G protein-coupled estrogen receptor regulates embryonic heart rate in zebrafish

PubMed Central

Romano, Shannon N.; Edwards, Hailey E.; Ryan, Kevin J.

2017-01-01

Estrogens act by binding to estrogen receptors alpha and beta (ERα, ERβ), ligand-dependent transcription factors that play crucial roles in sex differentiation, tumor growth and cardiovascular physiology. Estrogens also activate the G protein-coupled estrogen receptor (GPER), however the function of GPER in vivo is less well understood. Here we find that GPER is required for normal heart rate in zebrafish embryos. Acute exposure to estrogens increased heart rate in wildtype and in ERα and ERβ mutant embryos but not in GPER mutants. GPER mutant embryos exhibited reduced basal heart rate, while heart rate was normal in ERα and ERβ mutants. We detected gper transcript in discrete regions of the brain and pituitary but not in the heart, suggesting that GPER acts centrally to regulate heart rate. In the pituitary, we observed gper expression in cells that regulate levels of thyroid hormone triiodothyronine (T3), a hormone known to increase heart rate. Compared to wild type, GPER mutants had reduced levels of T3 and estrogens, suggesting pituitary abnormalities. Exposure to exogenous T3, but not estradiol, rescued the reduced heart rate phenotype in gper mutant embryos, demonstrating that T3 acts downstream of GPER to regulate heart rate. Using genetic and mass spectrometry approaches, we find that GPER regulates maternal estrogen levels, which are required for normal embryonic heart rate. Our results demonstrate that estradiol plays a previously unappreciated role in the acute modulation of heart rate during zebrafish embryonic development and suggest that GPER regulates embryonic heart rate by altering maternal estrogen levels and embryonic T3 levels. PMID:29065151

G protein-coupled estrogen receptor regulates embryonic heart rate in zebrafish.

PubMed

Romano, Shannon N; Edwards, Hailey E; Souder, Jaclyn Paige; Ryan, Kevin J; Cui, Xiangqin; Gorelick, Daniel A

2017-10-01

Estrogens act by binding to estrogen receptors alpha and beta (ERα, ERβ), ligand-dependent transcription factors that play crucial roles in sex differentiation, tumor growth and cardiovascular physiology. Estrogens also activate the G protein-coupled estrogen receptor (GPER), however the function of GPER in vivo is less well understood. Here we find that GPER is required for normal heart rate in zebrafish embryos. Acute exposure to estrogens increased heart rate in wildtype and in ERα and ERβ mutant embryos but not in GPER mutants. GPER mutant embryos exhibited reduced basal heart rate, while heart rate was normal in ERα and ERβ mutants. We detected gper transcript in discrete regions of the brain and pituitary but not in the heart, suggesting that GPER acts centrally to regulate heart rate. In the pituitary, we observed gper expression in cells that regulate levels of thyroid hormone triiodothyronine (T3), a hormone known to increase heart rate. Compared to wild type, GPER mutants had reduced levels of T3 and estrogens, suggesting pituitary abnormalities. Exposure to exogenous T3, but not estradiol, rescued the reduced heart rate phenotype in gper mutant embryos, demonstrating that T3 acts downstream of GPER to regulate heart rate. Using genetic and mass spectrometry approaches, we find that GPER regulates maternal estrogen levels, which are required for normal embryonic heart rate. Our results demonstrate that estradiol plays a previously unappreciated role in the acute modulation of heart rate during zebrafish embryonic development and suggest that GPER regulates embryonic heart rate by altering maternal estrogen levels and embryonic T3 levels.

Delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx.

PubMed

Meenakumari, Karukayil J; Krishna, Amitabh

2005-01-01

The unusual feature of the breeding cycle of Cynopterus sphinx at Varanasi is the significant variation in gestation length of the two successive pregnancies of the year. The aim of this study was to investigate whether the prolongation of the first pregnancy in C. sphinx is due to delayed embryonic development. The first (winter) pregnancy commences in late October and lasts until late March and has a gestation period of about 150 days. The second (summer) pregnancy commences in April and lasts until the end of July or early August with a gestation period of about 125 days. Changes in the size and weight of uterine cornua during the two successive pregnancies suggest retarded embryonic growth during November and December. Histological analysis during the period of retarded embryonic development in November and December showed a slow gastrulation process. The process of amniogenesis was particularly slow. When the embryos attained the early primitive streak stage, their developmental rate suddenly increased considerably. During the summer pregnancy, on the other hand, the process of gastrulation was much faster and proceeded quickly. A comparison of the pattern of embryonic development for 4 consecutive years consistently showed retarded or delayed embryonic development during November and December. The time of parturition and post-partum oestrus showed only a limited variation from 1 year to another. This suggests that delayed embryonic development in C. sphinx may function to synchronize parturition among females. The period of delayed embryonic development in this species clearly coincides with the period of fat deposition. The significance of this correlation warrants further investigation.

Stability of citrate-capped silver nanoparticles in exposure media and their effects on the development of embryonic zebrafish (Danio rerio)

PubMed Central

Park, Kwangsik; Tuttle, George; Sinche, Federico; Harper, Stace L.

2014-01-01

The stability of citrate-capped silver nanoparticles (AgNPs) and the embryonic developmental toxicity were evaluated in the fish test water. Serious aggregation of AgNPs was observed in undiluted fish water (DM-100) in which high concentration of ionic salts exist. However, AgNPs were found to be stable for 7 days in DM-10, prepared by diluting the original fish water (DM-100) with deionized water to 10%. The normal physiology of zebrafish embryos were evaluated in DM-10 to see if DM-10 can be used as a control vehicle for the embryonic fish toxicity test. As results, DM-10 without AgNPs did not induce any significant adverse effects on embryonic development of zebrafish determined by mortality, hatching, malformations and heart rate. When embryonic toxicity of AgNPs was tested in both DM-10 and in DM-100, AgNPs showed higher toxicity in DM-10 than in DM-100. This means that the big-sized aggregates of AgNPs were low toxic compared to the nano-sized AgNPs. AgNPs induced delayed hatching, decreased heart rate, pericardial edema, and embryo death. Accumulation of AgNPs in the embryo bodies was also observed. Based on this study, citrate-capped AgNPs are not aggregated in DM-10 and it can be used as a control vehicle in the toxicity test of fish embryonic development. PMID:23325492

Developmental cardiovascular physiology of the olive ridley sea turtle (Lepidochelys olivacea).

PubMed

Crossley, Dane Alan; Crossley, Janna Lee; Smith, Camilla; Harfush, Martha; Sánchez-Sánchez, Hermilo; Garduño-Paz, Mónica Vanessa; Méndez-Sánchez, José Fernando

2017-09-01

Our understanding of reptilian cardiovascular development and regulation has increased substantially for two species the American alligator (Alligator mississippiensis) and the common snapping turtle (Chelydra serpentina) during the past two decades. However, what we know about cardiovascular maturation in many other species remains poorly understood or unknown. Embryonic sea turtles have been studied to understand the maturation of metabolic function, but these studies have not addressed the cardiovascular system. Although prior studies have been pivotal in characterizing development, and factors that influence it, the development of cardiovascular function, which supplies metabolic function, is unknown in sea turtles. During our investigation we focused on quantifying how cardiovascular morphological and functional parameters change, to provide basic knowledge of development in the olive ridley sea turtle (Lepidochelys olivacea). Embryonic mass, as well as mass of the heart, lungs, liver, kidney, and brain increased during turtle embryo development. Although heart rate was constant during this developmental period, arterial pressure approximately doubled. Further, while embryonic olive ridley sea turtles lacked cholinergic tone on heart rate, there was a pronounced beta adrenergic tone on heart rate that decreased in strength at 90% of incubation. This beta adrenergic tone may be partially originating from the sympathetic nervous system at 90% of incubation, with the majority originating from circulating catecholamines. Data indicates that olive ridley sea turtles share traits of embryonic functional cardiovascular maturation with the American alligator (Alligator mississippiensis) but not the common snapping turtle (Chelydra serpentina). Copyright © 2017 Elsevier Inc. All rights reserved.

Rates of oxygen uptake increase independently of changes in heart rate in late stages of development and at hatching in the green iguana, Iguana iguana.

PubMed

Sartori, Marina R; Abe, Augusto S; Crossley, Dane A; Taylor, Edwin W

2017-03-01

Oxygen consumption (VO 2 ), heart rate (f H ), heart mass (M h ) and body mass (M b ) were measured during embryonic incubation and in hatchlings of green iguana (Iguana iguana). Mean f H and VO 2 were unvarying in early stage embryos. VO 2 increased exponentially during the later stages of embryonic development, doubling by the end of incubation, while f H was constant, resulting in a 2.7-fold increase in oxygen pulse. Compared to late stage embryos, the mean inactive level of VO 2 in hatchlings was 1.7 fold higher, while f H was reduced by half resulting in a further 3.6 fold increase in oxygen pulse. There was an overall negative correlation between mean f H and VO 2 when data from hatchlings was included. Thus, predicting metabolic rate as VO 2 from measurements of f H is not possible in embryonic reptiles. Convective transport of oxygen to supply metabolism during embryonic incubation was more reliably indicated as an index of cardiac output (CO i ) derived from the product of f H and M h . However, a thorough analysis of factors determining rates of oxygen supply during development and eclosion in reptiles will require cannulation of blood vessels that proved impossible in the present study, to determine oxygen carrying capacity by the blood and arteriovenous oxygen content difference (A-V diff), plus patterns of blood flow. Copyright © 2016 Elsevier Inc. All rights reserved.

Role of leptin in delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx.

PubMed

Banerjee, A; Meenakumari, K J; Krishna, A

2010-08-01

An adiposity-associated rise in leptin occurs at the time of delayed embryonic development in Cynopterus sphinx. The aim of present study was to examine the mechanism by which leptin may inhibit progesterone, and therefore could be responsible for delayed development. The study showed a significant increase in circulating leptin level during the period of increased fat accumulation, which coincided with significant decrease in serum progesterone level and delayed embryonic development in C. sphinx. The study showed increased Ob-R expression in the corpus luteum and in the utero-embryonic unit during the period of delayed embryonic development. The in vitro study showed suppressive effect of leptin on progesterone synthesis. The effect of high dose of leptin on ovarian steroidogenesis was found to be mediated through decreased expression of StAR and LH-R proteins in the ovary. The treatment with leptin caused increased expression of STAT 3 and iNOS proteins in the ovary, which correlated with decreased expression of StAR protein in the ovary. The inhibitory effects of leptin on progesterone synthesis in the ovary are thus mediated through STAT 3 and iNOS-NO signaling pathways. This study further demonstrated low expression of PCNA coinciding with the increased concentration of the leptin receptor in the utero-embryonic unit and high circulating leptin level during November. In conclusion, adiposity associated increased leptin level during November-December might play role in suppressing progesterone synthesis in the corpus luteum as well as suppressing the rate of cell-proliferation in the utero-embryonic unit thereby causing delayed embryonic development in C. sphinx. Copyright 2010 Elsevier Inc. All rights reserved.

[Effects of temperature on the embryonic development and larval growth of Sepia lycidas].

PubMed

Jiang, Xia-Min; Peng, Rui-Bing; Luo, Jiang; Tang, Feng

2013-05-01

A single-factor experiment was conducted to study the effects of different temperature (15, 18, 21, 24, 27, 30, and 33 degrees C) on the embryonic development and larval growth of Sepia lycidas, aimed to search for the optimum temperature for the development and growth of S. lycidas. The results showed that temperature had significant effects on the embryonic development and larval growth of S. lycidas (P < 0.05). The suitable temperature for hatching ranged from 21 degrees C to 30 degrees C, and the optimum temperature was 24 degrees C. At the optimum temperature, the hatching rate was (93.3 +/- 2.9)%, incubation period was (24.33 +/- 0.58) d, hatching period was (6.00 +/- 1.00) d, completely absorked rate of yolk sac was (96.4 +/- 3.1)%, and newly hatched larvae mass was (0.258 +/- 0.007) g. The effective accumulated temperature model was N = 284.42/(T-12.57). The suitable temperature for the larval survival and growth ranged from 21 degrees C to 30 degrees C, and the optimum temperature was from 24 degrees C to 27 degrees C. At the optimum temperature, the survival rate ranged from 70.0% to 73.3%, and the specific growth rate was from 2.4% to 3.8%.

Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate.

PubMed

Martin, Thomas E; Ton, Riccardo; Niklison, Alina

2013-06-01

Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species. © 2013 John Wiley & Sons Ltd/CNRS.

Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate

USGS Publications Warehouse

Martin, Thomas E.; Ton, Riccardo; Nikilson, Alina

2013-01-01

Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species.

Parthenogenesis in unfertilized eggs of Coturnix chinensis, the Chinese painted quail, and the effect of egg clutch position on embryonic development.

PubMed

Parker, H M; McDaniel, C D

2009-04-01

Parthenogenesis, embryonic development of an unfertilized egg, was studied for many years in turkeys. In fact, as many as 49% of unfertilized Beltsville Small White turkey eggs develop embryos. However, no research exists on parthenogenesis in quail. The Chinese painted quail is a close relative of the more common Japanese quail and, unlike turkeys or chickens, the small Chinese painted quail reaches sexual maturity rapidly, making it a great candidate for further research on parthenogenesis. Obviously, a better understanding of avian parthenogenesis should increase our knowledge of avian fertilization and early embryonic development. Therefore, we determined if unfertilized Chinese painted quail hens produce embryos. Second, we explored the possibility that position of the egg within the clutch influences parthenogenesis. When initial secondary sexual plumage was apparent at 4 wk of age, male chicks were separated from females to prevent fertilization. Hens were placed in individual cages near sexual maturity, at approximately 6 wk of age. Individual eggs were collected daily and labeled with hen number and date. Eggs were stored for 0 to 3 d at 20 degrees C before incubation at 37.5 degrees C. After 10 d of incubation, approximately 4,000 eggs from 300 laying hens were examined for embryonic development under a magnifying lamp. On average, 4.8% of the unfertilized eggs contained an abortive form of embryonic development consisting of undifferentiated cells and unorganized membranes. Approximately 27% of the laying hens produced at least 1 egg with parthenogenic development. However, about 10% (30) of these hens exhibited a predisposition for parthenogenesis by producing 2 or more unfertilized eggs with embryonic development. Twenty percent of the eggs from 2 hens produced embryonic development. Additionally, the first egg laid in a clutch was most likely to produce embryonic development, with a steady decline in the percentage of eggs with embryonic development as position in the clutch increased. In conclusion, the Chinese painted quail does exhibit parthenogenesis and clutch position influences the rate of naturally occurring parthenogenesis.

Establishment of stem cell lines from nuclear transferred and parthenogenetically activated mouse oocytes for therapeutic cloning.

PubMed

Ju, Jin Young; Park, Chun Young; Gupta, Mukesh Kumar; Uhm, Sang Jun; Paik, Eun Chan; Ryoo, Zae Young; Cho, Youl Hee; Chung, Kil Saeng; Lee, Hoon Taek

2008-05-01

To establish embryonic stem cell lines from nuclear transfer of somatic cell nuclei isolated from the same oocyte donor and from parthenogenetic activation. The study also evaluated the effect of the micromanipulation procedure on the outcome of somatic cell nuclear transfer in mice. Randomized, prospective study. Hospital-based assisted reproductive technology laboratory. F(1) (C57BL/6 x 129P3/J) mice. Metaphase II-stage oocytes were either parthenogenetically activated or nuclear transferred with cumulus cell nuclei or parthenogenetically activated after a sham-manipulation procedure. Embryogenesis and embryonic stem cell establishment. The development rate to morula/blastocyst of nuclear transferred oocytes (27.9% +/- 5.9%) was significantly lower than that of the sham-manipulated (84.1% +/- 5.6%) or parthenogenetic (98.6% +/- 1.4%) groups. A sharp decrease in cleavage potential was obvious in the two- to four-cell transition for the nuclear transferred embryos (79.0% +/- 4.6% and 43.3% +/- 5.0%), implying incomplete nuclear reprogramming in arrested oocytes. However, the cleavage, as well as the development rate, of parthenogenetic and sham-manipulated groups did not differ significantly. The embryonic stem cell line establishment rate was higher from parthenogenetically activated oocytes (15.7%) than nuclear transferred (4.3%) or sham-manipulated oocytes (12.5%). Cell colonies from all groups displayed typical morphology of mice embryonic stem cells and could be maintained successfully with undifferentiated morphology after continuous proliferation for more than 120 passages still maintaining normal karyotype. All these cells were positive for mice embryonic stem cell markers such as Oct-4 and SSEA-1 based on immunocytochemistry and reverse transcriptase-polymerase chain reaction. The clonal origin of the ntES cell line and the parthenogenetic embryonic stem cell lines were confirmed by polymerase chain reaction analysis of the polymorphic markers. Blastocyst injection experiments demonstrated that these lines contributed to resulting chimeras and are germ-line competent. We report the establishment of ntES cell lines from somatic cells isolated from same individual. Our data also suggest that embryo micromanipulation procedure during the nuclear transfer procedure influences the developmental ability and embryonic stem cell establishment rate of nuclear transferred embryos.

The effect of minimal concentration of ethylene glycol (EG) combined with polyvinylpyrrolidone (PVP) on mouse oocyte survival and subsequent embryonic development following vitrification.

PubMed

Wang, Yao; Okitsu, Osamu; Zhao, Xiao-Ming; Sun, Yun; Di, Wen; Chian, Ri-Cheng

2014-01-01

Vitrification techniques employ a relatively high concentration of cryoprotectant in vitrification solutions. Exposure of oocytes to high concentrations of cryoprotectant is known to damage the oocytes via both cytotoxic and osmotic effects. Therefore, the key to successful vitrification of oocytes is to strike a balance between the usage of minimal concentration of cryoprotectant without compromising their cryoprotective actions. The minimal concentration of ethylene glycol (EG) on mouse oocyte survival and subsequent embryonic development was evaluated following vitrification-warming and parthenogenetic activation. Polyvinylpyrrolidone (PVP) combined with EG on mouse oocyte survival and subsequent embryonic development as well as morphology of the spindle and chromosome alignment were also evaluated. Vitrification system was adapted with JY Straw and the cooling rate was approximately 442-500 °C/min. In contrast, the warming rate was approximately 2,210-2,652 °C/min. Survival rate of oocytes increased significantly when 15 % EG was combined with 2 % PVP in vitrification solution (VS). The effect of combination of EG and PVP was not significant when the concentration of EG was 20 % and higher. Although there were no significant differences in embryonic development, the percentage of abnormal spindle and chromosome alignment was significantly higher in the oocytes without 2 % PVP in VS. Our data provide a proof of principle for oocyte vitrification that may not require a high concentration of cryoprotectant. There are synergic effects of EG combined with PVP for oocyte vitrification, which may provide important information to the field in developing less cytotoxic VS.

Mapping and expression of candidate genes for development rate in rainbow trout (Oncorhynchus mykiss)

USDA-ARS?s Scientific Manuscript database

Development rate has important implications for many aspects of an individual's biology. In rainbow trout (Oncorhynchus mykiss), a major QTL for embryonic development rate has been detected on chromosome 5, but at present, few candidate genes have been mapped to this region. This paucity of known ge...

Establishment of mouse embryonic stem cells from isolated blastomeres and whole embryos using three derivation methods

PubMed Central

González, Sheyla; Ibáñez, Elena

2010-01-01

Purpose The aim of the present study is to compare three previously described mouse embryonic stem cell derivation methods to evaluate the influence of culture conditions, number of isolated blastomeres and embryonic stage in the derivation process. Methods Three embryonic stem cell derivation methods: standard, pre-adhesion and defined culture medium method, were compared in the derivation from isolated blastomeres and whole embryos at 4- and 8-cell stages. Results A total of 200 embryonic stem cell lines were obtained with an efficiency ranging from 1.9% to 72%. Conclusions Using either isolated blastomeres or whole embryos, the highest rates of mouse embryonic stem cell establishment were achieved with the defined culture medium method and efficiencies increased as development progressed. Using isolated blastomeres, efficiencies increased in parallel to the proportion of the embryo volume used to start the derivation process. PMID:20862536

Measurement of wall shear stress in chick embryonic heart using optical coherence tomography

NASA Astrophysics Data System (ADS)

Ma, Zhenhe; Dou, Shidan; Zhao, Yuqian; Wang, Yi; Suo, Yanyan; Wang, Fengwen

2015-03-01

The cardiac development is a complicated process affected by genetic and environmental factors. Wall shear stress (WSS) is one of the components which have been proved to influence the morphogenesis during early stages of cardiac development. To study the mechanism, WSS measurement is a step with significant importance. WSS is caused by blood flow imposed on the inner surface of the heart wall and it can be determined by calculating velocity gradients of blood flow in a direction perpendicular to the wall. However, the WSS of the early stage embryonic heart is difficult to measure since the embryonic heart is tiny and beating fast. Optical coherence tomography (OCT) is a non-invasive imaging modality with high spatial and temporal resolution, which is uniquely suitable for the study of early stage embryonic heart development. In this paper, we introduce a method to measure the WSS of early stage chick embryonic heart based on high speed spectral domain optical coherence tomography (SDOCT). 4D (x,y,z,t) scan was performed on the outflow tract (OFT) of HH18 (~3 days of incubation) chick embryonic heart. After phase synchronization, OFT boundary segmentation, and OFT center line calculation, Doppler angle of the blood flow in the OFT can be achieved (This method has been described in previous publications). Combining with the Doppler OCT results, we calculate absolute blood flow velocity distribution in the OFT. The boundary of the OFT was segmented at each cross-sectional structural image, then geometrical center of the OFT can be calculated. Thus, the gradients of blood flow in radial direction can be calculated. This velocity gradient near the wall is termed wall shear rate and the WSS value is proportional to the wall shear rate. Based on this method, the WSS at different heart beating phase are compare. The result demonstrates that OCT is capable of early stage chicken embryonic heart WSS study.

Application of Carnegie stages of development to unify human and baboon ultrasound findings early in pregnancy.

PubMed

Santolaya-Forgas, Joaquin; De Leon-Luis, Juan; Friel, Lara A; Wolf, Roman

2007-09-01

The objective of this study was to determine if very early ultrasonographic measurements obtained from human and baboon are comparable. For this purpose, the gestational, amniotic and yolk sacs, embryonic crown rump length (CRL) and heart rate were measured ultrasonographically between 35 and 47 days from the mean day of a three-day mating period in baboons (n=18) and between 42 to 58 days from fertilization as calculated from the CRL measurements in human pregnancies (n=82). Ultrasonographic measurements from both species were then plotted in the same graph using Carnegie stages of embryonic development as the independent variable to allow for visual comparisons. Mean gestational age at ultrasonographic studies was significantly different for humans and baboons (50.4 vs. 41 days, respectively; p>0.01). Significant correlations (p>0.01) were noted between ultrasonographic measurements and Carnegie stages of development in both humans and baboons. Only the gestational and the yolk sacs were significantly smaller in baboons than in humans (p>0.05). The findings that embryonic CRL, extra-embryonic space and heart rate are very similar between the 17th and 23rd Carnegie developmental stages make the baboon a promising surrogate of human pregnancy for investigations using celocentesis.

[Artificial propagation and embryonic development of Neolissochilus benasi].

PubMed

Pan, Xiao-Fu; Liu, Qian; Wang, Xiao-Ai; Yang, Jun-Xing; Chen, Xiao-Yong; Li, Zai-Yun; Li, Lie

2013-12-01

From 2009 to 2011, luteinizing hormone releasing hormone analogue (LHRH-A2) mixed with domperidon (DOM) was successfully applied during the artificial propagation of Neolissochilus benasi. Totally, 60 females and 100 males were injected with the hormone mixture, resulting in 47 (78.3%) females and 92 (92.0%) males being successfully spawned. A total of 1,986-5 854 eggs were spawned per female with an egg diameter varying between 2.2-2.8 mm, and an average nucleus deviation rate of 73.2%. Sperm density, vitality and life span were 16.32±2.89×10(9)/mL, 60.6±3.2% and 70.2±5.3 s, respectively. On the whole, the embryonic development of N. benasi was similar to that of zebra fish-albeit relatively slower-lasting approximately 120 hours. The development itself can be divided into six discrete stages: zygote, cleavage, blastula, gastrula, segmentation and hatching. Results showed that the average hatching rate was 32.4%, with 86.5% of larvae surviving 45 days after hatching. During embryonic development, deformities commonly occurred on the mouth, chest, ocular region, especially in the spinal column. To try to attempt improving future breeding efforts, we provided a survey of the embryonic developmental difficulties of N. benasi using LHRH-A2 followed by several potential solutions, including providing suitable breeding conditions and minimizing capture stresses.

Three-dimensional optical coherence tomography of the embryonic murine cardiovascular system

NASA Astrophysics Data System (ADS)

Luo, Wei; Marks, Daniel L.; Ralston, Tyler S.; Boppart, Stephen A.

2006-03-01

Optical coherence tomography (OCT) is an emerging high-resolution real-time biomedical imaging technology that has potential as a novel investigational tool in developmental biology and functional genomics. In this study, murine embryos and embryonic hearts are visualized with an OCT system capable of 2-µm axial and 15-µm lateral resolution and with real-time acquisition rates. We present, to our knowledge, the first sets of high-resolution 2- and 3-D OCT images that reveal the internal structures of the mammalian (murine) embryo (E10.5) and embryonic (E14.5 and E17.5) cardiovascular system. Strong correlations are observed between OCT images and corresponding hematoxylin- and eosin-stained histological sections. Real-time in vivo embryonic (E10.5) heart activity is captured by spectral-domain optical coherence tomography, processed, and displayed at a continuous rate of five frames per second. With the ability to obtain not only high-resolution anatomical data but also functional information during cardiovascular development, the OCT technology has the potential to visualize and quantify changes in murine development and in congenital and induced heart disease, as well as enable a wide range of basic in vitro and in vivo research studies in functional genomics.

Informing Stem Cell-Based Tendon Tissue Engineering Approaches with Embryonic Tendon Development.

PubMed

Okech, William; Kuo, Catherine K

Adult tendons fail to regenerate normal tissue after injury, and instead form dysfunctional scar tissue with abnormal mechanical properties. Surgical repair with grafts is the current standard to treat injuries, but faces significant limitations including pain and high rates of re-injury. To address this, we aim to regenerate new, normal tendons to replace dysfunctional tendons. A common approach to tendon tissue engineering is to design scaffolds and bioreactors based on adult tendon properties that can direct adult stem cell tenogenesis. Despite significant progress, advances have been limited due, in part, to a need for markers and potent induction cues. Our goal is to develop novel tendon tissue engineering approaches informed by embryonic tendon development. We are characterizing structure-property relationships of embryonic tendon to identify design parameters for three-dimensional scaffolds and bioreactor mechanical loading systems to direct adult stem cell tenogenesis. We will review studies in which we quantified changes in the mechanical and biochemical properties of tendon during embryonic development and elucidated specific mechanisms of functional property elaboration. We then examined the effects of these mechanical and biochemical factors on embryonic tendon cell behavior. Using custom-designed bioreactors, we also examined the effects of dynamic mechanical loading and growth factor treatment on embryonic tendon cells. Our findings have established cues to induce tenogenesis as well as metrics to evaluate differentiation. We finish by discussing how we have evaluated the tenogenic differentiation potential of adult stem cells by comparing their responses to that of embryonic tendon cells in these culture systems.

Postnatal growth rates covary weakly with embryonic development rates and do not explain adult mortality probability among songbirds on four continents.

PubMed

Martin, Thomas E; Oteyza, Juan C; Mitchell, Adam E; Potticary, Ahva L; Lloyd, Penn

2015-03-01

Growth and development rates may result from genetic programming of intrinsic processes that yield correlated rates between life stages. These intrinsic rates are thought to affect adult mortality probability and longevity. However, if proximate extrinsic factors (e.g., temperature, food) influence development rates differently between stages and yield low covariance between stages, then development rates may not explain adult mortality probability. We examined these issues based on study of 90 songbird species on four continents to capture the diverse life-history strategies observed across geographic space. The length of the embryonic period explained little variation (ca. 13%) in nestling periods and growth rates among species. This low covariance suggests that the relative importance of intrinsic and extrinsic influences on growth and development rates differs between stages. Consequently, nestling period durations and nestling growth rates were not related to annual adult mortality probability among diverse songbird species within or among sites. The absence of a clear effect of faster growth on adult mortality when examined in an evolutionary framework across species may indicate that species that evolve faster growth also evolve physiological mechanisms for ameliorating costs on adult mortality. Instead, adult mortality rates of species in the wild may be determined more strongly by extrinsic environmental causes.

Postnatal growth rates covary weakly with embryonic development rates and do not explain adult mortality probability among songbirds on four continents

USGS Publications Warehouse

Martin, Thomas E.; Oteyza, Juan C.; Mitchell, Adam E.; Potticary, Ahva L.; Lloyd, P.

2016-01-01

Growth and development rates may result from genetic programming of intrinsic processes that yield correlated rates between life stages. These intrinsic rates are thought to affect adult mortality probability and longevity. However, if proximate extrinsic factors (e.g., temperature, food) influence development rates differently between stages and yield low covariance between stages, then development rates may not explain adult mortality probability. We examined these issues based on study of 90 songbird species on four continents to capture the diverse life-history strategies observed across geographic space. The length of the embryonic period explained little variation (ca. 13%) in nestling periods and growth rates among species. This low covariance suggests that the relative importance of intrinsic and extrinsic influences on growth and development rates differs between stages. Consequently, nestling period durations and nestling growth rates were not related to annual adult mortality probability among diverse songbird species within or among sites. The absence of a clear effect of faster growth on adult mortality when examined in an evolutionary framework across species may indicate that species that evolve faster growth also evolve physiological mechanisms for ameliorating costs on adult mortality. Instead, adult mortality rates of species in the wild may be determined more strongly by extrinsic environmental causes.

Tretinoin-loaded lipid-core nanocapsules decrease reactive oxygen species levels and improve bovine embryonic development during in vitro oocyte maturation.

PubMed

Lucas, Caroline Gomes; Remião, Mariana Härter; Komninou, Eliza Rossi; Domingues, William Borges; Haas, Cristina; Leon, Priscila Marques Moura de; Campos, Vinicius Farias; Ourique, Aline; Guterres, Silvia S; Pohlmann, Adriana R; Basso, Andrea Cristina; Seixas, Fabiana Kömmling; Beck, Ruy Carlos Ruver; Collares, Tiago

2015-12-01

In vitro oocyte maturation (IVM) protocols can be improved by adding chemical supplements to the culture media. Tretinoin is considered an important retinoid in embryonic development and its association with lipid-core nanocapsules (TTN-LNC) represents an innovative way of improving its solubility, and chemical stability, and reducing its toxicity. The effects of supplementing IVM medium with TTN-LNC was evaluated by analyzing production of reactive oxygen species (ROS), S36-phosphorilated-p66Shc levels and caspase activity in early embryonic development, and expression of apoptosis and pluripotency genes in blastocysts. The lowest concentration tested (0.25μM) of TTN-LNC generated higher blastocyst rate, lower ROS production and S36-p66Shc amount. Additionally, expression of BAX and SHC1 were lower in both non-encapsulated tretinoin (TTN) and TTN-LNC-treated groups. Nanoencapsulation allowed the use of smaller concentrations of tretinoin to supplement IVM medium thus reducing toxic effects related with its use, decreasing ROS levels and apoptose frequency, and improving the blastocyst rates. Copyright © 2015 Elsevier Inc. All rights reserved.

Injurious Effects of Emodin on Maturation of Mouse Oocytes, Fertilization and Fetal Development via Apoptosis

PubMed Central

Chang, Mei-Hui; Chang, Shao-Chung; Chan, Wen-Hsiung

2012-01-01

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a major constituent of rhubarb, has a wide range of therapeutic applications. Previous studies have established that emodin induces apoptosis in the inner cell mass and trophectoderm of mouse blastocysts and leads to decreased embryonic development and viability, indicating a role as an injury risk factor for normal embryonic development. However, the mechanisms underlying its hazardous effects have yet to be characterized. In the current study, we further investigated the effects of emodin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, emodin induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with emodin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments using an in vivo mouse model disclosed that consumption of drinking water containing 20–40 μM emodin led to decreased oocyte maturation and in vitro fertilization, as well as early embryonic developmental injury. Notably, pretreatment with a caspase-3-specific inhibitor effectively prevented emodin-triggered injury effects, suggesting that impairment of embryo development occurs via a caspase-dependent apoptotic process. PMID:23203041

Injurious effects of emodin on maturation of mouse oocytes, fertilization and fetal development via apoptosis.

PubMed

Chang, Mei-Hui; Chang, Shao-Chung; Chan, Wen-Hsiung

2012-10-29

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a major constituent of rhubarb, has a wide range of therapeutic applications. Previous studies have established that emodin induces apoptosis in the inner cell mass and trophectoderm of mouse blastocysts and leads to decreased embryonic development and viability, indicating a role as an injury risk factor for normal embryonic development. However, the mechanisms underlying its hazardous effects have yet to be characterized. In the current study, we further investigated the effects of emodin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, emodin induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with emodin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments using an in vivo mouse model disclosed that consumption of drinking water containing 20-40 μM emodin led to decreased oocyte maturation and in vitro fertilization, as well as early embryonic developmental injury. Notably, pretreatment with a caspase-3-specific inhibitor effectively prevented emodin-triggered injury effects, suggesting that impairment of embryo development occurs via a caspase-dependent apoptotic process.

Impaired cardiac energy metabolism in embryos lacking adrenergic stimulation

PubMed Central

Baker, Candice N.; Gidus, Sarah A.; Price, George F.; Peoples, Jessica N. R.

2014-01-01

As development proceeds from the embryonic to fetal stages, cardiac energy demands increase substantially, and oxidative phosphorylation of ADP to ATP in mitochondria becomes vital. Relatively little, however, is known about the signaling mechanisms regulating the transition from anaerobic to aerobic metabolism that occurs during the embryonic period. The main objective of this study was to test the hypothesis that adrenergic hormones provide critical stimulation of energy metabolism during embryonic/fetal development. We examined ATP and ADP concentrations in mouse embryos lacking adrenergic hormones due to targeted disruption of the essential dopamine β-hydroxylase (Dbh) gene. Embryonic ATP concentrations decreased dramatically, whereas ADP concentrations rose such that the ATP/ADP ratio in the adrenergic-deficient group was nearly 50-fold less than that found in littermate controls by embryonic day 11.5. We also found that cardiac extracellular acidification and oxygen consumption rates were significantly decreased, and mitochondria were significantly larger and more branched in adrenergic-deficient hearts. Notably, however, the mitochondria were intact with well-formed cristae, and there was no significant difference observed in mitochondrial membrane potential. Maternal administration of the adrenergic receptor agonists isoproterenol or l-phenylephrine significantly ameliorated the decreases in ATP observed in Dbh−/− embryos, suggesting that α- and β-adrenergic receptors were effective modulators of ATP concentrations in mouse embryos in vivo. These data demonstrate that adrenergic hormones stimulate cardiac energy metabolism during a critical period of embryonic development. PMID:25516547

Embryonic hypoxia programmes postprandial cardiovascular function in adult common snapping turtles (Chelydra serpentina).

PubMed

Wearing, Oliver H; Conner, Justin; Nelson, Derek; Crossley, Janna; Crossley, Dane A

2017-07-15

Reduced oxygen availability (hypoxia) is a potent stressor during embryonic development, altering the trajectory of trait maturation and organismal phenotype. We previously documented that chronic embryonic hypoxia has a lasting impact on the metabolic response to feeding in juvenile snapping turtles ( Chelydra serpentina ). Turtles exposed to hypoxia as embryos [10% O 2 (H10)] exhibited an earlier and increased peak postprandial oxygen consumption rate, compared with control turtles [21% O 2 (N21)]. In the current study, we measured central blood flow patterns to determine whether the elevated postprandial metabolic response in H10 turtles is linked to lasting impacts on convective transport. Five years after hatching, turtles were instrumented to quantify systemic ([Formula: see text]) and pulmonary ([Formula: see text]) blood flows and heart rate ( f H ) before and after a ∼5% body mass meal. In adult N21 and H10 turtles, f H was increased significantly by feeding. Although total stroke volume ( V S,tot ) remained at fasted values, this tachycardia contributed to an elevation in total cardiac output ([Formula: see text]). However, there was a postprandial reduction in a net left-right (L-R) shunt in N21 snapping turtles only. Relative to N21 turtles, H10 animals exhibited higher [Formula: see text] due to increased blood flow through the right systemic outflow vessels of the heart. This effect of hypoxic embryonic development, reducing a net L-R cardiac shunt, may support the increased postprandial metabolic rate we previously reported in H10 turtles, and is further demonstration of adult reptile cardiovascular physiology being programmed by embryonic hypoxia. © 2017. Published by The Company of Biologists Ltd.

Reduced egg shell permeability affects embryonic development and hatchling traits in Lycodon rufozonatum and Pelodiscus sinensis.

PubMed

Tang, Wenqi; Zhao, Bo; Chen, Ye; DU, Weiguo

2018-01-01

The response of embryos to unpredictable hypoxia is critical for successful embryonic development, yet there remain significant gaps in our understanding of such responses in reptiles with different types of egg shell. We experimentally generated external regional hypoxia by sealing either the upper half or bottom half of the surface area of eggs in 2 species of reptiles (snake [Lycodon rufozonatum] with parchment egg shell and Chinese soft-shelled turtle [Pelodiscus sinensis] with rigid egg shell), then monitored the growth pattern of the opaque white patch in turtle eggs (a membrane that attaches the embryo to the egg shell and plays an important role in gas exchange), the embryonic heart rate, the developmental rate and the hatchling traits in turtle and snake eggs in response to external regional hypoxia. The snake embryos from the hypoxia treatments facultatively increased their heart rate during incubation, and turtle embryos from the upper-half hypoxia treatment enhanced their growth of the opaque white patch. Furthermore, the incubation period and hatching success of embryos were not affected by the hypoxia treatment in these 2 species. External regional hypoxia significantly affected embryonic yolk utilization and offspring size in the snake and turtle. Compared to sham controls, embryos from the upper-half hypoxia treatment used less energy from yolk and, therefore, developed into smaller hatchlings, but embryos from the bottom-half hypoxia treatment did not. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Cardiovascular development in embryos of the American alligator Alligator mississippiensis: effects of chronic and acute hypoxia.

PubMed

Crossley, Dane A; Altimiras, Jordi

2005-01-01

Chronic hypoxic incubation is a common tool used to address the plasticity of morphological and physiological characteristics during vertebrate development. In this study chronic hypoxic incubation of embryonic American alligators resulted in both morphological (mass) and physiological changes. During normoxic incubation embryonic mass, liver mass and heart mass increased throughout the period of study, while yolk mass fell. Chronic hypoxia (10%O2) resulted in a reduced embryonic mass at 80% and 90% of incubation. This reduction in embryonic mass was accompanied by a relative enlargement of the heart at 80% and 90% of incubation, while relative embryonic liver mass was similar to the normoxic group. Normoxic incubated alligators maintained a constant heart rate during the period of study, while mean arterial pressure rose continuously. Both levels of hypoxic incubation (15% and 10%O2) resulted in a lower mean arterial pressure at 90% of incubation, while heart rate was lower in the 10%O2 group only. Acute (5 min) exposure to 10%O2 in the normoxic group resulted in a biphasic response, with a normotensive bradycardia occurring during the period of exposure and a hypertensive tachycardic response occurring during recovery. The embryos incubated under hypoxia also showed a blunted response to acute hypoxic stress. In conclusion, the main responses elicited by chronic hypoxic incubation, namely, cardiac enlargement, blunted hypoxic response and systemic vasodilation, may provide chronically hypoxic embryos with a new physiological repertoire for responding to hypoxia.

Improving in vitro maturation and pregnancy outcome in cattle using a novel oocyte shipping and maturation system not requiring a CO₂ gas phase.

PubMed

Barceló-Fimbres, M; Campos-Chillón, L F; Mtango, N R; Altermatt, J; Bonilla, L; Koppang, R; Verstegen, J P

2015-07-01

The present work evaluated the benefit of a novel shipping and maturation medium (SMM) not requiring a CO2 gas for maturation and subsequent embryonic development of slaughterhouse and ovum pickup (OPU) bovine cumulus-oocyte complexes (COCs). Four experiments were conducted. In experiment 1, COCs were maturated for 18 hours in SMM and then incubated for 6 hours in, or 24 hours in a conventional system (control). Experiment 2 compared maturation for 24 hours in SMM versus 24 hours in the control. Experiment 3 compared three different incubation temperatures (37 °C, 38 °C, and 38.5 °C) for COCs maturation in SMM. In experiment 4, COCs obtained from 166 OPU sessions (representing two dairy and two beef breeds) in two locations (Wisconsin and California) were matured in SMM or control and evaluated relative to embryo production and pregnancy rates. Frozen semen was used for all experiments. The results for experiment 1 showed that the blastocyst rate and total embryo production rate (TE, Day-7 morulae plus all blastocysts) were higher for SMM than those in the control. However, no differences were observed for cleavage rate or blastocyst stage. In experiment 2, the blastocyst rate and TE were higher for SMM than those in the control; however, there was no difference for cleavage rate, total cell number, blastocyst stage. In experiment 3, the cleavage rate was similar, but the blastocyst rate and TE were greater for 38.5 °C than those for 38.0 °C and 37.5 °C. For experiment 4, Wisconsin OPU-derived COCs had a greater cleavage rate, blastocyst rate, TE, and blastocyst stage for SMM versus control. There were no breed effects. For the California trial, OPU-derived COCs matured in SMM had similar cleavage and pregnancy rates at Day 35 but greater blastocyst rates and transferred embryos per session than the control, which resulted in 2.2 more pregnancies per OPU session. Holstein COCs had superior embryonic development but similar pregnancy compared with Jersey. We conclude that COCs matured in SMM had greater oocyte competence than the control. Also, maturation at 38.5 °C in SMM was optimal for embryonic development. In summary, SMM resulted in greater embryonic development, similar pregnancy rates, but higher pregnancies per OPU session than the conventional maturation system. Copyright © 2015 Elsevier Inc. All rights reserved.

Adult mortality probability and nest predation rates explain parental effort in warming eggs with consequences for embryonic development time

USGS Publications Warehouse

Martin, Thomas E.; Oteyza, Juan C.; Boyce, Andy J.; Lloyd, Penn; Ton, Riccardo

2015-01-01

Parental behavior and effort vary extensively among species. Life-history theory suggests that age-specific mortality could cause this interspecific variation, but past tests have focused on fecundity as the measure of parental effort. Fecundity can cause costs of reproduction that confuse whether mortality is the cause or the consequence of parental effort. We focus on a trait, parental allocation of time and effort in warming embryos, that varies widely among species of diverse taxa and is not tied to fecundity. We conducted studies on songbirds of four continents and show that time spent warming eggs varies widely among species and latitudes and is not correlated with clutch size. Adult and offspring (nest) mortality explained most of the interspecific variation in time and effort that parents spend warming eggs, measured by average egg temperatures. Parental effort in warming eggs is important because embryonic temperature can influence embryonic development period and hence exposure time to predation risk. We show through correlative evidence and experimental swapping of embryos between species that parentally induced egg temperatures cause interspecific variation in embryonic development period. The strong association of age-specific mortality with parental effort in warming eggs and the subsequent effects on embryonic development time are unique results that can advance understanding of broad geographic patterns of life-history variation.

Live dynamic OCT imaging of cardiac structure and function in mouse embryos with 43 Hz direct volumetric data acquisition

NASA Astrophysics Data System (ADS)

Wang, Shang; Singh, Manmohan; Lopez, Andrew L.; Wu, Chen; Raghunathan, Raksha; Schill, Alexander; Li, Jiasong; Larin, Kirill V.; Larina, Irina V.

2016-03-01

Efficient phenotyping of cardiac dynamics in live mouse embryos has significant implications on understanding of early mammalian heart development and congenital cardiac defects. Recent studies established optical coherence tomography (OCT) as a powerful tool for live embryonic heart imaging in various animal models. However, current four-dimensional (4D) OCT imaging of the beating embryonic heart largely relies on gated data acquisition or postacquisition synchronization, which brings errors when cardiac cycles lack perfect periodicity and is time consuming and computationally expensive. Here, we report direct 4D OCT imaging of the structure and function of cardiac dynamics in live mouse embryos achieved by employing a Fourier domain mode-locking swept laser source that enables ~1.5 MHz A-line rate. Through utilizing both forward and backward scans of a resonant mirror, we obtained a ~6.4 kHz frame rate, which allows for a direct volumetric data acquisition speed of ~43 Hz, around 20 times of the early-stage mouse embryonic heart rate. Our experiments were performed on mouse embryos at embryonic day 9.5. Time-resolved 3D cardiodynamics clearly shows the heart structure in motion. We present analysis of cardiac wall movement and its velocity from the primitive atrium and ventricle. Our results suggest that the combination of ultrahigh-speed OCT imaging with live embryo culture could be a useful embryonic heart phenotyping approach for mouse mutants modeling human congenital heart diseases.

Impaired cardiac energy metabolism in embryos lacking adrenergic stimulation.

PubMed

Baker, Candice N; Gidus, Sarah A; Price, George F; Peoples, Jessica N R; Ebert, Steven N

2015-03-01

As development proceeds from the embryonic to fetal stages, cardiac energy demands increase substantially, and oxidative phosphorylation of ADP to ATP in mitochondria becomes vital. Relatively little, however, is known about the signaling mechanisms regulating the transition from anaerobic to aerobic metabolism that occurs during the embryonic period. The main objective of this study was to test the hypothesis that adrenergic hormones provide critical stimulation of energy metabolism during embryonic/fetal development. We examined ATP and ADP concentrations in mouse embryos lacking adrenergic hormones due to targeted disruption of the essential dopamine β-hydroxylase (Dbh) gene. Embryonic ATP concentrations decreased dramatically, whereas ADP concentrations rose such that the ATP/ADP ratio in the adrenergic-deficient group was nearly 50-fold less than that found in littermate controls by embryonic day 11.5. We also found that cardiac extracellular acidification and oxygen consumption rates were significantly decreased, and mitochondria were significantly larger and more branched in adrenergic-deficient hearts. Notably, however, the mitochondria were intact with well-formed cristae, and there was no significant difference observed in mitochondrial membrane potential. Maternal administration of the adrenergic receptor agonists isoproterenol or l-phenylephrine significantly ameliorated the decreases in ATP observed in Dbh-/- embryos, suggesting that α- and β-adrenergic receptors were effective modulators of ATP concentrations in mouse embryos in vivo. These data demonstrate that adrenergic hormones stimulate cardiac energy metabolism during a critical period of embryonic development. Copyright © 2015 the American Physiological Society.

Heart Development, Diseases, and Regeneration　- New Approaches From Innervation, Fibroblasts, and Reprogramming.

PubMed

Ieda, Masaki

2016-09-23

It is well known that cardiac function is tightly controlled by neural activity; however, the molecular mechanism of cardiac innervation during development and the relationship with heart disease remain undetermined. My work has revealed the molecular networks that govern cardiac innervation and its critical roles in heart diseases such as silent myocardial ischemia and arrhythmias. Cardiomyocytes proliferate during embryonic development, but lose their proliferative capacity after birth. Cardiac fibroblasts are a major source of cells during fibrosis and induce cardiac hypertrophy after myocardial injury in the adult heart. Despite the importance of fibroblasts in the adult heart, the role of fibroblasts in embryonic heart development was previously not determined. I demonstrated that cardiac fibroblasts play important roles in myocardial growth and cardiomyocyte proliferation during embryonic development, and I identified key paracrine factors and signaling pathways. In contrast to embryonic cardiomyocytes, adult cardiomyocytes have little regenerative capacity, leading to heart failure and high mortality rates after myocardial infarction. Leveraging the knowledge of developmental biology, I identified cardiac reprogramming factors that can directly convert resident cardiac fibroblasts into cardiomyocytes for heart regeneration. These findings greatly improved our understanding of heart development and diseases, and provide a new strategy for heart regenerative therapy. (Circ J 2016; 80: 2081-2088).

Longitudinal Effects of Embryonic Exposure to Cocaine on Morphology, Cardiovascular Physiology, and Behavior in Zebrafish.

PubMed

Mersereau, Eric J; Boyle, Cody A; Poitra, Shelby; Espinoza, Ana; Seiler, Joclyn; Longie, Robert; Delvo, Lisa; Szarkowski, Megan; Maliske, Joshua; Chalmers, Sarah; Darland, Diane C; Darland, Tristan

2016-05-31

A sizeable portion of the societal drain from cocaine abuse results from the complications of in utero drug exposure. Because of challenges in using humans and mammalian model organisms as test subjects, much debate remains about the impact of in utero cocaine exposure. Zebrafish offer a number of advantages as a model in longitudinal toxicology studies and are quite sensitive physiologically and behaviorally to cocaine. In this study, we have used zebrafish to model the effects of embryonic pre-exposure to cocaine on development and on subsequent cardiovascular physiology and cocaine-induced conditioned place preference (CPP) in longitudinal adults. Larval fish showed a progressive decrease in telencephalic size with increased doses of cocaine. These treated larvae also showed a dose dependent response in heart rate that persisted 24 h after drug cessation. Embryonic cocaine exposure had little effect on overall health of longitudinal adults, but subtle changes in cardiovascular physiology were seen including decreased sensitivity to isoproterenol and increased sensitivity to cocaine. These longitudinal adult fish also showed an embryonic dose-dependent change in CPP behavior, suggesting an increased sensitivity. These studies clearly show that pre-exposure during embryonic development affects subsequent cocaine sensitivity in longitudinal adults.

Modulation of ovarian steroidogenesis by adiponectin during delayed embryonic development of Cynopterus sphinx.

PubMed

Anuradha; Krishna, Amitabh

2014-09-01

The aim of present study was to evaluate role of adiponectin in ovarian steroidogenesis during delayed embryonic development of Cynopterus sphinx. This study showed significantly low circulating adiponectin level and a decline in expression of adiponectin receptor 1 (AdipoR1) in the ovary during the period of delayed embryonic development as compared with the normal development. The adiponectin treatment in vivo during the period of delayed development caused significantly increased in circulating progesterone and estradiol levels together with increased expression of AdipoR1 in the ovary. The in vitro study confirmed the stimulatory effect of adiponectin on progesterone synthesis. Both in vivo and in vitro studies showed that the effects of adiponectin on ovarian steroidogenesis were mediated through increased expression of luteinizing hormone-receptor, steroidogenic acute regulatory protein and 3β-hydroxyl steroid dehydrogenase enzyme. The adiponectin treatment may also promote progesterone synthesis by modulating ovarian angiogenesis, cell survival and rate of apoptosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Live dynamic imaging and analysis of developmental cardiac defects in mouse models with optical coherence tomography

NASA Astrophysics Data System (ADS)

Lopez, Andrew L.; Wang, Shang; Garcia, Monica; Valladolid, Christian; Larin, Kirill V.; Larina, Irina V.

2015-03-01

Understanding mouse embryonic development is an invaluable resource for our interpretation of normal human embryology and congenital defects. Our research focuses on developing methods for live imaging and dynamic characterization of early embryonic development in mouse models of human diseases. Using multidisciplinary methods: optical coherence tomography (OCT), live mouse embryo manipulations and static embryo culture, molecular biology, advanced image processing and computational modeling we aim to understand developmental processes. We have developed an OCT based approach to image live early mouse embryos (E8.5 - E9.5) cultured on an imaging stage and visualize developmental events with a spatial resolution of a few micrometers (less than the size of an individual cell) and a frame rate of up to hundreds of frames per second and reconstruct cardiodynamics in 4D (3D+time). We are now using these methods to study how specific embryonic lethal mutations affect cardiac morphology and function during early development.

Embryonic development and inviability phenotype of chicken-Japanese quail F1 hybrids

PubMed Central

Ishishita, Satoshi; Kinoshita, Keiji; Nakano, Mikiharu; Matsuda, Yoichi

2016-01-01

Interspecific hybrid incompatibility, including inviability and sterility, is important in speciation; however, its genetic basis remains largely unknown in vertebrates. Crosses between male chickens and female Japanese quails using artificial insemination can generate intergeneric hybrids; however, the hatching rate is low, and hatched hybrids are only sterile males. Hybrid development is arrested frequently during the early embryonic stages, and the sex ratio of living embryos is male-biased. However, the development and sex ratio of hybrid embryos have not been comprehensively analyzed. In the present study, we observed delayed embryonic development of chicken-quail hybrids during the early stage, compared with that of chickens and quails. The survival rate of hybrids decreased markedly during the blastoderm-to-pre-circulation stage and then decreased gradually through the subsequent stages. Hybrid females were observed at more than 10 d of incubation; however, the sex ratio of hybrids became male-biased from 10 d of incubation. Severely malformed embryos were observed frequently in hybrids. These results suggest that developmental arrest occurs at various stages in hybrid embryos, including a sexually non-biased arrest during the early stage and a female-biased arrest during the late stage. We discuss the genetic basis for hybrid inviability and its sex bias. PMID:27199007

Influence of cosmic radiation and/or microgravity on development of Carausius morosus.

PubMed

Reitz, G; Bucker, H; Facius, R; Horneck, G; Graul, E H; Berger, H; Ruther, W; Heinrich, W; Beaujean, R; Enge, W; Alpatov, A M; Ushakov, I A; Zachvatkin YuA; Mesland, D A

1989-01-01

Eggs of Carausius morosus were exposed to spaceflight conditions in two spaceflight missions, the German 7 day Spacelab Mission D1 and the Soviet 12.56 day Biosatellite Mission "COSMOS 1887". During spaceflight the eggs continued their development. Eggs of five different ages representing different sensitivity to radiation and different capacity to regeneration were used to investigate the influence of cosmic radiation and/or microgravity on insect development. Using the Biostack concept--eggs in monolayers sandwiched between nuclear track detectors--and the 1 g reference centrifuge of BIORACK in D1 we were able to separate effects of heavy ions of the cosmic radiation from microgravity effects and also from combined effects of these two factors in space. After retrieval, hatching rates, embryonic and larval growth kinetics and anomaly frequencies were determined. Microgravity leads to a reduced hatching rate of eggs exposed in the early stages of development. Hatching was normal in eggs which were exposed on the 1 g reference centrifuge. Hits by heavy ions caused body anomalies. The combined action of heavy ions and microgravity resulted in an unexpectedly high frequency of anomalies. These results obtained from the Spacelab Mission D1, were confirmed in an experiment onboard of COSMOS 1887. In addition to the previous analysis, embryonic development before hatching was followed which showed no major difference between flight and the ground control specimens. Since a reconfirmation of reduced hatching rates was observed in COSMOS 1887, too, the above results suggest some microgravity induced functional impairment of the hatching activity, rather than blockage in embryonic development.

Effect of tidal overwash on the embryonic development of leatherback turtles in French Guiana.

PubMed

Caut, Stéphane; Guirlet, Elodie; Girondot, Marc

2010-05-01

In marine turtles, the physical conditions experienced by eggs during incubation affect embryonic development. In the leatherback, hatching success is known to be low in relation to other marine turtles as a result of high embryonic mortality. Moreover, the hatching success on Yalimapo in French Guiana, one major nesting beach for this species, is lower compared to other nesting sites. We assessed the rate of leatherback turtle embryonic mortality in order to investigate the tolerance of leatherback turtle clutches laid on Yalimapo beach to tidal overwash, and we highlight causes of poor hatching success. Of the 89 nests studied, 27 were overlapped by tide at least once during the incubation period (of which five nests were lost by erosion). The hatching success was on average significantly lower in overwashed nests than in non-overwashed, highlighting the existence of embryonic developmental arrest linked to tidal inundation. The stages of developmental arrest and their proportion are linked with time, frequency and level of overwash events. In the context of global warming and associated sea-level rise, understanding the detrimental effect of tidal inundation on the development of marine turtle nests is of interest in nesting sites where turtles are likely to be forced to nest closer to the tide line, thus exposing their nests to greater risk of nest overlap with sea and tidal inundation. Copyright 2009 Elsevier Ltd. All rights reserved.

Deep RNA sequencing of pectoralis muscle transcriptomes during late-term embryonic to neonatal development in indigenous Chinese duck breeds

PubMed Central

Tao, Zhiyun; Liu, Hongxiang; Xu, Wenjuan; Zhang, Shuangjie; Li, Huifang

2017-01-01

Pectoral muscle (PM) comprises an important component of overall meat mass in ducks. However, PM has shown arrested or even reduced growth during late embryonic development, and the molecular mechanisms underlying PM growth during the late embryonic to neonatal period in ducks have not been addressed. In this study, we characterized potential candidate genes and signaling pathways related to PM development using RNA sequencing of PM samples selected at embryonic days (E) 21 and 27 and 5 days post-hatch (dph) in two duck breeds (Gaoyou and Jinding ducks). A total of 393 differentially expressed genes (DEGs) were identified, which showed higher or lower expression levels at E27 compared with E21 and 5 dph, reflecting the pattern of PM growth rates. Among these, 43 DEGs were common to all three time points in both duck breeds. These DEGs may thus be involved in regulating this developmental process. Specifically, KEGG pathway analysis of the 393 DEGs showed that genes involved with different metabolism pathways were highly expressed, while genes involved with cell cycle pathways showed lower expression levels at E27. These DEGs may thus be involved in the mechanisms responsible for the phenomenon of static or decreased breast muscle growth in duck breeds during the late embryonic period. These results increase the available genetic information for ducks and provide valuable resources for analyzing the mechanisms underlying the process of PM development. PMID:28771592

Deep RNA sequencing of pectoralis muscle transcriptomes during late-term embryonic to neonatal development in indigenous Chinese duck breeds.

PubMed

Zhu, Chunhong; Song, Weitao; Tao, Zhiyun; Liu, Hongxiang; Xu, Wenjuan; Zhang, Shuangjie; Li, Huifang

2017-01-01

Pectoral muscle (PM) comprises an important component of overall meat mass in ducks. However, PM has shown arrested or even reduced growth during late embryonic development, and the molecular mechanisms underlying PM growth during the late embryonic to neonatal period in ducks have not been addressed. In this study, we characterized potential candidate genes and signaling pathways related to PM development using RNA sequencing of PM samples selected at embryonic days (E) 21 and 27 and 5 days post-hatch (dph) in two duck breeds (Gaoyou and Jinding ducks). A total of 393 differentially expressed genes (DEGs) were identified, which showed higher or lower expression levels at E27 compared with E21 and 5 dph, reflecting the pattern of PM growth rates. Among these, 43 DEGs were common to all three time points in both duck breeds. These DEGs may thus be involved in regulating this developmental process. Specifically, KEGG pathway analysis of the 393 DEGs showed that genes involved with different metabolism pathways were highly expressed, while genes involved with cell cycle pathways showed lower expression levels at E27. These DEGs may thus be involved in the mechanisms responsible for the phenomenon of static or decreased breast muscle growth in duck breeds during the late embryonic period. These results increase the available genetic information for ducks and provide valuable resources for analyzing the mechanisms underlying the process of PM development.

Beta-hydroxybutyrate increases reactive oxygen species in late but not in early postimplantation embryonic cells in vitro.

PubMed

Forsberg, H; Eriksson, U J; Melefors, O; Welsh, N

1998-02-01

Embryonic dysmorphogenesis has been blocked by antioxidant treatment in vivo and in vitro, suggesting that embryonic excess of reactive oxygen species (ROS) has a role in the teratogenic process of diabetic pregnancy. We report that the basal levels of ROS in dispersed rat embryonic cells in vitro, as determined by fluorescence of dichlorofluorescein (DCF), were not different in cells from control and diabetic pregnancy at day 10 or 12. Beta-hydroxybutyrate (beta-HB) and succinic acid monomethyl ester both augmented DCF fluorescence in cells from day 12 embryos of normal and diabetic rats but not from day 10 embryos. Cells of day 10 and day 12 embryos from normal and diabetic rats responded to increasing glucose concentrations with a dosage-dependent alleviation of DCF fluorescence. Day 10 embryonic cells exhibited high glucose utilization rates and high pentose phosphate shunt rates, but low mitochondrial oxidation rates. Moreover, in vitro culture of embryos between gestational days 9 and 10 in the presence of 20% oxygen induced an increased and glucose-sensitive oxidation of glucose compared with embryos not cultured in vitro. At gestation day 12, however, pentose phosphate shunt rates showed a decrease, whereas the mitochondrial beta-HB oxidation rates were increased compared with those at gestation day 10. This was paralleled by a lower expression of glucose 6-phosphate dehydrogenase- and phosphofructokinase-mRNA levels at day 12 than at day 10. On the other hand, H-ferritin mRNA expression at day 12 was high compared with day 10. None of the mRNA species investigated were affected by the diabetic state of the mother. It was concluded that beta-HB-induced stimulation of mitochondrial oxidative events may lead to the generation of ROS at gestational day 12, but probably not at day 10, when only a minute amount of mitochondrial activity occurs. Thus our results do not support the notion of diabetes-induced mitochondrial oxidative stress before the development of a placental supply of oxygen.

Higher growth rate and gene expression in male zebra finch embryos are independent of manipulation of maternal steroids in the eggs.

PubMed

Lutyk, Dorota; Tagirov, Makhsud; Drobniak, Szymon; Rutkowska, Joanna

2017-12-01

Sexual dimorphism in prenatal development is widespread among vertebrates, including birds. Its mechanism remains unclear, although it has been attributed to the effect of maternal steroid hormones. The aim of this study was to investigate how increased levels of steroid hormones in the eggs influence early embryonic development of male and female offspring. We also asked whether maternal hormones take part in the control of sex-specific expression of the genes involved in prenatal development. We experimentally manipulated hormones' concentrations in the egg yolk by injecting zebra finch females prior to ovulation with testosterone or corticosterone. We assessed growth rate and expression levels of CDK7, FBP1 and GHR genes in 37h-old embryos. We found faster growth and higher expression of two studied genes in male compared to female embryos. Hormonal treatment, despite clearly differentiating egg steroid levels, had no effect on the sex-specific pattern of the embryonic gene expression, even though we confirmed expression of receptors of androgens and glucocorticoids at such an early stage of development. Thus, our study shows high stability of the early sex differences in the embryonic development before the onset of sexual differentiation and indicates their independence of maternal hormones in the egg. Copyright © 2017 Elsevier Inc. All rights reserved.

Aspects of embryonic and larval development in bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix

USGS Publications Warehouse

George, Amy E.; Chapman, Duane C.

2013-01-01

As bighead carp Hypophthalmichthys nobilis and silver carp H. molitrix (the bigheaded carps) are poised to enter the Laurentian Great Lakes and potentially damage the region’s economically important fishery, information on developmental rates and behaviors of carps is critical to assessing their ability to establish sustainable populations within the Great Lakes basin. In laboratory experiments, the embryonic and larval developmental rates, size, and behaviors of bigheaded carp were tracked at two temperature treatments, one “cold” and one “warm”. Developmental rates were computed using previously described stages of development and the cumulative thermal unit method. Both species have similar thermal requirements, with a minimum developmental temperature for embryonic stages of 12.1° C for silver carp and 12.9° C for bighead carp, and 13.3° C for silver carp larval stages and 13.4° C for bighead carp larval stages. Egg size differed among species and temperature treatments, as egg size was larger in bighead carp, and “warm" temperature treatments. The larvae started robust upwards vertical swimming immediately after hatching, interspersed with intervals of sinking. Vertical swimming tubes were used to measure water column distribution, and ascent and descent rates of vertically swimming fish. Water column distribution and ascent and descent rates changed with ontogeny. Water column distribution also showed some diel periodicity. Developmental rates, size, and behaviors contribute to the drift distance needed to fulfill the early life history requirements of bigheaded carps and can be used in conjunction with transport information to assess invasibility of a river.

Effects of two strobilurins (azoxystrobin and picoxystrobin) on embryonic development and enzyme activities in juveniles and adult fish livers of zebrafish (Danio rerio).

PubMed

Jia, Wei; Mao, Liangang; Zhang, Lan; Zhang, Yanning; Jiang, Hongyun

2018-09-01

Azoxystrobin and picoxystrobin are two primary strobilurin fungicides used worldwide. This study was conducted to test their effects on embryonic development and the activity of several enzyme in the zebrafish (Danio rerio). After fish eggs were separately exposed to azoxystrobin and picoxystrobin from 24 to 144 h post fertilization (hpf), the mortality, hatching, and teratogenetic rates were measured. Additionally, effects of azoxystrobin and picoxystrobin on activities of three important antioxidant enzymes [catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD)] and two primary detoxification enzymes [carboxylesterase (CarE) and glutathione S-transferase (GST)] and malondialdehyde (MDA) content in zebrafish larvae (96 h) and livers of adult zebrafish of both sexes were also assessed for potential toxicity mechanisms. Based on the embryonic development test results, the mortality, hatching, and teratogenetic rates of eggs treated with azoxystrobin and picoxystrobin all showed significant dose- and time-dependent effects, and the 144-h LC 50 values of azoxystrobin and picoxystrobin were 1174.9 and 213.8 μg L -1 , respectively. In the larval zebrafish (96 h) test, activities of CAT, POD, CarE, and GST and MDA content in azoxystrobin and picoxystrobin-treated zebrafish larvae increased significantly with concentrations of the pesticides compared with those in the control. We further revealed that azoxystrobin and picoxystrobin exposure both caused significant oxidative stress in adult fish livers and the changes differed between the sexes. Our results indicated that picoxystrobin led to higher embryonic development toxicity and oxidative stress than azoxystrobin in zebrafish and the male zebrafish liver had stronger ability to detoxify than that of the females. Copyright © 2018 Elsevier Ltd. All rights reserved.

Variation in maternal effects and embryonic development rates among passerine species

USGS Publications Warehouse

Martin, T.E.; Schwabl, H.

2008-01-01

Embryonic development rates are reflected by the length of incubation period in birds, and these vary substantially among species within and among geographical regions. The incubation periods are consistently shorter in North America (Arizona study site) than in tropical (Venezuela) and subtropical (Argentina) South America based on the study of 83 passerine species in 17 clades. Parents, mothers in particular, may influence incubation periods and resulting offspring quality through proximate pathways, while variation in maternal strategies among species can result from selection by adult and offspring mortality. Parents of long-lived species, as is common in the tropics and subtropics, may be under selection to minimize costs to themselves during incubation. Indeed, time spent incubating is often lower in the tropical and subtropical species than the related north temperate species, causing cooler average egg temperatures in the southern regions. Decreased egg temperatures result in longer incubation periods and reflect a cost imposed on offspring by parents because energy cost to the embryo and risk of offspring predation are both increased. Mothers may adjust egg size and constituents as a means to partially offset such costs. For example, reduced androgen concentrations in egg yolks may slow development rates, but may enhance offspring quality through physiological trade-offs that may be particularly beneficial in longer-lived species, as in the tropics and subtropics. We provide initial data to show that yolks of tropical birds contain substantially lower concentrations of growth-promoting androgens than north temperate relatives. Thus, maternal (and parental) effects on embryonic development rates may include contrasting and complementary proximate influences on offspring quality and deserve further field study among species. ?? 2007 The Royal Society.

Variation in maternal effects and embryonic development rates among passerine species.

PubMed

Martin, Thomas E; Schwabl, Hubert

2008-05-12

Embryonic development rates are reflected by the length of incubation period in birds, and these vary substantially among species within and among geographical regions. The incubation periods are consistently shorter in North America (Arizona study site) than in tropical (Venezuela) and subtropical (Argentina) South America based on the study of 83 passerine species in 17 clades. Parents, mothers in particular, may influence incubation periods and resulting offspring quality through proximate pathways, while variation in maternal strategies among species can result from selection by adult and offspring mortality. Parents of long-lived species, as is common in the tropics and subtropics, may be under selection to minimize costs to themselves during incubation. Indeed, time spent incubating is often lower in the tropical and subtropical species than the related north temperate species, causing cooler average egg temperatures in the southern regions. Decreased egg temperatures result in longer incubation periods and reflect a cost imposed on offspring by parents because energy cost to the embryo and risk of offspring predation are both increased. Mothers may adjust egg size and constituents as a means to partially offset such costs. For example, reduced androgen concentrations in egg yolks may slow development rates, but may enhance offspring quality through physiological trade-offs that may be particularly beneficial in longer-lived species, as in the tropics and subtropics. We provide initial data to show that yolks of tropical birds contain substantially lower concentrations of growth-promoting androgens than north temperate relatives. Thus, maternal (and parental) effects on embryonic development rates may include contrasting and complementary proximate influences on offspring quality and deserve further field study among species.

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.

Selected sperm traits are simultaneously altered after scrotal heat stress and play specific roles in in vitro fertilization and embryonic development.

PubMed

Lucio, Aline C; Alves, Benner G; Alves, Kele A; Martins, Muller C; Braga, Lucas S; Miglio, Luisa; Alves, Bruna G; Silva, Thiago H; Jacomini, José O; Beletti, Marcelo E

2016-09-01

Improvements in the estimation of male fertility indicators require advances in laboratory tests for sperm assessment. The aims of the present work were (1) to apply a multivariate analysis to examine sperm set of alterations and interactions and (2) to evaluate the importance of sperm parameters on the outcome of standard IVF and embryonic development. Bulls (n = 3) were subjected to scrotal insulation, and ejaculates were collected before (preinsulation = Day 0) and through 56 days (Days 7, 14, 21, 28, 35, 42, 49, and 56) of the experimental period. Sperm head morphometry and chromatin variables were assessed by a computational image analysis, and IVF was performed. Scrotal heat stress induced alterations in all evaluated sperm head features, as well as cleavage and blastocyst rates. A principal component analysis revealed three main components (factors) that represented almost 89% of the cumulative variance. In addition, an association of factor scores with cleavage (factor 1) and blastocyst (factor 3) rates was observed. In conclusion, several sperm traits were simultaneously altered as a result of a thermal insult. These sperm traits likely play specific roles in IVF and embryonic development. Copyright © 2016 Elsevier Inc. All rights reserved.

Aspp2 negatively regulates body growth but not developmental timing by modulating IRS signaling in zebrafish embryos.

PubMed

Liu, Chengdong; Luan, Jing; Bai, Yan; Li, Yun; Lu, Ling; Liu, Yunzhang; Hakuno, Fumihiko; Takahashi, Shin-Ichiro; Duan, Cunming; Zhou, Jianfeng

2014-02-01

The growth and developmental rate of developing embryos and fetus are tightly controlled and coordinated to maintain proper body shape and size. The insulin receptor substrate (IRS) proteins, key intracellular transducers of insulin and insulin-like growth factor signaling, play essential roles in the regulation of growth and development. A short isoform of apoptosis-stimulating protein of p53 2 (ASPP2) was recently identified as a binding partner of IRS-1 and IRS-2 in mammalian cells in vitro. However, it is unclear whether ASPP2 plays any role in vertebrate embryonic growth and development. Here, we show that zebrafish Aspp2a and Aspp2b negatively regulate embryonic growth without affecting developmental rate. Human ASPP2 had similar effects on body growth in zebrafish embryos. Aspp2a and 2b inhibit Akt signaling. This inhibition was reversed by coinjection of myr-Akt1, a constitutively active form of Akt1. Zebrafish Aspp2a and Aspp2b physically bound with Irs-1, and the growth inhibitory effects of ASPP2/Aspp2 depend on the presence of their ankyrin repeats and SH3 domains. These findings uncover a novel role of Aspp2 in regulating vertebrate embryonic growth. Copyright © 2013 Elsevier Inc. All rights reserved.

A new method of estimating thermal performance of embryonic development rate yields accurate prediction of embryonic age in wild reptile nests.

PubMed

Rollinson, Njal; Holt, Sarah M; Massey, Melanie D; Holt, Richard C; Nancekivell, E Graham; Brooks, Ronald J

2018-05-01

Temperature has a strong effect on ectotherm development rate. It is therefore possible to construct predictive models of development that rely solely on temperature, which have applications in a range of biological fields. Here, we leverage a reference series of development stages for embryos of the turtle Chelydra serpentina, which was described at a constant temperature of 20 °C. The reference series acts to map each distinct developmental stage onto embryonic age (in days) at 20 °C. By extension, an embryo taken from any given incubation environment, once staged, can be assigned an equivalent age at 20 °C. We call this concept "Equivalent Development", as it maps the development stage of an embryo incubated at a given temperature to its equivalent age at a reference temperature. In the laboratory, we used the concept of Equivalent Development to estimate development rate of embryos of C. serpentina across a series of constant temperatures. Using these estimates of development rate, we created a thermal performance curve measured in units of Equivalent Development (TPC ED ). We then used the TPC ED to predict developmental stage of embryos in several natural turtle nests across six years. We found that 85% of the variation of development stage in natural nests could be explained. Further, we compared the predictive accuracy of the model based on the TPC ED to the predictive accuracy of a degree-day model, where development is assumed to be linearly related to temperature and the amount of accumulated heat is summed over time. Information theory suggested that the model based on the TPC ED better describes variation in developmental stage in wild nests than the degree-day model. We suggest the concept of Equivalent Development has several strengths and can be broadly applied. In particular, studies on temperature-dependent sex determination may be facilitated by the concept of Equivalent Development, as development age maps directly onto the developmental series of the organism, allowing critical periods of sex determination to be delineated without invasive sampling, even under fluctuating temperature. Copyright © 2018 Elsevier Ltd. All rights reserved.

Paternal identity impacts embryonic development for two species of freshwater fish.

PubMed

Siddique, Mohammad Abdul Momin; Linhart, Otomar; Krejszeff, Sławomir; Żarski, Daniel; Pitcher, Trevor E; Politis, Sebastian Nikitas; Butts, Ian Anthony Ernest

2017-05-01

Paternal, compared to maternal, contributions were believed to have only a limited influence on embryonic development and larval fitness traits in fishes. Therefore, the perspective of male influence on early life history traits has come under scrutiny. This study was conducted to determine parental effects on the rate of eyed embryos of Ide Leuciscus idus and Northern pike Esox lucius. Five sires and five dams from each species were crossed using a quantitative genetic breeding design and the resulting 25 sib groups of each species were reared to the embryonic eyed stage. We then partition variation in embryonic phenotypic performance to maternal, paternal, and parental interactions using the Restricted Maximum Likelihood (REML) model. Results showed that paternal, maternal, and the paternal×maternal interaction terms were highly significant for both species; clearly demonstrating that certain family combinations were more compatible than others. Paternal effects explained 20.24% of the total variance, which was 2-fold higher than the maternal effects (10.73%) in Ide, while paternal effects explained 18.9% of the total variance, which was 15-fold higher than the maternal effects (1.3%) in Northern pike. Together, these results indicate that male effects are of major importance during embryonic development for these species. Furthermore, this study demonstrates that genetic compatibility between sires and dams plays an important role and needs to be taken into consideration for reproduction of these and likely other economically important fish species. Copyright © 2016 Elsevier Inc. All rights reserved.

Geographic variation in avian incubation periods and parental influences on embryonic temperature

USGS Publications Warehouse

Martin, T.E.; Auer, S.K.; Bassar, R.D.; Niklison, Alina M.; Lloyd, P.

2007-01-01

Theory predicts shorter embryonic periods in species with greater embryo mortality risk and smaller body size. Field studies of 80 passerine species on three continents yielded data that largely conflicted with theory; incubation (embryonic) periods were longer rather than shorter in smaller species, and egg (embryo) mortality risk explained some variation within regions, but did not explain larger differences in incubation periods among geographic regions. Incubation behavior of parents seems to explain these discrepancies. Bird embryos are effectively ectothermic and depend on warmth provided by parents sitting on the eggs to attain proper temperatures for development. Parents of smaller species, plus tropical and southern hemisphere species, commonly exhibited lower nest attentiveness (percent of time spent on the nest incubating) than larger and northern hemisphere species. Lower nest attentiveness produced cooler minimum and average embryonic temperatures that were correlated with longer incubation periods independent of nest predation risk or body size. We experimentally tested this correlation by swapping eggs of species with cool incubation temperatures with eggs of species with warm incubation temperatures and similar egg mass. Incubation periods changed (shortened or lengthened) as expected and verified the importance of egg temperature on development rate. Slower development resulting from cooler temperatures may simply be a cost imposed on embryos by parents and may not enhance offspring quality. At the same time, incubation periods of transferred eggs did not match host species and reflect intrinsic differences among species that may result from nest predation and other selection pressures. Thus, geographic variation in embryonic development may reflect more complex interactions than previously recognized. ?? 2007 The Author(s).

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.

Injurious effects of curcumin on maturation of mouse oocytes, fertilization and fetal development via apoptosis.

PubMed

Chen, Chia-Chi; Chan, Wen-Hsiung

2012-01-01

Curcumin, a common dietary pigment and spice, is a hydrophobic polyphenol derived from the rhizome of the herb Curcuma longa. Previously, we reported a cytotoxic effect of curcumin on mouse embryonic stem cells and blastocysts and its association with defects in subsequent development. In the present study, we further investigated the effects of curcumin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, curcumin induced a significant reduction in the rate of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with curcumin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments with an in vivo mouse model disclosed that consumption of drinking water containing 40 μM curcumin led to decreased oocyte maturation and in vitro fertilization as well as early embryonic developmental injury. Finally, pretreatment with a caspase-3-specific inhibitor effectively prevented curcumin-triggered injury effects, suggesting that embryo impairment by curcumin occurs mainly via a caspase-dependent apoptotic process.

[Embryotoxic and teratogenic effect of Pharmachem tetramisole].

PubMed

Stoianov, K; Todorov, S

1982-01-01

Studies were carried out to establish the effect of high rates of Tetramizol Pharmachim on the embryonal and fetal development in rats. The preparation was administered orally to pregnant animals under the form of a 1 per cent solution at the rate of 1/5 LD50 (=200 mg/kg), on the fourth and the thirteenth day of gestation. It was found that the amount of the preparation applied on the fourth day after conception took place led to rise of the preimplantation loss of embryos. The rate of the total embryonal mortality also rose. Accordingly, it was concluded that in high doses Tetramizol Pharmachim could produce an embryotoxic effect on rats. The application of the preparation later during pregnacy (the 13th day) did not have an adverse effect on the normal course of gestation. No abnormal effects were demonstrated on the growth and development of fetuses during all stages of investigation, which might point to the teratogenic action of Tetramizol.

Tetraploid Embryonic Stem Cells Maintain Pluripotency and Differentiation Potency into Three Germ Layers.

PubMed

Imai, Hiroyuki; Kano, Kiyoshi; Fujii, Wataru; Takasawa, Ken; Wakitani, Shoichi; Hiyama, Masato; Nishino, Koichiro; Kusakabe, Ken Takeshi; Kiso, Yasuo

2015-01-01

Polyploid amphibians and fishes occur naturally in nature, while polyploid mammals do not. For example, tetraploid mouse embryos normally develop into blastocysts, but exhibit abnormalities and die soon after implantation. Thus, polyploidization is thought to be harmful during early mammalian development. However, the mechanisms through which polyploidization disrupts development are still poorly understood. In this study, we aimed to elucidate how genome duplication affects early mammalian development. To this end, we established tetraploid embryonic stem cells (TESCs) produced from the inner cell masses of tetraploid blastocysts using electrofusion of two-cell embryos in mice and studied the developmental potential of TESCs. We demonstrated that TESCs possessed essential pluripotency and differentiation potency to form teratomas, which differentiated into the three germ layers, including diploid embryonic stem cells. TESCs also contributed to the inner cell masses in aggregated chimeric blastocysts, despite the observation that tetraploid embryos fail in normal development soon after implantation in mice. In TESCs, stability after several passages, colony morphology, and alkaline phosphatase activity were similar to those of diploid ESCs. TESCs also exhibited sufficient expression and localization of pluripotent markers and retained the normal epigenetic status of relevant reprogramming factors. TESCs proliferated at a slower rate than ESCs, indicating that the difference in genomic dosage was responsible for the different growth rates. Thus, our findings suggested that mouse ESCs maintained intrinsic pluripotency and differentiation potential despite tetraploidization, providing insights into our understanding of developmental elimination in polyploid mammals.

Gene expression dynamics during embryonic development in rainbow trout

USDA-ARS?s Scientific Manuscript database

The supply of maternal RNAs in fertilized egg and activation of embryonic genome during maternal-zygotic transition (MZT) are important for normal embryonic development. In order to identify genes and gene products that are essential in the regulation of embryonic development in rainbow trout, RNA-S...

Critical windows in embryonic development: Shifting incubation temperatures alter heart rate and oxygen consumption of Lake Whitefish (Coregonus clupeaformis) embryos and hatchlings.

PubMed

Eme, J; Mueller, C A; Manzon, R G; Somers, C M; Boreham, D R; Wilson, J Y

2015-01-01

Critical windows are periods of developmental susceptibility when the phenotype of an embryonic, juvenile or adult animal may be vulnerable to environmental fluctuations. Temperature has pervasive effects on poikilotherm physiology, and embryos are especially vulnerable to temperature shifts. To identify critical windows, we incubated whitefish embryos at control temperatures of 2°C, 5°C, or 8°C, and shifted treatments among temperatures at the end of gastrulation or organogenesis. Heart rate (fH) and oxygen consumption ( [Formula: see text] ) were measured across embryonic development, and [Formula: see text] was measured in 1-day old hatchlings. Thermal shifts, up or down, from initial incubation temperatures caused persistent changes in fH and [Formula: see text] compared to control embryos measured at the same temperature (2°C, 5°C, or 8°C). Most prominently, when embryos were measured at organogenesis, shifting incubation temperature after gastrulation significantly lowered [Formula: see text] or fH. Incubation at 2°C or 5°C through gastrulation significantly lowered [Formula: see text] (42% decrease) and fH (20% decrease) at 8°C, incubation at 2°C significantly lowered [Formula: see text] (40% decrease) and fH (30% decrease) at 5°C, and incubation at 5°C and 8°C significantly lowered [Formula: see text] at 2°C (27% decrease). Through the latter half of development, [Formula: see text] and fH in embryos were not different from control values for thermally shifted treatments. However, in hatchlings measured at 2°C, [Formula: see text] was higher in groups incubated at 5°C or 8°C through organogenesis, compared to 2°C controls (43 or 65% increase, respectively). Collectively, these data suggest that embryonic development through organogenesis represents a critical window of embryonic and hatchling phenotypic plasticity. This study presents an experimental design that identified thermally sensitive periods for fish embryos. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Long-range ordered vorticity patterns in living tissue induced by cell division

NASA Astrophysics Data System (ADS)

Rossen, Ninna S.; Tarp, Jens M.; Mathiesen, Joachim; Jensen, Mogens H.; Oddershede, Lene B.

2014-12-01

In healthy blood vessels with a laminar blood flow, the endothelial cell division rate is low, only sufficient to replace apoptotic cells. The division rate significantly increases during embryonic development and under halted or turbulent flow. Cells in barrier tissue are connected and their motility is highly correlated. Here we investigate the long-range dynamics induced by cell division in an endothelial monolayer under non-flow conditions, mimicking the conditions during vessel formation or around blood clots. Cell divisions induce long-range, well-ordered vortex patterns extending several cell diameters away from the division site, in spite of the system’s low Reynolds number. Our experimental results are reproduced by a hydrodynamic continuum model simulating division as a local pressure increase corresponding to a local tension decrease. Such long-range physical communication may be crucial for embryonic development and for healing tissue, for instance around blood clots.

The relationship of parthenogenesis in virgin Chinese Painted quail (Coturnix chinensis) hens with embryonic mortality and hatchability following mating.

PubMed

Parker, H M; Kiess, A S; Robertson, M L; Wells, J B; McDaniel, C D

2012-06-01

Unfertilized chicken, turkey, and quail eggs are capable of developing embryos by parthenogenesis. However, it is unknown if the physiological mechanisms regulating parthenogenesis in virgin hens may actually work against fertilization, embryonic development, and hatchability of eggs from these same hens following mating. Additionally, because most parthenogenic development closely resembles early embryonic mortality in fertilized eggs during the first 2 to 3 d of incubation, it is possible that many unhatched eggs classified as containing early embryonic mortality may actually be unfertilized eggs that contain parthenogens. Therefore, the objective of this study was to examine the relationship of parthenogenesis before mating with embryonic development and hatchability characteristics after mating. Based upon their ability to produce unfertilized eggs that contain parthenogens, 372 virgin Chinese Painted quail hens were divided into 7 groups, according to their incidence of parthenogenesis: 0, 10, 20, 30, 40, 50, and greater than 50% parthenogenesis. Males were then placed with these hens so that fertility, embryonic mortality, and hatchability could be evaluated for each hen. Hatchability of eggs set, hatchability of fertile eggs, and late embryonic mortality declined dramatically as the incidence of parthenogenesis increased. On the other hand, early embryonic mortality increased as parthenogenesis increased. Fertility was not different across the 7 parthenogenesis hen groups, perhaps because unfertilized eggs that exhibited parthenogenesis resembled and were therefore classified as early embryonic mortality. In conclusion, virgin quail hens that exhibit parthenogenesis appear to have impaired embryonic development and hatchability following mating. Additional sperm-egg interaction and embryonic research is needed to determine if a large portion of the early embryonic mortality experienced by mated hens that exhibit parthenogenesis as virgin hens is in fact embryonic development in unfertilized eggs.

Altered glucose transport to utero-embryonic unit in relation to delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx.

PubMed

Arnab, Banerjee; Amitabh, Krishna

2011-02-10

The aim of this study was to compare the changes in concentration of glucose and glucose transporters (GLUTs) in the utero-embryonic unit, consisting of decidua, trophoblast and embryo, during delayed and non-delayed periods to understand the possible cause of delayed embryonic development in Cynopterus sphinx. The results showed a significantly decreased concentration of glucose in the utero-embryonic unit due to decline in the expression of insulin receptor (IR) and GLUT 3, 4 and 8 proteins in the utero-embryonic unit during delayed period. The in vitro study showed suppressive effect of insulin on expression of GLUTs 4 and 8 in the utero-embryonic unit and a significant positive correlation between the decreased amount of glucose consumed by the utero-embryonic unit and decreased expression of GLUTs 4 (r=0.99; p<0.05) and 8 (r=0.98; p<0.05). The in vivo study showed expression of IR and GLUT 4 proteins in adipose tissue during November suggesting increased transport of glucose to adipose tissue for adipogenesis. This study showed increased expression of HSL and OCTN2 and increased availability of l-carnitine to utero-embryonic unit suggesting increased transport of fatty acid to utero-embryonic unit during the period of delayed embryonic development. Hence it appears that due to increased transport of glucose for adipogenesis prior to winter, glucose utilization by utero-embryonic unit declines and this may be responsible for delayed embryonic development in C. sphinx. Increased supply of fatty acid to the delayed embryo may be responsible for its survival under low glucose condition but unable to promote embryonic development in C. sphinx. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

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.

Comparative effects of in ovo exposure to sodium perchlorate on development, growth, metabolism, and thyroid function in the common snapping turtle (Chelydra serpentina) and red-eared slider (Trachemys scripta elegans).

PubMed

Eisenreich, Karen M; Dean, Karen M; Ottinger, Mary Ann; Rowe, Christopher L

2012-11-01

Perchlorate is a surface and groundwater contaminant found in areas associated with munitions and rocket manufacturing and use. It is a thyroid-inhibiting compound, preventing uptake of iodide by the thyroid gland, ultimately reducing thyroid hormone production. As thyroid hormones influence metabolism, growth, and development, perchlorate exposure during the embryonic period may impact embryonic traits that ultimately influence hatchling performance. We topically exposed eggs of red-eared sliders (Trachemys scripta) and snapping turtles (Chelydra serpentina) to 200 and 177 μg/g of perchlorate (as NaClO(4)), respectively, to determine impacts on glandular thyroxine concentrations, embryonic growth and development, and metabolic rates of hatchlings for a period of 2 months post-hatching. In red-eared sliders, in ovo perchlorate exposure delayed hatching, increased external yolk size at hatching, increased hatchling mortality, and reduced total glandular thyroxine concentrations in hatchlings. In snapping turtles, hatching success and standard metabolic rates were reduced, liver and thyroid sizes were increased, and total glandular thyroxine concentrations in hatchlings were reduced after exposure to perchlorate. While both species were negatively affected by exposure, impacts on red-eared sliders were most severe, suggesting that the slider may be a more sensitive sentinel species for studying effects of perchlorate exposure to turtles. Copyright © 2012 Elsevier Inc. All rights reserved.

Effects of Deepwater Horizon crude oil exposure, temperature and developmental stage on oxygen consumption of embryonic and larval mahi-mahi (Coryphaena hippurus).

PubMed

Pasparakis, Christina; Mager, Edward M; Stieglitz, John D; Benetti, Daniel; Grosell, Martin

2016-12-01

The timing and location of the 2010 Deepwater Horizon (DWH) incident within the Gulf of Mexico resulted in crude oil exposure of many commercially and ecologically important fish species, such as mahi-mahi (Coryphaena hippurus), during the sensitive early life stages. Previous research has shown that oil exposure during the embryonic stage of predatory pelagic fish reduces cardiac function - a particularly important trait for fast-swimming predators with high aerobic demands. However, it is unclear whether reductions in cardiac function translate to impacts on oxygen consumption in these developing embryos and larvae. A 24-channel optical-fluorescence oxygen-sensing system for high-throughput respiration measurements was used to investigate the effects of oil exposure, temperature and developmental stage on oxygen consumption rates in embryonic and larval mahi-mahi. Oil-exposed developing mahi-mahi displayed increased oxygen consumption, despite clear cardiac deformities and bradycardia, confirming oxygen uptake and delivery from a source other than the circulatory system. In addition to metabolic rate measurements, nitrogenous waste excretion was measured to test the hypothesis that increased energy demand was fueled by protein catabolism. This is the first study to our knowledge that demonstrates increased energy demand and energy depletion in oil-exposed developing mahi-mahi. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of gravity on meiosis, fertilization and early embryogenesis in Caenorhabditis elegans

NASA Astrophysics Data System (ADS)

Sasagawa, Y.; Saito, Y.; Shimizu, M.; Ishioka, N.; Yamashita, M.; Takahashi, H.; Higashitani, A.

The embryonic development of the nematode Caenorhabditis elegans was examined under different gravitational conditions. The first cleavage plane in the 1-cell embryo was slid to some extent by re-orientation of liquid culture vessel, but the pattern and timing of cleavages were not affected. Under 100G of hypergravity condition with swing-centrifuge, the number of eggs laid from an adult hermaphrodite decreased and their hatching rate was drastically reduced. On the other hand, the embryonic development after fertilization normally occurred and grew to adulthood at more than 100G of hypergravity. When the adult hermaphrodites cultured under 100G of hypergravity transferred to a ground condition (1G), the newly fertilized embryos normally developed and their hatching rate was fully recovered. These results indicated that the reproductive process except spermatogenesis, oogenesis and embryogenesis after fertilization is impaired under 100G of hypergravity condition, and the effect is transient. Namely, the fertilization process including meiotic divisions I and II is sensitive to hypergravity in the nematode C. elegans.

Embryogenesis and oxygen consumption in benthic egg clutches of a tropical clownfish, Amphiprion melanopus (Pomacentridae).

PubMed

Green, Bridget S

2004-05-01

Variation in size at hatching is common in demersal spawning organisms, suggesting that processes during embryonic development may be critical in determining growth and development. To examine critical periods during embryonic development in the demersal spawning reef fish Amphiprion melanopus, the rate of oxygen consumption within an egg clutch was compared to morphological changes in the embryos. Oxygen consumption was least on day 1 of development where organ differentiation had not begun (mean 1.73+/-0.34x10(-5) micromol O(2) egg(-1) s(-1)). Tail movement throughout the perivitelline fluid began on day 3 and is likely to assist in moving oxygen around the embryo, complementing diffusive transport. The appearance of haemoglobin in the blood corresponded to a peak in oxygen consumption on day 4, where the highest mean rate of oxygen consumption was recorded (6.73+/-0.82x10(-5) micromol O(2) egg(-1) s(-1)). This could be a critical period in development whereby risk of mortality is increased through increased embryo requirements at developmental thresholds.

Investigating the Flow and Biomechanics of the Embryonic Zebrafish Heart

NASA Astrophysics Data System (ADS)

Johnson, Brennan; Garrity, Deborah; Dasi, Lakshmi

2010-11-01

Understanding flow and kinematic characteristics of the embryonic heart is a prerequisite to devise early intervention or detection methods in the context of congenital heart defects. In this study, the kinematics and fluid dynamics of the embryonic zebrafish heart were analyzed through the early stages of cardiac development (24-48 hours post-fertilization) in vivo using optical microscopy and high-speed video. Endocardial walls and individual blood cells were segmented from raw images and were tracked through the cardiac cycle. Particle tracking velocimetry analysis yielded quantitative blood cell velocity field, chamber volume, and flow rate information. It was seen that the pumping mechanism starts as a combined peristaltic and suction pump while the heart is in the tube configuration and transforms into a positive displacement pump after cardiac looping. Strong two-phase nature of the fluid is evident. This work provides us new understanding of the spatio-temporal characteristics of kinematics and blood cell velocity field inside the developing heart.

Phenotypic plasticity in the common snapping turtle (Chelydra serpentina): long-term physiological effects of chronic hypoxia during embryonic development.

PubMed

Wearing, Oliver H; Eme, John; Rhen, Turk; Crossley, Dane A

2016-01-15

Studies of embryonic and hatchling reptiles have revealed marked plasticity in morphology, metabolism, and cardiovascular function following chronic hypoxic incubation. However, the long-term effects of chronic hypoxia have not yet been investigated in these animals. The aim of this study was to determine growth and postprandial O2 consumption (V̇o2), heart rate (fH), and mean arterial pressure (Pm, in kPa) of common snapping turtles (Chelydra serpentina) that were incubated as embryos in chronic hypoxia (10% O2, H10) or normoxia (21% O2, N21). We hypothesized that hypoxic development would modify posthatching body mass, metabolic rate, and cardiovascular physiology in juvenile snapping turtles. Yearling H10 turtles were significantly smaller than yearling N21 turtles, both of which were raised posthatching in normoxic, common garden conditions. Measurement of postprandial cardiovascular parameters and O2 consumption were conducted in size-matched three-year-old H10 and N21 turtles. Both before and 12 h after feeding, H10 turtles had a significantly lower fH compared with N21 turtles. In addition, V̇o2 was significantly elevated in H10 animals compared with N21 animals 12 h after feeding, and peak postprandial V̇o2 occurred earlier in H10 animals. Pm of three-year-old turtles was not affected by feeding or hypoxic embryonic incubation. Our findings demonstrate that physiological impacts of developmental hypoxia on embryonic reptiles continue into juvenile life. Copyright © 2016 the American Physiological Society.

Melatonin regulates delayed embryonic development in the short-nosed fruit bat, Cynopterus sphinx.

PubMed

Banerjee, Arnab; Meenakumari, K J; Udin, S; Krishna, A

2009-12-01

The aim of the present study was to evaluate the seasonal variation in serum melatonin levels and their relationship to the changes in the serum progesterone level, ovarian steroidogenesis, and embryonic development during two successive pregnancies of Cynopterus sphinx. Circulating melatonin concentrations showed two peaks; one coincided with the period of low progesterone synthesis and delayed embryonic development, whereas the second peak coincided with regressing corpus luteum. This finding suggests that increased serum melatonin level during November-December may be responsible for delayed embryonic development by suppressing progesterone synthesis. The study showed increased melatonin receptors (MTNR1A and MTNR1B) in the corpus luteum and in the utero-embryonic unit during the period of delayed embryonic development. The in vitro study showed that a high dose of melatonin suppressed progesterone synthesis, whereas a lower dose of melatonin increased progesterone synthesis by the ovary. The effects of melatonin on ovarian steroidogenesis are mediated through changes in the expression of peripheral-type benzodiazepine receptor, P450 side chain cleavage enzyme, and LH receptor proteins. This study further showed a suppressive impact of melatonin on the progesterone receptor (PGR) in the utero-embryonic unit; this effect might contribute to delayed embryonic development in C. sphinx. The results of the present study thus suggest that a high circulating melatonin level has a dual contribution in retarding embryonic development in C. sphinx by impairing progesterone synthesis as well as by inhibiting progesterone action by reducing expression of PGR in the utero-embryonic unit.

Genetic Dissection of Maize Embryonic Callus Regenerative Capacity Using Multi-Locus Genome-Wide Association Studies

PubMed Central

Ma, Langlang; Liu, Min; Yan, Yuanyuan; Qing, Chunyan; Zhang, Xiaoling; Zhang, Yanling; Long, Yun; Wang, Lei; Pan, Lang; Zou, Chaoying; Li, Zhaoling; Wang, Yanli; Peng, Huanwei; Pan, Guangtang; Jiang, Zhou; Shen, Yaou

2018-01-01

The regenerative capacity of the embryonic callus, a complex quantitative trait, is one of the main limiting factors for maize transformation. This trait was decomposed into five traits, namely, green callus rate (GCR), callus differentiating rate (CDR), callus plantlet number (CPN), callus rooting rate (CRR), and callus browning rate (CBR). To dissect the genetic foundation of maize transformation, in this study multi-locus genome-wide association studies (GWAS) for the five traits were performed in a population of 144 inbred lines genotyped with 43,427 SNPs. Using the phenotypic values in three environments and best linear unbiased prediction (BLUP) values, as a result, a total of 127, 56, 160, and 130 significant quantitative trait nucleotides (QTNs) were identified by mrMLM, FASTmrEMMA, ISIS EM-BLASSO, and pLARmEB, respectively. Of these QTNs, 63 QTNs were commonly detected, including 15 across multiple environments and 58 across multiple methods. Allele distribution analysis showed that the proportion of superior alleles for 36 QTNs was <50% in 31 elite inbred lines. Meanwhile, these superior alleles had obviously additive effect on the regenerative capacity. This indicates that the regenerative capacity-related traits can be improved by proper integration of the superior alleles using marker-assisted selection. Moreover, a total of 40 candidate genes were found based on these common QTNs. Some annotated genes were previously reported to relate with auxin transport, cell fate, seed germination, or embryo development, especially, GRMZM2G108933 (WOX2) was found to promote maize transgenic embryonic callus regeneration. These identified candidate genes will contribute to a further understanding of the genetic foundation of maize embryonic callus regeneration. PMID:29755499

Effect of rearing temperatures during embryonic development on the phenotypic sex in zebrafish (Danio rerio).

PubMed

Abozaid, H; Wessels, S; Hörstgen-Schwark, G

2011-01-01

In zebrafish, Danio rerio, a polygenic pattern of sex determination or a female heterogamety with possible influences of environmental factors is assumed. The present study focuses on the effects of an elevated water temperature (35° C) during the embryonic development on sex determination in zebrafish. Eggs derived from 3 golden females were fertilized by the same mitotic gynogenetic male and exposed to a water temperature of 35° C, applied from 5 to 10 h post fertilization (hpf), from 5 to 24 hpf, and from 5 to 48 hpf, which correspond to the following developmental stages: gastrula, gastrula to segmentation, and gastrula to pharyngula stage, respectively. Hatching and survival rates decreased with increasing exposure to high water temperatures. Reductions in the hatching and survival rates were not responsible for differences in sex ratios. Accordingly, exposition of the fertilized eggs to a high temperature (35° C) leads to an increase of the male proportion from 22.0% in the controls to a balanced sex ratio (48.3, 47.5, and 52.6%) in the gastrula, segmentation, and pharyngula groups, respectively. These results prove the possibility to change the pathway of sexual determination during early embryonic stages in zebrafish by exposure to a high water temperature. Copyright © 2011 S. Karger AG, Basel.

Periconceptional maternal one-carbon biomarkers are associated with embryonic development according to the Carnegie stages.

PubMed

Parisi, F; Rousian, M; Koning, A H J; Willemsen, S P; Cetin, I; Steegers-Theunissen, R P M

2017-03-01

Is periconceptional maternal one-carbon (I-C) metabolism associated with embryonic morphological development in non-malformed ongoing pregnancies? Serum vitamin B12, red blood cell (RBC) folate and plasma total homocysteine (tHcy) are associated with embryonic development according to the Carnegie stages. Derangements in maternal I-C metabolism affect reproductive and pregnancy outcomes, as well as future health of the offspring. Between 2010 and 2014, women with singleton ongoing pregnancies were enrolled in a prospective periconceptional cohort study. A total of 234 pregnancies, including 138 spontaneous or IUI pregnancies with strict pregnancy dating and 96 pregnancies derived from IVF, ICSI or cryopreserved embryo transfer (IVF/ICSI pregnancies), underwent longitudinal transvaginal three-dimensional ultrasound (3D US) scans from 6+0 up to 10+2 weeks of gestation. Carnegie stages were defined using internal and external morphologic criteria in a virtual reality system. Maternal venous blood samples were collected at enrollment for serum vitamin B12, RBC folate and plasma tHcy assessment. Associations between biomarker concentrations and longitudinal Carnegie stages were investigated using linear mixed models. We performed a median of three 3D US scans per pregnancy (range 1-5) resulting in 600 good quality data sets for the Carnegie stage annotation (80.5%). Vitamin B12 was positively associated with embryonic development in the total study population (β = 0.001 (95% CI: 0.000; 0.002), P < 0.05) and in the subgroup of strictly dated spontaneous pregnancies (β = 0.002 (95% CI: 0.001; 0.003), P < 0.05). Low vitamin B12 concentrations (-2SD, 73.4 pmol/l) were associated with delayed embryonic development by 1.4 days (95% CI: 1.3-1.4) compared with high concentrations (+2SD, 563.1 pmol/l). RBC folate was positively associated with Carnegie stages only in IVF/ICSI pregnancies (β = 0.001 (95% CI: 0.0005; 0.0015), P < 0.05). In this group, low RBC folate concentrations (-2SD, 875.4 nmol/l) were associated with a 1.8-day delay (95% CI: 1.7-1.8) in development compared with high concentrations (+2SD, 2119.9 nmol/l). tHcy was negatively associated with embryonic development in the total study population (β = -0.08 (95% CI: -0.14; -0.02), P < 0.01), as well as in the IVF/ICSI subgroup (β = -0.08 (95% CI: -0.15; -0.01), P < 0.05). High tHcy concentrations (+2SD, 10.4 µmol/l) were associated with a delay of 1.6 days (95% CI: 1.5-1.7) in embryonic development compared with low concentrations (-2SD, 3.0 µmol/l). The study was performed in a tertiary care center, resulting in high rates of folic acid supplement use and comorbidity that may reduce the external validity of our findings. In periconceptional care, maternal I-C biomarkers should be taken into account as predictors of embryonic morphological development. Combining embryonic size measurements with morphological assessment could better define normal embryonic development. The work was funded by the Department of Obstetrics and Gynaecology, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. RPMST is CSO of the startup company Slimmere Zorg and CEO of eHealth Care Solutions. The authors declare no conflicts of interest. Not applicable. © 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

High embryonic recovery rates with in vivo and ex vivo techniques in the bitch.

PubMed

Luz, M R; de Holanda, C C; Pereira, J J; Freitas, P M C; Salgado, A E P; Giannotti, J Di Giorgio; de Oliveira, S B; Teixeira, N S; Guaitolini, C R de Freitas

2011-08-01

The embryonic collection techniques in dogs present a vast methodological variation and low recovery rates. The objectives were to compare and describe two techniques as to the recovery of canine embryos, on the 12th day after the first mating or artificial insemination. Embryos were recovered through uterine horn flushing in vivo, before performing the ovariohysterectomy (OHE) (Group 1; n = 9) or ex vivo, immediately after the OHE (Group 2; n = 9). In total, 43 and 47 embryonic structures were recovered in Groups 1 and 2, respectively. There was no significant difference (p > 0.05) between groups on recovery rates (72.8% and 81.0%, respectively). We inferred that both in vivo and ex vivo techniques allow a high rate of embryonic recovery; in the collection technique prior to the OHE, it is essential to carefully handle the reproductive system during the trans-surgical period and that the 12th day (D12) after the first mating/artificial insemination is an efficient option for the high recovery rate of morulae and blastocysts. © 2010 Blackwell Verlag GmbH.

Embryonic developmental patterns and energy expenditure are affected by incubation temperature in wood ducks (Aix sponsa).

PubMed

DuRant, S E; Hopkins, W A; Hepp, G R

2011-01-01

Recent research in birds has demonstrated that incubation temperature influences a suite of traits important for hatchling development and survival. We explored a possible mechanism for the effects on hatchling quality by determining whether incubation temperature influences embryonic energy expenditure of wood ducks (Aix sponsa). Because avian embryos are ectothermic, we hypothesized that eggs incubated at higher temperatures would have greater energy expenditure at any given day of incubation. However, because eggs incubated at lower temperatures take longer to hatch than embryos incubated at higher temperatures, we hypothesized that the former would expend more energy during incubation. We incubated eggs at three temperatures (35.0°, 35.9°, and 37.0°C) that fall within the range of temperatures of naturally incubated wood duck nests. We then measured the respiration of embryos every 3 d during incubation, immediately after ducks externally pipped, and immediately after hatching. As predicted, embryos incubated at the highest temperature had the highest metabolic rates on most days of incubation, and they exhibited faster rates of development. Yet, because of greater energy expended during the hatching process, embryos incubated at the lowest temperature expended 20%-37% more energy during incubation than did embryos incubated at the higher temperatures. Slower developmental rates and greater embryonic energy expenditure of embryos incubated at the lowest temperature could contribute to their poor physiological performance as ducklings compared with ducklings that hatch from eggs incubated at higher temperatures.

Embryonic lethality is not sufficient to explain hourglass-like conservation of vertebrate embryos.

PubMed

Uchida, Yui; Uesaka, Masahiro; Yamamoto, Takayoshi; Takeda, Hiroyuki; Irie, Naoki

2018-01-01

Understanding the general trends in developmental changes during animal evolution, which are often associated with morphological diversification, has long been a central issue in evolutionary developmental biology. Recent comparative transcriptomic studies revealed that gene expression profiles of mid-embryonic period tend to be more evolutionarily conserved than those in earlier or later periods. While the hourglass-like divergence of developmental processes has been demonstrated in a variety of animal groups such as vertebrates, arthropods, and nematodes, the exact mechanism leading to this mid-embryonic conservation remains to be clarified. One possibility is that the mid-embryonic period (pharyngula period in vertebrates) is highly prone to embryonic lethality, and the resulting negative selections lead to evolutionary conservation of this phase. Here, we tested this "mid-embryonic lethality hypothesis" by measuring the rate of lethal phenotypes of three different species of vertebrate embryos subjected to two kinds of perturbations: transient perturbations and genetic mutations. By subjecting zebrafish ( Danio rerio ), African clawed frog ( Xenopus laevis ), and chicken ( Gallus gallus ) embryos to transient perturbations, namely heat shock and inhibitor treatments during three developmental periods [early (represented by blastula and gastrula), pharyngula, and late], we found that the early stages showed the highest rate of lethal phenotypes in all three species. This result was corroborated by perturbation with genetic mutations. By tracking the survival rate of wild-type embryos and embryos with genetic mutations induced by UV irradiation in zebrafish and African clawed frogs, we found that the highest decrease in survival rate was at the early stages particularly around gastrulation in both these species. In opposition to the "mid-embryonic lethality hypothesis," our results consistently showed that the stage with the highest lethality was not around the conserved pharyngula period, but rather around the early period in all the vertebrate species tested. These results suggest that negative selection by embryonic lethality could not explain hourglass-like conservation of animal embryos. This highlights the potential contribution of alternative mechanisms such as the diversifying effect of positive selections against earlier and later stages, and developmental constraints which lead to conservation of mid-embryonic stages.

Blastocyst-like structures generated solely from stem cells.

PubMed

Rivron, Nicolas C; Frias-Aldeguer, Javier; Vrij, Erik J; Boisset, Jean-Charles; Korving, Jeroen; Vivié, Judith; Truckenmüller, Roman K; van Oudenaarden, Alexander; van Blitterswijk, Clemens A; Geijsen, Niels

2018-05-01

The blastocyst (the early mammalian embryo) forms all embryonic and extra-embryonic tissues, including the placenta. It consists of a spherical thin-walled layer, known as the trophectoderm, that surrounds a fluid-filled cavity sheltering the embryonic cells 1 . From mouse blastocysts, it is possible to derive both trophoblast 2 and embryonic stem-cell lines 3 , which are in vitro analogues of the trophectoderm and embryonic compartments, respectively. Here we report that trophoblast and embryonic stem cells cooperate in vitro to form structures that morphologically and transcriptionally resemble embryonic day 3.5 blastocysts, termed blastoids. Like blastocysts, blastoids form from inductive signals that originate from the inner embryonic cells and drive the development of the outer trophectoderm. The nature and function of these signals have been largely unexplored. Genetically and physically uncoupling the embryonic and trophectoderm compartments, along with single-cell transcriptomics, reveals the extensive inventory of embryonic inductions. We specifically show that the embryonic cells maintain trophoblast proliferation and self-renewal, while fine-tuning trophoblast epithelial morphogenesis in part via a BMP4/Nodal-KLF6 axis. Although blastoids do not support the development of bona fide embryos, we demonstrate that embryonic inductions are crucial to form a trophectoderm state that robustly implants and triggers decidualization in utero. Thus, at this stage, the nascent embryo fuels trophectoderm development and implantation.

[Influence of the DNA integrity of optimized sperm on the embryonic development and clinical outcomes of in vitro fertilization and embryo transfer].

PubMed

Jiang, Wei-jie; Jin, Fan; Zhou, Li-ming

2016-05-01

To investigate the influence of the DNA integrity of optimized sperm on the embryonic development and clinical outcomes of in vitro fertilization and embryo transfer (IVF-ET). This study included 605 cycles of conventional IVF-ET for pure oviductal infertility performed from January 1, 2013 to December 31, 2014. On the day of retrieval, we examined the DNA integrity of the sperm using the sperm chromatin dispersion method. According to the ROC curve and Youden index, we grouped the cycles based on the sperm DNA fragmentation index (DFI) threshold value for predicting implantation failure, early miscarriage, and fertilization failure, followed by analysis of the correlation between DFI and the outcomes of IVF-ET. According to the DFI threshold values obtained, the 605 cycles fell into four groups (DFI value < 5%, 5-10%, 10-15%, and ≥ 15%). Statistically significant differences were observed among the four groups in the rates of fertilization, cleavage, high-quality embryo, implantation, clinical pregnancy, early miscarriage, and live birth (P < 0.05), but not in the rates of multiple pregnancy, premature birth, and low birth weight (P > 0.05). DFI was found to be correlated negatively with the rates of fertilization (r = -0.32, P < 0.01), cleavage (r = -0.19, P < 0.01), high-quality embryo (r = -0.40, P < 0.01), clinical pregnancy (r = -0.20, P < 0.01), and live birth (r = -0.09 P = 0.04), positively with the rate of early miscarriage (r = 0.23, P < 0.01), but not with the rates of multiple pregnancy (r = -0.01, P = 0.83), premature birth (r = 0.04, P = 0.54), and low birth weight (r = 0.03, P = 0.62). The DNA integrity of optimized sperm influences fertilization, embryonic development, early miscarriage, and live birth of IVF-ET, but its correlation with premature birth and low birth weight has to be further studied.

The effect of temperature and light on embryogenesis and post-embryogenesis of the spider Eratigena atrica (Araneae, Agelenidae).

PubMed

Napiórkowska, Teresa; Kobak, Jarosław; Napiórkowski, Paweł; Templin, Julita

2018-02-01

Embryogenesis and post-embryogenesis of spiders depend on several environmental factors including light and temperature. This study was aimed at evaluating the impact of different thermal and lighting conditions on embryonic and early post-embryonic development of Eratigena atrica. Embryos, larvae, nymphs I and II were incubated at constant temperatures of 12, 22, 25 and 32°C under three different light regimes: light, dark, light/dark. Extreme temperatures (12 and 32°C) significantly increased mortality of embryos (to 100%) and nymphs II, whereas larvae and nymphs I suffered reduced survival only at the lowest temperature. Moreover, the lowest temperature reduced the development rate of all stages. The impact of light conditions was less pronounced and more variable: constant light reduced the survival of nymphs I at lower temperatures, but increased that of larvae. Moreover, light increased the time of embryonic development and duration of nymphal stages, particularly at lower temperatures (12-22°C). Thus, the most optimal locations for spiders seem to be dark (though except larval stage) and warm (25°C) sites, where their development is fastest and mortality lowest. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Berberine impairs embryonic development in vitro and in vivo through oxidative stress-mediated apoptotic processes.

PubMed

Huang, Chien-Hsun; Huang, Zi-Wei; Ho, Feng-Ming; Chan, Wen-Hsiung

2018-03-01

Berberine, an isoquinoline alkaloid isolated from several traditional Chinese herbal medicines, has been shown to suppress growth and induce apoptosis in some tumor cell lines. However, berberine has also been reported to attenuate H 2 O 2 -induced oxidative injury and apoptosis. The basis for these ambiguous effects of berberine-triggering or preventing apoptosis-has not been well characterized to date. In the current investigation, we examined whether berberine exerts cytotoxic effects on mouse embryos at the blastocyst stage and affects subsequent embryonic development in vitro and in vivo. Treatment of blastocysts with berberine (2.5-10 μM) induced a significant increase in apoptosis and a corresponding decrease in trophectoderm cell number. Moreover, the implantation success rate of blastocysts pretreated with berberine was lower than that of their control counterparts. Pretreatment with berberine was also associated with increased resorption of postimplantation embryos and decreased fetal weight. In an animal model, intravenous injection of berberine (2, 4, or 6 mg/kg body weight/d) for 4 days resulted in apoptosis of blastocyst cells and early embryonic developmental injury. Berberine-induced injury of mouse blastocysts appeared to be attributable to oxidative stress-triggered intrinsic apoptotic signaling processes that impaired preimplantation and postimplantation embryonic development. Taken together, our results clearly demonstrate that berberine induces apoptosis and retards early preimplantation and postimplantation development of mouse embryos, both in vitro and in vivo. © 2017 Wiley Periodicals, Inc.

Spatially resolved RNA-sequencing of the embryonic heart identifies a role for Wnt/β-catenin signaling in autonomic control of heart rate

PubMed Central

Burkhard, Silja Barbara

2018-01-01

Development of specialized cells and structures in the heart is regulated by spatially -restricted molecular pathways. Disruptions in these pathways can cause severe congenital cardiac malformations or functional defects. To better understand these pathways and how they regulate cardiac development we used tomo-seq, combining high-throughput RNA-sequencing with tissue-sectioning, to establish a genome-wide expression dataset with high spatial resolution for the developing zebrafish heart. Analysis of the dataset revealed over 1100 genes differentially expressed in sub-compartments. Pacemaker cells in the sinoatrial region induce heart contractions, but little is known about the mechanisms underlying their development. Using our transcriptome map, we identified spatially restricted Wnt/β-catenin signaling activity in pacemaker cells, which was controlled by Islet-1 activity. Moreover, Wnt/β-catenin signaling controls heart rate by regulating pacemaker cellular response to parasympathetic stimuli. Thus, this high-resolution transcriptome map incorporating all cell types in the embryonic heart can expose spatially restricted molecular pathways critical for specific cardiac functions. PMID:29400650

Thyroid hormone modulates offspring sex ratio in a turtle with temperature-dependent sex determination

PubMed Central

Li, Teng; Mu, Yi; McGlashan, Jessica K.; Georges, Arthur

2016-01-01

The adaptive significance of temperature-dependent sex determination (TSD) has attracted a great deal of research, but the underlying mechanisms by which temperature determines the sex of a developing embryo remain poorly understood. Here, we manipulated the level of a thyroid hormone (TH), triiodothyronine (T3), during embryonic development (by adding excess T3 to the eggs of the red-eared slider turtle Trachemys scripta, a reptile with TSD), to test two competing hypotheses on the proximate basis for TSD: the developmental rate hypothesis versus the hormone hypothesis. Exogenous TH accelerated embryonic heart rate (and hence metabolic rate), developmental rate, and rates of early post-hatching growth. More importantly, hyperthyroid conditions depressed expression of Cyp19a1 (the gene encoding for aromatase) and levels of oestradiol, and induced more male offspring. This result is contrary to the direction of sex-ratio shift predicted by the developmental rate hypothesis, but consistent with that predicted by the hormone hypothesis. Our results suggest an important role for THs in regulating sex steroid hormones, and therefore, in affecting gonadal sex differentiation in TSD reptiles. Our study has implications for the conservation of TSD reptiles in the context of global change because environmental contaminants may disrupt the activity of THs, and thereby affect offspring sex in TSD reptiles. PMID:27798296

Relationship between Dietary Fat Intake, Its Major Food Sources and Assisted Reproduction Parameters

PubMed Central

Kazemi, Ashraf; Ramezanzadeh, Fatemeh; Nasr-Esfahani, Mohammad Hosein

2014-01-01

Background High dietary fat consumption may alter oocyte development and embryonic development. This prospective study was conducted to determine the relation between dietary fat consumption level, its food sources and the assisted reproduction parameters. Methods A prospective study was conducted on 240 infertile women. In assisted reproduction treatment cycle, fat consumption and major food sources over the previous three months were identified. The number of retrieved oocytes, metaphase ΙΙ stage oocytes numbers, fertilization rate, embryo quality and clinical pregnancy rate were also determined. The data were analyzed using multiple regression, binary logistic regression, chi-square and t-test. The p-value of less than 0.05 was considered significant. Results Total fat intake adjusted for age, body mass index, physical activity and etiology of infertility was positively associated with the number of retrieved oocytes and inversely associated with the high embryo quality rate. An inverse association was observed between sausage and turkey ham intake and the number of retrieved oocytes. Also, oil intake level had an inverse association with good cleavage rate. Conclusion The results revealed that higher levels of fat consumption tend to increase the number of retrieved oocytes and were adversely related to embryonic development. Among food sources of fat, vegetable oil, sausage and turkey ham intake may adversely affect assisted reproduction parameters. PMID:25473630

Dimethadione embryotoxicity in the rat is neither correlated with maternal systemic drug concentrations nor embryonic tissue levels

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

Ozolinš, Terence R.S., E-mail: ozolinst@queensu.ca; Weston, Andrea D.; Perretta, Anthony

Pregnant rats treated with dimethadione (DMO), the N-demethylated metabolite of the anticonvulsant trimethadione, produce offspring having a 74% incidence of congenital heart defects (CHD); however, the incidence of CHD has high inter-litter variability (40–100%) that presents a challenge when studying the initiating events prior to the presentation of an abnormal phenotype. We hypothesized that the variability in CHD incidence was the result of differences in maternal systemic concentrations or embryonic tissue concentrations of DMO. To test this hypothesis, dams were administered 300 mg/kg DMO every 12 h from the evening of gestational day (GD) 8 until the morning of GDmore » 11 (six total doses). Maternal serum levels of DMO were assessed on GD 11, 12, 13, 14, 15, 18 and 21. Embryonic tissue concentrations of DMO were assessed on GD 11, 12, 13 and 14. In a separate cohort of GD 12 embryos, DMO concentrations and parameters of growth and development were assessed to determine if tissue levels of DMO were correlated with these endpoints. Embryos were exposed directly to different concentrations of DMO with whole embryo culture (WEC) and their growth and development assessed. Key findings were that neither maternal systemic concentrations nor tissue concentrations of DMO identified embryos that were sensitive or resistant to DMO in vivo. Direct exposure of embryos to DMO via WEC also failed to show correlations between embryonic concentrations of DMO with developmental outcomes in vitro. We conclude that neither maternal serum nor embryonic tissue concentrations of DMO predict embryonic outcome. - Highlights: • Dimethadione (DMO) induces septation defects (VSD) in rat offspring. • Despite high rate of VSD defects inter-litter variability is 40–100%. • Maternal and embryonic concentrations of DMO were assessed. • Neither serum nor tissue levels of DMO were correlated with embryotoxicity.« less

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.

High-Frequency Ultrasound for the Study of Early Mouse Embryonic Cardiovascular System.

PubMed

Greco, Adelaide; Coda, Anna Rita Daniela; Albanese, Sandra; Ragucci, Monica; Liuzzi, Raffaele; Auletta, Luigi; Gargiulo, Sara; Lamagna, Francesco; Salvatore, Marco; Mancini, Marcello

2015-12-01

An accurate diagnosis of congenital heart defects during fetal development is critical for interventional planning. Mice can be used to generate animal models with heart defects, and high-frequency ultrasound (HFUS) imaging enables in utero imaging of live mouse embryos. A wide range of physiological measurements is possible using Doppler-HFUS imaging; limitations of any single measurement warrant a multiparameter approach to characterize cardiovascular function. Doppler-HFUS was used to explore the embryonic (heart, aorta) and extraembryonic (umbilical blood flow) circulatory systems to create a database in normal mouse embryos between 9.5 and 16.5 days of gestation. Multivariate analyses were performed to explore correlations between gestational age and embryo echocardiographic parameters. Heart rate and peak velocity in the aorta were positively correlated with gestational time, whereas cardiac cycle length, isovolumetric relaxation time, myocardial performance index, and arterial deceleration time of the umbilical cord were negatively correlated with it. Doppler-HFUS facilitated detailed characterization of the embryonic mouse circulation and represents a useful tool for investigation of the early mouse embryonic cardiovascular system. © The Author(s) 2015.

The effects of an environmentally relevant 58-congener polychlorinated biphenyl (PCB) mixture on cardiac development in the chick embryo.

PubMed

Carro, Tiffany; Taneyhill, Lisa A; Ann Ottinger, Mary

2013-06-01

Chicken (Gallus domesticus) embryonic exposure in ovo to a 58-congener polychlorinated biphenyl (PCB) mixture resulted in teratogenic heart defects in chick embryos at critical heart developmental stages Hamburger-Hamilton (HH) stages 10, 16, and 20. The 58-congener mixture contained relative proportions of primary congeners measured in belted sandpiper (Megaceryle alcyon) and spotted sandpiper (Actitis macularia) eggs collected along the upper Hudson River, New York, USA, and chicken doses were well below observed environmental exposure levels. Embryos were injected with 0.08 µg PCBs/g egg weight and 0.50 µg PCBs/g egg weight (0.01 and 0.064 ng toxic equivalent/g, respectively) at embryonic day 0, prior to incubation. Mortality of exposed embryos was increased at all developmental stages, with a marked rise in cardiomyopathies at HH16 and HH20 (p < 0.05). Heart abnormalities occurred across all treatments, including abnormal elongation and expansion of the heart tube at HH10, improper looping and orientation, indentations in the emerging ventricular wall (HH16 and HH20), and irregularities in overall heart shape (HH10, HH16, and HH20). Histology was conducted on 2 cardiac proteins critical to embryonic heart development, ventricular myosin heavy chain and titin, to investigate potential mechanistic effects of PCBs on heart development, but no difference was observed in spatiotemporal expression. Similarly, cellular apoptosis in the developing heart was not affected by exposure to the PCB mixture. Conversely, cardiomyocyte proliferation rates dramatically declined (p < 0.01) at HH16 and HH20 as PCB exposure concentrations increased. Early embryonic cardiomyocyte proliferation contributes to proper formation of the morphology and overall thickness of the ventricular wall. Therefore, in ovo exposure to this 58-congener PCB mixture at critical stages adversely affects embryonic heart development. Copyright © 2013 SETAC.

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

The roles of ERAS during cell lineage specification of mouse early embryonic development.

PubMed

Zhao, Zhen-Ao; Yu, Yang; Ma, Huai-Xiao; Wang, Xiao-Xiao; Lu, Xukun; Zhai, Yanhua; Zhang, Xiaoxin; Wang, Haibin; Li, Lei

2015-08-01

Eras encodes a Ras-like GTPase protein that was originally identified as an embryonic stem cell-specific Ras. ERAS has been known to be required for the growth of embryonic stem cells and stimulates somatic cell reprogramming, suggesting its roles on mouse early embryonic development. We now report a dynamic expression pattern of Eras during mouse peri-implantation development: its expression increases at the blastocyst stage, and specifically decreases in E7.5 mesoderm. In accordance with its expression pattern, the increased expression of Eras promotes cell proliferation through controlling AKT activation and the commitment from ground to primed state through ERK activation in mouse embryonic stem cells; and the reduced expression of Eras facilitates primitive streak and mesoderm formation through AKT inhibition during gastrulation. The expression of Eras is finely regulated to match its roles in mouse early embryonic development during which Eras expression is negatively regulated by the β-catenin pathway. Thus, beyond its well-known role on cell proliferation, ERAS may also play important roles in cell lineage specification during mouse early embryonic development. © 2015 The Authors.

Embryonic exposure to benzo(a)pyrene inhibits reproductive capability in adult female zebrafish and correlation with DNA methylation.

PubMed

Gao, Dongxu; Lin, Jing; Ou, Kunlin; Chen, Ying; Li, Hongbin; Dai, Qinhua; Yu, Zhenni; Zuo, Zhenghong; Wang, Chonggang

2018-05-09

This study was conducted to investigate the effects of embryonic short-term exposure to benzo(a)pyrene (BaP), a model polycyclic aromatic hydrocarbon, on ovarian development and reproductive capability in adult female zebrafish. In 1-year-old fish after embryonic exposure to BaP for 96 h, the gonadosomatic indices and the percentage of mature oocytes were significantly decreased in the 0.5, 5 and 50 nmol/L treatments. The spawned egg number, the fertilization rate and the hatching success were significantly reduced, while the malformation rate of the F1 unexposed larvae were increased. The mRNA levels of follicle-stimulating hormone, luteinizing hormone, ovarian cytochrome P450 aromatase cyp19a1a and cyp19b, estrogen receptor esr1 and esr2, and hepatic vitellogenin vtg1 and vtg2 genes, were down-regulated in adult female zebrafish that were exposed to BaP during embryonic stage. Both 17β-estradiol and testosterone levels were reduced in the ovary of adult females. The methylation levels of the gonadotropin releasing hormone (GnRH) gene gnrh3 were significantly increased in the adult zebrafish brain, and those of the GnRH receptor gene gnrhr3 were elevated both in the larvae exposed to BaP and in the adult brain, which might cause the down-regulation of the mRNA levels of gnrh3 and gnrhr3. This epigenetic change caused by embryonic exposure to BaP might be a reason for physiological changes along the brain-pituitary-gonad axis. These results suggest that short-term exposure in early life should be included and evaluated in any risk assessment of pollutant exposure to the reproductive health of fish. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparison of normal and abnormal fertilization of in vitro-matured human oocyte according to insemination method.

PubMed

Park, Ju Hee; Jee, Byung Chul; Kim, Seok Hyun

2016-04-01

Our purpose was to compare the normal fertilization rate, multi-pronuclei (PN) formation rate, and embryonic development of in vitro-matured oocytes between conventional insemination and intracytoplasmic sperm injection (ICSI). A total of 213 stimulated in vitro fertilization (IVF) cycles were selected, in which at least one immature oocyte was obtained (from 2010 to 2014). Immature oocytes were assigned to germinal vesicle (GV)-stage or metaphase I (MI)-stage oocyte groups. Cycles with obligatory ICSI due to male-factor infertility were excluded. Cycles were divided into two groups according to fertilization method: there were 97 cycles with conventional insemination and 116 cycles with ICSI. After in vitro maturation of 324 GV-stage oocytes and 341 MI-stage oocytes, the fertilization rate, multi-PN formation rate, and embryonic development were compared according to the fertilization method. The normal fertilization rate was similar in the conventional insemination and the ICSI both in GV-derived and MI-derived oocytes. Both fertilization methods resulted in a similar multi-PN formation rate in GV-derived oocytes; however, in MI-derived oocytes, the multi-PN formation rate was zero with ICSI and this was significantly lower than that with conventional insemination (9.6%, P = 0.001). In non-male-factor infertility, ICSI should be considered when MI oocytes are matured. © 2016 Japan Society of Obstetrics and Gynecology.

Embryonic mammary signature subsets are activated in Brca1-/- and basal-like breast cancers

PubMed Central

2013-01-01

Introduction Cancer is often suggested to result from development gone awry. Links between normal embryonic development and cancer biology have been postulated, but no defined genetic basis has been established. We recently published the first transcriptomic analysis of embryonic mammary cell populations. Embryonic mammary epithelial cells are an immature progenitor cell population, lacking differentiation markers, which is reflected in their very distinct genetic profiles when compared with those of their postnatal descendents. Methods We defined an embryonic mammary epithelial signature that incorporates the most highly expressed genes from embryonic mammary epithelium when compared with the postnatal mammary epithelial cells. We looked for activation of the embryonic mammary epithelial signature in mouse mammary tumors that formed in mice in which Brca1 had been conditionally deleted from the mammary epithelium and in human breast cancers to determine whether any genetic links exist between embryonic mammary cells and breast cancers. Results Small subsets of the embryonic mammary epithelial signature were consistently activated in mouse Brca1-/- tumors and human basal-like breast cancers, which encoded predominantly transcriptional regulators, cell-cycle, and actin cytoskeleton components. Other embryonic gene subsets were found activated in non-basal-like tumor subtypes and repressed in basal-like tumors, including regulators of neuronal differentiation, transcription, and cell biosynthesis. Several embryonic genes showed significant upregulation in estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, and/or grade 3 breast cancers. Among them, the transcription factor, SOX11, a progenitor cell and lineage regulator of nonmammary cell types, is found highly expressed in some Brca1-/- mammary tumors. By using RNA interference to silence SOX11 expression in breast cancer cells, we found evidence that SOX11 regulates breast cancer cell proliferation and cell survival. Conclusions Specific subsets of embryonic mammary genes, rather than the entire embryonic development transcriptomic program, are activated in tumorigenesis. Genes involved in embryonic mammary development are consistently upregulated in some breast cancers and warrant further investigation, potentially in drug-discovery research endeavors. PMID:23506684

Effects of deer velvet extract from Formosan sika deer on the embryonic development and anti-oxidative enzymes mRNA expression in mouse embryos.

PubMed

Cheng, Shih-Lin; Lai, Yi-Ling; Lee, Ming-Che; Shen, Perng-Chih; Liu, Shyh-Shyan; Liu, Bing-Tsan

2014-07-03

The deer velvet or its extracts has been widely used in clinic. It has been used in promoting reproductive performances and treating of oxidation and aging process. The aim of this study is to investigate the effects of velvet extract from Formosan sika deer (Formosan sika deer; Cervus nippon taiouanus, FSD) velvet on mouse embryonic development and anti-oxidant ability in vitro. Mouse 4-cells embryos were divided into 16 groups for 72 h in vitro incubation. The embryonic development stages and morphology were evaluated every 12h in experimental period. The quantitative real time PCR was used to measure the CuZn-SOD, GPx and CAT mRNA expression of the blastocysts. The 4-cells embryos of hydrogen peroxide (HP) groups did not continue developing after oxidant stress challenged. The blastocyst developmental rate (90.0-90.4%, P>0.05) and normal morphological rate (84.4-85.1%, P>0.05) of the 1% and 2% DV extract groups were similar to those in the control group (90.7% and 88.8%, respectively). The embryos challenged by HP (5, 10 and 25 μM) and subsequently incubated in mHTF medium with 1% and 2% of deer velvet (DV) extracts were able to continue development; the blastocyst developmental rate of these groups were similar to that in the control group. The relative mRNA expression of the focused anti-oxidative enzymes in the mouse embryos did not significantly differ among the designed DV treatment groups (P>0.05). The FSD velvet extract in adequate concentration could promote anti-oxidative enzymes mRNA expression followed the challenge of hydrogen peroxide, relieve the mouse embryo under oxidative stress, and maintain the blastocyst developmental ability in vitro. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

A review of factors influencing the availability of dissolved oxygen to incubating salmonid embryos

NASA Astrophysics Data System (ADS)

Greig, S. M.; Sear, D. A.; Carling, P. A.

2007-01-01

Previous investigations into factors influencing incubation success of salmonid progeny have largely been limited to the development of empirical relationships between characteristics of the incubation environment and survival to emergence. It is suggested that adopting a process-based approach to assessing incubation success aids identification of the precise causes of embryonic mortalities, and provides a robust framework for developing and implementing managerial responses.Identifying oxygen availability within the incubation environment as a limiting factor, a comprehensive review of trends in embryonic respiration, and processes influencing the flux of oxygenated water through gravel riverbeds is provided. The availability of oxygen to incubating salmonid embryos is dependent on the exchange of oxygenated water with the riverbed, and the ability of the riverbed gravel medium to transport this water at a rate and concentration appropriate to support embryonic respiratory requirements. Embryonic respiratory trends indicate that oxygen consumption varies with stage of development, ambient water temperature and oxygen availability. The flux of oxygenated water through the incubation environment is controlled by a complex interaction of intragravel and extragravel processes and factors. The processes driving the exchange of channel water with gravel riverbeds include bed topography, bed permeability, and surface roughness effects. The flux of oxygenated water through riverbed gravels is controlled by gravel permeability, coupling of surface-subsurface flow and oxygen demands imposed by materials infiltrating riverbed gravels. Temporally and spatially variable inputs of groundwater can also influence the oxygen concentration of interstitial water. Copyright

Increased Regurgitant Flow Causes Endocardial Cushion Defects in an Avian Embryonic Model of Congenital Heart Disease

PubMed Central

Ford, Stephanie M; McPheeters, Matthew T; Wang, Yves T; Ma, Pei; Gu, Shi; Strainic, James; Snyder, Christopher; Rollins, Andrew M; Watanabe, Michiko; Jenkins, Michael W

2017-01-01

Background The relationship between changes in endocardial cushion and resultant congenital heart diseases (CHD) has yet to be established. It has been shown that increased regurgitant flow early in embryonic heart development leads to endocardial cushion defects, but it remains unclear how abnormal endocardial cushions during the looping stages might affect the fully septated heart. The goal of this study was to reproducibly alter blood flow in vivo and then quantify the resultant effects on morphology of endocardial cushions in the looping heart and on CHDs in the septated heart. Methods Optical pacing was applied to create regurgitant flow in embryonic hearts, and optical coherence tomography (OCT) was utilized to quantify regurgitation and morphology. Embryonic quail hearts were optically paced at 3 Hz (180bpm, well above intrinsic rate 60–110bpm) at stage 13 of development (3–4 wks human) for 5 min. Pacing fatigued the heart and led to at least 1 hr of increased regurgitant flow. Resultant morphological changes were quantified with OCT imaging at stage 19 (cardiac looping – 4–5 wks human) or stage 35 (4 chambered heart – 8 wks human). Results All paced embryos imaged at stage 19 displayed structural changes in cardiac cushions. The amount of regurgitant flow immediately after pacing was inversely correlated with cardiac cushion size 24-hrs post pacing (p-value < 0.01). The embryos with the most regurgitant flow and smallest cushions after pacing had a decreased survival rate at 8 days (p<0.05), indicating that those most severe endocardial cushion defects were lethal. Of the embryos that survived to stage 35, 17/18 exhibited CHDs including valve defects, ventricular septal defects, hypoplastic ventricles, and common AV canal. Conclusion The data illustrate a strong inverse relationship in which regurgitant flow precedes abnormal and smaller cardiac cushions, resulting in the development of CHDs. PMID:28211263

Maternal thyroid hormones enhance hatching success but decrease nestling body mass in the rock pigeon (Columba livia).

PubMed

Hsu, Bin-Yan; Dijkstra, Cor; Darras, Veerle M; de Vries, Bonnie; Groothuis, Ton G G

2017-01-01

Thyroid hormones (THs) - triiodothyronine (T3) and thyroxine (T4) - are essential for embryonic development in vertebrates. All vertebrate embryos are exposed to THs from maternal origin. As maternal TH levels are known to be essential to embryonic development, the natural variation of maternal THs probably represents a pathway of maternal effects that can modify offspring phenotype. However, potential fitness consequences of variation of maternal TH exposure within the normal physiological range and without confounding effects of the mother have never been experimentally investigated. We experimentally manipulated the levels of yolk T3 and T4 within the physiological range in a species in which the embryo develops outside the mother's body, the Rock Pigeon (Columba livia) eggs. Making use of the natural difference of yolk testosterone between the two eggs of pigeon clutches, we were also able to investigate the potential interaction between THs and testosterone. Elevated yolk TH levels enhanced embryonic development and hatching success, and reduced body mass but not tarsus length between day 14 and fledging. The yolk hormones increased plasma T4 concentrations in females but reduced it in males, in line with the effect on metabolic rate at hatching. Plasma concentrations of T3 and testosterone were not significantly affected. The effects of treatment did not differ between eggs with high or low testosterone levels. Our data indicate that natural variation in maternal yolk TH levels affects offspring phenotype and embryonic survival, potentially influencing maternal and chick fitness. Copyright © 2016 Elsevier Inc. All rights reserved.

Poor embryo development in post-ovulatory in vivo-aged mouse oocytes is associated with mitochondrial dysfunction, but mitochondrial transfer from somatic cells is not sufficient for rejuvenation.

PubMed

Igarashi, Hideki; Takahashi, Toshifumi; Abe, Hiroyuki; Nakano, Hiroshi; Nakajima, Osamu; Nagase, Satoru

2016-10-01

Does in vivo aging of mouse oocytes affect mitochondrial function? Mitochondrial function was impaired in post-ovulatory in vivo-aged mouse oocytes and microinjection of somatic cell mitochondria did not rescue poor fertilization and embryonic development rates. The mechanisms underlying the decline in oocyte quality associated with oocyte aging remain unknown, although studies have suggested that the decline is regulated by mitochondrial dysfunction. However, only a limited number of studies have provided direct evidence implicating mitochondrial dysfunction in oocyte quality during the aging of oocytes. We used post-ovulatory, in vivo-aged mouse oocytes as a model for studying low-quality oocytes in oocyte aging. Superovulated oocytes released from the oviduct at 14 h and 20-24 h post-hCG injection were designated as 'fresh' and 'aged' oocytes, respectively. Membrane potentials and oxygen consumption in single oocytes were evaluated as measures of mitochondrial function in fresh and aged oocytes. Mitochondrial transcriptional factor A (TFAM) expression levels were examined by western blotting, and colocalization of mitochondria and TFAM was analyzed by measuring immunofluorescence in fresh and aged oocytes. IVF and blastocyst formation rates were calculated after oocyte microinjection with mitochondria derived from liver cells. The average mitochondrial membrane potential in fresh oocytes was significantly higher than that in aged oocytes (P < 0.05). The average oxygen consumption rate in aged oocytes was significantly lower than that in fresh oocytes (P < 0.05). Although total TFAM expression was unchanged, its colocalization with mitochondria decreased in aged oocytes. IVF and blastocyst formation rates for mitochondrion-injected aged oocytes were not significantly different from those for buffer-injected aged oocytes. Not applicable. A limitation of this study is that we did not examine the effects of microinjecting mitochondria from other somatic cell types into aged oocytes on their fertilization and embryonic development rates. The results from the present study showed that poor embryonic development was associated with impairment of mitochondrial functions in in vivo-aged oocytes. However, the microinjection of mitochondria from liver cells did not improve the low fertilization and embryonic development rates of aged oocytes. It remains to be demonstrated whether oocyte quality can be rescued by the transfer of cytosolic factors or cellular organelles, such as the endoplasmic reticulum or mitochondria, from specific cell types. This study was supported by Grants-in-Aid for General Science Research to Toshifumi Takahashi (No. 25462550) and Hideki Igarashi (No. 26462474). The funding source played no role in study design in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the article for publication. The authors have no conflict of interest to disclose. © 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.

Early first trimester maternal 'high fish and olive oil and low meat' dietary pattern is associated with accelerated human embryonic development.

PubMed

Parisi, Francesca; Rousian, Melek; Steegers-Theunissen, Régine P M; Koning, Anton H J; Willemsen, Sten P; de Vries, Jeanne H M; Cetin, Irene; Steegers, Eric A P

2018-04-20

Maternal dietary patterns were associated with embryonic growth and congenital anomalies. We aim to evaluate associations between early first trimester maternal dietary patterns and embryonic morphological development among pregnancies with non-malformed outcome. A total of 228 strictly dated, singleton pregnancies without congenital malformations were enrolled in a periconceptional hospital-based cohort. Principal component analysis was performed to extract early first trimester maternal dietary patterns from food frequency questionnaires. Serial transvaginal three-dimensional ultrasound (3D US) scans were performed between 6 +0 and 10 +2 gestational weeks and internal and external morphological criteria were used to define Carnegie stages in a virtual reality system. Associations between dietary patterns and Carnegie stages were investigated using linear mixed models. A total of 726 3D US scans were included (median: three scans per pregnancy). The 'high fish and olive oil and low meat' dietary pattern was associated with accelerated embryonic development in the study population (β = 0.12 (95%CI: 0.00; 0.24), p < 0.05). Weak adherence to this dietary pattern delayed embryonic development by 2.1 days (95%CI: 1.6; 2.6) compared to strong adherence. The 'high vegetables, fruit and grain' dietary pattern accelerated embryonic development in the strictly dated spontaneous pregnancy subgroup without adjustment for energy intake. Early first trimester maternal dietary patterns impacts human embryonic morphological development among pregnancies without congenital malformations. The clinical meaning of delayed embryonic development needs further investigation.

Effects of heat stress on bovine preimplantation embryos produced in vitro

PubMed Central

SAKATANI, Miki

2017-01-01

Summer heat stress decreases the pregnancy rate in cattle and has been thought to be associated with the early embryonic death caused by the elevation of maternal body temperature. In vitro cultures have been widely used for the evaluation of effects of heat stress on oocytes, fertilization, preimplantation, and embryonic development. Susceptibility to heat stress is present in developmental stages from oocytes to cleavage-stage (before embryonic gene activation, EGA) embryos, leading to a consequent decrease in developmental competence. On the other hand, advanced-stage embryos such as morula or blastocysts have acquired thermotolerance. The mechanism for the developmental stage-dependent change in thermotolerance is considered to be the accumulation of antioxidants in embryos in response to heat-inducible production of reactive oxygen species. The supplementation of antioxidants to the culture media has been known to neutralize the detrimental effects of heat stress. Besides, EGA could be involved in acquisition of thermotolerance in later stages of embryos. Morulae or blastocysts can repair heat-induced unfolded proteins or prevent DNA damage occurring in processes such as apoptosis. Therefore, embryo transfer (ET) that can bypass the heat-sensitive stage could be a good solution to improve the pregnancy rate under heat stress. However, frozen-thawed ET could not improve the pregnancy rate as expected. Frozen-thawed blastocysts were more sensitive to heat stress and showed less proliferation upon heat exposure, compared to fresh blastocysts. Therefore, further research is required to improve the reduction in pregnancy rates due to summer heat stress. PMID:28496018

Effects of heat stress on bovine preimplantation embryos produced in vitro.

PubMed

Sakatani, Miki

2017-08-19

Summer heat stress decreases the pregnancy rate in cattle and has been thought to be associated with the early embryonic death caused by the elevation of maternal body temperature. In vitro cultures have been widely used for the evaluation of effects of heat stress on oocytes, fertilization, preimplantation, and embryonic development. Susceptibility to heat stress is present in developmental stages from oocytes to cleavage-stage (before embryonic gene activation, EGA) embryos, leading to a consequent decrease in developmental competence. On the other hand, advanced-stage embryos such as morula or blastocysts have acquired thermotolerance. The mechanism for the developmental stage-dependent change in thermotolerance is considered to be the accumulation of antioxidants in embryos in response to heat-inducible production of reactive oxygen species. The supplementation of antioxidants to the culture media has been known to neutralize the detrimental effects of heat stress. Besides, EGA could be involved in acquisition of thermotolerance in later stages of embryos. Morulae or blastocysts can repair heat-induced unfolded proteins or prevent DNA damage occurring in processes such as apoptosis. Therefore, embryo transfer (ET) that can bypass the heat-sensitive stage could be a good solution to improve the pregnancy rate under heat stress. However, frozen-thawed ET could not improve the pregnancy rate as expected. Frozen-thawed blastocysts were more sensitive to heat stress and showed less proliferation upon heat exposure, compared to fresh blastocysts. Therefore, further research is required to improve the reduction in pregnancy rates due to summer heat stress.

Arrested embryonic development: a review of strategies to delay hatching in egg-laying reptiles

PubMed Central

Rafferty, Anthony R.; Reina, Richard D.

2012-01-01

Arrested embryonic development involves the downregulation or cessation of active cell division and metabolic activity, and the capability of an animal to arrest embryonic development results in temporal plasticity of the duration of embryonic period. Arrested embryonic development is an important reproductive strategy for egg-laying animals that provide no parental care after oviposition. In this review, we discuss each type of embryonic developmental arrest used by oviparous reptiles. Environmental pressures that might have directed the evolution of arrest are addressed and we present previously undiscussed environmentally dependent physiological processes that may occur in the egg to bring about arrest. Areas for future research are proposed to clarify how ecology affects the phenotype of developing embryos. We hypothesize that oviparous reptilian mothers are capable of providing their embryos with a level of phenotypic adaptation to local environmental conditions by incorporating maternal factors into the internal environment of the egg that result in different levels of developmental sensitivity to environmental conditions after they are laid. PMID:22438503

The thyroid hormone receptor-associated protein TRAP220 is required at distinct embryonic stages in placental, cardiac, and hepatic development.

PubMed

Landles, Christian; Chalk, Sara; Steel, Jennifer H; Rosewell, Ian; Spencer-Dene, Bradley; Lalani, El-Nasir; Parker, Malcolm G

2003-12-01

Recent work indicates that thyroid hormone receptor-associated protein 220 (TRAP220), a subunit of the multiprotein TRAP coactivator complex, is essential for embryonic survival. We have generated TRAP220 conditional null mice that are hypomorphic and express the gene at reduced levels. In contrast to TRAP220 null mice, which die at embryonic d 11.5 (E11.5), hypomorphic mice survive until E13.5. The reduced expression in hypomorphs results in hepatic necrosis, defects in hematopoiesis, and hypoplasia of the ventricular myocardium, similar to that observed in TRAP220 null embryos at an earlier stage. The embryonic lethality of null embryos at E11.5 is due to placental insufficiency. Tetraploid aggregation assays partially rescues embryonic development until E13.5, when embryonic loss occurs due to hepatic necrosis coupled with poor myocardial development as observed in hypomorphs. These findings demonstrate that, for normal placental function, there is an absolute requirement for TRAP220 in extraembryonic tissues at E11.5, with an additional requirement in embryonic tissues for hepatic and cardiovascular development thereafter.

GLUT3 gene expression is critical for embryonic growth, brain development and survival.

PubMed

Carayannopoulos, Mary O; Xiong, Fuxia; Jensen, Penny; Rios-Galdamez, Yesenia; Huang, Haigen; Lin, Shuo; Devaskar, Sherin U

2014-04-01

Glucose is the primary energy source for eukaryotic cells and the predominant substrate for the brain. GLUT3 is essential for trans-placental glucose transport and highly expressed in the mammalian brain. To further elucidate the role of GLUT3 in embryonic development, we utilized the vertebrate whole animal model system of Danio rerio as a tractable system for defining the cellular and molecular mechanisms altered by impaired glucose transport and metabolism related to perturbed expression of GLUT3. The comparable orthologue of human GLUT3 was identified and the expression of this gene abrogated during early embryonic development. In a dose-dependent manner embryonic brain development was disrupted resulting in a phenotype of aberrant brain organogenesis, associated with embryonic growth restriction and increased cellular apoptosis. Rescue of the morphant phenotype was achieved by providing exogenous GLUT3 mRNA. We conclude that GLUT3 is critically important for brain organogenesis and embryonic growth. Disruption of GLUT3 is responsible for the phenotypic spectrum of embryonic growth restriction to demise and neural apoptosis with microcephaly. Copyright © 2014 Elsevier Inc. All rights reserved.

GLUT3 Gene Expression is Critical for Embryonic Growth, Brain Development and Survival

PubMed Central

Carayannopoulos, Mary O.; Xiong, Fuxia; Jensen, Penny; Rios-Galdamez, Yesenia; Huang, Haigen; Lin, Shuo; Devaskar, Sherin U.

2015-01-01

Glucose is the primary energy source for eukaryotic cells and the predominant substrate for the brain. GLUT3 is essential for trans-placental glucose transport and highly expressed in the mammalian brain. To further elucidate the role of GLUT3 in embryonic development, we utilized the vertebrate whole animal model system of Danio rerio as a tractable system for defining the cellular and molecular mechanisms altered by impaired glucose transport and metabolism related to perturbed expression of GLUT3. The comparable orthologue of human GLUT3 was identified and the expression of this gene abrogated during early embryonic development. In a dose-dependent manner embryonic brain development was disrupted resulting in a phenotype of aberrant brain organogenesis, associated with embryonic growth restriction and increased cellular apoptosis. Rescue of the morphant phenotype was achieved by providing exogenous GLUT3 mRNA. We conclude that GLUT3 is critically important for brain organogenesis and embryonic growth. Disruption of GLUT3 is responsible for the phenotypic spectrum of embryonic growth restriction to demise and neural apoptosis with microcephaly. PMID:24529979

Brief Embryonic Strychnine Exposure in Zebrafish Causes Long-Term Adult Behavioral Impairment with Indications of Embryonic Synaptic Changes

PubMed Central

Roy, Nicole M.; Arpie, Brianna; Lugo, Joseph; Linney, Elwood; Levin, Edward D.; Cerutti, Daniel

2015-01-01

Zebrafish provide a powerful model of the impacts of embryonic toxicant exposure on neural development that may result in long-term behavioral dysfunction. In this study, zebrafish embryos were treated with 1.5 mM strychnine for short embryonic time windows to induce transient changes in inhibitory neural signaling, and were subsequently raised in untreated water until adulthood. PCR analysis showed indications that strychnine exposure altered expression of some genes related to glycinergic, GABAergic and glutamatergic neuronal synapses during embryonic development. In adulthood, treated fish showed significant changes in swimming speed and tank diving behavior compared to controls. Taken together, these data show that a short embryonic exposure to a neurotoxicant can alter development of neural synapses and lead to changes in adult behavior. PMID:23022260

Brief embryonic strychnine exposure in zebrafish causes long-term adult behavioral impairment with indications of embryonic synaptic changes.

PubMed

Roy, Nicole M; Arpie, Brianna; Lugo, Joseph; Linney, Elwood; Levin, Edward D; Cerutti, Daniel

2012-01-01

Zebrafish provide a powerful model of the impacts of embryonic toxicant exposure on neural development that may result in long-term behavioral dysfunction. In this study, zebrafish embryos were treated with 1.5mM strychnine for short embryonic time windows to induce transient changes in inhibitory neural signaling, and were subsequently raised in untreated water until adulthood. PCR analysis showed indications that strychnine exposure altered expression of some genes related to glycinergic, GABAergic and glutamatergic neuronal synapses during embryonic development. In adulthood, treated fish showed significant changes in swimming speed and tank diving behavior compared to controls. Taken together, these data show that a short embryonic exposure to a neurotoxicant can alter development of neural synapses and lead to changes in adult behavior. Copyright © 2012 Elsevier Inc. All rights reserved.

High-throughput identification of small molecules that affect human embryonic vascular development

PubMed Central

Vazão, Helena; Rosa, Susana; Barata, Tânia; Costa, Ricardo; Pitrez, Patrícia R.; Honório, Inês; de Vries, Margreet R.; Papatsenko, Dimitri; Benedito, Rui; Saris, Daniel; Khademhosseini, Ali; Quax, Paul H. A.; Pereira, Carlos F.; Mercader, Nadia; Ferreira, Lino

2017-01-01

Birth defects, which are in part caused by exposure to environmental chemicals and pharmaceutical drugs, affect 1 in every 33 babies born in the United States each year. The current standard to screen drugs that affect embryonic development is based on prenatal animal testing; however, this approach yields low-throughput and limited mechanistic information regarding the biological pathways and potential adverse consequences in humans. To develop a screening platform for molecules that affect human embryonic development based on endothelial cells (ECs) derived from human pluripotent stem cells, we differentiated human pluripotent stem cells into embryonic ECs and induced their maturation under arterial flow conditions. These cells were then used to screen compounds that specifically affect embryonic vasculature. Using this platform, we have identified two compounds that have higher inhibitory effect in embryonic than postnatal ECs. One of them was fluphenazine (an antipsychotic), which inhibits calmodulin kinase II. The other compound was pyrrolopyrimidine (an antiinflammatory agent), which inhibits vascular endothelial growth factor receptor 2 (VEGFR2), decreases EC viability, induces an inflammatory response, and disrupts preformed vascular networks. The vascular effect of the pyrrolopyrimidine was further validated in prenatal vs. adult mouse ECs and in embryonic and adult zebrafish. We developed a platform based on human pluripotent stem cell-derived ECs for drug screening, which may open new avenues of research for the study and modulation of embryonic vasculature. PMID:28348206

High-throughput identification of small molecules that affect human embryonic vascular development.

PubMed

Vazão, Helena; Rosa, Susana; Barata, Tânia; Costa, Ricardo; Pitrez, Patrícia R; Honório, Inês; de Vries, Margreet R; Papatsenko, Dimitri; Benedito, Rui; Saris, Daniel; Khademhosseini, Ali; Quax, Paul H A; Pereira, Carlos F; Mercader, Nadia; Fernandes, Hugo; Ferreira, Lino

2017-04-11

Birth defects, which are in part caused by exposure to environmental chemicals and pharmaceutical drugs, affect 1 in every 33 babies born in the United States each year. The current standard to screen drugs that affect embryonic development is based on prenatal animal testing; however, this approach yields low-throughput and limited mechanistic information regarding the biological pathways and potential adverse consequences in humans. To develop a screening platform for molecules that affect human embryonic development based on endothelial cells (ECs) derived from human pluripotent stem cells, we differentiated human pluripotent stem cells into embryonic ECs and induced their maturation under arterial flow conditions. These cells were then used to screen compounds that specifically affect embryonic vasculature. Using this platform, we have identified two compounds that have higher inhibitory effect in embryonic than postnatal ECs. One of them was fluphenazine (an antipsychotic), which inhibits calmodulin kinase II. The other compound was pyrrolopyrimidine (an antiinflammatory agent), which inhibits vascular endothelial growth factor receptor 2 (VEGFR2), decreases EC viability, induces an inflammatory response, and disrupts preformed vascular networks. The vascular effect of the pyrrolopyrimidine was further validated in prenatal vs. adult mouse ECs and in embryonic and adult zebrafish. We developed a platform based on human pluripotent stem cell-derived ECs for drug screening, which may open new avenues of research for the study and modulation of embryonic vasculature.

Diploid, but not haploid, human embryonic stem cells can be derived from microsurgically repaired tripronuclear human zygotes

PubMed Central

Fan, Yong; Li, Rong; Huang, Jin; Yu, Yang; Qiao, Jie

2013-01-01

Human embryonic stem cells have shown tremendous potential in regenerative medicine, and the recent progress in haploid embryonic stem cells provides new insights for future applications of embryonic stem cells. Disruption of normal fertilized embryos remains controversial; thus, the development of a new source for human embryonic stem cells is important for their usefulness. Here, we investigated the feasibility of haploid and diploid embryo reconstruction and embryonic stem cell derivation using microsurgically repaired tripronuclear human zygotes. Diploid and haploid zygotes were successfully reconstructed, but a large proportion of them still had a tripolar spindle assembly. The reconstructed embryos developed to the blastocyst stage, although the loss of chromosomes was observed in these zygotes. Finally, triploid and diploid human embryonic stem cells were derived from tripronuclear and reconstructed zygotes (from which only one pronucleus was removed), but haploid human embryonic stem cells were not successfully derived from the reconstructed zygotes when two pronuclei were removed. Both triploid and diploid human embryonic stem cells showed the general characteristics of human embryonic stem cells. These results indicate that the lower embryo quality resulting from abnormal spindle assembly contributed to the failure of the haploid embryonic stem cell derivation. However, the successful derivation of diploid embryonic stem cells demonstrated that microsurgical tripronuclear zygotes are an alternative source of human embryonic stem cells. In the future, improving spindle assembly will facilitate the application of triploid zygotes to the field of haploid embryonic stem cells. PMID:23255130

Three-dimensional microCT imaging of murine embryonic development from immediate post-implantation to organogenesis: application for phenotyping analysis of early embryonic lethality in mutant animals.

PubMed

Ermakova, Olga; Orsini, Tiziana; Gambadoro, Alessia; Chiani, Francesco; Tocchini-Valentini, Glauco P

2018-04-01

In this work, we applied three-dimensional microCT imaging to study murine embryogenesis in the range from immediate post-implantation period (embryonic day 5.5) to mid-gestation (embryonic day 12.5) with the resolution up to 1.4 µm/voxel. Also, we introduce an imaging procedure for non-invasive volumetric estimation of an entire litter of embryos within the maternal uterine structures. This method allows for an accurate, detailed and systematic morphometric analysis of both embryonic and extra-embryonic components during embryogenesis. Three-dimensional imaging of unperturbed embryos was performed to visualize the egg cylinder, primitive streak, gastrulation and early organogenesis stages of murine development in the C57Bl6/N mouse reference strain. Further, we applied our microCT imaging protocol to determine the earliest point when embryonic development is arrested in a mouse line with knockout for tRNA splicing endonuclease subunit Tsen54 gene. Our analysis determined that the embryonic development in Tsen54 null embryos does not proceed beyond implantation. We demonstrated that application of microCT imaging to entire litter of non-perturbed embryos greatly facilitate studies to unravel gene function during early embryogenesis and to determine the precise point at which embryonic development is arrested in mutant animals. The described method is inexpensive, does not require lengthy embryos dissection and can be applicable for detailed analysis of mutant mice at laboratory scale as well as for high-throughput projects.

Single gene and gene interaction effects on fertilization and embryonic survival rates in cattle.

PubMed

Khatib, H; Huang, W; Wang, X; Tran, A H; Bindrim, A B; Schutzkus, V; Monson, R L; Yandell, B S

2009-05-01

Decrease in fertility and conception rates is a major cause of economic loss and cow culling in dairy herds. Conception rate is the product of fertilization rate and embryonic survival rate. Identification of genetic factors that cause the death of embryos is the first step in eliminating this problem from the population and thereby increasing reproductive efficiency. A candidate pathway approach was used to identify candidate genes affecting fertilization and embryo survival rates using an in vitro fertilization experimental system. A total of 7,413 in vitro fertilizations were performed using oocytes from 504 ovaries and semen samples from 10 different bulls. Fertilization rate was calculated as the number of cleaved embryos 48 h postfertilization out of the total number of oocytes exposed to sperm. Survival rate of embryos was calculated as the number of blastocysts on d 7 of development out of the number of total embryos cultured. All ovaries were genotyped for 8 genes in the POU1F1 signaling pathway. Single-gene analysis revealed significant associations of GHR, PRLR, STAT5A, and UTMP with survival rate and of POU1F1, GHR, STAT5A, and OPN with fertilization rate. To further characterize the contribution of the entire integrated POU1F1 pathway to fertilization and early embryonic survival, a model selection procedure was applied. Comparisons among the different models showed that interactions between adjacent genes in the pathway revealed a significant contribution to the variation in fertility traits compared with other models that analyzed only bull information or only genes without interactions. Moreover, some genes that were not significant in the single-gene analysis showed significant effects in the interaction analysis. Thus, we propose that single genes as well as an entire pathway can be used in selection programs to improve reproduction performance in dairy cattle.

An approach to clarify the effect mechanism of glyphosate on body malformations during embryonic development of zebrafish (Daino rerio).

PubMed

Sulukan, Ekrem; Köktürk, Mine; Ceylan, Hamid; Beydemir, Şükrü; Işik, Mesut; Atamanalp, Muhammed; Ceyhun, Saltuk Buğrahan

2017-08-01

In this study, it has been investigated that the effects of glyphosate, which is a herbicide within organophosphate and unselective widely used in agriculture on enzyme activity of carbonic anhydrase, production of reactive oxygen species, cell apoptosis and body morphology during the embryonic development of zebrafish. To this end, it has been treated embryo with 1, 5, 10 and 100 mg/L gyphosate at 96 h. The embryos treated with glyphosate from 4 hpf were evaluated by considering the survival rates, hatching rates, body malformations under the stereo microscope in 24, 48, 72 and 96th hours. In order to clarify the mechanism of the abnormalities ROS, enzyme activity of carbonic anhydrase and cellular death were detected end of the 96th hour. The data obtained in the present study have shown that glyphosate treatment inhibited CA activity, caused production of ROS especially branchial regions, triggered cellular apoptosis and caused several types of malformations including pericardial edema, yolk sac edema, spinal curvature and body malformation in a dose-dependent manner. As a conclusion, in light of present and previous studies, we can deduce that (1) the probable reason of ROS production was CA inhibition via decreasing of CO 2 extraction and developing respiratory acidosis (however, one needs to clarify), (2) abundance of ROS triggered cellular apoptosis and (3) as a result of cellular apoptosis malformations increased. These data will enable us to further understand potential toxic mechanism of glyphosate on embryonic development stage of zebrafish and may be useful for assessment in the toxicology studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Expression profile of IGF-I-calcineurin-NFATc3-dependent pathway genes in skeletal muscle during early development between duck breeds differing in growth rates.

PubMed

Shu, Jingting; Li, Huifang; Shan, Yanju; Xu, Wenjuan; Chen, Wenfeng; Song, Chi; Song, Weitao

2015-06-01

The insulin-like growth factor I (IGF-I)-calcineurin (CaN)-NFATc signaling pathways have been implicated in the regulation of myocyte hypertrophy and fiber-type specificity. In the present study, the expression of the CnAα, NFATc3, and IGF-I genes was quantified by RT-PCR for the first time in the breast muscle (BM) and leg muscle (LM) on days 13, 17, 21, 25, and 27 of embryonic development, as well as at 7 days posthatching (PH), in Gaoyou and Jinding ducks, which differ in their muscle growth rates. Consistent expression patterns of CnAα, NFATc3, and IGF-I were found in the same anatomical location at different development stages in both duck breeds, showing significant differences in an age-specific fashion. However, the three genes were differentially expressed in the two different anatomical locations (BM and LM). CnAα, NFATc3, and IGF-I messenger RNA (mRNA) could be detected as early as embryonic day 13 (ED13), and the highest level appeared at this stage in both BM and LM. Significant positive relationships were observed in the expression of the studied genes in the BM and LM of both duck breeds. Also, the expression of these three genes showed a positive relationship with the percentage of type IIb fibers and a negative relationship with the percentage of type I fibers and type IIa fibers. Our data indicate differential expression and coordinated developmental regulation of the selected genes involved in the IGF-I-calcineurin-NFATc3 pathway in duck skeletal muscle during embryonic and early PH growth and development; these data also indicate that this signaling pathway might play a role in the regulation of myofiber type transition.

GLUCOCORTICOID RECEPTOR EXPRESSION DURING THE DEVELOPMENT OF THE EMBRYONIC MOUSE SECONDARY PALATE

EPA Science Inventory

Glucocorticoids are important regulators of embryonic growth and development. hese effects are mediated through glucocorticoid receptors (GR) which bind to glucocorticoid response elements upstream of regulated genes. his study examines the expression of GR and GR mRNA in embryon...

Effects of incubation temperature on growth and performance of the veiled chameleon (Chamaeleo calyptratus).

PubMed

Andrews, Robin M

2008-10-01

I evaluated the effect of incubation temperature on phenotypes of the veiled chameleon, Chamaeleo calyptratus. I chose this species for study because its large clutch size (30-40 eggs or more) allows replication within clutches both within and among experimental treatments. The major research objectives were (1) to assess the effect of constant low, moderate, and high temperatures on embryonic development, (2) to determine whether the best incubation temperature for embryonic development also produced the "best" hatchlings, and (3) to determine how a change in incubation temperature during mid-development would affect phenotype. To meet these objectives, I established five experimental temperature regimes and determined egg survival and incubation length and measured body size and shape, selected body temperatures, and locomotory performance of lizards at regular intervals from hatching to 90 d, or just before sexual maturity. Incubation temperature affected the length of incubation, egg survival, and body mass, but did not affect sprint speed or selected body temperature although selected body temperature affected growth in mass independently of treatment and clutch. Incubation at moderate temperatures provided the best conditions for both embryonic and post-hatching development. The highest incubation temperatures were disruptive to development; eggs had high mortality, developmental rate was low, and hatchlings grew slowly. Changes in temperature during incubation increased the among-clutch variance in incubation length relative to that of constant temperature treatments. Copyright 2008 Wiley-Liss, Inc.

Luteal cell steroidogenesis in relation to delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx.

PubMed

Meenakumari, Karukayil J; Banerjee, Arnab; Krishna, Amitabh

2009-01-01

The primary aim of this study was to determine the possible cause of slow or delayed embryonic development in Cynopterus sphinx by investigating morphological and steroidogenic changes in the corpus luteum (CL) and circulating hormone concentrations during two pregnancies of a year. This species showed delayed post-implantational embryonic development during gastrulation of the first pregnancy. Morphological features of the CL showed normal luteinization during both pregnancies. The CL did not change significantly in luteal cell size during the delay period of the first pregnancy as compared with the second pregnancy. The circulating progesterone and 17beta-estradiol concentrations were significantly lower during the period of delayed embryonic development as compared with the same stage of embryonic development during the second pregnancy. We also showed a marked decline in the activity of 3beta-hydroxysteroid dehydrogenase, P450 side chain cleavage enzyme, and steroidogenic acute regulatory peptide in the CL during the delay period. This may cause low circulating progesterone and estradiol synthesis and consequently delay embryonic development. What causes the decrease in steroidogenic factors in the CL during the period of delayed development in C. sphinx is under investigation.

Jaw muscle development as evidence for embryonic repatterning in direct-developing frogs.

PubMed Central

Hanken, J; Klymkowsky, M W; Alley, K E; Jennings, D H

1997-01-01

The Puerto Rican direct-developing frog Eleutherodactylus coqui (Leptodactylidae) displays a novel mode of jaw muscle development for anuran amphibians. Unlike metamorphosing species, several larval-specific features never form in E. coqui; embryonic muscle primordia initially assume an abbreviated, mid-metamorphic configuration that is soon remodelled to form the adult morphology before hatching. Also lacking are both the distinct population of larval myofibres and the conspicuous, larval-to-adult myofibre turnover that are characteristic of muscle development in metamorphosing species. These modifications are part of a comprehensive alteration in embryonic cranial patterning that has accompanied life history evolution in this highly speciose lineage. Embryonic 'repatterning' in Eleutherodactylus may reflect underlying developmental mechanisms that mediate the integrated evolution of complex structures. Such mechanisms may also facilitate, in organisms with a primitively complex life cycle, the evolutionary dissociation of embryonic, larval, and adult features. PMID:9332017

Effects of Vitrification on Outcomes of In Vivo-Mature, In Vitro-Mature and Immature Human Oocytes.

PubMed

Song, Wen-Yan; Peng, Zhao-Feng; Chen, Xue-Mei; Jin, Hai-Xia; Yao, Gui-Dong; Shi, Sen-Lin; Yang, Hong-Yi; Zhang, Xiang-Yang; Sun, Ying-Pu

2016-01-01

To observe the effects of vitrification on spindle, zona pellucida, embryonic aneuploidy and DNA injury in in vivo-maruted, in vitro-mature and immature human oocytes. Between January 2009 and February 2015, 223 immature oocytes from 450 infertile patients, and 31 in vivo-mature oocytes from 3 infertile couples were collected. Of the 223 immature oocytes, 113 were used for in vitro culture before vitrification. Some oocytes were randomly divided into in vivo-mature group (group A, n = 15), in vitro-mature group (group B, n = 88) and immature group (group C, n = 85), and then the oocytes with spindle in these three groups after freezing-thawing were selected to use for Polscope imaging, embryonic aneuploidy screening and embryo development evaluation. Other oocytes were randomly divided into group A (n = 16), group B (n = 25) and group C (n = 25) for detecting DNA injury. After thawing, spindle occurrence rate, spindle Retardance value, and cleavage rate were significantly higher in groups A and B than in group C (all P < 0.05), but there were no statistical differences in fertility rate, high-quality embryo rate, blastulation rate and aneuploidy rate amongst the three groups (all P > 0.05). Zona pellucida density (ZPD) was significantly lower in group A than in groups B and C both before and after vitrification (all P < 0.05). ZPD was significantly higher after thawing than before vitrification (all P < 0.05), but zona pellucida thickness (ZPT) was not significantly changed in all the three groups (all P > 0.05). Rate of comet cells was significantly lower in group A than in groups B and C (all P < 0.01). Comet tail was significantly longer in group C than in groups B and A (all P < 0.05). In vivo- and in vitro-mature human oocytes are more suitable to vitrification than immature human oocytes. Spindle Retardance value has more predictive value for embryonic development potential than ZPD and ZPT. © 2016 The Author(s) Published by S. Karger AG, Basel.

Embryonic death is linked to maternal identity in the leatherback turtle (Dermochelys coriacea).

PubMed

Rafferty, Anthony R; Santidrián Tomillo, Pilar; Spotila, James R; Paladino, Frank V; Reina, Richard D

2011-01-01

Leatherback turtles have an average global hatching success rate of ~50%, lower than other marine turtle species. Embryonic death has been linked to environmental factors such as precipitation and temperature, although, there is still a lot of variability that remains to be explained. We examined how nesting season, the time of nesting each season, the relative position of each clutch laid by each female each season, maternal identity and associated factors such as reproductive experience of the female (new nester versus remigrant) and period of egg retention between clutches (interclutch interval) affected hatching success and stage of embryonic death in failed eggs of leatherback turtles nesting at Playa Grande, Costa Rica. Data were collected during five nesting seasons from 2004/05 to 2008/09. Mean hatching success was 50.4%. Nesting season significantly influenced hatching success in addition to early and late stage embryonic death. Neither clutch position nor nesting time during the season had a significant affect on hatching success or the stage of embryonic death. Some leatherback females consistently produced nests with higher hatching success rates than others. Remigrant females arrived earlier to nest, produced more clutches and had higher rates of hatching success than new nesters. Reproductive experience did not affect stage of death or the duration of the interclutch interval. The length of interclutch interval had a significant affect on the proportion of eggs that failed in each clutch and the developmental stage they died at. Intrinsic factors such as maternal identity are playing a role in affecting embryonic death in the leatherback turtle.

Adrenal hormones interact with sympathetic innervation to modulate growth of embryonic heart in oculo.

PubMed

Tucker, D C; Torres, A

1992-02-01

To allow experimental manipulation of adrenal hormone and autonomic influences on developing myocardium without alteration of hemodynamic load, embryonic rat heart was cultured in the anterior eye chamber of an adult rat. Sympathetic innervation of embryonic day 12 heart grafts was manipulated by surgical sympathectomy of one eye chamber in each host rat. Adrenal hormone exposure was manipulated by host adrenal medullectomy (MEDX) in experiment 1 and by host adrenalectomy (ADX) in experiment 2. In experiment 1, whole heart grafts were larger in MEDX than in sham-operated hosts by 8 wk in oculo (6.14 +/- 0.71 vs. 5.09 +/- 0.69 mm2 with innervation intact and 7.97 +/- 2.07 vs. 3.09 +/- 0.63 mm2 with sympathetic innervation prevented). In experiment 2, host ADX increased growth of embryonic day 12 ventricles grafted into sympathectomized eye chambers (0.69 +/- 0.10 vs. 0.44 +/- 0.04 mm2) but did not affect growth of grafts in intact eye chambers (0.85 +/- 0.09 vs. 1.05 +/- 0.15 mm2). Corticosterone replacement (4 mg/day) entirely reversed the effect of host ADX on graft growth (superior cervical ganglionectomy, 0.47 +/- 0.03 mm2; intact eye chambers, 0.90 +/- 0.91 mm2). Beating rate of grafts was not affected by adrenal hormone manipulations. These experiments indicate that the compromised growth of embryonic heart grafts placed in sympathectomized eye chambers requires exposure to adult levels of glucocorticoids during the early days after grafting. These results suggest that interactions between neural and hormonal stimulation influence cardiac growth in the in oculo culture system and during normal development.

Does dietary fat intake influence oocyte competence and embryo quality by inducing oxidative stress in follicular fluid?

PubMed

Kazemi, Ashraf; Ramezanzadeh, Fatemeh; Nasr-Esfahani, Mohammad Hosein; Saboor Yaraghi, Ali Akbar; Ahmadi, Mehdi

2013-12-01

Fat-rich diet may alter oocyte development and maturation and embryonic development by inducing oxidative stress (OS) in follicular environment. To investigate the relationship between fat intake and oxidative stress with oocyte competence and embryo quality. In observational study follicular fluid was collected from 236 women undergoing assisted reproduction program. Malon-di-aldehyde (MDA) levels and total antioxidant capacity (TAC) levels of follicular fluid were assessed as oxidative stress biomarkers. In assisted reproduction treatment cycle fat consumption and its component were assessed. A percentage of metaphase ΙΙ stage oocytes, fertilization rate were considered as markers of oocyte competence and non-fragmented embryo rate, mean of blastomer and good cleavage (embryos with more than 5 cells on 3 days post insemination) rate were considered as markers of embryo quality. The MDA level in follicular fluid was positively related to polyunsaturated fatty acids intake level (p=0.02) and negatively associated with good cleavage rate (p=0.045). Also good cleavage rate (p=0.005) and mean of blastomer (p=0.006) was negatively associated with polyunsaturated fatty acids intake levels. The percentage of metaphase ΙΙ stage oocyte was positively related to the TAC levels in follicular fluid (p=0.046). The relationship between the OS biomarkers in FF and the fertilization rate was not significant. These findings revealed that fat rich diet may induce the OS in oocyte environment and negatively influence embryonic development. This effect can partially be accounted by polyunsaturated fatty acids uptake while oocyte maturation is related to TAC and oocytes with low total antioxidant capacity have lower chance for fertilization and further development.

Incubation times of dinosaur eggs via embryonic metabolism

NASA Astrophysics Data System (ADS)

Lee, Scott A.

2016-08-01

The incubation times for the eggs of 21 dinosaurs are determined from an estimate of their embyronic metabolic rate and the mass of the hatchlings via a mass growth model based on conservation of energy. Embryos in extant birds and crocodiles are studied in order to determine the best model for embryonic metabolism and growth. These results are used to develop a theoretical model that predicts the incubation times of an egg. This model is applied to dinosaur eggs and provides a unique window into dinosaur reproduction. The dinosaurs studied come from both Saurischia and Ornithischia. The incubation times vary from about 28 days for Archaeopteryx lithographica to about 76 days for Alamosaurus sanjuanensis.

Incubation times of dinosaur eggs via embryonic metabolism.

PubMed

Lee, Scott A

2016-08-01

The incubation times for the eggs of 21 dinosaurs are determined from an estimate of their embyronic metabolic rate and the mass of the hatchlings via a mass growth model based on conservation of energy. Embryos in extant birds and crocodiles are studied in order to determine the best model for embryonic metabolism and growth. These results are used to develop a theoretical model that predicts the incubation times of an egg. This model is applied to dinosaur eggs and provides a unique window into dinosaur reproduction. The dinosaurs studied come from both Saurischia and Ornithischia. The incubation times vary from about 28 days for Archaeopteryx lithographica to about 76 days for Alamosaurus sanjuanensis.

[Oxygen consumption rate of Sepia pharaonis embryos.

PubMed

Wang, Peng Shuai; Jiang, Xia Min; Ruan, Peng; Peng, Rui Bing; Jiang, Mao Wang; Han, Qing Xi

2016-07-01

This research was conducted to unravel the variation of oxygen consumption rate during different developmental stages and the effects of different ecological factors on embryonic oxygen consumption rate of Sepia pharaonis. The oxygen consumption rates were measured at twelve deve-lopmental stages by the sealed volumetric flasks, and four embryonic developmental periods (oosperm, gastrula, the formation of organization, endoskeleton) were selected under various ecological conditions, such as salinity (21, 24, 27, 30, 33), water temperature (18, 21, 24, 27, 30 ℃) and pH (7.0, 7.5, 8.0, 8.5, 9.0). The results showed that the oxygen consumption rate rose along with the developmental progress, and distinctly differed from each other. The oxygen consumption rate was 0.082 mg·(100 eggs) -1 ·h -1 during oosperm period, and rose to 0.279 mg·(100 eggs) -1 ·h -1 during gastrula period, which was significantly higher than that of blastula period. Finally, the oxygen consumption rate rose to 1.367 mg·(100 eggs) -1 ·h -1 during hatching period. The salinity showed a significant effect on oxygen consumption rate during the formation of organization and endoskeleton formation stage (P<0.05), but no significant effect during oosperm and gastrula periods (P>0.05). The oxygen consumption rates of four studied embryonic stages all rose and then declined along with the increase of salinity, and reached the highest values [0.082, 0.200, 0.768 and 1.301 mg·(100 eggs) -1 ·h -1 , respectively] at salinity 30. The water temperature had a significant effect on the embryo oxygen consumption rates of gastrula, and the formation of organization and endoskeleton formation stage (P<0.05), with the exception of oosperm (P>0.05). The oxygen consumption rates of four studied embryonic stages all rose and then declined along with the increase of temperature, and reached the highest values at 27 ℃ [0.082, 0.286, 0.806 and 1.338 mg·(100 eggs) -1 ·h -1 , respectively]. The pH had no significant effect on the oxygen consumption rates of four embryonic stages (P>0.05). The oxygen consumption rates of four studied embryonic stages all rose and then declined along with the increase of pH. The oxygen consumption rates of gastrula, the formation of organization, endoskeleton reached the according highest values [0.281, 0.799 and 1.130 mg·(100 eggs) -1 ·h -1 ] at pH 8.5, but that during oosperm period occurred at pH 8.0 [0.116 mg·(100 eggs) -1 ·h -1 ].

Effect of breeding method and season on pregnancy rate and embryonic and fetal losses in lactating Nili-Ravi buffaloes.

PubMed

Qayyum, Arslan; Arshad, Usman; Yousuf, Muhammad Rizwan; Ahmad, Nasim

2018-03-01

The aim of this study was to determine the effect of breeding method and season on pregnancy rate and cumulative embryonic and fetal losses in Nili-Ravi buffalo. Estrus detection was performed twice a day by teaser buffalo bull for 1 hour each. A 2 × 2 factorial design was used to address the breeding method and season. Buffaloes (n = 130) exhibiting estrus were randomly assigned to be bred either in peak breeding season (PBS; n = 80) or low breeding season (LBS; n = 50). Within each season, buffaloes were divided to receive either natural service (NS; n = 65) or artificial insemination (AI; n = 65). NS buffaloes, in estrus, were allowed to remain with the bull until mating. AI was achieved, using frozen thawed semen of bull of known fertility. PBS comprised of September to December and LBS were from May to July. Serial ultrasonography was performed on days 30, 45, 60, and 90 after breeding (day 0) to monitor pregnancy rate and embryonic and fetal losses. The pregnancy rate on day 30 after breeding was higher in NS as compared to AI group (63 vs. 43%; P < 0.05) during PBS while it did not differ (48 vs. 32%; P > 0.05) in LBS. The cumulative embryonic and fetal losses between days 31 and 90 were significantly lower in PBS than LBS (33 vs. 60%; P < 0.05), ignoring breeding method. Pregnancy rates were better with NS in PBS, and cumulative embryonic fetal losses were higher in LBS in Nili-Ravi buffalo.

Rate of Dehydration and Cumulative Desiccation Stress Interacted to Modulate Desiccation Tolerance of Recalcitrant Cocoa and Ginkgo Embryonic Tissues1

PubMed Central

Liang, Yongheng; Sun, Wendell Q.

2002-01-01

Rate of dehydration greatly affects desiccation tolerance of recalcitrant seeds. This effect is presumably related to two different stress vectors: direct mechanical or physical stress because of the loss of water and physicochemical damage of tissues as a result of metabolic alterations during drying. The present study proposed a new theoretic approach to represent these two types of stresses and investigated how seed tissues responded differently to two stress vectors, using the models of isolated cocoa (Theobroma cacao) and ginkgo (Ginkgo biloba) embryonic tissues dehydrated under various drying conditions. This approach used the differential change in axis water potential (ΔΨ/Δt) to quantify rate of dehydration and the intensity of direct physical stress experienced by embryonic tissues during desiccation. Physicochemical effect of drying was expressed by cumulative desiccation stress [∫\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\pagestyle{empty} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{_{o}^{t}}}\\end{equation*}\\end{document}f(ψ,t)], a function of both the rate and time of dehydration. Rapid dehydration increased the sensitivity of embryonic tissues to desiccation as indicated by high critical water contents, below which desiccation damage occurred. Cumulative desiccation stress increased sharply under slow drying conditions, which was also detrimental to embryonic tissues. This quantitative analysis of the stress-time-response relationship helps to understand the physiological basis for the existence of an optimal dehydration rate, with which maximum desiccation tolerance could be achieved. The established numerical analysis model will prove valuable for the design of experiments that aim to elucidate biochemical and physiological mechanisms of desiccation tolerance. PMID:11950981

Evaluation of 309 environmental chemicals using a mouse embryonic stem cell adherent cell differentiation and cytotoxicity assay

EPA Science Inventory

The vast landscape of environmental chemicals has motivated the need for alternative methods to traditional whole-animal bioassays in toxicity testing. Embryonic stem (ES) cells provide an in vitro model of embryonic development and an alternative method for assessing development...

Adverse Outcome Pathway for Embryonic Vascular Disruption and Alternative Methods to Identify Chemical Vascular Disruptors During Development

EPA Science Inventory

Chemically induced vascular toxicity during embryonic development can result in a wide range of adverse prenatal outcomes. We used information from genetic mouse models linked to phenotypic outcomes and a vascular toxicity knowledge base to construct an embryonic vascular disrupt...

DNA damage in bovine sperm does not block fertilization and early embryonic development but induces apoptosis after the first cleavages.

PubMed

Fatehi, A N; Bevers, M M; Schoevers, E; Roelen, B A J; Colenbrander, B; Gadella, B M

2006-01-01

The main goal of this study was to investigate whether and at what level damage of paternal DNA influences fertilization of oocytes and early embryonic development. We hypothesized that posttesticular sperm DNA damage will only marginally affect sperm physiology due to the lack of gene expression, but that it will affect embryo development at the stage that embryo genome (including the paternal damaged DNA) expression is initiated. To test this, we artificially induced sperm DNA damage by irradiation with x- or gamma rays (doses of 0-300 Gy). Remarkably, sperm cells survived the irradiation quite well and, when compared with nonirradiated cells, sperm motility and integrity of plasma membrane, acrosome, and mitochondria were not altered by this irradiation treatment. In contrast, a highly significant logarithmic relation between irradiation dose and induced DNA damage to sperm cells was found by both terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) and the acridin orange assay. Despite the DNA damage, irradiated sperm cells did not show any sign of apoptosis (nuclear fragmentation, depolarization of inner mitochondrial membranes, or phospholipid scrambling) and were normally capable of fertilizing oocytes, as there was no reduction in cleavage rates when compared with nonirradiated sperm samples up to irradiation doses of less than 10 Gy. Further embryonic development was completely blocked as the blastocyst rates at days 7 and 9 dropped from 28% (nonirradiated sperm) to less than 3% by greater than 2.5-Gy-irradiated sperm. This block in embryonic development was accompanied with the initiation of apoptosis after the second or third cleavage. Specific signs of apoptosis, such as nuclear fragmentation and aberrations in spindle formation, were observed in all embryos resulting from in vitro fertilization with irradiated sperm (irradiation doses >1.25 Gy). The results show that sperm DNA damage does not impair fertilization of the oocyte or completion of the first 2-3 cleavages, but blocks blastocyst formation by inducing apoptosis. Embryos produced by assisted reproductive techniques (ART) could have incorporated aberrant paternal DNA (frequently detected in sperm of sub/infertile males). Analogously, in the present work, we discuss the possibility of following embryo development of oocytes fertilized by ART through the blastocyst stage before embryo transfer into the uterus in order to reduce risks of reproductive failure.

Growth and differentiation of mammalian embryonic tissues exposed to hypergravity in vivo and in vitro

NASA Technical Reports Server (NTRS)

Duke, P. J.

1984-01-01

In about 10 years or so, men and women from Earth will be long-term inhabitants of a space station aboard which plants and animals will be growing and developing in gravities other than that of Earth. The effect of gravitational changes on development was examined. It is indicated that differentiation is speeded up under excess G and slowed in low or null G. The effects of exposure to excess gravity on fusion of the embryonic mouse secondary palate were studied. During fusion, the palatal shelves first adhere by means of glycoproteins appearing along the medial epithelial edge (MEE). The contacting epithelia then reorganize and undergo programmed cell death, allowing the underlying mesenchymes to come in contact. The process of cell death occurs in vitro at about the same rate that it occurs in vivo.

Subcutaneous transplantation of embryonic pancreas for correction of type 1 diabetes

PubMed Central

Gunawardana, Subhadra C.; Benninger, Richard K. P.; Piston, David W.

2009-01-01

Islet transplantation is a promising therapeutic approach for type 1 diabetes. However, current success rates are low due to progressive graft failure in the long term and inability to monitor graft development in vivo. Other limitations include the necessity of initial invasive surgery and continued immunosuppressive therapy. We report an alternative transplantation strategy with the potential to overcome these problems. This technique involves transplantation of embryonic pancreatic tissue into recipients’ subcutaneous space, eliminating the need for invasive surgery and associated risks. Current results in mouse models of type 1 diabetes show that embryonic pancreatic transplants in the subcutaneous space can normalize blood glucose homeostasis and achieve extensive endocrine differentiation and vascularization. Furthermore, modern imaging techniques such as two-photon excitation microscopy (TPEM) can be employed to monitor transplants through the intact skin in a completely noninvasive manner. Thus, this strategy is a convenient alternative to islet transplantation in diabetic mice and has the potential to be translated to human clinical applications with appropriate modifications. PMID:19066321

Can the eastern red-backed salamander (Plethodon cinereus) persist in an acidified landscape?

Treesearch

Cheryl A. Bondi; Colin M. Beier; Peter K. Ducey; Gregory B. Lawrence; Scott Bailey

2016-01-01

Hardwood forests of eastern North America have experienced decades of acidic deposition, leading to soil acidification where base cation supply was insufficient to neutralize acid inputs. Negative impacts of soil acidity on amphibians include disrupted embryonic development, lower growth rates, and habitat loss. However, some amphibians exhibit intraspecific variation...

Plate Tectonism on Early Mars: Diverse Geological and Geophysical Evidence

NASA Technical Reports Server (NTRS)

Dohm, J. M.; Maruyama, S.; Baker, V. R.; Anderson, R. C.; Ferris, Justin C.; Hare, Trent M.

2002-01-01

Mars has been modified by endogenic and exogenic processes similar in many ways to Earth. However, evidence of Mars embryonic development is preserved because of low erosion rates and stagnant lid convective conditions since the Late Noachian. Early plate tectonism can explain such evidence. Additional information is contained in the original extended abstract.

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.

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.

Early pregnancy factor (EPF) as a marker for detecting subclinical embryonic loss in clomiphene citrate-treated women.

PubMed

Shahani, S K; Moniz, C L; Gokral, J S; Meherji, P K

1995-05-01

A discrepancy exists between the apparently normal ovulation and the pregnancy rates in women treated with clomiphene citrate (CC). Our previous studies have indicated that immuno-suppressive "early pregnancy factor" (EPF) is a novel marker to detect subclinical embryonic loss in infertile women. In the present study EPF was used as a marker to detect subclinical embryonic loss in women treated with CC with/without gonadotropins. In some of the women treated with CC, conception was assisted by artificial insemination with husband's semen (AIH). Our results have indicated that fertilization occurred (EPF + ve) in 47.7% (52/109) of women treated with CC with/without gonadotropins; 13.46% (7/52) retained the fetus and continued pregnancy till full term, whereas 78.9% (41/52) did not retain the fetuses. In the group where after stimulation, conception was assisted by AIH, fertilization was observed in 38.24% (26/68), retention in 11.54% (3/26) but subclinical embryonic loss was observed in 80.8% (21/26) cases. Thus, our results have indicated that subclinical embryonic loss may account for some of the discrepancy observed between the apparently normal ovulation and the pregnancy rates in women treated with clomiphene citrate.

The business of human embryonic stem cell research and an international analysis of relevant laws.

PubMed

De Trizio, Ella; Brennan, Christopher S

2004-01-01

Few sciences have held out such therapeutic promise and correspondingly stirred so much controversy in countries throughout the world as the developing science surrounding human embryonic stem cells. Since the first reported development of several lines of human embryonic stem cells in 1988, many governments around the world have attempted to address the thorny ethical issues raised by human embryonic stem cell research by the passage of laws. In some cases these laws have directly regulated governmental funding of the science; in other cases they have created a legal environment that has either encouraged or discouraged both governmental and private funding of the science. This article first differentiates human embryonic stem cells from other types of stem cells and frames the ethical controversy surrounding human embryonic stem cell research, then surveys laws governing human embryonic stem cell research in various scientifically advanced countries located throughout the Pacific Rim, Europe and North America and explains the impact these laws have had on governmental and private funding of human embryonic stem cell research.

The effect of silver nanoparticles on zebrafish embryonic development and toxicology.

PubMed

Xia, Guangqing; Liu, Tiantian; Wang, Zhenwei; Hou, Yi; Dong, Lihong; Zhu, Junyi; Qi, Jie

2016-06-01

The unique physical and chemical characteristics of nanomaterials, such as the effects of their small size, surface effects, very high rates of reaction, and quantum tunnel effect, have aroused great interest among scholars. However, improper usage has led to an increasing number of nanomaterials entering the environment through various channels, greatly threatening the security of the ecological environment and human health. The urgent need for a scientific assessment of their biosafety can enable nanomaterials to truly benefit humanity. However, the current research in this field is extremely limited with regard to safety standards and waste disposal. In this study, we used silver nanoparticles (nano-Ag) and zebrafish embryos as experimental subjects, and we have reported the deleterious effect on zebrafish embryos treated with different concentrations of nano-Ag, with respect to morphological features (mortality, deformity rate, and heartbeat) and the analysis of expression of relevant genes (sox17, gsc, ntl, otx2); we found a dose-dependent increase in mortality and hatching delay. The results of in situ hybridization indicated that nano-Ag causes a dose-dependent toxicity in embryonic development, and would affect their development and lead to deformity, delayed development, and even death. The safety limit for the concentration of nano-Ag was found to be less than 5 mg/L.

Thyroid Hormones Reduce Incubation Period without Developmental or Metabolic Costs in Murray River Short-Necked Turtles (Emydura macquarii).

PubMed

McGlashan, Jessica K; Thompson, Michael B; Van Dyke, James U; Spencer, Ricky-John

Metabolic processes are affected by both temperature and thyroid hormones in ectothermic vertebrates. Temperature is the major determinant of incubation length in oviparous vertebrates, but turtles can also alter developmental rate independent of temperature. Temperature gradients within natural nests cause different developmental rates of turtle embryos within nests. Despite temperature-induced reductions in developmental rate, cooler-incubated neonates often hatch synchronously with warmer siblings via metabolic compensation. The physiological mechanisms underlying metabolic compensation are unknown, but thyroid hormones may play a critical role. We applied excess triiodothyronine (T 3 ) to developing eggs of Murray River short-necked turtle (Emydura macquarii)-a species that exhibits metabolic compensation and synchronous hatching-to determine whether T 3 influences developmental rate and whether changes to incubation period incur metabolic costs. We measured heart rate, oxygen consumption and incubation period of eggs, and morphology and performance of hatchlings. Embryos that were exposed to T 3 pipped up to 3.5 d earlier than untreated controls, despite no change in total metabolic expenditure, and there were no treatment differences in hatchling morphology. Hatchlings treated with T 3 demonstrated similar righting ability to hatchlings from the control groups. Exposure to T 3 shortens incubation length by accelerating embryonic development but without statistically increasing embryonic metabolism. Thus, T 3 is a mechanism that cooler-incubated reptiles could use to accelerate their development to allow synchronous hatching with their warmer clutch mates but at little or no metabolic cost. Thus, metabolic compensation for synchronous hatching may not be metabolically expensive if T 3 is the underlying mechanism.

Treatment with acetyl-l-carnitine during in vitro maturation of buffalo oocytes improves oocyte quality and subsequent embryonic development.

PubMed

Xu, Hui-Yan; Yang, Xiao-Gan; Lu, Sheng-Sheng; Liang, Xing-Wei; Lu, Yang-Qing; Zhang, Ming; Lu, Ke-Huan

2018-06-01

Oocyte quality is one of the important factors in female fertility, in vitro maturation (IVM), and subsequent embryonic development. In the present study, we assessed whether acetyl-l-carnitine (ALC) supplementation during in vitro maturation of buffalo oocytes could improve oocyte quality and subsequent embryonic development. To determine the optimal level of ALC supplementation, we matured cumulus-oocyte complexes in maturation medium supplemented with 0, 2.5, and 5 mM ALC. The oocytes with a polar body were selected for parthenogenetic activation (PA) and in vitro fertilization (IVF). We found that oocytes matured in 2.5 mM ALC had significantly higher PA blastocyst rate (P < 0.05) and blastocyst cell number than those of unsupplemented oocytes (P < 0.05) and a significantly higher IVF blastocyst rate than that of oocytes matured in 5 mM ALC (P < 0.05). In all further experiments, we supplemented the maturation medium with 2.5 mM ALC. We then tested whether ALC supplementation could improve various markers of oocytes and cumulus cells. We compared cell proliferation; concentrations of reactive oxygen species (ROS), intracellular ATP, estradiol, and progesterone; mitochondrial distribution; mitochondrial DNA copy number (mtDNA); and expression levels of four genes encoding oocyte-derived factors (GDF9, BMP15) and steroid hormones (StAR, P450scc) between the supplemented and unsupplemented oocytes and cumulus cells. Cumulus cells matured with ALC supplementation were more prolific than those matured without ALC supplementation (P < 0.05). Oocytes treated with ALC had lower concentrations of intracellular ROS (P < 0.05) and a higher rate of diffuse mitochondrial distributions (P < 0.05) than those of untreated oocytes. Additionally, the mtDNA was higher in the ALC-treated oocytes (P < 0.05) and cumulus cells (P < 0.05) than that in the untreated cells. The ALC-treated maturation medium had a higher postmaturation concentration of estradiol than that of the untreated medium (P < 0.05). Finally, the gene expression levels of P450scc and GDF9 were greater in ALC-treated oocytes and cumulus cells than those in untreated cells (P < 0.05). Therefore, in buffalo, our results suggest that ALC affects mitochondrial function, regulates oocyte-derived paracrine factors, and increases the production of steroid hormones, leading to increased quality of matured oocytes and improved embryonic development in vitro. Copyright © 2018 Elsevier Inc. All rights reserved.

Time dependent effect of chronic embryonic exposure to ethanol on zebrafish: Morphology, biochemical and anxiety alterations.

PubMed

Ramlan, Nurul Farhana; Sata, Nurul Syafida Asma Mohd; Hassan, Siti Norhidayah; Bakar, Noraini Abu; Ahmad, Syahida; Zulkifli, Syaizwan Zahmir; Abdullah, Che Azurahanim Che; Ibrahim, Wan Norhamidah Wan

2017-08-14

Exposure to ethanol during critical period of development can cause severe impairments in the central nervous system (CNS). This study was conducted to assess the neurotoxic effects of chronic embryonic exposure to ethanol in the zebrafish, taking into consideration the time dependent effect. Two types of exposure regimen were applied in this study. Withdrawal exposure group received daily exposure starting from gastrulation until hatching, while continuous exposure group received daily exposure from gastrulation until behavioural assessment at 6dpf (days post fertilization). Chronic embryonic exposure to ethanol decreased spontaneous tail coiling at 24hpf (hour post fertilization), heart rate at 48hpf and increased mortality rate at 72hpf. The number of apoptotic cells in the embryos treated with ethanol was significantly increased as compared to the control. We also measured the morphological abnormalities and the most prominent effects can be observed in the treated embryos exposed to 1.50% and 2.00%. The treated embryos showed shorter body length, larger egg yolk, smaller eye diameter and heart edema as compared to the control. Larvae received 0.75% continuous ethanol exposure exhibited decreased swimming activity and increased anxiety related behavior, while withdrawal ethanol exposure showed increased swimming activity and decreased anxiety related behavior as compared to the respective control. Biochemical analysis exhibited that ethanol exposure for both exposure regimens altered proteins, lipids, carbohydrates and nucleic acids of the zebrafish larvae. Our results indicated that time dependent effect of ethanol exposure during development could target the biochemical processes thus leading to induction of apoptosis and neurobehavioral deficits in the zebrafish larvae. Thus it raised our concern about the safe limit of alcohol consumption for pregnant mother especially during critical periods of vulnerability for developing nervous system. Copyright © 2017 Elsevier B.V. All rights reserved.

Automated assessment of blood flow in developing embryonic hearts by extending dynamic range of Doppler OCT using a MHz FDML swept laser source (Conference Presentation)

NASA Astrophysics Data System (ADS)

Elahi, Sahar; Thrane, Lars; Rollins, Andrew M.; Jenkins, Michael W.

2017-02-01

Altered hemodynamics in developing embryonic hearts lead to congenital heart diseases, motivating close monitoring of blood flow over several stages of development. Doppler OCT can assess blood flow in tubular hearts, but the maximum velocity increases drastically during the period of cardiac cushion (valve precursors) formation. Therefore, the limited dynamic range of Doppler OCT velocity measurement makes it difficult to conduct longitudinal studies without phase wrapping at high velocities or loss of sensitivity to slow velocities. We have built a high-speed OCT system using an FDML laser (Optores GmbH, Germany) at a sweep rate of 1.68 MHz (axial resolution - 12 μm, sensitivity - 105 dB, phase stability - 17 mrad). The speed of this OCT system allows us to acquire high-density B-scans to obtain an extended velocity dynamic range without sacrificing the frame rate. The extended dynamic range within a frame is achieved by varying the A-scan interval at which the phase difference is found, enabling detection of velocities ranging from tens of microns per second to hundreds of mm per second. The extra lines in a frame can also be utilized to improve the structural and Doppler images via complex averaging. In structural images where presence of blood causes additional scattering, complex averaging helps retrieve features located deeper in the tissue. Moreover, high-density frames can be registered to 4D volumes to determine the orthogonal direction of flow and calculate shear stress. In conclusion, our high-speed OCT system will enable automated Doppler imaging of embryonic hearts in cohort studies.

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.

Derivation of Multipotent Mesenchymal Precursors from Human Embryonic Stem Cells

PubMed Central

Barberi, Tiziano; Willis, Lucy M; Socci, Nicholas D; Studer, Lorenz

2005-01-01

Background Human embryonic stem cells provide access to the earliest stages of human development and may serve as a source of specialized cells for regenerative medicine. Thus, it becomes crucial to develop protocols for the directed differentiation of embryonic stem cells into tissue-restricted precursors. Methods and Findings Here, we present culture conditions for the derivation of unlimited numbers of pure mesenchymal precursors from human embryonic stem cells and demonstrate multilineage differentiation into fat, cartilage, bone, and skeletal muscle cells. Conclusion Our findings will help to elucidate the mechanism of mesoderm specification during embryonic stem cell differentiation and provide a platform to efficiently generate specialized human mesenchymal cell types for future clinical applications. PMID:15971941

Elevated temperature enhances normal early embryonic development in the coral Platygyra acuta under low salinity conditions

NASA Astrophysics Data System (ADS)

Chui, Apple Pui Yi; Ang, Put

2015-06-01

To better understand the possible consequences of climate change on reef building scleractinian corals in a marginal environment, laboratory experiments were conducted to examine the interactive effects of changes in salinity and temperature on percent fertilization success and early embryonic development of the coral Platygyra acuta. In the present study, a salinity of 24 psu (ambient 32 psu) reduced fertilization success by 60 %. Normal embryonic development was reduced by >80 % at 26 psu (ambient 33 psu) with 100 % abnormal development at 22 psu under ambient temperature. Elevated temperature (+3 °C) above the ambient spawning temperature did not show any negative effects on fertilization success. However, there was a trend for more abnormal embryos to develop at elevated temperature in the 2 d of the spawning event. The interactive effects between salinity and temperature are statistically significant only on normal embryonic development of P. acuta, but not on its fertilization success. Salinity was revealed to be the main factor affecting both fertilization success and normal embryonic development. Interestingly, the much lower fertilization success (76 %) observed in the second day of spawning (Trial 2) under ambient temperature recovered to 99 % success under elevated (+3 °C) temperature conditions. Moreover, elevated temperature enhanced normal early embryonic development under lowered salinity (26 psu). This antagonistic interactive effect was consistently observed in two successive nights of spawning. Overall, our results indicate that, in terms of its fertilization success and embryonic development, P. acuta is the most tolerant coral species to reduced salinity thus far reported in the literature. Elevated temperature, at least that within the tolerable range of the corals, could apparently alleviate the potential negative effects from salinity stresses. This mitigating role of elevated temperature appears not to have been reported on corals before.

Use of field-portable ultrasonography reveals differences in developmental phenology and maternal egg provisioning in two sympatric viviparous snakes.

PubMed

Sparkman, Amanda M; Chism, Kenneth R; Bronikowski, Anne M; Brummett, Lilly J; Combrink, Lucia L; Davis, Courtney L; Holden, Kaitlyn G; Kabey, Nicole M; Miller, David A W

2018-03-01

A thorough understanding of the life cycles underlying the demography of wild species is limited by the difficulty of observing hidden life-history traits, such as embryonic development. Major aspects of embryonic development, such as the rate and timing of development, and maternal-fetal interactions can be critical features of early-life fitness and may impact population trends via effects on individual survival. While information on development in wild snakes and lizards is particularly limited, the repeated evolution of viviparity and diversity of reproductive mode in this clade make it a valuable subject of study. We used field-portable ultrasonography to investigate embryonic development in two sympatric garter snake species, Thamnophis sirtalis and Thamnophis elegans in the Sierra Nevada mountains of California. This approach allowed us to examine previously hidden reproductive traits including the timing and annual variation in development and differences in parental investment in young. Both species are viviparous, occupy similar ecological niches, and experience the same annual environmental conditions. We found that T. sirtalis embryos were more developmentally advanced than T. elegans embryos during June of three consecutive years. We also found that eggs increased in volume more substantially across developmental stages in T. elegans than in T. sirtalis , indicating differences in maternal provisioning of embryos via placental transfer of water. These findings shed light on interspecific differences in parental investment and timing of development within the same environmental context and demonstrate the value of field ultrasonography for pursuing questions relating to the evolution of reproductive modes, and the ecology of development.

Development of an invitro technique to use mouse embryonic stem cell in evaluating effects of xenobiotics

EPA Science Inventory

Our goal has been to develop a high-throughput, in vitro technique for evaluating the effects of xenobiotics using mouse embryonic stem cells (mESCs). We began with the Embryonic Stem Cell Test (EST), which is used to predict the embryotoxic potential of a test compound by combin...

High- and low-temperature manipulation during late incubation: effects on embryonic development, the hatching process, and metabolism in broilers.

PubMed

Willemsen, H; Kamers, B; Dahlke, F; Han, H; Song, Z; Ansari Pirsaraei, Z; Tona, K; Decuypere, E; Everaert, N

2010-12-01

Temperatures continuously higher and lower than the standard incubation temperature by 3°C from embryonic d 16 until embryonic d 18.5 result in differential effects on embryonic development, the hatching process, and embryonic metabolism. Embryos in the high-temperature group were forced into a state of malnutrition by the temperature treatment, as reflected by reduced embryo growth and yolk consumption, resulting in a significantly lower chick weight at hatch. In addition, altered air cell and blood gases as well as a retarded hatching process further indicated reduced growth of embryos exposed to higher incubation temperatures during the latter part of incubation. In addition, hatchability was significantly reduced by the high-temperature treatment due to higher embryonic mortality during the treatment period and the hatching process. Levels of blood glucose, lactate, liver glycogen, plasma triglycerides, and nonesterified fatty acids indicated an altered carbohydrate and lipid metabolism for the high-temperature group. Although the hatching process of embryos exposed to lower incubation temperatures was also significantly retarded, their embryonic development and growth were strikingly similar to those of the control group.

Rationally optimized cryopreservation of multiple mouse embryonic stem cell lines: I--Comparative fundamental cryobiology of multiple mouse embryonic stem cell lines and the implications for embryonic stem cell cryopreservation protocols.

PubMed

Kashuba, Corinna M; Benson, James D; Critser, John K

2014-04-01

The post-thaw recovery of mouse embryonic stem cells (mESCs) is often assumed to be adequate with current methods. However as this publication will show, this recovery of viable cells actually varies significantly by genetic background. Therefore there is a need to improve the efficiency and reduce the variability of current mESC cryopreservation methods. To address this need, we employed the principles of fundamental cryobiology to improve the cryopreservation protocol of four mESC lines from different genetic backgrounds (BALB/c, CBA, FVB, and 129R1 mESCs) through a comparative study characterizing the membrane permeability characteristics and membrane integrity osmotic tolerance limits of each cell line. In the companion paper, these values were used to predict optimal cryoprotectants, cooling rates, warming rates, and plunge temperatures, and then these predicted optimal protocols were validated against standard freezing protocols. Copyright © 2014 Elsevier Inc. All rights reserved.

[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.

A novel approach for studying the temporal modulation of embryonic skeletal development using organotypic bone cultures and microcomputed tomography.

PubMed

Kanczler, Janos M; Smith, Emma L; Roberts, Carol A; Oreffo, Richard O C

2012-10-01

Understanding the structural development of embryonic bone in a three dimensional framework is fundamental to developing new strategies for the recapitulation of bone tissue in latter life. We present an innovative combined approach of an organotypic embryonic femur culture model, microcomputed tomography (μCT) and immunohistochemistry to examine the development and modulation of the three dimensional structures of the developing embryonic femur. Isolated embryonic chick femurs were organotypic (air/liquid interface) cultured for 10 days in either basal, chondrogenic, or osteogenic supplemented culture conditions. The growth development and modulating effects of basal, chondrogenic, or osteogenic culture media of the embryonic chick femurs was investigated using μCT, immunohistochemistry, and histology. The growth and development of noncultured embryonic chick femur stages E10, E11, E12, E13, E15, and E17 were very closely correlated with increased morphometric indices of bone formation as determined by μCT. After 10 days in the organotpyic culture set up, the early aged femurs (E10 and E11) demonstrated a dramatic response to the chondrogenic or osteogenic culture conditions compared to the basal cultured femurs as determined by a change in μCT morphometric indices and modified expression of chondrogenic and osteogenic markers. Although the later aged femurs (E12 and E13) increased in size and structure after 10 days organotpypic culture, the effects of the osteogenic and chondrogenic organotypic cultures on these femurs were not significantly altered compared to basal conditions. We have demonstrated that the embryonic chick femur organotpyic culture model combined with the μCT and immunohistochemical analysis can provide an integral methodology for investigating the modulation of bone development in an ex vivo culture setting. Hence, these interdisciplinary techniques of μCT and whole organ bone cultures will enable us to delineate some of the temporal, structural developmental paradigms and modulation of bone tissue formation to underpin innovative skeletal regenerative technology for clinical therapeutic strategies in musculoskeletal trauma and diseases.

Functional characterization of human pluripotent stem cell-derived arterial endothelial cells.

PubMed

Zhang, Jue; Chu, Li-Fang; Hou, Zhonggang; Schwartz, Michael P; Hacker, Timothy; Vickerman, Vernella; Swanson, Scott; Leng, Ning; Nguyen, Bao Kim; Elwell, Angela; Bolin, Jennifer; Brown, Matthew E; Stewart, Ron; Burlingham, William J; Murphy, William L; Thomson, James A

2017-07-25

Here, we report the derivation of arterial endothelial cells from human pluripotent stem cells that exhibit arterial-specific functions in vitro and in vivo. We combine single-cell RNA sequencing of embryonic mouse endothelial cells with an EFNB2-tdTomato/EPHB4-EGFP dual reporter human embryonic stem cell line to identify factors that regulate arterial endothelial cell specification. The resulting xeno-free protocol produces cells with gene expression profiles, oxygen consumption rates, nitric oxide production levels, shear stress responses, and TNFα-induced leukocyte adhesion rates characteristic of arterial endothelial cells. Arterial endothelial cells were robustly generated from multiple human embryonic and induced pluripotent stem cell lines and have potential applications for both disease modeling and regenerative medicine.

[Correlation of the DNA fragmentation index and malformation rate of optimized sperm with embryonic development and early spontaneous abortion in IVF-ET].

PubMed

Jiang, Wei-Jie; Jin, Fan; Zhou, Li-Ming

2016-06-01

To investigate the effects of the DNA fragmentation index (DFI) and malformation rate (SMR) of optimized sperm on embryonic development and early spontaneous abortion in conventional in vitro fertilization and embryo transfer (IVF-ET). We selected 602 cycles of conventional IVF-ET for pure oviductal infertility that had achieved clinical pregnancies, including 505 cycles with ongoing pregnancy and 97 cycles with early spontaneous abortion. On the day of ovum retrieval, we examined the DNA integrity and morphology of the rest of the optimized sperm using the SCD and Diff-Quik methods, established the joint predictor (JP) by logistic equation, and assessed the value of DFI and SMR in predicting early spontaneous abortion using the ROC curve. The DFI, SMR, and high-quality embryo rate were (15.91±3.69)%, (82.85±10.24)%, and 46.53% (342/735) in the early spontaneous abortion group and (9.30±4.22)%, (77.32±9.19)%, and 56.43% (2263/4010) respectively in the ongoing pregnancy group, all with statistically significant differences between the two groups (P<0.05 ). Both the DFI and SMR were the risk factors of early spontaneous abortion (OR = 5.96 and 1.66; both P< 0.01). The areas under the ROC curve for DFI, SMR and JP were 0.893±0.019, 0.685±0.028, and 0.898±0.018, respectively. According to the Youden index, the optimal cut-off values of the DFI and SMR obtained for the prediction of early spontaneous abortion were approximately 15% and 80%. The DFI was correlated positively with SMR (r= 0.31, P<0.01) but the high-quality embryo rate negatively with both the DFI (r= －0.45, P<0.01) and SMR (r= －0.22, P<0.01). The DFI and SMR of optimized sperm are closely associated with embryonic development in IVF. The DFI has a certain value for predicting early spontaneous abortion with a threshold of approximately 15%, but SMR may have a lower predictive value.

Optical tracking of embryonic vertebrates behavioural responses using automated time-resolved video-microscopy system

NASA Astrophysics Data System (ADS)

Walpitagama, Milanga; Kaslin, Jan; Nugegoda, Dayanthi; Wlodkowic, Donald

2016-12-01

The fish embryo toxicity (FET) biotest performed on embryos of zebrafish (Danio rerio) has gained significant popularity as a rapid and inexpensive alternative approach in chemical hazard and risk assessment. The FET was designed to evaluate acute toxicity on embryonic stages of fish exposed to the test chemical. The current standard, similar to most traditional methods for evaluating aquatic toxicity provides, however, little understanding of effects of environmentally relevant concentrations of chemical stressors. We postulate that significant environmental effects such as altered motor functions, physiological alterations reflected in heart rate, effects on development and reproduction can occur at sub-lethal concentrations well below than LC10. Behavioral studies can, therefore, provide a valuable integrative link between physiological and ecological effects. Despite the advantages of behavioral analysis development of behavioral toxicity, biotests is greatly hampered by the lack of dedicated laboratory automation, in particular, user-friendly and automated video microscopy systems. In this work we present a proof-of-concept development of an optical system capable of tracking embryonic vertebrates behavioral responses using automated and vastly miniaturized time-resolved video-microscopy. We have employed miniaturized CMOS cameras to perform high definition video recording and analysis of earliest vertebrate behavioral responses. The main objective was to develop a biocompatible embryo positioning structures that were suitable for high-throughput imaging as well as video capture and video analysis algorithms. This system should support the development of sub-lethal and behavioral markers for accelerated environmental monitoring.

Identification and characterization of secondary neural tube-derived embryonic neural stem cells in vitro.

PubMed

Shaker, Mohammed R; Kim, Joo Yeon; Kim, Hyun; Sun, Woong

2015-05-15

Secondary neurulation is an embryonic progress that gives rise to the secondary neural tube, the precursor of the lower spinal cord region. The secondary neural tube is derived from aggregated Sox2-expressing neural cells at the dorsal region of the tail bud, which eventually forms rosette or tube-like structures to give rise to neural tissues in the tail bud. We addressed whether the embryonic tail contains neural stem cells (NSCs), namely secondary NSCs (sNSCs), with the potential for self-renewal in vitro. Using in vitro neurosphere assays, neurospheres readily formed at the rosette and neural-tube levels, but less frequently at the tail bud tip level. Furthermore, we identified that sNSC-generated neurospheres were significantly smaller in size compared with cortical neurospheres. Interestingly, various cell cycle analyses revealed that this difference was not due to a reduction in the proliferation rate of NSCs, but rather the neuronal commitment of sNSCs, as sNSC-derived neurospheres contain more committed neuronal progenitor cells, even in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). These results suggest that the higher tendency for sNSCs to spontaneously differentiate into progenitor cells may explain the limited expansion of the secondary neural tube during embryonic development.

The Most Prevalent Freeman-Sheldon Syndrome Mutations in the Embryonic Myosin Motor Share Functional Defects.

PubMed

Walklate, Jonathan; Vera, Carlos; Bloemink, Marieke J; Geeves, Michael A; Leinwand, Leslie

2016-05-06

The embryonic myosin isoform is expressed during fetal development and rapidly down-regulated after birth. Freeman-Sheldon syndrome (FSS) is a disease associated with missense mutations in the motor domain of this myosin. It is the most severe form of distal arthrogryposis, leading to overcontraction of the hands, feet, and orofacial muscles and other joints of the body. Availability of human embryonic muscle tissue has been a limiting factor in investigating the properties of this isoform and its mutations. Using a recombinant expression system, we have studied homogeneous samples of human motors for the WT and three of the most common FSS mutants: R672H, R672C, and T178I. Our data suggest that the WT embryonic myosin motor is similar in contractile speed to the slow type I/β cardiac based on the rate constant for ADP release and ADP affinity for actin-myosin. All three FSS mutations show dramatic changes in kinetic properties, most notably the slowing of the apparent ATP hydrolysis step (reduced 5-9-fold), leading to a longer lived detached state and a slowed Vmax of the ATPase (2-35-fold), indicating a slower cycling time. These mutations therefore seriously disrupt myosin function. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Proximate effects of temperature versus evolved intrinsic constraints for embryonic development times among temperate and tropical songbirds

USGS Publications Warehouse

Ton, Riccardo; Martin, Thomas E.

2017-01-01

The relative importance of intrinsic constraints imposed by evolved physiological trade-offs versus the proximate effects of temperature for interspecific variation in embryonic development time remains unclear. Understanding this distinction is important because slow development due to evolved trade-offs can yield phenotypic benefits, whereas slow development from low temperature can yield costs. We experimentally increased embryonic temperature in free-living tropical and north temperate songbird species to test these alternatives. Warmer temperatures consistently shortened development time without costs to embryo mass or metabolism. However, proximate effects of temperature played an increasingly stronger role than intrinsic constraints for development time among species with colder natural incubation temperatures. Long development times of tropical birds have been thought to primarily reflect evolved physiological trade-offs that facilitate their greater longevity. In contrast, our results indicate a much stronger role of temperature in embryonic development time than currently thought.

Short periods of incubation, egg turning during storage and broiler breeder hens age for early development of embryos, hatching results, chicks quality and juvenile growth.

PubMed

Damaziak, K; Paweska, M; Gozdowski, D; Niemiec, J

2018-05-14

An effect of modification of storage conditions of the eggs of broiler breeder flocks at the age of 49-, 52- and 70-, 73-wks of life on an early embryonic development, hatching time and synchronization, hatchability rates, chicks quality and broiler growth was investigated. The eggs were divided into 4 experimental groups: COI = eggs storage 5 d, at turning every 12 h; NSP = eggs storage 12 d, at turning every 12 h; SPIDES = were treated with 4 h pre-incubation at 30°C and 50-55% air humidity, delivered at 5 and 10 d over of 12 d of storage, and turning every 12 h; NCOI = eggs storage 12 d, no turning and no pre-incubation. Eggs from older hens were characterized by poorer hatchability and poorer chicks quality. The use of 2 × 4 h pre-incubation in 12 d of eggs storage could have an effect on the initial acceleration of embryonic development in eggs of young hens, contributing to the alignment of embryos development in eggs from young and older hens to 72 h of incubation. Pre-incubation had no effect on the length of incubation period, hatching window, but it increased the hatchability of the set and apparently fertilized eggs and decreased the number of eggs not hatched, and also improved chicks quality. Eggs turning by 90° every 12 h during the storage positively affected the embryonic development, shortening the incubation time and the quality of chicks, but had no effect on hatchability rates and body weight in 42 d of life. Based on the obtained results, it can be concluded that the applied modifications can be effective in counteracting the negative effects of storage of hatching eggs from both young and older birds.

Effects of temperature on embryonic development of lake herring (Coregonus artedii)

USGS Publications Warehouse

Colby, Peter J.; Brooke, L.T.

1973-01-01

Embryonic development of lake herring (Coregonus artedii) was observed in the laboratory at 13 constant temperatures from 0.0 to 12.1 C and in Pickerel Lake (Washtenaw County, Michigan) at natural temperature regimes. Rate of development during incubation was based on progression of the embryos through 20 identifiable stages. An equation was derived to predict development stage at constant temperatures, on the general assumption that development stage (DS) is a function of time (days, D) and temperature (T). The equation should also be useful in interpreting estimates from future regressions that include other environmental variables that affect egg development. A second regression model, derived primarily for fluctuating temperatures, related development rate for stage j (DRj), expressed as the reciprocal of time, to temperature (x). The generalized equation for a development stage is: DRj = abx cx2 dx3. In general, time required for embryos to reach each stage of development in Pickerel Lake agreed closely with the time predicted from this equation, derived from our laboratory observations. Hatching time was predicted within 1 day in 1969 and within 2 days in 1970. We used the equations derived with the second model to predict the effect of the superimposition of temperature increases of 1 and 2 C on the measured temperatures in Pickerel Lake. Conceivably, hatching dates could be affected sufficiently to jeopardize the first feeding of lake herring through loss of harmony between hatching date and seasonal food availability.

The effect of low-density diets on broiler breeder performance during the laying period and on embryonic development of their offspring.

PubMed

Enting, H; Kruip, T A M; Verstegen, M W A; van der Aar, P J

2007-05-01

The effect of low-density diets on bird performance, egg composition, and embryonic development was studied with 2,100 female and 210 male Cobb broiler breeders from 25 to 60 wk of age. The experiment included 5 treatments. These included a control group with a normal density diet (ND, 2,800 kcal of AME/kg). Treatments 2 (LD11) and 3 (LD21) had a 11 and 21% lower nutrient density. Treatment 4 (LD11(OP)) had a 11% less dense diet, which was obtained by inclusion of other feed ingredients. In these 4 treatments similar diets were given during the rearing and the laying period. Treatment 5 combined LD12 in the rearing period and ND diets during the laying period (LD12-ND). Egg composition and embryonic development were measured in eggs of ND and LD21 birds at 29 and 41 wk of age. During the laying period from wk 25 to 60, live weights did not differ among treatments, except that birds fed LD11(OP) had lower live weights. A significantly higher rate of lay was provided by LD11 compared with ND. Egg weights were significantly higher when low-density diets were fed, particularly in LD11(OP). Percentage of fertile eggs did not differ among treatments. Compared with the other treatments, LD11(OP) provided a significantly lower hatchability. We found that LD21 resulted in a better development of the area vitellina externa and heart and embryo weight at 29 wk of age. It was concluded that this was related to a higher egg weight and egg white proportion. This suggests that the amount of egg white in eggs of hens fed ND was limiting for embryonic development, particularly in eggs of young broiler breeders.

The rate of X-ray-induced DNA double-strand break repair in the embryonic mouse brain is unaffected by exposure to 50 Hz magnetic fields.

PubMed

Woodbine, Lisa; Haines, Jackie; Coster, Margaret; Barazzuol, Lara; Ainsbury, Elizabeth; Sienkiewicz, Zenon; Jeggo, Penny

2015-06-01

Following in utero exposure to low dose radiation (10-200 mGy), we recently observed a linear induction of DNA double-strand breaks (DSB) and activation of apoptosis in the embryonic neuronal stem/progenitor cell compartment. No significant induction of DSB or apoptosis was observed following exposure to magnetic fields (MF). In the present study, we exploited this in vivo system to examine whether exposure to MF before and after exposure to 100 mGy X-rays impacts upon DSB repair rates. 53BP1 foci were quantified following combined exposure to radiation and MF in the embryonic neuronal stem/progenitor cell compartment. Embryos were exposed in utero to 50 Hz MF at 300 μT for 3 h before and up to 9 h after exposure to 100 mGy X-rays. Controls included embryos exposed to MF or X-rays alone plus sham exposures. Exposure to MF before and after 100 mGy X-rays did not impact upon the rate of DSB repair in the embryonic neuronal stem cell compartment compared to repair rates following radiation exposure alone. We conclude that in this sensitive system MF do not exert any significant level of DNA damage and do not impede the repair of X-ray induced damage.

Transforming Growth Factor Beta (TGFβ1, TGFβ2 and TGFβ3) Null-Mutant Phenotypes in Embryonic Gonadal Development

PubMed Central

Memon, Mushtaq A.; Anway, Matthew D.; Covert, Trevor R.; Uzumcu, Mehmet; Skinner, Michael K.

2008-01-01

The role transforming growth factor beta (TGFb) isoforms TGFb1, TGFb2 and TGFb3 have in the regulation of embryonic gonadal development was investigated with the use of null-mutant (i.e. knockout) mice for each of the TGFb isoforms. Late embryonic gonadal development was investigated because homozygote TGFb null-mutant mice generally die around birth, with some embryonic loss as well. In the testis, the TGFb1 null-mutant mice had a decrease in the number of germ cells at birth, postnatal day 0 (P0). In the testis, the TGFb2 null-mutant mice had a decrease in the number of seminiferous cords at embryonic day 15 (E15). In the ovary, the TGFb2 null-mutant mice had an increase in the number of germ cells at P0. TGFb isoforms appear to have a role in gonadal development, but interactions between the isoforms is speculated to compensate in the different TGFb isoform null-mutant mice. PMID:18790002

TEAD and YAP regulate the enhancer network of human embryonic pancreatic progenitors.

PubMed

Cebola, Inês; Rodríguez-Seguí, Santiago A; Cho, Candy H-H; Bessa, José; Rovira, Meritxell; Luengo, Mario; Chhatriwala, Mariya; Berry, Andrew; Ponsa-Cobas, Joan; Maestro, Miguel Angel; Jennings, Rachel E; Pasquali, Lorenzo; Morán, Ignasi; Castro, Natalia; Hanley, Neil A; Gomez-Skarmeta, Jose Luis; Vallier, Ludovic; Ferrer, Jorge

2015-05-01

The genomic regulatory programmes that underlie human organogenesis are poorly understood. Pancreas development, in particular, has pivotal implications for pancreatic regeneration, cancer and diabetes. We have now characterized the regulatory landscape of embryonic multipotent progenitor cells that give rise to all pancreatic epithelial lineages. Using human embryonic pancreas and embryonic-stem-cell-derived progenitors we identify stage-specific transcripts and associated enhancers, many of which are co-occupied by transcription factors that are essential for pancreas development. We further show that TEAD1, a Hippo signalling effector, is an integral component of the transcription factor combinatorial code of pancreatic progenitor enhancers. TEAD and its coactivator YAP activate key pancreatic signalling mediators and transcription factors, and regulate the expansion of pancreatic progenitors. This work therefore uncovers a central role for TEAD and YAP as signal-responsive regulators of multipotent pancreatic progenitors, and provides a resource for the study of embryonic development of the human pancreas.

Ontogeny of osmoregulation in embryos of intertidal crabs (Hemigrapsus sexdentatus and H. crenulatus, Grapsidae, Brachyura): putative involvement of the embryonic dorsal organ.

PubMed

Seneviratna, Deepani; Taylor, H H

2006-04-01

This study examined whether the existence of hyperosmotic internal fluids in embryos of euryhaline crabs (Hemigrapsus sexdentatus and H. crenulatus) in dilute seawater reflects osmotic isolation due to impermeability of the egg envelope, as proposed for other decapods, or active osmoregulation. When ovigerous crabs with eggs at gastrula stage were transferred from 100% seawater (osmolality 1000 mmol kg(-1)) to 50% seawater, embryogenesis and hatching of zoea were completed normally, but were delayed. Hatching failed if the transfer to 50% seawater occurred before gastrulation, and embryogenesis was abnormal in 25% seawater. In 100% seawater, embryos at all stages were internally hyperosmotic by 150-250 mmol kg(-1). On transfer to 50% seawater, osmolality initially decreased but remained 200-350 mmol kg(-1) hyperosmotic to the medium for several weeks until hatching. High efflux rates of tritium-labelled water (t((1/2)) 16-75 min) and (22)Na (t(1/2) 109-374 min) from H. crenulatus embryos were inconsistent with the osmotic isolation hypothesis. It is concluded that post-gastrula embryos were actively hyper-osmoregulating. The diffusional water permeability of the embryos decreased during development while the sodium efflux rate increased 10-fold. Very rapidly exchanging pools of water and sodium (t(1/2) a few seconds to minutes) probably corresponded to peri-embryonic fluid and implied that the egg envelope was a negligible barrier to diffusion of water and salts. Higher Na(+)/K(+)-ATPase activities in late embryos of H. crenulatus incubated in 50% seawater than in embryos incubated in full strength seawater were consistent with an acclimation response. An area of the embryonic surface located over the yolk in the region of the embryonic dorsal organ stained with AgNO(3). Staining appeared at gastrulation, persisted throughout development and was lost at hatching. Deposits of AgCl between the outer and inner membranes, identified by X-ray microanalysis, suggest that the dorsal organ was a site of chloride extrusion. A model for osmoregulation in post-gastrula embryos is proposed: osmotic uptake of water is balanced by excretion of water and salts via the dorsal organ and salt loss is balanced by active uptake over the general embryonic ectoderm.

Monitoring p53 by MDM2 and MDMX is required for endocrine pancreas development and function in a spatio-temporal manner.

PubMed

Zhang, Yiwei; Zeng, Shelya X; Hao, Qian; Lu, Hua

2017-03-01

Although p53 is not essential for normal embryonic development, it plays a pivotal role in many biological and pathological processes, including cell fate determination-dependent and independent events and diseases. The expression and activity of p53 largely depend on its two biological inhibitors, MDM2 and MDMX, which have been shown to form a complex in order to tightly control p53 to an undetectable level during early stages of embryonic development. However, more delicate studies using conditional gene-modification mouse models show that MDM2 and MDMX may function separately or synergistically on p53 regulation during later stages of embryonic development and adulthood in a cell and tissue-specific manner. Here, we report the role of the MDM2/MDMX-p53 pathway in pancreatic islet morphogenesis and functional maintenance, using mouse lines with specific deletion of MDM2 or MDMX in pancreatic endocrine progenitor cells. Interestingly, deletion of MDM2 results in defects of embryonic endocrine pancreas development, followed by neonatal hyperglycemia and lethality, by inducing pancreatic progenitor cell apoptosis and inhibiting cell proliferation. However, unlike MDM2-knockout animals, mice lacking MDMX in endocrine progenitor cells develop normally. But, surprisingly, the survival rate of adult MDMX-knockout mice drastically declines compared to control mice, as blockage of neonatal development of endocrine pancreas by inhibition of cell proliferation and subsequent islet dysfunction and hyperglycemia eventually lead to type 1 diabetes-like disease with advanced diabetic nephropathy. As expected, both MDM2 and MDMX deletion-caused pancreatic defects are completely rescued by loss of p53, verifying the crucial role of the MDM2 and/or MDMX in regulating p53 in a spatio-temporal manner during the development, functional maintenance, and related disease progress of endocrine pancreas. Also, our study suggests a possible mouse model of advanced diabetic nephropathy, which is complementary to other established diabetic models and perhaps useful for the development of anti-diabetes therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

Convergent evolution of embryonic growth and development in the eastern fence lizard (Sceloporus undulatus).

PubMed

Oufieroi, Christopher E; Angilletta, Michael J

2006-05-01

Theory predicts that cold environments will select for strategies that enhance the growth of ectotherms, such as early emergence from nests and more efficient use of resources. We used a common garden experiment to detect parallel clines in rates of embryonic growth and development by eastern fence lizards (Sceloporus undulatus). Using realistic thermal conditions, we measured growth efficiencies and incubation periods of lizards from five populations representing two distinct clades. In both clades, embryos from cold environments (Indiana, New Jersey, and Virginia) grew more efficiently and hatched earlier than embryos from warm environments (Florida and South Carolina). Because eggs from cold environments were larger than eggs from warm environments, we experimentally miniaturized eggs from one population (Virginia) to determine whether rapid growth and development were caused by a greater maternal investment. Embryos in miniaturized eggs grew as efficiently and incubated for the same duration as embryos in unmanipulated eggs. Taken together, our results suggest countergradient variation has evolved at least twice in S. undulatus.

Cytotoxic Effects of Dillapiole on Embryonic Development of Mouse Blastocysts in Vitro and in Vivo

PubMed Central

Chan, Wen-Hsiung

2014-01-01

We examined the cytotoxic effects of dillapiole, a phenylpropanoid with antileishmanial, anti-inflammatory, antifungal, and acaricidal activities, on the blastocyst stage of mouse embryos, subsequent embryonic attachment and outgrowth in vitro, and in vivo implantation via embryo transfer. Blastocysts treated with 2.5–10 μM dillapiole exhibited a significant increase in apoptosis and corresponding decrease in total cell number. Notably, the implantation success rates of blastocysts pretreated with dillapiole were lower than those of their control counterparts. Moreover, in vitro treatment with 2.5–10 μM dillapiole was associated with increased resorption of post-implantation embryos and decreased fetal weight. Our results collectively indicate that dillapiole induces apoptosis and retards early post-implantation development, both in vitro and in vivo. However, the extent to which this organic compound exerts teratogenic effects on early human development is not known at present. Further studies are required to establish effective protection strategies against the cytotoxic effects of dillapiole. PMID:24933639

Utilization of ketone bodies by chick brain and spinal cord during embryonic and postnatal development.

PubMed

Linares, A; Caamaño, G J; Diaz, R; Gonzalez, F J; Garcia-Peregrin, E

1993-10-01

Lipid synthesis from acetoacetate and 3-hydroxybutyrate was studied in chick embryo from 15 to 21 days and in chick neonate from 1 to 21 days. Embryonic spinal cord showed higher ability than brain to incorporate acetoacetate into total lipids, although a sharp decrease was found at hatching. 3-Hydroxybutyrate incorporation into total lipids was also higher in spinal cord than in brain, especially during the embryonic period. Phospholipids were the main lipids formed in both tissues from both precursors. An appreciable percentage of radioactivity was also recovered as free cholesterol, especially during the embryonic phase. The developmental patterns of amino acid synthesis from acetoacetate and 3-hydroxybutyrate were similar in both tissues: a clear increase after hatching was followed by a decrease at day 4 of neonatal life. Acetoacetate was a better substrate for amino acid synthesis than 3-hydroxybutyrate during the embryonic development in both tissues. Oxidation of both precursors to CO2 strongly decreased between 15 and 21 days of embryonic development both in brain and spinal cord.

PTBP1 Is Required for Embryonic Development before Gastrulation

PubMed Central

Suckale, Jakob; Wendling, Olivia; Masjkur, Jimmy; Jäger, Melanie; Münster, Carla; Anastassiadis, Konstantinos; Stewart, A. Francis; Solimena, Michele

2011-01-01

Polypyrimidine-tract binding protein 1 (PTBP1) is an important cellular regulator of messenger RNAs influencing the alternative splicing profile of a cell as well as its mRNA stability, location and translation. In addition, it is diverted by some viruses to facilitate their replication. Here, we used a novel PTBP1 knockout mouse to analyse the tissue expression pattern of PTBP1 as well as the effect of its complete removal during development. We found evidence of strong PTBP1 expression in embryonic stem cells and throughout embryonic development, especially in the developing brain and spinal cord, the olfactory and auditory systems, the heart, the liver, the kidney, the brown fat and cartilage primordia. This widespread distribution points towards a role of PTBP1 during embryonic development. Homozygous offspring, identified by PCR and immunofluorescence, were able to implant but were arrested or retarded in growth. At day 7.5 of embryonic development (E7.5) the null mutants were about 5x smaller than the control littermates and the gap in body size widened with time. At mid-gestation, all homozygous embryos were resorbed/degraded. No homozygous mice were genotyped at E12 and the age of weaning. Embryos lacking PTBP1 did not display differentiation into the 3 germ layers and cavitation of the epiblast, which are hallmarks of gastrulation. In addition, homozygous mutants displayed malformed ectoplacental cones and yolk sacs, both early supportive structure of the embryo proper. We conclude that PTBP1 is not required for the earliest isovolumetric divisions and differentiation steps of the zygote up to the formation of the blastocyst. However, further post-implantation development requires PTBP1 and stalls in homozygous null animals with a phenotype of dramatically reduced size and aberration in embryonic and extra-embryonic structures. PMID:21423341

PTBP1 is required for embryonic development before gastrulation.

PubMed

Suckale, Jakob; Wendling, Olivia; Masjkur, Jimmy; Jäger, Melanie; Münster, Carla; Anastassiadis, Konstantinos; Stewart, A Francis; Solimena, Michele

2011-02-17

Polypyrimidine-tract binding protein 1 (PTBP1) is an important cellular regulator of messenger RNAs influencing the alternative splicing profile of a cell as well as its mRNA stability, location and translation. In addition, it is diverted by some viruses to facilitate their replication. Here, we used a novel PTBP1 knockout mouse to analyse the tissue expression pattern of PTBP1 as well as the effect of its complete removal during development. We found evidence of strong PTBP1 expression in embryonic stem cells and throughout embryonic development, especially in the developing brain and spinal cord, the olfactory and auditory systems, the heart, the liver, the kidney, the brown fat and cartilage primordia. This widespread distribution points towards a role of PTBP1 during embryonic development. Homozygous offspring, identified by PCR and immunofluorescence, were able to implant but were arrested or retarded in growth. At day 7.5 of embryonic development (E7.5) the null mutants were about 5x smaller than the control littermates and the gap in body size widened with time. At mid-gestation, all homozygous embryos were resorbed/degraded. No homozygous mice were genotyped at E12 and the age of weaning. Embryos lacking PTBP1 did not display differentiation into the 3 germ layers and cavitation of the epiblast, which are hallmarks of gastrulation. In addition, homozygous mutants displayed malformed ectoplacental cones and yolk sacs, both early supportive structure of the embryo proper. We conclude that PTBP1 is not required for the earliest isovolumetric divisions and differentiation steps of the zygote up to the formation of the blastocyst. However, further post-implantation development requires PTBP1 and stalls in homozygous null animals with a phenotype of dramatically reduced size and aberration in embryonic and extra-embryonic structures.

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

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.

Functional Analysis of the Drosophila Embryonic Germ Cell Transcriptome by RNA Interference

PubMed Central

Bujna, Ágnes; Vilmos, Péter; Spirohn, Kerstin; Boutros, Michael; Erdélyi, Miklós

2014-01-01

In Drosophila melanogaster, primordial germ cells are specified at the posterior pole of the very early embryo. This process is regulated by the posterior localized germ plasm that contains a large number of RNAs of maternal origin. Transcription in the primordial germ cells is actively down-regulated until germ cell fate is established. Bulk expression of the zygotic genes commences concomitantly with the degradation of the maternal transcripts. Thus, during embryogenesis, maternally provided and zygotically transcribed mRNAs determine germ cell development collectively. In an effort to identify novel genes involved in the regulation of germ cell behavior, we carried out a large-scale RNAi screen targeting both maternal and zygotic components of the embryonic germ line transcriptome. We identified 48 genes necessary for distinct stages in germ cell development. We found pebble and fascetto to be essential for germ cell migration and germ cell division, respectively. Our data uncover a previously unanticipated role of mei-P26 in maintenance of embryonic germ cell fate. We also performed systematic co-RNAi experiments, through which we found a low rate of functional redundancy among homologous gene pairs. As our data indicate a high degree of evolutionary conservation in genetic regulation of germ cell development, they are likely to provide valuable insights into the biology of the germ line in general. PMID:24896584

Low external pH replaces 2,4-D in maintaining and multiplying 2,4-D-initiated embryogenic cells of carrot

NASA Technical Reports Server (NTRS)

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

1990-01-01

A mixed culture comprised of both embryonic globules and nonembryogenic callus was derived from seedling hypocotyls of Daucus carota cv. Scarlet Nantes on 2,4-D- containing medium using well-established methods. Then the mixed cultures were transferred to, and serially subcultured on, a hormone-free medium near pH 4. The medium contained 1 mM NH4+ as the sole nitrogen source. When cultured in this way, embryonic globules were able to multiply without development into later embryo stages. Nonembryogenic callus did not survive. Continuous culture of embryonic globules on this low pH hormone-free medium yielded cultures consisting entirely of preglobular stage proembryos (PGSPs). PGSP cultures have been maintained as such with continuous multiplication for nearly 2 years without loss of embryogenic potential. These hormone-free-maintained PGSPs continue their development to later embryo stages when cultured on the same hormone-free medium buffered at pH 5.8. We show that hormone-free medium near pH 4 can replace 2,4-D in its ability to sustain multiplication of 2,4-D-initiated embryogenic cells of carrot at an acceptable growth rate without their development into later embryo stages. This procedure provides selective conditions that do not permit the growth of non-embryogenic cells while providing an adequate environment for embryogenic cell proliferation and should prove invaluable in studying habituation.

Impact of supplementary royal jelly on in vitro maturation of sheep oocytes: genes involved in apoptosis and embryonic development.

PubMed

Valiollahpoor Amiri, Mohammad; Deldar, Hamid; Ansari Pirsaraei, Zarbakht

2016-01-01

Optimizing culture conditions lead to the improvement of oocyte developmental competence and additives with anti-oxidative activity in culture media improved embryonic development. Royal jelly (RJ) is a product from the cephalic glands of nurse bees that has considerable health effects. The aim of this study was to investigate the effect of different concentrations of RJ on the maturation, cleavage, and blastocyst rates and gene expression in the oocyte and cumulus cells during in vitro maturation (IVM) of sheep oocyte. IVM of oocyte was performed in the presence of control (RJ0), 2.5 (RJ2.5), 5 (RJ5), 10 (RJ10), 20 (RJ20), and 40 (RJ40) mg/mL of RJ. Following the maturation period, parthenogenetic activation was carried out in two treatment groups (RJ0 and RJ10) and embryonic development was examined three and eight days thereafter. Moreover, the relative expression of BCL2 and BAX in oocyte as well as BCL2, BAX, HAS2, PTGS2, and STAR in cumulus cells were assessed. The results indicated that the addition of 10 mg/mL of RJ (90 ± 4.51%) to the maturation medium linearly increased the oocyte maturation rate compared to the control group (57 ± 2.42%), then it remained constant to the RJ40 (93 ± 3.10%) group. The higher RJ concentrations were associated with increased (p < 0.01) cleavage (53.3 ± 1.55% to 82.3 ± 2.82%) and blastocyst rate (15.5 ± 1.16% to 33.8 ± 3.09%) from the RJ0 to the RJ10 group. The relative mRNA expression of BCL2 and BAX in the oocyte was higher at RJ10. In cumulus cells, the expression of BCL2 was not affected, but that of BAX decreased, and expression of HAS2, PTGS2, and STAR were increased following the addition of RJ to the maturation media. In conclusion, the addition of 10 mg/mL of RJ to maturation medium improved blastocyst formation and decreased the apoptotic incidence in sheep cumulus cells and the oocyte during the in vitro development.

Altered embryonic development in northern bobwhite quail (Colinus virginianus) induced by pre-incubation oscillatory thermal stresses mimicking global warming predictions

PubMed Central

Reyna, Kelly S.

2017-01-01

Global warming is likely to alter reproductive success of ground-nesting birds that lay eggs normally left unattended for days or even weeks before actual parental incubation, especially in already warm climates. The native North American bobwhite quail (Colinus virginianus) is such a species, and pre-incubation quail eggs may experience temperatures ≥45°C. Yet, almost nothing is known about embryonic survival after such high pre-incubation temperatures. Freshly laid bobwhite quail eggs were exposed during a 12 day pre-incubation period to one of five thermal regimes: low oscillating temperatures (25–40°C, mean = 28.9°C), high oscillating temperatures (30–45°C, mean = 33.9°C), low constant temperatures (28.85°C), high constant temperatures (mean = 33.9°C), or commercially employed pre-incubation temperatures (20°C). After treatment, eggs were then incubated at a standard 37.5°C to determine subsequent effects on embryonic development rate, survival, water loss, hatching, and embryonic oxygen consumption. Both quantity of heating degree hours during pre-incubation and specific thermal regime (oscillating vs. non-oscillating) profoundly affected important aspects of embryo survival and indices of development and growth Pre-incubation quail eggs showed a remarkable tolerance to constant high temperatures (up to 45°C), surviving for 4.5±0.3 days of subsequent incubation, but high oscillating pre-incubation temperature increased embryo survival (mean survival 12.2±1.8 days) and led to more rapid development than high constant temperature (maximum 38.5°C), even though both groups experienced the same total heating degree-hours. Oxygen consumption was ~200–300 μl O2.egg.min-1 at hatching in all groups, and was not affected by pre-incubation conditions. Oscillating temperatures, which are the norm for pre-incubation quail eggs in their natural habitat, thus enhanced survival at higher temperatures. However, a 5°C increase in pre-incubation temperature, which equates to the predicted long-term increases of 5°C or more, nonetheless reduced hatching rate by approximately 50%. Thus, while pre-incubation bobwhite eggs may be resiliant to moderate oscillating temperature increases, global warming will likely severely impact wild bobwhite quail populations, especially in their strongholds in southern latitudes. PMID:28926597

Altered embryonic development in northern bobwhite quail (Colinus virginianus) induced by pre-incubation oscillatory thermal stresses mimicking global warming predictions.

PubMed

Reyna, Kelly S; Burggren, Warren W

2017-01-01

Global warming is likely to alter reproductive success of ground-nesting birds that lay eggs normally left unattended for days or even weeks before actual parental incubation, especially in already warm climates. The native North American bobwhite quail (Colinus virginianus) is such a species, and pre-incubation quail eggs may experience temperatures ≥45°C. Yet, almost nothing is known about embryonic survival after such high pre-incubation temperatures. Freshly laid bobwhite quail eggs were exposed during a 12 day pre-incubation period to one of five thermal regimes: low oscillating temperatures (25-40°C, mean = 28.9°C), high oscillating temperatures (30-45°C, mean = 33.9°C), low constant temperatures (28.85°C), high constant temperatures (mean = 33.9°C), or commercially employed pre-incubation temperatures (20°C). After treatment, eggs were then incubated at a standard 37.5°C to determine subsequent effects on embryonic development rate, survival, water loss, hatching, and embryonic oxygen consumption. Both quantity of heating degree hours during pre-incubation and specific thermal regime (oscillating vs. non-oscillating) profoundly affected important aspects of embryo survival and indices of development and growth Pre-incubation quail eggs showed a remarkable tolerance to constant high temperatures (up to 45°C), surviving for 4.5±0.3 days of subsequent incubation, but high oscillating pre-incubation temperature increased embryo survival (mean survival 12.2±1.8 days) and led to more rapid development than high constant temperature (maximum 38.5°C), even though both groups experienced the same total heating degree-hours. Oxygen consumption was ~200-300 μl O2.egg.min-1 at hatching in all groups, and was not affected by pre-incubation conditions. Oscillating temperatures, which are the norm for pre-incubation quail eggs in their natural habitat, thus enhanced survival at higher temperatures. However, a 5°C increase in pre-incubation temperature, which equates to the predicted long-term increases of 5°C or more, nonetheless reduced hatching rate by approximately 50%. Thus, while pre-incubation bobwhite eggs may be resiliant to moderate oscillating temperature increases, global warming will likely severely impact wild bobwhite quail populations, especially in their strongholds in southern latitudes.

Left-Right Asymmetry of Maturation Rates in Human Embryonic Neural Development.

PubMed

de Kovel, Carolien G F; Lisgo, Steven; Karlebach, Guy; Ju, Jia; Cheng, Gang; Fisher, Simon E; Francks, Clyde

2017-08-01

Left-right asymmetry is a fundamental organizing feature of the human brain, and neuropsychiatric disorders such as schizophrenia sometimes involve alterations of brain asymmetry. As early as 8 weeks postconception, the majority of human fetuses move their right arms more than their left arms, but because nerve fiber tracts are still descending from the forebrain at this stage, spinal-muscular asymmetries are likely to play an important developmental role. We used RNA sequencing to measure gene expression levels in the left and right spinal cords, and the left and right hindbrains, of 18 postmortem human embryos aged 4 to 8 weeks postconception. Genes showing embryonic lateralization were tested for an enrichment of signals in genome-wide association data for schizophrenia. The left side of the embryonic spinal cord was found to mature faster than the right side. Both sides transitioned from transcriptional profiles associated with cell division and proliferation at earlier stages to neuronal differentiation and function at later stages, but the two sides were not in synchrony (p = 2.2 E-161). The hindbrain showed a left-right mirrored pattern compared with the spinal cord, consistent with the well-known crossing over of function between these two structures. Genes that showed lateralization in the embryonic spinal cord were enriched for association signals with schizophrenia (p = 4.3 E-05). These are the earliest stage left-right differences of human neural development ever reported. Disruption of the lateralized developmental program may play a role in the genetic susceptibility to schizophrenia. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

The Maternal to Zygotic Transition in Mammals

PubMed Central

Li, Lei; Lu, Xukun; Dean, Jurrien

2013-01-01

Prior to activation of the embryonic genome, the initiating events of mammalian development are under maternal control and include fertilization, the block to polyspermy and processing sperm DNA. Following gamete union, the transcriptionally inert sperm DNA is repackaged into the male pronucleus which fuses with the female pronucleus to form a 1-cell zygote. Embryonic transcription begins during the maternal to zygotic transfer of control in directing development. This transition occurs at species-specific times after one or several rounds of blastomere cleavage and is essential for normal development. However, even after activation of the embryonic genome, successful development relies on stored maternal components without which embryos fail to progress beyond initial cell divisions. Better understanding of the molecular basis of maternal to zygotic transition including fertilization, the activation of the embryonic genome and cleavage-stage development will provide insight into early human development that should translate into clinical applications for regenerative medicine and assisted reproductive technologies. PMID:23352575

Intratumoral heterogeneity and chemoresistance in nonseminomatous germ cell tumor of the testis.

PubMed

Bilen, Mehmet Asim; Hess, Kenneth R; Campbell, Matthew T; Wang, Jennifer; Broaddus, Russell R; Karam, Jose A; Ward, John F; Wood, Christopher G; Choi, Seungtaek L; Rao, Priya; Zhang, Miao; Naing, Aung; General, Rosale; Cauley, Diana H; Lin, Sue-Hwa; Logothetis, Christopher J; Pisters, Louis L; Tu, Shi-Ming

2016-12-27

Nonseminomatous germ cell tumor of the testis (NSGCT) is largely curable. However, a small group of patients develop refractory disease. We investigated the hypothesis that intratumoral heterogeneity contributes to the emergence of chemoresistance and the development of refractory tumor subtypes. Our institution's records for January 2000 through December 2010 included 275 patients whose primary tumor showed pure embryonal carcinoma (pure E); mixed embryonal carcinoma, yolk sac tumor, and teratoma (EYT); or mixed embryonal carcinoma, yolk sac tumor, seminoma, and teratoma (EYST). Patients with EYST had the highest cancer-specific mortality rate (P = .001). They tended to undergo somatic transformation (P = .0007). Two of 5 patients with clinical stage I EYST who had developed recurrence during active surveillance died of their disease. In this retrospective study, we evaluated consecutive patients who had been diagnosed with the three most common histological phenotypes of NSGCT. Chemoresistance was defined as the presence of teratoma, viable germ cell tumor, or somatic transformation in the residual tumor or the development of progressive or relapsed disease after chemotherapy. In a separate prospective study, we performed next-generation sequencing on tumor samples from 39 patients to identify any actionable genetic mutations. Our data suggest that patients with EYST in their primary tumor may harbor a potentially refractory NSGCT phenotype and are at increased risk of dying from disease. Despite intratumoral heterogeneity, improved patient selection and personalized care of distinct tumor subtypes may optimize the clinical outcome of patients with NSGCT.

YB-1 Is Important for Late-Stage Embryonic Development, Optimal Cellular Stress Responses, and the Prevention of Premature Senescence

PubMed Central

Lu, Zhi Hong; Books, Jason T.; Ley, Timothy J.

2005-01-01

Proteins containing “cold shock” domains belong to the most evolutionarily conserved family of nucleic acid-binding proteins known among bacteria, plants, and animals. One of these proteins, YB-1, is widely expressed throughout development and has been implicated as a cell survival factor that regulates the transcription and/or translation of many cellular growth and death-related genes. For these reasons, YB-1 deficiency has been predicted to be incompatible with cell survival. However, the majority of YB-1−/− embryos develop normally up to embryonic day 13.5 (E13.5). After E13.5, YB-1−/− embryos exhibit severe growth retardation and progressive mortality, revealing a nonredundant role of YB-1 in late embryonic development. Fibroblasts derived from YB-1−/− embryos displayed a normal rate of protein synthesis and minimal alterations in the transcriptome and proteome but demonstrated reduced abilities to respond to oxidative, genotoxic, and oncogene-induced stresses. YB-1−/− cells under oxidative stress expressed high levels of the G1-specific CDK inhibitors p16Ink4a and p21Cip1 and senesced prematurely; this defect was corrected by knocking down CDK inhibitor levels with specific small interfering RNAs. These data suggest that YB-1 normally represses the transcription of CDK inhibitors, making it an important component of the cellular stress response signaling pathway. PMID:15899865

Regeneration of Solanum nigrum by somatic embryogenesis, involving frog egg-like body, a novel structure.

PubMed

Xu, Kedong; Chang, Yunxia; Liu, Kun; Wang, Feige; Liu, Zhongyuan; Zhang, Ting; Li, Tong; Zhang, Yi; Zhang, Fuli; Zhang, Ju; Wang, Yan; Niu, Wei; Jia, Shuzhao; Xie, Hengchang; Tan, Guangxuan; Li, Chengwei

2014-01-01

A new protocol was established for the regeneration of Solanum nigrum by frog egg-like bodies (FELBs), which are novel somatic embryogenesis (SE) structures induced from the root, stem, and leaf explants. The root, stem, and leaf explants (93.33%, 85.10%, and 100.00%, respectively) were induced to form special embryonic calli on Murashige and Skoog (MS) medium containing 1.0 mg/L 2,4-dichlorophenoxyacetic acid, under dark condition. Further, special embryonic calli from the root, stem, and leaf explants (86.97%, 83.30%, and 99.47%, respectively) were developed into FELBs. Plantlets of FELBs from the three explants were induced in vitro on MS medium supplemented with 5.0 mg/L 6-benzylaminopurine and 0.1 mg/L gibberellic acid, and 100.00% plantlet induction rates were noted. However, plantlet induction in vivo on MS medium supplemented with 20 mg/L thidiazuron showed rates of 38.63%, 15.63%, and 61.30% for the root, stem, and leaf explants, respectively, which were lower than those of the in vitro culture. Morphological and histological analyses of FELBs at different development stages revealed that they are a novel type of SE structure that developed from the mesophyll (leaf) or cortex (stem and root) cells of S. nigrum.

Application of response surface methodology to maximize the productivity of scalable automated human embryonic stem cell manufacture.

PubMed

Ratcliffe, Elizabeth; Hourd, Paul; Guijarro-Leach, Juan; Rayment, Erin; Williams, David J; Thomas, Robert J

2013-01-01

Commercial regenerative medicine will require large quantities of clinical-specification human cells. The cost and quality of manufacture is notoriously difficult to control due to highly complex processes with poorly defined tolerances. As a step to overcome this, we aimed to demonstrate the use of 'quality-by-design' tools to define the operating space for economic passage of a scalable human embryonic stem cell production method with minimal cell loss. Design of experiments response surface methodology was applied to generate empirical models to predict optimal operating conditions for a unit of manufacture of a previously developed automatable and scalable human embryonic stem cell production method. Two models were defined to predict cell yield and cell recovery rate postpassage, in terms of the predictor variables of media volume, cell seeding density, media exchange and length of passage. Predicted operating conditions for maximized productivity were successfully validated. Such 'quality-by-design' type approaches to process design and optimization will be essential to reduce the risk of product failure and patient harm, and to build regulatory confidence in cell therapy manufacturing processes.

An Alternative Method for Long-Term Culture of Chicken Embryonic Stem Cell In Vitro.

PubMed

Zhang, Li; Wu, Yenan; Li, Xiang; Wei, Shao; Xing, Yiming; Lian, Zhengxing; Han, Hongbing

2018-01-01

Chicken embryonic stem cells (cESCs) obtained from stage X embryos provide a novel model for the study of avian embryonic development. A new way to maintain cESCs for a long period in vitro still remains unexplored. We found that the cESCs showed stem cell-like properties in vitro for a long term with the support of DF-1 feeder and basic culture medium supplemented with human basic fibroblast growth factor (hbFGF), mouse stem cell factor (mSCF), and human leukemia inhibitory factor (hLIF). During the long culture period, the cESCs showed typical ES cell morphology and expressed primitive stem cell markers with a relatively stable proliferation rate and high telomerase activity. These cells also exhibited the capability to differentiate into cardiac myocytes, smooth muscle cells, neural cells, osteoblast, and adipocyte in vitro . Chimera chickens were produced by cESCs cultured for 25 passages with this new culture system. The experiments showed that DF-1 was the optimal feeder and hbFGF was an important factor for maintaining the pluripotency of cESCs in vitro .

ROCK inhibitor is not required for embryoid body formation from singularized human embryonic stem cells.

PubMed

Pettinato, Giuseppe; Vanden Berg-Foels, Wendy S; Zhang, Ning; Wen, Xuejun

2014-01-01

We report a technology to form human embryoid bodies (hEBs) from singularized human embryonic stem cells (hESCs) without the use of the p160 rho-associated coiled-coil kinase inhibitor (ROCKi) or centrifugation (spin). hEB formation was tested under four conditions: +ROCKi/+spin, +ROCKi/-spin, -ROCKi/+spin, and -ROCKi/-spin. Cell suspensions of BG01V/hOG and H9 hESC lines were pipetted into non-adherent hydrogel substrates containing defined microwell arrays. hEBs of consistent size and spherical geometry can be formed in each of the four conditions, including the -ROCKi/-spin condition. The hEBs formed under the -ROCKi/-spin condition differentiated to develop the three embryonic germ layers and tissues derived from each of the germ layers. This simplified hEB production technique offers homogeneity in hEB size and shape to support synchronous differentiation, elimination of the ROCKi xeno-factor and rate-limiting centrifugation treatment, and low-cost scalability, which will directly support automated, large-scale production of hEBs and hESC-derived cells needed for clinical, research, or therapeutic applications.

Regulation of embryonic neurotransmitter and tyrosine hydroxylase protein levels by ascorbic acid

PubMed Central

Meredith, M. Elizabeth; May, James M.

2013-01-01

Scope: Ascorbic acid (ascorbate) is required to recycle tetrahydrobiopterin, which is necessary for neurotransmitter synthesis by the rate-limiting enzymes tyrosine and tryptophan hydroxylases. We sought to determine whether ascorbate might regulate embryonic brain cortex monoamine synthesis utilizing transgenic mouse models with varying intracellular ascorbate levels. Methods and Results: In embryos lacking the sodium-dependent vitamin C transporter 2 (SVCT2), very low levels of brain ascorbate decreased cortex levels of norepinephrine and dopamine by approximately 33%, but had no effect on cortex serotonin or its metabolite, 5-hydroxyindole acetic acid. This decrease in ascorbate also led to a decrease in protein levels of tyrosine hydroxylase, but not of tryptophan hydroxylase. Increased cortex ascorbate in embryos carrying extra copies of the SVCT2 resulted in increased levels of dopamine and its metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), as well as serotonin and 5-hydroxyindole acetic acid. Conclusion: The dependence of embryonic brain cortex neurotransmitter synthesis and tyrosine hydroxylase expression on intracellular ascorbate emphasizes the importance of receiving adequate ascorbate during development. PMID:24095796

Vitamin D receptor signaling is required for heart development in zebrafish embryo

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

Kwon, Hye-Joo, E-mail: hjkwon@pnu.edu.sa; Biology Department, Princess Nourah University, Riyadh 11671

Vitamin D has been found to be associated with cardiovascular diseases. However, the role of vitamin D in heart development during embryonic period is largely unknown. Vitamin D induces its genomic effects through its nuclear receptor, the vitamin D receptor (VDR). The present study investigated the role of VDR on heart development by antisense-mediated knockdown approaches in zebrafish model system. In zebrafish embryos, two distinct VDR genes (vdra and vdrb) have been identified. Knockdown of vdra has little effect on heart development, whereas disrupting vdrb gene causes various cardiac phenotypes, characterized by pericardial edema, slower heart rate and laterality defects.more » Depletion of both vdra and vdrb (vdra/b) produce additive, but not synergistic effects. To determine whether atrioventricular (AV) cardiomyocytes are properly organized in these embryos, the expression of bmp4, which marks the developing AV boundary at 48 h post-fertilization, was examined. Notably, vdra/b-deficient embryos display ectopic expression of bmp4 towards the ventricle or throughout atrial and ventricular chambers. Taken together, these results suggest that VDR signaling plays an essential role in heart development. - Highlights: • VDR signaling is involved in embryonic heart development. • Knockdown of vdrb, but not vdra, causes decreased heart rate in zebrafish embryo. • Loss of vdr results in cardiac laterality defects. • Loss of vdra/b alters atrioventricular boundary formation. • Loss of vdra/b causes abnormal cardiac looping.« less

Embryos of a moss can be hardened to desiccation tolerance: effects of rate of drying on the timeline of recovery and dehardening in Aloina ambigua (Pottiaceae).

PubMed

Brinda, John C; Stark, Lloyd R; Clark, Theresa A; Greenwood, Joshua L

2016-01-01

Embryonic sporophytes of the moss Aloina ambigua are inducibly desiccation tolerant (DT). Hardening to DT describes a condition of temporary tolerance to a rapid-drying event conferred by a previous slow-drying event. This paper aimed to determine whether sporophytic embryos of a moss can be hardened to DT, to assess how the rate of desiccation influences the post-rehydration dynamics of recovery, hardening and dehardening, and to determine the minimum rate of drying for embryos and shoots. Embryos were exposed to a range of drying rates using wetted filter paper in enclosed Petri dishes, monitoring relative humidity (RH) inside the dish and equilibrating tissues with 50% RH. Rehydrated embryos and shoots were subjected to a rapid-drying event at intervals, allowing assessments of recovery, hardening and dehardening times. The minimum rate of slow drying for embryonic survival was ∼3·5 h and for shoots ∼9 h. Hardening to DT was dependent upon the prior rate of drying. When the rate of drying was extended to 22 h, embryonic hardening was strong (>50% survival) with survival directly proportional to the post-rehydration interval preceding rapid drying. The recovery time (repair/reassembly) was so short as to be undetectable in embryos and shoots desiccated gradually; however, embryos dried in <3·5 h exhibited a lag time in development of ∼4 d, consistent with recovery. Dehardening resulted in embryos incapable of surviving a rapid-drying event. The ability of moss embryos to harden to DT and the influence of prior rate of drying on the dynamics of hardening are shown for the first time. The minimum rate of drying is introduced as a new metric for assessing ecological DT, defined as the minimum duration at sub-turgor during a drying event in which upon rehydration the plant organ of interest survives relatively undamaged from the desiccating event. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Embryos of a moss can be hardened to desiccation tolerance: effects of rate of drying on the timeline of recovery and dehardening in Aloina ambigua (Pottiaceae)

PubMed Central

Brinda, John C.; Stark, Lloyd R.; Clark, Theresa A.; Greenwood, Joshua L.

2016-01-01

Background and Aims Embryonic sporophytes of the moss Aloina ambigua are inducibly desiccation tolerant (DT). Hardening to DT describes a condition of temporary tolerance to a rapid-drying event conferred by a previous slow-drying event. This paper aimed to determine whether sporophytic embryos of a moss can be hardened to DT, to assess how the rate of desiccation influences the post-rehydration dynamics of recovery, hardening and dehardening, and to determine the minimum rate of drying for embryos and shoots. Methods Embryos were exposed to a range of drying rates using wetted filter paper in enclosed Petri dishes, monitoring relative humidity (RH) inside the dish and equilibrating tissues with 50 % RH. Rehydrated embryos and shoots were subjected to a rapid-drying event at intervals, allowing assessments of recovery, hardening and dehardening times. Key Results The minimum rate of slow drying for embryonic survival was ∼3·5 h and for shoots ∼9 h. Hardening to DT was dependent upon the prior rate of drying. When the rate of drying was extended to 22 h, embryonic hardening was strong (>50 % survival) with survival directly proportional to the post-rehydration interval preceding rapid drying. The recovery time (repair/reassembly) was so short as to be undetectable in embryos and shoots desiccated gradually; however, embryos dried in <3·5 h exhibited a lag time in development of ∼4 d, consistent with recovery. Dehardening resulted in embryos incapable of surviving a rapid-drying event. Conclusions The ability of moss embryos to harden to DT and the influence of prior rate of drying on the dynamics of hardening are shown for the first time. The minimum rate of drying is introduced as a new metric for assessing ecological DT, defined as the minimum duration at sub-turgor during a drying event in which upon rehydration the plant organ of interest survives relatively undamaged from the desiccating event. PMID:26354931

Dynamic and static maintenance of epigenetic memory in pluripotent and somatic cells.

PubMed

Shipony, Zohar; Mukamel, Zohar; Cohen, Netta Mendelson; Landan, Gilad; Chomsky, Elad; Zeliger, Shlomit Reich; Fried, Yael Chagit; Ainbinder, Elena; Friedman, Nir; Tanay, Amos

2014-09-04

Stable maintenance of gene regulatory programs is essential for normal function in multicellular organisms. Epigenetic mechanisms, and DNA methylation in particular, are hypothesized to facilitate such maintenance by creating cellular memory that can be written during embryonic development and then guide cell-type-specific gene expression. Here we develop new methods for quantitative inference of DNA methylation turnover rates, and show that human embryonic stem cells preserve their epigenetic state by balancing antagonistic processes that add and remove methylation marks rather than by copying epigenetic information from mother to daughter cells. In contrast, somatic cells transmit considerable epigenetic information to progenies. Paradoxically, the persistence of the somatic epigenome makes it more vulnerable to noise, since random epimutations can accumulate to massively perturb the epigenomic ground state. The rate of epigenetic perturbation depends on the genomic context, and, in particular, DNA methylation loss is coupled to late DNA replication dynamics. Epigenetic perturbation is not observed in the pluripotent state, because the rapid turnover-based equilibrium continuously reinforces the canonical state. This dynamic epigenetic equilibrium also explains how the epigenome can be reprogrammed quickly and to near perfection after induced pluripotency.

A Novel Approach for Studying the Temporal Modulation of Embryonic Skeletal Development Using Organotypic Bone Cultures and Microcomputed Tomography

PubMed Central

Smith, Emma L.; Roberts, Carol A.

2012-01-01

Understanding the structural development of embryonic bone in a three dimensional framework is fundamental to developing new strategies for the recapitulation of bone tissue in latter life. We present an innovative combined approach of an organotypic embryonic femur culture model, microcomputed tomography (μCT) and immunohistochemistry to examine the development and modulation of the three dimensional structures of the developing embryonic femur. Isolated embryonic chick femurs were organotypic (air/liquid interface) cultured for 10 days in either basal, chondrogenic, or osteogenic supplemented culture conditions. The growth development and modulating effects of basal, chondrogenic, or osteogenic culture media of the embryonic chick femurs was investigated using μCT, immunohistochemistry, and histology. The growth and development of noncultured embryonic chick femur stages E10, E11, E12, E13, E15, and E17 were very closely correlated with increased morphometric indices of bone formation as determined by μCT. After 10 days in the organotpyic culture set up, the early aged femurs (E10 and E11) demonstrated a dramatic response to the chondrogenic or osteogenic culture conditions compared to the basal cultured femurs as determined by a change in μCT morphometric indices and modified expression of chondrogenic and osteogenic markers. Although the later aged femurs (E12 and E13) increased in size and structure after 10 days organotpypic culture, the effects of the osteogenic and chondrogenic organotypic cultures on these femurs were not significantly altered compared to basal conditions. We have demonstrated that the embryonic chick femur organotpyic culture model combined with the μCT and immunohistochemical analysis can provide an integral methodology for investigating the modulation of bone development in an ex vivo culture setting. Hence, these interdisciplinary techniques of μCT and whole organ bone cultures will enable us to delineate some of the temporal, structural developmental paradigms and modulation of bone tissue formation to underpin innovative skeletal regenerative technology for clinical therapeutic strategies in musculoskeletal trauma and diseases. PMID:22472170

Development and maintenance of a telescoping debris flow fan in response to human-induced fan surface channelization, Chalk Creek Valley Natural Debris Flow Laboratory, Colorado, USA

NASA Astrophysics Data System (ADS)

Wasklewicz, T.; Scheinert, C.

2016-01-01

Channel change has been a constant theme throughout William L. Graf's research career. Graf's work has examined channel changes in the context of natural environmental fluctuations, but more often has focused on quantifying channel change in the context of anthropogenic modifications. Here, we consider how channelization of a debris flows along a bajada has perpetuated and sustained the development of 'telescoping' alluvial fan. Two-dimensional debris-flow modeling shows the importance of the deeply entrenched channelized flow in the development of a telescoping alluvial fan. GIS analyses of repeat (five different debris flows), high-resolution (5 cm) digital elevation models (DEMs) generated from repeat terrestrial laser scanning (TLS) data elucidate sediment and topographic dynamics of the new telescoping portion of the alluvial fan (the embryonic fan). Flow constriction from channelization helps to perpetuate debris-flow runout and to maintain the embryonic fan and telescoping nature of the alluvial fan complex. Embryonic fan development, in response to five debris flows, proceeds with a major portion of the flows depositing on the southern portion of the embryonic fan. The third through the fifth debris flows also begin to shift some deposition to the northern portion of the embryonic. The transfer of sediment from a higher portion of the embryonic fan to a lower portion continues currently on the embryonic fan. While channelized flow has been shown to be critical to the maintenance of the telescoping fan, the flow constriction has led to higher than background levels of sediment deposition in Chalk Creek, a tributary of the Arkansas River. A majority of the sediment from each debris flow is incorporated into Chalk Creek as opposed to being stored on the embryonic fan.

Effect of antioxidant of bamboo leaves on gene expression associated with mouse embryonic fibroblast reproduction and embryonic development.

PubMed

Yu, Feng; Qian, Xiaowei; Zeng, Zhanghui; Zhao, Xiaoli; Hou, Rong; Zhang, Zhihe; Bian, Hongwu; Han, Ning; Wang, Junhui; Zhu, Muyuan

2017-11-01

Antioxidant of bamboo leaves (AOB) was certified to be a natural antioxidant by the Chinese Ministry of Health in 2003. However, the effects of AOB on animal reproductive and developmental functions remain unclear. The present study aimed to investigate the effects of different concentrations of AOB on mouse embryonic fibroblast (MEF) cells, and to examine the underlying molecular mechanism through which AOB affects the proliferation and apoptosis of MEFs. MEFs prepared from individual embryos were treated with various dosages of AOB. Cell viability and apoptosis were detected by MTT and flow cytometry assays, respectively. Reverse transcription‑quantitative polymerase chain reaction and western blot analyses were used for the detection of mRNA and protein expression. Functional annotation of differentially‑expressed genes was performed according to the Gene Ontology database and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Compared with the control group, ~50% of MEF cells were inhibited following treatment with a 400 µg/ml concentration of AOB. Treatment with 400 µg/ml AOB for 72 h significantly increased the apoptotic rate of MEF cells compared with the control group. Following treatment with AOB, dehydrogenase/reductase 9, phospholipase A2 group IVE and platelet derived growth factor B were downregulated, while 17 other genes were upregulated in MEF cells. Treatment with AOB markedly increased the expression of phosphorylated extracellular signal‑regulated kinase (ERK), β‑catenin, transcription factor SOX‑17, calcium‑binding tyrosine phosphorylation‑regulated protein, and cholesterol side chain cleavage enzyme mitochondrial (P<0.01). Additionally, the ERK pathway inhibitor U0126 and Wnt pathway inhibitor dickkopf‑related protein 1 markedly suppressed the expression of the above genes (P<0.01). AOB may impact the expression of proteins associated with embryonic fibroblast reproduction and embryonic development through activation of the ERK and Wnt signaling pathways, thus influencing cellular processes.

Transcriptional profiles of bovine in vivo pre-implantation development.

PubMed

Jiang, Zongliang; Sun, Jiangwen; Dong, Hong; Luo, Oscar; Zheng, Xinbao; Obergfell, Craig; Tang, Yong; Bi, Jinbo; O'Neill, Rachel; Ruan, Yijun; Chen, Jingbo; Tian, Xiuchun Cindy

2014-09-04

During mammalian pre-implantation embryonic development dramatic and orchestrated changes occur in gene transcription. The identification of the complete changes has not been possible until the development of the Next Generation Sequencing Technology. Here we report comprehensive transcriptome dynamics of single matured bovine oocytes and pre-implantation embryos developed in vivo. Surprisingly, more than half of the estimated 22,000 bovine genes, 11,488 to 12,729 involved in more than 100 pathways, is expressed in oocytes and early embryos. Despite the similarity in the total numbers of genes expressed across stages, the nature of the expressed genes is dramatically different. A total of 2,845 genes were differentially expressed among different stages, of which the largest change was observed between the 4- and 8-cell stages, demonstrating that the bovine embryonic genome is activated at this transition. Additionally, 774 genes were identified as only expressed/highly enriched in particular stages of development, suggesting their stage-specific roles in embryogenesis. Using weighted gene co-expression network analysis, we found 12 stage-specific modules of co-expressed genes that can be used to represent the corresponding stage of development. Furthermore, we identified conserved key members (or hub genes) of the bovine expressed gene networks. Their vast association with other embryonic genes suggests that they may have important regulatory roles in embryo development; yet, the majority of the hub genes are relatively unknown/under-studied in embryos. We also conducted the first comparison of embryonic expression profiles across three mammalian species, human, mouse and bovine, for which RNA-seq data are available. We found that the three species share more maternally deposited genes than embryonic genome activated genes. More importantly, there are more similarities in embryonic transcriptomes between bovine and humans than between humans and mice, demonstrating that bovine embryos are better models for human embryonic development. This study provides a comprehensive examination of gene activities in bovine embryos and identified little-known potential master regulators of pre-implantation development.

Identification and Characterization of Long Non-Coding RNAs Related to Mouse Embryonic Brain Development from Available Transcriptomic Data

PubMed Central

He, Hongjuan; Xiu, Youcheng; Guo, Jing; Liu, Hui; Liu, Qi; Zeng, Tiebo; Chen, Yan; Zhang, Yan; Wu, Qiong

2013-01-01

Long non-coding RNAs (lncRNAs) as a key group of non-coding RNAs have gained widely attention. Though lncRNAs have been functionally annotated and systematic explored in higher mammals, few are under systematical identification and annotation. Owing to the expression specificity, known lncRNAs expressed in embryonic brain tissues remain still limited. Considering a large number of lncRNAs are only transcribed in brain tissues, studies of lncRNAs in developmental brain are therefore of special interest. Here, publicly available RNA-sequencing (RNA-seq) data in embryonic brain are integrated to identify thousands of embryonic brain lncRNAs by a customized pipeline. A significant proportion of novel transcripts have not been annotated by available genomic resources. The putative embryonic brain lncRNAs are shorter in length, less spliced and show less conservation than known genes. The expression of putative lncRNAs is in one tenth on average of known coding genes, while comparable with known lncRNAs. From chromatin data, putative embryonic brain lncRNAs are associated with active chromatin marks, comparable with known lncRNAs. Embryonic brain expressed lncRNAs are also indicated to have expression though not evident in adult brain. Gene Ontology analysis of putative embryonic brain lncRNAs suggests that they are associated with brain development. The putative lncRNAs are shown to be related to possible cis-regulatory roles in imprinting even themselves are deemed to be imprinted lncRNAs. Re-analysis of one knockdown data suggests that four regulators are associated with lncRNAs. Taken together, the identification and systematic analysis of putative lncRNAs would provide novel insights into uncharacterized mouse non-coding regions and the relationships with mammalian embryonic brain development. PMID:23967161

The ‘Ventral Organs’ of Pycnogonida (Arthropoda) Are Neurogenic Niches of Late Embryonic and Post-Embryonic Nervous System Development

PubMed Central

Brenneis, Georg; Scholtz, Gerhard

2014-01-01

Early neurogenesis in arthropods has been in the focus of numerous studies, its cellular basis, spatio-temporal dynamics and underlying genetic network being by now comparably well characterized for representatives of chelicerates, myriapods, hexapods and crustaceans. By contrast, neurogenesis during late embryonic and/or post-embryonic development has received less attention, especially in myriapods and chelicerates. Here, we apply (i) immunolabeling, (ii) histology and (iii) scanning electron microscopy to study post-embryonic ventral nerve cord development in Pseudopallene sp., a representative of the sea spiders (Pycnogonida), the presumable sister group of the remaining chelicerates. During early post-embryonic development, large neural stem cells give rise to additional ganglion cell material in segmentally paired invaginations in the ventral ectoderm. These ectodermal cell regions – traditionally designated as ‘ventral organs’ – detach from the surface into the interior and persist as apical cell clusters on the ventral ganglion side. Each cluster is a post-embryonic neurogenic niche that features a tiny central cavity and initially still houses larger neural stem cells. The cluster stays connected to the underlying ganglionic somata cortex via an anterior and a posterior cell stream. Cell proliferation remains restricted to the cluster and streams, and migration of newly produced cells along the streams seems to account for increasing ganglion cell numbers in the cortex. The pycnogonid cluster-stream-systems show striking similarities to the life-long neurogenic system of decapod crustaceans, and due to their close vicinity to glomerulus-like neuropils, we consider their possible involvement in post-embryonic (perhaps even adult) replenishment of olfactory neurons – as in decapods. An instance of a potentially similar post-embryonic/adult neurogenic system in the arthropod outgroup Onychophora is discussed. Additionally, we document two transient posterior ganglia in the ventral nerve cord of Pseudopallene sp. and evaluate this finding in light of the often discussed reduction of a segmented ‘opisthosoma’ during pycnogonid evolution. PMID:24736377

Virtual reality imaging techniques in the study of embryonic and early placental health.

PubMed

Rousian, Melek; Koster, Maria P H; Mulders, Annemarie G M G J; Koning, Anton H J; Steegers-Theunissen, Régine P M; Steegers, Eric A P

2018-04-01

Embryonic and placental growth and development in the first trimester of pregnancy have impact on the health of the fetus, newborn, child and even the adult. This emphasizes the importance of this often neglected period in life. The development of three-dimensional transvaginal ultrasonography in combination with virtual reality (VR) opens the possibility of accurate and reliable visualization of embryonic and placental structures with real depth perception. These techniques enable new biometry and volumetry measurements that contribute to the knowledge of the (patho)physiology of embryonic and early placental health. Examples of such measurements are the length of complex structures like the umbilical cord, vitelline duct, limbs and cerebellum or the volume of the whole embryo and brain cavities. Moreover, for the first time, embryos can now be staged in vivo (Carnegie stages) and vasculature volumes of both the embryo and the early placenta can be measured when VR is combined with power Doppler signals. These innovative developments have already been used to study associations between periconceptional maternal factors, such as age, smoking, alcohol use, diet and vitamin status, and embryonic and early placental growth and development. Future studies will also focus on the identification of abnormal embryonic and early placental development already in the earliest weeks of pregnancy, which provides opportunities for early prevention of pregnancy complications. Copyright © 2018 IFPA, Elsevier Ltd. Published by Elsevier Ltd.. All rights reserved.

Developmental capacity of Ascaridia galli eggs is preserved after anaerobic storage in faeces.

PubMed

Tarbiat, B; Rahimian, S; Jansson, D S; Halvarsson, P; Höglund, J

2018-05-15

The reliability of the results of in vitro studies such as detection of anthelmintic resistance often depends on the ability of the parasite eggs to develop under laboratory conditions. The aim of this study was to assess the embryonation capability of the chicken roundworm Ascaridia galli eggs after storage under different conditions. Two storage media for parasite eggs were used; faeces or water. Eggs in petri dishes (90 dishes in total) containing faces or water media were first exposed either to aerobic or anaerobic conditions at different temperatures (4 °C /+O 2 , 4 °C /-O 2 , 25 °C/-O 2 ) for a maximum of 72 days. Every second week, materials from petri dishes in triplicates were recovered and incubated aerobically for two weeks at 25 °C. After the incubation, 200-300 eggs from each petri shish (sampling unit) were counted and the number of embryonated eggs was determined. Data was analyzed in R (version 3.4.3) A logistic regression model with the probability of an egg to embryonate as dependent variable and conditions, storage medium and time points as fixed effects with quasibinomial distribution was run. Least-square means were calculated and pairwise comparisons were made with the fixed effect factors (condition, storage medium and time point). Eggs in faeces had a significantly (p ˂ 0.05) higher embryonation than those in water, irrespective of storage conditions. At 4 °C embryonation tended to decline over time under aerobic conditions irrespective of the storage medium, whereas it remained constant following storage at anaerobic conditions. In contrast, anaerobic storage at the 25 °C negatively affected egg development in both media, except for day 14 in faeces. Our major finding was that eggs in faeces under anaerobic conditions and at 4 °C retained the highest rate of development, with a minimum decline in their developmental capacity over time compared to cleaned eggs stored in water. Copyright © 2018 Elsevier B.V. All rights reserved.

Dietary genistein supplementation in laying broiler breeder hens alters the development and metabolism of offspring embryos as revealed by hepatic transcriptome analysis.

PubMed

Lv, Zengpeng; Fan, Hao; Zhang, Beibei; Ning, Chao; Xing, Kun; Guo, Yuming

2018-03-08

Genistein (GEN) is a type of isoflavone mainly derived from soy products. In this experiment, we added 40 and 400 mg/kg GEN to the diet of laying broiler breeder hens to clarify the maternal effects of GEN on the development and metabolism of chick embryos. GEN treatment at 40 mg/kg increased embryonic length, weight, and liver index, as well as the width of the proliferative zone in the tibial growth plate of chick embryos. Gene ontology (GO) cluster analysis of the hepatic transcriptome showed that GEN treatment promoted embryonic development and cell proliferation. Low-dose GEN treatment increased insulin growth factor-binding protein (IGFBP)3 mRNA expression in the embryonic liver, whereas high-dose GEN treatment increased IGFBP5 expression and activated the apoptosis and protein tyrosine kinase signaling pathways. Furthermore, adding supplemental GEN to the diet of hens promoted the glycolysis process in the embryonic liver through the insulin-signaling pathway, upregulated target genes (phosphoglucomutase-2, hexokinase 1, dihydroxyacetone phosphate by aldolase, phosphofructokinase, platelet, and enolase 2), and enhanced the transport of carboxylic acids and cholesterol and the synthesis of unsaturated fatty acid (arachidonic acid) in the embryonic liver through upregulation of liver X receptor, sterol regulatory element-binding protein 1, and patatin-like phospholipase A. Additionally, GEN treatment increased fatty acid β-oxidation and Na + /K + -ATPase activity in the embryonic liver through activation of peroxisome proliferator-activated receptors (PPARs; PPARα and PPARδ) and the AMPK signaling pathway, which could provide energy for embryonic development. In addition, GEN treatment in hens increased superoxide dismutase activity and metallothionein expression in the chick embryonic liver and promoted lymphocyte proliferation through upregulation of mRNA expression of CDKN1A, IL12RB1, Sox11, PRKAR1A, PRKCQ, and TCF3. The improved immunity and antioxidant capacity, as a result of maternal GEN effects, was conducive to embryonic development. In conclusion, the addition of GEN to the diet of laying broiler breeder hens significantly promoted the development and metabolism of chick embryos.-Lv, Z., Fan, H., Zhang, B., Ning, C., Xing, K., Guo, Y. Dietary genistein supplementation in laying broiler breeder hens alters the development and metabolism of offspring embryos as revealed by hepatic transcriptome analysis.

Embryonic Cerebrospinal Fluid Increases Neurogenic Activity in the Brain Ventricular-Subventricular Zone of Adult Mice.

PubMed

Alonso, Maria I; Lamus, Francisco; Carnicero, Estela; Moro, Jose A; de la Mano, Anibal; Fernández, Jose M F; Desmond, Mary E; Gato, Angel

2017-01-01

Neurogenesis is a very intensive process during early embryonic brain development, becoming dramatically restricted in the adult brain in terms of extension and intensity. We have previously demonstrated the key role of embryonic cerebrospinal fluid (CSF) in developing brain neurogenic activity. We also showed that cultured adult brain neural stem cells (NSCs) remain competent when responding to the neurogenic influence of embryonic CSF. However, adult CSF loses its neurogenic inductive properties. Here, by means of an organotypic culture of adult mouse brain sections, we show that local administration of embryonic CSF in the subventricular zone (SVZ) niche is able to trigger a neurogenic program in NSCs. This leads to a significant increase in the number of non-differentiated NSCs, and also in the number of new neurons which show normal migration, differentiation and maturation. These new data reveal that embryonic CSF activates adult brain NSCs, supporting the previous idea that it contains key instructive components which could be useful in adult brain neuroregenerative strategies.

Embryonic Cerebrospinal Fluid Increases Neurogenic Activity in the Brain Ventricular-Subventricular Zone of Adult Mice

PubMed Central

Alonso, Maria I.; Lamus, Francisco; Carnicero, Estela; Moro, Jose A.; de la Mano, Anibal; Fernández, Jose M. F.; Desmond, Mary E.; Gato, Angel

2017-01-01

Neurogenesis is a very intensive process during early embryonic brain development, becoming dramatically restricted in the adult brain in terms of extension and intensity. We have previously demonstrated the key role of embryonic cerebrospinal fluid (CSF) in developing brain neurogenic activity. We also showed that cultured adult brain neural stem cells (NSCs) remain competent when responding to the neurogenic influence of embryonic CSF. However, adult CSF loses its neurogenic inductive properties. Here, by means of an organotypic culture of adult mouse brain sections, we show that local administration of embryonic CSF in the subventricular zone (SVZ) niche is able to trigger a neurogenic program in NSCs. This leads to a significant increase in the number of non-differentiated NSCs, and also in the number of new neurons which show normal migration, differentiation and maturation. These new data reveal that embryonic CSF activates adult brain NSCs, supporting the previous idea that it contains key instructive components which could be useful in adult brain neuroregenerative strategies. PMID:29311854

Microfluidic-based patterning of embryonic stem cells for in vitro development studies.

PubMed

Suri, Shalu; Singh, Ankur; Nguyen, Anh H; Bratt-Leal, Andres M; McDevitt, Todd C; Lu, Hang

2013-12-07

In vitro recapitulation of mammalian embryogenesis and examination of the emerging behaviours of embryonic structures require both the means to engineer complexity and accurately assess phenotypes of multicellular aggregates. Current approaches to study multicellular populations in 3D configurations are limited by the inability to create complex (i.e. spatially heterogeneous) environments in a reproducible manner with high fidelity thus impeding the ability to engineer microenvironments and combinations of cells with similar complexity to that found during morphogenic processes such as development, remodelling and wound healing. Here, we develop a multicellular embryoid body (EB) fusion technique as a higher-throughput in vitro tool, compared to a manual assembly, to generate developmentally relevant embryonic patterns. We describe the physical principles of the EB fusion microfluidic device design; we demonstrate that >60 conjoined EBs can be generated overnight and emulate a development process analogous to mouse gastrulation during early embryogenesis. Using temporal delivery of bone morphogenic protein 4 (BMP4) to embryoid bodies, we recapitulate embryonic day 6.5 (E6.5) during mouse embryo development with induced mesoderm differentiation in murine embryonic stem cells leading to expression of Brachyury-T-green fluorescent protein (T-GFP), an indicator of primitive streak development and mesoderm differentiation during gastrulation. The proposed microfluidic approach could be used to manipulate hundreds or more of individual embryonic cell aggregates in a rapid fashion, thereby allowing controlled differentiation patterns in fused multicellular assemblies to generate complex yet spatially controlled microenvironments.

Microfluidic-based patterning of embryonic stem cells for in vitro development studies

PubMed Central

Suri, Shalu; Singh, Ankur; Nguyen, Anh H.; Bratt-Leal, Andres M.; McDevitt, Todd C.

2013-01-01

In vitro recapitulation of mammalian embryogenesis and examination of the emerging behaviours of embryonic structures require both the means to engineer complexity and accurately assess phenotypes of multicellular aggregates. Current approaches to study multicellular populations in 3D configurations are limited by the inability to create complex (i.e. spatially heterogeneous) environments in a reproducible manner with high fidelity thus impeding the ability to engineer microenvironments and combinations of cells with similar complexity to that found during morphogenic processes such as development, remodelling and wound healing. Here, we develop a multicellular embryoid body (EB) fusion technique as a higher-throughput in vitro tool, compared to a manual assembly, to generate developmentally relevant embryonic patterns. We describe the physical principles of the EB fusion microfluidic device design; we demonstrate that >60 conjoined EBs can be generated overnight and emulate a development process analogous to mouse gastrulation during early embryogenesis. Using temporal delivery of bone morphogenic protein 4 (BMP4) to embryoid bodies, we recapitulate embryonic day 6.5 (E6.5) during mouse embryo development with induced mesoderm differentiation in murine embryonic stem cells leading to expression of Brachyury-T-green fluorescent protein (T-GFP), an indicator of primitive streak development and mesoderm differentiation during gastrulation. The proposed microfluidic approach could be used to manipulate hundreds or more of individual embryonic cell aggregates in a rapid fashion, thereby allowing controlled differentiation patterns in fused multicellular assemblies to generate complex yet spatially controlled microenvironments. PMID:24113509

Influence of sire and sire breed (Gyr versus Holstein) on establishment of pregnancy and embryonic loss in lactating Holstein cows during summer heat stress.

PubMed

Pegorer, Marcelo F; Vasconcelos, José L M; Trinca, Luzia A; Hansen, Peter J; Barros, Ciro M

2007-03-01

Heat stress has negative effects on pregnancy rates of lactating dairy cattle. There are genetic differences in tolerance to heat stress; Bos taurus indicus (B. t. indicus) cattle and embryos are more thermotolerant than Bos taurus taurus (B. t. taurus). In the present study, the effects of sire and sire breed on conception and embryonic/fetal loss rates of lactating Holstein cows during the Brazilian summer were determined. In Experiment 1, cows (n=302) were AI after estrus detection or at a fixed-time with semen from one Gyr (B. t. indicus) or one Holstein sire (B. t. taurus). Pregnancy was diagnosed 80 days after AI. In Experiment 2, cows (n=811) were AI with semen from three Gyr and two Holstein sires. Pregnancy was diagnosed at 30-40 and at 60-80 days after AI. Cows diagnosed pregnant at the first examination but non-pregnant at the second were considered as having lost their embryo or fetus. Data were analyzed by logistic regression. The model considered the effect of sire within breed, sire breed, days postpartum, period of lactation, and AI type (AI after estrus versus fixed-time). There was no effect of the AI type, days postpartum or milk production on conception or embryonic loss rates. The use of Gyr bulls increased pregnancy rate when compared to Holstein bulls [9.1% (60/657) versus 5.0% (23/456), respectively, P=0.008; data from Experiments 1 and 2 combined]. Additionally, in Experiment 2, cows inseminated using semen from sire #4 (Gyr) had lower embryonic loss (10%) when compared with other B. t. indicus (35.3% and 40%) or B. t. taurus sires (18.2% and 38.5%, P=0.03). In conclusion, the use of B. t. indicus sires may result in higher conception rates in lactating Holstein cows during summer heat stress. Moreover, sire can affect embryonic loss and selection of bulls according to this criterion may result in higher parturition rates in lactating Holstein cows.

Nuclear receptor TLX regulates cell cycle progression in neural stem cells of the developing brain.

PubMed

Li, Wenwu; Sun, Guoqiang; Yang, Su; Qu, Qiuhao; Nakashima, Kinichi; Shi, Yanhong

2008-01-01

TLX is an orphan nuclear receptor that is expressed exclusively in vertebrate forebrains. Although TLX is known to be expressed in embryonic brains, the mechanism by which it influences neural development remains largely unknown. We show here that TLX is expressed specifically in periventricular neural stem cells in embryonic brains. Significant thinning of neocortex was observed in embryonic d 14.5 TLX-null brains with reduced nestin labeling and decreased cell proliferation in the germinal zone. Cell cycle analysis revealed both prolonged cell cycles and increased cell cycle exit in TLX-null embryonic brains. Increased expression of a cyclin-dependent kinase inhibitor p21 and decreased expression of cyclin D1 provide a molecular basis for the deficiency of cell cycle progression in embryonic brains of TLX-null mice. Furthermore, transient knockdown of TLX by in utero electroporation led to precocious cell cycle exit and differentiation of neural stem cells followed by outward migration. Together these results indicate that TLX plays an important role in neural development by regulating cell cycle progression and exit of neural stem cells in the developing brain.

Nuclear Receptor TLX Regulates Cell Cycle Progression in Neural Stem Cells of the Developing Brain

PubMed Central

Li, Wenwu; Sun, Guoqiang; Yang, Su; Qu, Qiuhao; Nakashima, Kinichi; Shi, Yanhong

2008-01-01

TLX is an orphan nuclear receptor that is expressed exclusively in vertebrate forebrains. Although TLX is known to be expressed in embryonic brains, the mechanism by which it influences neural development remains largely unknown. We show here that TLX is expressed specifically in periventricular neural stem cells in embryonic brains. Significant thinning of neocortex was observed in embryonic d 14.5 TLX-null brains with reduced nestin labeling and decreased cell proliferation in the germinal zone. Cell cycle analysis revealed both prolonged cell cycles and increased cell cycle exit in TLX-null embryonic brains. Increased expression of a cyclin-dependent kinase inhibitor p21 and decreased expression of cyclin D1 provide a molecular basis for the deficiency of cell cycle progression in embryonic brains of TLX-null mice. Furthermore, transient knockdown of TLX by in utero electroporation led to precocious cell cycle exit and differentiation of neural stem cells followed by outward migration. Together these results indicate that TLX plays an important role in neural development by regulating cell cycle progression and exit of neural stem cells in the developing brain. PMID:17901127

Type 1 and 3 inositol trisphosphate receptors are required for extra-embryonic vascular development.

PubMed

Uchida, Keiko; Nakazawa, Maki; Yamagishi, Chihiro; Mikoshiba, Katsuhiko; Yamagishi, Hiroyuki

2016-10-01

The embryonic-maternal interface of the placental labyrinth, allantois, and yolk sac are vital during embryogenesis; however, the precise mechanism underlying the vascularization of these structures remains unknown. Herein we focus on the role of inositol 1,4,5-trisphosphate (IP3) receptors (IP3R), which are intracellular Ca(2+) release channels, in placentation. Double knockout (DKO) of type 1 and 3 IP3Rs (IP3R1 and IP3R3, respectively) in mice resulted in embryonic lethality around embryonic day (E) 11.5. Because IP3R1 and IP3R3 were co-expressed in endothelial cells in the labyrinth, allantois, and yolk sac, we investigated extra-embryonic vascular development in IP3R1- and IP3R3-DKO mice. The formation of chorionic plates and yolk sac vessels seemed dysregulated around the timing of the chorio-allantoic attachment, immediately followed by the disorganization of allantoic vessels, the decreased expression of the spongiotrophoblast cell marker Tpbpa and the growth retardation of the embryos in DKO mice. Fluorescent immunohistochemistry demonstrated downregulation of a vascular endothelial marker, CD31, in labyrinth embryonic vessels and poor elongation of extra-embryonic mesoderm into the labyrinth layer in DKO placenta, whereas the branching of the DKO chorionic trophoblast was initiated. In addition, allantoic and yolk sac vessels in extra-embryonic tissues were less remodeled in DKO mice. In vitro endothelial cord formation and migration activities of cultured vascular endothelial cells derived from human umbilical vein were downregulated under the inhibition of IP3R. Our results suggest that IP3R1 and IP3R3 are required for extra-embryonic vascularization in the placenta, allantois, and yolk sac. This is the first demonstration of the essential role of IP3/IP3Rs signaling in the development of the vasculature at the embryonic-maternal interface. Copyright © 2016 Elsevier Inc. All rights reserved.

Embryonic integument and "molts" in Manduca sexta (Insecta, Lepidoptera).

PubMed

Ziese, Stefanie; Dorn, August

2003-02-01

In Manduca sexta the germ band is formed 12 h post-oviposition (p.o.) (=10% development completed) and is located above the yolk at the egg surface. The cells show a polar organization. They are engaged in the uptake and degradation of yolk globules, pinched off from the yolk cells. This process can be observed in the integumental cells during the first growth phase of the embryo that lasts until "katatrepsis," an embryonic movement that takes place at 40% development completed. At 37% development completed, the ectoderm deposits a thin membrane at its apical surface, the first embryonic membrane, which detaches immediately before katatrepsis. The second period of embryonic growth--from katatrepsis to 84 h p.o. (70% development completed)--starts with the deposition of a second embryonic membrane that is somewhat thicker than the first one and shows a trilaminar, cuticulin-like structure. Whereas the apical cell surface is largely smooth during the deposition of the first embryonic membrane, it forms microvilli during deposition of the second one. At the same time, uptake of formed yolk material ceases and the epidermal cells now contain clusters of mitochondria below the apical surface. Rough endoplasmic reticulum (RER) increases in the perinuclear region. The second embryonic membrane detaches about 63 h p.o. At 69 h p.o., a new generation of microvilli forms and islands of a typical cuticulin layer indicate the onset of the deposition of the larval cuticle. The third growth phase is characterized by a steady increase in the embryo length, the deposition of the larval procuticle, and by cuticular tanning at about 100 h p.o. Beginning at that stage, electron-lucent vesicles aggregate below the epidermal surface and are apparently released below the larval cuticle. Manduca sexta is the first holometabolous insect in which the deposition of embryonic membranes and cuticles has been examined by electron microscopy. In correspondence with hemimetabolous insects, the embryo of M. sexta secretes three covers at approximately the same developmental stage. A marked difference: the second embryonic cover, which in Hemimetabola clearly exhibits a cuticular organization, has instead a membranous, cuticulin-like structure. We see the difference as the result of an evolutionary reductional process promoted by the redundancy of embryonic covers in the egg shell. Embryonic "molts" also occur in noninsect arthropods; their phylogenetical aspects are discussed. Copyright 2002 Wiley-Liss, Inc.

In utero mouse embryonic imaging with OCT for ophthalmologic research

NASA Astrophysics Data System (ADS)

Syed, Saba H.; Larina, Irina V.; Dickinson, Mary E.; Larin, Kirill V.

2011-03-01

Live imaging of an eye during embryonic development in mammalian model is important for understanding dynamic aspects of normal and abnormal eye morphogenesis. In this study, we used Swept Source Optical Coherence Tomography (SS-OCT) for live structural imaging of mouse embryonic eye through the uterine wall. The eye structure was reconstructed in mouse embryos at 13.5 to 17.5 days post coitus (dpc). Despite the limited imaging depth of OCT in turbid tissues, we were able to visualize the whole eye globe at these stages. These results suggest that live in utero OCT imaging is a useful tool to study embryonic eye development in the mouse model.

Experimental evaluation of reproductive response to climate warming in an oviparous skink.

PubMed

Lu, Hongliang; Wang, Yong; Tang, Wenqi; DU, Weiguo

2013-06-01

The impact of climate warming on organisms is increasingly being recognized. The experimental evaluation of phenotypically plastic responses to warming is a critical step in understanding the biological effects and adaptive capacity of organisms to future climate warming. Oviparous Scincella modesta live in deeply-shaded habitats and they require low optimal temperatures during embryonic development, which makes them suitable subjects for testing the effects of warming on reproduction. We raised adult females and incubated their eggs under different thermal conditions that mimicked potential climate warming. Female reproduction, embryonic development and hatchling traits were monitored to evaluate the reproductive response to warming. Experimental warming induced females to lay eggs earlier, but it did not affect the developmental stage of embryos at oviposition or the reproductive output. The high temperatures experienced by gravid females during warming treatments reduced the incubation period and increased embryonic mortality. The locomotor performance of hatchlings was not affected by the maternal thermal environment, but it was affected by the warming treatment during embryonic development. Our results suggest that climate warming might have a profound effect on fitness-relevant traits both at embryonic and post-embryonic stages in oviparous lizards. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

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.

[Embryonic development of whitefishes (Coregonidae) as representatives of the "pagophilous" ecological group].

PubMed

Cherniaev, Zh A

2013-01-01

Studies of reproduction and embryonic development in six species of coregonid fishes have revealed the possibility of their fertilized eggs to develop normally while being embedded in the ice of a spawning water body (optionally). Such ability is facilitated by extremely low respiratory activity of embryos at early stages of embryogenesis (from the stage of fission to the stage of organogenesis). Low level of oxygen consumption and carbon dioxide emission is an adaptation to low diffusion gas permeability of the ice. The main factor controlling the rate of coregonids embryonic development is not temperature, but intensity and periodicity of insolation. Without the sunlight--an obligatory external factor--normal development is just not possible. Under experimental conditions, when developing in the water at near zero temperature or in the ice, normal morphogenesis of Arctic cisco and Sevan whitefish embryos was observed at the illumination of 50-300 lux. Hemoproteid cytochrome beta560, the pigment that has been discovered in water-soluble part of coregonids oocyte yolk and is treated as a biochemical marker for eggs of the family Coregonidae, in all likelihood performs protective (antioxidant) functions preventing spontaneous oxidation of embryo's fatty inclusions. Under the oxygen shortage inside the ice envelope, cytochrome beta560 probably sets conditions for oxidation processes of embryo's tissue respiration. Spherome, being kept till the time of hatching, acts as a temporary hydrostatic organ and ensures larvae buoyancy at the stage of postembryonic metamorphosis. It also serves as an energy store after downstream migration of larvae from the spawning areas till their shift to exogenous feeding on zooplankton. Conforming to ecological traits of reproduction and development, and also to revealed morphogenetic, physiological, and biochemical features, it is proposed to ascribe all of the currently known 26 species of whitefishes to "pagophilous" ecological group.

Adverse Outcome Pathways for Embryonic Vascular Disruption and Alternative Methods to Identify Chemical Vascular Disruptor

EPA Science Inventory

Chemically induced vascular toxicity during embryonic development can result in a wide range of adverse prenatal outcomes. We used information from genetic mouse models linked to phenotypic outcomes and a vascular toxicity knowledge base to construct an embryonic vascular disrupt...

Case Study: Organotypic human in vitro models of embryonic morphogenetic fusion

EPA Science Inventory

Morphogenetic fusion of tissues is a common event in embryonic development and disruption of fusion is associated with birth defects of the eye, heart, neural tube, phallus, palate, and other organ systems. Embryonic tissue fusion requires precise regulation of cell-cell and cell...

Standard metabolic rates of early life stages of the diamondback terrapin (Malaclemys terrapin), an estuarine turtle, suggest correlates between life history changes and the metabolic economy of hatchlings.

PubMed

Rowe, Christopher L

2018-04-01

I estimated standard metabolic rates (SMR) using measurements of oxygen consumption rates of embryos and unfed, resting hatchlings of the diamondback terrapin (Malaclemys terrapin) three times during embryonic development and twice during the early post-hatching period. The highest observed SMRs occurred during mid to late embryonic development and the early post-hatching period when hatchlings were still reliant on yolk reserves provided by the mother. Hatchlings that were reliant on yolk displayed per capita SMR 135 % higher than when measured 25 calendar days later after they became reliant on exogenous resources. The magnitude of the difference in hatchling SMR between yolk-reliant and exogenously feeding stages was much greater than that attributed to costs of digestion (specific dynamic action) observed in another emydid turtle, suggesting that processing of the yolk was not solely responsible for the observed difference. The pre-feeding period of yolk reliance of hatchlings corresponds with the period of dispersal from the nesting site, suggesting that elevated SMR during this period could facilitate dispersal activities. Thus, I hypothesize that the reduction in SMR after the development of feeding behaviors may reflect an energy optimization strategy in which a high metabolic expenditure in support of development and growth of the embryo and dispersal of the hatchling is followed by a substantial reduction in metabolic expenditure coincident with the individual becoming reliant on exogenous resources following yolk depletion. Copyright © 2018 Elsevier GmbH. All rights reserved.

Effects of different feeder layers on culture of bovine embryonic stem cell-like cells in vitro.

PubMed

Cong, Shan; Cao, Guifang; Liu, Dongjun

2014-12-01

To find a suitable feeder layer is important for successful culture conditions of bovine embryonic stem cell-like cells. In this study, expression of pluripotency-related genes OCT4, SOX2 and NANOG in bovine embryonic stem cell-like cells on mouse embryonic fibroblast feeder layers at 1-5 passages were monitored in order to identify the possible reason that bovine embryonic stem cell-like cells could not continue growth and passage. Here, we developed two novel feeder layers, mixed embryonic fibroblast feeder layers of mouse and bovine embryonic fibroblast at different ratios and sources including mouse fibroblast cell lines. The bovine embryonic stem cell-like cells generated in our study displayed typical stem cell morphology and expressed specific markers such as OCT4, stage-specific embryonic antigen 1 and 4, alkaline phosphatase, SOX2, and NANOG mRNA levels. When feeder layers and cell growth factors were removed, the bovine embryonic stem cell-like cells formed embryoid bodies in a suspension culture. Furthermore, we compared the expression of the pluripotent markers during bovine embryonic stem cell-like cell in culture on mixed embryonic fibroblast feeder layers, including mouse fibroblast cell lines feeder layers and mouse embryonic fibroblast feeder layers by real-time quantitative polymerase chain reaction. Results suggested that mixed embryonic fibroblast and sources including mouse fibroblast cell lines feeder layers were more suitable for long-term culture and growth of bovine embryonic stem cell-like cells than mouse embryonic fibroblast feeder layers. The findings may provide useful experimental data for the establishment of an appropriate culture system for bovine embryonic stem cell lines.

Large-scale production of embryonic red blood cells from human embryonic stem cells.

PubMed

Olivier, Emmanuel N; Qiu, Caihong; Velho, Michelle; Hirsch, Rhoda Elison; Bouhassira, Eric E

2006-12-01

To develop a method to produce in culture large number of erythroid cells from human embryonic stem cells. Human H1 embryonic stem cells were differentiated into hematopoietic cells by coculture with a human fetal liver cell line, and the resulting CD34-positive cells were expanded in vitro in liquid culture using a three-step method. The erythroid cells produced were then analyzed by light microscopy and flow cytometry. Globin expression was characterized by quantitative reverse-transcriptase polymerase chain reaction and by high-performance liquid chromatography. CD34-positive cells produced from human embryonic stem cells could be efficiently differentiated into erythroid cells in liquid culture leading to a more than 5000-fold increase in cell number. The erythroid cells produced are similar to primitive erythroid cells present in the yolk sac of early human embryos and did not enucleate. They are fully hemoglobinized and express a mixture of embryonic and fetal globins but no beta-globin. We have developed an experimental protocol to produce large numbers of primitive erythroid cells starting from undifferentiated human embryonic stem cells. As the earliest human erythroid cells, the nucleated primitive erythroblasts, are not very well characterized because experimental material at this stage of development is very difficult to obtain, this system should prove useful to answer a number of experimental questions regarding the biology of these cells. In addition, production of mature red blood cells from human embryonic stem cells is of great potential practical importance because it could eventually become an alternate source of cell for transfusion.

Maternal dietary manganese protects chick embryos against maternal heat stress via epigenetic-activated antioxidant and anti-apoptotic abilities.

PubMed

Zhu, Yongwen; Lu, Lin; Liao, Xiudong; Li, Wenxiang; Zhang, Liyang; Ji, Cheng; Lin, Xi; Liu, Hsiao-Ching; Odle, Jack; Luo, Xugang

2017-10-27

Maternal heat stress induced the aberrant epigenetic patterns resulting in the abnormal development of offspring embryos. It is unclear whether maternal dietary manganese supplementation as an epigenetic modifier could protect the chick embryonic development against maternal heat stress via epigenetic mechanisms. To test this hypothesis using an avian model, a completely randomized design with a 2 (maternal normal and high environmental temperatures of 21 and 32°C, respectively) × 3 (maternal dietary manganese sources, the control diet without manganese supplementation and the control diet + 120 mg/kg as either inorganic or organic manganese) factorial arrangement was adopted. Maternal environmental hyperthermia increased mRNA expressions of heat shock proteins 90 and 70, cyclin-dependent kinase 6 and B-cell CLL/lymphoma 2-associated X protein displaying oxidative damage and apoptosis in the embryonic heart. Maternal environmental hyperthermia impaired the embryonic development associated with the alteration of epigenetic status, as evidenced by global DNA hypomethylation and histone 3 lysine 9 hypoacetylation in the embryonic heart. Maternal dietary manganese supplementation increased the heart anti-apoptotic gene B-cell CLL/lymphoma 2 expressions under maternal environmental hyperthermia and manganese superoxide dismutase enzyme activity in the embryonic heart. Maternal dietary organic Mn supplementation effectively eliminated the impairment of maternal environmental hyperthermia on the embryonic development. Maternal dietary manganese supplementation up-regulated manganese superoxide dismutase mRNA expression by reducing DNA methylation and increasing histone 3 lysine 9 acetylation of its promoter. It is suggested that maternal dietary manganese addition could protect the chick embryonic development against maternal heat stress via enhancing epigenetic-activated antioxidant and anti-apoptotic abilities.

Arabidopsis LEAFY COTYLEDON1 controls cell fate determination during post-embryonic development

PubMed Central

Huang, Mingkun; Hu, Yilong; Liu, Xu; Li, Yuge; Hou, Xingliang

2015-01-01

Arabidopsis LEAFY COTYLEDON1 (LEC1) transcription factor is a master regulator that shapes plant embryo development and post-embryonic seedling establishment. Loss-of-function of LEC1 alters the cotyledon identity, causing the formation of ectopic trichomes, which does not occur in wild-type seedlings, implying that LEC1 might regulate embryonic cell fate determination during post-embryonic development. To test this hypothesis, we compared the expression of trichome development-related genes between the wild-type and the lec1 mutant. We observed that transcripts of GLABROUS1 (GL1), GL2, and GL3, genes encoding the positive regulators in trichome development, were significantly upregulated, while the TRICHOMELESS1 (TCL2), ENHANCER OF TRY AND CPC1 (ETC1), and ETC2 genes, encoding the negative regulators in trichome development, were downregulated in the lec1 mutant. Furthermore, overexpression of LEC1 activated the expressions of TCL2, CAPPICE (CPC), and ETC1, resulting in production of cotyledonary leaves with no or fewer trichomes during vegetative development. In addition, we demonstrated that LEC1 interacts with TCL2 in yeast and in vitro. A genetic experiment showed that loss-of-function of GL2 rescued the ectopic trichome formation in the lec1 mutant. These findings strongly support that LEC1 regulates trichome development, providing direct evidence for the role of LEC1 in cell fate determination during post-embryonic development. PMID:26579186

ModuleMiner - improved computational detection of cis-regulatory modules: are there different modes of gene regulation in embryonic development and adult tissues?

PubMed Central

Van Loo, Peter; Aerts, Stein; Thienpont, Bernard; De Moor, Bart; Moreau, Yves; Marynen, Peter

2008-01-01

We present ModuleMiner, a novel algorithm for computationally detecting cis-regulatory modules (CRMs) in a set of co-expressed genes. ModuleMiner outperforms other methods for CRM detection on benchmark data, and successfully detects CRMs in tissue-specific microarray clusters and in embryonic development gene sets. Interestingly, CRM predictions for differentiated tissues exhibit strong enrichment close to the transcription start site, whereas CRM predictions for embryonic development gene sets are depleted in this region. PMID:18394174

Major advances associated with reproduction in dairy cattle.

PubMed

Moore, K; Thatcher, W W

2006-04-01

The purpose of this overview is to review some of the major advances in reproductive technologies, and how they may be applied to meet the challenge of enhancing reproductive efficiency in the high-producing dairy cow of the 21st century. The current population of high-producing dairy cows is considered to be subfertile, as characterized by low pregnancy rates and high rates of embryonic mortality. Coordinated systems of reproductive management have been developed based upon a thorough understanding of the endocrine, cellular, and molecular factors controlling ovarian and uterine function. These systems will partially restore herd reproductive performance. Advances in other reproductive technologies offer possibilities for wider use of superior germplasm. Technologies such as sexed semen, cloning, transgenesis, and preimplantation genetic diagnosis offer the potential to enhance the influence of superior animals on production of food for human consumption. However, at this time, additional research is needed to counteract the higher rates of embryonic and fetal mortality associated with some of these technologies. Furthermore, use of genomics, proteomics, and bioinformatics in the study of reproduction will undoubtedly provide investigators with a greater understanding of the limitations to efficient reproductive processes in the subfertile lactating dairy cow.

Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) assay

EPA Science Inventory

The Embryonic Stem Cell Test (EST) is an assay which evaluates xenobiotic-induced effects using three endpoints: mouse embryonic stem cell (mESC) differentiation, mESC viability, and 3T3-cell viability. Our research goal was to develop an improved high-throughput assay by establi...

Embryonic and larval development and early behavior in grass carp, Ctenopharyngodon idella: implications for recruitment in rivers

USGS Publications Warehouse

George, Amy E.; Chapman, Duane C.

2015-01-01

With recent findings of grass carp Ctenopharyngodon idella in tributaries of the Great Lakes, information on developmental rate and larval behavior is critical to efforts to assess the potential for establishment within the tributaries of that region. In laboratory experiments, grass carp were spawned and eggs and larvae reared at two temperature treatments, one "cold" and one "warm", and tracked for developmental rate, egg size, and behavior. Developmental rate was quantified using Yi's (1988) developmental stages and the cumulative thermal units method. Grass carp had a thermal minimum of 13.5°C for embryonic stages and 13.3°C for larval stages. Egg size was related to temperature and maternal size, with the largest eggs coming from the largest females, and eggs were generally larger in warmer treatments. Young grass carp larvae exhibited upward and downward swimming interspersed with long periods of lying on the bottom. Swimming capacity increased with ontogeny, and larvae were capable of horizontal swimming and position holding with gas bladder emergence. Developmental rates, behavior, and egg attributes can be used in combination with physical parameters of a river to assess the risk that grass carp are capable of reproduction and recruitment in rivers.

The embryonic development of the cnidarian Hydractinia echinata.

PubMed

Kraus, Yulia; Flici, Hakima; Hensel, Katrin; Plickert, Günter; Leitz, Thomas; Frank, Uri

2014-01-01

With the rapid increase of the quantity of molecular data, many animals joined the ranks of the so-called 'emerging models' of Evo-Devo. One of the necessary steps in converting an emerging model into an established one is gaining comprehensive knowledge of its normal embryonic development. The marine colonial hydrozoan Hydractinia echinata - an excellent model for research on stem cells, metamorphosis, and allorecognition - has been studied for decades. Yet knowledge of its embryonic development remains fragmentary and incomplete. Here we provide a detailed account of H. echinata embryonic development using in vivo observations, histology, immunohistochemistry, and electron microscopy. Furthermore, we propose a model describing the cellular basis of the morphogenetic movements occurring during development and also reveal a functional link between canonical Wnt signaling and regional differences in the morphology of the embryo. Hydractinia embryogenesis is an example of the diversity and plasticity of hydrozoan development where multiple routes lead to the same result - the formation of a normal planula larva. © 2014 Wiley Periodicals, Inc.

Structure and function of gap junction proteins: role of gap junction proteins in embryonic heart development.

PubMed

Ahir, Bhavesh K; Pratten, Margaret K

2014-01-01

Intercellular (cell-to-cell) communication is a crucial and complex mechanism during embryonic heart development. In the cardiovascular system, the beating of the heart is a dynamic and key regulatory process, which is functionally regulated by the coordinated spread of electrical activity through heart muscle cells. Heart tissues are composed of individual cells, each bearing specialized cell surface membrane structures called gap junctions that permit the intercellular exchange of ions and low molecular weight molecules. Gap junction channels are essential in normal heart function and they assist in the mediated spread of electrical impulses that stimulate synchronized contraction (via an electrical syncytium) of cardiac tissues. This present review describes the current knowledge of gap junction biology. In the first part, we summarise some relevant biochemical and physiological properties of gap junction proteins, including their structure and function. In the second part, we review the current evidence demonstrating the role of gap junction proteins in embryonic development with particular reference to those involved in embryonic heart development. Genetics and transgenic animal studies of gap junction protein function in embryonic heart development are considered and the alteration/disruption of gap junction intercellular communication which may lead to abnormal heart development is also discussed.

Embryonic metabolism of the ornithischian dinosaurs Protoceratops andrewsi and Hypacrosaurus stebingeri and implications for calculations of dinosaur egg incubation times

NASA Astrophysics Data System (ADS)

Lee, Scott A.

2017-04-01

The embryonic metabolisms of the ornithischian dinosaurs Protoceratops andrewsi and Hypacrosaurus stebingeri have been determined and are in the range observed in extant reptiles. The average value of the measured embryonic metabolic rates for P. andrewsi and H. stebingeri are then used to calculate the incubation times for 21 dinosaurs from both Sauischia and Ornithischia using a mass growth model based on conservation of energy. The calculated incubation times vary from about 70 days for Archaeopteryx lithographica to about 180 days for Alamosaurus sanjuanensis. Such long incubation times seem unlikely, particularly for the sauropods and large theropods. Incubation times are also predicted with the assumption that the saurischian dinosaurs had embryonic metabolisms in the range observed in extant birds.

Embryonic metabolism of the ornithischian dinosaurs Protoceratops andrewsi and Hypacrosaurus stebingeri and implications for calculations of dinosaur egg incubation times.

PubMed

Lee, Scott A

2017-04-01

The embryonic metabolisms of the ornithischian dinosaurs Protoceratops andrewsi and Hypacrosaurus stebingeri have been determined and are in the range observed in extant reptiles. The average value of the measured embryonic metabolic rates for P. andrewsi and H. stebingeri are then used to calculate the incubation times for 21 dinosaurs from both Sauischia and Ornithischia using a mass growth model based on conservation of energy. The calculated incubation times vary from about 70 days for Archaeopteryx lithographica to about 180 days for Alamosaurus sanjuanensis. Such long incubation times seem unlikely, particularly for the sauropods and large theropods. Incubation times are also predicted with the assumption that the saurischian dinosaurs had embryonic metabolisms in the range observed in extant birds.

Early intrauterine embryonic development in Khawia sinensis Hsü, 1935 (Cestoda, Caryophyllidea, Lytocestidae), an invasive tapeworm of carp (Cyprinus carpio): an ultrastructural study.

PubMed

Bruňanská, Magdaléna; Mackiewicz, John S; Młocicki, Daniel; Swiderski, Zdzisław; Nebesářová, Jana

2012-02-01

Intrauterine embryonic development in the caryophyllidean tapeworm Khawia sinensis has been investigated using transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for glycogen. Contrary to previous light microscopy findings that reported the release of non-embryonated eggs of K. sinenesis to the external environment, the present study documents various stages of embryonation (ovoviviparity) within the intrauterine eggs of this cestode. At the initial stage of embryonic development, each fertilised oocyte is accompanied by several vitellocytes that become enclosed within the operculate, electrondense shell. Cleavage divisions result in formation of blastomeres (up to about 24 cells) of various sizes. Mitotic divisions and apparent rosette arrangment of the blastomeres, the latter atypical within the Eucestoda, are observed for the first time in the intrauterine eggs of K. sinenesis. The early embryo enclosed within the electrondense shell is surrounded by a thin membraneous layer which in some enlarged regions shows presence of nuclei. Simultaneously to multiplication and differentiation, some of the blastomeres undergo deterioration. A progressive degeneration of the vitellocytes within eggs provides nutritive reserves, including lipids, for the developing embryo. The possible significance of this atypical timing of the intrauterine embryonic development to (1) the ecology of K. sinensis and that of a recent introduction of another invasive tapeworm, the caryophyllidean Atractolytocestus huronensis Anthony, 1958 to Europe; and (2) the affiliation of caryophyllideans with other lower cestodes, are discussed.

Does the oviparity-viviparity transition alter the partitioning of yolk in embryonic snakes?

PubMed

Wu, Yan-Qing; Qu, Yan-Fu; Wang, Xue-Ji; Gao, Jian-Fang; Ji, Xiang

2017-11-29

The oviparity-viviparity transition is a major evolutionary event, likely altering the reproductive process of the organisms involved. Residual yolk, a portion of yolk remaining unutilized at hatching or birth as parental investment in care, has been investigated in many oviparous amniotes but remained largely unknown in viviparous species. Here, we used data from 20 (12 oviparous and 8 viviparous) species of snakes to see if the oviparity-viviparity transition alters the partitioning of yolk in embryonic snakes. We used ANCOVA to test whether offspring size, mass and components at hatching or birth differed between the sexes in each species. We used both ordinary least squares and phylogenetic generalized least squares regressions to test whether relationships between selected pairs of offspring components were significant. We used phylogenetic ANOVA to test whether offspring components differed between oviparous and viviparous species and, more specifically, the hypothesis that viviparous snakes invest more in the yolk as parental investment in embryogenesis to produce more well developed offspring that are larger in linear size. In none of the 20 species was sex a significant source of variation in any offspring component examined. Newborn viviparous snakes on average contained proportionally more water and, after accounting for body dry mass, had larger carcasses but smaller residual yolks than did newly hatched oviparous snakes. The rates at which carcass dry mass (CDM) and fat body dry mass (FDM) increased with residual yolk dry mass (YDM) did not differ between newborn oviparous and viviparous snakes. Neither CDM nor FDM differed between newborn oviparous and viviparous snakes after accounting for YDM. Our results are not consistent with the hypothesis that the partitioning of yolk between embryonic and post-embryonic stages differs between snakes that differ in parity mode, but instead show that the partitioning of yolk in embryonic snakes is species-specific or phylogenetically related. We conclude that the oviparity-viviparity transition does not alter yolk partitioning in embryonic snakes.

Normal embryonic and germ cell development in mice lacking alpha 1,3-fucosyltransferase IX (Fut9) which show disappearance of stage-specific embryonic antigen 1.

PubMed

Kudo, Takashi; Kaneko, Mika; Iwasaki, Hiroko; Togayachi, Akira; Nishihara, Shoko; Abe, Kuniya; Narimatsu, Hisashi

2004-05-01

Stage-specific embryonic antigen 1 (SSEA-1), an antigenic epitope defined as a Lewis x carbohydrate structure, is expressed during the 8-cell to blastocyst stages in mouse embryos and in primordial germ cells, undifferentiated embryonic stem cells, and embryonic carcinoma cells. For many years, SSEA-1 has been implicated in the development of mouse embryos as a functional carbohydrate epitope in cell-to-cell interaction during morula compaction. In a previous study, alpha 1,3-fucosyltransferase IX (Fut9) exhibited very strong activity for the synthesis of Lewis x compared to other alpha 1,3-fucosyltransferases in an in vitro substrate specificity assay. Fut4 and Fut9 transcripts were expressed in mouse embryos. The Fut9 transcript was detected in embryonic-day-13.5 gonads containing primordial germ cells, but the Fut4 transcript was not. In order to identify the role of SSEA-1 and determine the key enzyme for SSEA-1 synthesis in vivo, we have generated Fut9-deficient (Fut9(-/-)) mice. Fut9(-/-) mice develop normally, with no gross phenotypic abnormalities, and are fertile. Immunohistochemical analysis revealed an absence of SSEA-1 expression in early embryos and primordial germ cells of Fut9(-/-) mice. Therefore, we conclude that expression of the SSEA-1 epitope in the developing mouse embryo is not essential for embryogenesis in vivo.

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.

Effects of nonylphenol on early embryonic development, pigmentation and 3,5,3'-triiodothyronine-induced metamorphosis in Bombina orientalis (Amphibia: Anura).

PubMed

Park, Chan Jin; Kang, Han Seung; Gye, Myung Chan

2010-11-01

Nonylphenol (NP) is an estrogenic endocrine disruptor in many aquatic species. In an effort to highlight the developmental toxicity of NP in amphibians, we examined the effects of NP on the embryonic survival, tadpole growth, melanophore development and metamorphosis of a native Korean amphibian species, Bombina orientalis (Anura). When treated to fertilized eggs, 1 μM NP significantly decreased embryonic survival at 48 h post fertilization (p.f.), suggesting that 1 μM NP can exert systemic toxicity in B. orientalis embryos. In the surviving embryos, there were no significant differences in malformation rates between NP-treated embryos and controls at 240 h p.f., suggesting no or low teratogenicity of NP in B. orientalis embryos. Below LC(50) NP significantly decreased body growth and development of melanophores at 0.1 μM, suggesting that NP far below the LC(50) targets multiple developmental events in tadpoles of this frog species. In metamorphosis assay using the premetamorphic tadpoles (corresponding to Nieuwkoop Faber stage 53 in Xenopus laevis) exogenous 3,5,3'-triiodothyronine (T3)-induced tail resorption was significantly decreased by 1 μM NP. However, NP (0.1 and 1 μM)-only treatment did not affected total body T3 and T4 levels, suggesting that NP at tested concentrations inhibits thyroid hormones action but not the synthesis of hormones during metamorphosis. Copyright © 2010 Elsevier Ltd. All rights reserved.

Increasing levels of estradiol are deleterious to embryonic implantation because they directly affect the embryo.

PubMed

Valbuena, D; Martin, J; de Pablo, J L; Remohí, J; Pellicer, A; Simón, C

2001-11-01

To investigate whether the deleterious effect of E(2) on embryonic implantation is due to a direct effect on the endometrium, on the embryo, or both. Prospective, controlled in vitro study. Tertiary infertility center. Fertile patients in the luteal phase with histologically normal endometrium who were attending the infertility clinic as oocyte donors (n = 14). E(2) dose-response (0, 10(-8), 10(-7), 10(-6), 10(-5), and 10(-4) M) and time course (day 2 vs. day 5) experiments were performed in an in vitro embryo adhesion assay composed of human polarized endometrial epithelial cells obtained from fertile patients and mouse embryos. Blastocyst formation rate and embryo adhesion rate. Monolayers of polarized endometrial epithelial cells expressed ERalpha at the mRNA level. The E(2) dose response of blastocysts with polarized endometrial epithelial cells (n = 235) demonstrated a progressive reduction in embryonic adhesion that was statistically significant at 10(-6) M. When polarized endometrial epithelial cells were treated alone with increasing doses of E(2) for 3 days and E(2) was then removed and blastocysts added (n = 410), embryonic adhesion was not significantly reduced, except at 10(-4) M. When 2-day mouse embryos (n = 609) were treated with increasing E(2) concentrations until day 5, the rate of blastocyst formation significantly decreased at a concentration >or= 10(-6) M, and embryonic adhesion decreased when blastocysts (n = 400) were obtained at a concentration >or= 10(-7) M. Time course experiments of embryos cultured for 2 days with polarized endometrial epithelial cells (n = 426) showed that the adhesion rate was higher at E(2) levels of 10(-7), 10(-6) and 10(-5) M compared with embryos cultured for 5 days (n = 495). High E(2) levels are deleterious to embryo adhesion in vitro, mainly because they have a direct toxic effect on the embryo that may occur at the cleavage stage.

DNA methylation, an epigenetic mechanism connecting folate to healthy embryonic development and aging

USDA-ARS?s Scientific Manuscript database

Experimental studies demonstrated that maternal environmental factors including diet during early embryonic development can influence the phenotype of offspring as well as the risk of disease development at the later life. DNA methylation, an epigenetic phenomenon, has been suggested as a mechanism ...

Contractile properties of early human embryonic stem cell-derived cardiomyocytes: beta-adrenergic stimulation induces positive chronotropy and lusitropy but not inotropy.

PubMed

Pillekamp, Frank; Haustein, Moritz; Khalil, Markus; Emmelheinz, Markus; Nazzal, Rewa; Adelmann, Roland; Nguemo, Filomain; Rubenchyk, Olga; Pfannkuche, Kurt; Matzkies, Matthias; Reppel, Michael; Bloch, Wilhelm; Brockmeier, Konrad; Hescheler, Juergen

2012-08-10

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) provide the unique opportunity to study the very early development of the human heart. The aim of this study was to investigate the effect of calcium and beta-adrenergic stimulation on the contractile properties of early hESC-CMs. Beating clusters containing hESC-CMs were co-cultured in vitro with noncontractile slices of neonatal murine ventricles. After 5-7 days, when beating clusters had integrated morphologically into the damaged tissue, isometric force measurements were performed during spontaneous beating as well as during electrical field stimulation. Spontaneous beating stopped when extracellular calcium ([Ca²⁺](ec)) was removed or after administration of the Ca²⁺ channel blocker nifedipine. During field stimulation at a constant rate, the developed force increased with incremental concentrations of [Ca²⁺](ec). During spontaneous beating, rising [Ca²⁺](ec) increased beating rate and developed force up to a [Ca²⁺](ec) of 2.5 mM. When [Ca²⁺](ec) was increased further, spontaneous beating rate decreased, whereas the developed force continued to increase. The beta-adrenergic agonist isoproterenol induced a dose-dependent increase of the frequency of spontaneous beating; however, it did not significantly change the developed force during spontaneous contractions or during electrical stimulation at a constant rate. Force developed by early hESC-CMs depends on [Ca²⁺](ec) and on the L-type Ca²⁺ channel. The lack of an inotropic reaction despite a pronounced chronotropic response after beta-adrenergic stimulation most likely indicates immaturity of the sarcoplasmic reticulum. For cell-replacement strategies, further maturation of cardiac cells has to be achieved either in vitro before or in vivo after transplantation.

A toolbox to explore the mechanics of living embryonic tissues

PubMed Central

Campàs, Otger

2016-01-01

The sculpting of embryonic tissues and organs into their functional morphologies involves the spatial and temporal regulation of mechanics at cell and tissue scales. Decades of in vitro work, complemented by some in vivo studies, have shown the relevance of mechanical cues in the control of cell behaviors that are central to developmental processes, but the lack of methodologies enabling precise, quantitative measurements of mechanical cues in vivo have hindered our understanding of the role of mechanics in embryonic development. Several methodologies are starting to enable quantitative studies of mechanics in vivo and in situ, opening new avenues to explore how mechanics contributes to shaping embryonic tissues and how it affects cell behavior within developing embryos. Here we review the present methodologies to study the role of mechanics in living embryonic tissues, considering their strengths and drawbacks as well as the conditions in which they are most suitable. PMID:27061360

A toolbox to explore the mechanics of living embryonic tissues.

PubMed

Campàs, Otger

2016-07-01

The sculpting of embryonic tissues and organs into their functional morphologies involves the spatial and temporal regulation of mechanics at cell and tissue scales. Decades of in vitro work, complemented by some in vivo studies, have shown the relevance of mechanical cues in the control of cell behaviors that are central to developmental processes, but the lack of methodologies enabling precise, quantitative measurements of mechanical cues in vivo have hindered our understanding of the role of mechanics in embryonic development. Several methodologies are starting to enable quantitative studies of mechanics in vivo and in situ, opening new avenues to explore how mechanics contributes to shaping embryonic tissues and how it affects cell behavior within developing embryos. Here we review the present methodologies to study the role of mechanics in living embryonic tissues, considering their strengths and drawbacks as well as the conditions in which they are most suitable. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fibroblast growth factor receptors in in vitro and in vivo chondrogenesis: relating tissue engineering using adult mesenchymal stem cells to embryonic development.

PubMed

Hellingman, Catharine A; Koevoet, Wendy; Kops, Nicole; Farrell, Eric; Jahr, Holger; Liu, Wei; Baatenburg de Jong, Robert J; Frenz, Dorothy A; van Osch, Gerjo J V M

2010-02-01

Adult mesenchymal stem cells (MSCs) are considered promising candidate cells for therapeutic cartilage and bone regeneration. Because tissue regeneration and embryonic development may involve similar pathways, understanding common pathways may lead to advances in regenerative medicine. In embryonic limb development, fibroblast growth factor receptors (FGFRs) play a role in chondrogenic differentiation. The aim of this study was to investigate and compare FGFR expression in in vivo embryonic limb development and in vitro chondrogenesis of MSCs. Our study showed that in in vitro chondrogenesis of MSCs three sequential stages can be found, as in embryonic limb development. A mesenchymal condensation (indicated by N-cadherin) is followed by chondrogenic differentiation (indicated by collagen II), and hypertrophy (indicated by collagen X). FGFR1-3 are expressed in a stage-dependent pattern during in vitro differentiation and in vivo embryonic limb development. In both models FGFR2 is clearly expressed by cells in the condensation phase. No FGFR expression was observed in differentiating and mature hyaline chondrocytes, whereas hypertrophic chondrocytes stained strongly for all FGFRs. To evaluate whether stage-specific modulation of chondrogenic differentiation in MSCs is possible with different subtypes of FGF, FGF2 and FGF9 were added to the chondrogenic medium during different stages in the culture process (early or late). FGF2 and FGF9 differentially affected the amount of cartilage formed by MSCs depending on the stage in which they were added. These results will help us understand the role of FGF signaling in chondrogenesis and find new tools to monitor and control chondrogenic differentiation.

Student Learning of Early Embryonic Development via the Utilization of Research Resources from the Nematode "Caenorhabditis elegans"

ERIC Educational Resources Information Center

Lu, Fong-Mei; Eliceiri, Kevin W.; Squirrell, Jayne M.; White, John G.; Stewart, James

2008-01-01

This study was undertaken to gain insights into undergraduate students' understanding of early embryonic development, specifically, how well they comprehend the concepts of volume constancy, cell lineages, body plan axes, and temporal and spatial dimensionality in development. To study student learning, a curriculum was developed incorporating…

Effects of maternal blood loss on embryonic and placental development in the rat.

PubMed

Bruce, N W; Cabral, D A

1975-11-01

The effects of acute loss of maternal blood on embryonic and placental development was examined in 50 rats on Days 8 or 9 of gestation. Blood was withdrawn from conscious, cannulated rats over a 1-min period at 1-0 or 2-0 ml/100 g body weight. These degrees of blood loss were expected to produce a mild (about 50%) and severe (about 80%) reduction in uterine blood flow, respectively, for at least 15 min. There was no evidence that loss of blood affected either fetal survival and malformation rates or fetal weights and sex ratios. The anaemia resulting from haemorrhage lasted no longer than 6 days. Placental weights were 11% higher in rats losing 2-0 ml blood/100 g than in controls (P less than 0-05). It appears that the 8- or 9- day rat embryo is highly resistant to the partial reduction in uterine blood flow, maternal anaemia and other possible challenges induced by maternal loss of blood at levels sufficient to affect the mothers.

Nest success, cause-specific nest failure, and hatchability of aquatic birds at selenium-contaminated Kesterson Reservoir and a reference site

USGS Publications Warehouse

Ohlendorf, Harry M.; Hothem, Roger L.; Welsh, Daniel

1989-01-01

During 1983-1985, we studied the reproductive success of several species of aquatic birds (coots, ducks, shorebirds, and grebes) nesting at two sites in Merced County, California: a selenium-contaminated site (Kesterson Reservoir) and a nearby reference site (Volta Wildlife Area). We used a computer program (MICROMORT) developed for the analysis of radiotelemetry data (Heisey and Fuller 1985) to estimate nest success and cause-specific failure rates, and then compared these parameters and hatchability between sites and among years. Nest success and causes of failure varied by species, site, and year. The most important causes of nest failure were usually predation, desertion, and water-level changes. However, embryotoxicosis (mortality, deformity, and lack of embryonic development) was the most important cause of nest failure in Eared Grebes (Podiceps nigricollis) at Kesterson Reservoir. Embryotoxicosis also reduced the hatchability of eggs of all other species at Kesterson in one or more years; embryonic mortality occurred rarely at Volta, and abnormalities were not observed.

Preserving and Using Germplasm and Dissociated Embryonic Cells for Conserving Caribbean and Pacific Coral

PubMed Central

Hagedorn, Mary; Carter, Virginia; Martorana, Kelly; Paresa, Malia K.; Acker, Jason; Baums, Iliana B.; Borneman, Eric; Brittsan, Michael; Byers, Michael; Henley, Michael; Laterveer, Michael; Leong, Jo-Ann; McCarthy, Megan; Meyers, Stuart; Nelson, Brian D.; Petersen, Dirk; Tiersch, Terrence; Uribe, Rafael Cuevas; Woods, Erik; Wildt, David

2012-01-01

Coral reefs are experiencing unprecedented degradation due to human activities, and protecting specific reef habitats may not stop this decline, because the most serious threats are global (i.e., climate change), not local. However, ex situ preservation practices can provide safeguards for coral reef conservation. Specifically, modern advances in cryobiology and genome banking could secure existing species and genetic diversity until genotypes can be introduced into rehabilitated habitats. We assessed the feasibility of recovering viable sperm and embryonic cells post-thaw from two coral species, Acropora palmata and Fungia scutaria that have diffferent evolutionary histories, ecological niches and reproductive strategies. In vitro fertilization (IVF) of conspecific eggs using fresh (control) spermatozoa revealed high levels of fertilization (>90% in A. palmata; >84% in F. scutaria; P>0.05) that were unaffected by tested sperm concentrations. A solution of 10% dimethyl sulfoxide (DMSO) at cooling rates of 20 to 30°C/min most successfully cryopreserved both A. palmata and F. scutaria spermatozoa and allowed producing developing larvae in vitro. IVF success under these conditions was 65% in A. palmata and 53% in F. scutaria on particular nights; however, on subsequent nights, the same process resulted in little or no IVF success. Thus, the window for optimal freezing of high quality spermatozoa was short (∼5 h for one night each spawning cycle). Additionally, cryopreserved F. scutaria embryonic cells had∼50% post-thaw viability as measured by intact membranes. Thus, despite some differences between species, coral spermatozoa and embryonic cells are viable after low temperature (−196°C) storage, preservation and thawing. Based on these results, we have begun systematically banking coral spermatozoa and embryonic cells on a large-scale as a support approach for preserving existing bio- and genetic diversity found in reef systems. PMID:22413020

Embryonic Developmental Stages of African Giant Catfish Heterobranchus longifilis (Valenciennes, 1840) (Teleostei, Clariidae)

NASA Astrophysics Data System (ADS)

Wilfred-Ekprikpo, P. C.

2016-02-01

One of the major challenges confronting the globe is the issue of food insecurity. This problem results from inadequate protein intake by humans especially those people from the third world countries. In order to arrest this ugly situation, there is the need to increase protein production by intensifying aquaculture. In sub-saharan Africa, particularly Nigeria, the major aquaculture species is African mud catfish (Clarias gariepinus) and its production has increase protein output but the protein deficit is still wide. Thus, necessitating the need to develop other aquaculture species endemic to the region. One of these species is Heterobranchus and there successful breeding depending on a good understanding of their biology. The embryonic developmental stages of Heterobranchus longifilis in freshwater tanks were determined. The first cleavage cell division occurred 30 minutes after fertilization of eggs while, the morula stage was observed within 2 hours. The blastula stage occurred between 2 and 8 hours, while the gastrula stage occurred between 12 and 18 hours. Thereafter, neurulation period, and embryonic body formation appeared. The optical vesicle and auditory vesicle formed. Finally muscular contraction, tail formation, heartbeat and hatching occurred. The embryonic developmental stage of H. longifilis started immediately the oocyte (egg) was fertilized and terminated when the embryo hatched from the chorion membranous wall. The young larva emerged from the embryonic membrane at 24.46 hrs with vigorous lashing of the caudal region against the chorion membrane. The average weight and length of the yolk larvae were 0.005g and 0.43 cm respectively. The percentage fertilization and hatchability rates were 82.50 and 65.10% respectively. The experiment revealed that Heterobranchus longifilis could be a good aquaculture species.

COMPARATIVE EMBRYONIC AND LARVAL DEVELOPMENTAL RESPONSES OF AN ESTUARINE SHRIMP (PALAEMONETES PUGIO) TO THE JUVENILE HORMONE AGONIST, FENOXYCARB.

EPA Science Inventory

Grass shrimp (Palaemonetes pugio) were reared separately through both embryonic and total larval development during exposure to fenoxycarb at measured concentrations of <2.2 to 888 ug L-1. A fenoxycarb concentration of 888 ug L-1significantly (p<0.05) inhibited embryonic developm...

The sulphation of chondroitin sulphate in embryonic chicken cartilage

PubMed Central

Robinson, H. C.

1969-01-01

1. Whole tissue preparations and subcellular fractions from embryonic chicken cartilage were used to measure the rate of incorporation of inorganic sulphate into chondroitin sulphate in vitro. 2. In cartilage from 14-day-old embryos, [35S]sulphate is incorporated to an equal extent into chondroitin 4-sulphate and chondroitin 6-sulphate at a rate of 1·5nmoles of sulphate/hr./mg. dry wt. of cartilage. 3. Microsomal and soluble enzyme preparations from embryonic cartilage catalyse the transfer of sulphate from adenosine 3′-phosphate 5′-sulphatophosphate into both chondroitin 4-sulphate and chondroitin 6-sulphate. 4. The effects of pH, ionic strength, adenosine 3′-phosphate 5′-sulphatophosphate concentration and acceptor chondroitin sulphate concentration on the soluble sulphotransferase activity were examined. These factors all influence the activity of the sulphotransferase, and pH and incubation time also influence the percentage of chondroitin 4-sulphate formed. PMID:5807213

Developmental plasticity of mitochondrial function in American alligators, Alligator mississippiensis

PubMed Central

Crossley, Janna; Elsey, Ruth M.; Dzialowski, Edward M.; Shiels, Holly A.; Crossley, Dane A.

2016-01-01

The effect of hypoxia on cellular metabolism is well documented in adult vertebrates, but information is entirely lacking for embryonic organisms. The effect of hypoxia on embryonic physiology is particularly interesting, as metabolic responses during development may have life-long consequences, due to developmental plasticity. To this end, we investigated the effects of chronic developmental hypoxia on cardiac mitochondrial function in embryonic and juvenile American alligators (Alligator mississippiensis). Alligator eggs were incubated in 21% or 10% oxygen from 20 to 90% of embryonic development. Embryos were either harvested at 90% development or allowed to hatch and then reared in 21% oxygen for 3 yr. Ventricular mitochondria were isolated from embryonic/juvenile alligator hearts. Mitochondrial respiration and enzymatic activities of electron transport chain complexes were measured with a microrespirometer and spectrophotometer, respectively. Developmental hypoxia induced growth restriction and increased relative heart mass, and this phenotype persisted into juvenile life. Embryonic mitochondrial function was not affected by developmental hypoxia, but at the juvenile life stage, animals from hypoxic incubations had lower levels of Leak respiration and higher respiratory control ratios, which is indicative of enhanced mitochondrial efficiency. Our results suggest developmental hypoxia can have life-long consequences for alligator morphology and metabolic function. Further investigations are necessary to reveal the adaptive significance of the enhanced mitochondrial efficiency in the hypoxic phenotype. PMID:27707718

Environmental and epigenetic effects upon preimplantation embryo metabolism and development

PubMed Central

Chason, Rebecca J; Csokmay, John; Segars, James H.; DeCherney, Alan H.; Armant, D. Randall

2011-01-01

In vitro fertilization has provided a unique window into the metabolic processes that drive embryonic growth and development from a fertilized ovum to a competent blastocyst. Post-fertilization development is dependent upon a dramatic reshuffling of the parental genomes during meiosis, as well as epigenetic changes that provide a new and autonomous set of instructions to guide cellular differentiation both in the embryo and beyond. While early literature focused simply on the substrates and culture conditions required for progress through embryonic development, more recent insights lead us to suggest that the surrounding environment can alter the epigenome, which can, in turn, impact embryonic metabolism and developmental competence. PMID:21741268

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.

Identification of Estrogen Target Genes during Zebrafish Embryonic Development through Transcriptomic Analysis

EPA Science Inventory

Estrogen signaling is important for vertebrate embryonic development. Here we have used zebrafish (Danio rerio) as a vertebrate model to analyze estrogen signaling during development. Zebrafish embryos were exposed to 1 μM 17β-estradiol (E2) or vehicle from 3 hours to 4 days post...

Observations on germ band development in the cellar spider Pholcus phalangioides.

PubMed

Turetzek, Natascha; Prpic, Nikola-Michael

2016-11-01

Most recent studies of spider embryonic development have focused on representatives of the species-rich group of entelegyne spiders (over 80 % of all extant species). Embryogenesis in the smaller spider groups, however, is less well studied. Here, we describe the development of the germ band in the spider species Pholcus phalangioides, a representative of the haplogyne spiders that are phylogenetically the sister group of the entelegyne spiders. We show that the transition from radially symmetric embryonic anlage to the bilaterally symmetric germ band involves the accumulation of cells in the centre of the embryonic anlage (primary thickening). These cells then disperse all across the embryonic anlage. A secondary thickening of cells then appears in the centre of the embryonic anlage, and this thickening expands and forms the segment addition zone. We also confirm that the major part of the opisthosoma initially develops as a tube shaped structure, and its segments are then sequentially folded down on the yolk during inversion. This special mode of opisthosoma formation has not been reported for entelegyne spiders, but a more comprehensive sampling of this diverse group is necessary to decide whether this peculiarity is indeed lacking in the entelegyne spiders.

The Phosphatase PTP-PEST/PTPN12 Regulates Endothelial Cell Migration and Adhesion, but Not Permeability, and Controls Vascular Development and Embryonic Viability*

PubMed Central

Souza, Cleiton Martins; Davidson, Dominique; Rhee, Inmoo; Gratton, Jean-Philippe; Davis, Elaine C.; Veillette, André

2012-01-01

Protein-tyrosine phosphatase (PTP)-PEST (PTPN12) is ubiquitously expressed. It is essential for normal embryonic development and embryonic viability in mice. Herein we addressed the involvement of PTP-PEST in endothelial cell functions using a combination of genetic and biochemical approaches. By generating primary endothelial cells from an inducible PTP-PEST-deficient mouse, we found that PTP-PEST is not needed for endothelial cell differentiation and proliferation or for the control of endothelial cell permeability. Nevertheless, it is required for integrin-mediated adhesion and migration of endothelial cells. PTP-PEST-deficient endothelial cells displayed increased tyrosine phosphorylation of Cas, paxillin, and Pyk2, which were previously also implicated in integrin functions. By eliminating PTP-PEST in endothelial cells in vivo, we obtained evidence that expression of PTP-PEST in endothelial cells is required for normal vascular development and embryonic viability. Therefore, PTP-PEST is a key regulator of integrin-mediated functions in endothelial cells seemingly through its capacity to control Cas, paxillin, and Pyk2. This function explains at least in part the essential role of PTP-PEST in embryonic development and viability. PMID:23105101

Generation of embryos directly from embryonic stem cells by tetraploid embryo complementation reveals a role for GATA factors in organogenesis.

PubMed

Duncan, S A

2005-12-01

Gene targeting in ES (embryonic stem) cells has been used extensively to study the role of proteins during embryonic development. In the traditional procedure, this requires the generation of chimaeric mice by introducing ES cells into blastocysts and allowing them to develop to term. Once chimaeric mice are produced, they are bred into a recipient mouse strain to establish germline transmission of the allele of interest. Although this approach has been used very successfully, the breeding cycles involved are time consuming. In addition, genes that are essential for organogenesis often have roles in the formation of extra-embryonic tissues that are essential for early stages of post-implantation development. For example, mice lacking the GATA transcription factors, GATA4 or GATA6, arrest during gastrulation due to an essential role for these factors in differentiation of extra-embryonic endoderm. This lethality has frustrated the study of these factors during the development of organs such as the liver and heart. Extraembryonic defects can, however, be circumvented by generating clonal mouse embryos directly from ES cells by tetraploid complementation. Here, we describe the usefulness and efficacy of this approach using GATA factors as an example.

Serial block face-scanning electron microscopy: a tool for studying embryonic development at the cell-matrix interface.

PubMed

Starborg, Tobias; Kadler, Karl E

2015-03-01

Studies of gene regulation, signaling pathways, and stem cell biology are contributing greatly to our understanding of early embryonic vertebrate development. However, much less is known about the events during the latter half of embryonic development, when tissues comprising mostly extracellular matrix (ECM) are formed. The matrix extends far beyond the boundaries of individual cells and is refractory to study by conventional biochemical and molecular techniques; thus major gaps exist in our knowledge of the formation and three-dimensional (3D) organization of the dense tissues that form the bulk of adult vertebrates. Serial block face-scanning electron microscopy (SBF-SEM) has the ability to image volumes of tissue containing numerous cells at a resolution sufficient to study the organization of the ECM. Furthermore, whereas light microscopy was once relatively straightforward and electron microscopy was performed in specialist laboratories, the tables are turned; SBF-SEM is relatively straightforward and is becoming routine in high-end resolution studies of embryonic structures in vivo. In this review, we discuss the emergence of SBF-SEM as a tool for studying embryonic vertebrate development. © 2015 Wiley Periodicals, Inc.

Observation of human embryonic behavior in vitro by high-resolution time-lapse cinematography.

PubMed

Iwata, Kyoko; Mio, Yasuyuki

2016-07-01

Assisted reproductive technology (ART) has yielded vast amounts of information and knowledge on human embryonic development in vitro; however, still images provide limited data on dynamic changes in the developing embryos. Using our high-resolution time-lapse cinematography (hR-TLC) system, we were able to describe normal human embryonic development continuously from the fertilization process to the hatched blastocyst stage in detail. Our hR-TLC observation also showed the embryonic abnormality of a third polar body (PB)-like substance likely containing a small pronucleus being extruded and resulting in single-pronucleus (1PN) formation, while our molecular biological investigations suggested the possibility that some 1PN embryos could be diploid, carrying both maternal and paternal genomes. Furthermore, in some embryos the extruded third PB-like substance was eventually re-absorbed into the ooplasm resulting in the formation of an uneven-sized, two-PN zygote. In addition, other hR-TLC observations showed that cytokinetic failure was correlated with equal-sized, multi-nucleated blastomeres that were also observed in the embryo showing early initiation of compaction. Assessment combining our hR-TLC with molecular biological techniques enables a better understanding of embryonic development and potential improvements in ART outcomes.

Sensitivity of human embryonic stem cells to different conditions during cryopreservation.

PubMed

Xu, Yanqing; Zhang, Liang; Xu, Jiandong; Wei, Yuping; Xu, Xia

2015-12-01

Low cell recovery rate of human embryonic stem cells (hESCs) resulting from cryopreservation damages leads to the difficulty in their successful commercialization of clinical applications. Hence in this study, sensitivity of human embryonic stem cells (hESCs) to different cooling rates, ice seeding and cryoprotective agent (CPA) types was compared and cell viability and recovery after cryopreservation under different cooling conditions were assessed. Both extracellular and intracellular ice formation were observed. Reactive oxidative species (ROS) accumulation of hESCs was determined. Cryopreservation of hESCs at 1 °C/min with the ice seeding and at the theoretically predicted optimal cooling rate (TPOCR) led to lower level of intracellular ROS, and prevented irregular and big ice clump formation compared with cryopreservation at 1 °C/min. This strategy further resulted in a significant increase in the hESC recovery when glycerol and 1,2-propanediol were used as the CPAs, but no increase for Me2SO. hESCs after cryopreservation under all the tested conditions still maintained their pluripotency. Our results provide guidance for improving the hESC cryopreservation recovery through the combination of CPA type, cooling rate and ice seeding. Copyright © 2015 Elsevier Inc. All rights reserved.

Prolactin modulates luteal activity in the short-nosed fruit bat, Cynopterus sphinx during delayed embryonic development.

PubMed

Anuradha; Krishna, Amitabh

2017-07-01

The aim of this study was to evaluate the role of prolactin as a modulator of luteal steroidogenesis during the period of delayed embryonic development in Cynopterus sphinx. A marked decline in circulating prolactin levels was noted during the months of November through December coinciding with the period of decreased serum progesterone and delayed embryonic development. The seasonal changes in serum prolactin levels correlated positively with circulating progesterone (P) level, but inversely with circulating melatonin level during first pregnancy showing delayed development in Cynopterus sphinx. The results also showed decreased expression of prolactin receptor-short form (PRL-RS) both in the corpus luteum and in the utero-embryonic unit during the period of delayed embryonic development. Bats treated in vivo with prolactin during the period of delayed development showed significant increase in serum progesterone and estradiol levels together with significant increase in the expression of PRL-RS, luteinizing hormone receptor (LH-R), steroidogenic acute receptor protein (STAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) in the ovary. Prolactin stimulated ovarian angiogenesis (vascular endothelial growth factor) and cell survival (B-cell lymphoma 2) in vivo. Significant increases in ovarian progesterone production and the expression of prolactin-receptor, LH-R, STAR and 3β-HSD proteins were noted following the exposure of LH or prolactin in vitro during the delayed period. In conclusion, short-day associated increased melatonin level may be responsible for decreased prolactin release during November-December. The decline in prolactin level might play a role in suppressing P and estradiol-17β (E2) estradiol levels thereby causing delayed embryonic development in C. sphinx. Copyright © 2017 Elsevier Inc. All rights reserved.

Novel Method To Differentiate Human Embryonic Stem Cells Into Dopaminergic Nerve Cells | NCI Technology Transfer Center | TTC

Cancer.gov

The National Institute on Drug Abuse's Development and Plasticity Section is seeking statements of capability or interest from parties interested in licensing opportunities to further develop, evaluate, or commercialize novel methods to differentiate human embryonic stem cells into dopaminergic nerve cells. The invention described here is a novel method of differentiating human embryonic stem cells (hESCs) into dopaminergic nerve cells, which is preferable to the currently available dopaminergic differentiation techniques.

Transgenerational effects from early developmental exposures to bisphenol A or 17α-ethinylestradiol in medaka, Oryzias latipes

USGS Publications Warehouse

Bhandari, Ramji K.; vom Saal, Frederick S.; Tillitt, Donald E.

2015-01-01

The transgenerational consequences of environmental contaminant exposures of aquatic vertebrates have the potential for broad ecological impacts, yet are largely uninvestigated. Bisphenol A (BPA) and 17α-ethinylestradiol (EE2) are two ubiquitous estrogenic chemicals present in aquatic environments throughout the United States and many other countries. Aquatic organisms, including fish, are exposed to varying concentrations of these chemicals at various stages of their life history. Here, we tested the ability of embryonic exposure to BPA or EE2 to cause adverse health outcomes at later life stages and transgenerational abnormalities in medaka fish. Exposures of F0 medaka to either BPA (100 μg/L) or EE2 (0.05 μg/L) during the first 7 days of embryonic development, when germ cells are differentiating, did not cause any apparent phenotypic abnormalities in F0 or F1 generations, but led to a significant reduction in the fertilization rate in offspring two generations later (F2) as well as a reduction of embryo survival in offspring three generations later (F3). Our present observations suggest that BPA or EE2 exposure during development induces transgenerational phenotypes of reproductive impairment and compromised embryonic survival in fish of subsequent generations. These adverse outcomes may have negative impacts on populations of fish inhabiting contaminated aquatic environments.

Effects of heavy ion radiation on the brain vascular system and embryonic development

NASA Technical Reports Server (NTRS)

Yang, T. C.; Tobias, C. A.

1984-01-01

The present investigation is concerned with the effects of heavy-ion radiation on the vascular system and the embryonic development, taking into account the results of experiments with neonatal rats and mouse embryos. It is found that heavy ions can be highly effective in producing brain hemorrhages and in causing body deformities. Attention is given to aspects of methodology, the induction of brain hemorrhages by X-rays and heavy ions, and the effect of iron particles on embryonic development. Reported results suggest that high linear energy transfer (LET) heavy ions can be very effective in producing developmental abnormalities.

Identification and functional analysis of long non-coding RNAs in human and mouse early embryos based on single-cell transcriptome data

PubMed Central

Qiu, Jia-jun; Ren, Zhao-rui; Yan, Jing-bin

2016-01-01

Epigenetics regulations have an important role in fertilization and proper embryonic development, and several human diseases are associated with epigenetic modification disorders, such as Rett syndrome, Beckwith-Wiedemann syndrome and Angelman syndrome. However, the dynamics and functions of long non-coding RNAs (lncRNAs), one type of epigenetic regulators, in human pre-implantation development have not yet been demonstrated. In this study, a comprehensive analysis of human and mouse early-stage embryonic lncRNAs was performed based on public single-cell RNA sequencing data. Expression profile analysis revealed that lncRNAs are expressed in a developmental stage–specific manner during human early-stage embryonic development, whereas a more temporal-specific expression pattern was identified in mouse embryos. Weighted gene co-expression network analysis suggested that lncRNAs involved in human early-stage embryonic development are associated with several important functions and processes, such as oocyte maturation, zygotic genome activation and mitochondrial functions. We also found that the network of lncRNAs involved in zygotic genome activation was highly preservative between human and mouse embryos, whereas in other stages no strong correlation between human and mouse embryo was observed. This study provides insight into the molecular mechanism underlying lncRNA involvement in human pre-implantation embryonic development. PMID:27542205

Platelets regulate lymphatic vascular development through CLEC-2-SLP-76 signaling.

PubMed

Bertozzi, Cara C; Schmaier, Alec A; Mericko, Patricia; Hess, Paul R; Zou, Zhiying; Chen, Mei; Chen, Chiu-Yu; Xu, Bin; Lu, Min-min; Zhou, Diane; Sebzda, Eric; Santore, Matthew T; Merianos, Demetri J; Stadtfeld, Matthias; Flake, Alan W; Graf, Thomas; Skoda, Radek; Maltzman, Jonathan S; Koretzky, Gary A; Kahn, Mark L

2010-07-29

Although platelets appear by embryonic day 10.5 in the developing mouse, an embryonic role for these cells has not been identified. The SYK-SLP-76 signaling pathway is required in blood cells to regulate embryonic blood-lymphatic vascular separation, but the cell type and molecular mechanism underlying this regulatory pathway are not known. In the present study we demonstrate that platelets regulate lymphatic vascular development by directly interacting with lymphatic endothelial cells through C-type lectin-like receptor 2 (CLEC-2) receptors. PODOPLANIN (PDPN), a transmembrane protein expressed on the surface of lymphatic endothelial cells, is required in nonhematopoietic cells for blood-lymphatic separation. Genetic loss of the PDPN receptor CLEC-2 ablates PDPN binding by platelets and confers embryonic lymphatic vascular defects like those seen in animals lacking PDPN or SLP-76. Platelet factor 4-Cre-mediated deletion of Slp-76 is sufficient to confer lymphatic vascular defects, identifying platelets as the cell type in which SLP-76 signaling is required to regulate lymphatic vascular development. Consistent with these genetic findings, we observe SLP-76-dependent platelet aggregate formation on the surface of lymphatic endothelial cells in vivo and ex vivo. These studies identify a nonhemostatic pathway in which platelet CLEC-2 receptors bind lymphatic endothelial PDPN and activate SLP-76 signaling to regulate embryonic vascular development.

Correlation of Versican Expression, Accumulation, and Degradation during Embryonic Development by Quantitative Immunohistochemistry

PubMed Central

Snyder, Jessica M.; Washington, Ida M.; Birkland, Timothy; Chang, Mary Y.; Frevert, Charles W.

2015-01-01

Versican, a chondroitin sulfate proteoglycan, is important in embryonic development, and disruption of the versican gene is embryonically lethal in the mouse. Although several studies show that versican is increased in various organs during development, a focused quantitative study on versican expression and distribution during lung and central nervous system development in the mouse has not previously been performed. We tracked changes in versican (Vcan) gene expression and in the accumulation and degradation of versican. Vcan expression and quantitative immunohistochemistry performed from embryonic day (E) 11.5 to E15.5 showed peak Vcan expression at E13.5 in the lungs and brain. Quantitative mRNA analysis and versican immunohistochemistry showed differences in the expression of the versican isoforms in the embryonic lung and head. The expression of Vcan mRNA and accumulation of versican in tissues was complementary. Immunohistochemistry demonstrated co-localization of versican accumulation and degradation, suggesting distinct roles of versican deposition and degradation in embryogenesis. Very little versican mRNA or protein was found in the lungs of 12- to 16-week-old mice but versican accumulation was significantly increased in mice with Pseudomonas aeruginosa lung infection. These data suggest that versican plays an important role in fundamental, overlapping cellular processes in lung development and infection. PMID:26385570

Embryonic kidney function in a chronic renal failure model in rodents.

PubMed

Fujimoto, Eisuke; Yamanaka, Shuichiro; Kurihara, Sho; Tajiri, Susumu; Izuhara, Luna; Katsuoka, Yuichi; Yokote, Shinya; Matsumoto, Kei; Kobayashi, Eiji; Okano, Hirotaka James; Chikaraishi, Tatsuya; Yokoo, Takashi

2017-08-01

Rapid advancements have been made in alternative treatments for renal diseases. Our goal for renal regeneration is to establish a kidney graft derived from human embryonic tissues. In this study, we investigated the effects of host renal failure on the structure and activity of transplanted embryonic kidney and bladder, and found that diuretics effectively induced urine production in the transplanted kidney. Uremic conditions were reproduced using a 5/6 renal infarction rat model. An embryonic kidney plus bladder (embryonic day 15) was isolated from a pregnant Lewis rat and transplanted into the para-aortic area of a 5/6 renal-infarcted Lewis rat. Following growth, the embryonic bladder was successfully anastomosed to the host ureter. We assessed graft function in terms of survival rates and found no differences between normal (n = 5) and renal failure (n = 8) groups (median survival: 70.5 vs 74.5 h; p = 0.331) in terms of survival, indicating that the grafts prolonged rat survival, even under renal failure conditions. Furosemide (n = 9) significantly increased urine volume compared with saline-treated controls (n = 7; p < 0.05), confirming that the grafts were functional. We also demonstrated the possibilities of an in vivo imaging system for determining the viability of transplanted embryonic kidney with bladder. The results of this study demonstrate that transplanted embryonic kidney and bladder can grow and function effectively, even under uremic conditions.

Delayed development in Fischer's pygmy fruit bat, Haplonycteris fischeri, in the Philippines.

PubMed

Heideman, P D

1989-03-01

A long delay in post-implantation embryonic development was detected in Fischer's pygmy fruit bats (palaeotropical fruit bats of the suborder Megachiroptera), the first time such a delay has been demonstrated outside the bat suborder Microchiroptera. Samples of bats were obtained from the Philippines over 5 years, and reproductive tracts were preserved and examined using standard histological techniques. Most parous female pygmy bats were impregnated in June, within a few weeks of parturition, and the embryos underwent superficial implantation at the anterior end of the uterus contralateral to the previously gravid uterus. Shortly thereafter, the rate of embryonic growth slowed tremendously for up to 8 months. During the period of delay, the mean length of the embryoblast increased only from 280 microns to 520 microns. In March of the following year, the developmental rate increased, and the embryos completed development in the next 3 months. The 8-month delay gives these bats a gestation period of 11.5 months, the longest known in bats. Most nulliparous females become pregnant at an age of 3-5 months, and their embryos entered a similar delay that terminated in March or April, after 2-6 months of delay. Males showed signs of fertility throughout the entire year, but testis volume was highest during May, June and July, at about the time when most females become receptive.

Past primary sex-ratio estimates of 4 populations of Loggerhead sea turtle based on TSP durations.

NASA Astrophysics Data System (ADS)

Monsinjon, Jonathan; Kaska, Yakup; Tucker, Tony; LeBlanc, Anne Marie; Williams, Kristina; Rostal, David; Girondot, Marc

2016-04-01

Ectothermic species are supposed to be strongly affected by climate change and particularly those that exhibit temperature-dependent sex-determination (TSD). Actually, predicting the embryonic response of such organism to incubation-temperature variations in natural conditions remains challenging. In order to assess the vulnerability of sea turtles, primary sex-ratio estimates should be produced at pertinent ecological time and spatial scales. Although information on this important demographic parameter is one of the priorities for conservation purpose, accurate methodology to produce such an estimate is still lacking. The most commonly used method invocates incubation duration as a proxy for sex-ratio. This method is inappropriate because temperature influences incubation duration during all development whereas sex is influenced by temperature during only part of development. The thermosensitive period of development for sex determination (TSP) lies in the middle third of development. A model of embryonic growth must be used to define precisely the position of the TSP at non-constant incubation temperatures. The thermal reaction norm for embryonic growth rate have been estimated for 4 distinct populations of the globally distributed and threatened marine turtle Caretta caretta. A thermal reaction norm describes the pattern of phenotypic expression of a single genotype across a range of temperatures. Moreover, incubation temperatures have been reconstructed for the last 35 years using a multi-correlative model with climate temperature. After development of embryos have been modelled, we estimated the primary sex-ratio based on the duration of the TSP. Our results suggests that Loggerhead sea turtles nesting phenology is linked with the period within which both sexes can be produced in variable proportions. Several hypotheses will be discussed to explain why Caretta caretta could be more resilient to climate change than generally thought for sex determination.

Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds.

PubMed

Gorim, Linda; Asch, Folkard

2017-05-24

Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition.

Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds

PubMed Central

Gorim, Linda; Asch, Folkard

2017-01-01

Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition. PMID:28538658

Exposure to Endocrine Disruptor Induces Transgenerational Epigenetic Deregulation of MicroRNAs in Primordial Germ Cells

PubMed Central

Brieño-Enríquez, Miguel A.; García-López, Jesús; Cárdenas, David B.; Guibert, Sylvain; Cleroux, Elouan; Děd, Lukas; Hourcade, Juan de Dios; Pěknicová, Jana; Weber, Michael; del Mazo, Jesús

2015-01-01

In mammals, germ cell differentiation is initiated in the Primordial Germ Cells (PGCs) during fetal development. Prenatal exposure to environmental toxicants such as endocrine disruptors may alter PGC differentiation, development of the male germline and induce transgenerational epigenetic disorders. The anti-androgenic compound vinclozolin represents a paradigmatic example of molecule causing transgenerational effects on germ cells. We performed prenatal exposure to vinclozolin in mice and analyzed the phenotypic and molecular changes in three successive generations. A reduction in the number of embryonic PGCs and increased rate of apoptotic cells along with decrease of fertility rate in adult males were observed in F1 to F3 generations. Blimp1 is a crucial regulator of PGC differentiation. We show that prenatal exposure to vinclozolin deregulates specific microRNAs in PGCs, such as miR-23b and miR-21, inducing disequilibrium in the Lin28/let-7/Blimp1 pathway in three successive generations of males. As determined by global maps of cytosine methylation, we found no evidence for prominent changes in DNA methylation in PGCs or mature sperm. Our data suggest that embryonic exposure to environmental endocrine disruptors induces transgenerational epigenetic deregulation of expression of microRNAs affecting key regulatory pathways of germ cells differentiation. PMID:25897752

Nest morphology and body size of Ross' Geese and Lesser Snow Geese

USGS Publications Warehouse

McCracken, K.G.; Afton, A.D.; Alisauskas, R.T.

1997-01-01

Arctic-nesting geese build large, insulated nests to protect developing embryos from cold ambient temperatures. Ross' Geese (Chen rossii) are about two-thirds the mass of Lesser Snow Geese (C. caerulescens caerulescens), have higher mass-specific metabolic rate, and maintain lower nest attentiveness, yet they hatch goslings with more functionally mature gizzards and more protein for their size than do Lesser Snow Geese. We compared nest size (a reflection of nest insulation) in four distinct habitats in a mixed breeding colony of Ross' Geese and Lesser Snow Geese at Karrak Lake, Northwest Territories, Canada. After adjusting measurements for nest-specific egg size and clutch size, we found that overall nest morphology differed between species and among habitats. Nest size increased progressively among heath, rock, mixed, and moss habitats. When nesting materials were not limiting, nests were smaller in habitats that provided cover from wind and precipitation than in habitats that did not provide cover. Ross' Geese constructed relatively larger, more insulated nests than did Lesser Snow Geese, which may hasten embryonic development, minimize energy expenditure during incubation, and minimize embryonic cooling during recesses. We suggest that relative differences in nest morphology reflect greater selection for Ross' Geese to improve nest insulation because of their smaller size (adults and embryos), higher mass-specific metabolic rate, and lower incubation constancy.

Functional video-based analysis of 3D cardiac structures generated from human embryonic stem cells.

PubMed

Nitsch, Scarlett; Braun, Florian; Ritter, Sylvia; Scholz, Michael; Schroeder, Insa S

2018-05-01

Human embryonic stem cells (hESCs) differentiated into cardiomyocytes (CM) often develop into complex 3D structures that are composed of various cardiac cell types. Conventional methods to study the electrophysiology of cardiac cells are patch clamp and microelectrode array (MEAs) analyses. However, these methods are not suitable to investigate the contractile features of 3D cardiac clusters that detach from the surface of the culture dishes during differentiation. To overcome this problem, we developed a video-based motion detection software relying on the optical flow by Farnebäck that we call cBRA (cardiac beat rate analyzer). The beating characteristics of the differentiated cardiac clusters were calculated based on the local displacement between two subsequent images. Two differentiation protocols, which profoundly differ in the morphology of cardiac clusters generated and in the expression of cardiac markers, were used and the resulting CM were characterized. Despite these differences, beat rates and beating variabilities could be reliably determined using cBRA. Likewise, stimulation of β-adrenoreceptors by isoproterenol could easily be identified in the hESC-derived CM. Since even subtle changes in the beating features are detectable, this method is suitable for high throughput cardiotoxicity screenings. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

In utero imaging of mouse embryonic development with optical coherence tomography

NASA Astrophysics Data System (ADS)

Syed, Saba H.; Dickinson, Mary E.; Larin, Kirill V.; Larina, Irina V.

2011-03-01

Studying progression of congenital diseases in animal models can greatly benefit from live embryonic imaging Mouse have long served as a model of mammalian embryonic developmental processes, however, due to intra-uterine nature of mammalian development live imaging is challenging. In this report we present results on live mouse embryonic imaging in utero with Optical Coherence Tomography. Embryos from 12.5 through 17.5 days post-coitus (dpc) were studied through the uterine wall. In longitudinal studies, same embryos were imaged at developmental stages 13.5, 15.5 and 17.5 dpc. This study suggests that OCT can serve as a powerful tool for live mouse embryo imaging. Potentially this technique can contribute to our understanding developmental abnormalities associated with mutations, toxic drugs.

Nitric Oxide Synthase-3 Promotes Embryonic Development of Atrioventricular Valves

PubMed Central

Liu, Yin; Lu, Xiangru; Xiang, Fu-Li; Lu, Man; Feng, Qingping

2013-01-01

Nitric oxide synthase-3 (NOS3) has recently been shown to promote endothelial-to-mesenchymal transition (EndMT) in the developing atrioventricular (AV) canal. The present study was aimed to investigate the role of NOS3 in embryonic development of AV valves. We hypothesized that NOS3 promotes embryonic development of AV valves via EndMT. To test this hypothesis, morphological and functional analysis of AV valves were performed in wild-type (WT) and NOS3−/− mice at postnatal day 0. Our data show that the overall size and length of mitral and tricuspid valves were decreased in NOS3−/− compared with WT mice. Echocardiographic assessment showed significant regurgitation of mitral and tricuspid valves during systole in NOS3−/− mice. These phenotypes were all rescued by cardiac specific NOS3 overexpression. To assess EndMT, immunostaining of Snail1 was performed in the embryonic heart. Both total mesenchymal and Snail1+ cells in the AV cushion were decreased in NOS3−/− compared with WT mice at E10.5 and E12.5, which was completely restored by cardiac specific NOS3 overexpression. In cultured embryonic hearts, NOS3 promoted transforming growth factor (TGFβ), bone morphogenetic protein (BMP2) and Snail1expression through cGMP. Furthermore, mesenchymal cell formation and migration from cultured AV cushion explants were decreased in the NOS3−/− compared with WT mice. We conclude that NOS3 promotes AV valve formation during embryonic heart development and deficiency in NOS3 results in AV valve insufficiency. PMID:24204893

Engineering human cell spheroids to model embryonic tissue fusion in vitro.

EPA Science Inventory

Epithelial-mesenchymal interactions drive embryonic fusion events during development and upon perturbation can result in birth defects. Cleft palate and neural tube defects can result from genetic defects or environmental exposures during development, yet very little is known abo...

Exploitation of genetic and physiological determinants of embryonic resistance to elevated temperature to improve embryonic survival in dairy cattle during heat stress.

PubMed

Hansen, P J

2007-09-01

Heat stress causes large reductions in fertility in lactating dairy cows. The magnitude and geographical extent of this problem is increasing because improvements in milk yield have made it more difficult for cows to regulate body temperature during warm weather. There have been efforts to improve fertility during heat stress by exploiting determinants of oocyte and embryonic responses to elevated temperature. Among these determinants are genotype, stage of development, and presence of cytoprotective molecules in the reproductive tract. One effective strategy for increasing pregnancy rate during heat stress is to use embryo transfer to bypass effects of elevated temperature on the oocyte and early embryo. Pregnancy success to embryo transfer in the summer can be further improved by exposure of embryos to insulin-like growth factor-I during culture before transfer. Among the cytoprotective molecules that have been examined for enhancing fertility during heat stress are bovine somatotropin and various antioxidants. To date, an effective method for delivery of these molecules to increase fertility during heat stress has not been identified. Genes in cattle exist for regulation of body temperature and for cellular resistance to elevated temperature. Although largely unidentified, the existence of these genes offers the possibility for their incorporation into dairy breeds through crossbreeding or on an individual-gene basis. In summary, physiological or genetic manipulation of the cow to improve embryonic resistance to elevated temperature is a promising approach for enhancing fertility of lactating dairy cows.

Single nucleotide polymorphisms in candidate genes associated with fertilizing ability of sperm and subsequent embryonic development in cattle

USDA-ARS?s Scientific Manuscript database

Fertilization and development of the preimplantation embryo is under genetic control. The goal of the current study was to test 434 single nucleotide polymorphisms (SNPs) for association with genetic variation in fertilization and early embryonic development. The approach was to produce embryos from...

Maternal transfer of methimazole and effects on thyroid hormone availability in embryonic tissues.

PubMed

Van Herck, Stijn L J; Geysens, Stijn; Bald, Edward; Chwatko, Grazyna; Delezie, Evelyne; Dianati, Elham; Ahmed, R G; Darras, Veerle M

2013-07-01

Methimazole (MMI) is an anti-thyroid drug used in the treatment of chronic hyperthyroidism. There is, however, some debate about its use during pregnancy as MMI is known to cross the mammalian placenta and reach the developing foetus. A similar problem occurs in birds, where MMI is deposited in the egg and taken up by the developing embryo. To investigate whether maternally derived MMI can have detrimental effects on embryonic development, we treated laying hens with MMI (0.03% in drinking water) and measured total and reduced MMI contents in the tissues of hens and embryos at different stages of development. In hens, MMI was selectively increased in the thyroid gland, while its levels in the liver and especially brain remained relatively low. Long-term MMI treatment induced a pronounced goitre with a decrease in thyroxine (T₄) content but an increase in thyroidal 3,5,3'-triiodothyronine (T₃) content. This resulted in normal T₃ levels in tissues except in the brain. In chicken embryos, MMI levels were similar in the liver and brain. They gradually decreased during development but always remained above those in the corresponding maternal tissues. Contrary to the situation in hens, T₄ availability was only moderately affected in embryos. Peripheral T₃ levels were reduced in 14-day-old embryos but normal in 18-day-old embryos, while brain T₃ content was decreased at all embryonic stages tested. We conclude that all embryonic tissues are exposed to relatively high doses of MMI and its oxidised metabolites. The effect of maternal MMI treatment on embryonic thyroid hormone availability is most pronounced for brain T₃ content, which is reduced throughout the embryonic development period.

Ablation of cdk4 and cdk6 affects proliferation of basal progenitor cells in the developing dorsal and ventral forebrain.

PubMed

Grison, Alice; Gaiser, Carine; Bieder, Andrea; Baranek, Constanze; Atanasoski, Suzana

2018-03-23

Little is known about the molecular players driving proliferation of neural progenitor cells (NPCs) during embryonic mouse development. Here, we demonstrate that proliferation of NPCs in the developing forebrain depends on a particular combination of cell cycle regulators. We have analyzed the requirements for members of the cyclin-dependent kinase (cdk) family using cdk-deficient mice. In the absence of either cdk4 or cdk6, which are both regulators of the G1 phase of the cell cycle, we found no significant effects on the proliferation rate of cortical progenitor cells. However, concomitant loss of cdk4 and cdk6 led to a drastic decrease in the proliferation rate of NPCs, specifically the basal progenitor cells of both the dorsal and ventral forebrain at embryonic day 13.5 (E13.5). Moreover, basal progenitors in the forebrain of Cdk4;Cdk6 double mutant mice exhibited altered cell cycle characteristics. Cdk4;cdk6 deficiency led to an increase in cell cycle length and cell cycle exit of mutant basal progenitor cells in comparison to controls. In contrast, concomitant ablation of cdk2 and cdk6 had no effect on the proliferation of NCPs. Together, our data demonstrate that the expansion of the basal progenitor pool in the developing telencephalon is dependent on the presence of distinct combinations of cdk molecules. Our results provide further evidence for differences in the regulation of proliferation between apical and basal progenitors during cortical development. © 2018 Wiley Periodicals, Inc. Develop Neurobiol, 2018. © 2018 Wiley Periodicals, Inc.

Oxygen uptake by embryos and ovigerous females of two intertidal crabs, Heterozius rotundifrons (Belliidae) and Cyclograpsus lavauxi (Grapsidae): scaling and the metabolic costs of reproduction.

PubMed

Taylor, H H; Leelapiyanart, N

2001-03-01

Heterozius rotundifrons and Cyclograpsus lavauxi are crabs of similar size, whose intertidal habitats overlap. They differ in the number and size of their eggs. A 2 g ovigerous H. rotundifrons incubates 675 large yolky eggs (mean single-egg mass 269 microg; egg clutch 9.15 % of mass of female crab; increasing to 435 microg and 13.4 % at hatching). The egg clutch of a 2 g C. lavauxi is larger (15.4 % of crab mass increasing to 18.9 % at hatching) and contains more numerous (28 000), smaller (10.9 microg increasing to 20.3 microg) eggs. The longer development time of the larger eggs (194 days versus 56 days at 15 degrees C) results from a delayed increase in metabolic rate (diapause) and not metabolic scaling. On the basis of the total mass of single eggs, the mass-specific metabolic rates of early embryonic stages of H. rotundifrons (0.72 micromol g(-1 )h(-1) for the blastula stage at 15 degrees C) and C. lavauxi (1.13 micromol g(-1 )h(-1)) were similar to those of the adult female crabs (0.70 micromol g(-1 )h(-1) for H. rotundifrons and 0.91 micromol g(-1 )h(-1) for C. lavauxi) and increased 13- and 10-fold, respectively, by the time of hatching. Thus, early embryonic metabolic rates were much lower than expected from their mass, but the metabolic rates of pre-hatching embryos were consistent with the allometry of juveniles and adults. Possible interpretations of this apparently anomalous scaling of embryonic metabolic rates are discussed. Mass-specific rates of oxygen consumption by ovigerous females (including the eggs) of both species were higher than for non-ovigerous crabs, in water and in air, and increased greatly during the development of the eggs. This difference was attributable mainly to the increasing metabolic rates of the attached embryos, but early ovigerous crabs (blastula stage) of both species also demonstrated a small elevation in metabolic rate by the crab itself, i.e. a metabolic cost of egg-bearing. In contrast, the elevation of the rate of oxygen consumption by late ovigerous females of C. lavauxi was less than predicted from the metabolic rate of eggs in a stirred respirometer. This suggests that, towards the end of development in C. lavauxi, the oxygen supply to the eggs in situ may be diffusion-limited by unstirred layers, an effect not observed for the larger eggs and more open egg clutch of H. rotundifrons. The cost of development, in terms of total oxygen consumption of single eggs, from extrusion to hatching, was 3.34 micromol O2 (approximately 1.5 J) for H. rotundifrons and 0.105 micromol O2 (approximately 0.05 J) for C. lavauxi. This 30-fold ratio approximates the ratios of their initial masses and yolk contents but represents only approximately one-third of the initial energy contents of the eggs.

Stage selection and restricted oviposition period improves cryopreservation of dipteran embryos.

PubMed

Rajamohan, Arun; Rinehart, Joseph P; Leopold, Roger A

2015-04-01

Embryos of two dipteran species (Musca domestica and Lucilia sericata) were assessed for an effective sampling time that would result in the highest post-cryopreservation hatch rate, with a primary goal to define species-specific egg collection periods and the effects of manual stage selection on post cryopreservation yield. The effects of the time taken to collect eggs on, (a) the proportion of embryos reaching a specific developmental stage between 17 and 20 h of development, and (b) the post-cryopreservation hatch rate were assessed. Permeabilization treatment applied at any stage of embryonic development did not significantly reduce embryo viability. Eggs collected over longer durations significantly reduced the number of embryos available in a specific developmental stage amenable to cryopreservation. Hatch percentage after cryopreservation of the embryos of M. domestica collected over a 60 min period was 10.7 ± 8.7% compared to 31 ± 5% for the eggs collected for just 15 min. Similarly, percent hatch in L. sericata resulted in 17.0 ± 3.9 and <2% for 15 and 60 min samples, respectively. Significantly higher hatching rates were obtained for cryopreservation after manual selection of specific embryonic developmental stages from the dechorionated samples. Post-cryopreservation hatching rate for stage-selected M. domestica embryos was 86.5 ± 5.5% compared to 33.3 ± 4.5% for embryos staged only by an overall visual confirmation. In the case of L. sericata, the hatching percentage was 79.0 ± 11.1 for stage-selected embryos compared to 17.0 ± 3.9% without individual selection. Published by Elsevier Inc.

DNA methylation analysis of the gene CDKN2B in Gallus gallus (chicken).

PubMed

Gryzińska, Magdalena; Andraszek, Katarzyna; Jocek, Grzegorz

2013-01-01

Methylation is an epigenetic modification of DNA affecting gene expression without changing the structure of nucleotides. It plays a crucial role in the embryonic and post-embryonic development of living organisms. Methylation level is tissue and species-specific and changes with age. The study was aimed at identifying the methylation of the CDKN2B gene situated at locus bar in Polbar chickens on the 6th and 18th day of embryonic development using the MSP (methylation-specific PCR) method. Methylation was not detected in the promoter region of gene CDKN2B on the 6th and 18th day of embryonic development. As one of the five genes responsible for melanine activity in melanocytes and highly active, it can contribute to the production of this pigment. The present research broadens the current knowledge of the chicken epigenome and the mechanism of autosexing in birds.

Bovine non-competent oocytes (BCB-) negatively impact the capacity of competent (BCB+) oocytes to undergo in vitro maturation, fertilisation and embryonic development.

PubMed

Salviano, M B; Collares, F J F; Becker, B S; Rodrigues, B A; Rodrigues, J L

2016-04-01

Competent oocyte selection remains a bottleneck in the in vitro production (IVP) of mammalian embryos. Among the vital assays described for selecting competent oocytes for IVP, the brilliant cresyl blue (BCB) test has shown consistent results. The aim of the first experiment was to observe if oocytes directly submitted to IVM show similar cleavage and blastocyst rates as those obtained with oocytes maintained under the same in vitro conditions as the oocytes that undergo the BCB test. Bovine cumulus-oocyte complexes (COCs) were recovered from slaughterhouse-derived ovaries and, after morphological evaluation, were randomised grouped into three groups: (1) directly submitted to IVM; (2) oocytes submitted to the BCB test without the addition of BCB stain (BCB control group); and (3) submitted to the BCB test. The results showed that oocytes directly submitted to IVM reached similar cleavage (48/80 - 60%) and embryonic development rates to the blastocyst stage (10/48 - 21%) as the results obtained with the BCB control group oocytes (45/77 - 58% and 08/45 - 18%, respectively). The aim of the second experiment was to determine the cleavage and blastocyst rates obtained from BCB+ oocytes undergoing IVM in the presence of BCB- oocytes at a ratio of 10:1. COCs were recovered from slaughterhouse-derived ovaries and, after morphological evaluation, were randomised into two groups that were submitted to IVM either directly (1: control group) or submitted to the BCB test prior to IVM. After the BCB test, the COCs were classified as either BCB+ (blue cytoplasm) or BCB- (colourless cytoplasm) and then divided into four experimental groups: (2) BCB+; (3) BCB-; and (4) BCB+ matured in same IVM medium drop as (5) BCB- at a ratio of 10:1. After IVM (24 h), oocytes from the different experimental groups were submitted to in vitro fertilisation (IVF) and in vitro culture (IVC) under the same culture conditions until they reached the blastocyst stage (D7). With regards to the cleavage rate (48 h after IVF), only group 3 (102/229 - 44%) differed (P < 0.05) from the other groups [1 (145/241 - 60%); 2 (150/225 - 67%); 4 (201/318 - 63%) and 5 (21/33 - 63%)]. On day 7, the embryos from group 2 (BCB+) achieved the highest blastocyst rate (46/150 - 31%) (P < 0.05) when compared with the embryo development capacity of the other experimental groups (1: 31/145 - 21%; group 3: 17/102 - 17%; group 4: 46/201 - 23%; and group 5: 2/21 - 10%). In conclusion, submitting BCB+ oocytes that were separated from BCB- oocytes to IVM increases the rate of embryonic development to the blastocyst stage when compared to the control group, BCB- oocyte group, BCB+ paracrine group and BCB- paracrine group. The presence of non-competent oocytes during IVM, even in low proportion (1:10), reduces the capacity of competent oocytes to undergo embryo development and achieve blastocyst stage during IVC.

Alterations to embryonic serotonin change aggression and fearfulness

USDA-ARS?s Scientific Manuscript database

Prenatal environment, including maternal hormones, affects the development of the serotonin (5-HT) system, with long-lasting effects on mood and behavioral exhibition in children and adults. The chicken provides a unique animal model to study the effects of embryonic development on childhood and ado...

In silico Testing of Environmental Impact on Embryonic Vascular Development

EPA Science Inventory

Understanding risks to embryonic development from exposure to environmental chemicals is a significant challenge given the diverse chemical landscape and paucity of data for most of these compounds. EPA’s Virtual Embryo project is building in silico models of morphogenesis to tes...

Developing an Experimental Model of Vascular Toxicity in Embryonic Zebrafish

EPA Science Inventory

Developing an Experimental Model of Vascular Toxicity in Embryonic Zebrafish Tamara Tal, Integrated Systems Toxicology Division, U.S. EPA Background: There are tens of thousands of chemicals that have yet to be fully evaluated for their toxicity by validated in vivo testing ...

Lipid content and fatty acid profile during lake whitefish embryonic development at different incubation temperatures.

PubMed

Mueller, Casey A; Doyle, Liam; Eme, John; Manzon, Richard G; Somers, Christopher M; Boreham, Douglas R; Wilson, Joanna Y

2017-01-01

Lipids serve as energy sources, structural components, and signaling molecules during fish embryonic development, and utilization of lipids may vary with temperature. Embryonic energy utilization under different temperatures is an important area of research in light of the changing global climate. Therefore, we examined percent lipid content and fatty acid profiles of lake whitefish (Coregonus clupeaformis) throughout embryonic development at three incubation temperatures. We sampled fertilized eggs and embryos at gastrulation, eyed and fin flutter stages following chronic incubation at temperatures of 1.8, 4.9 and 8.0°C. Hatchlings were also sampled following incubation at temperatures of 3.3, 4.9 and 8.0°C. Fertilized eggs had an initial high percentage of dry mass composed of lipid (percent lipid content; ~29%) consisting of ~20% saturated fatty acids (SFA), ~32% monounsaturated fatty acids (MUFA), ~44% polyunsaturated fatty acids (PUFA), and 4% unidentified. The most abundant fatty acids were 16:0, 16:1, 18:1(n-9c), 20:4(n-6), 20:5(n-3) and 22:6(n-3). This lipid profile matches that of other cold-water fish species. Percent lipid content increased during embryonic development, suggesting protein or other yolk components were preferentially used for energy. Total percentage of MUFA decreased during development, which indicated MUFA were the primary lipid catabolized for energy during embryonic development. Total percentage of PUFA increased during development, driven largely by an increase in 22:6(n-3). Temperature did not influence percent lipid content or percent MUFA at any development stage, and had inconsistent effects on percent SFA and percent PUFA during development. Thus, lake whitefish embryos appear to be highly adapted to low temperatures, and do not alter lipids in response to temperature within their natural incubation conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Impacts of maternal dietary protein intake on fetal survival, growth, and development.

PubMed

Herring, Cassandra M; Bazer, Fuller W; Johnson, Gregory A; Wu, Guoyao

2018-03-01

Maternal nutrition during gestation, especially dietary protein intake, is a key determinant in embryonic survival, growth, and development. Low maternal dietary protein intake can cause embryonic losses, intra-uterine growth restriction, and reduced postnatal growth due to a deficiency in specific amino acids that are important for cell metabolism and function. Of note, high maternal dietary protein intake can also result in intra-uterine growth restriction and embryonic death, due to amino acid excesses, as well as the toxicity of ammonia, homocysteine, and H 2 S that are generated from amino acid catabolism. Maternal protein nutrition has a pronounced impact on fetal programming and alters the expression of genes in the fetal genome. As a precursor to the synthesis of molecules (e.g. nitric oxide, polyamines, and creatine) with cell signaling and metabolic functions, L-arginine (Arg) is essential during pregnancy for growth and development of the conceptus. With inadequate maternal dietary protein intake, Arg and other important amino acids are deficient in mother and fetus. Dietary supplementation of Arg during gestation has been effective in improving embryonic survival and development of the conceptus in many species, including humans, pigs, sheep, mice, and rats. Both the balance among amino acids and their quantity are critical for healthy pregnancies and offspring. Impact statement This review aims at: highlighting adverse effects of elevated levels of ammonia in mother or fetus on embryonic/fetal survival, growth, and development; helping nutritionists and practitioners to understand the mechanisms whereby elevated levels of ammonia in mother or fetus results in embryonic/fetal death, growth restriction, and developmental abnormalities; and bringing, into the attention of nutritionists and practitioners, the problems of excess or inadequate dietary intake of protein or amino acids on pregnancy outcomes in animals and humans. The article provides new, effective means to improve embryonic/fetal survival and growth in mammals.

Effects of temperature on embryonic and early larval growth and development in the rough-skinned newt (Taricha granulosa).

PubMed

Smith, Geoffrey D; Hopkins, Gareth R; Mohammadi, Shabnam; M Skinner, Heather; Hansen, Tyler; Brodie, Edmund D; French, Susannah S

2015-07-01

We investigated the effects of temperature on the growth and development of embryonic and early larval stages of a western North American amphibian, the rough-skinned newt (Taricha granulosa). We assigned newt eggs to different temperatures (7, 14, or 21°C); after hatching, we re-assigned the newt larvae into the three different temperatures. Over the course of three to four weeks, we measured total length and developmental stage of the larvae. Our results indicated a strong positive relationship over time between temperature and both length and developmental stage. Importantly, individuals assigned to cooler embryonic temperatures did not achieve the larval sizes of individuals from the warmer embryonic treatments, regardless of larval temperature. Our investigation of growth and development at different temperatures demonstrates carry-over effects and provides a more comprehensive understanding of how organisms respond to temperature changes during early development. Copyright © 2015 Elsevier Ltd. All rights reserved.

De novo formation of nucleoli in developing mouse embryos originating from enucleolated zygotes.

PubMed

Kyogoku, Hirohisa; Fulka, Josef; Wakayama, Teruhiko; Miyano, Takashi

2014-06-01

The large, compact oocyte nucleoli, sometimes referred to as nucleolus precursor bodies (NPBs), are essential for embryonic development in mammals; in their absence, the oocytes complete maturation and can be fertilized, but no nucleoli are formed in the zygote or embryo, leading to developmental failure. It has been convincingly documented that zygotes inherit the oocyte nucleolar material and form NPBs again in pronuclei. It is commonly accepted that during early embryonic development, the original compact zygote NPBs gradually transform into reticulated nucleoli of somatic cells. Here, we show that zygote NPBs are not required for embryonic and full-term development in the mouse. When NPBs were removed from late-stage zygotes by micromanipulation, the enucleolated zygotes developed to the blastocyst stage and, after transfer to recipients, live pups were obtained. We also describe de novo formation of nucleoli in developing embryos. After removal of NPBs from zygotes, they formed new nucleoli after several divisions. These results indicate that the zygote NPBs are not used in embryonic development and that the nucleoli in developing embryos originate from de novo synthesized materials. © 2014. Published by The Company of Biologists Ltd.

Differentiation and Transplantation of Human Embryonic Stem Cell-Derived Hepatocytes

PubMed Central

Basma, Hesham; Soto-Gutiérrez, Alejandro; Yannam, Govardhana Rao; Liu, Liping; Ito, Ryotaro; Yamamoto, Toshiyuki; Ellis, Ewa; Carson, Steven D.; Sato, Shintaro; Chen, Yong; Muirhead, David; Navarro-Álvarez, Nalu; Wong, Ron; Roy-Chowdhury, Jayanta; Platt, Jeffrey L.; Mercer, David F.; Miller, John D.; Strom, Stephen C.; Kobayashi, Noaya; Fox, Ira J.

2009-01-01

Background & Aims The ability to obtain unlimited numbers of human hepatocytes would improve development of cell-based therapies for liver diseases, facilitate the study of liver biology and improve the early stages of drug discovery. Embryonic stem cells are pluripotent, can potentially differentiate into any cell type and could therefore be developed as a source of human hepatocytes. Methods To generate human hepatocytes, human embryonic stem cells were differentiated by sequential culture in fibroblast growth factor 2 and human Activin-A, hepatocyte growth factor, and dexamethasone. Functional hepatocytes were isolated by sorting for surface asialoglycoprotein receptor expression. Characterization was performed by real-time PCR, imunohistochemistry, immunoblot, functional assays and transplantation. Results Embryonic stem cell-derived hepatocytes expressed liver-specific genes but not genes representing other lineages, secreted functional human liver-specific proteins similar to those of primary human hepatocytes and demonstrated human hepatocyte cytochrome P450 metabolic activity. Serum from rodents given injections of embryonic stem cell-derived hepatocytes contained significant amounts of human albumin and alpha-1-antitrypsin. Colonies of cytokeratin-18 and human albumin-expressing cells were present in the livers of recipient animals. Conclusion Human embryonic stem cells can be differentiated into cells with many characteristics of primary human hepatocytes. Hepatocyte-like cells can be enriched and recovered based on asialoglycoprotein receptor expression and could potentially be used in drug discovery research and developed as therapeutics. PMID:19026649

Clonal analysis of Notch1-expressing cells reveals the existence of unipotent stem cells that retain long-term plasticity in the embryonic mammary gland.

PubMed

Lilja, Anna M; Rodilla, Veronica; Huyghe, Mathilde; Hannezo, Edouard; Landragin, Camille; Renaud, Olivier; Leroy, Olivier; Rulands, Steffen; Simons, Benjamin D; Fre, Silvia

2018-06-01

Recent lineage tracing studies have revealed that mammary gland homeostasis relies on unipotent stem cells. However, whether and when lineage restriction occurs during embryonic mammary development, and which signals orchestrate cell fate specification, remain unknown. Using a combination of in vivo clonal analysis with whole mount immunofluorescence and mathematical modelling of clonal dynamics, we found that embryonic multipotent mammary cells become lineage-restricted surprisingly early in development, with evidence for unipotency as early as E12.5 and no statistically discernable bipotency after E15.5. To gain insights into the mechanisms governing the switch from multipotency to unipotency, we used gain-of-function Notch1 mice and demonstrated that Notch activation cell autonomously dictates luminal cell fate specification to both embryonic and basally committed mammary cells. These functional studies have important implications for understanding the signals underlying cell plasticity and serve to clarify how reactivation of embryonic programs in adult cells can lead to cancer.

Transcriptional Profiling of Ectoderm Specification to Keratinocyte Fate in Human Embryonic Stem Cells

PubMed Central

Tadeu, Ana Mafalda Baptista; Lin, Samantha; Hou, Lin; Chung, Lisa; Zhong, Mei; Zhao, Hongyu; Horsley, Valerie

2015-01-01

In recent years, several studies have shed light into the processes that regulate epidermal specification and homeostasis. We previously showed that a broad-spectrum γ–secretase inhibitor DAPT promoted early keratinocyte specification in human embryonic stem cells triggered to undergo ectoderm specification. Here, we show that DAPT accelerates human embryonic stem cell differentiation and induces expression of the ectoderm protein AP2. Furthermore, we utilize RNA sequencing to identify several candidate regulators of ectoderm specification including those involved in epithelial and epidermal development in human embryonic stem cells. Genes associated with transcriptional regulation and growth factor activity are significantly enriched upon DAPT treatment during specification of human embryonic stem cells to the ectoderm lineage. The human ectoderm cell signature identified in this study contains several genes expressed in ectodermal and epithelial tissues. Importantly, these genes are also associated with skin disorders and ectodermal defects, providing a platform for understanding the biology of human epidermal keratinocyte development under diseased and homeostatic conditions. PMID:25849374

[Acceleration of Embryonic Development of Pinus sibirica Trees with a One-Year Reproductive Cycle].

PubMed

Tret'yakova, I N; Lukina, N V

2016-01-01

The study of the formation of embryonic structures in Pinus sibirica forms with a one-year reproductive cycle showed that the acceleration of the embryonic process manifested itself as a reduction of the coenocytic stage of the female gametophyte development (1.5 months instead of 1 year). The egg was not fertilized because of the asynchronous maturation of male and female gametophytes. Seeds without embryos were formed. We assumed that the acceleration of the reproductive process in Pinus sibirica was caused by a mutation in the female generative organs.

Effects of exposure to four endocrine disrupting-chemicals on fertilization and embryonic development of Barbel chub ( Squaliobarbus curriculus)

NASA Astrophysics Data System (ADS)

Niu, Cuijuan; Wang, Wei; Gao, Ying; Li, Li

2013-09-01

The toxicities of 4 common endocrine-disrupting chemicals (EDCs), 17β-estradiol (E2), p,p'-dichlorodiphenyldichloro-ethylene (DDE), 4-nonylphenol (NP) and tributyltin (TBT), to sperm motility, fertilization rate, hatching rate and embryonic development of Barbel chub ( Squaliobarbus curriculus) were investigated in this study. The duration of sperm motility was significantly shortened by exposure to the EDCs at the threshold concentrations of 10 ng L-1 for E2 and TBT, 1 μg L-1 for NP and 100 μg L-1 for DDE, respectively. The fertilization rate was substantially reduced by the EDCs at the lowest observable effect concentrations (LOECs) of 10 ng L-1 for E2 and TBT and 10 μg L-1 for DDE and NP, respectively. Of the tested properties of S. curriculus, larval deformity rate was most sensitive to EDC exposure and was significantly increased by DDE at the lowest experimental level of 0.1 μg L-1. Other EDCs increased the larval deformity rate at the LOECs of 1 ng L-1 for E2, 10 ng L-1 for TBT and 1 μg L-1 for NP, respectively. Despite their decreases with the increasing EDC concentrations, the hatching rate and larval survival rate of S. curriculus were not significantly affected by the exposure to EDCs. The results indicated that all the 4 EDCs affected significantly and negatively the early life stages of the freshwater fish S. curriculus. Overall, E2 and TBT were more toxic than NP and DDE, while DDE might be more toxic to larval deformity rate than to other measured parameters. Thus, the 4 EDCs showed potential negative influences on natural population dynamics of S. curriculus. Our findings provided valuable basic data for the ecological risk assessment of E2, DDE, NP and TBT.

Comparative ovicidal activity of Moringa oleifera leaf extracts on Fasciola gigantica eggs

PubMed Central

Hegazi, Ahmed G.; Megeed, Kadria N. Abdel; Hassan, Soad E.; Abdelaziz, M. M.; Toaleb, Nagwa I.; Shanawany, Eman E. El; Aboelsoued, Dina

2018-01-01

Background: Fasciolosis is an important zoonotic disease affecting the productive performance of farm animals in Egypt. Aim: The aim of the present study was comparing the ovicidal effect of different extracts as an alcoholic (Methanolic and Ethanolic) and aqueous Moringa oleifera leaf extracts on Fasciola gigantica non-embryonated and developed eggs. Materials and Methods: Tested concentrations of extracts ranged from 12.5 to 800 mg/ml. Nitroxynil was used as reference drug with a dose of 100 mg/ml. Results: M. oleifera alcoholic and aqueous extracts showed a concentration-dependent ovicidal effect on F. gigantica non-embryonated and developed eggs. Based on LC50 values, water extract showed the highest ovicidal activity since it registered the lowest values of 2.6 mg/ml on non-embryonated eggs. Non-embryonated eggs were more susceptible to aqueous extract than developed eggs. On the other hand, the developed eggs were more susceptible to ethanolic extract than non-embryonated eggs even the lowest LC50 (12.38 mg/ml). Conclusion: M. oleifera leaf extracts especially aqueous extract could be a promising step in the field of controlling fascioliasis. Further, in vivo studies are needed to enlighten the therapeutic potential of M. oleifera extracts in treating F. gigantica infection. PMID:29657406

The laboratory curse: variation in temperature stimulates embryonic development and shortens diapause

USDA-ARS?s Scientific Manuscript database

An ongoing biological debate is the difference in trait expression in continuous versus cycling temperature regimes, but are even daily cycling temperatures sufficient to generate natural expression of traits? We compared embryonic development and the duration of diapause for Mormon cricket eggs in...

Influence of ambient ultraviolet radiation on Bufo calamita egg development in a semiarid zone (Catalonia, Spain).

PubMed

Oromi, Neus; Marquis, Olivier; Miaud, Claude; Sanuy, Delfi

2008-01-01

Several experiments have shown that ambient ultraviolet-B radiation (UV-B) has negative effects on the development of amphibians' embryos. We studied the effects of UV-B radiation on development, survival and frequency of deformity during egg development in the Natterjack toad (Bufo calamita) from a semiarid region of Lleida (Catalonia, Spain). Eggs exposed to ambient levels of UV-B and those protected from UV-B with a filter exhibited similar developmental rate, mortality rate and frequency of developmental anomalies. These experiments show that eggs of Bufo calamita of the studied population are able to develop normally during embryonic period when exposed to current high levels of UV-B observed in Catalonia. These results will be used as reference for future studies on geographic variation in UV-B tolerance in this species.

[Embryonic stem cells and therapeutic cloning].

PubMed

Sunde, A; Eftedal, I

2001-08-30

Increased interest in the therapeutic use of human stem cells has emerged following significant progress in ongoing research. The cloning of a sheep, the isolation of human embryonic stem cells, and the discovery that adult stem cells may be reprogrammed taken together give substance to hopes that novel principles of treatment may be developed for a variety of serious conditions. Embryonic stem cells are derived from pre-embryos at the blastocyst stage and may give rise to all bodily tissues and cells. Animal models have demonstrated that embryonic stem cells when transplanted into adult hosts may differentiate and develop into cells and tissues applicable for treatment of a variety of conditions, including Parkinson's disease, multiple sclerosis, spinal injuries, cardiac stroke and cancer. Transplanted embryonic stem cells are exposed to immune reactions similar to those acting on organ transplants, hence immunosuppression of the recipient is generally required. It is, however, possible to obtain embryonic stem cells that are genetically identical to the patient's own cells by means of therapeutic cloning techniques. The nucleus from a somatic cell is transferred into an egg after removal of the egg's own genetic material. Under specific condition the egg will use genetic information from the somatic cell in organising the formation of a blastocyst which in turn generates embryonic stem cells. These cells have a genetic composition identical to that of the patient and are suitable for stem cell therapy.

Importance of the pluripotency factor LIN28 in the mammalian nucleolus during early embryonic development.

PubMed

Vogt, Edgar J; Meglicki, Maciej; Hartung, Kristina Ilka; Borsuk, Ewa; Behr, Rüdiger

2012-12-01

The maternal nucleolus is required for proper activation of the embryonic genome (EGA) and early embryonic development. Nucleologenesis is characterized by the transformation of a nucleolar precursor body (NPB) to a mature nucleolus during preimplantation development. However, the function of NPBs and the involved molecular factors are unknown. We uncover a novel role for the pluripotency factor LIN28, the biological significance of which was previously demonstrated in the reprogramming of human somatic cells to induced pluripotent stem (iPS) cells. Here, we show that LIN28 accumulates at the NPB and the mature nucleolus in mouse preimplantation embryos and embryonic stem cells (ESCs), where it colocalizes with the nucleolar marker B23 (nucleophosmin 1). LIN28 has nucleolar localization in non-human primate (NHP) preimplantation embryos, but is cytoplasmic in NHP ESCs. Lin28 transcripts show a striking decline before mouse EGA, whereas LIN28 protein localizes to NPBs at the time of EGA. Following knockdown with a Lin28 morpholino, the majority of embryos arrest between the 2- and 4-cell stages and never develop to morula or blastocyst. Lin28 morpholino-injected embryos arrested at the 2-cell stage were not enriched with nucleophosmin at presumptive NPB sites, indicating that functional NPBs were not assembled. Based on these results, we propose that LIN28 is an essential factor of nucleologenesis during early embryonic development.

Redundant functions of I-BAR family members, IRSp53 and IRTKS, are essential for embryonic development

PubMed Central

Chou, Ai Mei; Sem, Kai Ping; Lam, Wei Jun; Ahmed, Sohail; Lim, Chin Yan

2017-01-01

The insulin receptor substrate of 53 kDa, IRSp53, is an adaptor protein that works with activated GTPases, Cdc42 and Rac, to modulate actin dynamics and generate membrane protrusions in response to cell signaling. Adult mice that lack IRSp53 fail to regulate synaptic plasticity and exhibit hippocampus-associated learning deficiencies. Here, we show that 60% of IRSp53 null embryos die at mid to late gestation, indicating a vital IRSp53 function in embryonic development. We find that IRSp53 KO embryos displayed pleiotropic phenotypes such as developmental delay, oligodactyly and subcutaneous edema, and died of severely impaired cardiac and placental development. We further show that double knockout of IRSp53 and its closest family member, IRTKS, resulted in exacerbated placental abnormalities, particularly in spongiotrophoblast differentiation and development, giving rise to complete embryonic lethality. Hence, our findings demonstrate a hitherto under-appreciated IRSp53 function in embryonic development, and further establish an essential genetic interaction between IRSp53 and IRTKS in placental formation. PMID:28067313

Maternal thyroid hormones are essential for neural development in zebrafish.

PubMed

Campinho, Marco A; Saraiva, João; Florindo, Claudia; Power, Deborah M

2014-07-01

Teleost eggs contain an abundant store of maternal thyroid hormones (THs), and early in zebrafish embryonic development, all the genes necessary for TH signaling are expressed. Nonetheless the function of THs in embryonic development remains elusive. To test the hypothesis that THs are fundamental for zebrafish embryonic development, an monocarboxilic transporter 8 (Mct8) knockdown strategy was deployed to prevent maternal TH uptake. Absence of maternal THs did not affect early specification of the neural epithelia but profoundly modified later dorsal specification of the brain and spinal cord as well as specific neuron differentiation. Maternal THs acted upstream of pax2a, pax7, and pax8 genes but downstream of shha and fgf8a signaling. The lack of inhibitory spinal cord interneurons and increased motoneurons in the mct8 morphants is consistent with their stiff axial body and impaired mobility. The mct8 mutations are associated with X-linked mental retardation in humans, and the cellular and molecular consequences of MCT8 knockdown during embryonic development in zebrafish provides new insight into the potential role of THs in this condition.

Maternal Thyroid Hormones Are Essential for Neural Development in Zebrafish

PubMed Central

Saraiva, João; Florindo, Claudia; Power, Deborah M.

2014-01-01

Teleost eggs contain an abundant store of maternal thyroid hormones (THs), and early in zebrafish embryonic development, all the genes necessary for TH signaling are expressed. Nonetheless the function of THs in embryonic development remains elusive. To test the hypothesis that THs are fundamental for zebrafish embryonic development, an monocarboxilic transporter 8 (Mct8) knockdown strategy was deployed to prevent maternal TH uptake. Absence of maternal THs did not affect early specification of the neural epithelia but profoundly modified later dorsal specification of the brain and spinal cord as well as specific neuron differentiation. Maternal THs acted upstream of pax2a, pax7, and pax8 genes but downstream of shha and fgf8a signaling. The lack of inhibitory spinal cord interneurons and increased motoneurons in the mct8 morphants is consistent with their stiff axial body and impaired mobility. The mct8 mutations are associated with X-linked mental retardation in humans, and the cellular and molecular consequences of MCT8 knockdown during embryonic development in zebrafish provides new insight into the potential role of THs in this condition. PMID:24877564

The role of platelets during reproduction.

PubMed

Isermann, Berend; Nawroth, Peter P

2006-01-01

The availability of mice with defined defects within the hemostatic system enabled researchers to identify a role the coagulation system for embryonic and placental development. However, the role of platelets during development has only recently been experimentally addressed, giving some insight into potential functions of platelets during development. Thus, a quantitative embryonic platelet defect (severe thrombopenia secondary to NF-E2 deficiency) is associated with an embryonic growth retardation and reduced vascularisation of the placenta. Maternal platelet deficiency is associated with placental hemorrhage, which, however, does not impair embryonic or maternal survival. In vitro studies established that platelets or platelet conditioned medium regulate the invasive properties of human extravillous trophoblast cells and induce a phenotypical switch of trophoblast cells. These data imply that platelets are of relevance during placentation. Conversely, platelets and the formation of platelet-fibrin aggregates are dispensable for the development of the embryo proper, establishing that the lethal phenotypes observed in some embryo slacking coagulation regulators does not result from an inability to form platelet-fibrin aggregates, but likely reflects altered protease dependent signaling during vascular development.

4D display of the outflow track of embryonic-chick hearts (HH 14-19) using a high speed streak mode OCT

NASA Astrophysics Data System (ADS)

Ma, Siyu; Wang, Rui; Goodwin, Richard L.; Markwald, Roger R.; Borg, Thomas K.; Runyan, Raymond B.; Gao, Zhi

2013-02-01

Congenital Heart Disease (CHD) is the most common congenital malformation in newborns in the US. Although knowledge of CHD is limited, altered hemodynamic conditions are suspected as the factor that stimulates cardiovascular cell response, resulting in the heart morphology remodeling that ultimately causes CHDs. Therefore, one of recent efforts in CHD study is to develop high-speed imaging tools to correlate the rapidly changing hemodynamic condition and the morphological adaptations of an embryonic heart in vivo. We have developed a high-speed streak mode OCT that works at the center wavelength of 830 nm and is capable of providing images (292x220 μm2) of the outflow tract of an embryonic chick heart at the rate of 1000 Hz. The modality can provide a voxel resolution in the range of 10 μm3, and the spectral resolution allows a depth range of 1.63 mm. In the study reported here, each of the 4D images of an outflow tract was recorded for 2 seconds. The recording was conducted every 2 hours (HH17 to HH18), 3 hours (HH14 to HH17), and 4 hours (HH18 to HH19). Because of the fast scan speed, there is no need for postacquisition processing such as use of gating techniques to provide a fine 3D structure. In addition, more details of the outflow tract are preserved in the recorded images. The 4D images can be used in the future to determine the role of blood flow in CHD development.

Laying sequence interacts with incubation temperature to influence rate of embryonic development and hatching synchrony in a precocial bird.

PubMed

Hepp, Gary R; Kennamer, Robert A

2018-01-01

Incubation starts during egg laying for many bird species and causes developmental asynchrony within clutches. Faster development of late-laid eggs can help reduce developmental differences and synchronize hatching, which is important for precocial species whose young must leave the nest soon after hatching. In this study, we examined the effect of egg laying sequence on length of the incubation period in Wood Ducks (Aix sponsa). Because incubation temperature strongly influences embryonic development rates, we tested the interactive effects of laying sequence and incubation temperature on the ability of late-laid eggs to accelerate development and synchronize hatching. We also examined the potential cost of faster development on duckling body condition. Fresh eggs were collected and incubated at three biologically relevant temperatures (Low: 34.9°C, Medium: 35.8°C, and High: 37.6°C), and egg laying sequences from 1 to 12 were used. Length of the incubation period declined linearly as laying sequence advanced, but the relationship was strongest at medium temperatures followed by low temperatures and high temperatures. There was little support for including fresh egg mass in models of incubation period. Estimated differences in length of the incubation period between eggs 1 and 12 were 2.7 d, 1.2 d, and 0.7 d at medium, low and high temperatures, respectively. Only at intermediate incubation temperatures did development rates of late-laid eggs increase sufficiently to completely compensate for natural levels of developmental asynchrony that have been reported in Wood Duck clutches at the start of full incubation. Body condition of ducklings was strongly affected by fresh egg mass and incubation temperature but declined only slightly as laying sequence progressed. Our findings show that laying sequence and incubation temperature play important roles in helping to shape embryo development and hatching synchrony in a precocial bird.

Laying sequence interacts with incubation temperature to influence rate of embryonic development and hatching synchrony in a precocial bird

PubMed Central

Kennamer, Robert A.

2018-01-01

Incubation starts during egg laying for many bird species and causes developmental asynchrony within clutches. Faster development of late-laid eggs can help reduce developmental differences and synchronize hatching, which is important for precocial species whose young must leave the nest soon after hatching. In this study, we examined the effect of egg laying sequence on length of the incubation period in Wood Ducks (Aix sponsa). Because incubation temperature strongly influences embryonic development rates, we tested the interactive effects of laying sequence and incubation temperature on the ability of late-laid eggs to accelerate development and synchronize hatching. We also examined the potential cost of faster development on duckling body condition. Fresh eggs were collected and incubated at three biologically relevant temperatures (Low: 34.9°C, Medium: 35.8°C, and High: 37.6°C), and egg laying sequences from 1 to 12 were used. Length of the incubation period declined linearly as laying sequence advanced, but the relationship was strongest at medium temperatures followed by low temperatures and high temperatures. There was little support for including fresh egg mass in models of incubation period. Estimated differences in length of the incubation period between eggs 1 and 12 were 2.7 d, 1.2 d, and 0.7 d at medium, low and high temperatures, respectively. Only at intermediate incubation temperatures did development rates of late-laid eggs increase sufficiently to completely compensate for natural levels of developmental asynchrony that have been reported in Wood Duck clutches at the start of full incubation. Body condition of ducklings was strongly affected by fresh egg mass and incubation temperature but declined only slightly as laying sequence progressed. Our findings show that laying sequence and incubation temperature play important roles in helping to shape embryo development and hatching synchrony in a precocial bird. PMID:29373593

The essential role of endogenous ghrelin in growth hormone expression during zebrafish adenohypophysis development.

PubMed

Li, Xi; He, Jiangyan; Hu, Wei; Yin, Zhan

2009-06-01

Ghrelin, a multifunctional hormone, including potent GH stimulation activity, has been suggested to be important during embryonic development. Expression of ghrelin has been confirmed in the zebrafish pancreas during embryonic stages. Interfering with ghrelin function using two specific antisense morpholino oligonucleotides causes defects during zebrafish embryonic development. In ghrelin morphants the expression of GH was abolished in zebrafish somatotropes, whereas the expression patterns of the other key molecules involved in hypothalamic-pituitary development and distinct pituitary hormones genes remain largely intact at the appropriate time during zebrafish adenohypophysis development. Effective rescue of the ghrelin morphants with exogenous ghrelin mRNA showed that the correct gene had been targeted. Moreover, by analyzing the efficiencies of the ghrelin morphants rescue experiments with various forms of exogenous mutant ghrelin mRNAs, we also demonstrated the essentiality of the form acyl-ghrelin on GH stimulation during zebrafish adenohypophysis development. Our in vivo experiments, for the first time, also provided evidence of the existence of functional obestatin in the C-terminal part of zebrafish proghrelin peptides. Our research here has demonstrated that zebrafish is a unique model for functional studies of endogenous ghrelin, especially during embryonic development.

Developmental competence of different quality bovine oocytes retrieved through ovum pick-up following in vitro maturation and fertilization.

PubMed

Saini, N; Singh, M K; Shah, S M; Singh, K P; Kaushik, R; Manik, R S; Singla, S K; Palta, P; Chauhan, M S

2015-12-01

In the present study, oocytes retrieved from cross bred Karan Fries cows by ovum pick-up technique were graded into Group 1 and Group 2, based on the morphological appearance of the individual cumulus-oocyte complexes (COCs). To analyze whether the developmental potential of the COCs bears a relation to morphological appearance, relative expression of a panel of genes associated with; (a) cumulus-oocyte interaction (Cx43, Cx37, GDF9 and BMP15), (b) fertilization (ZP2 and ZP3), (c) embryonic development (HSF1, ZAR1 and bFGF) and (d) apoptosis and survival (BAX, BID and BCL-XL, MCL-1, respectively) was studied at two stages: germinal vesicle (GV) stage and after in vitro maturation. The competence was further corroborated by evaluating the embryonic progression of the presumed zygotes obtained from fertilization of the graded COCs. The gene expression profile and development rate in pooled A and B grade (Group 1) COCs and pooled C and D grade (Group 2) COCs were determined and compared according to the original grades. The results of the study demonstrated that the morphologically characterized Group 2 COCs showed significantly (P<0.05) lower expression for most of the genes related to cumulus-oocyte interplay, fertilization and embryonic development, both at GV stage as well as after maturation. Group 1 COCs also showed greater expression of anti-apoptotic genes (BCL-XL and MCL1) both at GV stage and after maturation, while pro-apoptotic genes (BAX and BID) showed significantly (P<0.05) elevated expression in poor quality COCs at both the stages. The cleavage rate in Group 1 COCs was significantly higher than that of Group 2 (74.46±7.06 v. 31.57±5.32%). The development of the presumed zygotes in Group 2 oocytes proceeded up to 8- to 16-cell stages only, while in Group 1 it progressed up to morulae (35.38±7.11%) and blastocyst stages (9.70±3.15%), indicating their better developmental potential.

Imaging of murine embryonic cardiovascular development using optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Huang, Yongyang; Degenhardt, Karl R.; Astrof, Sophie; Zhou, Chao

2016-03-01

We have demonstrated the capability of spectral domain optical coherence tomography (SDOCT) system to image full development of mouse embryonic cardiovascular system. Monitoring morphological changes of mouse embryonic heart occurred in different embryonic stages helps identify structural or functional cardiac anomalies and understand how these anomalies lead to congenital heart diseases (CHD) present at birth. In this study, mouse embryo hearts ranging from E9.5 to E15.5 were prepared and imaged in vitro. A customized spectral domain OCT system was used for imaging, with a central wavelength of 1310nm, spectral bandwidth of ~100nm and imaging speed of 47kHz A-scans/s. Axial resolution of this system was 8.3µm in air, and transverse resolution was 6.2 µm with 5X objective. Key features of mouse embryonic cardiovascular development such as vasculature remodeling into circulatory system, separation of atria and ventricles and emergence of valves could be clearly seen in three-dimensional OCT images. Optical clearing was applied to overcome the penetration limit of OCT system. With high resolution, fast imaging speed, 3D imaging capability, OCT proves to be a promising biomedical imaging modality for developmental biology studies, rivaling histology and micro-CT.

Dihydroartemisinin promotes angiogenesis during the early embryonic development of zebrafish

PubMed Central

Ba, Qian; Duan, Juan; Tian, Jia-qiang; Wang, Zi-liang; Chen, Tao; Li, Xiao-guang; Chen, Pei-zhan; Wu, Song-jie; Xiang, Li; Li, Jing-quan; Chu, Rui-ai; Wang, Hui

2013-01-01

Aim: To investigate the embryotoxicity of dihydroartemisinin (DHA), the main active metabolite of artemisinin, in zebrafish, and explore the corresponding mechanisms. Methods: The embryos of wild type and TG (flk1:GFP) transgenic zebrafish were exposed to DHA. Developmental phenotypes of the embryos were observed. Development of blood vessels was directly observed in living embryos of TG (flk1:GFP) transgenic zebrafish under fluorescence microscope. The expression of angiogenesis marker genes vegfa, flk1, and flt1 in the embryos was detected using real-time PCR and RNA in situ hybridization assays. Results: Exposure to DHA (1–10 mg/L) dose-dependently caused abnormal zebrafish embryonic phenotypes in the early developmental stage. Furthermore, exposure to DHA (10 mg/L) resulted in more pronounced embryonic angiogenesis in TG (flk1:GFP) zebrafish line. Exposure to DHA (10 mg/L) significantly increased the mRNA expression of vegfa, flk1, and flt1 in the embryos. Knockdown of the flk1 protein partially blocked the effects of DHA on embryogenesis. Conclusion: DHA causes abnormal embryonic phenotypes and promotes angiogenesis in zebrafish early embryonic development, demonstrating the potential embryotoxicity of DHA. PMID:23708556

Toxic effects of indoxacarb enantiomers on the embryonic development and induction of apoptosis in zebrafish larvae (Danio rerio).

PubMed

Fan, Yongmei; Feng, Qing; Lai, Kehua; Huang, Weikang; Zhang, Chenghui; Li, Qing X

2017-01-01

Indoxacarb is a highly potent insecticide widely used to control Lepidoptera insects in vegetable, tea, cotton, and rice fields. It can run off into aquatic environments. It is consisted of two enantiomers. Environmental risks and aquatic toxicity of indoxacarb enantiomers have not been fully investigated. In this study, zebrafish (Danio rerio) embryos were exposed to varying concentrations of (-)-R-indoxacarb and (+)-S-indoxacarb until 96-h post-fertilization (hpf) to assess the embryonic toxicity. (-)-R-indoxacarb was 1.3-fold more toxic than (+)-S-isomer to zebrafish embryos at 96 hpf. (-)-R-indoxacarb exhibited reduction in body length and pericardial edema compared with (+)-S-indoxacarb. (-)-R-indoxacarb decreased the hatching rate sixfold greater than (+)-S-indoxacarb. The rate of pericardial edema induced by (-)-R-indoxacarb was 2.5 times greater than that by (+)-S-indoxacarb. The heart rate of the larvae exposed to (-)-R-indoxacarb was 30% lower than that to (+)-S-indoxacarb. In addition, exposure to the chiral isomers resulted in significant increases in apoptosis; interestingly (-)-R-indoxacarb induced apoptosis in the heart area, whereas (+)-S-indoxacarb induced apoptosis in the head area. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 7-16, 2017. © 2015 Wiley Periodicals, Inc.

Alterations in biosynthetic accumulation of collagen types I and III during growth and morphogenesis of embryonic mouse salivary glands

NASA Technical Reports Server (NTRS)

Hardman, P.; Spooner, B. S.

1992-01-01

We examined the biosynthetic patterns of interstitial collagens in mouse embryonic submandibular and sublingual glands cultured in vitro. Rudiments explanted on day 13 of gestation and cultured for 24, 48, and 72 h all synthesized collagen types I, III, and V. However, while the total incorporation of label into collagenous proteins did not change over the three-day culture period, the rate of accumulation of newly synthesized types I and III did change. At 24 h, the ratio of newly synthesized collagen types I:III was approximately 2, whereas at 72 h, the ratio was approximately 5. These data suggest that collagen types I and III may be important in initiation of branching in this organ, but that type I may become dominant in the later stages of development and in maintenance of the adult organ.

Human embryonic stem cell phosphoproteome revealed by electron transfer dissociation tandem mass spectrometry.

PubMed

Swaney, Danielle L; Wenger, Craig D; Thomson, James A; Coon, Joshua J

2009-01-27

Protein phosphorylation is central to the understanding of cellular signaling, and cellular signaling is suggested to play a major role in the regulation of human embryonic stem (ES) cell pluripotency. Here, we describe the use of conventional tandem mass spectrometry-based sequencing technology--collision-activated dissociation (CAD)--and the more recently developed method electron transfer dissociation (ETD) to characterize the human ES cell phosphoproteome. In total, these experiments resulted in the identification of 11,995 unique phosphopeptides, corresponding to 10,844 nonredundant phosphorylation sites, at a 1% false discovery rate (FDR). Among these phosphorylation sites are 5 localized to 2 pluripotency critical transcription factors--OCT4 and SOX2. From these experiments, we conclude that ETD identifies a larger number of unique phosphopeptides than CAD (8,087 to 3,868), more frequently localizes the phosphorylation site to a specific residue (49.8% compared with 29.6%), and sequences whole classes of phosphopeptides previously unobserved.

A Cbfa1-dependent genetic pathway controls bone formation beyond embryonic development

PubMed Central

Ducy, Patricia; Starbuck, Michael; Priemel, Matthias; Shen, Jianhe; Pinero, Gerald; Geoffroy, Valerie; Amling, Michael; Karsenty, Gerard

1999-01-01

The molecular mechanisms controlling bone extracellular matrix (ECM) deposition by differentiated osteoblasts in postnatal life, called hereafter bone formation, are unknown. This contrasts with the growing knowledge about the genetic control of osteoblast differentiation during embryonic development. Cbfa1, a transcriptional activator of osteoblast differentiation during embryonic development, is also expressed in differentiated osteoblasts postnatally. The perinatal lethality occurring in Cbfa1-deficient mice has prevented so far the study of its function after birth. To determine if Cbfa1 plays a role during bone formation we generated transgenic mice overexpressing Cbfa1 DNA-binding domain (ΔCbfa1) in differentiated osteoblasts only postnatally. ΔCbfa1 has a higher affinity for DNA than Cbfa1 itself, has no transcriptional activity on its own, and can act in a dominant-negative manner in DNA cotransfection assays. ΔCbfa1-expressing mice have a normal skeleton at birth but develop an osteopenic phenotype thereafter. Dynamic histomorphometric studies show that this phenotype is caused by a major decrease in the bone formation rate in the face of a normal number of osteoblasts thus indicating that once osteoblasts are differentiated Cbfa1 regulates their function. Molecular analyses reveal that the expression of the genes expressed in osteoblasts and encoding bone ECM proteins is nearly abolished in transgenic mice, and ex vivo assays demonstrated that ΔCbfa1-expressing osteoblasts were less active than wild-type osteoblasts. We also show that Cbfa1 regulates positively the activity of its own promoter, which has the highest affinity Cbfa1-binding sites characterized. This study demonstrates that beyond its differentiation function Cbfa1 is the first transcriptional activator of bone formation identified to date and illustrates that developmentally important genes control physiological processes postnatally. PMID:10215629

Discovery of a novel oocyte-specific Krüppel-associated box domain-containing zinc finger protein required for early embryogenesis in cattle.

PubMed

Hand, Jacqelyn M; Zhang, Kun; Wang, Lei; Koganti, Prasanthi P; Mastrantoni, Kristen; Rajput, Sandeep K; Ashry, Mohamed; Smith, George W; Yao, Jianbo

2017-04-01

Zinc finger (ZNF) transcription factors interact with DNA through zinc finger motifs and play important roles in a variety of cellular functions including cell growth, proliferation, development, apoptosis, and intracellular signal transduction. One-third of ZNF proteins in metazoans contain a highly conserved N-terminal motif known as the Krüppel-associated box (KRAB) domain, which acts as a potent, DNA-binding dependent transcriptional repression module. Analysis of RNA-Seq data generated from a bovine oocyte cDNA library identified a novel transcript, which encodes a KRAB-containing ZNF transcription factor (named ZNFO). Characterization of ZNFO mRNA expression revealed that it is exclusively expressed in bovine oocytes and early embryos. A GFP reporter assay demonstrated that ZNFO protein localizes specifically to the nucleus, supporting its role in transcriptional regulation. To test the role of ZNFO in early embryonic development, zygotes were generated by in vitro maturation and fertilization of oocytes, and injected with small interfering RNA (siRNA) designed to knockdown ZNFO. Cleavage rates were not affected by ZNFO siRNA injection. However, embryonic development to 8- to 16-cell stage and blastocyst stage was significantly reduced relative to the uninjected and negative control siRNA-injected embryos. Further, interaction of ZNFO with the highly conserved co-factor, KRAB-associated protein-1 (KAP1), was demonstrated, and evidence supporting transcriptional repression by ZNFO was demonstrated using a GAL4-luciferase reporter system. Results of described studies demonstrate that ZNFO is a maternally-derived oocyte-specific nuclear factor required for early embryonic development in cattle, presumably functioning by repressing transcription. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of a 3D co-culture model using human stem cells for studying embryonic palatal fusion.

EPA Science Inventory

Morphogenetic tissue fusion is a critical and complex event in embryonic development and failure of this event leads to birth defects, such as cleft palate. Palatal fusion requires adhesion and subsequent dissolution of the medial epithelial layer of the mesenchymal palatal shelv...

Developing predictions of in vivo developmental toxicity of ToxCast chemicals using mouse embryonic stem cells.

EPA Science Inventory

Developing predictions of in vivo developmental toxicity of ToxCast chemicals using mouse embryonic stem cells S. Hunter, M. Rosen, M. Hoopes, H. Nichols, S. Jeffay, K. Chandler1, Integrated Systems Toxicology Division, National Health and Environmental Effects Research Labor...

Viviparity in high-altitude Phrynocephalus lizards is adaptive because embryos cannot fully develop without maternal thermoregulation.

PubMed

Wang, Zheng; Lu, Hong-Liang; Ma, Li; Ji, Xiang

2014-03-01

Viviparous Phrynocephalus lizards (Agamidae) are mainly restricted to the Qinghai-Tibet Plateau of China. In this study, we used Phrynocephalus vlangalii females kept under seven thermal regimes for the whole gestation period to test the hypothesis that viviparity in high-altitude Phrynocephalus lizards is adaptive because embryos cannot fully develop without maternal thermoregulation. All females at 24 °C and 93% of the females at 28 °C failed to give birth or produced stillborns, and proportionally fewer females gave birth at 29 or 35 °C than at 32 °C. Though the daily temperatures encountered were unsuitable for embryonic development, 95% of the females in nature and 89% of the females thermoregulating in the laboratory gave birth. There was no shift in the thermal preferences of females when they were pregnant. Although thermal conditions inside natural burrows were unsuitable for embryonic development, mass and sprint speed were both greater in neonates produced in nature. Our data show that (1) long-term exposure of P. vlangalii embryos to temperatures outside the range of 29-35 °C may result in the failure of development, but daily or short-term exposure may not necessarily increase embryonic mortality; (2) low gestation temperatures slow but do not arrest embryonic development, and females produce high-quality offspring in the shortest possible time by maintaining gestation temperatures close to the upper thermal limit for embryonic development; and (3) viviparity is currently adaptive at high elevations because embryos in nature cannot fully develop without relying on maternal thermoregulation. Our data validate the hypothesis tested.

Diverging functions of Scr between embryonic and post-embryonic development in a hemimetabolous insect, Oncopeltus fasciatus.

PubMed

Chesebro, John; Hrycaj, Steven; Mahfooz, Najmus; Popadić, Aleksandar

2009-05-01

Hemimetabolous insects undergo an ancestral mode of development in which embryos hatch into first nymphs that resemble miniature adults. While recent studies have shown that homeotic (hox) genes establish segmental identity of first nymphs during embryogenesis, no information exists on the function of these genes during post-embryogenesis. To determine whether and to what degree hox genes influence the formation of adult morphologies, we performed a functional analysis of Sex combs reduced (Scr) during post-embryonic development in Oncopeltus fasciatus. The main effect was observed in prothorax of Scr-RNAi adults, and ranged from significant alterations in its size and shape to a near complete transformation of its posterior half toward a T2-like identity. Furthermore, while the consecutive application of Scr-RNAi at both of the final two post-embryonic stages (fourth and fifth) did result in formation of ectopic wings on T1, the individual applications at each of these stages did not. These experiments provide two new insights into evolution of wings. First, the role of Scr in wing repression appears to be conserved in both holo- and hemimetabolous insects. Second, the prolonged Scr-depletion (spanning at least two nymphal stages) is both necessary and sufficient to restart wing program. At the same time, other structures that were previously established during embryogenesis are either unaffected (T1 legs) or display only minor changes (labium) in adults. These observations reveal a temporal and spatial divergence of Scr roles during embryonic (main effect in labium) and post-embryonic (main effect in prothorax) development.

Stage specific requirement of platelet-derived growth factor receptor-α in embryonic development.

PubMed

Qian, Chen; Wong, Carol Wing Yan; Wu, Zhongluan; He, Qiuming; Xia, Huimin; Tam, Paul Kwong Hang; Wong, Kenneth Kak Yuen; Lui, Vincent Chi Hang

2017-01-01

Platelet-derived growth factor receptor alpha (PDGFRα) is a cell-surface receptor tyrosine kinase for platelet-derived growth factors. Correct timing and level of Pdgfra expression is crucial for embryo development, and deletion of Pdgfra caused developmental defects of multiple endoderm and mesoderm derived structures, resulting in a complex phenotypes including orofacial cleft, spina bifida, rib deformities, and omphalocele in mice. However, it is not clear if deletion of Pdgfra at different embryonic stages differentially affects these structures. To address the temporal requirement of Pdgfra in embryonic development. We have deleted the Pdgfra in Pdgfra-expressing tissues at different embryonic stages in mice, examined and quantified the developmental anomalies. Current study showed that (i) conditional deletion of Pdgfra at different embryonic days (between E7.5 and E10.5) resulted in orofacial cleft, spina bifida, rib cage deformities, and omphalocele, and (ii) the day of Pdgfra deletion influenced the combinations, incidence and severities of these anomalies. Deletion of Pdgfra caused apoptosis of Pdgfra-expressing tissues, and developmental defects of their derivatives. Orofacial cleft, spina bifida and omphalocele are among the commonest skeletal and abdominal wall defects of newborns, but their genetic etiologies are largely unknown. The remarkable resemblance of our conditional Pdgfra knockout embryos to theses human congenital anomalies, suggesting that dysregulated PDGFRA expression could cause these anomalies in human. Future work should aim at defining (a) the regulatory elements for the expression of the human PDGFRA during embryonic development, and (b) if mutations / sequence variations of these regulatory elements cause these anomalies.

Diverging functions of Scr between embryonic and post-embryonic development in a hemimetabolous insect, Oncopeltus fasciatus

PubMed Central

Chesebro, John; Hrycaj, Steven; Mahfooz, Najmus; Popadić, Aleksandar

2009-01-01

Hemimetabolous insects undergo an ancestral mode of development in which embryos hatch into first nymphs that resemble miniature adults. While recent studies have shown that homeotic (hox) genes establish segmental identity of first nymphs during embryogenesis, no information exists on the function of these genes during post-embryogenesis. To determine whether and to what degree hox genes influence the formation of adult morphologies, we performed a functional analysis of Sex combs reduced (Scr) during post-embryonic development in Oncopeltus fasciatus. The main effect was observed in prothorax of Scr-RNAi adults, and ranged from significant alterations in its size and shape to a near complete transformation of its posterior half toward a T2-like identity. Furthermore, while the consecutive application of Scr-RNAi at both of the final two post-embryonic stages (fourth and fifth) did result in formation of ectopic wings on T1, the individual applications at each of these stages did not. These experiments provide two new insights into evolution of wings. First, the role of Scr in wing repression appears to be conserved in both holo- and hemimetabolous insects. Second, the prolonged Scr-depletion (spanning at least two nymphal stages) is both necessary and sufficient to restart wing program. At the same time, other structures that were previously established during embryogenesis are either unaffected (T1 legs) or display only minor changes (labium) in adults. These observations reveal a temporal and spatial divergence of Scr roles during embryonic (main effect in labium) and post-embryonic (main effect in prothorax) development. PMID:19382295

The primary role of zebrafish nanog is in extra-embryonic tissue.

PubMed

Gagnon, James A; Obbad, Kamal; Schier, Alexander F

2018-01-09

The role of the zebrafish transcription factor Nanog has been controversial. It has been suggested that Nanog is primarily required for the proper formation of the extra-embryonic yolk syncytial layer (YSL) and only indirectly regulates gene expression in embryonic cells. In an alternative scenario, Nanog has been proposed to directly regulate transcription in embryonic cells during zygotic genome activation. To clarify the roles of Nanog, we performed a detailed analysis of zebrafish nanog mutants. Whereas zygotic nanog mutants survive to adulthood, maternal-zygotic (MZ nanog ) and maternal mutants exhibit developmental arrest at the blastula stage. In the absence of Nanog, YSL formation and epiboly are abnormal, embryonic tissue detaches from the yolk, and the expression of dozens of YSL and embryonic genes is reduced. Epiboly defects can be rescued by generating chimeric embryos of MZ nanog embryonic tissue with wild-type vegetal tissue that includes the YSL and yolk cell. Notably, cells lacking Nanog readily respond to Nodal signals and when transplanted into wild-type hosts proliferate and contribute to embryonic tissues and adult organs from all germ layers. These results indicate that zebrafish Nanog is necessary for proper YSL development but is not directly required for embryonic cell differentiation. © 2018. Published by The Company of Biologists Ltd.

Metabolic rate and life stage of the mites Tetranychus cinnabarinus boisd. (Prostigmata) and Phytoseiulus persimilis A-H. (Mesostigmata).

PubMed

Thurling, D J

1980-09-01

Respiration rates (oxygen uptake per individual) of the herbivorous mite Tetranychus cinnabarinus Boisd. and of the predatory mite Phytoseiulus persimilis A-H. were measured at 25°C for all life stages, including eggs, using a Cartesian Diver micro-respirometer.Metabolic rates (oxygen uptake per unit weight) ranged between 0.27 and 2.32 nl O 2 μg -1 live weight h -1 in T. cinnabarinus, and between 0.99 and 3.69 nl O 2 μg -1 live weight h -1 in P. persimilis. The difference in metabolic rate ranges is attributed to different modes of life. The metabolic rates of both species are higher than those of comparable mite species, which is attributed to their small size, rapid development and limited sclerotization.Respiration-body weight regression gave the single equation log 10 R=-0.091+1.213 log 10 W for all post-embryonic stages of T. cinnabarinus but two equations for P. persimilis of log 10 R=0.394+1.116 log 10 W for gravid females and log 10 R=0.880+0.348 log 10 W for all non-reproducing post-embryonic stages. The single respiration-body weight relationship for T. cinnabarinus reflects the continuous growth pattern of this species, and the two relationships for P. persimilis reflect the accelerated growth following fertilization. The significance of these results for invertebrate population metabolism studies is discussed.

Conserved developmental alternative splicing of muscleblind-like (MBNL) transcripts regulates MBNL localization and activity.

PubMed

Terenzi, Fulvia; Ladd, Andrea N

2010-01-01

Muscleblind-like (MBNL) proteins have been shown to regulate pre-mRNA alternative splicing, and MBNL1 has been implicated in regulating fetal-to-adult transitions in alternative splicing in the heart. MBNL1 is highly conserved, exhibiting more than 95% identity at the amino acid level between birds and mammals. To investigate MBNL1 expression during embryonic heart development, we examined MBNL1 transcript and protein expression in the embryonic chicken heart from the formation of the primitive heart tube through cardiac morphogenesis (embryonic days 1.5 through 8). MBNL1 transcript levels remained steady throughout these stages, whereas MBNL1 protein levels increased and exhibited a shift in isoforms. MBNL1 has several alternatively spliced exons. Using RT-PCR, we determined that the inclusion of one of these, exon 5, decreases dramatically during cardiac morphogenesis. This developmental transition is conserved in mice. Functional analyses of MBNL1 isoforms containing or lacking exon 5-encoded sequences revealed that exon 5 is important for the regulation of the subcellular localization, RNA binding affinity, and alternative splicing activity of MBNL1 proteins. A second MBNL protein, MBNL2, is also expressed in the embryonic heart. We found that MBNL2 exon 5, which is paralogous to MBNL1 exon 5, is similarly regulated during embryonic heart development. Analysis of MBNL1 and MBNL2 transcripts in several embryonic tissues in chicken and mouse indicate that exon 5 alternative splicing is highly conserved and tissue-specific. Thus, we propose that conserved developmental stage- and tissue-specific alternative splicing of MBNL transcripts is an important mechanism by which MBNL activity is regulated during embryonic development.

Impaired Embryonic Development in Mice Overexpressing the RNA-Binding Protein TIAR

PubMed Central

Kharraz, Yacine; Salmand, Pierre-Adrien; Camus, Anne; Auriol, Jacques; Gueydan, Cyril; Kruys, Véronique; Morello, Dominique

2010-01-01

Background TIA-1-related (TIAR) protein is a shuttling RNA-binding protein involved in several steps of RNA metabolism. While in the nucleus TIAR participates to alternative splicing events, in the cytoplasm TIAR acts as a translational repressor on specific transcripts such as those containing AU-Rich Elements (AREs). Due to its ability to assemble abortive pre-initiation complexes coalescing into cytoplasmic granules called stress granules, TIAR is also involved in the general translational arrest observed in cells exposed to environmental stress. However, the in vivo role of this protein has not been studied so far mainly due to severe embryonic lethality upon tiar invalidation. Methodology/Principal Findings To examine potential TIAR tissue-specificity in various cellular contexts, either embryonic or adult, we constructed a TIAR transgenic allele (loxPGFPloxPTIAR) allowing the conditional expression of TIAR protein upon Cre recombinase activity. Here, we report the role of TIAR during mouse embryogenesis. We observed that early TIAR overexpression led to low transgene transmission associated with embryonic lethality starting at early post-implantation stages. Interestingly, while pre-implantation steps evolved correctly in utero, in vitro cultured embryos were very sensitive to culture medium. Control and transgenic embryos developed equally well in the G2 medium, whereas culture in M16 medium led to the phosphorylation of eIF2α that accumulated in cytoplasmic granules precluding transgenic blastocyst hatching. Our results thus reveal a differential TIAR-mediated embryonic response following artificial or natural growth environment. Conclusions/Significance This study reports the importance of the tightly balanced expression of the RNA-binding protein TIAR for normal embryonic development, thereby emphasizing the role of post-transcriptional regulations in early embryonic programming. PMID:20596534

Medical Student Retention of Embryonic Development: Impact of the Dimensions Added by Multimedia Tutorials

ERIC Educational Resources Information Center

Marsh, Karen R.; Giffin, Bruce F.; Lowrie, Donald J., Jr.

2008-01-01

The purpose of this project was to develop Web-based learning modules that combine (1) animated 3D graphics; (2) 3D models that a student can manipulate independently; (3) passage of time in embryonic development; and (4) animated 2D graphics, including 2D cross-sections that represent different "slices" of the embryo, and animate in…

Does gravity influence the early stages of the development of the nervous system in an amphibian?

PubMed

Duprat, A M; Husson, D; Gualandris-Parisot, L

1998-11-01

As a result of previous studies using hypergravity (centrifuge) or virtual microgravity (clinostat), it was proposed that gravity was involved in embryonic development, i.e., in the establishment of the embryonic polarities and the body plan pattern which subsequently direct morphogenesis and organogenesis of the central nervous system and of sensory organs. Recent experiments were performed in space using sounding rockets and orbiting space-modules to ascertain whether gravity is indeed required for embryogenesis in Invertebrates and Vertebrates. Eggs fertilised in vivo or in vitro in microgravity showed some abnormalities during embryonic development but were able to regulate and produce nearly normal larvae. Copyright 1998 Elsevier Science B.V.

Kisspeptin regulates ovarian steroidogenesis during delayed embryonic development in the fruit bat, Cynopterus sphinx.

PubMed

Anuradha; Krishna, Amitabh

2017-11-01

Cynopterus sphinx, a fruit bat, undergoes delayed embryonic development during the winter months, a period that corresponds to low levels of progesterone and estradiol synthesis by the ovary. Kisspeptins (KPs) are a group of neuropeptide hormones that act via G-protein coupled receptor 54 (GPR54) to stimulate hypothalamic secretion of Gonadotropin-releasing hormone, thereby regulating ovarian steroidogenesis, folliculogenesis, and ovulation. GPR54 is also expressed in the ovary, suggesting a direct role for KPs in ovarian steroidogenesis. The aim of present study was to determine if a low serum level of KP is responsible for reduced progesterone and estradiol levels during the period of delayed embryonic development in C. sphinx. Indeed, low serum KP abundance corresponded to reduced expression of GPR54 in ovarian luteal cells during the period of delayed development compared to normal development. In vitro and in vivo treatment with KP increased GPR54 abundance, via Extracellular signal regulated kinase and its downstream mediators, leading to increased progesterone synthesis in the ovary during delayed embryonic development. KP treatment also increased cholesterol uptake and elevated expression of Luteinizing hormone receptor and Steroid acute regulatory protein in the ovary, suggesting that elevation in circulating KP during delayed embryonic development may reactivate luteal activity. KPs may also enhance cell survival (BCL-2, reduced Caspase 3 activity) and angiogenesis (Vascular endothelium growth factor) during this period. The findings of this study thus demonstrate a regulatory role for KPs in the maintenance of luteal steroidogenesis during pregnancy in C. sphinx. © 2017 Wiley Periodicals, Inc.

An integrated miRNA functional screening and target validation method for organ morphogenesis.

PubMed

Rebustini, Ivan T; Vlahos, Maryann; Packer, Trevor; Kukuruzinska, Maria A; Maas, Richard L

2016-03-16

The relative ease of identifying microRNAs and their increasing recognition as important regulators of organogenesis motivate the development of methods to efficiently assess microRNA function during organ morphogenesis. In this context, embryonic organ explants provide a reliable and reproducible system that recapitulates some of the important early morphogenetic processes during organ development. Here we present a method to target microRNA function in explanted mouse embryonic organs. Our method combines the use of peptide-based nanoparticles to transfect specific microRNA inhibitors or activators into embryonic organ explants, with a microRNA pulldown assay that allows direct identification of microRNA targets. This method provides effective assessment of microRNA function during organ morphogenesis, allows prioritization of multiple microRNAs in parallel for subsequent genetic approaches, and can be applied to a variety of embryonic organs.

Rotational imaging optical coherence tomography for full-body mouse embryonic imaging

PubMed Central

Wu, Chen; Sudheendran, Narendran; Singh, Manmohan; Larina, Irina V.; Dickinson, Mary E.; Larin, Kirill V.

2016-01-01

Abstract. Optical coherence tomography (OCT) has been widely used to study mammalian embryonic development with the advantages of high spatial and temporal resolutions and without the need for any contrast enhancement probes. However, the limited imaging depth of traditional OCT might prohibit visualization of the full embryonic body. To overcome this limitation, we have developed a new methodology to enhance the imaging range of OCT in embryonic day (E) 9.5 and 10.5 mouse embryos using rotational imaging. Rotational imaging OCT (RI-OCT) enables full-body imaging of mouse embryos by performing multiangle imaging. A series of postprocessing procedures was performed on each cross-section image, resulting in the final composited image. The results demonstrate that RI-OCT is able to improve the visualization of internal mouse embryo structures as compared to conventional OCT. PMID:26848543

UTX regulates mesoderm differentiation of embryonic stem cells independent of H3K27 demethylase activity.

PubMed

Wang, Chaochen; Lee, Ji-Eun; Cho, Young-Wook; Xiao, Ying; Jin, Qihuang; Liu, Chengyu; Ge, Kai

2012-09-18

To investigate the role of histone H3K27 demethylase UTX in embryonic stem (ES) cell differentiation, we have generated UTX knockout (KO) and enzyme-dead knock-in male ES cells. Deletion of the X-chromosome-encoded UTX gene in male ES cells markedly decreases expression of the paralogous UTY gene encoded by Y chromosome, but has no effect on global H3K27me3 level, Hox gene expression, or ES cell self-renewal. However, UTX KO cells show severe defects in mesoderm differentiation and induction of Brachyury, a transcription factor essential for mesoderm development. Surprisingly, UTX regulates mesoderm differentiation and Brachyury expression independent of its enzymatic activity. UTY, which lacks detectable demethylase activity, compensates for the loss of UTX in regulating Brachyury expression. UTX and UTY bind directly to Brachyury promoter and are required for Wnt/β-catenin signaling-induced Brachyury expression in ES cells. Interestingly, male UTX KO embryos express normal levels of UTY and survive until birth. In contrast, female UTX KO mice, which lack the UTY gene, show embryonic lethality before embryonic day 11.5. Female UTX KO embryos show severe defects in both Brachyury expression and embryonic development of mesoderm-derived posterior notochord, cardiac, and hematopoietic tissues. These results indicate that UTX controls mesoderm differentiation and Brachyury expression independent of H3K27 demethylase activity, and suggest that UTX and UTY are functionally redundant in ES cell differentiation and early embryonic development.

Evaluation of treatments with hCG and carprofen at embryo transfer in a demi-embryo and recipient virgin heifer model.

PubMed

Torres, A; Chagas E Silva, J; Diniz, P; Lopes-da-Costa, L

2013-08-01

An in vivo model, combining a low developmental competence embryo (demi-embryo) and a high-fertility recipient (virgin dairy heifer) was used to evaluate the effects of treatment with human chorionic gonadotropin (hCG) and carprofen at embryo transfer (ET) on plasma progesterone (P₄) concentrations of recipients and on embryonic growth and survival. Embryos were bisected and each demi-embryo was transferred to a recipient on Day 7 of the estrous cycle. At ET, heifers (n = 163) were randomly allocated to treatment with hCG (2500 IU im), carprofen (500 mg iv), hCG plus carprofen or to untreated controls. Plasma P₄ concentrations were measured on Days 0, 7, 14 and 21 of all recipients plus on Days 28, 42 and 63 of pregnant recipients. Pregnancy was presumed to be present in recipients with luteal plasma P4 concentrations until Day 21 and confirmed by using transrectal ultrasonography on Days 28, 42 and 63. Embryonic measurements (crown-rump length and width) were obtained on Day 42. Treatment with hCG induced formation of secondary corpora lutea (CL) in 97% of heifers and increased (P < 0.01) mean plasma P₄ concentrations of non-pregnant recipients on Day 14 and of pregnant heifers on Days 14 to 63. This was associated to a significant decrease in early embryonic mortality. In contrast, subsequent embryonic losses resulted in a non-significant numerical increase by 8% of pregnancies maintained to Day 63. Therefore, treatment with hCG significantly rescued embryos through the maternal recognition of pregnancy window but was not able to support development thereafter. Treatment with carprofen at ET had no significant effects on plasma P₄ concentrations and rate of embryo mortality. Treatment with hCG plus carprofen at ET induced formation of secondary CL in 90% of heifers but decreased the luteotrophic effect of hCG, resulting in no effect on embryo survival. Low developmental competence embryos showed an intrinsic deficiency in overcoming the maternal recognition of pregnancy challenge and in proceeding to further development until Day 28 of pregnancy, whereas mortality beyond this point was residual. Results on pregnancy rates should be confirmed in further experiments involving a larger sample size.

EMG1 is essential for mouse pre-implantation embryo development.

PubMed

Wu, Xiaoli; Sandhu, Sumit; Patel, Nehal; Triggs-Raine, Barbara; Ding, Hao

2010-09-21

Essential for mitotic growth 1 (EMG1) is a highly conserved nucleolar protein identified in yeast to have a critical function in ribosome biogenesis. A mutation in the human EMG1 homolog causes Bowen-Conradi syndrome (BCS), a developmental disorder characterized by severe growth failure and psychomotor retardation leading to death in early childhood. To begin to understand the role of EMG1 in mammalian development, and how its deficiency could lead to Bowen-Conradi syndrome, we have used mouse as a model. The expression of Emg1 during mouse development was examined and mice carrying a null mutation for Emg1 were generated and characterized. Our studies indicated that Emg1 is broadly expressed during early mouse embryonic development. However, in late embryonic stages and during postnatal development, Emg1 exhibited specific expression patterns. To assess a developmental role for EMG1 in vivo, we exploited a mouse gene-targeting approach. Loss of EMG1 function in mice arrested embryonic development prior to the blastocyst stage. The arrested Emg1-/- embryos exhibited defects in early cell lineage-specification as well as in nucleologenesis. Further, loss of p53, which has been shown to rescue some phenotypes resulting from defects in ribosome biogenesis, failed to rescue the Emg1-/- pre-implantation lethality. Our data demonstrate that Emg1 is highly expressed during mouse embryonic development, and essential for mouse pre-implantation development. The absolute requirement for EMG1 in early embryonic development is consistent with its essential role in yeast. Further, our findings also lend support to the previous study that showed Bowen-Conradi syndrome results from a partial EMG1 deficiency. A complete deficiency would not be expected to be compatible with a live birth.

ELF (Extremely Low Frequency) Communications System Ecological Monitoring Program: Summary of 1987 Progress

DTIC Science & Technology

1989-04-01

Development . Prenatal developmental stages are especially sensitive to environmental perturbations. At present, there is conflicting evidence of direct EM...effects on embryonic or fetal development . In addition, possible effects of the ELF system on parental behavior could also have an indirect effect on... development . The purpose of this element is to determine the incidence of abnormalities in embryonic development in tree swallows at treatment and control

Studying the Physiology of Tadpoles through their Naturally Transparent Abdomen Walls

NASA Astrophysics Data System (ADS)

Naitoh, T.; Yamashita, M.; Wassersug, R.

Because their development is external and they grow rapidly, anurans (frogs and toads) have been important model species in studies of how spaceflight affects vertebrate development. However the long term effects of spaceflight on post embryonic stages have barely been studied in these, or for that matter, any other vertebrate species. Tadpoles of certain species have naturally transparent skin covering a large portion of their ventral abdomen wall. Consequently viscera and visceral movements can be observed through this window without any invasive treatment to the animals. Respiration rate (as measured by buccal floor movements), heart rate, and gut motility are all indices of physiological state that can be observed in unconstrained larvae of these particular anuran species. We are using changes in these physiological variables to study the responses of tadpoles to changes in their external environment. Our study of the physiological responses of these tadpoles to microgravity has been selected as a candidate spaceflight experiment (to be housed in the Canadian Aquatic Research Facility). Ground-based studies with these same larvae are currently underway. Those experiments make use of stepwise changes in temperature as a stimulus to document the effect of temperature on intestinal motility in tadpoles. The scope of our studies on gravitational physiology and key issues in post- embryonic development of anurans are the focus of our presentation. This research is a prelude to raising a vertebrate through a complete life cycle in the space environment.

In vitro organogenesis of gut-like structures from mouse embryonic stem cells.

PubMed

Kuwahara, M; Ogaeri, T; Matsuura, R; Kogo, H; Fujimoto, T; Torihashi, S

2004-04-01

Embryonic stem (ES) cells have pluripotency and give rise to many cell types and tissues, including representatives of all three germ layers in the embryo. We have reported previously that mouse ES cells formed contracting gut-like organs from embryoid bodies (EBs). These gut-like structures contracted spontaneously, and had large lumens surrounded by three layers, i.e. epithelium, lamina propria and muscularis. Ganglia were scattered along the periphery, and interstitial cells of Cajal (ICC) were distributed among the smooth muscle cells. In the present study, to determine whether they can be a model of gut organogenesis, we investigated the formation process of the gut-like structures in comparison with embryonic gut development. As a result, we found that the fundamental process of formation in vitro was similar to embryonic gut development in vivo. The result indicates that the gut-like structure is a useful tool not only for developmental study to determine the factors that induce gut organogenesis, but also for studies of enteric neurone and ICC development.

Effects of catechins and low temperature on embryonic development and hatching in Heterodera glycines and Meloidogyne incognita

USDA-ARS?s Scientific Manuscript database

Mimics of two natural influences, a chemical similar to one present in cyst nematodes and low temperature exposure of nematode eggs, were evaluated for their effects on quantitative and qualitative features of embryonic development and hatching. The polyphenol epigallocatechin gallate (EGCG), an ana...

Part I. Embryonic surgery using femtosecond laser pulses for the delivery of exogenous materials and the analysis of gene expression

NASA Astrophysics Data System (ADS)

Kohli, V.; Elezzabi, A. Y.

2008-02-01

Herein, we demonstrate the application of high-intensity femtosecond (fs) laser pulses for performing laser surgery on the embryonic cells of developing zebrafish (Danio rerio). When fs laser pulses were focused onto individual blastomeres, transient pores were formed exposing the extracellular space to the intracellular environment. Utilizing the transient pores as a pathway for delivery of exogenous material, both chorionated and dechorionated zebrafish embryos were successfully loaded with a fluorescent reporter molecule (fluorescein isothiocyanate (FITC)). Streptavidin-conjugated quantum dots or plasmid DNA (Simian-CMV-EGFP). Both FITC and quantum dots were found to disperse throughout the blastomere cells as the embryo developed. Gene expression was seen in 24 hour post-fertilized embryos, with fluorescence observed in the notochord, floor plates, somites and tails of the larvae. We also determined the survivability of laser-manipulated embryos by rearing zebrafish from early to mid cleavage stage (2-cell to 8/16-cell) to pec-fin stage. Survival rates of 89 and 100 % were found for dechorionated and chorionated embryos, respectively.

Mouse mutants from chemically mutagenized embryonic stem cells

PubMed Central

Munroe, Robert J.; Bergstrom, Rebecca A.; Zheng, Qing Yin; Libby, Brian; Smith, Richard; John, Simon W.M.; Schimenti, Kerry J.; Browning, Victoria L.; Schimenti, John C.

2010-01-01

The drive to characterize functions of human genes on a global scale has stimulated interest in large-scale generation of mouse mutants. Conventional germ-cell mutagenesis with N-ethyl-N-nitrosourea (ENU) is compromised by an inability to monitor mutation efficiency, strain1 and interlocus2 variation in mutation induction, and extensive husbandry requirements. To overcome these obstacles and develop new methods for generating mouse mutants, we devised protocols to generate germline chi-maeric mice from embryonic stem (ES) cells heavily mutagenized with ethylmethanesulphonate (EMS). Germline chimaeras were derived from cultures that underwent a mutation rate of up to 1 in 1,200 at the Hprt locus (encoding hypoxanthine guanine phosphoribosyl transferase). The spectrum of mutations induced by EMS and the frameshift mutagen ICR191 was consistent with that observed in other mammalian cells. Chimaeras derived from ES cells treated with EMS transmitted mutations affecting several processes, including limb development, hair growth, hearing and gametogenesis. This technology affords several advantages over traditional mutagenesis, including the ability to conduct shortened breeding schemes and to screen for mutant phenotypes directly in ES cells or their differentiated derivatives. PMID:10700192

Physical-chemical mechanisms of pattern formation during gastrulation

NASA Astrophysics Data System (ADS)

Bozorgui, Behnaz; Kolomeisky, Anatoly B.; Teimouri, Hamid

2018-03-01

Gastrulation is a fundamental phase during the biological development of most animals when a single layer of identical embryo cells is transformed into a three-layer structure, from which the organs start to develop. Despite a remarkable progress in quantifying the gastrulation processes, molecular mechanisms of these processes remain not well understood. Here we theoretically investigate early spatial patterning in a geometrically confined colony of embryonic stem cells. Using a reaction-diffusion model, a role of Bone-Morphogenetic Protein 4 (BMP4) signaling pathway in gastrulation is specifically analyzed. Our results show that for slow diffusion rates of BMP4 molecules, a new length scale appears, which is independent of the size of the system. This length scale separates the central region of the colony with uniform low concentrations of BMP molecules from the region near the colony edge where the concentration of signaling molecules is elevated. The roles of different components of the signaling pathway are also explained. Theoretical results are consistent with recent in vitro experiments, providing microscopic explanations for some features of early embryonic spatial patterning. Physical-chemical mechanisms of these processes are discussed.

Tension (re)builds: Biophysical mechanisms of embryonic wound repair.

PubMed

Zulueta-Coarasa, Teresa; Fernandez-Gonzalez, Rodrigo

2017-04-01

Embryonic tissues display an outstanding ability to rapidly repair wounds. Epithelia, in particular, serve as protective layers that line internal organs and form the skin. Thus, maintenance of epithelial integrity is of utmost importance for animal survival, particularly at embryonic stages, when an immune system has not yet fully developed. Rapid embryonic repair of epithelial tissues is conserved across species, and involves the collective migration of the cells around the wound. The migratory cell behaviours associated with wound repair require the generation and transmission of mechanical forces, not only for the cells to move, but also to coordinate their movements. Here, we review the forces involved in embryonic wound repair. We discuss how different force-generating structures are assembled at the molecular level, and the mechanisms that maintain the balance between force-generating structures as wounds close. Finally, we describe the mechanisms that cells use to coordinate the generation of mechanical forces around the wound. Collective cell movements and their misregulation have been associated with defective tissue repair, developmental abnormalities and cancer metastasis. Thus, we propose that understanding the role of mechanical forces during embryonic wound closure will be crucial to develop therapeutic interventions that promote or prevent collective cell movements under pathological conditions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Maternal dietary zinc supplementation enhances the epigenetic-activated antioxidant ability of chick embryos from maternal normal and high temperatures.

PubMed

Zhu, Yongwen; Liao, Xiudong; Lu, Lin; Li, Wenxiang; Zhang, Liyang; Ji, Cheng; Lin, Xi; Liu, Hsiao-Ching; Odle, Jack; Luo, Xugang

2017-03-21

The role of maternal dietary zinc supplementation in protecting the embryos from maternal hyperthermia-induced negative effects via epigenetic mechanisms was examined using an avian model (Gallus gallus). Broiler breeder hens were exposed to two maternal temperatures (21°C and 32°C) × three maternal dietary zinc treatments (zinc-unsupplemented control diet, the control diet + 110 mg zinc/kg inorganic or organic zinc) for 8 weeks. Maternal hyperthermia increased the embryonic mortality and induced oxidative damage evidenced by the elevated mRNA expressions of heat shock protein genes. Maternal dietary zinc deficiency damaged the embryonic development associated with the global DNA hypomethylation and histone 3 lysine 9 hyperacetylation in the embryonic liver. Supplementation of zinc in maternal diets effectively eliminated the embryonic mortality induced by maternal hyperthermia and enhanced antioxidant ability with the increased mRNA and protein expressions of metallothionein IV in the embryonic liver. The increased metallothionein IV mRNA expression was due to the reduced DNA methylation and increased histone 3 lysine 9 acetylation of the metallothionein IV promoter regardless of zinc source. These data demonstrate that maternal dietary zinc addition as an epigenetic modifier could protect the offspring embryonic development against maternal heat stress via enhancing the epigenetic-activated antioxidant ability.

Early zebrafish development: It’s in the maternal genes

PubMed Central

Abrams, Elliott W.; Mullins, Mary C.

2009-01-01

Summary The earliest stages of embryonic development in all animals examined rely on maternal gene products that are generated during oogenesis and supplied to the egg. The period of maternal control of embryonic development varies among animals according to the onset of zygotic transcription and the persistence of maternal gene products. This maternal regulation has been little studied in vertebrates, due to the difficulty in manipulating maternal gene function and lack of basic molecular information. However, recent maternal-effect screens in the zebrafish have generated more than 40 unique mutants that are providing new molecular entry points to the maternal control of early vertebrate development. Here we discuss recent studies of 12 zebrafish mutant genes that illuminate the maternal molecular controls on embryonic development, including advances in the regulation of animal-vegetal polarity, egg activation, cleavage development, body plan formation, tissue morphogenesis, microRNA function and germ cell development. PMID:19608405

EXTRA-EMBRYONIC-SPECIFIC IMPRINTED EXPRESSION IS RESTRICTED TO DEFINED LINEAGES IN THE POST-IMPLANTATION EMBRYO

PubMed Central

Hudson, Quanah J.; Seidl, Christine I.M.; Kulinski, Tomasz M.; Huang, Ru; Warczok, Katarzyna E.; Bittner, Romana; Bartolomei, Marisa S.; Barlow, Denise P.

2011-01-01

A subset of imprinted genes in the mouse have been reported to show imprinted expression that is restricted to the placenta, a short-lived extra-embryonic organ. Notably these so-called 'placental-specific' imprinted genes are expressed from both parental alleles in embryo and adult tissues. The placenta is an embryonic-derived organ that is closely associated with maternal tissue and as a consequence, maternal contamination can be mistaken for maternal-specific imprinted expression. The complexity of the placenta, which arises from multiple embryonic lineages, poses additional problems in accurately assessing allele-specific repressive epigenetic modifications in genes that also show lineage-specific silencing in this organ. These problems require that extra evidence be obtained to support the imprinted status of genes whose imprinted expression is restricted to the placenta. We show here that the extra-embryonic visceral yolk sac (VYS), a nutritive membrane surrounding the developing embryo, shows a similar 'extra-embryonic-lineage-specific' pattern of imprinted expression. We present an improved enzymatic technique for separating the bilaminar VYS and show that this pattern of imprinted expression is restricted to the endoderm layer. Finally, we show that VYS 'extra-embryonic-lineage-specific' imprinted expression is regulated by DNA methylation in a similar manner as shown for genes showing multi-lineage imprinted expression in extra-embryonic, embryonic and adult tissues. These results show that the VYS is an improved model for studying the epigenetic mechanisms regulating extra-embryonic-lineage-specific imprinted expression. PMID:21354127

Expression and regulation of glucocorticoid-induced leucine zipper in the developing anterior pituitary gland.

PubMed

Ellestad, Laura E; Malkiewicz, Stefanie A; Guthrie, H David; Welch, Glenn R; Porter, Tom E

2009-02-01

The expression profile of glucocorticoid-induced leucine zipper (GILZ) in the anterior pituitary during the second half of embryonic development in the chick is consistent with in vivo regulation by circulating corticosteroids. However, nothing else has been reported about the presence of GILZ in the neuroendocrine system. We sought to characterize expression and regulation of GILZ in the chicken embryonic pituitary gland and determine the effect of GILZ overexpression on anterior pituitary hormone levels. Pituitary GILZ mRNA levels increased during embryogenesis to a maximum on the day of hatch, and decreased through the first week after hatch. GILZ expression was rapidly upregulated by corticosterone in embryonic pituitary cells. To determine whether GILZ regulates hormone gene expression in the developing anterior pituitary, we overexpressed GILZ in embryonic pituitary cells and measured mRNA for the major pituitary hormones. Exogenous GILZ increased prolactin mRNA above basal levels, but not as high as that in corticosterone-treated cells, indicating that GILZ may play a small role in lactotroph differentiation. The largest effect we observed was a twofold increase in FSH beta subunit in cells transfected with GILZ but not treated with corticosterone, suggesting that GILZ may positively regulate gonadotroph development in a manner not involving glucocorticoids. In conclusion, this is the first report to characterize avian GILZ and examine its regulation in the developing neuroendocrine system. We have shown that GILZ is upregulated by glucocorticoids in the embryonic pituitary gland and may regulate expression of several pituitary hormones.

4D Subject-Specific Inverse Modeling of the Chick Embryonic Heart Outflow Tract Hemodynamics

PubMed Central

Goenezen, Sevan; Chivukula, Venkat Keshav; Midgett, Madeline; Phan, Ly; Rugonyi, Sandra

2015-01-01

Blood flow plays a critical role in regulating embryonic cardiac growth and development, with altered flow leading to congenital heart disease. Progress in the field, however, is hindered by a lack of quantification of hemodynamic conditions in the developing heart. In this study, we present a methodology to quantify blood flow dynamics in the embryonic heart using subject-specific computational fluid dynamics (CFD) models. While the methodology is general, we focused on a model of the chick embryonic heart outflow tract (OFT), which distally connects the heart to the arterial system, and is the region of origin of many congenital cardiac defects. Using structural and Doppler velocity data collected from optical coherence tomography (OCT), we generated 4D (3D + time) embryo-specific CFD models of the heart OFT. To replicate the blood flow dynamics over time during the cardiac cycle, we developed an iterative inverse-method optimization algorithm, which determines the CFD model boundary conditions such that differences between computed velocities and measured velocities at one point within the OFT lumen are minimized. Results from our developed CFD model agree with previously measured hemodynamics in the OFT. Further, computed velocities and measured velocities differ by less than 15% at locations that were not used in the optimization, validating the model. The presented methodology can be used in quantifications of embryonic cardiac hemodynamics under normal and altered blood flow conditions, enabling an in depth quantitative study of how blood flow influences cardiac development. PMID:26361767

CD146(+) cells are essential for kidney vasculature development.

PubMed

Halt, Kimmo J; Pärssinen, Heikki E; Junttila, Sanna M; Saarela, Ulla; Sims-Lucas, Sunder; Koivunen, Peppi; Myllyharju, Johanna; Quaggin, Susan; Skovorodkin, Ilya N; Vainio, Seppo J

2016-08-01

The kidney vasculature is critical for renal function, but its developmental assembly mechanisms remain poorly understood and models for studying its assembly dynamics are limited. Here, we tested whether the embryonic kidney contains endothelial cells (ECs) that are heterogeneous with respect to VEGFR2/Flk1/KDR, CD31/PECAM, and CD146/MCAM markers. Tie1Cre;R26R(YFP)-based fate mapping with a time-lapse in embryonic kidney organ culture successfully depicted the dynamics of kidney vasculature development and the correlation of the process with the CD31(+) EC network. Depletion of Tie1(+) or CD31(+) ECs from embryonic kidneys, with either Tie1Cre-induced diphtheria toxin susceptibility or cell surface marker-based sorting in a novel dissociation and reaggregation technology, illustrated substantial EC network regeneration. Depletion of the CD146(+) cells abolished this EC regeneration. Fate mapping of green fluorescent protein (GFP)-marked CD146(+)/CD31(-) cells indicated that they became CD31(+) cells, which took part in EC structures with CD31(+) wild-type ECs. EC network development depends on VEGF signaling, and VEGF and erythropoietin are expressed in the embryonic kidney even in the absence of any external hypoxic stimulus. Thus, the ex vivo embryonic kidney culture models adopted here provided novel ways for targeting renal EC development and demonstrated that CD146(+) cells are critical for kidney vasculature development. Copyright © 2016 International Society of Nephrology. All rights reserved.

Gas exchange in avian embryos and hatchlings.

PubMed

Mortola, Jacopo P

2009-08-01

The avian egg has been proven to be an excellent model for the study of the physical principles and the physiological characteristics of embryonic gas exchange. In recent years, it has become a model for the studies of the prenatal development of pulmonary ventilation, its chemical control and its interaction with extra-pulmonary gas exchange. Differently from mammals, in birds the initiation of pulmonary ventilation and the transition from diffusive to convective gas exchange are gradual and slow-occurring events amenable to detailed investigations. The absence of the placenta and of the mother permits the study of the mechanisms of embryonic adaptation to prenatal perturbations in a way that would be impossible with mammalian preparations. First, this review summarises the general aspects of the natural history of the avian egg that are pertinent to embryonic metabolism, growth and gas exchange and the characteristics of the structures participating in gas exchange. Then, the review focuses on the embryonic development of pulmonary ventilation, its regulation in relation to the embryo's environment and metabolic state, the effects that acute or sustained changes in embryonic temperature or oxygenation can have on growth, metabolism and ventilatory control.

Somatic Donor Cell Type Correlates with Embryonic, but Not Extra-Embryonic, Gene Expression in Postimplantation Cloned Embryos

PubMed Central

Inoue, Kimiko; Ogura, Atsuo

2013-01-01

The great majority of embryos generated by somatic cell nuclear transfer (SCNT) display defined abnormal phenotypes after implantation, such as an increased likelihood of death and abnormal placentation. To gain better insight into the underlying mechanisms, we analyzed genome-wide gene expression profiles of day 6.5 postimplantation mouse embryos cloned from three different cell types (cumulus cells, neonatal Sertoli cells and fibroblasts). The embryos retrieved from the uteri were separated into embryonic (epiblast) and extraembryonic (extraembryonic ectoderm and ectoplacental cone) tissues and were subjected to gene microarray analysis. Genotype- and sex-matched embryos produced by in vitro fertilization were used as controls. Principal component analysis revealed that whereas the gene expression patterns in the embryonic tissues varied according to the donor cell type, those in extraembryonic tissues were relatively consistent across all groups. Within each group, the embryonic tissues had more differentially expressed genes (DEGs) (>2-fold vs. controls) than did the extraembryonic tissues (P<1.0×10–26). In the embryonic tissues, one of the common abnormalities was upregulation of Dlk1, a paternally imprinted gene. This might be a potential cause of the occasional placenta-only conceptuses seen in SCNT-generated mouse embryos (1–5% per embryos transferred in our laboratory), because dysregulation of the same gene is known to cause developmental failure of embryos derived from induced pluripotent stem cells. There were also some DEGs in the extraembryonic tissues, which might explain the poor development of SCNT-derived placentas at early stages. These findings suggest that SCNT affects the embryonic and extraembryonic development differentially and might cause further deterioration in the embryonic lineage in a donor cell-specific manner. This could explain donor cell-dependent variations in cloning efficiency using SCNT. PMID:24146866

Epidermal differentiation in embryos of the tuatara Sphenodon punctatus (Reptilia, Sphenodontidae) in comparison with the epidermis of other reptiles.

PubMed

Alibardi, L; Gill, B J

2007-07-01

Studying the epidermis in primitive reptiles can provide clues regarding evolution of the epidermis during land adaptation in vertebrates. With this aim, the development of the skin of the relatively primitive reptile Sphenodon punctatus in representative embryonic stages was studied by light and electron microscopy and compared with that of other reptiles previously studied. The dermis organizes into a superficial and deep portion when the epidermis starts to form the first layers. At embryonic stages comparable with those of lizards, only one layer of the inner periderm is formed beneath the outer periderm. This also occurs in lizards and snakes so far studied. The outer and inner periderm form the embryonic epidermis and accumulate thick, coarse filaments (25-30 nm thick) and sparse alpha-keratin filaments as in other reptiles. Beneath the embryonic epidermis an oberhautchen and beta-cells form small horny tips that represent overlapping borders along the margin of beta-cells that overlap other beta-cells (in a tile-like arrangement). The tips resemble those of agamine lizards but at a small scale, forming a lamellate-spinulated pattern as previously described in adult epidermis. The embryonic epidermis matures by the dispersion of coarse filaments among keratin at the end of embryonic development and is shed around hatching. The presence of these matrix organelles in the embryonic epidermis of this primitive reptile further indicates that amniote epidermis acquired interkeratin matrix proteins early for land adaptation. Unlike the condition in lizards and snakes, a shedding complex is not formed in the epidermis of embryonic S. punctatus that is like that of the adult. Therefore, as in chelonians and crocodilians, the epidermis of S. punctatus also represents an initial stage that preceded the evolution of the shedding complex for moulting.

Epidermal differentiation in embryos of the tuatara Sphenodon punctatus (Reptilia, Sphenodontidae) in comparison with the epidermis of other reptiles

PubMed Central

Alibardi, L; Gill, B J

2007-01-01

Studying the epidermis in primitive reptiles can provide clues regarding evolution of the epidermis during land adaptation in vertebrates. With this aim, the development of the skin of the relatively primitive reptile Sphenodon punctatus in representative embryonic stages was studied by light and electron microscopy and compared with that of other reptiles previously studied. The dermis organizes into a superficial and deep portion when the epidermis starts to form the first layers. At embryonic stages comparable with those of lizards, only one layer of the inner periderm is formed beneath the outer periderm. This also occurs in lizards and snakes so far studied. The outer and inner periderm form the embryonic epidermis and accumulate thick, coarse filaments (25–30 nm thick) and sparse alpha-keratin filaments as in other reptiles. Beneath the embryonic epidermis an oberhautchen and beta-cells form small horny tips that represent overlapping borders along the margin of beta-cells that overlap other beta-cells (in a tile-like arrangement). The tips resemble those of agamine lizards but at a small scale, forming a lamellate-spinulated pattern as previously described in adult epidermis. The embryonic epidermis matures by the dispersion of coarse filaments among keratin at the end of embryonic development and is shed around hatching. The presence of these matrix organelles in the embryonic epidermis of this primitive reptile further indicates that amniote epidermis acquired interkeratin matrix proteins early for land adaptation. Unlike the condition in lizards and snakes, a shedding complex is not formed in the epidermis of embryonic S. punctatus that is like that of the adult. Therefore, as in chelonians and crocodilians, the epidermis of S. punctatus also represents an initial stage that preceded the evolution of the shedding complex for moulting. PMID:17532799

Implications of Parkinson's disease pathophysiology for the development of cell replacement strategies and drug discovery in neurodegenerative diseases.

PubMed

Pan-Montojo, Francisco; Funk, Richard H W

2012-11-01

Parkinson's disease (PD) is a progressive neurodegenerative disorder traditionally characterized by the loss of dopaminergic neurons in the substantia nigra (SN) at the midbrain. The potential use of adult or embryonic stem cells, induced pluriputent stem (iPS) cells and endogenous neurogenesis in cell replacement strategies has lead to numerous studies and clinical trials in this direction. It is now possible to differentiate stem cells into dopaminergic neurons in vitro and clinical trials have shown an improvement in PD-related symptoms after intra-striatal embryonic transplants and acceptable cell survival rates on the mid term. However, clinical improvement is transitory and associated with a strong placebo effect. Interestingly, recent pathological studies in PD patients who received embryonic stem cells show that in PD patients, grafted neurons show PD-related pathology. In this manuscript we review the latest findings regarding PD pathophysiology and give an outlook on the implications of these findings in how cell replacement strategies for PD treatment should be tested. These include changes in the type of animal models used, the preparation/conditioning of the cells before intracerebral injection, specially regarding backbone chronic diseases in iPS cells and determining the optimal proliferation, survival, differentiation and migration capacity of the grafted cells.

Protein kinase A inhibitor, H89, significantly enhances survival rate of dissociated human embryonic stem cells following cryopreservation.

PubMed

Zhang, Liang; Xu, Yanqing; Xu, Jiandong; Wei, Yuping; Xu, Xia

2016-10-01

Human embryonic stem cells (hESCs) have huge potential for establishment of disease models and for treating degenerative diseases. However, the extremely low survival level of dissociated hESCs following cryopreservation is been a tremendous problem to allow for their rapid expansion, genetic manipulation and future medical applications. In this study, we have aimed to develop an efficient strategy to improve survival of dissociated hESCs after cryopreservation. Human embryonic stem cells (H9 line), dissociated into single cells, were cryopreserved using the slow-freezing method. Viable cells and their colony numbers in culture after cryopreservation were evaluated when treated with protein kinase A inhibitor H89. Western blotting was carried out to investigate mechanisms of low survival levels of dissociated hESCs following cryopreservation. Immunofluorescence, reverse transcription-polymerase chain reaction (RT-PCR), in vitro and in vivo differentiation were performed to testify to pluripotency and differentiation ability of hte cryopreserved cells treated with H89. H89 significantly improved survival level of dissociated hESCs after cryopreservation through ROCK inhibition. H89-treated cells still maintained their pluripotency and differentiation capacity. This new approach for cryopreservation of single hESCs, using H89, can promote potential use of hESCs in regenerative medicine in the future. © 2016 John Wiley & Sons Ltd.

Toxicity evaluation of β-diketone antibiotics on the development of embryo-larval zebrafish (Danio rerio).

PubMed

Wang, Huili; Che, Baoguang; Duan, Ailian; Mao, Jingwen; Dahlgren, Randy A; Zhang, Minghua; Zhang, Hongqin; Zeng, Aibing; Wang, Xuedong

2014-10-01

This study evaluated the effects of β-diketone antibiotics (DKAs) on the development of embryo-larval zebrafish (Danio rerio). When exposure to DKAs, developmental malformations, such as hatching delay, curved body axis, pericardial edema, uninflated swim bladder and yolk sac edema, were observed at 120 h postfertilization (hpf). The estimated 120 hpf nominal concentrations of no observed effect concentration and lowest observed effect concentration for DKAs were 18.75 and 37.50 mg/L, respectively, suggesting that DKAs have much lower toxicity than other persistent pollutants. Following DKA exposure, embryonic heart rates were significantly reduced as compared to the controls at 48 and 60 hpf. The peak bending motion frequency appeared 1 h earlier than in control embryos. The 2.34 and 9.38-mg/L treatment groups had a higher basal swim rate than control groups at 120 hpf in both light and light-to-dark photoperiod experiments. The occurrence of high speed swim rates was enhanced approximately threefold to sevenfold in the 2.34 and 9.38 mg/L treatments compared to the control. Glutathione (GSH) concentrations in the 2.34 and 9.38-mg/L treatments were significantly higher than the control at 72 hpf, suggesting that GSH production was induced at the end of the hatching period. When exposed to DKAs, zebrafish superoxide dismutase enzyme (SOD) activities were significantly inhibited in the early embryonic period, demonstrating that the clearing ability in zebrafish was lower than the generation rate of free radicals. In summary, the combined DKAs were developmentally toxic to zebrafish in their early life stages and had the ability to impair individual behaviors that are of great importance in the assessment of their ecological fitness. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

Developmental competence of Dromedary camel (Camelus dromedarius) oocytes selected using brilliant cresyl blue staining.

PubMed

Fathi, Mohamed; Ashry, Mohamed; Salama, Ali; Badr, Magdy R

2017-08-01

The objectives of the present studies were to investigate the developmental capacity of dromedary camel oocytes selected by brilliant cresyl blue (BCB) staining and to investigate the expression of select transcripts in germinal vesicle (GV) stage oocytes. These transcripts included BMP15 and GDF9 as important transcripts for folliculogenesis and oocyte development, Zar1 and Mater as maternal transcripts required for embryonic development, Cyclin B1 and CDK1 as cell cycle regulators and Oct4 and STAT3 as transcription factors. Dromedary camel oocytes were retrieved from ovaries collected at a local slaughterhouse. After exposure to BCB staining, cumulus-oocyte complexes (COCs) from BCB+, BCB- and control (selected based on morphological criteria) groups were subjected to in vitro maturation, in vitro fertilization and in vitro culture. For gene expression studies, after BCB staining cumulus cells were stripped off and the completely denuded GV stage oocytes were used for RT-PCR analysis of selected transcripts. BCB+ oocytes showed higher maturation, and fertilization rates compared with BCB- and control groups. Indices of early embryonic development, namely, cleavage at 48 hours post insemination (hpi), and development to morula at day 5 and day 7 blastocyst rates were also significantly higher in the BCB+ group. RT-PCR revealed a higher expression of BMP15, GDF9, Zar1, Mater, Cyclin B1, CDK1, OCT4 and STAT3 in good quality oocytes that stained positively for BCB (BCB+). Collectively, results provide novel information about the use of BCB screening for selecting good quality oocytes to improve in vitro embryo production in the dromedary camel.

Mechanisms of Microwave Induced Damage in Biologic Materials

DTIC Science & Technology

1992-10-01

that low level electromagnetic fields can cause developmental abnormalities in early stages of chick embryo development . In studies of the effects of...early embryonic development has led to a great deal of speculation about the safety of environmental exposure to such fields. Power lines, household...capable of covalent binding to embryonic or fetal macromolecules and nucleic acids, disrupting normal development . Individuals with low levels of

Hypoxia delays hematopoiesis: retention of embryonic hemoglobin and erythrocytes in larval rainbow trout, Oncorhynchus mykiss, during chronic hypoxia exposure.

PubMed

Bianchini, Kristin; Wright, Patricia A

2013-12-01

In rainbow trout development, a switch occurs from high-affinity embryonic hemoglobin (Hb) and round, embryonic erythrocytes to lower-affinity adult Hb and oval, adult erythrocytes. Our study investigated the early ontogeny of rainbow trout blood properties and the hypoxia response. We hypothesized that hypoxia exposure would delay the ontogenetic turnover of Hb and erythrocytes because retention of high-affinity embryonic Hb would facilitate oxygen loading. To test this hypothesis we developed a method of efficiently extracting blood from individual embryos and larvae and optimized several techniques for measuring hematological parameters on microliter (0.5-2.0 μl) blood samples. In chronic hypoxia (30% of oxygen saturation), stage-matched embryos and larvae possessed half the Hb concentration, erythrocyte counts and hematocrit observed in normoxia. Hypoxia-reared larvae also had threefold to sixfold higher mRNA expression of the embryonic Hb α-1, β-1 and β-2 subunits relative to stage-matched normoxia-reared larvae. Furthermore, in hypoxia, the round embryonic erythrocytic shape persisted into later developmental stages. Despite these differences, Hb-oxygen affinity (P50), cooperativity and the Root effect were unaltered in hypoxia-reared O. mykiss. The data support our hypothesis that chronic hypoxia delays the ontogenetic turnover of Hb and erythrocytes, but without the predicted functional consequences (i.e. higher than expected P50). These results also suggest that the Hb-oxygen affinity is protected during development in chronic hypoxia to favor oxygen unloading at the tissues. We conclude that in early trout development, the blood-oxygen transport system responds very differently to chronic hypoxia relative to adults, possibly because respiration depends relatively more on oxygen diffusion than convection.

Functional optical coherence tomography for live dynamic analysis of mouse embryonic cardiogenesis

NASA Astrophysics Data System (ADS)

Wang, Shang; Lopez, Andrew L.; Larina, Irina V.

2018-02-01

Blood flow, heart contraction, and tissue stiffness are important regulators of cardiac morphogenesis and function during embryonic development. Defining how these factors are integrated is critically important to advance prevention, diagnostics, and treatment of congenital heart defects. Mammalian embryonic development is taking place deep within the female body, which makes cardiodynamic imaging and analysis during early developmental stages in humans inaccessible. With thousands of mutant lines available and well-established genetic manipulation tools, mouse is a great model to understand how biomechanical factors are integrated with molecular pathways to regulate cardiac function and development. Dynamic imaging and quantitative analysis of the biomechanics of live mouse embryos have become increasingly important, which demands continuous advancements in imaging techniques and live assessment approaches. This has been one of the major drives to keep pushing the frontier of embryonic imaging for better resolution, higher speed, deeper penetration, and more diverse and effective contrasts. Optical coherence tomography (OCT) has played a significant role in addressing such demands, and its features in non-labeling imaging, 3D capability, a large working distance, and various functional derivatives allow OCT to cover a number of specific applications in embryonic imaging. Recently, our group has made several technical improvements in using OCT to probe the biomechanical aspects of live developing mouse embryos at early stages. These include the direct volumetric structural and functional imaging of the cardiodynamics, four-dimensional quantitative Doppler imaging and analysis of the cardiac blood flow, and fourdimensional blood flow separation from the cardiac wall tissue in the beating embryonic heart. Here, we present a short review of these studies together with brief descriptions of the previous work that demonstrate OCT as a valuable and useful imaging tool for the research in developmental cardiology.

Enhancement of cardiomyogenesis in stem cells by low intensity pulsed ultrasound

NASA Astrophysics Data System (ADS)

Teo, Ailing; Morshedi, Amir; Wang, Jen-Chieh; Lim, Mayasari; Zhou, Yufeng

2017-03-01

Low intensity pulsed ultrasound (LIPUS) has been shown to enhance bone and cartilage regeneration from stem cells. Gene expression of angiotensin II type 1 (AT1) receptor can be increased in LIPUS-treated osteoblasts. The AT1 receptor is a known mechanoreceptor in cardiomyocytes. It suggests that LIPUS may enhance cardiomyogenesis via mechanotransduction by increasing AT1 expression. Murine embryonic stem cells (ESCs) were treated daily by 10-min 1MHz LIPUS at spatial-average temporal-peak acoustic intensities of 30 mW/cm2 and 300 mW/cm2 in both continuous and pulsed wave (20% duty cycle) for 10 days. Polymerase chain reaction (PCR), immunocytochemistry, and beating rate were used to evaluate the cardiac viability quantitatively. After the treatment of LIPUS, beating rate of contractile areas and cardiac gene expression, such as α- and β-myosin heavy chain, were improved. Furthermore, no deleterious effects to the development of cardiac proteins were observed. All results suggest that LIPUS stimulation has the capacity of enhancing cardiomyogenesis from embryonic stem cells. With the benefit and the ease in incorporating LIPUS into various culture platforms, LIPUS has the potential to produce cardiomyocytes for clinical use in the future.

Histology Atlas of the Developing Mouse Hepatobiliary System with Emphasis on Embryonic Days 9.5-18.5

PubMed Central

Crawford, Laura Wilding; Foley, Julie F.; Elmore, Susan A.

2012-01-01

Animal model phenotyping, in utero exposure toxiciy studies, and investigation into causes of embryonic, fetal, or perinatal deaths have required pathologists to recognize and diagnose developmental disorders in spontaneous and engineered mouse models of disease. In mammals, the liver is the main site of hematopoiesis during fetal development, has endocrine and exocrine functions important for maintaining homeostasis in fetal and adult life; and performs other functions including waste detoxification, production and removal of glucose, glycogen storage, triglyceride and fatty acid processing, and serum protein production. Due to its role in many critical functions, alterations in the size, morphology, or function(s) of the liver often lead to embryonic lethality. Many publications and websites describe individual aspects of hepatobiliary development at defined stages. However, no single resource provides a detailed histological evaluation of H&E-stained sections of the developing murine liver and biliary systems using high-magnification and high-resolution color images. The work herein provides a histology atlas of hepatobiliary development between embryonic days 9.5-18.5. Although the focus of this work is normal hepatobiliary development, common defects in liver development are also described as a reference for pathologists who may be asked to phenotype mice with congenital, inherited, or treatment-related hepatobiliary defects. PMID:20805319

Stage-dependent and locus-specific role of histone demethylase Jumonji D3 (JMJD3) in the embryonic stages of lung development.

PubMed

Li, Qingtian; Wang, Helen Y; Chepelev, Iouri; Zhu, Qingyuan; Wei, Gang; Zhao, Keji; Wang, Rong-Fu

2014-07-01

Histone demethylases have emerged as important players in developmental processes. Jumonji domain containing-3 (Jmjd3) has been identified as a key histone demethylase that plays a critical role in the regulation of gene expression; however, the in vivo function of Jmjd3 in embryonic development remains largely unknown. To this end, we generated Jmjd3 global and conditional knockout mice. Global deletion of Jmjd3 induces perinatal lethality associated with defective lung development. Tissue and stage-specific deletion revealed that Jmjd3 is dispensable in the later stage of embryonic lung development. Jmjd3 ablation downregulates the expression of genes critical for lung development and function, including AQP-5 and SP-B. Jmjd3-mediated alterations in gene expression are associated with locus-specific changes in the methylation status of H3K27 and H3K4. Furthermore, Jmjd3 is recruited to the SP-B promoter through interactions with the transcription factor Nkx2.1 and the epigenetic protein Brg1. Taken together, these findings demonstrate that Jmjd3 plays a stage-dependent and locus-specific role in the mouse lung development. Our study provides molecular insights into the mechanisms by which Jmjd3 regulates target gene expression in the embryonic stages of lung development.

Enzymatic Metabolism of Vitamin A in Developing Vertebrate Embryos

PubMed Central

Metzler, Melissa A.; Sandell, Lisa L.

2016-01-01

Embryonic development is orchestrated by a small number of signaling pathways, one of which is the retinoic acid (RA) signaling pathway. Vitamin A is essential for vertebrate embryonic development because it is the molecular precursor of the essential signaling molecule RA. The level and distribution of RA signaling within a developing embryo must be tightly regulated; too much, or too little, or abnormal distribution, all disrupt embryonic development. Precise regulation of RA signaling during embryogenesis is achieved by proteins involved in vitamin A metabolism, retinoid transport, nuclear signaling, and RA catabolism. The reversible first step in conversion of the precursor vitamin A to the active retinoid RA is mediated by retinol dehydrogenase 10 (RDH10) and dehydrogenase/reductase (SDR family) member 3 (DHRS3), two related membrane-bound proteins that functionally activate each other to mediate the interconversion of retinol and retinal. Alcohol dehydrogenase (ADH) enzymes do not contribute to RA production under normal conditions during embryogenesis. Genes involved in vitamin A metabolism and RA catabolism are expressed in tissue-specific patterns and are subject to feedback regulation. Mutations in genes encoding these proteins disrupt morphogenesis of many systems in a developing embryo. Together these observations demonstrate the importance of vitamin A metabolism in regulating RA signaling during embryonic development in vertebrates. PMID:27983671

How the embryonic chick brain twists.

PubMed

Chen, Zi; Guo, Qiaohang; Dai, Eric; Forsch, Nickolas; Taber, Larry A

2016-11-01

During early development, the tubular embryonic chick brain undergoes a combination of progressive ventral bending and rightward torsion, one of the earliest organ-level left-right asymmetry events in development. Existing evidence suggests that bending is caused by differential growth, but the mechanism for the predominantly rightward torsion of the embryonic brain tube remains poorly understood. Here, we show through a combination of in vitro experiments, a physical model of the embryonic morphology and mechanics analysis that the vitelline membrane (VM) exerts an external load on the brain that drives torsion. Our theoretical analysis showed that the force is of the order of 10 micronewtons. We also designed an experiment to use fluid surface tension to replace the mechanical role of the VM, and the estimated magnitude of the force owing to surface tension was shown to be consistent with the above theoretical analysis. We further discovered that the asymmetry of the looping heart determines the chirality of the twisted brain via physical mechanisms, demonstrating the mechanical transfer of left-right asymmetry between organs. Our experiments also implied that brain flexure is a necessary condition for torsion. Our work clarifies the mechanical origin of torsion and the development of left-right asymmetry in the early embryonic brain. © 2016 The Author(s).

Ca2+ signalling and early embryonic patterning during zebrafish development.

PubMed

Webb, Sarah E; Miller, Andrew L

2007-09-01

1. It has been proposed that Ca2+ signalling, in the form of pulses, waves and steady gradients, may play a crucial role in key pattern-forming events during early vertebrate development. 2. With reference to the embryo of the zebrafish (Danio rerio), herein we review the Ca2+ transients reported from the cleavage to segmentation periods. This time-window includes most of the major pattern-forming events of early development, which transform a single-cell zygote into a complex multicellular embryo with established primary germ layers and body axes. 3. Data are presented to support our proposal that intracellular Ca2+ waves are an essential feature of embryonic cytokinesis and that propagating intercellular Ca2+ waves (both long and short range) may play a crucial role in: (i) the establishment of the embryonic periderm and the coordination of cell movements during epiboly, convergence and extension; (ii) the establishment of the basic embryonic axes and germ layers; and (iii) definition of the morphological boundaries of specific tissue domains and embryonic structures, including future organ anlagen. 4. The potential downstream targets of these Ca2+ transients are also discussed, as well as how they may integrate with other pattern-forming signalling pathways known to modulate early developmental events.

The Evolutionary Economics of Embryonic-Sac Fluids in Squamate Reptiles.

PubMed

Bonnet, Xavier; Naulleau, Guy; Shine, Richard

2017-03-01

The parchment-shelled eggs of squamate reptiles take up substantial water from the nest environment, enabling the conversion of yolk into neonatal tissue and buffering the embryo against the possibility of subsequent dry weather. During development, increasing amounts of water are stored in the embryonic sacs (i.e., membranes around the embryo: amnion, allantois, and chorion). The evolution of viviparity (prolonged uterine retention of developing embryos) means that embryonic-sac fluid storage now imposes a cost (increased maternal burdening), confers less benefit (because the mother buffers fetal water balance), and introduces a potential conflict among uterine siblings (for access to finite water supplies). Our data on nine species of squamate reptiles and published information on three species show that the embryonic-sac fluids comprise around 33% of neonatal mass in viviparous species versus 94% in full-term eggs of oviparous squamates. Data on parturition in 149 vipers (Vipera aspis, a viviparous species) show that larger offspring store more fluids in their fetal sacs and that an increase in litter size is associated with a decrease in fluid-sac mass per offspring. Overall, the evolutionary transition from oviparity to viviparity may have substantially altered selective forces on offspring packaging and created competition among offspring for access to water reserves during embryonic development.

Embryonic development of Ampheres leucopheus and Iporangaia pustulosa (Arachnida: Opiliones: Gonyleptidae).

PubMed

Gnaspini, Pedro; Lerche, Cristiano Frederico

2010-09-15

The first studies concerning the embryonic development of harvestmen started in the late 19th century, and focused mostly on holarctic species, and only three species of the suborder Laniatores (the largest, among the four suborders considered presently) were studied. Moreover, the last studies on embryology of harvestmen were made during the late 1970s. This study focused on the embryonic development of Ampheres leucopheus (Gonyleptidae, Caelopyginae) and Iporangaia pustulosa (Gonyleptidae, Progonyleptoidellinae). The embryonic development was followed in the field, by taking daily photographs of different eggs during about 2 months. When laid, eggs of A. leucopheus and I. pustulosa have approximately 1.13 and 1.30 mm in diameter, respectively, and the second is embedded in a large amount of mucus. The eggs grow, mainly due to water absorption at the beginning of the process, and they reach a diameter of about 1.35 and 1.59 mm, respectively, close to hatching. It took, respectively, 29-56 days and 35-66 days from egg laying to hatching. For the description of the embryonic development, we use photographs from the field, SEM micrographs, and histological analysis. This allowed us, for instance, to document the progression of structures and pigmentation directly from live embryos in the field, and to record microstructures, such as the presence of perforations in the cuticle of the embryo in the place where eyes are developing. Yet, contrary to what was expected in the literature, we record an egg tooth in one of the studied laniatoreans. (c) 2010 Wiley-Liss, Inc.

Vacuolar status and water relations in embryonic axes of recalcitrant Aesculus hippocastanum seeds during stratification and early germination.

PubMed

Obroucheva, Natalie V; Lityagina, Snezhana V; Novikova, Galina V; Sin'kevich, Irina A

2012-01-01

In tropical recalcitrant seeds, their rapid transition from shedding to germination at high hydration level is of physiological interest but difficult to study because of the time constraint. In recalcitrant horse chestnut seeds produced in central Russia, this transition is much longer and extends through dormancy and dormancy release. This extended time period permits studies of the water relations in embryonic axes during the long recalcitrant period in terms of vacuolar status and water transport. Horse chestnut (Aesculus hippocastanum) seeds sampled in Moscow were stratified in cold wet sand for 4 months. Vacuole presence and development in embryonic axes were examined by vital staining, light and electron microscopy. Aquaporins and vacuolar H(+)-ATPase were identified immunochemically. Water channel operation was tested by water inflow rate. Vacuolar acid invertase was estimated in terms of activity and electrophoretic properties. Throughout the long recalcitrant period after seed shedding, cells of embryonic axes maintained active vacuoles and a high water content. Preservation of enzyme machinery in vacuoles was evident from retention of invertase activity, substrate specificity, molecular mass and subunit composition. Plasmalemma and tonoplast aquaporins and the E subunit of vacuolar H(+)-ATPase were also present. In non-dormant seeds prior to growth initiation, vacuoles enlarged at first in hypocotyls, and then in radicles, with their biogenesis being similar. Vacuolation was accompanied by increasing invertase activity, leading to sugar accumulation and active osmotic functioning. After growth initiation, vacuole enlargement was favoured by enhanced water inflow through water channels formed by aquaporins. Maintenance of high water content and desiccation sensitivity, as well as preservation of active vacuoles in embryonic axes after shedding, can be considered a specific feature of recalcitrant seeds, overlooked when studying tropical recalcitrants due to the short duration. The retained physiological activity of vacuoles allows them to function rapidly as dormancy is lost and when external conditions permit. Cell vacuolation precedes cell elongation in both hypocotyl and radicle, and provides impetus for rapid germination.

I-SceI-mediated double-strand break does not increase the frequency of homologous recombination at the Dct locus in mouse embryonic stem cells.

PubMed

Fenina, Myriam; Simon-Chazottes, Dominique; Vandormael-Pournin, Sandrine; Soueid, Jihane; Langa, Francina; Cohen-Tannoudji, Michel; Bernard, Bruno A; Panthier, Jean-Jacques

2012-01-01

Targeted induction of double-strand breaks (DSBs) at natural endogenous loci was shown to increase the rate of gene replacement by homologous recombination in mouse embryonic stem cells. The gene encoding dopachrome tautomerase (Dct) is specifically expressed in melanocytes and their precursors. To construct a genetic tool allowing the replacement of Dct gene by any gene of interest, we generated an embryonic stem cell line carrying the recognition site for the yeast I-SceI meganuclease embedded in the Dct genomic segment. The embryonic stem cell line was electroporated with an I-SceI expression plasmid, and a template for the DSB-repair process that carried sequence homologies to the Dct target. The I-SceI meganuclease was indeed able to introduce a DSB at the Dct locus in live embryonic stem cells. However, the level of gene targeting was not improved by the DSB induction, indicating a limited capacity of I-SceI to mediate homologous recombination at the Dct locus. These data suggest that homologous recombination by meganuclease-induced DSB may be locus dependent in mammalian cells.

A structure-based extracellular matrix expansion mechanism of fibrous tissue growth.

PubMed

Kalson, Nicholas S; Lu, Yinhui; Taylor, Susan H; Starborg, Tobias; Holmes, David F; Kadler, Karl E

2015-05-20

Embryonic growth occurs predominately by an increase in cell number; little is known about growth mechanisms later in development when fibrous tissues account for the bulk of adult vertebrate mass. We present a model for fibrous tissue growth based on 3D-electron microscopy of mouse tendon. We show that the number of collagen fibrils increases during embryonic development and then remains constant during postnatal growth. Embryonic growth was explained predominately by increases in fibril number and length. Postnatal growth arose predominately from increases in fibril length and diameter. A helical crimp structure was established in embryogenesis, and persisted postnatally. The data support a model where the shape and size of tendon is determined by the number and position of embryonic fibroblasts. The collagen fibrils that these cells synthesise provide a template for postnatal growth by structure-based matrix expansion. The model has important implications for growth of other fibrous tissues and fibrosis.

Expression of the ephrin receptor B2 in the embryonic chicken bursa of Fabricius

USDA-ARS?s Scientific Manuscript database

Chicken B-cells develop in a specific organ, the bursa of Fabricius. To understand the bursal microenvironment guiding B-cell development, previous studies identified ephrin (Eph) receptor B2 (EphB2) gene transcripts in the embryonic bursa. We hypothesize that the EphB2 receptors and their ligands r...

Embryonic domains of the aorta derived from diverse origins exhibit distinct properties that converge into a common phenotype in the adult

PubMed Central

Pfaltzgraff, Elise R.; Shelton, Elaine L.; Galindo, Cristi L.; Nelms, Brian L.; Hooper, Christopher W.; Poole, Stanley D.; Labosky, Patricia A.; Bader, David M.; Reese, Jeff

2014-01-01

Vascular smooth muscle cells (VSMCs) are derived from distinct embryonic origins. Vessels originating from differing smooth muscle cell populations have distinct vascular and pathological properties involving calcification, atherosclerosis, and structural defects such as aneurysm and coarctation. We hypothesized that domains within a single vessel, such as the aorta, vary in phenotype based on embryonic origin. Gene profiling and myographic analyses demonstrated that embryonic ascending and descending aortic domains exhibited distinct phenotypes. In vitro analyses demonstrated that VSMCs from each region were dissimilar in terms of cytoskeletal and migratory properties, and retention of different gene expression patterns. Using the same analysis, we found that these same two domains are indistinguishable in the adult vessel. Our data demonstrate that VSMCs from different embryonic origins are functionally distinct in the embryonic mouse, but converge to assume a common phenotype in the aorta of healthy adults. These findings have fundamental implications for aortic development, function and disease progression. PMID:24508561

Extra-embryonic tissue spreading directs early embryo morphogenesis in killifish

PubMed Central

Reig, Germán; Cerda, Mauricio; Sepúlveda, Néstor; Flores, Daniela; Castañeda, Victor; Tada, Masazumi; Härtel, Steffen; Concha, Miguel L.

2017-01-01

The spreading of mesenchymal-like cell layers is critical for embryo morphogenesis and tissue repair, yet we know little of this process in vivo. Here we take advantage of unique developmental features of the non-conventional annual killifish embryo to study the principles underlying tissue spreading in a simple cellular environment, devoid of patterning signals and major morphogenetic cell movements. Using in vivo experimentation and physical modelling we reveal that the extra-embryonic epithelial enveloping cell layer, thought mainly to provide protection to the embryo, directs cell migration and the spreading of embryonic tissue during early development. This function relies on the ability of embryonic cells to couple their autonomous random motility to non-autonomous signals arising from the expansion of the extra-embryonic epithelium, mediated by cell membrane adhesion and tension. Thus, we present a mechanism of extra-embryonic control of embryo morphogenesis that couples the mechanical properties of adjacent tissues in the early killifish embryo. PMID:28580937

Gonadal Mosaicism Induced by Chemical Treatment of Sperm in Drosophila melanogaster

PubMed Central

Lindsley, Dan L.; Hardy, Robert W.; Ripoll, Pedro; Lindsley, Dart

2016-01-01

Accurate interpretation of forward genetic screens of chromosomes exposed in mature spermatozoa to a mutagenic chemical requires understanding—incomplete to date—of how exposed chromosomes and their replicas proceed through early development stages from the fertilized ovum to establishment of the germline of the treated male’s offspring. We describe a model for early embryonic development and establishment of the germline of Drosophila melanogaster and a model-validating experiment. Our model proposes that, barring repair, DNA strands modified by treatment with alkylating agents are stable and mutagenic. Each replication of an alkylated strand can result in misreplication and a mutant-bearing daughter nucleus. Daughter nuclei thenceforth replicate faithfully and their descendants comprise the embryonic syncytium. Of the 256 nuclei present after the eighth division, several migrate into the polar plasm at the posterior end of the embryo to found the germline. Based upon distribution of descendants of the alkylated strands, the misreplication rate, and the number of nuclei selected as germline progenitors, the frequency of gonadal mosaicism is predictable. Experimentally, we tracked chromosomes 2 and 3 from EMS-treated sperm through a number of generations, to characterize autosomal recessive lethal mutations and infer gonadal genetic content of the sons of treated males. Over 50% of 106 sons bore germlines that were singly, doubly, or triply mosaic for chromosome 2 or chromosome 3. These findings were consistent with our model, assuming a rate of misreplication between 0.65 and 0.80 at each replication of an alkylated strand. Crossing treated males to mismatch-repair-deficient females had no apparent effect on mutation rate. PMID:26163187

Development of mice without Cip/Kip CDK inhibitors

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

Tateishi, Yuki; Matsumoto, Akinobu; Kanie, Tomoharu

2012-10-19

Highlights: Black-Right-Pointing-Pointer Mice lacking Cip/Kip CKIs (p21, p27, and p57) survive until embryonic day 13.5. Black-Right-Pointing-Pointer Proliferation of MEFs lacking all three Cip/Kip CKIs appears unexpectedly normal. Black-Right-Pointing-Pointer CDK2 kinase activity of the triple mutant MEFs is increased in G0 phase. -- Abstract: Timely exit of cells from the cell cycle is essential for proper cell differentiation during embryogenesis. Cyclin-dependent kinase (CDK) inhibitors (CKIs) of the Cip/Kip family (p21, p27, and p57) are negative regulators of cell cycle progression and are thought to be essential for development. However, the extent of functional redundancy among Cip/Kip family members has remained largelymore » unknown. We have now generated mice that lack all three Cip/Kip CKIs (TKO mice) and compared them with those lacking each possible pair of these proteins (DKO mice). We found that the TKO embryos develop normally until midgestation but die around embryonic day (E) 13.5, slightly earlier than p27/p57 DKO embryos. The TKO embryos manifested morphological abnormalities as well as increased rates of cell proliferation and apoptosis in the placenta and lens that were essentially indistinguishable from those of p27/p57 DKO mice. Unexpectedly, the proliferation rate and cell cycle profile of mouse embryonic fibroblasts (MEFs) lacking all three Cip/Kip CKIs did not differ substantially from those of control MEFs. The abundance and kinase activity of CDK2 were markedly increased, whereas CDK4 activity and cyclin D1 abundance were decreased, in both p27/p57 DKO and TKO MEFs during progression from G{sub 0} to S phase compared with those in control MEFs. The extents of the increase in CDK2 activity and the decrease in CDK4 activity and cyclin D1 abundance were greater in TKO MEFs than in p27/p57 DKO MEFs. These results suggest that p27 and p57 play an essential role in mouse development after midgestation, and that p21 plays only an auxiliary role in normal development (although it is thought to be a key player in the response to DNA damage).« less

Targeting Notch, Hedgehog, and Wnt pathways in cancer stem cells: clinical update

PubMed Central

Miele, Lucio; Harris, Pamela Jo; Jeong, Woondong; Bando, Hideaki; Kahn, Michael; Yang, Sherry X.

2015-01-01

During the past decade, cancer stem cells (CSCs) have been increasingly identified in many malignancies. Although the origin and plasticity of these cells remain controversial, tumour heterogeneity and the presence of small populations of cells with stem-like characteristics is established in most malignancies. CSCs display many features of embryonic or tissue stem cells, and typically demonstrate persistent activation of one or more highly conserved signal transduction pathways involved in development and tissue homeostasis, including the Notch, Hedgehog (HH), and Wnt pathways. CSCs generally have slow growth rates and are resistant to chemotherapy and/or radiotherapy. Thus, new treatment strategies targeting these pathways to control stem-cell replication, survival and differentiation are under development. Herein, we provide an update on the latest advances in the clinical development of such approaches, and discuss strategies for overcoming CSC-associated primary or acquired resistance to cancer treatment. Given the crosstalk between the different embryonic developmental signalling pathways, as well as other pathways, designing clinical trials that target CSCs with rational combinations of agents to inhibit possible compensatory escape mechanisms could be of particular importance. We also share our views on the future directions for targeting CSCs to advance the clinical development of these classes of agents. PMID:25850553

Functional maturation of motor nerve terminals in the avian iris: ultrastructure, transmitter metabolism and synaptic reliability

PubMed Central

Pilar, Guillermo; Tuttle, Jeremy; Vaca, Ken

1981-01-01

1. The transformation of easily fatigued embryonic neuromuscular junctions into highly reliable mature terminals was examined by studying functional and morphological changes during development of the avian iris. The mature ability to follow repetitive electrical nerve stimulation was correlated with the rate of acetylcholine (ACh) synthesis and choline uptake, and with the fine structure of the nerve terminals and the post-synaptic elements. 2. The terminals of the ciliary nerve of the chick initially form functional synaptic contacts with the iris muscle at embryonic St. 34-40. At the onset of this period, no Na+-dependent high affinity choline uptake can be demonstrated, and the low level of ACh synthesis present is sensitive to Na+ removal. At St. 36 [3H]ACh synthesis begins to increase, the increment being Na+-dependent. 3. ACh synthesis in the embryonic iris was insensitive to a conditioning [K+]o depolarization even as late as St. 43. Just before hatching, depolarization elicits some augmentation in synthesis, but by 2 days ex ovo this release-induced response has increased by an order of magnitude. 4. Concurrently with the acquisition of the ability to respond to depolarization with accelerated synthesis, neuromuscular transmission in the iris becomes reliable and secure during stimulation at 20 Hz. Embryonic junctions rapidly block during such stimulation, and the failure is shown to be presynaptic in origin, resulting most probably from failure to sustain adequate levels of transmitter release. 5. Ultrastructural examination of the developing ciliary terminals revealed few synaptic vesicles at early stages, and a dearth of other specializations. The sequence of development from these small structurally undistinguished endings to large en plaque junctions completely filled with vesicles was reconstructed and compared to other neuromuscular junctions. Morphological maturation appears progressive with little evidence of discontinuity signalling functional status, but it is only after the terminals enlarge and become closely packed with vesicles that mature synaptic reliability is found. 6. The temporal correlation between responsiveness of transmitter synthesis to depolarization and reliable neuromuscular transmission suggests that modulation of neurotransmitter metabolism in response to demand signals the achievement of junctional maturity. ImagesABPlate 2Plate 3Plate 4 PMID:6279822

Growth and differentiation of embryonic stem cells that lack an intact c-fos gene.

PubMed Central

Field, S J; Johnson, R S; Mortensen, R M; Papaioannou, V E; Spiegelman, B M; Greenberg, M E

1992-01-01

The c-fos protooncogene encodes a transcription factor that is thought to play a critical role in proliferation and differentiation as well as in the physiological response of mature cells to their environment. To test directly the role of c-fos in growth and differentiation, we generated mouse embryonic stem cell lines in which both copies of the c-fos gene were specifically disrupted by homologous recombination. Remarkably, the disruption of both copies of c-fos in these cells has no detectable effect on embryonic stem cell viability, growth rate, or differentiation potential. Embryonic stem cells lacking c-fos can differentiate into a wide range of cell types in tissue culture and also in chimeric mice. We conclude that despite a large body of literature suggesting an important role for c-fos in cell growth and differentiation, in at least some cell types this gene is not essential for these processes. Images PMID:1329091

Recent advances in the synchronization of estrus and ovulation in dairy cows.

PubMed

Macmillan, Keith L

2010-01-01

Synchronization programs have become standard components in the current breeding management of cows in the dairy herds of most dairy industries. Many are based on protocols that allow timed inseminations (TAI) so as to circumvent the practical difficulties associated with estrus detection. These difficulties are exacerbated in modern herds of high producing cows either because of increasing herd size in which individual animal monitoring is difficult and often subjective, or because small intensively managed herds are milked in robotic systems that minimize animal: staff interactions. Additional reasons arise from high producing cows having less obvious symptoms of estrus, partly because of housing systems combined with intensive feeding and milking, partly because of higher metabolic clearance rates of reproductive hormones like estradiol and partly because of the increasing prevalence of prolonged post-partum anestrus and reproductive tract pathology. The most recently developed programs include protocols for resynchronization following first or subsequent inseminations. These re-synchronization protocols may involve selected forms of hormonal intervention during the diestrous and pro-estrous periods following TAI, or following pregnancy diagnosis by ultrasound from 28 days after TAI. The latter form of re-synchronization has become increasingly important with the recognition that late embryonic/early foetal death has become a major factor compromising the reproductive performance of high producing Holstein cows in many dairy industries. Although cows detected in estrus without any hormonal treatment before insemination have higher conception rates than those inseminated following synchronization and TAI, the low detection rates combined with embryonic death means that intervals from calving to conception (days open) are usually less when synchronization programs have been successfully implemented. One of the significant factors affecting a program's success is the compliance rate that may sometimes be less than 70%. Almost all programs involve strategically timed injections of prostaglandin F2alpha (PGF) and gonadotropin releasing hormone (GnRH). Injections of an estradiol ester and progesterone supplementation per vaginum may be included in some programs. The basic program is the "Ovsynch" regimen. Numerous variations have been tested and developed. Many involve increasingly complex protocols that increase the risk of non-compliance, none has consistently achieved conception rates that exceed 40% and few have reduced the incidence of embryonic death. These synchronization programs are the best that are currently available. They have not been able to overcome the consequences of lowered fertility associated with high levels of milk yield, forms of nutrition and environmental factors like heat stress that have profound effects on the physiology and metabolism of the high producing dairy cow.

Female parthenogenetic apomixis and androsporogenetic parthenogenesis in embryonal cells of Araucaria angustifolia: interpolation of progenesis and asexual heterospory in an artificial sporangium.

PubMed

Durzan, Don J

2012-09-01

Cell fate, development timing and occurrence of reproductive versus apomictic development in gymnosperms are shown to be influenced by culture conditions in vitro. In this study, female parthenogenetic apomixis (fPA), androsporogenetic parthenogenesis (mAP) and progenesis were demonstrated using embryonal initials of Araucaria angustifolia in scaled-up cell suspensions passing through a single-cell bottleneck in darkness and in an artificial sporangium (AS). Expression was based on defined nutrition, hormones and feedforward-adaptive feedback process controls at 23-25 °C and in darkness. In fPA, the nucleus of an embryonal initial undergoes endomitosis and amitosis, forming a diploid egg-equivalent and an apoptotic ventral canal nucleus in a transdifferentiated archegonial tube. Discharge of egg-equivalent cells as parthenospores and their dispersal into the aqueous culture medium were followed by free-nuclear conifer-type proembryogenesis. This replaced the plesiomorphic and central features of proembryogenesis in Araucariaceae. Protoplasmic fusions of embryonal initials were used to reconstruct heterokaryotic expressions of fPA in multiwell plates. In mAP, restitutional meiosis (automixis) was responsible for androsporogenesis and the discharge of monads, dyads, tetrads and polyads. In a display of progenesis, reproductive development was brought to an earlier ontogenetic stage and expressed by embryonal initials. Colchicine increased polyploidy, but androspore formation became aberrant and fragmented. Aberrant automixis led to the formation of chromosomal bouquets, which contributed to genomic silencing in embryonal initials, cytomixis and the formation of pycnotic micronucleated cells. Dispersal of female and male parthenospores displayed heteromorphic asexual heterospory in an aqueous environment.

Impaired embryonic development in glucose-6-phosphate dehydrogenase-deficient Caenorhabditis elegans due to abnormal redox homeostasis induced activation of calcium-independent phospholipase and alteration of glycerophospholipid metabolism.

PubMed

Chen, Tzu-Ling; Yang, Hung-Chi; Hung, Cheng-Yu; Ou, Meng-Hsin; Pan, Yi-Yun; Cheng, Mei-Ling; Stern, Arnold; Lo, Szecheng J; Chiu, Daniel Tsun-Yee

2017-01-12

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a commonly pervasive inherited disease in many parts of the world. The complete lack of G6PD activity in a mouse model causes embryonic lethality. The G6PD-deficient Caenorhabditis elegans model also shows embryonic death as indicated by a severe hatching defect. Although increased oxidative stress has been implicated in both cases as the underlying cause, the exact mechanism has not been clearly delineated. In this study with C. elegans, membrane-associated defects, including enhanced permeability, defective polarity and cytokinesis, were found in G6PD-deficient embryos. The membrane-associated abnormalities were accompanied by impaired eggshell structure as evidenced by a transmission electron microscopic study. Such loss of membrane structural integrity was associated with abnormal lipid composition as lipidomic analysis revealed that lysoglycerophospholipids were significantly increased in G6PD-deficient embryos. Abnormal glycerophospholipid metabolism leading to defective embryonic development could be attributed to the increased activity of calcium-independent phospholipase A 2 (iPLA) in G6PD-deficient embryos. This notion is further supported by the fact that the suppression of multiple iPLAs by genetic manipulation partially rescued the embryonic defects in G6PD-deficient embryos. In addition, G6PD deficiency induced disruption of redox balance as manifested by diminished NADPH and elevated lipid peroxidation in embryos. Taken together, disrupted lipid metabolism due to abnormal redox homeostasis is a major factor contributing to abnormal embryonic development in G6PD-deficient C. elegans.

Triennial Reproduction Symposium: influence of follicular characteristics at ovulation on early embryonic survival.

PubMed

Geary, T W; Smith, M F; MacNeil, M D; Day, M L; Bridges, G A; Perry, G A; Abreu, F M; Atkins, J A; Pohler, K G; Jinks, E M; Madsen, C A

2013-07-01

Reproductive failure in livestock can result from failure to fertilize the oocyte or embryonic loss during gestation. Although fertilization failure occurs, embryonic mortality represents a greater contribution to reproductive failure. Reproductive success varies among species and production goals but is measured as a binomial trait (i.e., pregnancy), derived by the success or failure of multiple biological steps. This review focuses primarily on follicular characteristics affecting oocyte quality, fertilization, and embryonic health that lead to pregnancy establishment in beef cattle. When estrous cycles are manipulated with assisted reproductive technologies and ovulation is induced, duration of proestrus (i.e., interval from induced luteolysis to induced ovulation), ovulatory follicle growth rate, and ovulatory follicle size are factors that affect the maturation of the follicle and oocyte at induced ovulation. The most critical maturational component of the ovulatory follicle is the production of sufficient estradiol to prepare follicular cells for luteinization and progesterone synthesis and prepare the uterus for pregnancy. The exact roles of estradiol in oocyte maturation remain unclear, but cows that have lesser serum concentrations of estradiol have decreased fertilization rates and decreased embryo survival on d 7 after induced ovulation. When length of proestrus is held constant, perhaps the most practical follicular measure of fertility is ovulatory follicle size because it is an easily measured attribute of the follicle that is highly associated with its ability to produce estradiol.

Effects of dieldrin treatment on physiological and biochemical aspects of the toad embryonic development

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

Gauna, L.; Caballero de Castro, A.; Chifflet de Llamas, M.

1991-04-01

Dieldrin is a cylclodiene insecticide highly persistent in nature due to its chemical stability. The exposure of toad embryos to Dieldrin induces hyperactivity in the swimming larvae and inhibition of cholinesterases. However, the inhibition of these enzymes during early development is not life threatening. The present report provides a physiological and biochemical study of the noxious effect of Dieldrin on the toad embryonic development.

Secondary corpora lutea induced by HCG treatment enhanced demi-embryo survival in lactating high-yielding dairy cows.

PubMed

Torres, A; Chagas e Silva, J; Deloche, M C; Humblot, P; Horta, A E M; Lopes-da-Costa, L

2013-08-01

Using a novel in vivo model considering a low developmental competence embryo (demi-embryo) and a subnormal fertility recipient (lactating high-yielding dairy cow), this experiment evaluated the effect of human chorionic gonadotrophin (hCG) treatment at embryo transfer (ET) on embryonic size at implantation, embryonic survival and recipient plasma progesterone (P4 ) and bovine pregnancy-specific protein B (PSPB) concentrations until day 63 of pregnancy. Embryos were bisected and each pair of demi-embryos was bilaterally transferred to recipients (n = 61) on day 7 of the oestrous cycle. At ET recipients were randomly assigned to treatment with 1500 IU hCG or to untreated controls. Higher (p < 0.01) pregnancy rates on days 25, 42 and 63, and embryo survival rate on day 63 were observed in hCG-treated cows with secondary CL than in hCG-treated cows without secondary CL and in untreated cows. Pregnancy rates and embryo survival rate were similar in hCG-treated cows without secondary CL and untreated cows. Embryonic size on day 42 was not affected by treatment with hCG, presence of secondary CL and type of pregnancy (single vs twin). Presence of secondary CL increased (p < 0.05) plasma P4 concentrations of pregnant cows on days 14, 19 and 25 but not thereafter and of non-pregnant cows on days 14-21. Treatment with hCG and presence of secondary CL had no effect on plasma PSPB concentrations, which were higher (p < 0.05) in twin than in single pregnancies. In conclusion, secondary CL induced by hCG treatment at ET significantly increased plasma P4 concentrations, the survival rate of demi-embryos and the pregnancy rate of high-yielding lactating dairy cows. Embryos were rescued beyond maternal recognition of pregnancy, but later embryonic survival, growth until implantation and placental PSPB secretion until day 63 of pregnancy were not affected by treatment or presence of secondary CL. © 2013 Blackwell Verlag GmbH.

The impact of CO2-driven ocean acidification on early development and calcification in the sea urchin Strongylocentrotus intermedius.

PubMed

Zhan, Yaoyao; Hu, Wanbin; Zhang, Weijie; Liu, Minbo; Duan, Lizhu; Huang, Xianya; Chang, Yaqing; Li, Cong

2016-11-15

The impact of CO 2 -driven ocean acidification(OA) on early development and calcification in the sea urchin Strongylocentrotus intermedius cultured in northern Yellow Sea was investigated by comparing fertilization success, early cleavage rate, hatching rate of blastulae, larvae survival rate at 70h post-fertilization, larval morphology and calcification under present natural seawater condition (pH=8.00±0.03) and three laboratory-controlled acidified conditions (OA 1 , △pH=-0.3units; OA 2 , △pH=-0.4units; OA 3 , △pH=-0.5units) projected by IPCC for 2100. Results showed that pH decline had no effect on the overall fertilization, however, with decreased pH, delayed early embryonic cleavage, reduced hatching rate of blastulae and four-armed larvae survival rate at 70h post-fertilization, impaired larval symmetry, shortened larval spicules, and corrosion spicule structure were observed in all OA-treated groups as compared to control, which indicated that CO 2 -driven OA affected early development and calcification in S. intermedius negatively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Morphogenetic Implications of Peristalsis-Driven Fluid Flow in the Embryonic Lung

PubMed Central

Bokka, Kishore K.; Jesudason, Edwin C.; Lozoya, Oswaldo A.; Guilak, Farshid; Warburton, David; Lubkin, Sharon R.

2015-01-01

Epithelial organs are almost universally secretory. The lung secretes mucus of extremely variable consistency. In the early prenatal period, the secretions are of largely unknown composition, consistency, and flow rates. In addition to net outflow from secretion, the embryonic lung exhibits transient reversing flows from peristalsis. Airway peristalsis (AP) begins as soon as the smooth muscle forms, and persists until birth. Since the prenatal lung is liquid-filled, smooth muscle action can transport fluid far from the immediately adjacent tissues. The sensation of internal fluid flows has been shown to have potent morphogenetic effects, as has the transport of morphogens. We hypothesize that these effects play an important role in lung morphogenesis. To test these hypotheses in a quantitative framework, we analyzed the fluid-structure interactions between embryonic tissues and lumen fluid resulting from peristaltic waves that partially occlude the airway. We found that if the airway is closed, fluid transport is minimal; by contrast, if the trachea is open, shear rates can be very high, particularly at the stenosis. We performed a parametric analysis of flow characteristics' dependence on tissue stiffnesses, smooth muscle force, geometry, and fluid viscosity, and found that most of these relationships are governed by simple ratios. We measured the viscosity of prenatal lung fluid with passive bead microrheology. This paper reports the first measurements of the viscosity of embryonic lung lumen fluid. In the range tested, lumen fluid can be considered Newtonian, with a viscosity of 0.016 ± 0.008 Pa-s. We analyzed the interaction between the internal flows and diffusion and conclude that AP has a strong effect on flow sensing away from the tip and on transport of morphogens. These effects may be the intermediate mechanisms for the enhancement of branching seen in occluded embryonic lungs. PMID:26147967

First trimester size charts of embryonic brain structures.

PubMed

Gijtenbeek, M; Bogers, H; Groenenberg, I A L; Exalto, N; Willemsen, S P; Steegers, E A P; Eilers, P H C; Steegers-Theunissen, R P M

2014-02-01

Can reliable size charts of human embryonic brain structures be created from three-dimensional ultrasound (3D-US) visualizations? Reliable size charts of human embryonic brain structures can be created from high-quality images. Previous studies on the visualization of both the cavities and the walls of the brain compartments were performed using 2D-US, 3D-US or invasive intrauterine sonography. However, the walls of the diencephalon, mesencephalon and telencephalon have not been measured non-invasively before. Last-decade improvements in transvaginal ultrasound techniques allow a better visualization and offer the tools to measure these human embryonic brain structures with precision. This study is embedded in a prospective periconceptional cohort study. A total of 141 pregnancies were included before the sixth week of gestation and were monitored until delivery to assess complications and adverse outcomes. For the analysis of embryonic growth, 596 3D-US scans encompassing the entire embryo were obtained from 106 singleton non-malformed live birth pregnancies between 7(+0) and 12(+6) weeks' gestational age (GA). Using 4D View (3D software) the measured embryonic brain structures comprised thickness of the diencephalon, mesencephalon and telencephalon, and the total diameter of the diencephalon and mesencephalon. Of 596 3D scans, 161 (27%) high-quality scans of 79 pregnancies were eligible for analysis. The reliability of all embryonic brain structure measurements, based on the intra-class correlation coefficients (ICCs) (all above 0.98), was excellent. Bland-Altman plots showed moderate agreement for measurements of the telencephalon, but for all other measurements the agreement was good. Size charts were constructed according to crown-rump length (CRL). The percentage of high-quality scans suitable for analysis of these brain structures was low (27%).  The size charts of human embryonic brain structures can be used to study normal and abnormal development of brain development in future. Also, the effects of periconceptional maternal exposures, such as folic acid supplement use and smoking, on human embryonic brain development can be a topic of future research. This study was supported by the Department of Obstetrics and Gynaecology of the Erasmus University Medical Center. M.G. was supported by an additional grant from the Sophia Foundation for Medical Research (SSWO grant number 644). No competing interests are declared.

Effect of the anti-androgenic endocrine disruptor vinclozolin on embryonic testis cord formation and postnatal testis development and function.

PubMed

Uzumcu, Mehmet; Suzuki, Hiroetsu; Skinner, Michael K

2004-01-01

Vinclozolin is a systemic dicarboximide fungicide that is used on fruits, vegetables, ornamental plants, and turf grass. Vinclozolin and its metabolites are known to be endocrine disruptors and act as androgen receptor antagonists. The hypothesis tested in the current study is that transient embryonic exposure to an anti-androgenic endocrine disruptor at the time of testis determination alters testis development and subsequently influences adult spermatogenic capacity and male reproduction. The effects of vinclozolin on embryonic testicular cord formation in vitro were examined, as well as the effects of transient in utero vinclozolin exposure on postnatal testis development and function. Embryonic day 13 (E13, sperm-positive vaginal smear day = E0) gonads were cultured in the absence or presence of vinclozolin (50-500microM). Vinclozolin treated gonads had significantly fewer cords (P < 0.05) and the histology of the cords that formed were abnormal as compared to vehicle-treated organs. Pregnant rats were exposed to vinclozolin (100 mg/kg/day) between embryonic days 8 and 14 (E8-E14) of development. Testis morphology and function were analyzed from postnatal day (P) 0, pubertal P20, and adult P60. No significant effect of vinclozolin on testis histology or germ cell viability was observed in P0 testis. The pubertal P20 testis from vinclozolin exposed animals had significantly higher numbers of apoptotic germ cells (P < 0.01), but testis weight was not affected. The adult P60 sperm motility was significantly lower in vinclozolin exposed males (P < 0.01). In addition, apoptotic germ cell number in testis of vinclozolin exposed animals was higher in adult P60 animals. Observations demonstrate that vinclozolin can effect embryonic testicular cord formation in vitro and that transient in utero exposure to vinclozolin increases apoptotic germ cell numbers in the testis of pubertal and adult animals. This correlated to reduced sperm motility in the adult. In conclusion, transient exposure to vinclozolin during the time of testis differentiation (i.e. cord formation) alters testis development and function. Observations indicate that transient exposure to an anti-androgenic endocrine disruptor during embryonic development causes delayed effects later in adult life on spermatogenic capacity.

The Effects of Simulated Micro-gravity on Cultured Chicken Embryonic Chondrocytes

NASA Astrophysics Data System (ADS)

Li, X.; Zhang, X.; Yang, S.; Li, S.; Peidong, J.; Lin, Z.

T he effects of simulated microgravity on the microtubular system, extracellular matrix, alkaline phosphatase activity, intracellular free calcium concentration, mitochondrial ATP synthase activity and oligomycin inhibition rate of cultured chicken embryonic chondrocytes were studied with a clinostat. The microtubular content decreased. The extracellualr matrix decreased significantly after rotating, and the fibers in the extracellular matrix were more tiny and disorderly. There was a time course decrease in alkaline phosphatase activity of chondrocytes, a marker of matrix mineralization. Meanwhile a significant drop in the intracellular calcium concentration happened at the beginning of rotation. No significant changes happened in the mitochondrial ATP synthase activity and oligomycin inhibition rate. The possible mechanisms about them were discussed.

Reactivation of the Nkx2.5 cardiac enhancer after myocardial infarction does not presage myogenesis.

PubMed

Deutsch, Marcus-André; Doppler, Stefanie A; Li, Xinghai; Lahm, Harald; Santamaria, Gianluca; Cuda, Giovanni; Eichhorn, Stefan; Ratschiller, Thomas; Dzilic, Elda; Dreßen, Martina; Eckart, Annekathrin; Stark, Konstantin; Massberg, Steffen; Bartels, Anna; Rischpler, Christoph; Gilsbach, Ralf; Hein, Lutz; Fleischmann, Bernd K; Wu, Sean M; Lange, Rüdiger; Krane, Markus

2018-03-20

The contribution of resident stem or progenitor cells to cardiomyocyte renewal after injury in adult mammalian hearts remains a matter of considerable debate. We evaluated a cell population in the adult mouse heart induced by myocardial infarction (MI) and characterized by an activated Nkx2.5 enhancer element that is specific for multipotent cardiac progenitor cells during embryonic development. We hypothesized that these MI induced cells (MICs) harbor cardiomyogenic properties similar to their embryonic counterparts. MICs reside in the heart and mainly localize to the infarction area and border zone. Interestingly, gene expression profiling of purified MICs one week after infarction revealed increased expression of stem cell markers and embryonic cardiac transcription factors in these cells as compared to the non-mycoyte cell fraction of adult hearts. A subsequent global transcriptome comparison with embryonic cardiac progenitor cells and fibroblasts and in vitro culture of MICs unveiled that (myo-) fibroblastic features predominated and that cardiac transcription factors were only expressed at background levels. Adult injury induced reactivation of a cardiac-specific Nkx2.5 enhancer element known to specifically mark myocardial progenitor cells during embryonic development does not reflect hypothesized embryonic cardiomyogenic properties. Our data suggest a decreasing plasticity of cardiac progenitor (-like) cell populations with increasing age. A re-expression of embryonic, stem or progenitor cell features in the adult heart must be interpreted very carefully with respect to the definition of cardiac resident progenitor cells. Albeit, the abundance of scar formation after cardiac injury suggests a potential to target predestinated activated profibrotic cells to push them towards cardiomyogenic differentiation to improve regeneration.

Metabolic Profiling and Flux Analysis of MEL-2 Human Embryonic Stem Cells during Exponential Growth at Physiological and Atmospheric Oxygen Concentrations

PubMed Central

Titmarsh, Drew; Krömer, Jens O.; Kao, Li-Pin; Nielsen, Lars; Wolvetang, Ernst; Cooper-White, Justin

2014-01-01

As human embryonic stem cells (hESCs) steadily progress towards regenerative medicine applications there is an increasing emphasis on the development of bioreactor platforms that enable expansion of these cells to clinically relevant numbers. Surprisingly little is known about the metabolic requirements of hESCs, precluding the rational design and optimisation of such platforms. In this study, we undertook an in-depth characterisation of MEL-2 hESC metabolic behaviour during the exponential growth phase, combining metabolic profiling and flux analysis tools at physiological (hypoxic) and atmospheric (normoxic) oxygen concentrations. To overcome variability in growth profiles and the problem of closing mass balances in a complex environment, we developed protocols to accurately measure uptake and production rates of metabolites, cell density, growth rate and biomass composition, and designed a metabolic flux analysis model for estimating internal rates. hESCs are commonly considered to be highly glycolytic with inactive or immature mitochondria, however, whilst the results of this study confirmed that glycolysis is indeed highly active, we show that at least in MEL-2 hESC, it is supported by the use of oxidative phosphorylation within the mitochondria utilising carbon sources, such as glutamine to maximise ATP production. Under both conditions, glycolysis was disconnected from the mitochondria with all of the glucose being converted to lactate. No difference in the growth rates of cells cultured under physiological or atmospheric oxygen concentrations was observed nor did this cause differences in fluxes through the majority of the internal metabolic pathways associated with biogenesis. These results suggest that hESCs display the conventional Warburg effect, with high aerobic activity despite high lactate production, challenging the idea of an anaerobic metabolism with low mitochondrial activity. The results of this study provide new insight that can be used in rational bioreactor design and in the development of novel culture media for hESC maintenance and expansion. PMID:25412279

Identification of microRNAs controlling hepatic mRNA levels for metabolic genes during the metabolic transition from embryonic to posthatch development in the chicken.

PubMed

Hicks, Julie A; Porter, Tom E; Liu, Hsiao-Ching

2017-09-05

The transition from embryonic to posthatch development in the chicken represents a massive metabolic switch from primarily lipolytic to primarily lipogenic metabolism. This metabolic switch is essential for the chick to successfully transition from the metabolism of stored egg yolk to the utilization of carbohydrate-based feed. However, regulation of this metabolic switch is not well understood. We hypothesized that microRNAs (miRNAs) play an important role in the metabolic switch that is essential to efficient growth of chickens. We used high-throughput RNA sequencing to characterize expression profiles of mRNA and miRNA in liver during late embryonic and early posthatch development of the chicken. This extensive data set was used to define the contributions of microRNAs to the metabolic switch during development that is critical to growth and nutrient utilization in chickens. We found that expression of over 800 mRNAs and 30 miRNAs was altered in the embryonic liver between embryonic day 18 and posthatch day 3, and many of these differentially expressed mRNAs and miRNAs are associated with metabolic processes. We confirmed the regulation of some of these mRNAs by miRNAs expressed in a reciprocal pattern using luciferase reporter assays. Finally, through the use of yeast one-hybrid screens, we identified several proteins that likely regulate expression of one of these important miRNAs. Integration of the upstream regulatory mechanisms governing miRNA expression along with monitoring the downstream effects of this expression will ultimately allow for the construction of complete miRNA regulatory networks associated with the hepatic metabolic switch in chickens. Our findings support a key role for miRNAs in controlling the metabolic switch that occurs between embryonic and posthatch development in the chicken.

Embryonic development during chronic acceleration

NASA Technical Reports Server (NTRS)

Smith, A. H.; Abbott, U. K.

1982-01-01

Experiments carried out on chicken eggs indicate that the embryo is affected during very early development, especially over the first four days, and during hatching. In the first four days, the brain develops as well as the anlage for all other organs. In addition, the heart commences to function and the extraembryonic membranes that compartmentalize the egg contents form. The latter require an appreciable extension and folding of tissue which may be disrupted by the mechanical load. Observations of embryonic abnormalities that occur during chronic acceleration suggest an inhibition of development of the axial skeleton, which is rarely seen otherwise, a general retardation of embryonic growth, and circulatory problems. The final stages of development (after 18 days) involve the uptake of fluids, the transition to aerial respiration, and the reorientation of the embryo into a normal hatching position. At 4 G mortality is very high during this period, with a majority of embryos failing to reorient into the normal hatching position.

Gravity and embryonic development

NASA Technical Reports Server (NTRS)

Young, R. S.

1976-01-01

The relationship between the developing embryo (both plant and animal) and a gravitational field has long been contemplated. The difficulty in designing critical experiments on the surface of the earth because of its background of 1 g, has been an obstacle to a resolution of the problem. Biological responses to gravity (particularly in plants) are obvious in many cases; however, the influence of gravity as an environmental input to the developing embryo is not as obvious and has proven to be extremely difficult to define. In spite of this, over the years numerous attempts have been made using a variety of embryonic materials to come to grips with the role of gravity in development. Three research tools are available: the centrifuge, the clinostat, and the orbiting spacecraft. Experimental results are now available from all three sources. Some tenuous conclusions are drawn, and an attempt at a unifying theory of gravitational influence on embryonic development is made.

Verification of a model for predicting the effect of inconstant temperature on embryonic development of lake whitefish (Coregonus clupeaformis)

USGS Publications Warehouse

Berlin, William H.; Brooke, L.T.; Stone, Linda J.

1977-01-01

The model was used to predict the effects of small temperature increases (caused by a hypothetical waste-heat discharge) on the rate of development and time of hatching of lake whitefish eggs. According to this simulation, continuous addition of waste heat sufficient to raise the temperature 1, 2, or 3 C above ambient on the spawning grounds during December-April would advance the time of hatching 8, 16, or 21 days, respectively. Possible effects of this advancement on the reproductive success of whitefish are discussed.

Sperm and Spermatids Contain Different Proteins and Bind Distinct Egg Factors

PubMed Central

Teperek, Marta; Miyamoto, Kei; Simeone, Angela; Feret, Renata; Deery, Michael J.; Gurdon, John B.; Jullien, Jerome

2014-01-01

Spermatozoa are more efficient at supporting normal embryonic development than spermatids, their immature, immediate precursors. This suggests that the sperm acquires the ability to support embryonic development during spermiogenesis (spermatid to sperm maturation). Here, using Xenopus laevis as a model organism, we performed 2-D Fluorescence Difference Gel Electrophoresis (2D-DIGE) and mass spectrometry analysis of differentially expressed proteins between sperm and spermatids in order to identify factors that could be responsible for the efficiency of the sperm to support embryonic development. Furthermore, benefiting from the availability of egg extracts in Xenopus, we also tested whether the chromatin of sperm could attract different egg factors compared to the chromatin of spermatids. Our analysis identified: (1) several proteins which were present exclusively in sperm; but not in spermatid nuclei and (2) numerous egg proteins binding to the sperm (but not to the spermatid chromatin) after incubation in egg extracts. Amongst these factors we identified many chromatin-associated proteins and transcriptional repressors. Presence of transcriptional repressors binding specifically to sperm chromatin could suggest its preparation for the early embryonic cell cycles, during which no transcription is observed and suggests that sperm chromatin has a unique protein composition, which facilitates the recruitment of egg chromatin remodelling factors. It is therefore likely that the acquisition of these sperm-specific factors during spermiogenesis makes the sperm chromatin suitable to interact with the maternal factors and, as a consequence, to support efficient embryonic development. PMID:25244019

Early events in xenograft development from the human embryonic stem cell line HS181--resemblance with an initial multiple epiblast formation.

PubMed

Gertow, Karin; Cedervall, Jessica; Jamil, Seema; Ali, Rouknuddin; Imreh, Marta P; Gulyas, Miklos; Sandstedt, Bengt; Ahrlund-Richter, Lars

2011-01-01

Xenografting is widely used for assessing in vivo pluripotency of human stem cell populations. Here, we report on early to late events in the development of mature experimental teratoma from a well-characterized human embryonic stem cell (HESC) line, HS181. The results show an embryonic process, increasingly chaotic. Active proliferation of the stem cell derived cellular progeny was detected already at day 5, and characterized by the appearance of multiple sites of engraftment, with structures of single or pseudostratified columnar epithelium surrounding small cavities. The striking histological resemblance to developing embryonic ectoderm, and the formation of epiblast-like structures was supported by the expression of the markers OCT4, NANOG, SSEA-4 and KLF4, but a lack of REX1. The early neural marker NESTIN was uniformly expressed, while markers linked to gastrulation, such as BMP-4, NODAL or BRACHYURY were not detected. Thus, observations on day 5 indicated differentiation comparable to the most early transient cell populations in human post implantation development. Confirming and expanding on previous findings from HS181 xenografts, these early events were followed by an increasingly chaotic development, incorporated in the formation of a benign teratoma with complex embryonic components. In the mature HS181 teratomas not all types of organs/tissues were detected, indicating a restricted differentiation, and a lack of adequate spatial developmental cues during the further teratoma formation. Uniquely, a kinetic alignment of rare complex structures was made to human embryos at diagnosed gestation stages, showing minor kinetic deviations between HS181 teratoma and the human counterpart.

The embryonic mir-35 family of microRNAs promotes multiple aspects of fecundity in Caenorhabditis elegans.

PubMed

McJunkin, Katherine; Ambros, Victor

2014-07-21

MicroRNAs guide many aspects of development in all metazoan species. Frequently, microRNAs are expressed during a specific developmental stage to perform a temporally defined function. The C. elegans mir-35-42 microRNAs are expressed abundantly in oocytes and early embryos and are essential for embryonic development. Here, we show that these embryonic microRNAs surprisingly also function to control the number of progeny produced by adult hermaphrodites. Using a temperature-sensitive mir-35-42 family mutant (a deletion of the mir-35-41 cluster), we demonstrate three distinct defects in hermaphrodite fecundity. At permissive temperatures, a mild sperm defect partially reduces hermaphrodite fecundity. At restrictive temperatures, somatic gonad dysfunction combined with a severe sperm defect sharply reduces fecundity. Multiple lines of evidence, including a late embryonic temperature-sensitive period, support a role for mir-35-41 early during development to promote subsequent sperm production in later larval stages. We further show that the predicted mir-35 family target sup-26 (suppressor-26) acts downstream of mir-35-41 in this process, suggesting that sup-26 de-repression in mir-35-41 deletion mutants may contribute to temperature-sensitive loss of fecundity. In addition, these microRNAs play a role in male fertility, promoting proper morphogenesis of male-specific mating structures. Overall, our results demonstrate that robust activity of the mir-35-42 family microRNAs not only is essential for embryonic development across a range of temperatures but also enables the worm to subsequently develop full reproductive capacity. Copyright © 2014 McJunkin and Ambros.

Neural Organization of the Optic Lobe Changes Steadily from Late Embryonic Stage to Adulthood in Cuttlefish Sepia pharaonis

PubMed Central

Liu, Yung-Chieh; Liu, Tsung-Han; Su, Chia-Hao; Chiao, Chuan-Chin

2017-01-01

The optic lobe is the largest structure in the cuttlefish brain. While the general morphology of the optic lobe in adult cuttlefish has been well described, the 3D structure and ontogenetic development of its neural organization have not been characterized. To correlate observed behavioral changes within the brain structure along the development of this animal, optic lobes from the late embryonic stage to adulthood were examined systematically in the present study. The MRI scan revealed that the so called “cell islands” in the medulla of the cephalopod's optic lobe (Young, 1962, 1974) are in fact a contiguous tree-like structure. Quantification of the neural organizational development of optic lobes showed that structural features of the cortex and radial column zone were established earlier than those of the tangential zone during embryonic and post-hatching stages. Within the cell islands, the density of nuclei was decreased while the size of nuclei was increased during the development. Furthermore, the visual processing area in the optic lobe showed a significant variation in lateralization during embryonic and juvenile stages. Our observation of a continuous increase in neural fibers and nucleus size in the tangential zone of the optic lobe from late embryonic stage to adulthood indicates that the neural organization of the optic lobe is modified along the development of cuttlefish. These findings thus support that the ontogenetic change of the optic lobe is responsible for their continuously increased complexity in body patterning and visuomotor behaviors. PMID:28798695

The miR-290-295 cluster as multi-faceted players in mouse embryonic stem cells.

PubMed

Yuan, Kai; Ai, Wen-Bing; Wan, Lin-Yan; Tan, Xiao; Wu, Jiang-Feng

2017-01-01

Increasing evidence indicates that embryonic stem cell specific microRNAs (miRNAs) play an essential role in the early development of embryo. Among them, the miR-290-295 cluster is the most highly expressed in the mouse embryonic stem cells and involved in various biological processes. In this paper, we reviewed the research progress of the function of the miR-290-295 cluster in embryonic stem cells. The miR-290-295 cluster is involved in regulating embryonic stem cell pluripotency maintenance, self-renewal, and reprogramming somatic cells to an embryonic stem cell-like state. Moreover, the miR-290-295 cluster has a latent pro-survival function in embryonic stem cells and involved in tumourigenesis and senescence with a great significance. Elucidating the interaction between the miR-290-295 cluster and other modes of gene regulation will provide us new ideas on the biology of pluripotent stem cells. In the near future, the broad prospects of the miRNA cluster will be shown in the stem cell field, such as altering cell identities with high efficiency through the transient introduction of tissue-specific miRNA cluster.

Isolation and characterization of the trophectoderm from the Arabian camel (Camelus dromedarius).

PubMed

Saadeldin, Islam M; Swelum, Ayman Abdel-Aziz; Elsafadi, Mona; Moumen, Abdullah F; Alzahrani, Faisal A; Mahmood, Amer; Alfayez, Musaad; Alowaimer, Abdullah N

2017-09-01

We isolated and characterized trophoblast from in vivo-derived camel embryos and compared with embryonic stem-like cells. Camel embryos were flushed on day 8 post-insemination and used to derive trophectoderm and embryonic stem-like cells under feeder-free culture conditions using a basement membrane matrix. Embryos were evaluated for the expression of POU5F1, MYC, KLF4, SOX2, CDX2, and KRT8 mRNA transcripts by relative quantitative polymerase chain reaction. Camel embryos grew and expanded to ∼4.5 mm and maintained their vesicular shape in vitro for 21 days post-insemination. Trophoblast and embryonic stem-like cell lines grew under feeder-free culture conditions and showed distinct morphological criteria and normal chromosomal counts. Embryonic stem-like cells showed positive staining in the alkaline phosphatase reaction. Trophoblast cells showed a significant increase in CDX2, KRT8, KLF4, and SOX2 expression compared with embryonic stem-like cells and whole embryos. Embryonic stem-like cells showed a significant decrease in CDX2 expression and increase in SOX2 and KRT8 expression compared to embryonic expression. POU5F1 and MYC expression showed no difference between embryos and both cell lines. We characterized embryo survival in vitro, particularly the derivation of trophectoderm and embryonic stem-like cells, providing a foundation for further analysis of early embryonic development and placentation in camels. Copyright © 2017 Elsevier Ltd. All rights reserved.

High Fat Diet Induced Developmental Defects in the Mouse: Oocyte Meiotic Aneuploidy and Fetal Growth Retardation/Brain Defects

PubMed Central

Purcell, Scott H.; Chi, Maggie; Jimenez, Patricia T.; Grindler, Natalia; Schedl, Tim; Moley, Kelle H.

2012-01-01

Background Maternal obesity is associated with poor outcomes across the reproductive spectrum including infertility, increased time to pregnancy, early pregnancy loss, fetal loss, congenital abnormalities and neonatal conditions. Furthermore, the proportion of reproductive-aged woman that are obese in the population is increasing sharply. From current studies it is not clear if the origin of the reproductive complications is attributable to problems that arise in the oocyte or the uterine environment. Methodology/Principal Findings We examined the developmental basis of the reproductive phenotypes in obese animals by employing a high fat diet mouse model of obesity. We analyzed very early embryonic and fetal phenotypes, which can be parsed into three abnormal developmental processes that occur in obese mothers. The first is oocyte meiotic aneuploidy that then leads to early embryonic loss. The second is an abnormal process distinct from meiotic aneuploidy that also leads to early embryonic loss. The third is fetal growth retardation and brain developmental abnormalities, which based on embryo transfer experiments are not due to the obese uterine environment but instead must be from a defect that arises prior to the blastocyst stage. Conclusions/Significance Our results suggest that reproductive complications in obese females are, at least in part, from oocyte maternal effects. This conclusion is consistent with IVF studies where the increased pregnancy failure rate in obese women returns to the normal rate if donor oocytes are used instead of autologous oocytes. We postulate that preconceptional weight gain adversely affects pregnancy outcomes and fetal development. In light of our findings, preconceptional counseling may be indicated as the preferable, earlier target for intervention in obese women desiring pregnancy and healthy outcomes. PMID:23152876

Impact of di-ethylhexylphthalate exposure on metabolic programming in P19 ECC-derived cardiomyocytes.

PubMed

Schaedlich, Kristina; Schmidt, Juliane-Susanne; Kwong, Wing Yee; Sinclair, Kevin D; Kurz, Randy; Jahnke, Heinz-Georg; Fischer, Bernd

2015-07-01

Di(2-ethylhexyl)phthalate (DEHP) is the most common plasticizer in plastic devices of everyday use. It is a ubiquitous environmental contaminant and primarily known to impair male gonadal development and fertility. Studies concerning the long-term effects of prenatal DEHP exposure on certain diseases [The Developmental Origins of Health and Disease paradigm (DOHaD) hypothesis] are scarce although it is proven that DEHP crosses the placenta. Rising environmental pollution during the last centuries coincides with an increasing prevalence of cardiovascular and metabolic diseases. We have investigated the effects of an early embryonic DEHP exposure at different developmental stages on cardiomyogenesis. We used an in-vitro model, the murine P19 embryonic carcinoma cell line (P19 ECC), mimicking early embryonic stages up to differentiated beating cardiomyocytes. P19 ECC were exposed to DEHP (5, 50, 100 µg ml(-1)) at the undifferentiated stage for 5 days and subsequently differentiated to beating cardiomyocytes. We analyzed the expression of metabolic (Pparg1, Fabp4 and Glut4), cardiac (Myh6, Gja1) and methylation (Dnmt1, Dnmt3a) marker genes by quantitative real-time PCR (qRT-PCR), beating rate and the differentiation velocity of the cells. The methylation status of Pparg1, Ppara and Glut4 was investigated by pyrosequencing. DEHP significantly altered the expression of all investigated genes. The beating rate and differentiation velocity were accelerated. Exposure to DEHP led to small but statistically significant increases in methylation of specific CpGs within Ppara and Pparg1, which otherwise were generally hypomethylated, but methylation of Glut4 was unaltered. Early DEHP exposure of P19 ECC alters the expression of genes associated with cellular metabolism and the functional features of cardiomyocytes. Copyright © 2014 John Wiley & Sons, Ltd.

ACTIONS OF THE ENDOCRINE DISRUPTOR METHOXYCHLOR AND ITS ESTROGENIC METABOLITE ON IN VITRO EMBRYONIC RAT SEMINIFEROUS CORD FORMATION AND PERINATAL TESTIS GROWTH. (R827405)

EPA Science Inventory

Abstract

The current study examines the actions of methoxychlor and its estrogenic metabolite, 2, 2-bis-(p-hydroxyphenyl)-1, 1, 1-trichloroethane (HPTE), on seminiferous cord formation and growth of the developing rat testis. The developing testis in the embryonic and ...

Generation of the Dimensional Embryology Application (App) for Visualization of Early Chick and Frog Embryonic Development

ERIC Educational Resources Information Center

Webb, Rebecca L.; Bilitski, James; Zerbee, Alyssa; Symans, Alexandra; Chop, Alexandra; Seitz, Brianne; Tran, Cindy

2015-01-01

The study of embryonic development of multiple organisms, including model organisms such as frogs and chicks, is included in many undergraduate biology programs, as well as in a variety of graduate programs. As our knowledge of biological systems increases and the amount of material to be taught expands, the time spent instructing students about…

In Situ Estuarine and Marine Toxicity Testing: A Review, Including Recommendations for Future Use in Ecological Risk Assessment

DTIC Science & Technology

2009-09-01

testing may be a preferable or complementary strategy in certain situations utilizing a weight of evidence approach (Baird et al. 2007). One of the most...embryonic development, or post-exposure feeding rate are discussed. It is acknowledged that a plethora of additional endpoints have utility for use in situ...example, may have proven utility , it is generally preferable to evaluate toxicity using ecologically relevant species and life stages (i.e., those

Developmental origin of limb size variation in lizards.

PubMed

Andrews, Robin M; Skewes, Sable A

2017-05-01

In many respects, reptile hatchlings are fully functional, albeit miniature, adults. This means that the adult morphology must emerge during embryonic development. This insight emphasizes the connection between the mechanisms that generate phenotypic variation during embryonic development and the action of selection on post-hatching individuals. To determine when species-specific differences in limb and tail lengths emerge during embryonic development, we compared allometric patterns of early limb growth of four distantly related species of lizards. The major questions addressed were whether early embryonic limb and tail growth is characterized by the gradual (continuous allometry) or by the abrupt emergence (transpositional allometry) of size differences among species. Our observations supported transpositional allometry of both limbs and tails. Species-specific differences in limb and tail length were exhibited when limb and tail buds first protruded from the body wall. Genes known to be associated with early limb development of tetrapods are obvious targets for studies on the genetic mechanisms that determine interspecific differences in relative limb length. Broadly comparative studies of gene regulation would facilitate understanding of the mechanisms underlying adaptive variation in limb size, including limb reduction and loss, of squamate reptiles. © 2017 Wiley Periodicals, Inc.

Evidence of increased endometrial vascular permeability at the time of implantation in the short-nosed fruit bat, Cyanopterus sphinx.

PubMed

Pakrasi, Pranab Lal; Tiwari, Anjana

2007-09-01

Early embryonic development and implantation were studied in tropical short-nosed fruit bat Cyanopterus sphinx. We report preimplantation development and embryo implantation. Different stages of cleavage were observed in embryo by direct microscopic examination of fresh embryos after retrieving them either from the oviduct or the uterus at different days, up to the day of implantation. Generally, the embryos enter the uterus at the 8-cell stage. Embryonic development continued without any delay and blastocyst were formed showing attachment to the uterine epithelium at the mesometrial side of the uterus. A distinct blue band was formed in the uterus. The site of blastocyst attachment was visualized as a blue band following intravenous injection of pontamine blue. Implantation occurred 9+/-0.7 days after mating. This study reports that bat embryonic development can be studied like other laboratory animals and that this bat shows blue dye reaction, indicating the site and exact time of implantation. This blue dye reaction can be used to accurately find post-implantational delay. We prove conclusively that this species of tropical bat does not have any type of embryonic diapause.

TORC2 signaling antagonizes SKN-1 to induce C. elegans mesendodermal embryonic development

PubMed Central

Ruf, Vanessa; Holzem, Christina; Peyman, Tobias; Walz, Gerd; Blackwell, T. Keith; Neumann-Haefelin, Elke

2013-01-01

The evolutionarily conserved target of rapamycin (TOR) kinase controls fundamental metabolic processes to support cell and tissue growth. TOR functions within the context of two distinct complexes, TORC1 and TORC2. TORC2, with its specific component Rictor, has been recently implicated in aging and regulation of growth and metabolism. Here, we identify rict-1/Rictor as a regulator of embryonic development in C. elegans. The transcription factor skn-1 establishes development of the mesendoderm in embryos, and is required for cellular homeostasis and longevity in adults. Loss of maternal skn-1 function leads to misspecification of the mesendodermal precursor and failure to form intestine and pharynx. We found that genetic inactivation of rict-1 suppressed skn-1-associated lethality by restoring mesendodermal specification in skn-1 deficient embryos. Inactivation of other TORC2 but not TORC1 components also partially rescued skn-1 embryonic lethality. The SGK-1 kinase mediated these functions downstream of rict-1/TORC2, as a sgk-1 gain-of-function mutant suppressed the rict-1 mutant phenotype. These data indicate that TORC2 and SGK-1 antagonize SKN-1 during embryonic development. PMID:23973804

Effects of storage conditions on hatchability, embryonic survival and cytoarchitectural properties in broiler from young and old flocks.

PubMed

Pokhrel, N; Cohen, E Ben-Tal; Genin, O; Ruzal, M; Sela-Donenfeld, D; Cinnamon, Y

2018-04-01

Storing eggs at low temperature prior to incubation is common practice in the broiler hatchery industry; however, prolonged storage (beyond 7 d) is known to increase early embryonic mortality and reduce chick quality and performance. To better understand the basis of this mortality, we previously published milestone criteria to evaluate morphological and cellular properties of the freshly laid embryo. Using these criteria, in the present study we checked the effects of storage at 18°C and 12°C for up to 28 d on hatchability and chick quality. Furthermore, using a 3D high-resolution episcopic microscopy (HREM) imaging system combined with standard and confocal microscopy and cell viability markers, we analyzed the effects of the different storage conditions on embryonic developmental stage, cytoarchitectural properties, mitotic index and cell survival. A total of 1,483 eggs from a young flock were divided in 2 groups, 18°C and 12°C, and stored for 7, 14, 21, and 28 d. Following storage, randomly selected 1,222 eggs were incubated, and the hatched chicks were evaluated for chick quality parameters. Nonhatched eggs were also analyzed to determine the stage of embryonic mortality. The remaining 261 eggs were isolated and analyzed for developmental stage, cytoarchitecture, mitotic index, and cell death following storage. Hatchability rates beyond 7 d of storage at 12°C were significantly improved compared to 18°C, and chick quality remained high. Similar results were obtained for an old flock's eggs (n = 1,350). Analyzing the embryos, at each time point, we found that at 12°C, the developmental progression during storage slows significantly, mitotic index-which at this temperature may indicate mitotic arrest-increases and the rate of early apoptosis is half than at 18°C. Moreover, the HREM system and histological sections showed that embryos stored at 18°C for prolonged times undergo dramatic cytoarchitectural changes that may be maladaptive to resuming normal development after diapause. We thus demonstrate the usefulness of the milestone criteria for predicting and studying the storage conditions that will allow for better performance in hatchery practice.

NG2 glia are required for vessel network formation during embryonic development

PubMed Central

Minocha, Shilpi; Valloton, Delphine; Brunet, Isabelle; Eichmann, Anne

2015-01-01

The NG2+ glia, also known as polydendrocytes or oligodendrocyte precursor cells, represent a new entity among glial cell populations in the central nervous system. However, the complete repertoire of their roles is not yet identified. The embryonic NG2+ glia originate from the Nkx2.1+ progenitors of the ventral telencephalon. Our analysis unravels that, beginning from E12.5 until E16.5, the NG2+ glia populate the entire dorsal telencephalon. Interestingly, their appearance temporally coincides with the establishment of blood vessel network in the embryonic brain. NG2+ glia are closely apposed to developing cerebral vessels by being either positioned at the sprouting tip cells or tethered along the vessel walls. Absence of NG2+ glia drastically affects the vascular development leading to severe reduction of ramifications and connections by E18.5. By revealing a novel and fundamental role for NG2+ glia, our study brings new perspectives to mechanisms underlying proper vessels network formation in embryonic brains. DOI: http://dx.doi.org/10.7554/eLife.09102.001 PMID:26651999

Oocyte exposure to ZnO nanoparticles inhibits early embryonic development through the γ-H2AX and NF-κB signaling pathways.

PubMed

Liu, Jing; Zhao, Yong; Ge, Wei; Zhang, Pengfei; Liu, Xinqi; Zhang, Weidong; Hao, Yanan; Yu, Shuai; Li, Lan; Chu, Meiqiang; Min, Lingjiang; Zhang, Hongfu; Shen, Wei

2017-06-27

The impacts of zinc oxide nanoparticles on embryonic development following oocyte stage exposure are unknown and the underlying mechanisms are sparsely understood. In the current investigation, intact nanoparticles were detected in ovarian tissue in vivo and cultured cells in vitro under zinc oxide nanoparticles treatment. Zinc oxide nanoparticles exposure during the oocyte stage inhibited embryonic development. Notably, in vitro culture data closely matched in vivo embryonic data, in that the impairments caused by Zinc oxide nanoparticles treatment passed through cell generations; and both gamma-H2AX and NF-kappaB pathways were involved in zinc oxide nanoparticles caused embryo-toxicity. Copper oxide and silicon dioxide nanoparticles have been used to confirm that particles are important for the toxicity of zinc oxide nanoparticles. The toxic effects of zinc oxide nanoparticles emanate from both intact nanoparticles and Zn2+. Our investigation along with others suggests that zinc oxide nanoparticles are toxic to the female reproductive system [ovaries (oocytes)] and subsequently embryo-toxic and that precaution should be taken regarding human exposure to their everyday use.

In vitro developmental model of the gastrointestinal tract from mouse embryonic stem cells.

PubMed

Torihashi, Shigeko; Kuwahara, Masaki; Kurahashi, Masaaki

2007-10-01

Mouse embryonic stem (ES) cells are pluripotent and retain their potential to form cells, tissues and organs originated from three embryonic germ layers. Recently, we developed in vitro organ--gut-like structures--from mouse ES cells. They had basically similar morphological features to a mouse gastrointestinal tract in vivo composed of three distinct layers (i.e., epithelium, connective tissue and musculature). Gut-like structures showed spontaneous contractions derived from pacemaker cells (interstitial cells of Cajal) in the musculature. We also examined their formation process and expression pattern of transcription factors crucial for gut organogenesis such as Id2, Sox17, HNF3beta/Foxa2 and GATA4. We found that they mimic the development of embryonic gut in vivo and showed a similar expression pattern of common transcription factors. They also maintain their developmental potential after transplantation to a renal capsule. Therefore, gut-like structures are suitable for in vitro models of gastrointestinal tracts and their development. In addition, we pointed out several unique features different from gut in vivo that provide useful and advantageous tools to investigate the developmental mechanism of the gastrointestinal tract.

Hematopoietic cell differentiation from embryonic and induced pluripotent stem cells

PubMed Central

2013-01-01

Pluripotent stem cells, both embryonic stem cells and induced pluripotent stem cells, are undifferentiated cells that can self-renew and potentially differentiate into all hematopoietic lineages, such as hematopoietic stem cells (HSCs), hematopoietic progenitor cells and mature hematopoietic cells in the presence of a suitable culture system. Establishment of pluripotent stem cells provides a comprehensive model to study early hematopoietic development and has emerged as a powerful research tool to explore regenerative medicine. Nowadays, HSC transplantation and hematopoietic cell transfusion have successfully cured some patients, especially in malignant hematological diseases. Owing to a shortage of donors and a limited number of the cells, hematopoietic cell induction from pluripotent stem cells has been regarded as an alternative source of HSCs and mature hematopoietic cells for intended therapeutic purposes. Pluripotent stem cells are therefore extensively utilized to facilitate better understanding in hematopoietic development by recapitulating embryonic development in vivo, in which efficient strategies can be easily designed and deployed for the generation of hematopoietic lineages in vitro. We hereby review the current progress of hematopoietic cell induction from embryonic stem/induced pluripotent stem cells. PMID:23796405

Oocyte exposure to ZnO nanoparticles inhibits early embryonic development through the γ-H2AX and NF-κB signaling pathways

PubMed Central

Liu, Jing; Zhao, Yong; Ge, Wei; Zhang, Pengfei; Liu, Xinqi; Zhang, Weidong; Hao, Yanan; Yu, Shuai; Li, Lan; Chu, Meiqiang; Min, Lingjiang; Zhang, Hongfu; Shen, Wei

2017-01-01

The impacts of zinc oxide nanoparticles on embryonic development following oocyte stage exposure are unknown and the underlying mechanisms are sparsely understood. In the current investigation, intact nanoparticles were detected in ovarian tissue in vivo and cultured cells in vitro under zinc oxide nanoparticles treatment. Zinc oxide nanoparticles exposure during the oocyte stage inhibited embryonic development. Notably, in vitro culture data closely matched in vivo embryonic data, in that the impairments caused by Zinc oxide nanoparticles treatment passed through cell generations; and both gamma-H2AX and NF-kappaB pathways were involved in zinc oxide nanoparticles caused embryo-toxicity. Copper oxide and silicon dioxide nanoparticles have been used to confirm that particles are important for the toxicity of zinc oxide nanoparticles. The toxic effects of zinc oxide nanoparticles emanate from both intact nanoparticles and Zn2+. Our investigation along with others suggests that zinc oxide nanoparticles are toxic to the female reproductive system [ovaries (oocytes)] and subsequently embryo-toxic and that precaution should be taken regarding human exposure to their everyday use. PMID:28487501

Qualitative research of alternatively splice variants of fibronectin in different development stage of mice heart.

PubMed

Lu, Feng; Ma, Fang-Fang; Zhang, Wei; Li, Ying; Wei, Fei-Yu; Zhou, Lei

2015-12-01

Fibronectin (FN) plays vital roles in cell adhesion, differentiation, proliferation and migration. It is involved in the process of embryonic development and is highly conserved during evolution. The EIIIA and EIIIB of FN show a very high degree of homology among vertebrates. Embryos deleting both EIIIA and EIIIB displayed multiple embryonic cardiovascular defects, implying their crucial role during embryogenesis. The correlation of spliced EIIIB, EIIIA, and IIICS of FN to heart development was studied by observing their chronological expression in mice heart. C57 mice embryos at E11.5, E12.5, E13.5, E14.5, E15.5, E16.5, E17.5, E18.5, E19.5 days, postnatal day 1 (P1d), and adult male mice (3 months) were used. For each alternatively spliced FN1 domain (EIIIB, EIIIA and IIICS), primer pairs were designed for specific amplification. Total RNA was extracted from the heart tissue, reverse transcripted to cDNA, followed by RT-PCR with specific primers. The PCR amplification was verified by agarose gel electrophoresis, showing specific fragments of the expected sizes. In adult mice heart, only alternatively splice variants of EIIIA-, EIIIB-, IIICS+ were expressed. While in embryonic mice, spliced variant of EIIIA+/-, EIIIB+/-, IIICS+ were observed. The expression of EIIIA and EIIIB changed during heart development. FN is crucial for the normal development of the embryonic heart by modulating cardiac neural crest (CNC) proliferation and survival, and maintenance of CNC cells. FN1 gene seems to play a significant role by expression of highly conserved EIIIA and EIIIB in embryonic heart development.

Evidence of local adaptation in westslope cutthroat trout

USGS Publications Warehouse

Drinan, Daniel P.; Zale, Alexander V.; Webb, Molly A.H.; Taper, Mark L.; Shepard, Bradley B.; Kalinowski, Steven T.

2012-01-01

An understanding of the process of local adaptation would allow managers to better protect and conserve species. Many salmonids are in need of such efforts, and because they often persist in differing, isolated environments, they are useful organisms for studying local adaptation. In addition, the temperature sensitivity of salmonids provides a likely target for natural selection. We studied thermal adaptation in four wild populations and one hatchery stock of westslope cutthroat trout Oncorhynchus clarkii lewisi . The mean summer temperatures of source streams ranged from 6.7°C to 11.2°C. Embryos were collected from the wild, and embryonic development, embryonic survival, and juvenile growth were determined. A significant relationship between median embryonic survival and source stream temperature was detected. Based on a rank test, populations from colder streams had a greater decline in median embryonic survival at warm temperatures than populations from warmer streams. Embryonic development and juvenile growth did not appear to be influenced by source. These findings suggest that populations are thermally adapted to their source streams and this should be considered by managers. However, further study is necessary to sort out the potential confounding factors, whether genetic or epigenetic.

[Regulation of in vitro and in vivo differentiation of mouse embryonic stem cells, embryonic germ cells, and teratocarcinoma cells by TGFb family signaling factors].

PubMed

Gordeeva, O F; Nikonova, T M; Lifantseva, N V

2009-01-01

The activity of specific signaling and transcription factors determines the cell fate in normal development and in tumor transformation. The transcriptional profiles of gene-components of different branches of TGFbeta family signaling pathways were studied in experimental models of initial stages of three-dimensional in vitro differentiation of embryonic stem cells, embryonic germ cells and teratocarcinoma cells and in teratomas and teratocarcinomas developed after their transplantation into immunodeficient Nude mice. Gene profile analysis of studied cell systems have revealed that expression patterns of ActivinA, Nodal, Lefty1, Lefty2, TGF TGFbeta1, BMP4, and GDF were identical in pluripotent stem cells whereas the mRNAs of all examined genes with the exception of Inhibin betaA/ActivinA were detected in the teratocarcinoma cells. These results indicate that differential activity of signaling pathways of the TGFbeta family factors regulates pluripotent state maintenance and pluripotent stem cell differentiation into the progenitors of three germ layers and extraembryonic structures and that normal expression pattern of TGFbeta family factors is rearranged in embryonic teratocarcinoma cells during tumor growth in vitro and in vivo.

Spatial distribution of endogenous retinoids in the murine embryonic mandible.

PubMed

Kronmiller, J E; Beeman, C S

1994-12-01

Retinoids play an important part in pattern formation during embryonic development. Exogenous retinoids alter the pattern of skeletal, neural and odontogenic tissues. Endogenous retinoids have been demonstrated previously in the murine embryonic mandible, reaching a concentration peak during the initiation of odontogenesis. It was now found that endogenous retinoids are present in a concentration gradient in the embryonic mouse mandible at the time of the initiation of the dental lamina. All-trans-retinoic acid was more concentrated in the incisor region and retinol in the molar region. These results, and the fact that exogenous retinoids produce supernumerary incisors and missing molars, suggest that all-trans-retinoic acid may instruct incisor morphology.

Beneficial effect of resveratrol on bovine oocyte maturation and subsequent embryonic development after in vitro fertilization.

PubMed

Wang, Feng; Tian, XiuZhi; Zhang, Lu; He, ChangJiu; Ji, PengYun; Li, Yu; Tan, DunXian; Liu, GuoShi

2014-02-01

To analyze the potential beneficial effects and mechanisms of action of resveratrol on the maturation of bovine oocytes that were incubated in different concentrations of resveratrol (0.1, 1.0, or 10.0 μM) as germinal vesicle-stage oocytes. In vitro prospective study. University research laboratory. Animal models for human studies. In vitro culture in the presence of various concentrations of the antioxidant resveratrol. Parameters of hormone levels, oocyte nuclear maturation, cumulus expansion, levels of intracellular glutathione and reactive oxygen species, embryonic cleavage, blastocyst formation, gene expression associated with mature bovine oocytes and cumulus cells, and level of sirtuin 1 gene expression. Resveratrol statistically significantly increased progesterone secretion and decreased estradiol-17β secretion by cumulus cells. The elevated levels of progesterone activated the Mos/MEK/p42 mitogen-activated protein kinase (MAPK) cascade in the oocytes. At a concentration of 1.0 μM, resveratrol statistically significantly improved cumulus expansion, polar body formation, the (hatched) blastocyst rate, and the mean number of cells/blastocysts. Meanwhile, resveratrol statistically significantly reduced the level of reactive oxygen species (ROS) and increased the level of glutathione (GSH). For the first time, the expression of the sirtuin-1 gene was identified in granulosa cells, cumulus cells, oocytes, and blastocysts. Further studies revealed that resveratrol promoted sirtuin-1 gene expression. Resveratrol promoted bovine oocyte maturation and subsequent post-in vitro fertilization embryonic development by inducing progesterone secretion and an antioxidant effect, probably in a manner dependent on sirtuin-1. Copyright © 2014 American Society for Reproductive Medicine. All rights reserved.

SLC52A3, A Brown–Vialetto–van Laere syndrome candidate gene is essential for mouse development, but dispensable for motor neuron differentiation

PubMed Central

Intoh, Atsushi; Suzuki, Naoki; Koszka, Kathryn; Eggan, Kevin

2016-01-01

Riboflavin, also known as vitamin B2, is essential for cellular reduction-oxidation reactions, but is not readily synthesized by mammalian cells. It has been proposed that riboflavin absorption occurs through solute carrier family 52 members (SLC52) A1, A2 and A3. These transporters are also candidate genes for the childhood onset-neural degenerative syndrome Brown–Vialetto–Van Laere (BVVL). Although riboflavin is an essential nutrient, why mutations in its transporters result in a neural cell-specific disorder remains unclear. Here, we provide evidence that Slc52a3 is the mouse ortholog of SLC52A3 and show that Slc52a3 deficiency results in early embryonic lethality. Loss of mutant embryos was associated with both defects in placental formation and increased rates of apoptosis in embryonic cells. In contrast, Slc52a3 −/− embryonic stem cell lines could be readily established and differentiated into motor neurons, suggesting that this transporter is dispensable for neural differentiation and short-term maintenance. Consistent with this finding, examination of Slc52a3 gene products in adult tissues revealed expression in the testis and intestine but little or none in the brain and spinal cord. Our results suggest that BVVL patients with SCL52A3 mutations may be good candidates for riboflavin replacement therapy and suggests that either the mutations these individuals carry are hypomorphic, or that in these cases alternative transporters act during human embryogenesis to allow full-term development. PMID:26976849

Embryology of Early Jurassic dinosaur from China with evidence of preserved organic remains.

PubMed

Reisz, Robert R; Huang, Timothy D; Roberts, Eric M; Peng, ShinRung; Sullivan, Corwin; Stein, Koen; LeBlanc, Aaron R H; Shieh, DarBin; Chang, RongSeng; Chiang, ChengCheng; Yang, Chuanwei; Zhong, Shiming

2013-04-11

Fossil dinosaur embryos are surprisingly rare, being almost entirely restricted to Upper Cretaceous strata that record the late stages of non-avian dinosaur evolution. Notable exceptions are the oldest known embryos from the Early Jurassic South African sauropodomorph Massospondylus and Late Jurassic embryos of a theropod from Portugal. The fact that dinosaur embryos are rare and typically enclosed in eggshells limits their availability for tissue and cellular level investigations of development. Consequently, little is known about growth patterns in dinosaur embryos, even though post-hatching ontogeny has been studied in several taxa. Here we report the discovery of an embryonic dinosaur bone bed from the Lower Jurassic of China, the oldest such occurrence in the fossil record. The embryos are similar in geological age to those of Massospondylus and are also assignable to a sauropodomorph dinosaur, probably Lufengosaurus. The preservation of numerous disarticulated skeletal elements and eggshells in this monotaxic bone bed, representing different stages of incubation and therefore derived from different nests, provides opportunities for new investigations of dinosaur embryology in a clade noted for gigantism. For example, comparisons among embryonic femora of different sizes and developmental stages reveal a consistently rapid rate of growth throughout development, possibly indicating that short incubation times were characteristic of sauropodomorphs. In addition, asymmetric radial growth of the femoral shaft and rapid expansion of the fourth trochanter suggest that embryonic muscle activation played an important role in the pre-hatching ontogeny of these dinosaurs. This discovery also provides the oldest evidence of in situ preservation of complex organic remains in a terrestrial vertebrate.

Evaluation of the neurotoxic effects of chronic embryonic exposure with inorganic mercury on motor and anxiety-like responses in zebrafish (Danio rerio) larvae.

PubMed

Abu Bakar, Noraini; Mohd Sata, Nurul Syafida Asma'; Ramlan, Nurul Farhana; Wan Ibrahim, Wan Norhamidah; Zulkifli, Syaizwan Zahmir; Che Abdullah, Che Azurahanim; Ahmad, Syahida; Amal, Mohammad Noor Azmai

Chronic exposure to mercury (Hg) can lead to cumulative impairments in motor and cognitive functions including alteration in anxiety responses. Although several risk factors have been identified in recent year, little is known about the environmental factors that either due exposure toward low level of inorganic mercury that may led to the developmental disorders. The present study investigated the effects of embryonic exposure of mercury chloride on motor function and anxiety-like behavior. The embryo exposed to 6 different concentrations of HgCl 2 (7.5, 15, 30, 100, 125, 250nM) at 5hpf until hatching (72hpf) in a semi-static condition. The mortality rate increased in a dose dependent manner where the chronic embryonic exposure to 100nM decreased the number of tail coiling, heartbeat, and swimming activity. Aversive stimulus was used to examine the effects of 100nM interferes with the development of anxiety-related behavior. No elevation in both thigmotaxis and avoidance response of 6dpf larvae exposed with 100nM were found. Biochemical analysis showed HgCl 2 exposure affects proteins, lipids, carbohydrates and nucleic acids of the zebrafish larvae. These results showed that implication of HgCl 2 on locomotor and biochemical defects affects motor performance and anxiety-like responses. Yet, the potential underlying mechanisms these responses need to be further investigated which is crucial to prevent potential hazards on the developing organism due to neurotoxicant exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

Embryonic Lethality of Mitochondrial Pyruvate Carrier 1 Deficient Mouse Can Be Rescued by a Ketogenic Diet

PubMed Central

Krznar, Petra; Hörl, Manuel; Ammar, Zeinab; Montessuit, Sylvie; Pierredon, Sandra; Zamboni, Nicola; Martinou, Jean-Claude

2016-01-01

Mitochondrial import of pyruvate by the mitochondrial pyruvate carrier (MPC) is a central step which links cytosolic and mitochondrial intermediary metabolism. To investigate the role of the MPC in mammalian physiology and development, we generated a mouse strain with complete loss of MPC1 expression. This resulted in embryonic lethality at around E13.5. Mouse embryonic fibroblasts (MEFs) derived from mutant mice displayed defective pyruvate-driven respiration as well as perturbed metabolic profiles, and both defects could be restored by reexpression of MPC1. Labeling experiments using 13C-labeled glucose and glutamine demonstrated that MPC deficiency causes increased glutaminolysis and reduced contribution of glucose-derived pyruvate to the TCA cycle. Morphological defects were observed in mutant embryonic brains, together with major alterations of their metabolome including lactic acidosis, diminished TCA cycle intermediates, energy deficit and a perturbed balance of neurotransmitters. Strikingly, these changes were reversed when the pregnant dams were fed a ketogenic diet, which provides acetyl-CoA directly to the TCA cycle and bypasses the need for a functional MPC. This allowed the normal gestation and development of MPC deficient pups, even though they all died within a few minutes post-delivery. This study establishes the MPC as a key player in regulating the metabolic state necessary for embryonic development, neurotransmitter balance and post-natal survival. PMID:27176894

Magnetic resonance imaging study of eye congenital birth defects in mouse model

PubMed Central

Tucker, Zachary; Mongan, Maureen; Meng, Qinghang; Xia, Ying

2017-01-01

Purpose Embryonic eyelid closure is a well-documented morphogenetic episode in mammalian eye development. Detection of eyelid closure defect in humans is a major challenge because eyelid closure and reopen occur entirely in utero. As a consequence, congenital eye defects that are associated with failure of embryonic eyelid closure remain unknown. To fill the gap, we developed a mouse model of defective eyelid closure. This preliminary work demonstrates that the magnetic resonance imaging (MRI) approach can be used for the detection of extraocular muscle abnormalities in the mouse model. Methods Mice with either normal (Map3k1+/−) or defective (Map3k1−/−) embryonic eyelid closure were used in this study. Images of the extraocular muscles were obtained with a 9.4 T high resolution microimaging MRI system. The extraocular muscles were identified, segmented, and measured in each imaging slice using an in-house program. Results In agreement with histological findings, the imaging data show that mice with defective embryonic eyelid closure develop less extraocular muscle than normal mice. In addition, the size of the eyeballs was noticeably reduced in mice with defective embryonic eyelid closure. Conclusions We demonstrated that MRI can potentially be used for the study of extraocular muscle in the mouse model of the eye open-at-birth defect, despite the lack of specificity of muscle group provided by the current imaging resolution. PMID:28848319

Long-term in vivo harmonics imaging of zebrafish embryonic development based on a femtosecond Cr:forsterite laser

NASA Astrophysics Data System (ADS)

Chen, S.-Y.; Tsai, T.-H.; Hsieh, C.-S.; Tai, S.-P.; Lin, C.-Y.; Ko, C.-Y.; Chen, Y.-C.; Tsai, H.-J.; Hu, C.-H.; Sun, C.-K.

2005-03-01

Based on a femtosecond Cr:forsterite laser, harmonics optical microscopy (HOM) provides a truly "noninvasive" tool for in vivo and long-term study of vertebrate embryonic development. Based on optical nonlinearity, HOM provides sub-micrometer 3D spatial resolution and high 3D optical-sectioning power without using invasive and toxic fluorophores. Since only virtual-level-transition is involved, HOM is known to leave no energy deposition and no photodamage. Combined with second harmonic generation, which is sensitive to specific structure such as nerve and muscle fibers, HOM can perform functional studies of early developmental dynamics of many vertebrate physiological systems. Recently, zebrafish has become a standard model for many biological and medical studies of vertebrates, due to the similarity between embryonic development of zebrafish and human being. Here we demonstrate in vivo HOM studies of developmental dynamics of several important embryonic physiological systems in live zebrafish embryos, with focuses on the developments of brains, eyes, ears, and hearts. Based on a femtosecond Cr:forsterite laser, which provides the deepest penetration (~1.5mm) and least photodamage in the zebrafish embryo, complete developing processes of different physiological systems within a period of time longer than 20 hours can be non-invasively observed inside the same embryo.

Dysfunction in gap junction intercellular communication induces aberrant behavior of the inner cell mass and frequent collapses of expanded blastocysts in mouse embryos.

PubMed

Togashi, Kazue; Kumagai, Jin; Sato, Emiko; Shirasawa, Hiromitsu; Shimoda, Yuki; Makino, Kenichi; Sato, Wataru; Kumazawa, Yukiyo; Omori, Yasufumi; Terada, Yukihiro

2015-06-01

We investigated the role of gap junctions (GJs) in embryological differentiation, and observed the morphological behavior of the inner cell mass (ICM) by time-lapse movie observation (TLM) with gap junction inhibitors (GJis). ICR mouse embryos were exposed to two types of GJis in CZB medium: oleamide (0 to 50 μM) and 1-heptanol (0 to 10 mM). We compared the rate of blastocyst formation at embryonic day 4.5 (E4.5) with E5.5. We also observed and evaluated the times from the second cleavage to each embryonic developing stage by TLM. We investigated embryonic distribution of DNA, Nanog protein, and Connexin 43 protein with immunofluorescent staining. In the comparison of E4.5 with E5.5, inhibition of gap junction intercellular communication (GJIC) delayed embryonic blastocyst formation. The times from the second cleavage to blastocyst formation were significantly extended in the GJi-treated embryos (control vs with oleamide, 2224 ± 179 min vs 2354 ± 278 min, p = 0.013). Morphological differences were traced in control versus GJi-treated embryos until the hatching stage. Oleamide induced frequent severe collapses of expanded blastocysts (77.4 % versus 26.3 %, p = 0.0001) and aberrant ICM divisions connected to sticky strands (74.3 % versus 5.3 %, p = 0.0001). Immunofluorescent staining indicated Nanog-positive cells were distributed in each divided ICM. GJIC plays an important role in blastocyst formation, collapses of expanded blastocysts, and the ICM construction in mouse embryos.

Adult Human Gingival Epithelial Cells as a Source for Whole-tooth Bioengineering

PubMed Central

Angelova Volponi, A.; Kawasaki, M.; Sharpe, P.T.

2013-01-01

Teeth develop from interactions between embryonic oral epithelium and neural-crest-derived mesenchyme. These cells can be separated into single-cell populations and recombined to form normal teeth, providing a basis for bioengineering new teeth if suitable, non-embryonic cell sources can be identified. We show here that cells can be isolated from adult human gingival tissue that can be expanded in vitro and, when combined with mouse embryonic tooth mesenchyme cells, form teeth. Teeth with developing roots can be produced from this cell combination following transplantation into renal capsules. These bioengineered teeth contain dentin and enamel with ameloblast-like cells and rests of Malassez of human origin. PMID:23458883

Embryonic Heart Progenitors and Cardiogenesis

PubMed Central

Brade, Thomas; Pane, Luna S.; Moretti, Alessandra; Chien, Kenneth R.; Laugwitz, Karl-Ludwig

2013-01-01

The mammalian heart is a highly specialized organ, comprised of many different cell types arising from distinct embryonic progenitor populations during cardiogenesis. Three precursor populations have been identified to contribute to different myocytic and nonmyocytic cell lineages of the heart: cardiogenic mesoderm cells (CMC), the proepicardium (PE), and cardiac neural crest cells (CNCCs). This review will focus on molecular cues necessary for proper induction, expansion, and lineage-specific differentiation of these progenitor populations during cardiac development in vivo. Moreover, we will briefly discuss how the knowledge gained on embryonic heart progenitor biology can be used to develop novel therapeutic strategies for the management of congenital heart disease as well as for improvement of cardiac function in ischemic heart disease. PMID:24086063

EMBRYONIC VASCULAR DISRUPTION ADVERSE OUTCOMES: LINKING HIGH THROUGHPUT SIGNALING SIGNATURES WITH FUNCTIONAL CONSEQUENCES

EPA Science Inventory

Embryonic vascular disruption is an important adverse outcome pathway (AOP) given the knowledge that chemical disruption of early cardiovascular system development leads to broad prenatal defects. High throughput screening (HTS) assays provide potential building blocks for AOP d...

EMBRYONIC PALATAL RESPONSES TO TERATOGENS IN SERUM-FREE ORGAN CULTURE

EPA Science Inventory

This study examines development of rat, mouse and human embryonic palates in submerged, serum-free organ culture. he concentration-response profiles for retinoic acid (RA), triamcinolone (TRI), hydrocortisone (HC), dexamethasone (DEX), and 2,3,7,11- tetrachlorodibenzo-p-dioxin (T...

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.

Normal embryonic stages of the Longnose Gar, Lepisosteus osseus

PubMed Central

Long, Wilbur L; Ballard, William W

2001-01-01

Background Gaps exist in the modern literature that describes patterns of development in living groups of actinopterygian fishes. Relatively recent descriptions of development exist for the teleost fishes, bowfin, sturgeon, paddlefish and bichirs. Such literature dealing with the gars is to be found in older work, done approximately a century ago. The present study concerns the gars, of which the garpike, Lepisosteus osseus, is a representative example. Results The embryonic period of life of this fish is divided, as required for experimentation, into 34 stages, from fertilization to exhaustion of the yolk supply. Diagnostic structural characteristics are cited for each stage, and the rate of development is indicated. Conclusions Three features of development are especially noted that compare or contrast with other members of the Neopterygii, and with the Chondrostei. These are meroblastic cleavage, a well-defined yolk syncytial layer (ysl), and a pit at the posterodorsal edge of the blastoderm, which defines an overhanging dorsal lip. Meroblastic cleavage and the ysl in the garpike show an affinity to those character states in the teleosts, though not with Amia, the other neopterygian fish. The posterodorsal pit and dorsal lip are reminiscent of similar features in the Chondrostei. Lepisosteus is unique among the Neopterygii with respect to this character state. Such comparisons set the stage for a broader understanding of the mechanisms for development in these organisms, and of the evolutionary relationships between them. PMID:11319037

Effects of Temperature on the Termination of Egg Diapause and Post-Diapause Embryonic Development of Galeruca daurica (Coleoptera: Chrysomelidae).

PubMed

Zhou, Xiao-Rong; Gao, Jing-Chun; Pang, Bao-Ping

2016-08-01

Galeruca daurica (Joannis) is a new pest on the grasslands of Inner Mongolia, China. It is univoltine and overwinters in the egg stage. Larvae and adults feed on the foliage of Allium plants. To assess the requirements to terminate egg diapause and subsequent effects on post-diapause development rate, eggs were held at different temperature regimes. Exposure to low temperatures was required to terminate egg diapause. Prolonged exposure (2 mo vs 1 mo) to 5°C and outside ambient conditions (mean temperature: 10.5°C; range: -7.1-21.6°C) enhanced the termination of egg diapause. Prolonged exposure also reduced the time to egg hatch; e.g., eggs held for 2 mo versus 1 mo at 5°C developed more quickly when subsequently placed at warmer temperatures. Egg hatch was observed at 17, 21, 25, and 29°C, but not at 15°C. Regression analysis identified 16.2°C as the minimum temperature for post-diapause development. The temperature requirement to complete embryonic development (from diapause termination to egg hatch) was calculated to be 103.1 to 140.9 degree-days. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of environmental oxygen on development and respiration of Australian lungfish (Neoceratodus forsteri) embryos.

PubMed

Mueller, Casey A; Joss, Jean M P; Seymour, Roger S

2011-10-01

The effects of oxygen partial pressure ([Formula: see text]) on development and respiration were investigated in the eggs of the Australian lungfish, Neoceratodus forsteri. At 20°C, embryonic survival and development was optimal at 15 and 20.9 kPa. Development was slowed at 5 and 10 kPa and embryos did not survive 2 kPa. At lower [Formula: see text], the rate of oxygen consumption also decreased. Embryos responded to hypoxia by hatching at an earlier age and stage of development, and hatching wet and dry gut-free masses were reduced. The role of oxygen conductance ([Formula: see text]) in gas exchange was also examined under selected environmental [Formula: see text] and temperatures. The breakdown of the vitelline membrane changed capsule geometry, allowed water to be absorbed into the perivitelline space and increased capsule [Formula: see text]. This occurred at embryonic stage 32 under all treatments and was largely independent of both [Formula: see text] and temperature (15, 20 and 25°C), demonstrating that capsule [Formula: see text] cannot adaptively respond to altered environmental conditions. The membrane breakdown increased capsule diffusive [Formula: see text] and stabilised perivitelline [Formula: see text], but reduced the convective [Formula: see text] of the perivitelline fluid, as the large perivitelline volume and inadequate convective current resulted in a [Formula: see text] gradient within the egg prior to hatch.

Factors affecting pregnancy rate following nonsurgical embryo transfer in buffalo (Bubalus bubalis): a retrospective study.

PubMed

Misra, A K; Rao, M M; Kasiraj, R; Reddy, N S; Pant, H C

1999-07-01

The objectives of this study were to determine the pregnancy rate and factors affecting it following nonsurgical embryo transfer in buffalo. Donor buffalo were superovulated with FSH, and embryos collected nonsurgically were evaluated for stage of development and quality. They were transferred nonsurgically to 91 recipients on Days 5 to 7 of the natural (n = 52) or induced (n = 39) estrus (estrus = Day 0). The overall pregnancy rate of 24/91(26.4%) was higher than in earlier reports for buffalo but was much lower than in cattle. Pregnancy rates were not affected by season (autumn vs winter), side of transfer (right vs left uterine horn), or type of estrus (spontaneous vs induced). The pregnancy rate was high 11/27(40.7%) when donors and recipients were closely synchronized, while it was compromised when recipients were in estrus at +12 h (1/7, 14.3%) and at -12 h (5/27, 18.5%). Asynchrony beyond 12 h on either side resulted into conception failure. The pregnancy rate tended to increase with the increase in CL size of recipients, while stage of embryonic development had no effect. The transfer of an 8-cell embryo with a 16-cell embryo led to the birth of heterosexual twins, indicating that the uterine milieu of Day 5 to 6 recipients may be tolerated by the out-of-phase 8-cell embryo, at least in the presence of a more mature embryo. Embryo quality had the greatest effect on pregnancy rate as it was higher (P < 0.005) after the transfer of Grade I than Grade III embryos (6/10, 60.0% vs 3/36, 13.9%). Assessment of returns to estrus indicated that among nonpregnant recipients, 17/67 (25.4%) embryos never matured sufficiently to prevent luteolysis through maternal recognition of pregnancy (MRP), while 14/67 (20.8%) embryos probably died following MRP. These results indicate that efforts to increase pregnancy rate following embryo transfer in buffalo should include prevention of luteolysis during the first week of transfer and a reduction in the incidence of embryonic mortality.

Effect of carbaryl on survival and development in Bombina orientalis (Boulenger) embryos.

PubMed

Kang, Han Seung; Park, Chan Jin; Gye, Myung Chan

2010-05-01

Bombina orientalis is one of the most common amphibians in the world and comprise a large proportion of their total number in Korea. B. orientalis, spawns in the farming regions at Spring when the massive application of agricultural chemicals occurs. Carbaryl, carbamate chemical is a slightly to highly toxic insecticide inhibiting acetylcholinesterase. The embryotoxicity and teratogenic effects of carbaryl on B. orientalis embryos were investigated at 5, 10, 50 and 100 muM. The survival rates of embryos at 312 h post fertilization were decreased with concentration dependent manner. Exposure to carbaryl produced 4 types of severe external abnormalities such as bent trunk, thick-set body, bent tail and ventral blister. At 5 muM carbaryl, a dose of no observed effect on embryonic survival, developmental abnormalities were significantly increased. The developmental abnormalities showed in order of frequency with bent trunk, thick-set body, bent tail and ventral blister. This result suggests that carbaryl is detrimental for embryonic survival and teratogenic by causing the axial skeletal defects in B. orientalis embryos.

Human embryonic stem cell phosphoproteome revealed by electron transfer dissociation tandem mass spectrometry

PubMed Central

Swaney, Danielle L.; Wenger, Craig D.; Thomson, James A.; Coon, Joshua J.

2009-01-01

Protein phosphorylation is central to the understanding of cellular signaling, and cellular signaling is suggested to play a major role in the regulation of human embryonic stem (ES) cell pluripotency. Here, we describe the use of conventional tandem mass spectrometry-based sequencing technology—collision-activated dissociation (CAD)—and the more recently developed method electron transfer dissociation (ETD) to characterize the human ES cell phosphoproteome. In total, these experiments resulted in the identification of 11,995 unique phosphopeptides, corresponding to 10,844 nonredundant phosphorylation sites, at a 1% false discovery rate (FDR). Among these phosphorylation sites are 5 localized to 2 pluripotency critical transcription factors—OCT4 and SOX2. From these experiments, we conclude that ETD identifies a larger number of unique phosphopeptides than CAD (8,087 to 3,868), more frequently localizes the phosphorylation site to a specific residue (49.8% compared with 29.6%), and sequences whole classes of phosphopeptides previously unobserved. PMID:19144917

Vitamin K2 biosynthetic enzyme, UBIAD1 is essential for embryonic development of mice.

PubMed

Nakagawa, Kimie; Sawada, Natsumi; Hirota, Yoshihisa; Uchino, Yuri; Suhara, Yoshitomo; Hasegawa, Tomoka; Amizuka, Norio; Okamoto, Tadashi; Tsugawa, Naoko; Kamao, Maya; Funahashi, Nobuaki; Okano, Toshio

2014-01-01

UbiA prenyltransferase domain containing 1 (UBIAD1) is a novel vitamin K2 biosynthetic enzyme screened and identified from the human genome database. UBIAD1 has recently been shown to catalyse the biosynthesis of Coenzyme Q10 (CoQ10) in zebrafish and human cells. To investigate the function of UBIAD1 in vivo, we attempted to generate mice lacking Ubiad1, a homolog of human UBIAD1, by gene targeting. Ubiad1-deficient (Ubiad1(-/-)) mouse embryos failed to survive beyond embryonic day 7.5, exhibiting small-sized body and gastrulation arrest. Ubiad1(-/-) embryonic stem (ES) cells failed to synthesize vitamin K2 but were able to synthesize CoQ9, similar to wild-type ES cells. Ubiad1(+/-) mice developed normally, exhibiting normal growth and fertility. Vitamin K2 tissue levels and synthesis activity were approximately half of those in the wild-type, whereas CoQ9 tissue levels and synthesis activity were similar to those in the wild-type. Similarly, UBIAD1 expression and vitamin K2 synthesis activity of mouse embryonic fibroblasts prepared from Ubiad1(+/-) E15.5 embryos were approximately half of those in the wild-type, whereas CoQ9 levels and synthesis activity were similar to those in the wild-type. Ubiad1(-/-) mouse embryos failed to be rescued, but their embryonic lifespans were extended to term by oral administration of MK-4 or CoQ10 to pregnant Ubiad1(+/-) mice. These results suggest that UBIAD1 is responsible for vitamin K2 synthesis but may not be responsible for CoQ9 synthesis in mice. We propose that UBIAD1 plays a pivotal role in embryonic development by synthesizing vitamin K2, but may have additional functions beyond the biosynthesis of vitamin K2.

CITED1 Expression in Liver Development and Hepatoblastoma12

PubMed Central

Murphy, Andrew J; de Caestecker, Christian; Pierce, Janene; Boyle, Scott C; Ayers, Gregory D; Zhao, Zhiguo; Libes, Jaime M; Correa, Hernan; Walter, Teagan; Huppert, Stacey S; Perantoni, Alan O; de Caestecker, Mark P; Lovvorn, Harold N

2012-01-01

Hepatoblastoma, the most common pediatric liver cancer, consists of epithelial mixed embryonal/fetal (EMEF) and pure fetal histologic subtypes, with the latter exhibiting a more favorable prognosis. Few embryonal histology markers that yield insight into the biologic basis for this prognostic discrepancy exist. CBP/P-300 interacting transactivator 1 (CITED1), a transcriptional co-activator, is expressed in the self-renewing nephron progenitor population of the developing kidney and broadly in its malignant analog, Wilms tumor (WT). In this current study, CITED1 expression is detected in mouse embryonic liver initially on post-coitum day 10.5 (e10.5), begins to taper by e14.5, and is undetectable in e18.5 and adult livers. CITED1 expression is detected in regenerating murine hepatocytes following liver injury by partial hepatectomy and 3,5-diethoxycarbonyl-1,4-dihydrocollidine. Importantly, while CITED1 is undetectable in normal human adult livers, 36 of 41 (87.8%) hepatoblastoma specimens express CITED1, where it is enriched in EMEF specimens compared to specimens of pure fetal histology. CITED1 overexpression in Hep293TT human hepatoblastoma cells induces cellular proliferation and upregulates the Wnt inhibitors Kringle containing transmembrane protein 1 (KREMEN1) and CXXC finger protein 4 (CXXC4). CITED1 mRNA expression correlates with expression of CXXC4 and KREMEN1 in clinical hepatoblastoma specimens. These data show that CITED1 is expressed during a defined time course of liver development and is no longer expressed in the adult liver but is upregulated in regenerating hepatocytes following liver injury. Moreover, as in WT, this embryonic marker is reexpressed in hepatoblastoma and correlates with embryonal histology. These findings identify CITED1 as a novel marker of hepatic progenitor cells that is re-expressed following liver injury and in embryonic liver tumors. PMID:23308048

Cell differentiation: therapeutical challenges in diabetes.

PubMed

Roche, Enrique; Vicente-Salar, Nestor; Arribas, Maribel; Paredes, Beatriz

2012-01-01

Stem cells, derived from either embryonic or adult tissues, are considered to be potential sources of insulin-secreting cells to be transplanted into type 1 and advanced stages of type 2 diabetic patients. Many laboratories have considered this possibility, resulting in a large amount of published protocols, with a wide degree of complexity among them. Our group was the first to report that it was possible to obtain insulin-secreting cells from mouse embryonic stem cells, proving the feasibility of this new challenge. The same observation was immediately reported using human embryonic stem cells. However, the resulting cell product was not properly characterised, affecting the reproducibility of the protocol by other groups. A more elaborated protocol was developed by Lumelsky and co-workers, demonstrating that neuroectodermal cells could be an alternative source for insulin-producing cells. However, the resulting cells of this protocol produced low amounts of the hormone. This aimed other groups to perform key changes in order to improve the insulin content of the resulting cells. Recently, Baetge's group has published a new protocol based on the knowledge accumulated in pancreatic development. In this protocol, human embryonic stem cells were differentiated into islet-like structures through a five step protocol, emulating the key steps during embryonic development of the endocrine pancreas. The final cell product, however, seemed to be in an immature state, thus further improvement is required. Despite this drawback, the protocol represents the culmination of work performed by different groups and offers new research challenges for the investigators in this exciting field. Concerning adult stem cells, the possibility of identifying pancreatic precursors or of reprogramming extrapancreatic derived cells are key possibilities that may circumvent the problems that appear when using embryonic stem cells, such as immune rejection and tumour formation.

Microfluidic chest cavities reveal that transmural pressure controls the rate of lung development.

PubMed

Nelson, Celeste M; Gleghorn, Jason P; Pang, Mei-Fong; Jaslove, Jacob M; Goodwin, Katharine; Varner, Victor D; Miller, Erin; Radisky, Derek C; Stone, Howard A

2017-12-01

Mechanical forces are increasingly recognized to regulate morphogenesis, but how this is accomplished in the context of the multiple tissue types present within a developing organ remains unclear. Here, we use bioengineered 'microfluidic chest cavities' to precisely control the mechanical environment of the fetal lung. We show that transmural pressure controls airway branching morphogenesis, the frequency of airway smooth muscle contraction, and the rate of developmental maturation of the lungs, as assessed by transcriptional analyses. Time-lapse imaging reveals that branching events are synchronized across distant locations within the lung, and are preceded by long-duration waves of airway smooth muscle contraction. Higher transmural pressure decreases the interval between systemic smooth muscle contractions and increases the rate of morphogenesis of the airway epithelium. These data reveal that the mechanical properties of the microenvironment instruct crosstalk between different tissues to control the development of the embryonic lung. © 2017. Published by The Company of Biologists Ltd.

Lamin A/C Haploinsufficiency Modulates the Differentiation Potential of Mouse Embryonic Stem Cells

PubMed Central

Sehgal, Poonam; Chaturvedi, Pankaj; Kumaran, R. Ileng; Kumar, Satish; Parnaik, Veena K.

2013-01-01

Background Lamins are structural proteins that are the major determinants of nuclear architecture and play important roles in various nuclear functions including gene regulation and cell differentiation. Mutations in the human lamin A gene cause a spectrum of genetic diseases that affect specific tissues. Most available mouse models for laminopathies recapitulate disease symptoms for muscle diseases and progerias. However, loss of human lamin A/C also has highly deleterious effects on fetal development. Hence it is important to understand the impact of lamin A/C expression levels on embryonic differentiation pathways. Methodology and Principal Findings We have investigated the differentiation potential of mouse embryonic stem cells containing reduced levels of lamin A/C by detailed lineage analysis of embryoid bodies derived from these cells by in vitro culture. We initially carried out a targeted disruption of one allele of the mouse lamin A/C gene (Lmna). Undifferentiated wild-type and Lmna+/− embryonic stem cells showed similar expression of pluripotency markers and cell cycle profiles. Upon spontaneous differentiation into embryoid bodies, markers for visceral endoderm such as α-fetoprotein were highly upregulated in haploinsufficient cells. However, neuronal markers such as β-III tubulin and nestin were downregulated. Furthermore, we observed a reduction in the commitment of Lmna+/− cells into the myogenic lineage, but no discernible effects on cardiac, adipocyte or osteocyte lineages. In the next series of experiments, we derived embryonic stem cell clones expressing lamin A/C short hairpin RNA and examined their differentiation potential. These cells expressed pluripotency markers and, upon differentiation, the expression of lineage-specific markers was altered as observed with Lmna+/− embryonic stem cells. Conclusions We have observed significant effects on embryonic stem cell differentiation to visceral endoderm, neuronal and myogenic lineages upon depletion of lamin A/C. Hence our results implicate lamin A/C level as an important determinant of lineage-specific differentiation during embryonic development. PMID:23451281

Identification of a small molecule that facilitates the differentiation of human iPSCs/ESCs and mouse embryonic pancreatic explants into pancreatic endocrine cells.

PubMed

Kondo, Yasushi; Toyoda, Taro; Ito, Ryo; Funato, Michinori; Hosokawa, Yoshiya; Matsui, Satoshi; Sudo, Tomomi; Nakamura, Masahiro; Okada, Chihiro; Zhuang, Xiaotong; Watanabe, Akira; Ohta, Akira; Inagaki, Nobuya; Osafune, Kenji

2017-08-01

Pancreatic beta-like cells generated from human induced pluripotent stem cells (hiPSCs) or human embryonic stem cells (hESCs) offer an appealing donor tissue source. However, differentiation protocols that mainly use growth factors are costly. Therefore, in this study, we aimed to establish efficient differentiation protocols to change hiPSCs/hESCs to insulin (INS) + cells using novel small-molecule inducers. We screened small molecules that increased the induction rate of INS + cells from hESC-derived pancreatic and duodenal homeobox 1 (PDX1) + pancreatic progenitor cells. The differentiation protocol to generate INS + cells from hiPSCs/hESCs was optimised using hit compounds, and INS + cells induced with the compounds were characterised for their in vitro and in vivo functions. The inducing activity of the hit compounds was also examined using mouse embryonic pancreatic tissues in an explant culture system. Finally, RNA sequencing analyses were performed on the INS + cells to elucidate the mechanisms of action by which the hit compounds induced pancreatic endocrine differentiation. One hit compound, sodium cromoglicate (SCG), was identified out of approximately 1250 small molecules screened. When SCG was combined with a previously described protocol, the induction rate of INS + cells increased from a mean ± SD of 5.9 ± 1.5% (n = 3) to 16.5 ± 2.1% (n = 3). SCG induced neurogenin 3-positive cells at a mean ± SD of 32.6 ± 4.6% (n = 3) compared with 14.2 ± 3.6% (n = 3) for control treatment without SCG, resulting in an increased generation of endocrine cells including insulin-producing cells. Similar induction by SCG was confirmed using mouse embryonic pancreatic explants. We also confirmed that the mechanisms of action by which SCG induced pancreatic endocrine differentiation included the inhibition of bone morphogenetic protein 4 signalling. SCG improves the generation of pancreatic endocrine cells from multiple hiPSC/hESC lines and mouse embryonic pancreatic explants by facilitating the differentiation of endocrine precursors. This discovery will contribute to elucidating the mechanisms of pancreatic endocrine development and facilitate cost-effective generation of INS + cells from hiPSCs/hESCs. The RNA sequencing data generated during the current study are available in the Gene Expression Omnibus ( www.ncbi.nlm.nih.gov/geo ) with series accession number GSE89973.

Diversity and Complexity in Chromatin Recognition by TFII-I Transcription Factors in Pluripotent Embryonic Stem Cells and Embryonic Tissues

PubMed Central

Makeyev, Aleksandr V.; Enkhmandakh, Badam; Hong, Seung-Hyun; Joshi, Pujan; Shin, Dong-Guk; Bayarsaihan, Dashzeveg

2012-01-01

GTF2I and GTF2IRD1 encode a family of closely related transcription factors TFII-I and BEN critical in embryonic development. Both genes are deleted in Williams-Beuren syndrome, a complex genetic disorder associated with neurocognitive, craniofacial, dental and skeletal abnormalities. Although genome-wide promoter analysis has revealed the existence of multiple TFII-I binding sites in embryonic stem cells (ESCs), there was no correlation between TFII-I occupancy and gene expression. Surprisingly, TFII-I recognizes the promoter sequences enriched for H3K4me3/K27me3 bivalent domain, an epigenetic signature of developmentally important genes. Moreover, we discovered significant differences in the association between TFII-I and BEN with the cis-regulatory elements in ESCs and embryonic craniofacial tissues. Our data indicate that in embryonic tissues BEN, but not the highly homologous TFII-I, is primarily recruited to target gene promoters. We propose a “feed-forward model” of gene regulation to explain the specificity of promoter recognition by TFII-I factors in eukaryotic cells. PMID:22970219

Diversity and complexity in chromatin recognition by TFII-I transcription factors in pluripotent embryonic stem cells and embryonic tissues.

PubMed

Makeyev, Aleksandr V; Enkhmandakh, Badam; Hong, Seung-Hyun; Joshi, Pujan; Shin, Dong-Guk; Bayarsaihan, Dashzeveg

2012-01-01

GTF2I and GTF2IRD1 encode a family of closely related transcription factors TFII-I and BEN critical in embryonic development. Both genes are deleted in Williams-Beuren syndrome, a complex genetic disorder associated with neurocognitive, craniofacial, dental and skeletal abnormalities. Although genome-wide promoter analysis has revealed the existence of multiple TFII-I binding sites in embryonic stem cells (ESCs), there was no correlation between TFII-I occupancy and gene expression. Surprisingly, TFII-I recognizes the promoter sequences enriched for H3K4me3/K27me3 bivalent domain, an epigenetic signature of developmentally important genes. Moreover, we discovered significant differences in the association between TFII-I and BEN with the cis-regulatory elements in ESCs and embryonic craniofacial tissues. Our data indicate that in embryonic tissues BEN, but not the highly homologous TFII-I, is primarily recruited to target gene promoters. We propose a "feed-forward model" of gene regulation to explain the specificity of promoter recognition by TFII-I factors in eukaryotic cells.

Alterations in the developing testis transcriptome following embryonic vinclozolin exposure.

PubMed

Clement, Tracy M; Savenkova, Marina I; Settles, Matthew; Anway, Matthew D; Skinner, Michael K

2010-11-01

The current study investigates the direct effects of in utero vinclozolin exposure on the developing F1 generation rat testis transcriptome. Previous studies have demonstrated that exposure to vinclozolin during embryonic gonadal sex determination induces epigenetic modifications of the germ line and transgenerational adult onset disease states. Microarray analyses were performed to compare control and vinclozolin treated testis transcriptomes at embryonic days 13, 14 and 16. A total of 576 differentially expressed genes were identified and the major cellular functions and pathways associated with these altered transcripts were examined. The sets of regulated genes at the different development periods were found to be transiently altered and distinct. Categorization by major known functions of altered genes was performed. Specific cellular process and pathway analyses suggest the involvement of Wnt and calcium signaling, vascular development and epigenetic mechanisms as potential mediators of the direct F1 generation actions of vinclozolin. Copyright © 2010 Elsevier Inc. All rights reserved.

ALTERATIONS IN THE DEVELOPING TESTIS TRANSCRIPTOME FOLLOWING EMBRYONIC VINCLOZOLIN EXPOSURE

PubMed Central

Clement, Tracy M.; Savenkova, Marina I.; Settles, Matthew; Anway, Matthew D.; Skinner, Michael K.

2010-01-01

The current study investigates the direct effects of in utero vinclozolin exposure on the developing F1 generation rat testis transcriptome. Previous studies have demonstrated that exposure to vinclozolin during embryonic gonadal sex determination induces epigenetic modifications of the germ line and transgenerational adult onset disease states. Microarray analyses were performed to compare control and vinclozolin treated testis transcriptomes at embryonic day 13, 14 and 16. A total of 576 differentially expressed genes were identified and the major cellular functions and pathways associated with these altered transcripts were examined. The sets of regulated genes at the different development periods were found to be transiently altered and distinct. Categorization by major known functions of altered genes was performed. Specific cellular process and pathway analyses suggest the involvement of Wnt and calcium signaling, vascular development and epigenetic mechanisms as potential mediators of the direct F1 generation actions of vinclozolin. PMID:20566332

Characterizing the distribution of steroid sulfatase during embryonic development: when and where might metabolites of maternal steroids be reactivated?

PubMed

Paitz, Ryan T; Duffield, Kristin R; Bowden, Rachel M

2017-12-15

All vertebrate embryos are exposed to maternally derived steroids during development. In placental vertebrates, metabolism of maternal steroids by the placenta modulates embryonic exposure, but how exposure is regulated in oviparous vertebrates is less clear. Recent work in oviparous vertebrates has demonstrated that steroids are not static molecules, as they can be converted to more polar steroid sulfates by sulfotransferase enzymes. Importantly, these steroid sulfates can be converted back to the parent compound by the enzyme steroid sulfatase (STS). We investigated when and where STS was present during embryonic development in the red-eared slider turtle, Trachemys scripta We report that STS is present during all stages of development and in all tissues we examined. We conclude that STS activity may be particularly important for regulating maternal steroid exposure in oviparous vertebrates. © 2017. Published by The Company of Biologists Ltd.

Mirror-image duplication of the primary axis and heart in Xenopus embryos by the overexpression of Msx-1 gene.

PubMed

Chen, Y; Solursh, M

1995-10-01

The Msx-1 gene (formerly known as Hox-7) is a member of a discrete subclass of homeobox-containing genes. Examination of the expression pattern of Msx-1 in murine and avian embryos suggests that this gene may be involved in the regionalization of the medio-lateral axis during earlier development. We have examined the possible functions of Xenopus Msx-1 during early Xenopus embryonic development by overexpression of the Msx-1 gene. Overexpression of Msx-1 causes a left-right mirror-image duplication of primary axial structures, including notochord, neural tube, somites, suckers, and foregut. The embryonic developing heart is also mirror-image duplicated, including looping directions and polarity. These results indicate that Msx-1 may be involved in the mesoderm formation as well as left-right patterning in the early Xenopus embryonic development.

Watch-ing out for chick limb development.

PubMed

Pascoal, Susana; Palmeirim, Isabel

2007-09-01

Time control is a crucial issue during embryonic development. Nevertheless, little is known about how embryonic cells measure time. Until recently, the only molecular clock known to operate during vertebrate embryonic development was the somitogenesis clock, exclusively functioning in coordinating the precise timing of each new pair of somites formed from the presomitic mesoderm. We have recently evidenced that a similar molecular clock also underlies the timing at which autopod chondrogenic precursors are laid down to form a skeletal limb element. In addition, we herein suggest that the molecular clock is not the only parallelism that can be established between somitogenesis and limb-bud development. In an evolutionary perspective, we support the previously proposed idea that the molecular mechanisms involved in the segmentation of the body axis may have been partially reused in the mesoderm of the lateral plate, thereby allowing the emergence of paired appendages.

The effects of 1α, 25-dihydroxyvitamin D3 and transforming growth factor-β3 on bone development in an ex vivo organotypic culture system of embryonic chick femora.

PubMed

Smith, Emma L; Rashidi, Hassan; Kanczler, Janos M; Shakesheff, Kevin M; Oreffo, Richard O C

2015-01-01

Transforming growth factor-beta3 (TGF-β3) and 1α,25-dihydroxyvitamin D3 (1α,25 (OH) 2D3) are essential factors in chondrogenesis and osteogenesis respectively. These factors also play a fundamental role in the developmental processes and the maintenance of skeletal integrity, but their respective direct effects on these processes are not fully understood. Using an organotypic bone rudiment culture system the current study has examined the direct roles the osteotropic factors 1α,25 (OH)2D3 and TGF-β3 exert on the development and modulation of the three dimensional structure of the embryonic femur. Isolated embryonic chick femurs (E11) were organotypically cultured for 10 days in basal media, or basal media supplemented with either 1α,25 (OH) 2D3 (25 nM) or TGF-β3 (5 ng/mL & 15 ng/mL). Analyses of the femurs were undertaken using micro-computed tomography (μCT), histology and immunohistochemistry. 1α,25 (OH)2D3 supplemented cultures enhanced osteogenesis directly in the developing femurs with elevated levels of osteogenic markers such as type 1 collagen. In marked contrast organotypic femur cultures supplemented with TGF-β3 (5 ng/mL & 15 ng/mL) demonstrated enhanced chondrogenesis with a reduction in osteogenesis. These studies demonstrate the efficacy of the ex vivo organotypic embryonic femur culture employed to elucidate the direct roles of these molecules, 1α,25 (OH) 2D3 and TGF-β3 on the structural development of embryonic bone within a three dimensional framework. We conclude that 1α,25(OH)2D and TGF-β3 modify directly the various cell populations in bone rudiment organotypic cultures effecting tissue metabolism resulting in significant changes in embryonic bone growth and modulation. Understanding the roles of osteotropic agents in the process of skeletal development is integral to developing new strategies for the recapitulation of bone tissue in later life.

Differential developmental ability of embryos cloned from tissue-specific stem cells.

PubMed

Inoue, Kimiko; Noda, Shinichi; Ogonuki, Narumi; Miki, Hiromi; Inoue, Shinichi; Katayama, Kazufumi; Mekada, Kazuyuki; Miyoshi, Hiroyuki; Ogura, Atsuo

2007-05-01

Although cloning animals by somatic cell nuclear transfer is generally inefficient, the use of certain nuclear donor cell types may significantly improve or deteriorate outcomes. We evaluated whether two multipotent stem cell lines produced in vitro--neural stem cells (NSCs) and mesenchymal stem cells (MSCs)--could serve as nuclear donors for nuclear transfer cloning. Most (76%) NSC-derived embryos survived the two-cell-to-four-cell transition, the stage when the major zygotic gene activation occurs. Consistent with this observation, the expression patterns of zygotically active genes were better in NSC-derived embryos than in fibroblast clone embryos, which arrested at the two-cell stage more frequently. Embryo transfer experiments demonstrated that at least some of these NSC embryos had the ability to develop to term fetuses (1.6%, 3/189). In contrast, embryos reconstructed using MSCs showed a low rate of in vitro development and never underwent implantation in vivo. Chromosomal analysis of the donor MSCs revealed very frequent aneuploidy, which probably impaired the potential for development of their derived clones. This is the first demonstration that tissue-specific multipotent stem cells produced in vitro can serve as donors of nuclei for cloning mice; however, these cells may be prone to chromosomal aberrations, leading to high embryonic death rates. We found previously that hematopoietic stem cells (HSCs) are very inefficient donor cells because of their failure to activate the genes essential for embryonic development. Taken together, our data led us to conclude that tissue-specific stem cells in mice, namely NSCs, MSCs, and HSCs, exhibited marked variations in the ability to produce cloned offspring and that this ability varies according to both the epigenetic and genetic status of the original genomes. Disclosure of potential conflicts of interest is found at the end of this article.

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.

Knockout of the PKN Family of Rho Effector Kinases Reveals a Non-redundant Role for PKN2 in Developmental Mesoderm Expansion

PubMed Central

Quétier, Ivan; Marshall, Jacqueline J.T.; Spencer-Dene, Bradley; Lachmann, Sylvie; Casamassima, Adele; Franco, Claudio; Escuin, Sarah; Worrall, Joseph T.; Baskaran, Priththivika; Rajeeve, Vinothini; Howell, Michael; Copp, Andrew J.; Stamp, Gordon; Rosewell, Ian; Cutillas, Pedro; Gerhardt, Holger; Parker, Peter J.; Cameron, Angus J.M.

2016-01-01

Summary In animals, the protein kinase C (PKC) family has expanded into diversely regulated subgroups, including the Rho family-responsive PKN kinases. Here, we describe knockouts of all three mouse PKN isoforms and reveal that PKN2 loss results in lethality at embryonic day 10 (E10), with associated cardiovascular and morphogenetic defects. The cardiovascular phenotype was not recapitulated by conditional deletion of PKN2 in endothelial cells or the developing heart. In contrast, inducible systemic deletion of PKN2 after E7 provoked collapse of the embryonic mesoderm. Furthermore, mouse embryonic fibroblasts, which arise from the embryonic mesoderm, depend on PKN2 for proliferation and motility. These cellular defects are reflected in vivo as dependence on PKN2 for mesoderm proliferation and neural crest migration. We conclude that failure of the mesoderm to expand in the absence of PKN2 compromises cardiovascular integrity and development, resulting in lethality. PMID:26774483

Knockout of the PKN Family of Rho Effector Kinases Reveals a Non-redundant Role for PKN2 in Developmental Mesoderm Expansion.

PubMed

Quétier, Ivan; Marshall, Jacqueline J T; Spencer-Dene, Bradley; Lachmann, Sylvie; Casamassima, Adele; Franco, Claudio; Escuin, Sarah; Worrall, Joseph T; Baskaran, Priththivika; Rajeeve, Vinothini; Howell, Michael; Copp, Andrew J; Stamp, Gordon; Rosewell, Ian; Cutillas, Pedro; Gerhardt, Holger; Parker, Peter J; Cameron, Angus J M

2016-01-26

In animals, the protein kinase C (PKC) family has expanded into diversely regulated subgroups, including the Rho family-responsive PKN kinases. Here, we describe knockouts of all three mouse PKN isoforms and reveal that PKN2 loss results in lethality at embryonic day 10 (E10), with associated cardiovascular and morphogenetic defects. The cardiovascular phenotype was not recapitulated by conditional deletion of PKN2 in endothelial cells or the developing heart. In contrast, inducible systemic deletion of PKN2 after E7 provoked collapse of the embryonic mesoderm. Furthermore, mouse embryonic fibroblasts, which arise from the embryonic mesoderm, depend on PKN2 for proliferation and motility. These cellular defects are reflected in vivo as dependence on PKN2 for mesoderm proliferation and neural crest migration. We conclude that failure of the mesoderm to expand in the absence of PKN2 compromises cardiovascular integrity and development, resulting in lethality. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Characteristics and incidence of large eggs in Trichuris muris.

PubMed

Koyama, Koichi

2013-05-01

The production of small numbers of large eggs among the standard-sized eggs of Trichuris trichiura is well known. Large eggs have also been observed in Trichuris muris, but they have not been studied previously. This paper compares the characteristics of the large eggs (LEs, ≥74.5 μm long) and standard-sized eggs (SEs, <74.5 μm long) in cultures of T. muris. Among 112,554 cultured eggs, LEs occurred at very low frequency (0.03 %, i.e., about three large eggs per 10(4) cultured eggs). Embryonated eggs represented 93.72 % of SEs, but only 25.00 % of LEs were embryonated. Embryonated LEs and SEs contained fully matured larvae. An atypical category of unembryonated egg, which contained an incompletely developed larva, an abnormal larva, or granular components, was common among the LEs. However, similar atypical unembryonated SEs were rarely observed. These observations suggest that the LEs that occur very infrequently in T. muris result from an abnormality of embryonation (larval development).

Toxicological effects of mainstream whole smoke solutions on embryonic movements of the developing embryo.

PubMed

Ejaz, Sohail; Seok, Kim Bum; Woong, Lim Chae

2005-01-01

Cigarette smoking is unrivaled among developmental toxicants in terms of total adverse impact on the human population. Maternal tobacco use during pregnancy adversely affects prenatal and postnatal growth and increases the risk of behavioral and developmental defects in children and adolescents. In the current study, the effects of different preparations of nicotine and mainstream whole smoke solutions (MSWSS) on embryonic movements during neonatal development were examined in vivo, using the chicken embryo model, recorded in real-time by a video camera. It was observed that low doses of nicotine induced hyperactivity and higher doses induced hypoactivity. Accordingly, a significant (p < 0.01) decrease in movements was observed by application of 10 microg of nicotine and different preparations of MSWSS. A dose-dependent decrease in embryonic movements was observed, which did not recover by the end of experiment. It was concluded that nicotine could alter embryonic movements, which are important during embryogenesis for differentiation and maturation of the body systems.

A structure-based extracellular matrix expansion mechanism of fibrous tissue growth

PubMed Central

Kalson, Nicholas S; Lu, Yinhui; Taylor, Susan H; Starborg, Tobias; Holmes, David F; Kadler, Karl E

2015-01-01

Embryonic growth occurs predominately by an increase in cell number; little is known about growth mechanisms later in development when fibrous tissues account for the bulk of adult vertebrate mass. We present a model for fibrous tissue growth based on 3D-electron microscopy of mouse tendon. We show that the number of collagen fibrils increases during embryonic development and then remains constant during postnatal growth. Embryonic growth was explained predominately by increases in fibril number and length. Postnatal growth arose predominately from increases in fibril length and diameter. A helical crimp structure was established in embryogenesis, and persisted postnatally. The data support a model where the shape and size of tendon is determined by the number and position of embryonic fibroblasts. The collagen fibrils that these cells synthesise provide a template for postnatal growth by structure-based matrix expansion. The model has important implications for growth of other fibrous tissues and fibrosis. DOI: http://dx.doi.org/10.7554/eLife.05958.001 PMID:25992598

RIPK3 Mediates Necroptosis during Embryonic Development and Postnatal Inflammation in Fadd-Deficient Mice.

PubMed

Zhao, Qun; Yu, XianJun; Zhang, HaiWei; Liu, YongBo; Zhang, XiXi; Wu, XiaoXia; Xie, Qun; Li, Ming; Ying, Hao; Zhang, Haibing

2017-04-25

RIPK3 mediates cell death and regulates inflammatory responses. Although genetic studies have suggested that RIPK3-MLKL-mediated necroptosis leads to embryonic lethality in Fadd or Caspase-8-deficient mice, the exact mechanisms are not fully understood. Here, we generated Ripk3 mutant mice by altering the RIPK3 kinase domain (Ripk3 Δ/Δ mice), thus abolishing its kinase activity. Ripk3 Δ/Δ cells were resistant to necroptosis stimulation in vitro, and Ripk3 Δ/Δ mice were protected from necroptotic diseases. Although the Ripk3 Δ/Δ mutation rescued embryonic lethality in Fadd -/- embryos, Fadd -/- Ripk3 Δ/Δ mice died within 1 day after birth due to massive inflammation. These results indicate that Ripk3 ablation rescues embryonic lethality in Fadd-deficient mice by suppressing two RIPK3-mediating processes: necroptosis during embryogenesis and inflammation during postnatal development in Fadd -/- mice. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

[Recent contributions to the establishment of the axes of the mammalian embryo].

PubMed

Catala, M

2002-06-01

The study of the establishment of embryonic axes during early development has shown that this process is a very early event (occurRing either during ovogenesis or during fertilization) for invertebrates and for lower vertebrates. In mammals, it was considered that this establishment appears late during development because of the great plasticity of blastomeres. Recent data in the mouse embryon show that the mammalian ovocyte is a polarized cell, the polar body corresponding to the animal pole of this cell. The blastomeres that are generated by the zygote divide asynchronously. The first that divides is the one which inherits the plasma cell membrane where fertilization takes place. This blastomere will preferentially give rise to the cells of the embryonic pole of the blastocyst whereas the other yields the cells of the abembryonic pole. The mammalian ovocyte is thus a polarized cell with an already established animal-vegetal axis. The point of sperm entry will determine the embryonic-abembryonic axis.

Improving the cytoplasmic maturation of bovine oocytes matured in vitro with intracellular and/or extracellular antioxidants is not associated with increased rates of embryo development.

PubMed

Rocha-Frigoni, Nathália A S; Leão, Beatriz C S; Dall'Acqua, Priscila Chediek; Mingoti, Gisele Z

2016-11-01

The production of reactive oxygen species (ROS) is a normal process that occurs in the cellular mitochondrial respiratory chain. However, an increase in ROS levels during in vitro production of bovine embryos induces oxidative stress, leading to failed embryonic development. Therefore, we investigated whether supplementation of IVM medium with intracellular (cysteine and cysteamine; C + C) and/or extracellular (catalase; CAT) antioxidants improves the culture system, affects the mitochondrial membrane potential, affects the intracellular levels of ROS and glutathione (GSH) in the bovine oocytes at the end of maturation, and thereby affects the subsequent embryonic development. At the end of IVM, the metaphase II rates were unaffected by the treatments (76.7 ± 1.7% to 80.6 ± 5.2%; P > 0.05). The intracellular ROS levels, expressed in arbitrary fluorescence units, found in the oocytes treated with intracellular antioxidants (C + C and C + C + CAT groups; 1.06, averaged) were as low as those observed in immature oocytes (0 hour: 1.00 ± 0.12). Among mature oocytes, higher (P < 0.05) ROS levels were found in the control group (1.91 ± 0.10) when compared to the ROS levels found in oocytes treated with antioxidants. Intracellular GSH levels in all groups were lower (0.17 ± 0.09 to 0.51 ± 0.05; P < 0.05) than those in immature oocytes (1.00 ± 0.08), although GSH levels in the C + C group (0.51 ± 0.05) were greater (P < 0.05) than in the control, CAT, and C + C + CAT groups (0.23; averaged). The mitochondrial membrane potential in all groups was improved (1.6; averaged; P < 0.05) compared to the membrane potential observed in the immature oocytes (1.00 ± 0.05), with the exception of the C + C group (0.94 ± 0.03). There was no effect (P > 0.05) of antioxidant supplementation on embryonic development to the blastocyst stage (36.1%; averaged); however, there was an increased tendency (P = 0.0689) to obtain a higher blastocyst rate for the C + C + CAT group (47.5 ± 5.6%) compared to the control group (29.9 ± 4.8%). In conclusion, despite improvements in specific parameters of cytoplasmic maturation, the addition of intracellular and/or extracellular antioxidants during IVM did not affect embryo development. Copyright © 2016 Elsevier Inc. All rights reserved.

Redox environment in stem and differentiated cells: A quantitative approach.

PubMed

Lyublinskaya, O G; Ivanova, Ju S; Pugovkina, N A; Kozhukharova, I V; Kovaleva, Z V; Shatrova, A N; Aksenov, N D; Zenin, V V; Kaulin, Yu A; Gamaley, I A; Nikolsky, N N

2017-08-01

Stem cells are believed to maintain a specific intracellular redox status through a combination of enhanced removal capacity and limited production of ROS. In the present study, we challenge this assumption by developing a quantitative approach for the analysis of the pro- and antioxidant ability of human embryonic stem cells in comparison with their differentiated descendants, as well as adult stem and non-stem cells. Our measurements showed that embryonic stem cells are characterized by low ROS level, low rate of extracellular hydrogen peroxide removal and low threshold for peroxide-induced cytotoxicity. However, biochemical normalization of these parameters to cell volume/protein leads to matching of normalized values in stem and differentiated cells and shows that tested in the present study cells (human embryonic stem cells and their fibroblast-like progenies, adult mesenchymal stem cells, lymphocytes, HeLa) maintain similar intracellular redox status. Based on these observations, we propose to use ROS concentration averaged over the cell volume instead of ROS level as a measure of intracellular redox balance. We show that attempts to use ROS level for comparative analysis of redox status of morphologically different cells could lead to false conclusions. Methods for the assessment of ROS concentration based on flow cytometry analysis with the use of H 2 DCFDA dye and HyPer, genetically encoded probe for hydrogen peroxide, are discussed. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Cryo-survival, fertilization and early embryonic development of vitrified oocytes derived from mice of different reproductive age

PubMed Central

Yan, Jie; Suzuki, Joao; Yu, Xiaomin; Kan, Frederick W. K.

2010-01-01

Purpose To evaluate the effect of female reproductive age on oocyte cryo-survival, fertilization and the subsequent embryonic development following vitrification using the mouse model in order to address the question of how maternal reproductive age is related to fertility preservation. Methods Oocytes were collected from mice of different reproductive age: (1) 8–10 weeks, (2) 16–20 weeks, (3) 32–36 weeks, and (4) 44–48 weeks. Following vitrification and warming, the oocytes in each group were assessed for cryo-survival, fertilization and embryonic development as well as for the quality of blastocysts. Fresh oocytes without undergoing vitrification were used in each age group as controls. Results The mean number of oocytes retrieved following superovulation was found to reduce significantly (P < 0.05) in mice from 32–36 weeks of age (18.1 ± 8.5) compared with 8–10 weeks of age (26.8 ± 9.8) and 16–20 weeks of age (23.9 ± 4.2) respectively. The cryo-survival rate of oocytes was reduced significantly (P < 0.05) in mice of 44–48 weeks of age (90.4% ± 7.9) compared with the other 3 groups (98.8% ± 2.1, 98.0% ± 3.3 and 98.5% ± 2.2, respectively). The cleavage rate of vitrified oocytes declined significantly following the increase in maternal age in mice of 32–36 weeks of age (69.7% ± 20.8) forward (63.6% ± 9.2). However, no significant difference in the cleavage rate was found among the control groups of different maternal ages. The rate of embryo development to the blastocyst stage in the vitrified oocytes also significantly declined following the increase in maternal age (71.8% ± 8.8, 66.4% ± 10.7, 64.2% ± 17.4 and 4.1% ± 8.3 respectively). There were no such differences in the rates of embryo development to the blastocyst stage among the control groups following the increase in maternal age (75.9% ± 12.2, 79.5% ± 28.9, 70.2% ± 17.4 and 69.3% ± 19.0 respectively). However, the quality of blastocysts produced from 32–36 weeks and 44–48 weeks of ages was significantly poor in term of total cell numbers and the ratio of inner cell mass(ICM) / trophectoderm (TE) compared to younger age in both vitrified and control groups Conclusions Cryo-survival of oocytes following vitrification and warming procedures is associated with female reproductive age. There is a more negative impact on the oocytes following vitrification and warming with the increase of maternal age. PMID:20640502

Induced Wnt5a expression perturbs embryonic outgrowth and intestinal elongation, but is well-tolerated in adult mice.

PubMed

Bakker, Elvira R M; Raghoebir, Lalini; Franken, Patrick F; Helvensteijn, Werner; van Gurp, Léon; Meijlink, Frits; van der Valk, Martin A; Rottier, Robbert J; Kuipers, Ernst J; van Veelen, Wendy; Smits, Ron

2012-09-01

Wnt5a is essential during embryonic development, as indicated by mouse Wnt5a knockout embryos displaying outgrowth defects of multiple structures including the gut. The dynamics of Wnt5a involvement in these processes is unclear, and perinatal lethality of Wnt5a knockout embryos has hampered investigation of Wnt5a during postnatal stages in vivo. Although in vitro studies have suggested a relevant role for Wnt5a postnatally, solid evidence for a significant impact of Wnt5a within the complexity of an adult organism is lacking. We generated a tightly-regulated inducible Wnt5a transgenic mouse model and investigated the effects of Wnt5a induction during different time-frames of embryonic development and in adult mice, focusing on the gastrointestinal tract. When induced in embryos from 10.5 dpc onwards, Wnt5a expression led to severe outgrowth defects affecting the gastrointestinal tracts, limbs, facial structures and tails, closely resembling the defects observed in Wnt5a knockout mice. However, Wnt5a induction from 13.5 dpc onwards did not cause this phenotype, indicating that the most critical period for Wnt5a in embryonic development is prior to 13.5 dpc. In adult mice, induced Wnt5a expression did not reveal abnormalities, providing the first in vivo evidence that Wnt5a has no major impact on mouse intestinal homeostasis postnatally. Protein expression of Wnt5a receptor Ror2 was strongly reduced in adult intestine compared to embryonic stages. Moreover, we uncovered a regulatory process where induction of Wnt5a causes downregulation of its receptor Ror2. Taken together, our results indicate a role for Wnt5a during a restricted time-frame of embryonic development, but suggest no impact during homeostatic postnatal stages. Copyright © 2012 Elsevier Inc. All rights reserved.

Forkhead box transcription factors in embryonic heart development and congenital heart disease.

PubMed

Zhu, Hong

2016-01-01

Embryonic heart development is a very complicated process regulated precisely by a network composed of many genes and signaling pathways in time and space. Forkhead box (Fox, FOX) proteins are a family of transcription factors characterized by the presence of an evolutionary conserved "forkhead"or "winged-helix" DNA-binding domain and able to organize temporal and spatial gene expression during development. They are involved in a wide variety of cellular processes, such as cell cycle progression, proliferation, differentiation, migration, metabolism and DNA damage response. An abundance of studies in model organisms and systems has established that Foxa2, Foxc1/c2, Foxh1 and Foxm1, Foxos and Foxps are important components of the signaling pathways that instruct cardiogenesis and embryonic heart development, playing paramount roles in heart development. The previous studies also have demonstrated that mutations in some of the forkhead box genes and the aberrant expression of forkhead box gene are heavily implicated in the congenital heart disease (CHD) of humans. This review primarily focuses on the current understanding of heart development regulated by forkhead box transcription factors and molecular genetic mechanisms by which forkhead box factors modulate heart development during embryogenesis and organogenesis. This review also summarizes human CHD related mutations in forkhead box genes as well as the abnormal expression of forkhead box gene, and discusses additional possible regulatory mechanisms of the forkhead box genes during embryonic heart development that warrant further investigation. Copyright © 2015 Elsevier Inc. All rights reserved.

The effects of triclosan on pluripotency factors and development of mouse embryonic stem cells and zebrafish.

PubMed

Chen, Xiaojiao; Xu, Bo; Han, Xiumei; Mao, Zhilei; Chen, Minjian; Du, Guizhen; Talbot, Prue; Wang, Xinru; Xia, Yankai

2015-04-01

Triclosan (TCS) poses potential risks to reproduction and development due to its endocrine-disrupting properties. However, the mechanism of TCS's effects on early embryonic development is little known. Embryonic stem cells (ESC) and zebrafish embryos provide valuable models for testing the toxic effects of environmental chemicals on early embryogenesis. In this study, mouse embryonic stem cells (mESC) were acutely exposed to TCS for 24 h, and general cytotoxicity and the effect of TCS on pluripotency were then evaluated. In addition, zebrafish embryos were exposed to TCS from 2- to 24-h post-fertilization (hpf), and their morphology was evaluated. In mESC, alkaline phosphatase staining was significantly decreased after treatment with the highest concentration of TCS (50 μM). Although the expression levels of Sox2 mRNA were not changed, the mRNA levels of Oct4 and Nanog in TCS-treated groups were significantly decreased compared to controls. In addition, the protein levels of Oct4, Sox2 and Nanog were significantly reduced in response to TCS treatment. MicroRNA (miR)-134, an expression inhibitor of pluripotency markers, was significantly increased in TCS-treated mESC. In zebrafish experiments, after 24 hpf of treatment, the controls had developed to the late stage of somitogenesis, while embryos exposed to 300 μg/L of TCS were still at the early stage of somitogenesis, and three genes (Oct4, Sox2 and Nanog) were upregulated in treated groups when compared with the controls. The two models demonstrated that TCS may affect early embryonic development by disturbing the expression of the pluripotency markers (Oct4, Sox2 and Nanog).

Bone matrix calcification during embryonic and postembryonic rat calvarial development assessed by SEM-EDX spectroscopy, XRD, and FTIR spectroscopy.

PubMed

Henmi, Akiko; Okata, Hiroshi; Anada, Takahisa; Yoshinari, Mariko; Mikami, Yasuto; Suzuki, Osamu; Sasano, Yasuyuki

2016-01-01

Bone mineral is constituted of biological hydroxyapatite crystals. In developing bone, the mineral crystal matures and the Ca/P ratio increases. However, how an increase in the Ca/P ratio is involved in maturation of the crystal is not known. The relationships among organic components and mineral changes are also unclear. The study was designed to investigate the process of calcification during rat calvarial bone development. Calcification was evaluated by analyzing the atomic distribution and concentration of Ca, P, and C with scanning electron microscopy (SEM)-energy-dispersive X-ray (EDX) spectroscopy and changes in the crystal structure with X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Histological analysis showed that rat calvarial bone formation started around embryonic day 16. The areas of Ca and P expanded, matching the region of the developing bone matrix, whereas the area of C became localized around bone. X-ray diffraction and FTIR analysis showed that the amorphous-like structure of the minerals at embryonic day 16 gradually transformed into poorly crystalline hydroxyapatite, whereas the proportion of mineral to protein increased until postnatal week 6. FTIR analysis also showed that crystallization of hydroxyapatite started around embryonic day 20, by which time SEM-EDX spectroscopy showed that the Ca/P ratio had increased and the C/Ca and C/P ratios had decreased significantly. The study suggests that the Ca/P molar ratio increases and the proportion of organic components such as proteins of the bone matrix decreases during the early stage of calcification, whereas crystal maturation continues throughout embryonic and postembryonic bone development.

Comparative analysis of miRNA expression during the development of insects of different metamorphosis modes and germ-band types.

PubMed

Ylla, Guillem; Piulachs, Maria-Dolors; Belles, Xavier

2017-10-11

Do miRNAs contribute to specify the germ-band type and the body structure in the insect embryo? Our goal was to address that issue by studying the changes in miRNA expression along the ontogeny of the German cockroach Blattella germanica, which is a short germ-band and hemimetabolan species. We sequenced small RNA libraries representing 11 developmental stages of B. germanica ontogeny (with especial emphasis on embryogenesis) and the changes in miRNA expression were examined. Data were compared with equivalent data for two long germ-band holometabolan species Drosophila melanogaster and Drosophila virilis, and the short germ-band holometabolan species Tribolium castaneum. The identification of B. germanica embryo small RNA sequences unveiled miRNAs not detected in previous studies, such as those of the MIR-309 family and 54 novel miRNAs. Four main waves of miRNA expression were recognized (with most miRNA changes occurring during the embryonic stages): the first from day 0 to day 1 of embryogenesis, the second during mid-embryogenesis (days 0-6), the third (with an acute expression peak) on day 2 of embryonic development, and the fourth during post-embryonic development. The second wave defined the boundaries of maternal-to-zygotic transition, with maternal mRNAs being cleared, presumably by Mir-309 and associated scavenger miRNAs. miRNAs follow well-defined patterns of expression over hemimetabolan ontogeny, patterns that are more diverse during embryonic development than during the nymphal stages. The results suggest that miRNAs play important roles in the developmental transitions between the embryonic stages of development (starting with maternal loading), during which they might influence the germ-band type and metamorphosis mode.

Distributional shift of urea production site from the extraembryonic yolk sac membrane to the embryonic liver during the development of cloudy catshark (Scyliorhinus torazame).

PubMed

Takagi, Wataru; Kajimura, Makiko; Tanaka, Hironori; Hasegawa, Kumi; Ogawa, Shuntaro; Hyodo, Susumu

2017-09-01

Urea is an essential osmolyte for marine cartilaginous fishes. Adult elasmobranchs and holocephalans are known to actively produce urea in the liver, muscle and other extrahepatic organs; however, osmoregulatory mechanisms in the developing cartilaginous fish embryo with an undeveloped urea-producing organ are poorly understood. We recently described the contribution of extraembryonic yolk sac membranes (YSM) to embryonic urea synthesis during the early developmental period of the oviparous holocephalan elephant fish (Callorhinchus milii). In the present study, to test whether urea production in the YSM is a general phenomenon among oviparous Chondrichthyes, we investigated gene expression and activities of ornithine urea cycle (OUC) enzymes together with urea concentrations in embryos of the elasmobranch cloudy catshark (Scyliorhinus torazame). The intracapsular fluid, in which the catshark embryo develops, had a similar osmolality to seawater, and embryos maintained a high concentration of urea at levels similar to that of adult plasma throughout development. Relative mRNA expressions and activities of catshark OUC enzymes were significantly higher in YSM than in embryos until stage 32. Concomitant with the development of the embryonic liver, the expression levels and activities of OUC enzymes were markedly increased in the embryo from stage 33, while those of the YSM decreased from stage 32. The present study provides further evidence that the YSM contributes to embryonic urea homeostasis until the liver and other extrahepatic organs become fully functional, and that urea-producing tissue shifts from the YSM to the embryonic liver in the late developmental period of oviparous marine cartilaginous fishes. Copyright © 2017 Elsevier Inc. All rights reserved.

Redeployment of germ layers related TFs shows regionalized expression during two non-embryonic developments.

PubMed

Ricci, Lorenzo; Cabrera, Fabien; Lotito, Sonia; Tiozzo, Stefano

2016-08-01

In all non-vertebrate metazoan phyla, species that evolved non-embryonic developmental pathways as means of propagation or regeneration can be found. In this context, new bodies arise through asexual reproduction processes (such as budding) or whole body regeneration, that lack the familiar temporal and spatial cues classically associated with embryogenesis, like maternal determinants, or gastrulation. The molecular mechanisms underlying those non-embryonic developments (i.e., regeneration and asexual reproduction), and their relationship to those deployed during embryogenesis are poorly understood. We have addressed this question in the colonial ascidian Botryllus schlosseri, which undergoes an asexual reproductive process via palleal budding (PB), as well as a whole body regeneration by vascular budding (VB). We identified early regenerative structures during VB and then followed the fate of differentiating tissues during both non-embryonic developments (PB and VB) by monitoring the expression of genes known to play key functions in germ layer specification with well conserved expression patterns in solitary ascidian embryogenesis. The expression patterns of FoxA1, GATAa, GATAb, Otx, Bra, Gsc and Tbx2/3 were analysed during both PB and VB. We found that the majority of these transcription factors were expressed during both non-embryonic developmental processes, revealing a regionalization of the palleal and vascular buds. Knockdown of GATAa by siRNA in palleal buds confirmed that preventing the correct development of one of these regions blocks further tissue specification. Our results indicate that during both normal and injury-induced budding, a similar alternative developmental program operates via early commitment of epithelial regions. Copyright © 2016. Published by Elsevier Inc.

Embryonic exposure to model naphthenic acids delays growth and hatching in the pond snail Lymnaea stagnalis.

PubMed

Johnston, Christina U; Clothier, Lindsay N; Quesnel, Dean M; Gieg, Lisa M; Chua, Gordon; Hermann, Petra M; Wildering, Willem C

2017-02-01

Naphthenic acids (NAs), a class of structurally diverse carboxylic acids with often complex ring structures and large aliphatic tail groups, are important by-products of many petrochemical processes including the oil sands mining activity of Northern Alberta. While it is evident that NAs have both acute and chronic harmful effects on many organisms, many aspects of their toxicity remain to be clarified. Particularly, while substantive data sets have been collected on NA toxicity in aquatic prokaryote and vertebrate model systems, to date, nothing is known about the toxic effects of these compounds on the embryonic development of aquatic invertebrate taxa, including freshwater mollusks. This study examines under laboratory conditions the toxicity of NAs extracted from oil sands process water (OSPW) and the low-molecular weight model NAs cyclohexylsuccinic acid (CHSA), cyclohexanebutyric acid (CHBA), and 4-tert-butylcyclohexane carboxylic acid (4-TBCA) on embryonic development of the snail Lymnaea stagnalis, a common freshwater gastropod with a broad Palearctic distribution. Evidence is provided for concentration-dependent teratogenic effects of both OSPW-derived and model NAs with remarkably similar nominal threshold concentrations between 15 and 20 mg/L and 28d EC 50 of 31 mg/L. In addition, the data provide evidence for substantial toxicokinetic differences between CHSA, CHBA and 4-TBCA. Together, our study introduces Lymnaea stagnalis embryonic development as an effective model to assay NA-toxicity and identifies molecular architecture as a potentially important toxicokinetic parameter in the toxicity of low-molecular weight NA in embryonic development of aquatic gastropods. Copyright © 2016 Elsevier Ltd. All rights reserved.

Engineering human cell spheroids to model embryonic tissue fusion in vitro

PubMed Central

Wolf, Cynthia J.; Wood, Carmen; Ren, Hongzu; Grindstaff, Rachel; Padgett, William; Swank, Adam; MacMillan, Denise; Fisher, Anna; Winnik, Witold; Abbott, Barbara D.

2017-01-01

Epithelial-mesenchymal interactions drive embryonic fusion events during development, and perturbations of these interactions can result in birth defects. Cleft palate and neural tube defects can result from genetic defects or environmental exposures during development, yet very little is known about the effect of chemical exposures on fusion events during human development because of a lack of relevant and robust human in vitro assays of developmental fusion behavior. Given the etiology and prevalence of cleft palate and the relatively simple architecture and composition of the embryonic palate, we sought to develop a three-dimensional culture system that mimics the embryonic palate and could be used to study fusion behavior in vitro using human cells. We engineered size-controlled human Wharton’s Jelly stromal cell (HWJSC) spheroids and established that 7 days of culture in osteogenesis differentiation medium was sufficient to promote an osteogenic phenotype consistent with embryonic palatal mesenchyme. HWJSC spheroids supported the attachment of human epidermal keratinocyte progenitor cells (HPEKp) on the outer spheroid surface likely through deposition of collagens I and IV, fibronectin, and laminin by mesenchymal spheroids. HWJSC spheroids coated in HPEKp cells exhibited fusion behavior in culture, as indicated by the removal of epithelial cells from the seams between spheroids, that was dependent on epidermal growth factor signaling and fibroblast growth factor signaling in agreement with palate fusion literature. The method described here may broadly apply to the generation of three-dimensional epithelial-mesenchymal co-cultures to study developmental fusion events in a format that is amenable to predictive toxicology applications. PMID:28898253

Intermolecular Interactions of Homologs of Germ Plasm Components in Mammalian Germ Cells

PubMed Central

Fox, Mark S.; Clark, Amander T.; El Majdoubi, Mohammed; Vigne, Jean-Louis; Urano, Jun; Hostetler, Chris E.; Griswold, Michael D.; Weiner, Richard I.; Pera, Renee A. Reijo

2007-01-01

In some species such as flies, worms, frogs, and fish the key to forming and maintaining early germ cell populations is the assembly of germ plasm, microscopically-distinct egg cytoplasm that is rich in RNAs, RNA-binding proteins and ribosomes. Cells which inherit germ plasm are destined for the germ cell lineage. In contrast, in mammals, germ cells are formed and maintained later in development as a result of inductive signaling from one embryonic cell type to another. Research advances, using complementary approaches, including identification of key signaling factors that act during the initial stages of germ cell development, differentiation of germ cells in vitro from mouse and human embryonic stem cells and the demonstration, that homologs of germ plasm components are conserved in mammals, have shed light on key elements in the early development of mammalian germ cells. Here, we use FRET (Fluorescence Resonance Energy Transfer) to demonstrate that living mammalian germ cells possess specific RNA/protein complexes that contain germ plasm homologs, beginning in the earliest stages of development examined. Moreover, we demonstrate that although both human and mouse germ cells and embryonic stem cells express the same proteins, germ cell specific protein/protein interactions distinguish germ cells from precursor embryonic stem cells in vitro; interactions also determine sub-cellular localization of complex components. Finally, we suggest that assembly of similar protein complexes may be central to differentiation of diverse cell lineages and provide useful diagnostic tools for isolation of specific cell types from the assorted types differentiated from embryonic stem cells. PMID:16996493

Rhabdomyosarcoma of the lower female genital tract: an analysis of 144 cases.

PubMed

Nasioudis, Dimitrios; Alevizakos, Michail; Chapman-Davis, Eloise; Witkin, Steven S; Holcomb, Kevin

2017-08-01

The aim of the present study was to elucidate the clinico-pathological characteristics of female patients with lower genital tract rhabdomyosarcoma (RMS) stratified by age group and investigate their prognosis, using a multi-institutional database. The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database was accessed (1973-2013) and a cohort of females diagnosed with RMS of the lower genital tract (vulva, vagina, cervix) was drawn. Five-year overall survival (OS) rate was estimated following generation of Kaplan-Meier curves and compared with the log-rank test. A total of 144 eligible cases were identified; 51.4 and 48.6% originated from the vagina/vulva and the cervix, respectively. Median patient age was 16 years and distant metastases were rare (ten cases). The majority of tumors were of embryonal histology (75.7%). Non-embryonal RMS was more prevalent in the older patient groups. Tumors originating from the cervix were more common among adolescents and premenopausal women. Rate of LN involvement was 52.9 and 20% for vulvovaginal and cervical tumors (p = 0.02). Five-year OS rate was 68.4%; factors associated with better OS were younger age, absence of distant metastasis, embryonal histology, negative LNs, and performance of surgery. For prepubertal girls and adolescents, radical surgery did not confer a survival benefit compared to local tumor excision. RMS of the lower genital tract primarily affects prepubertal girls and adolescents, who have excellent survival rates; however, outcomes for adults remain poor.

Transcriptional role of androgen receptor in the expression of long non-coding RNA Sox2OT in neurogenesis

PubMed Central

Tosetti, Valentina; Sassone, Jenny; Ferri, Anna L. M.; Taiana, Michela; Bedini, Gloria; Nava, Sara; Brenna, Greta; Di Resta, Chiara; Pareyson, Davide; Di Giulio, Anna Maria; Carelli, Stephana

2017-01-01

The complex architecture of adult brain derives from tightly regulated migration and differentiation of precursor cells generated during embryonic neurogenesis. Changes at transcriptional level of genes that regulate migration and differentiation may lead to neurodevelopmental disorders. Androgen receptor (AR) is a transcription factor that is already expressed during early embryonic days. However, AR role in the regulation of gene expression at early embryonic stage is yet to be determinate. Long non-coding RNA (lncRNA) Sox2 overlapping transcript (Sox2OT) plays a crucial role in gene expression control during development but its transcriptional regulation is still to be clearly defined. Here, using Bicalutamide in order to pharmacologically inactivated AR, we investigated whether AR participates in the regulation of the transcription of the lncRNASox2OTat early embryonic stage. We identified a new DNA binding region upstream of Sox2 locus containing three androgen response elements (ARE), and found that AR binds such a sequence in embryonic neural stem cells and in mouse embryonic brain. Our data suggest that through this binding, AR can promote the RNA polymerase II dependent transcription of Sox2OT. Our findings also suggest that AR participates in embryonic neurogenesis through transcriptional control of the long non-coding RNA Sox2OT. PMID:28704421

Transcriptional role of androgen receptor in the expression of long non-coding RNA Sox2OT in neurogenesis.

PubMed

Tosetti, Valentina; Sassone, Jenny; Ferri, Anna L M; Taiana, Michela; Bedini, Gloria; Nava, Sara; Brenna, Greta; Di Resta, Chiara; Pareyson, Davide; Di Giulio, Anna Maria; Carelli, Stephana; Parati, Eugenio A; Gorio, Alfredo

2017-01-01

The complex architecture of adult brain derives from tightly regulated migration and differentiation of precursor cells generated during embryonic neurogenesis. Changes at transcriptional level of genes that regulate migration and differentiation may lead to neurodevelopmental disorders. Androgen receptor (AR) is a transcription factor that is already expressed during early embryonic days. However, AR role in the regulation of gene expression at early embryonic stage is yet to be determinate. Long non-coding RNA (lncRNA) Sox2 overlapping transcript (Sox2OT) plays a crucial role in gene expression control during development but its transcriptional regulation is still to be clearly defined. Here, using Bicalutamide in order to pharmacologically inactivated AR, we investigated whether AR participates in the regulation of the transcription of the lncRNASox2OTat early embryonic stage. We identified a new DNA binding region upstream of Sox2 locus containing three androgen response elements (ARE), and found that AR binds such a sequence in embryonic neural stem cells and in mouse embryonic brain. Our data suggest that through this binding, AR can promote the RNA polymerase II dependent transcription of Sox2OT. Our findings also suggest that AR participates in embryonic neurogenesis through transcriptional control of the long non-coding RNA Sox2OT.

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.

The effect of excess expression of GFP in a novel heart-specific green fluorescence zebrafish regulated by nppa enhancer at early embryonic development.

PubMed

Huang, Wen; Deng, Yun; Dong, Wei; Yuan, Wuzhou; Wan, Yongqi; Mo, Xiaoyan; Li, Yongqing; Wang, Zequn; Wang, Yuequn; Ocorr, Karen; Zhang, Bo; Lin, Shuo; Wu, Xiushan

2011-02-01

In order to study the impalpable effect of GFP in homozygous heart-specific GFP-positive zebrafish during the early stage, the researchers analyzed the heart function of morphology and physiology at the first 3 days after fertilization. This zebrafish line was produced by a large-scale Tol2 transposon mediated enhancer trap screen that generated a transgenic zebrafish with a heart-specific expression of green fluorescent protein (GFP)-tagged under control of the nppa enhancer. In situ hybridization experiments showed that the nppa:GFP line faithfully recapitulated both the spatial and temporal expressions of the endogenous nppa. Green fluorescence was intensively and specifically expressed in the myocardial cells located both in the heart chambers and in the atrioventricular canal. The embryonic heart of nppa:GFP line developed normally compared with those in the wild type. There was no difference between the nappa:GFP and wild type lines with respect to heart rate, overall size, ejection volume, and fractional shortening. Thus the excess expression of GFP in this transgenic line seemed to exert no detrimental effects on zebrafish hearts during the early stages.

Clinicopathologic assessment of pancreatic ductal carcinoma located at the head of the pancreas, in relation to embryonic development.

PubMed

Okamura, Yukiyasu; Fujii, Tsutomu; Kanzaki, Akiyuki; Yamada, Suguru; Sugimoto, Hiroyuki; Nomoto, Shuji; Takeda, Shin; Nakao, Akimasa

2012-05-01

Pancreaticoduodenectomy is performed for pancreatic head cancer that originated from the dorsal or ventral primordium. Although the extent of lymph node (LN) dissection is the same irrespective of the origin, the lymphatic continuities may differ between the 2 primordia. Between March 2003 and September 2010, 152 patients underwent pancreaticoduodenectomy for pancreatic cancer. One hundred six patients were assigned into 2 groups according to tumor location on preoperative computed tomography, and their clinical and pathological features were retrospectively analyzed in view of the embryonic development of the pancreas. Sixty of 106 patients were classified with tumors that were derived from the dorsal pancreas (D group) and 46 from the ventral pancreas (V group). The frequency of LN involvement around the middle colic artery (LN 15) in the D group was higher than in the V group (P = 0.008). The rate of additional resection of the pancreas tended to be higher in the D group (P = 0.067). The present study showed the detailed pattern of spread of pancreatic ductal carcinoma to the LNs and provided important information for determining the optimal surgical strategy.