copper and arsenic stress on the development of Norway spruce somatic embryos and their visualization with the environmental scanning electron microscope.

PubMed

Đorđević, Biljana; Neděla, Vilém; Tihlaříková, Eva; Trojan, Václav; Havel, Ladislav

2018-05-18

Somatic embryogenesis is an important biotechnological technique which can be used in studies associated with environmental stress. Four embryogenic cell lines of Norway spruce were grown on media enriched with copper and arsenic in concentration ranges 50-500 μM and 10-50 μM, respectively. The effects were observed during subsequent stages of somatic embryogenesis, the characteristics evaluated being proliferation potential, average number of somatic embryos obtained per g/fresh weight, morphology of developed somatic embryos, metal uptake, and microanalysis of macro- and micronutrients uptake. Copper and arsenic at higher concentrations significantly reduced the growth of early somatic embryos. In almost all treatments, the cell line V-1-3 showed the best performance compared with the other lines tested. Environmental scanning electron microscopy was used to visualize and identify morphological abnormalities in the development of somatic embryos. Abnormalities observed were classified into several categories: meristemless somatic embryos, somatic embryos with disrupted meristem, reduced number of cotyledons, single cotyledon and fused cotyledons. With the application of a low temperature method for the environmental scanning electron microscope, samples were stabilized and whole meristems could be investigated in their native state. As far as we are aware, this is the first report of the effect of copper and arsenic during the process of somatic embryogenesis and the first to evaluate the content of macro and micronutrients uptake in Norway spruce. Copyright © 2018 Elsevier B.V. All rights reserved.

The Use of "Kryptolebias marmoratus" Eggs as an Educational Tool for Embryology Education

ERIC Educational Resources Information Center

Genade, Tyrone

2016-01-01

Plastic embryological models lack the excitement of seeing real, live embryos. Chick embryos are often used to demonstrate embryological development and blood circulation to students but this necessitates the death of the organism. "Kryptolebias marmoratus" embryos are large and can be viewed by means of a light microscope without need…

Embryo-specific expression of a visual reporter gene as a selection system for citrus transformation

PubMed Central

Zambon, Flavia T.; Erpen, Lígia; Soriano, Leonardo; Grosser, Jude

2018-01-01

The embryo-specific Dc3 gene promoter driving the VvMybA1 anthocyanin regulatory gene was used to develop a visual selection system for the genetic transformation of citrus. Agrobacterium-mediated transformation of cell suspension cultures resulted in the production of purple transgenic somatic embryos that could be easily separated from the green non-transgenic embryos. The somatic embryos produced phenotypically normal plants devoid of any visual purple coloration. These results were also confirmed using protoplast transformation. There was minimal gene expression in unstressed one-year-old transgenic lines. Cold and drought stress did not have any effect on gene expression, while exogenous ABA and NaCl application resulted in a minor change in gene expression in several transgenic lines. When gas exchange was measured in intact leaves, the transgenic lines were similar to controls under the same environment. Our results provide conclusive evidence for the utilization of a plant-derived, embryo-specific visual reporter system for the genetic transformation of citrus. Such a system could aid in the development of an all-plant, consumer-friendly GM citrus tree. PMID:29293649

Regulation of Embryo Dormancy by Manipulation of Abscisic Acid in Kernels and Associated Cob Tissue of Zea mays L. Cultured in Vitro1

PubMed Central

Hole, David J.; Smith, J. D.; Cobb, B. Greg

1989-01-01

Sectors of Zea mays cobs, with and without kernels were cultured in vitro in the presence and absence of fluridone. Cultured kernels, cob tissue, and embryos developed similarly to those grown in the field. Abscisic acid (ABA) levels in the embryos were evaluated by enzyme-linked immunosorbant assay. ABA levels in intact embryos cultured in the presence of fluridone were extremely low and indicate an inhibition of ABA synthesis. ABA levels in isolated cob tissue indicate that ABA can be produced by cob tissue. Sections containing kernels cultured in the presence of fluridone were transferred to medium containing fluridone and ABA. Dormancy was induced in more than 50% of the kernels transferred from 13 to 15 days after pollination, but all of the kernels transferred at 16 days after pollination or later were viviparous. ABA recovered from kernels that were placed in medium containing fluridone and ABA suggest that ABA can be transported through the cob tissue into developing embryos and that ABA is required for induction of dormancy in intact embryos. PMID:16666978

Mechanical control of notochord morphogenesis by extra-embryonic tissues in mouse embryos.

PubMed

Imuta, Yu; Koyama, Hiroshi; Shi, Dongbo; Eiraku, Mototsugu; Fujimori, Toshihiko; Sasaki, Hiroshi

2014-05-01

Mammalian embryos develop in coordination with extraembryonic tissues, which support embryonic development by implanting embryos into the uterus, supplying nutrition, providing a confined niche, and also providing patterning signals to embryos. Here, we show that in mouse embryos, the expansion of the amniotic cavity (AC), which is formed between embryonic and extraembryonic tissues, provides the mechanical forces required for a type of morphogenetic movement of the notochord known as convergent extension (CE) in which the cells converge to the midline and the tissue elongates along the antero-posterior (AP) axis. The notochord is stretched along the AP axis, and the expansion of the AC is required for CE. Both mathematical modeling and physical simulation showed that a rectangular morphology of the early notochord caused the application of anisotropic force along the AP axis to the notochord through the isotropic expansion of the AC. AC expansion acts upstream of planar cell polarity (PCP) signaling, which regulates CE movement. Our results highlight the importance of extraembryonic tissues as a source of the forces that control the morphogenesis of embryos. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Embryos of non-native anoles are robust to urban thermal environments.

PubMed

Tiatragul, Sarin; Kurniawan, Audeline; Kolbe, Jason J; Warner, Daniel A

2017-04-01

The transformation of natural habitats into urban landscapes dramatically alters thermal environments, which in turn, can impact local biota. Ectothermic organisms that are oviparous are particularly sensitive to these altered environments because their embryos cannot behaviorally thermoregulate and the surrounding environment determines the temperature experienced during development. We studied the effects of urban and forested thermal environments on embryo development and hatchling phenotypes in two non-native lizards (Anolis sagrei and A. cristatellus) in metropolitan Miami, Florida. To determine if embryos from urban and forested sites are adapted to their respective thermal environments, we incubated eggs from each site using temperatures that simulate likely nest conditions in both urban and forested environments. For both species, urban thermal environments accelerated embryonic development, but had no impact on egg survival or any of the phenotypic traits that were measured (e.g., body size, running performance, and locomotor behavior). Our results provide no evidence that embryos from urban and forested sites are adapted to their respective thermal environments. Instead, the lack of any major effects suggest that embryos of both species are physiologically robust with respect to novel environments, which could have facilitated their success in establishing in non-native ranges and in human-modified landscapes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Raman-based noninvasive metabolic profile evaluation of in vitro bovine embryos

NASA Astrophysics Data System (ADS)

dos Santos, Érika Cristina; Martinho, Herculano; Annes, Kelly; da Silva, Thais; Soares, Carlos Alexandre; Leite, Roberta Ferreira; Milazzotto, Marcella Pecora

2016-07-01

The timing of the first embryonic cell divisions may predict the ability of an embryo to establish pregnancy. Similarly, metabolic profiles may be markers of embryonic viability. However, in bovine, data about the metabolomics profile of these embryos are still not available. In the present work, we describe Raman-based metabolomic profiles of culture media of bovine embryos with different developmental kinetics (fast x slow) throughout the in vitro culture. The principal component analysis enabled us to classify embryos with different developmental kinetics since they presented specific spectroscopic profiles for each evaluated time point. We noticed that bands at 1076 cm-1 (lipids), 1300 cm-1 (Amide III), and 2719 cm-1 (DNA nitrogen bases) gave the most relevant spectral features, enabling the separation between fast and slow groups. Bands at 1001 cm-1 (phenylalanine) and 2892 cm-1 (methylene group of the polymethylene chain) presented specific patterns related to embryonic stage and can be considered as biomarkers of embryonic development by Raman spectroscopy. The culture media analysis by Raman spectroscopy proved to be a simple and sensitive technique that can be applied with high efficiency to characterize the profiles of in vitro produced bovine embryos with different development kinetics and different stages of development.

Development of a security system for assisted reproductive technology (ART).

PubMed

Hur, Yong Soo; Ryu, Eun Kyung; Park, Sung Jin; Yoon, Jeong; Yoon, San Hyun; Yang, Gi Deok; Hur, Chang Young; Lee, Won Don; Lim, Jin Ho

2015-01-01

In the field of assisted reproductive technology (ART), medical accidents can result in serious legal and social consequences. This study was conducted to develop a security system (called IVF-guardian; IG) that could prevent mismatching or mix-ups in ART. A software program was developed in collaboration with outside computer programmers. A quick response (QR) code was used to identify the patients, gametes and embryos in a format that was printed on a label. There was a possibility that embryo development could be affected by volatile organic components (VOC) in the printing material and adhesive material in the label paper. Further, LED light was used as the light source to recognize the QR code. Using mouse embryos, the effects of the label paper and LED light were examined. The stability of IG was assessed when applied in clinical practice after developing the system. A total of 104 cycles formed the study group, and 82 cycles (from patients who did not want to use IG because of safety concerns and lack of confidence in the security system) to which IG was not applied comprised the control group. Many of the label paper samples were toxic to mouse embryo development. We selected a particular label paper (P touch label) that did not affect mouse embryo development. The LED lights were non-toxic to the development of the mouse embryos under any experimental conditions. There were no differences in the clinical pregnancy rates between the IG-applied group and the control group (40/104 = 38.5 % and 30/82 = 36.6 %, respectively). The application of IG in clinical practice did not affect human embryo development or clinical outcomes. The use of IG reduces the misspelling of patient names. Using IG, there was a disadvantage in that each treatment step became more complicated, but the medical staff improved and became sufficiently confident in ART to offset this disadvantage. Patients who received treatment using the IG system also went through a somewhat tedious process, but there were no complaints. These patients gained further confidence in the practitioners over the course of treatment.

Avian embryonic development in hyperdynamic environments

NASA Technical Reports Server (NTRS)

Abbott, U. K.; Smith, A. H.

1983-01-01

Embryos which developed for 24 hours in the oviduct of hens maintained at 2 G and which were subsequently incubated at Earth gravity had a 14% reduction in hatchability. Increased mortality during the first 4 days, and an increase in embryonic abnormalities were of the types usually found during the first mortality peak (2-3 days). Embryos in eggs that were produced at Earth gravity and continued their development on the centrifuge at fields of 2 G or less did not appear to be greatly affected by the treatment. At 4 G, 91% of the embryos died, mostly on the first and second days of incubation. Abnormalities prominent in the centrifuged eggs include: (a) a failure of the primitive streak to develop; (b) interference with the development of the axial skeleton; (c) multiple hemorrhages, mostly petechial which is consistent with capillary fragility; and (d) retardation of embryo growth, possibly caused by an interference with gaseous diffusion, the result of an acceleration-induced increase in gas density in the centrifuging incubator.

Non-destructive monitoring of mouse embryo development and its qualitative evaluation at the molecular level using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Ishigaki, Mika; Hashimoto, Kosuke; Sato, Hidetoshi; Ozaki, Yukihiro

2017-03-01

Current research focuses on embryonic development and quality not only by considering fundamental biology, but also by aiming to improve assisted reproduction technologies, such as in vitro fertilization. In this study, we explored the development of mouse embryo and its quality based on molecular information, obtained nondestructively using Raman spectroscopy. The detailed analysis of Raman spectra measured in situ during embryonic development revealed a temporary increase in protein content after fertilization. Proteins with a β-sheet structure—present in the early stages of embryonic development—are derived from maternal oocytes, while α-helical proteins are additionally generated by switching on a gene after fertilization. The transition from maternal to embryonic control during development can be non-destructively profiled, thus facilitating the in situ assessment of structural changes and component variation in proteins generated by metabolic activity. Furthermore, it was indicated that embryos with low-grade morphology had high concentrations of lipids and hydroxyapatite. This technique could be used for embryo quality testing in the future.

Embryo loss in cattle between Days 7 and 16 of pregnancy.

PubMed

Berg, D K; van Leeuwen, J; Beaumont, S; Berg, M; Pfeffer, P L

2010-01-15

Embryo loss between embryonic Days 7 and 16 (Day 0=day of IVF) in nonlactating cattle, Bos taurus, was analyzed using transfer of 2449 (in groups of 3 to 30) in vitro-produced (IVP) blastocysts. In 152 transfers, pregnancy losses attributable solely to recipient failings amounted to between 6% (beef heifers) and 16% (parous dairy cows), of which 3% were caused by uterine infections. Neither season, year, nor the age of the embryos on retrieval affected pregnancy rates. The latter observation indicated that the reason that a recipient failed to retain embryos was already present at the time of transfer. Notably, the proportion of embryos recovered decreased (P=0.03) as more embryos were transferred, particularly at later stages (Day 14, P<0.01). The average length of embryos decreased by approximately 5% for every additional embryo transferred (P<0.0001). These effects may be linked to embryonic migration. Embryo mortality inherent to the embryo during the second week of pregnancy was 24%. Additionally, 9% of Day 14 embryos were of inferior quality, as they did not contain an epiblast. Combining embryo and recipient causes but excluding infection effects, embryonic loss of IVP embryos during the second week of pregnancy amounted to 26% (heifers) or 34% (parous dairy cows). The length of embryos doubled every day between Days 9 and 16, with a 4.4-fold range in sizes representing two thirds of the variation in length. Embryos retrieved from heifers were twice the size of those incubated in parous cows (P<0.0001), indicating faster embryonic development/trophoblast proliferation in heifers. Whereas season did not affect embryo recoveries, length was lower (50%) in winter (winter-autumn, P<0.05; winter-spring, P<0.001). Lastly, transuterine migration in cattle, when transferring multiple embryos, commenced at Day 14 (4%) and had occurred in all recipients by Day 16 (38% of embryos found contralaterally).

Maternal source of variability in the embryo development of an annual killifish.

PubMed

Polačik, M; Smith, C; Reichard, M

2017-04-01

Organisms inhabiting unpredictable environments often evolve diversified reproductive bet-hedging strategies, expressed as production of multiple offspring phenotypes, thereby avoiding complete reproductive failure. To cope with unpredictable rainfall, African annual killifish from temporary savannah pools lay drought-resistant eggs that vary widely in the duration of embryo development. We examined the sources of variability in the duration of individual embryo development, egg production and fertilization rate in Nothobranchius furzeri. Using a quantitative genetics approach (North Carolina type II design), we found support for maternal effects rather than polyandrous mating as the primary source of the variability in the duration of embryo development. The number of previously laid eggs appeared to serve as an internal physiological cue initiating a shift from rapid-to-slow embryo developmental mode. In annual killifish, extensive phenotypic variability in progeny traits is adaptive, as the conditions experienced by parents have limited relevance to the offspring generation. In contrast to genetic control, with high phenotypic expression and heritability, maternal control of traits under natural selection prevents standing genetic diversity from potentially detrimental effects of selection in fluctuating environments. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Apoptosis regulates notochord development in Xenopus.

PubMed

Malikova, Marina A; Van Stry, Melanie; Symes, Karen

2007-11-15

The notochord is the defining characteristic of the chordate embryo and plays critical roles as a signaling center and as the primitive skeleton. In this study we show that early notochord development in Xenopus embryos is regulated by apoptosis. We find apoptotic cells in the notochord beginning at the neural groove stage and increasing in number as the embryo develops. These dying cells are distributed in an anterior to posterior pattern that is correlated with notochord extension through vacuolization. In axial mesoderm explants, inhibition of this apoptosis causes the length of the notochord to approximately double compared to controls. In embryos, however, inhibition of apoptosis decreases the length of the notochord and it is severely kinked. This kinking also spreads from the anterior with developmental stage such that, by the tadpole stage, the notochord lacks any recognizable structure, although notochord markers are expressed in a normal temporal pattern. Extension of the somites and neural plate mirrors that of the notochord in these embryos, and the somites are severely disorganized. These data indicate that apoptosis is required for normal notochord development during the formation of the anterior-posterior axis, and its role in this process is discussed.