Ultrastructural changes and the distribution of arabinogalactan proteins during somatic embryogenesis of banana (Musa spp. AAA cv. 'Yueyoukang 1').

PubMed

Pan, Xiao; Yang, Xiao; Lin, Guimei; Zou, Ru; Chen, Houbin; Samaj, Jozef; Xu, Chunxiang

2011-08-01

A better understanding of somatic embryogenesis in banana (Musa spp.) may provide a practical way to improve regeneration of banana plants. In this study, we applied scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to visualize the ultrastructural changes during somatic embryogenesis of banana (Musa AAA cv. 'Yueyoukang 1'). We also used histological and immunohistochemical techniques with 16 monoclonal antibodies to study the spatial distribution and cellular/subcellular localization of different arabinogalactan protein (AGP) components of the cell wall during somatic embryogenesis. Histological study with periodic acid-Schiff staining documented diverse embryogenic stages from embryogenic cells (ECs) to the late embryos. SEM revealed a mesh-like structure on the surface of proembryos which represented an early structural marker of somatic embryogenesis. TEM showed that ECs were rich in juvenile mitochondria, endoplasmic reticulum and Golgi stacks. Cells in proembryos and early globular embryos resembled ECs, but they were more vacuolated, showed more regular nuclei and slightly more developed organelles. Immunocytochemical study revealed that the signal of most AGP epitopes was stronger in starch-rich cells when compared with typical ECs. The main AGP component in the extracellular matrix surface network of banana proembryos was the MAC204 epitope. Later, AGP immunolabelling patterns varied with the developmental stages of the embryos. These results about developmental regulation of AGP epitopes along with developmental changes in the ultrastructure of cells are providing new insights into the somatic embryogenesis of banana. Copyright © Physiologia Plantarum 2011.

Some ethylene biosynthesis and AP2/ERF genes reveal a specific pattern of expression during somatic embryogenesis in Hevea brasiliensis

PubMed Central

2012-01-01

Background Ethylene production and signalling play an important role in somatic embryogenesis, especially for species that are recalcitrant in in vitro culture. The AP2/ERF superfamily has been identified and classified in Hevea brasiliensis. This superfamily includes the ERFs involved in response to ethylene. The relative transcript abundance of ethylene biosynthesis genes and of AP2/ERF genes was analysed during somatic embryogenesis for callus lines with different regeneration potential, in order to identify genes regulated during that process. Results The analysis of relative transcript abundance was carried out by real-time RT-PCR for 142 genes. The transcripts of ERFs from group I, VII and VIII were abundant at all stages of the somatic embryogenesis process. Forty genetic expression markers for callus regeneration capacity were identified. Fourteen markers were found for proliferating calli and 35 markers for calli at the end of the embryogenesis induction phase. Sixteen markers discriminated between normal and abnormal embryos and, lastly, there were 36 markers of conversion into plantlets. A phylogenetic analysis comparing the sequences of the AP2 domains of Hevea and Arabidopsis genes enabled us to predict the function of 13 expression marker genes. Conclusions This first characterization of the AP2/ERF superfamily in Hevea revealed dramatic regulation of the expression of AP2/ERF genes during the somatic embryogenesis process. The gene expression markers of proliferating callus capacity to regenerate plants by somatic embryogenesis should make it possible to predict callus lines suitable to be used for multiplication. Further functional characterization of these markers opens up prospects for discovering specific AP2/ERF functions in the Hevea species for which somatic embryogenesis is difficult. PMID:23268714

Cellular and molecular changes associated with somatic embryogenesis induction in Agave tequilana.

PubMed

Portillo, L; Olmedilla, A; Santacruz-Ruvalcaba, F

2012-10-01

In spite of the importance of somatic embryogenesis for basic research in plant embryology as well as for crop improvement and plant propagation, it is still unclear which mechanisms and cell signals are involved in acquiring embryogenic competence by a somatic cell. The aim of this work was to study cellular and molecular changes involved in the induction stage in calli of Agave tequilana Weber cultivar azul in order to gain more information on the initial stages of somatic embryogenesis in this species. Cytochemical and immunocytochemical techniques were used to identify differences between embryogenic and non-embryogenic cells from several genotypes. Presence of granular structures was detected after somatic embryogenesis induction in embryogenic cells; composition of these structures as well as changes in protein and polysaccharide distribution was studied using Coomassie brilliant blue and Periodic Acid-Schiff stains. Distribution of arabinogalactan proteins (AGPs) and pectins was investigated in embryogenic and non-embryogenic cells by immunolabelling using anti-AGP monoclonal antibodies (JIM4, JIM8 and JIM13) as well as an anti-methyl-esterified pectin-antibody (JIM7), in order to evaluate major modifications in cell wall composition in the initial stages of somatic embryogenesis. Our observations pointed out that induction of somatic embryogenesis produced accumulation of proteins and polysaccharides in embryogenic cells. Presence of JIM8, JIM13 and JIM7 epitopes were detected exclusively in embryogenic cells, which supports the idea that specific changes in cell wall are involved in the acquisition of embryogenic competence of A. tequilana.

In-depth proteomics characterization of embryogenesis of the honey bee worker (Apis mellifera ligustica).

PubMed

Fang, Yu; Feng, Mao; Han, Bin; Lu, Xiaoshan; Ramadan, Haitham; Li, Jianke

2014-09-01

Identifying proteome changes of honey bee embryogenesis is of prime importance for unraveling the molecular mechanisms that they underlie. However, many proteomic changes during the embryonic period are not well characterized. We analyzed the proteomic alterations over the complete time course of honey bee worker embryogenesis at 24, 48, and 72 h of age, using mass spectrometry-based proteomics, label-free quantitation, and bioinformatics. Of the 1460 proteins identified the embryo of all three ages, the core proteome (proteins shared by the embryos of all three ages, accounting for 40%) was mainly involved in protein synthesis, metabolic energy, development, and molecular transporter, which indicates their centrality in driving embryogenesis. However, embryos at different developmental stages have their own specific proteome and pathway signatures to coordinate and modulate developmental events. The young embryos (<24 h) stronger expression of proteins related to nutrition storage and nucleic acid metabolism may correlate with the cell proliferation occurring at this stage. The middle aged embryos (24-48 h) enhanced expression of proteins associated with cell cycle control, transporters, antioxidant activity, and the cytoskeleton suggest their roles to support rudimentary organogenesis. Among these proteins, the biological pathways of aminoacyl-tRNA biosynthesis, β-alanine metabolism, and protein export are intensively activated in the embryos of middle age. The old embryos (48-72 h) elevated expression of proteins implicated in fatty acid metabolism and morphogenesis indicate their functionality for the formation and development of organs and dorsal closure, in which the biological pathways of fatty acid metabolism and RNA transport are highly activated. These findings add novel understanding to the molecular details of honey bee embryogenesis, in which the programmed activation of the proteome matches with the physiological transition observed during

In-depth Proteomics Characterization of Embryogenesis of the Honey Bee Worker (Apis mellifera ligustica) *

PubMed Central

Fang, Yu; Feng, Mao; Han, Bin; Lu, Xiaoshan; Ramadan, Haitham; Li, Jianke

2014-01-01

Identifying proteome changes of honey bee embryogenesis is of prime importance for unraveling the molecular mechanisms that they underlie. However, many proteomic changes during the embryonic period are not well characterized. We analyzed the proteomic alterations over the complete time course of honey bee worker embryogenesis at 24, 48, and 72 h of age, using mass spectrometry-based proteomics, label-free quantitation, and bioinformatics. Of the 1460 proteins identified the embryo of all three ages, the core proteome (proteins shared by the embryos of all three ages, accounting for 40%) was mainly involved in protein synthesis, metabolic energy, development, and molecular transporter, which indicates their centrality in driving embryogenesis. However, embryos at different developmental stages have their own specific proteome and pathway signatures to coordinate and modulate developmental events. The young embryos (<24 h) stronger expression of proteins related to nutrition storage and nucleic acid metabolism may correlate with the cell proliferation occurring at this stage. The middle aged embryos (24–48 h) enhanced expression of proteins associated with cell cycle control, transporters, antioxidant activity, and the cytoskeleton suggest their roles to support rudimentary organogenesis. Among these proteins, the biological pathways of aminoacyl-tRNA biosynthesis, β-alanine metabolism, and protein export are intensively activated in the embryos of middle age. The old embryos (48–72 h) elevated expression of proteins implicated in fatty acid metabolism and morphogenesis indicate their functionality for the formation and development of organs and dorsal closure, in which the biological pathways of fatty acid metabolism and RNA transport are highly activated. These findings add novel understanding to the molecular details of honey bee embryogenesis, in which the programmed activation of the proteome matches with the physiological transition observed during

Conservation of proteo-lipid nuclear membrane fusion machinery during early embryogenesis.

PubMed

Byrne, Richard D; Veeriah, Selvaraju; Applebee, Christopher J; Larijani, Banafshé

2014-01-01

The fusogenic lipid diacylglycerol is essential for remodeling gamete and zygote nuclear envelopes (NE) during early embryogenesis. It is unclear whether upstream signaling molecules are likewise conserved. Here we demonstrate PLCγ and its activator SFK1, which co-operate during male pronuclear envelope formation, also promote the subsequent male and female pronuclear fusion. PLCγ and SFK1 interact directly at the fusion site leading to PLCγ activation. This is accompanied by a spatially restricted reduction of PtdIns(4,5)P2. Consequently, pronuclear fusion is blocked by PLCγ or SFK1 inhibition. These findings identify new regulators of events in the early embryo and suggest a conserved "toolkit" of fusion machinery drives successive NE fusion events during embryogenesis.

Developmental Localization and Methylesterification of Pectin Epitopes during Somatic Embryogenesis of Banana (Musa spp. AAA)

PubMed Central

Xu, Chunxiang; Zhao, Lu; Pan, Xiao; Šamaj, Jozef

2011-01-01

Background The plant cell walls play an important role in somatic embryogenesis and plant development. Pectins are major chemical components of primary cell walls while homogalacturonan (HG) is the most abundant pectin polysaccharide. Developmental regulation of HG methyl-esterification degree is important for cell adhesion, division and expansion, and in general for proper organ and plant development. Methodology/Principal Findings Developmental localization of pectic homogalacturonan (HG) epitopes and the (1→4)-β-D-galactan epitope of rhamnogalacturonan I (RG-I) and degree of pectin methyl-esterification (DM) were studied during somatic embryogenesis of banana (Musa spp. AAA). Histological analysis documented all major developmental stages including embryogenic cells (ECs), pre-globular, globular, pear-shaped and cotyledonary somatic embryos. Histochemical staining of extracellularly secreted pectins with ruthenium red showed the most intense staining at the surface of pre-globular, globular and pear-shaped somatic embryos. Biochemical analysis revealed developmental regulation of galacturonic acid content and DM in diverse embryogenic stages. Immunodots and immunolabeling on tissue sections revealed developmental regulation of highly methyl-esterified HG epitopes recognized by JIM7 and LM20 antibodies during somatic embryogenesis. Cell walls of pre-globular/globular and late-stage embryos contained both low methyl-esterified HG epitopes as well as partially and highly methyl-esterified ones. Extracellular matrix which covered surface of early developing embryos contained pectin epitopes recognized by 2F4, LM18, JIM5, JIM7 and LM5 antibodies. De-esterification of cell wall pectins by NaOH caused a decrease or an elimination of immunolabeling in the case of highly methyl-esterified HG epitopes. However, immunolabeling of some low methyl-esterified epitopes appeared stronger after this base treatment. Conclusions/Significance These data suggest that both low

Identification of expressed sequences in the coffee genome potentially associated with somatic embryogenesis.

PubMed

Silva, A T; Paiva, L V; Andrade, A C; Barduche, D

2013-05-21

Brazil possesses the most modern and productive coffee growing farms in the world, but technological development is desired to cope with the increasing world demand. One way to increase Brazilian coffee growing productivity is wide scale production of clones with superior genotypes, which can be obtained with in vitro propagation technique, or from tissue culture. These procedures can generate thousands of clones. However, the methodologies for in vitro cultivation are genotype-dependent, which leads to an almost empirical development of specific protocols for each species. Therefore, molecular markers linked to the biochemical events of somatic embryogenesis would greatly facilitate the development of such protocols. In this context, sequences potentially involved in embryogenesis processes in the coffee plant were identified in silico from libraries generated by the Brazilian Coffee Genome Project. Through these in silico analyses, we identified 15 EST-contigs related to the embryogenesis process. Among these, 5 EST-contigs (3605, 9850, 13686, 17240, and 17265) could readily be associated with plant embryogenesis. Sequence analysis of EST-contig 3605, 9850, and 17265 revealed similarity to a polygalacturonase, to a cysteine-proteinase, and to an allergenine, respectively. Results also show that EST-contig 17265 sequences presented similarity to an expansin. Finally, analysis of EST-contig 17240 revealed similarity to a protein of unknown function, but it grouped in the similarity dendrogram with the WUSCHEL transcription factor. The data suggest that these EST-contigs are related to the embryogenic process and have potential as molecular markers to increase methodological efficiency in obtaining coffee plant embryogenic materials.

Differential Accumulation of Sunflower Tetraubiquitin mRNAs during Zygotic Embryogenesis and Developmental Regulation of Their Heat-Shock Response.

PubMed Central

Almoguera, C.; Coca, M. A.; Jordano, J.

1995-01-01

We have isolated and sequenced Ha UbiS, a cDNA for a dry-seed-stored mRNA that encodes tetraubiquitin. We have observed differential accumulation of tetraubiquitin mRNAs during sunflower (Helianthus annuus L.) zygotic embryogenesis. These mRNAs were up-regulated during late embryogenesis and reached higher prevalence in the dry seed, where they were found to be associated mainly with provascular tissue. UbiS mRNA, as confirmed by Rnase A protection experiments, accumulated also in response to heat shock, but only in leaves and later during postgerminative development. These novel observations demonstrate expression during seed maturation of specific plant polyubiquitin transcripts and developmental regulation of their heat-shock response. Using ubiquitin antibodies we also detected discrete, seed-specific proteins with distinct temporal expression patterns during zygotic embryogenesis. Some of these patterns were concurrent with UbiS mRNA accumulation in seeds. The most abundant ubiquitin-reacting proteins found in mature seeds were small (16-22 kD) and acidic (isoelectric points of 6.1-7.4). Possible functional implications for UbiS expression elicited from these observations are discussed. PMID:12228401

Hemoglobin promotes somatic embryogenesis in peanut cultures.

PubMed

Jayabalan, N; Anthony, P; Davey, M R; Power, J B; Lowe, K C

2004-02-01

Critical parameters influencing somatic embryogenesis include growth regulators and oxygen supply. Consequently, the present investigation has focused on optimization of a somatic embryogenic system for peanut (Arachis hypogaea L.) through media supplementation with the auxin, picloram. The latter at 30 mg L(-1) was optimal for inducing regeneration of somatic embryos from cultured explants of zygotic embryos. In contrast, somatic embryogenesis did not occur in the absence of this growth regulator. An assessment has also been made of the beneficial effect on somatic embryogenesis and plant regeneration of the commercial hemoglobin (Hb) solution, Erythrogen. Hemoglobin at 1:50 and 1:100 (v:v) stimulated increases in mean fresh weight (up to a maximum of 57% over control), mean number of explants producing somatic embryos (15%) and mean number of somatic embryos per explant (29%).

Pollen embryogenesis to induce, detect, and analyze mutants

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

Constantin, M.J.

The development of fully differentiated plants from individual pollen grains through a series of developmental phases that resemble embryogenesis beginning with the zygote was demonstrated during the mid-1960's. This technology opened the door to the use of haploid plants (sporophytes with the gametic number of chromosomes) for plant breeding and genetic studies, biochemical and metabolic studies, and the selection of mutations. Although pollen embryogenesis has been demonstrated successfully in numerous plant genera, the procedure cannot as yet be used routinely to generate large populations of plants for experiments. Practical results from use of the technology in genetic toxicology research tomore » detect mutations have failed to fully realize the theoretical potential; further developments of the technology could overcome the limitations. Pollen embryogenesis could be used to develop plants from mutant pollen grains to verify that genetic changes are involved. Through either spontaneous or induced chromosome doubling, these plants can be made homozygous and used to analyze genetically the mutants involved. The success of this approach will depend on the mutant frequency relative to the fraction of pollen grains that undergo embryogenesis; these two factors will dictate population size needed for success. Research effort is needed to further develop pollen embryogenesis for use in the detection of genotoxins under both laboratory and in situ conditions.« less

Unfertilized ovary: a novel explant for coconut (Cocos nucifera L.) somatic embryogenesis.

PubMed

Perera, Prasanthi I P; Hocher, Valerie; Verdeil, Jean Luc; Doulbeau, Sylvie; Yakandawala, Deepthi M D; Weerakoon, L Kaushalya

2007-01-01

Unfertilized ovaries isolated from immature female flowers of coconut (Cocos nucifera L.) were tested as a source of explants for callogenesis and somatic embryogenesis. The correct developmental stage of ovary explants and suitable in vitro culture conditions for consistent callus production were identified. The concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) and activated charcoal was found to be critical for callogenesis. When cultured in a medium containing 100 microM 2,4-D and 0.1% activated charcoal, ovary explants gave rise to 41% callusing. Embryogenic calli were sub-cultured into somatic embryogenesis induction medium containing 5 microM abscisic acid, followed by plant regeneration medium (with 5 microM 6-benzylaminopurine). Many of the somatic embryos formed were complete with shoot and root poles and upon germination they gave rise to normal shoots. However, some abnormal developments were also observed. Flow cytometric analysis revealed that all the calli tested were diploid. Through histological studies, it was possible to study the sequence of the events that take place during somatic embryogenesis including orientation, polarization and elongation of the embryos.

Setting the Clock for Fail-Safe Early Embryogenesis.

PubMed

Fickentscher, Rolf; Struntz, Philipp; Weiss, Matthias

2016-10-28

The embryogenesis of the small nematode Caenorhabditis elegans is a remarkably robust self-organization phenomenon. Cell migration trajectories in the early embryo, for example, are well explained by mechanical cues that push cells into positions where they experience the least repulsive forces. Yet, how this mechanically guided progress in development is properly timed has remained elusive so far. Here, we show that cell volumes and division times are strongly anticorrelated during the early embryogenesis of C. elegans with significant differences between somatic cells and precursors of the germline. Our experimental findings are explained by a simple model that in conjunction with mechanical guidance can account for the fail-safe early embryogenesis of C. elegans.

Somatic embryogenesis in cell cultures of Glycine species.

PubMed

Gamborg, O L; Davis, B P; Stahlhut, R W

1983-08-01

This report describes the development of procedures for the production of somatic embryos in cell cultures of Glycine species including soybean. The conditions for callus induction and initiation of rapidly growing cell suspension cultures were defined. Methods for inducing embryogenesis were tested on 16 lines of several Glycine species and cultivars of soybean. The SB-26 Culture of a G. soja gave the best results and was used in the experiments. Embryogenesis required the presence of picloram or 2,4-D. AMO 1618, CCC, PP-333 and Ancymidol enhanced the embryogenesis frequency. Plants of the G. soja (SB-26) were grown to maturity from seed-derived shoot tips. Characteristics of the plants are discussed.

Effects of biotic and abiotic factors on the oxygen content of green sea turtle nests during embryogenesis.

PubMed

Chen, Chiu-Lin; Wang, Chun-Chun; Cheng, I-Jiunn

2010-10-01

Several biotic and abiotic factors can influence nest oxygen content during embryogenesis. Several of these factors were determined during each developmental stage of green sea turtle embryos on Wan-an Island, Penghu Archipelago, Taiwan. We examined oxygen content in 7 nests in 2007 and 11 in 2008. Oxygen in the adjacent sand, total and viable clutch sizes, air, sand and nest temperatures, and sand characters of each nest were also determined. Oxygen content was lower in late stages than in the early and middle stages. It was also lower in the middle layer than in the upper and bottom layers. Nest temperature showed opposite trends, reaching its maximum value in late stages of development. Nest oxygen content was influenced by fraction of viable eggs, total clutch sizes, sand temperatures, maximum nest temperature and maximum change in the nest temperature during incubation. Clutch size during embryogenesis was the most influential factor overall. However, the major influential factors were different for different developmental stages. In the first half of the incubation, the development rate was low, and the change in the nest oxygen content was influenced mainly by the clutch size. During the second half, the rapid embryonic development rate became the dominant factor, and hatchling activities caused even greater oxygen consumption during the last stage of development.

Somatic embryogenesis, scanning electron microscopy, histology and biochemical analysis at different developing stages of embryogenesis in six date palm (Phoenix dactylifera L.) cultivars.

PubMed

Aslam, Junaid; Khan, Saeed Ahmad; Cheruth, Abdul Jaleel; Mujib, Abdul; Sharma, Maheshwar Pershad; Srivastava, Prem Shanker

2011-10-01

An efficient somatic embryogenesis system has been established in six date palm (Phoenix dactylifera L.) cultivars (Barhee, Zardai, Khalasah, Muzati, Shishi and Zart). Somatic embryogenesis (SE) was growth regulators and cultivars dependent. Friable embryogenic callus was induced from excised shoot tips on MS medium supplemented with various auxins particularly 2,4-dichlorophenoxyacetic acid (2,4-D, 1.5 mg 1(-l)). Suspension culture increased embryogenesis potentiality. Only a-naphthaleneacetic acid (NAA, 0.5 mg 1(-1)) produced somatic embryos in culture. Somatic embryos germinated and converted into plantlets in N(6)-benzyladenine (BAP, 0.75 mg 1(-l)) added medium following a treatment with thidiazuron (TDZ, 1.0 mg 1(-l)) for maturation. Scanning electron microscopy showed early stages of somatic embryo particularly, globular types, and was in masses. Different developing stages of embryogenesis (heart, torpedo and cotyledonary) were observed under histological preparation of embryogenic callus. Biochemical screening at various stages of somatic embryogenesis (embryogenic callus, somatic embryos, matured, germinated embryos and converted plantlets) of date palm cultivars has been conducted and discussed in detail. The result discussed in this paper indicates that somatic embryos were produced in numbers and converted plantlets can be used as a good source of alternative propagation. Genetic modification to the embryo precursor cell may improve the fruit quality and yield further.

Somatic embryogenesis, scanning electron microscopy, histology and biochemical analysis at different developing stages of embryogenesis in six date palm (Phoenix dactylifera L.) cultivars

PubMed Central

Aslam, Junaid; Khan, Saeed Ahmad; Cheruth, Abdul Jaleel; Mujib, Abdul; Sharma, Maheshwar Pershad; Srivastava, Prem Shanker

2011-01-01

An efficient somatic embryogenesis system has been established in six date palm (Phoenix dactylifera L.) cultivars (Barhee, Zardai, Khalasah, Muzati, Shishi and Zart). Somatic embryogenesis (SE) was growth regulators and cultivars dependent. Friable embryogenic callus was induced from excised shoot tips on MS medium supplemented with various auxins particularly 2,4-dichlorophenoxyacetic acid (2,4-D, 1.5 mg 1−l). Suspension culture increased embryogenesis potentiality. Only a-naphthaleneacetic acid (NAA, 0.5 mg 1−1) produced somatic embryos in culture. Somatic embryos germinated and converted into plantlets in N6-benzyladenine (BAP, 0.75 mg 1−l) added medium following a treatment with thidiazuron (TDZ, 1.0 mg 1−l) for maturation. Scanning electron microscopy showed early stages of somatic embryo particularly, globular types, and was in masses. Different developing stages of embryogenesis (heart, torpedo and cotyledonary) were observed under histological preparation of embryogenic callus. Biochemical screening at various stages of somatic embryogenesis (embryogenic callus, somatic embryos, matured, germinated embryos and converted plantlets) of date palm cultivars has been conducted and discussed in detail. The result discussed in this paper indicates that somatic embryos were produced in numbers and converted plantlets can be used as a good source of alternative propagation. Genetic modification to the embryo precursor cell may improve the fruit quality and yield further. PMID:23961149

MICROSPOROGENESIS AND EMBRYOGENESIS IN QUERCUS

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

Stairs, G. R.

1962-01-01

Representative species from two subgenera in the genus Quercus were examined for floral structure and phenology, microsporogenesis, and embryogenesis. The species selected for investigation were: Quercus alba in the Lepidobalanus subgenera, and Quercus coccinea and Quercus ilicifolia from the Erythrobalanus group. Photographs of flowering and photomicrographs of microsporogensis and embryogenesis are used for illustration. The male flowers of the three species are borne on catkins which develop in the scale leaf axils of the current vegetative bud or in separate male buds. Meiosis occurred in the spring at the beginning of bud enlargement; division figures were regular in all themore » material observed. A haploid chromosome number of 12 was confirmed for the three species. Pollen was shed on May 10, 1962, from trees of Quercus coccinea and Quercus ilicifolia; and on May 26, 1962 from Quercus alba. The female flowers are located in the axils of the new leaves. Seed development requires one growing season in Quercus alba, but two growing seasons are required to mature seed of Quercus coccinea and Quercus ilicifolia. The chronology of embryo development was similar for Quercus coccinea and Quercus ilicifolia; embryo development of Quercus alba was about two weeks behind that of the other two species. Definition of ovule dominance within a seed occurred at the time of early embryo development. Failure of this physiological expression of dominance results in multiseeded acorns. No abnormal embryogenesis per se was observed in relation to multiple embryo development. (auth)« less

LEAping to conclusions: a computational reanalysis of late embryogenesis abundant proteins and their possible roles.

PubMed

Wise, Michael J

2003-10-29

The late embryogenesis abundant (LEA) proteins cover a number of loosely related groups of proteins, originally found in plants but now being found in non-plant species. Their precise function is unknown, though considerable evidence suggests that LEA proteins are involved in desiccation resistance. Using a number of statistically-based bioinformatics tools the classification of a large set of LEA proteins, covering all Groups, is reexamined together with some previous findings. Searches based on peptide composition return proteins with similar composition to different LEA Groups; keyword clustering is then applied to reveal keywords and phrases suggestive of the Groups' properties. Previous research has suggested that glycine is characteristic of LEA proteins, but it is only highly over-represented in Groups 1 and 2, while alanine, thought characteristic of Group 2, is over-represented in Group 3, 4 and 6 but under-represented in Groups 1 and 2. However, for LEA Groups 1 2 and 3 it is shown that glutamine is very significantly over-represented, while cysteine, phenylalanine, isoleucine, leucine and tryptophan are significantly under-represented. There is also evidence that the Group 4 LEA proteins are more appropriately redistributed to Group 2 and Group 3. Similarly, Group 5 is better found among the Group 3 LEA proteins. There is evidence that Group 2 and Group 3 LEA proteins, though distinct, might be related. This relationship is also evident in the overlapping sets of keywords for the two Groups, emphasising alpha-helical structure and, at a larger scale, filaments, all of which fits well with experimental evidence that proteins from both Groups are natively unstructured, but become structured under stress conditions. The keywords support localisation of LEA proteins both in the nucleus and associated with the cytoskeleton, and a mode of action similar to chaperones, perhaps the cold shock chaperones, via a role in DNA-binding. In general, non-globular and

Spaceflight reduces somatic embryogenesis in orchardgrass (Poaceae)

NASA Technical Reports Server (NTRS)

Conger, B. V.; Tomaszewski, Z. Jr; McDaniel, J. K.; Vasilenko, A.

1998-01-01

Somatic embryos initiate and develop from single mesophyll cells in in vitro cultured leaf segments of orchard-grass (Dactylis glomerata L.). Segments were plated at time periods ranging from 21 to 0.9 d (21 h) prior to launch on an 11 d spaceflight (STS-64). Using a paired t-test, there was no significant difference in embryogenesis from preplating periods of 14 d and 21 d. However, embryogenesis was reduced by 70% in segments plated 21 h before launch and this treatment was significant at P=0.0001. The initial cell divisions leading to embryo formation would be taking place during flight in this treatment. A higher ratio of anticlinal:periclinal first cell divisions observed in the flight compared to the control tissue suggests that microgravity affects axis determination and embryo polarity at a very early stage. A similar reduction in zygotic embryogenesis would reduce seed formation and have important implications for long-term space flight or colonization where seeds would be needed either for direct consumption or to grow another generation of plants.

Identification and profiling of conserved and novel microRNAs involved in oil and oleic acid production during embryogenesis in Carya cathayensis Sarg.

PubMed

Wang, Zhengjia; Huang, Ruiming; Sun, Zhichao; Zhang, Tong; Huang, Jianqin

2017-05-01

MicroRNAs (miRNAs) are important regulators of plant development and fruit formation. Mature embryos of hickory (Carya cathayensis Sarg.) nuts contain more than 70% oil (comprising 90% unsaturated fatty acids), along with a substantial amount of oleic acid. To understand the roles of miRNAs involved in oil and oleic acid production during hickory embryogenesis, three small RNA libraries from different stages of embryogenesis were constructed. Deep sequencing of these three libraries identified 95 conserved miRNAs with 19 miRNA*s, 7 novel miRNAs (as well as their corresponding miRNA*s), and 26 potentially novel miRNAs. The analysis identified 15 miRNAs involved in oil and oleic acid production that are differentially expressed during embryogenesis in hickory. Among them, nine miRNA sequences, including eight conserved and one novel, were confirmed by qRT-PCR. In addition, 145 target genes of the novel miRNAs were predicted using a bioinformatic approach. Our results provide a framework for better understanding the roles of miRNAs during embryogenesis in hickory.

Drosophila embryogenesis scales uniformly across temperature in developmentally diverse species.

PubMed

Kuntz, Steven G; Eisen, Michael B

2014-04-01

Temperature affects both the timing and outcome of animal development, but the detailed effects of temperature on the progress of early development have been poorly characterized. To determine the impact of temperature on the order and timing of events during Drosophila melanogaster embryogenesis, we used time-lapse imaging to track the progress of embryos from shortly after egg laying through hatching at seven precisely maintained temperatures between 17.5 °C and 32.5 °C. We employed a combination of automated and manual annotation to determine when 36 milestones occurred in each embryo. D. melanogaster embryogenesis takes [Formula: see text]33 hours at 17.5 °C, and accelerates with increasing temperature to a low of 16 hours at 27.5 °C, above which embryogenesis slows slightly. Remarkably, while the total time of embryogenesis varies over two fold, the relative timing of events from cellularization through hatching is constant across temperatures. To further explore the relationship between temperature and embryogenesis, we expanded our analysis to cover ten additional Drosophila species of varying climatic origins. Six of these species, like D. melanogaster, are of tropical origin, and embryogenesis time at different temperatures was similar for them all. D. mojavensis, a sub-tropical fly, develops slower than the tropical species at lower temperatures, while D. virilis, a temperate fly, exhibits slower development at all temperatures. The alpine sister species D. persimilis and D. pseudoobscura develop as rapidly as tropical flies at cooler temperatures, but exhibit diminished acceleration above 22.5 °C and have drastically slowed development by 30 °C. Despite ranging from 13 hours for D. erecta at 30 °C to 46 hours for D. virilis at 17.5 °C, the relative timing of events from cellularization through hatching is constant across all species and temperatures examined here, suggesting the existence of a previously unrecognized timer controlling the

Embryogenesis and Larval Biology of the Cold-Water Coral Lophelia pertusa

PubMed Central

Strömberg, Susanna M.; Dahl, Mikael P.; Lundälv, Tomas; Brooke, Sandra

2014-01-01

Cold-water coral reefs form spectacular and highly diverse ecosystems in the deep sea but little is known about reproduction, and virtually nothing about the larval biology in these corals. This study is based on data from two locations of the North East Atlantic and documents the first observations of embryogenesis and larval development in Lophelia pertusa, the most common framework-building cold-water scleractinian. Embryos developed in a more or less organized radial cleavage pattern from ∼160 µm large neutral or negatively buoyant eggs, to 120–270 µm long ciliated planulae. Embryogenesis was slow with cleavage occurring at intervals of 6–8 hours up to the 64-cell stage. Genetically characterized larvae were sexually derived, with maternal and paternal alleles present. Larvae were active swimmers (0.5 mm s−1) initially residing in the upper part of the water column, with bottom probing behavior starting 3–5 weeks after fertilization. Nematocysts had developed by day 30, coinciding with peak bottom-probing behavior, and possibly an indication that larvae are fully competent to settle at this time. Planulae survived for eight weeks under laboratory conditions, and preliminary results indicate that these planulae are planktotrophic. The late onset of competency and larval longevity suggests a high dispersal potential. Understanding larval biology and behavior is of paramount importance for biophysical modeling of larval dispersal, which forms the basis for predictions of connectivity among populations. PMID:25028936

Study of model systems to test the potential function of Artemia group 1 late embryogenesis abundant (LEA) proteins.

PubMed

Warner, Alden H; Guo, Zhi-hao; Moshi, Sandra; Hudson, John W; Kozarova, Anna

2016-01-01

Embryos of the brine shrimp, Artemia franciscana, are genetically programmed to develop either ovoviparously or oviparously depending on environmental conditions. Shortly upon their release from the female, oviparous embryos enter diapause during which time they undergo major metabolic rate depression while simultaneously synthesize proteins that permit them to tolerate a wide range of stressful environmental events including prolonged periods of desiccation, freezing, and anoxia. Among the known stress-related proteins that accumulate in embryos entering diapause are the late embryogenesis abundant (LEA) proteins. This large group of intrinsically disordered proteins has been proposed to act as molecular shields or chaperones of macromolecules which are otherwise intolerant to harsh conditions associated with diapause. In this research, we used two model systems to study the potential function of the group 1 LEA proteins from Artemia. Expression of the Artemia group 1 gene (AfrLEA-1) in Escherichia coli inhibited growth in proportion to the number of 20-mer amino acid motifs expressed. As well, clones of E. coli, transformed with the AfrLEA-1 gene, expressed multiple bands of LEA proteins, either intrinsically or upon induction with isopropyl-β-thiogalactoside (IPTG), in a vector-specific manner. Expression of AfrLEA-1 in E. coli did not overcome the inhibitory effects of high concentrations of NaCl and KCl but modulated growth inhibition resulting from high concentrations of sorbitol in the growth medium. In contrast, expression of the AfrLEA-1 gene in Saccharomyces cerevisiae did not alter the growth kinetics or permit yeast to tolerate high concentrations of NaCl, KCl, or sorbitol. However, expression of AfrLEA-1 in yeast improved its tolerance to drying (desiccation) and freezing. Under our experimental conditions, both E. coli and S. cerevisiae appear to be potentially suitable hosts to study the function of Artemia group 1 LEA proteins under environmentally

Chemical Compositions, Somatic Embryogenesis, and Somaclonal Variation in Cumin

PubMed Central

Tohidfar, Masoud; Sadat Noori, Seyed Ahmad; Izadi Darbandi, Ali; Rao, Rosa

2017-01-01

This is the first report evaluating the relationship between the chemical compositions of cumin seeds (based on the analysis of the content of catalase, ascorbate peroxidase, proline, protein, terpenic compounds, alcohol/phenols, aldehydes, and epoxides) and the induction efficiency of somatic embryogenesis in two Iranian superior cumin landraces (Golestan and North Khorasan). Cotyledons isolated from Golestan landrace seeds cultivated on MS medium supplemented with 0.1 mg/L kinetin proved to be the best primary explant for the induction of somatic embryogenesis as well as the regeneration of the whole plantlet. Results indicated that different developmental stages of somatic embryos were simultaneously observed on a callus with embryogenic potential. The high content of catalase, ascorbate peroxidase, proline, and terpenic hydrocarbons and low content of alcoholic and phenolic compositions had a stimulatory effect on somatic embryogenesis. Band patterns of RAPD markers in regenerated plants were different from those of the mother plants. This may be related to somaclonal variations or pollination system of cumin. Generally, measurement of chemical compositions can be used as a marker for evaluating the occurrence of somatic embryogenesis in cumin. Also, somaclonal variations of regenerated plants can be applied by the plant breeders in breeding programs. PMID:29234682

Somatic Embryogenesis: Still a Relevant Technique in Citrus Improvement.

PubMed

Omar, Ahmad A; Dutt, Manjul; Gmitter, Frederick G; Grosser, Jude W

2016-01-01

The genus Citrus contains numerous fresh and processed fruit cultivars that are economically important worldwide. New cultivars are needed to battle industry threatening diseases and to create new marketing opportunities. Citrus improvement by conventional methods alone has many limitations that can be overcome by applications of emerging biotechnologies, generally requiring cell to plant regeneration. Many citrus genotypes are amenable to somatic embryogenesis, which became a key regeneration pathway in many experimental approaches to cultivar improvement. This chapter provides a brief history of plant somatic embryogenesis with focus on citrus, followed by a discussion of proven applications in biotechnology-facilitated citrus improvement techniques, such as somatic hybridization, somatic cybridization, genetic transformation, and the exploitation of somaclonal variation. Finally, two important new protocols that feature plant regeneration via somatic embryogenesis are provided: protoplast transformation and Agrobacterium-mediated transformation of embryogenic cell suspension cultures.

Comparative proteomic analysis of early somatic and zygotic embryogenesis in Theobroma cacao L.

PubMed

Noah, Alexandre Mboene; Niemenak, Nicolas; Sunderhaus, Stephanie; Haase, Christin; Omokolo, Denis Ndoumou; Winkelmann, Traud; Braun, Hans-Peter

2013-01-14

Somatic embryogenesis can efficiently foster the propagation of Theobroma cacao, but the poor quality of resulted plantlet hinders the use of this technique in the commercial scale. The current study has been initiated to systematically compare the physiological mechanisms underlying somatic and zygotic embryogenesis in T. cacao on the proteome level. About 1000 protein spots per fraction could be separated by two-dimensional isoelectric focusing/SDS PAGE. More than 50 of the protein spots clearly differed in abundance between zygotic and somatic embryos: 33 proteins spots were at least 3-fold higher in abundance in zygotic embryos and 20 in somatic embryos. Analyses of these protein spots differing in volume by mass spectrometry resulted in the identification of 68 distinct proteins. Many of the identified proteins are involved in genetic information processing (21 proteins), carbohydrate metabolism (11 proteins) and stress response (7 proteins). Somatic embryos especially displayed many stress related proteins, few enzymes involved in storage compound synthesis and an exceptional high abundance of endopeptidase inhibitors. Phosphoenolpyruvate carboxylase, which was accumulated more than 3-fold higher in zygotic embryos, represents a prominent enzyme in the storage compound metabolism in cacao seeds. Implications on the improvement of somatic embryogenesis in cacao are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

NvERTx: a gene expression database to compare embryogenesis and regeneration in the sea anemone Nematostella vectensis.

PubMed

Warner, Jacob F; Guerlais, Vincent; Amiel, Aldine R; Johnston, Hereroa; Nedoncelle, Karine; Röttinger, Eric

2018-05-17

For over a century, researchers have been comparing embryogenesis and regeneration hoping that lessons learned from embryonic development will unlock hidden regenerative potential. This problem has historically been a difficult one to investigate because the best regenerative model systems are poor embryonic models and vice versa. Recently, however, there has been renewed interest in this question, as emerging models have allowed researchers to investigate these processes in the same organism. This interest has been further fueled by the advent of high-throughput transcriptomic analyses that provide virtual mountains of data. Here, we present N ematostella vectensis Embryogenesis and Regeneration Transcriptomics (NvERTx), a platform for comparing gene expression during embryogenesis and regeneration. NvERTx consists of close to 50 transcriptomic data sets spanning embryogenesis and regeneration in Nematostella These data were used to perform a robust de novo transcriptome assembly, with which users can search, conduct BLAST analyses, and plot the expression of multiple genes during these two developmental processes. The site is also home to the results of gene clustering analyses, to further mine the data and identify groups of co-expressed genes. The site can be accessed at http://nvertx.kahikai.org. © 2018. Published by The Company of Biologists Ltd.

Insights on Structure and Function of a Late Embryogenesis Abundant Protein from Amaranthus cruentus: An Intrinsically Disordered Protein Involved in Protection against Desiccation, Oxidant Conditions, and Osmotic Stress

PubMed Central

Saucedo, Alma L.; Hernández-Domínguez, Eric E.; de Luna-Valdez, Luis A.; Guevara-García, Angel A.; Escobedo-Moratilla, Abraham; Bojorquéz-Velázquez, Esaú; del Río-Portilla, Federico; Fernández-Velasco, Daniel A.; Barba de la Rosa, Ana P.

2017-01-01

Late embryogenesis abundant (LEA) proteins are part of a large protein family that protect other proteins from aggregation due to desiccation or osmotic stresses. Recently, the Amaranthus cruentus seed proteome was characterized by 2D-PAGE and one highly accumulated protein spot was identified as a LEA protein and was named AcLEA. In this work, AcLEA cDNA was cloned into an expression vector and the recombinant protein was purified and characterized. AcLEA encodes a 172 amino acid polypeptide with a predicted molecular mass of 18.34 kDa and estimated pI of 8.58. Phylogenetic analysis revealed that AcLEA is evolutionarily close to the LEA3 group. Structural characteristics were revealed by nuclear magnetic resonance and circular dichroism methods. We have shown that recombinant AcLEA is an intrinsically disordered protein in solution even at high salinity and osmotic pressures, but it has a strong tendency to take a secondary structure, mainly folded as α-helix, when an inductive additive is present. Recombinant AcLEA function was evaluated using Escherichia coli as in vivo model showing the important protection role against desiccation, oxidant conditions, and osmotic stress. AcLEA recombinant protein was localized in cytoplasm of Nicotiana benthamiana protoplasts and orthologs were detected in seeds of wild and domesticated amaranth species. Interestingly AcLEA was detected in leaves, stems, and roots but only in plants subjected to salt stress. This fact could indicate the important role of AcLEA protection during plant stress in all amaranth species studied. PMID:28439280

[Crucial stages of embryogenesis of R. arvalis: Part 1. Linear measurements of embryonic structures].

PubMed

Severtsova, E A; Severtsov, A S

2011-01-01

Investigations of individual variability have allowed us to reveal the crucial (= nodal) stages in embryogenesis of the moor frog (Rana arvalis Nills.). These crucial stages are: the late gastrula stage (stages 18-20), the hatching stages (stages 32-33) and, apparently, early metamorphosis (stage 39). Moreover, we have found that each embryonic structure passes through its specific crucial stages. For example, stage 34 is crucial for the trait "tail width" but is internodal for all other embryonic traits. At this stage, larva passes from an attached to a free-swimming life style. We also found considerable differences between the different frog populations in the the level of developmental variability. These differences were associated with internodal developmental stages.

Normalizing gene expression by quantitative PCR during somatic embryogenesis in two representative conifer species: Pinus pinaster and Picea abies.

PubMed

de Vega-Bartol, José J; Santos, Raquen Raissa; Simões, Marta; Miguel, Célia M

2013-05-01

Suitable internal control genes to normalize qPCR data from different stages of embryo development and germination were identified in two representative conifer species. Clonal propagation by somatic embryogenesis has a great application potentiality in conifers. Quantitative PCR (qPCR) is widely used for gene expression analysis during somatic embryogenesis and embryo germination. No single reference gene is universal, so a systematic characterization of endogenous genes for concrete conditions is fundamental for accuracy. We identified suitable internal control genes to normalize qPCR data obtained at different steps of somatic embryogenesis (embryonal mass proliferation, embryo maturation and germination) in two representative conifer species, Pinus pinaster and Picea abies. Candidate genes included endogenous genes commonly used in conifers, genes previously tested in model plants, and genes with a lower variation of the expression along embryo development according to genome-wide transcript profiling studies. Three different algorithms were used to evaluate expression stability. The geometric average of the expression values of elongation factor-1α, α-tubulin and histone 3 in P. pinaster, and elongation factor-1α, α-tubulin, adenosine kinase and CAC in P. abies were adequate for expression studies throughout somatic embryogenesis. However, improved accuracy was achieved when using other gene combinations in experiments with samples at a single developmental stage. The importance of studies selecting reference genes to use in different tissues or developmental stages within one or close species, and the instability of commonly used reference genes, is highlighted.

Essential role of the TFIID subunit TAF4 in murine embryogenesis and embryonic stem cell differentiation.

PubMed

Langer, Diana; Martianov, Igor; Alpern, Daniel; Rhinn, Muriel; Keime, Céline; Dollé, Pascal; Mengus, Gabrielle; Davidson, Irwin

2016-03-30

TAF4 (TATA-binding protein-associated factor 4) and its paralogue TAF4b are components of the TFIID core module. We inactivated the murine Taf4a gene to address Taf4 function during embryogenesis. Here we show that Taf4a(-/-) embryos survive until E9.5 where primary germ layers and many embryonic structures are identified showing Taf4 is dispensable for their specification. In contrast, Taf4 is required for correct patterning of the trunk and anterior structures, ventral morphogenesis and proper heart positioning. Overlapping expression of Taf4a and Taf4b during embryogenesis suggests their redundancy at early stages. In agreement with this, Taf4a(-/-) embryonic stem cells (ESCs) are viable and comprise Taf4b-containing TFIID. Nevertheless, Taf4a(-/-) ESCs do not complete differentiation into glutamatergic neurons and cardiomyocytes in vitro due to impaired preinitiation complex formation at the promoters of critical differentiation genes. We define an essential role of a core TFIID TAF in differentiation events during mammalian embryogenesis.

Essential role of the TFIID subunit TAF4 in murine embryogenesis and embryonic stem cell differentiation

PubMed Central

Langer, Diana; Martianov, Igor; Alpern, Daniel; Rhinn, Muriel; Keime, Céline; Dollé, Pascal; Mengus, Gabrielle; Davidson, Irwin

2016-01-01

TAF4 (TATA-binding protein-associated factor 4) and its paralogue TAF4b are components of the TFIID core module. We inactivated the murine Taf4a gene to address Taf4 function during embryogenesis. Here we show that Taf4a−/− embryos survive until E9.5 where primary germ layers and many embryonic structures are identified showing Taf4 is dispensable for their specification. In contrast, Taf4 is required for correct patterning of the trunk and anterior structures, ventral morphogenesis and proper heart positioning. Overlapping expression of Taf4a and Taf4b during embryogenesis suggests their redundancy at early stages. In agreement with this, Taf4a−/− embryonic stem cells (ESCs) are viable and comprise Taf4b-containing TFIID. Nevertheless, Taf4a−/− ESCs do not complete differentiation into glutamatergic neurons and cardiomyocytes in vitro due to impaired preinitiation complex formation at the promoters of critical differentiation genes. We define an essential role of a core TFIID TAF in differentiation events during mammalian embryogenesis. PMID:27026076

Proteomic analysis reveals differential accumulation of small heat shock proteins and late embryogenesis abundant proteins between ABA-deficient mutant vp5 seeds and wild-type Vp5 seeds in maize

PubMed Central

Wu, Xiaolin; Gong, Fangping; Yang, Le; Hu, Xiuli; Tai, Fuju; Wang, Wei

2014-01-01

ABA is a major plant hormone that plays important roles during many phases of plant life cycle, including seed development, maturity and dormancy, and especially the acquisition of desiccation tolerance. Understanding of the molecular basis of ABA-mediated plant response to stress is of interest not only in basic research on plant adaptation but also in applied research on plant productivity. Maize mutant viviparous-5 (vp5), deficient in ABA biosynthesis in seeds, is a useful material for studying ABA-mediated response in maize. Due to carotenoid deficiency, vp5 endosperm is white, compared to yellow Vp5 endosperm. However, the background difference at proteome level between vp5 and Vp5 seeds is unclear. This study aimed to characterize proteome alterations of maize vp5 seeds and to identify ABA-dependent proteins during seed maturation. We compared the embryo and endosperm proteomes of vp5 and Vp5 seeds by gel-based proteomics. Up to 46 protein spots, most in embryos, were found to be differentially accumulated between vp5 and Vp5. The identified proteins included small heat shock proteins (sHSPs), late embryogenesis abundant (LEA) proteins, stress proteins, storage proteins and enzymes among others. However, EMB564, the most abundant LEA protein in maize embryo, accumulated in comparable levels between vp5 and Vp5 embryos, which contrasted to previously characterized, greatly lowered expression of emb564 mRNA in vp5 embryos. Moreover, LEA proteins and sHSPs displayed differential accumulations in vp5 embryos: six out of eight identified LEA proteins decreased while nine sHSPs increased in abundance. Finally, we discussed the possible causes of global proteome alterations, especially the observed differential accumulation of identified LEA proteins and sHSPs in vp5 embryos. The data derived from this study provides new insight into ABA-dependent proteins and ABA-mediated response during maize seed maturation. PMID:25653661

Axes, planes and tubes, or the geometry of embryogenesis.

PubMed

Brauckmann, Sabine

2011-12-01

The paper presents selected figures of chick embryogenesis as depicted in the classic studies of Caspar Friedrich Wolff (1734-1794), Christian Heinrich Pander (1794-1865) and Karl Ernst von Baer (1792-1786). My main objective here is (1) to demonstrate how the imagery of Wolff, Pander and Baer attempted to project an image of a 3-dimensional rotating body into static figures on paper by means of linear contours, and (2) to ponder on the efficacy and pervasiveness of dots, lines and arrows for depicting embryogenesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Somatic Embryogenesis in Lisianthus (Eustoma russellianum Griseb.).

PubMed

Ruffoni, Barbara; Bassolino, Laura

2016-01-01

Somatic embryogenesis is, for the main floricultural crops, a promising system for commercial scale-up, providing cloned material to be traded as seedlings. Somatic embryos, having the contemporary presence of root apical meristem and shoot apical meristem, can be readily acclimatized. For Lisianthus it is possible to induce embryogenic callus from leaf fragments of selected genotypes and to obtain embryos either in agarized substrate or in liquid suspension culture. The production of somatic embryos in liquid medium is high and can be modulated in order to synchronize the cycle and the size of the neoformed structures. The possibility to use the liquid substrate with high propagation rates reduces labor costs and could support the costs of eventual automation. In this paper we report a stepwise protocol for somatic embryogenesis in the species Eustoma russellianum.

Somatic embryogenesis from leaf explants of Australian fan flower, Scaevola aemula R. Br.

PubMed

Wang, Y-H; Bhalla, P L

2004-01-01

Somatic embryogenesis from leaf explants of Scaevola aemula R. Br. was achieved. Somatic embryos were induced from explants cultured on MS medium supplemented with 0.2 mg/ 2,4-dichlorophenoxyacetic acid and 0.2-0.5 mg/l 6-benzylaminopurine (BAP). Various developmental stages of somatic embryos were found on this medium-from globular embryos to germinated embryos. The transfer of globular embryos to MS medium containing 0.5 mg/l BAP resulted in a high frequency of shoot regeneration. Leaf explants cultured on MS medium containing different combinations of BAP and alpha-naphthaleneacetic acid formed adventitious shoots and roots. Histological examination confirmed the process of somatic embryogenesis. Induction of somatic embryogenesis in Scaevola provides a system for studying embryogenesis in Australian native plants and will facilitate the improvement of these plants using genetic transformation techniques.

Coordinated metabolic transitions during Drosophila embryogenesis and the onset of aerobic glycolysis.

PubMed

Tennessen, Jason M; Bertagnolli, Nicolas M; Evans, Janelle; Sieber, Matt H; Cox, James; Thummel, Carl S

2014-03-12

Rapidly proliferating cells such as cancer cells and embryonic stem cells rely on a specialized metabolic program known as aerobic glycolysis, which supports biomass production from carbohydrates. The fruit fly Drosophila melanogaster also utilizes aerobic glycolysis to support the rapid growth that occurs during larval development. Here we use singular value decomposition analysis of modENCODE RNA-seq data combined with GC-MS-based metabolomic analysis to analyze the changes in gene expression and metabolism that occur during Drosophila embryogenesis, spanning the onset of aerobic glycolysis. Unexpectedly, we find that the most common pattern of co-expressed genes in embryos includes the global switch to glycolytic gene expression that occurs midway through embryogenesis. In contrast to the canonical aerobic glycolytic pathway, however, which is accompanied by reduced mitochondrial oxidative metabolism, the expression of genes involved in the tricarboxylic cycle (TCA cycle) and the electron transport chain are also upregulated at this time. Mitochondrial activity, however, appears to be attenuated, as embryos exhibit a block in the TCA cycle that results in elevated levels of citrate, isocitrate, and α-ketoglutarate. We also find that genes involved in lipid breakdown and β-oxidation are upregulated prior to the transcriptional initiation of glycolysis, but are downregulated before the onset of larval development, revealing coordinated use of lipids and carbohydrates during development. These observations demonstrate the efficient use of nutrient stores to support embryonic development, define sequential metabolic transitions during this stage, and demonstrate striking similarities between the metabolic state of late-stage fly embryos and tumor cells. Copyright © 2014 Tennessen et al.

Somatic embryogenesis for efficient micropropagation of guava (Psidium guajava L.).

PubMed

Akhtar, Nasim

2013-01-01

Guava (Psidium guajava L.) is well known for edible fruit, environment friendly pharmaceutical and commercial products for both national and international market. The conventional propagation and in vitro organogenesis do not meet the demand for the good quality planting materials. Somatic embryogenesis for efficient micropropagation of guava (P. guajava L.) has been developed to fill up the gap. Somatic embryogenesis and plantlets regeneration are achieved from 10-week post-anthesis zygotic embryo explants by 8-day inductive treatment with different concentrations of 2,4-dichlorophenoxy acetic acid (2,4-D) on MS agar medium containing 5% sucrose. Subsequent development and maturation of somatic embryos occur after 8 days on MS basal medium supplemented with 5% sucrose without plant growth regulator. The process of somatic embryogenesis shows the highest relative efficiency in 8-day treatment of zygotic embryo explants with 1.0 mg L(-1) 2,4-D. High efficiency germination of somatic embryos and plantlet regeneration takes place on half strength semisolid MS medium amended with 3% sucrose within 2 weeks of subculture. Somatic plantlets are grown for additional 2 weeks by subculturing in MS liquid growth medium containing 3% sucrose. Well-grown plantlets from liquid medium have survived very well following 2-4 week hardening process. The protocol of somatic embryogenesis is optimized for high efficiency micropropagation of guava species.

Somatic Embryogenesis in Two Orchid Genera (Cymbidium, Dendrobium).

PubMed

da Silva, Jaime A Teixeira; Winarto, Budi

2016-01-01

The protocorm-like body (PLB) is the de facto somatic embryo in orchids. Here we describe detailed protocols for two orchid genera (hybrid Cymbidium Twilight Moon 'Day Light' and Dendrobium 'Jayakarta', D. 'Gradita 31', and D. 'Zahra FR 62') for generating PLBs. These protocols will most likely have to be tweaked for different cultivars as the response of orchids in vitro tends to be dependent on genotype. In addition to primary somatic embryogenesis, secondary (or repetitive) somatic embryogenesis is also described for both genera. The use of thin cell layers as a sensitive tissue assay is outlined for hybrid Cymbidium while the protocol outlined is suitable for bioreactor culture of D. 'Zahra FR 62'.

A Group 6 Late Embryogenesis Abundant Protein from Common Bean Is a Disordered Protein with Extended Helical Structure and Oligomer-forming Properties*

PubMed Central

Rivera-Najera, Lucero Y.; Saab-Rincón, Gloria; Battaglia, Marina; Amero, Carlos; Pulido, Nancy O.; García-Hernández, Enrique; Solórzano, Rosa M.; Reyes, José L.; Covarrubias, Alejandra A.

2014-01-01

Late embryogenesis-abundant proteins accumulate to high levels in dry seeds. Some of them also accumulate in response to water deficit in vegetative tissues, which leads to a remarkable association between their presence and low water availability conditions. A major sub-group of these proteins, also known as typical LEA proteins, shows high hydrophilicity and a high percentage of glycine and other small amino acid residues, distinctive physicochemical properties that predict a high content of structural disorder. Although all typical LEA proteins share these characteristics, seven groups can be distinguished by sequence similarity, indicating structural and functional diversity among them. Some of these groups have been extensively studied; however, others require a more detailed analysis to advance in their functional understanding. In this work, we report the structural characterization of a group 6 LEA protein from a common bean (Phaseolus vulgaris L.) (PvLEA6) by circular dichroism and nuclear magnetic resonance showing that it is a disordered protein in aqueous solution. Using the same techniques, we show that despite its unstructured nature, the addition of trifluoroethanol exhibited an intrinsic potential in this protein to gain helicity. This property was also promoted by high osmotic potentials or molecular crowding. Furthermore, we demonstrate that PvLEA6 protein is able to form soluble homo-oligomeric complexes that also show high levels of structural disorder. The association between PvLEA6 monomers to form dimers was shown to occur in plant cells by bimolecular fluorescence complementation, pointing to the in vivo functional relevance of this association. PMID:25271167

Effect of Salicylic Acid on Somatic Embryogenesis and Plant Regeneration in Hedychium bousigonianum

USDA-ARS?s Scientific Manuscript database

The objective of this study was to induce somatic embryogenesis in Hedychium bousigonianum Pierre ex Gagnepain and assess the influence of salicylic acid (S) on somatic embryogenesis. Somatic embryos and subsequently regenerated plants were successfully obtained 30 days after transfer of embryogenic...

Abscisic Acid-Dependent and -Independent Expression of the Carrot Late-Embryogenesis-Abundant-Class Gene Dc3 in Transgenic Tobacco Seedlings1

PubMed Central

Siddiqui, Najeeb U.; Chung, Hwa-Jee; Thomas, Terry L.; Drew, Malcolm C.

1998-01-01

We studied the expression of three promoter 5′ deletion constructs (−218, −599, and −1312) of the LEA (late embryogenesis abundant)-class gene Dc3 fused to β-glucuronidase (GUS), where each construct value refers to the number of base pairs upstream of the transcription start site at which the deletion occurred. The Dc3 gene is noted for its induction by abscisic acid (ABA), but its response to other plant hormones and various environmental stresses has not been reported previously for vegetative cells. Fourteen-day-old transgenic tobacco (Nicotiana tabacum L.) seedlings were exposed to dehydration, hypoxia, salinity, exogenous ethylene, or exogenous methyl jasmonate (MeJa). GUS activity was quantified fluorimetrically and expression was observed by histochemical staining of the seedlings. An increase in GUS activity was observed in plants with constructs −599 and −1312 in response to dehydration and salinity within 6 h of stress, and at 12 h in response to hypoxia. No increase in endogenous ABA was found in any of the three lines, even after 72 h of hypoxia. An ABA-independent increase in GUS activity was observed when endogenous ABA biosynthesis was blocked by fluridone and plants were exposed to 5 μL L−1 ethylene in air or 100 μm MeJa. Virtually no expression was observed in construct −218 in response to dehydration, salinity, or MeJa, but there was a moderate response to ethylene and hypoxia. This suggests that the region between −218 and −599 is necessary for ABA (dehydration and salinity)- and MeJa-dependent expression, whereas ethylene-mediated expression does not require this region of the promoter. PMID:9847092

Differential proteome analysis during early somatic embryogenesis in Musa spp. AAA cv. Grand Naine.

PubMed

Kumaravel, Marimuthu; Uma, Subbaraya; Backiyarani, Suthanthiram; Saraswathi, Marimuthu Somasundaram; Vaganan, Muthu Mayil; Muthusamy, Muthusamy; Sajith, Kallu Purayil

2017-01-01

Endogenous hormone secretion proteins along with stress and defense proteins play predominant role in banana embryogenesis. This study reveals the underlying molecular mechanism during transition from vegetative to embryogenic state. Banana (Musa spp.) is well known globally as a food fruit crop for millions. The requirement of quality planting material of banana is enormous. Although mass multiplication through tissue culture is in vogue, high-throughput techniques like somatic embryogenesis (SE) as a mass multiplication tool needs to be improved. Apart from clonal propagation, SE has extensive applications in genetic improvement and mutation. SE in banana is completely genome-dependent and most of the commercial cultivars exhibit recalcitrance. Thus, understanding the molecular basis of embryogenesis in Musa will help to develop strategies for mass production of quality planting material. In this study, differentially expressed proteins between embryogenic calli (EC) and non-embryogenic calli (NEC) with respect to the explant, immature male flower buds (IMFB), of cv. Grand Naine (AAA) were determined using two-dimensional gel electrophoresis (2DE). The 2DE results were validated through qRT-PCR. In total, 65 proteins were identified: 42 were highly expressed and 23 were less expressed in EC compared to NEC and IMFB. qRT-PCR analysis of five candidate proteins, upregulated in EC, were well correlated with expression at transcript level. Further analysis of proteins showed that embryogenesis in banana is associated with the control of oxidative stress. The regulation of ROS scavenging system and protection of protein structure occurred in the presence of heat shock proteins. Alongside, high accumulation of stress-related cationic peroxidase and plant growth hormone-related proteins like indole-3-pyruvate monooxygenase and adenylate isopentenyltransferase in EC revealed the association with the induction of SE.

Shoot regeneration and somatic embryogenesis from needles of redwood (Sequoia sempervirens (D.Don.) Endl.).

PubMed

Liu, Cuiqiong; Xia, Xinli; Yin, Weilun; Huang, Lichun; Zhou, Jianghong

2006-07-01

A rapid and effective system of somatic embryogenesis and organogenesis from the in vitro needles of redwood (Sequoia sempervirens (D.Don.) Endl.) had been established. The influences of plant growth regulators (PGRs) and days of seedlings in vitro on adventitious bud regeneration and somatic embryogenesis were studied. The process of somatic embryo formation was also observed. The results showed that embryogenic callus was induced and proliferated on Schenk and Hildebrandt (SH) medium with BA (0.5 mg/l), KT (0.5 mg/l) and IBA (1.0 mg/l). SH medium containing BA (0.5 mg/l), KT (0.2 mg/l) and IBA (0.2 mg/l) effectively promoted adventitious bud regeneration. The highest frequency (66.3%) of direct somatic embryogenesis was obtained in the combination of BA (0.5 mg/l) and IBA (0.5 mg/l). The optimal days of seedling in vitro for adventitious bud and somatic embryogenesis were 30 days and 30-40 days, respectively. The developments of somatic embryos were similar to that of zygotic embryogenesis. The result of histocytological studies indicated that proteins were gradually accumulated in the process of somatic embryo formation and there were two peaks of starch grains accumulation that one was in the embryogenic callus and the other was in the globular embryos. These results indicated that starch and protein were closely related with the energy supply and the molecular base of somatic embryogenesis, respectively.

Diverse roles of actin in C. elegans early embryogenesis

PubMed Central

Velarde, Nathalie; Gunsalus, Kristin C; Piano, Fabio

2007-01-01

Background The actin cytoskeleton plays critical roles in early development in Caenorhabditis elegans. To further understand the complex roles of actin in early embryogenesis we use RNAi and in vivo imaging of filamentous actin (F-actin) dynamics. Results Using RNAi, we found processes that are differentially sensitive to levels of actin during early embryogenesis. Mild actin depletion shows defects in cortical ruffling, pseudocleavage, and establishment of polarity, while more severe depletion shows defects in polar body extrusion, cytokinesis, chromosome segregation, and eventually, egg production. These defects indicate that actin is required for proper oocyte development, fertilization, and a wide range of important events during early embryogenesis, including proper chromosome segregation. In vivo visualization of the cortical actin cytoskeleton shows dynamics that parallel but are distinct from the previously described myosin dynamics. Two distinct types of actin organization are observed at the cortex. During asymmetric polarization to the anterior, or the establishment phase (Phase I), actin forms a meshwork of microfilaments and focal accumulations throughout the cortex, while during the anterior maintenance phase (Phase II) it undergoes a morphological transition to asymmetrically localized puncta. The proper asymmetric redistribution is dependent on the PAR proteins, while both asymmetric redistribution and morphological transitions are dependent upon PFN-1 and NMY-2. Just before cytokinesis, actin disappears from most of the cortex and is only found around the presumptive cytokinetic furrow. Finally, we describe dynamic actin-enriched comets in the early embryo. Conclusion During early C. elegans embryogenesis actin plays more roles and its organization is more dynamic than previously described. Morphological transitions of F-actin, from meshwork to puncta, as well as asymmetric redistribution, are regulated by the PAR proteins. Results from this study

Construction of a high-density linkage map and mapping quantitative trait loci for somatic embryogenesis using leaf petioles as explants in upland cotton (Gossypium hirsutum L.).

PubMed

Xu, Zhenzhen; Zhang, Chaojun; Ge, Xiaoyang; Wang, Ni; Zhou, Kehai; Yang, Xiaojie; Wu, Zhixia; Zhang, Xueyan; Liu, Chuanliang; Yang, Zuoren; Li, Changfeng; Liu, Kun; Yang, Zhaoen; Qian, Yuyuan; Li, Fuguang

2015-07-01

The first high-density linkage map was constructed to identify quantitative trait loci (QTLs) for somatic embryogenesis (SE) in cotton ( Gossypium hirsutum L.) using leaf petioles as explants. Cotton transformation is highly limited by only a few regenerable genotypes and the lack of understanding of the genetic and molecular basis of somatic embryogenesis (SE) in cotton (Gossypium hirsutum L.). To construct a more saturated linkage map and further identify quantitative trait loci (QTLs) for SE using leaf petioles as explants, a high embryogenesis frequency line (W10) from the commercial Chinese cotton cultivar CRI24 was crossed with TM-1, a genetic standard upland cotton with no embryogenesis frequency. The genetic map spanned 2300.41 cM in genetic distance and contained 411 polymorphic simple sequence repeat (SSR) loci. Of the 411 mapped loci, 25 were developed from unigenes identified for SE in our previous study. Six QTLs for SE were detected by composite interval mapping method, each explaining 6.88-37.07% of the phenotypic variance. Single marker analysis was also performed to verify the reliability of QTLs detection, and the SSR markers NAU3325 and DPL0209 were detected by the two methods. Further studies on the relatively stable and anchoring QTLs/markers for SE in an advanced population of W10 × TM-1 and other cross combinations with different SE abilities may shed light on the genetic and molecular mechanism of SE in cotton.

Ectopic expression of the Coffea canephora SERK1 homolog-induced differential transcription of genes involved in auxin metabolism and in the developmental control of embryogenesis.

PubMed

Pérez-Pascual, Daniel; Jiménez-Guillen, Doribet; Villanueva-Alonzo, Hernán; Souza-Perera, Ramón; Godoy-Hernández, Gregorio; Zúñiga-Aguilar, José Juan

2018-04-01

Somatic embryogenesis receptor-like kinase 1 (SERK1) is a membrane receptor that might serve as common co-regulator of plant cell differentiation processes by forming heterodimers with specific receptor-like kinases. The Coffea canephora SERK1 homolog (CcSERK1) was cloned in this work, and its early function in the transcription of embryogenesis master genes and of genes encoding proteins involved in auxin metabolism was investigated by externally manipulating its expression in embryogenic leaf explants, before the appearance of embryogenic structures. Overexpression of CcSERK1 early during embryogenesis caused an increase in the number of somatic embryos when the 55-day process was completed. Suppression of CcSERK1 expression by RNA interference almost abolished somatic embryogenesis. Real time-PCR experiments revealed that the transcription of the CcAGL15, CcWUS, CcBBM, CcPKL, CcYUC1, CcPIN1 and CcPIN4 homologs was modified in direct proportion to the expression of CcSERK1 and that only CcLEC1 was inversely affected by the expression levels of CcSERK1. The expression of the CcYUC4 homolog was induced to more than 80-fold under CcSERK1 overexpression conditions, but it was also induced when CcSERK1 expression was silenced. The level of CcTIR1 was not affected by CcSERK1 overexpression but was almost abolished during CcSERK1 silencing. These results suggest that CcSERK1 co-regulates the induction of somatic embryogenesis in Coffea canephora by early activation of YUC-dependent auxin biosynthesis, auxin transport mediated by PIN1 and PIN4, and probably auxin perception by the TIR1 receptor, leading to the induction of early-stage homeotic genes (CcAGL15, CcWUS, CcPKL and CcBBM) and repression of late-stage homeotic genes (CcLec1). © 2018 Scandinavian Plant Physiology Society.

Localization and identification of phenolic compounds in Theobroma cacao L. somatic embryogenesis.

PubMed

Alemanno, L; Ramos, T; Gargadenec, A; Andary, C; Ferriere, N

2003-10-01

Cocoa breeders and growers continue to face the problem of high heterogeneity between individuals derived from one progeny. Vegetative propagation by somatic embryogenesis could be a way to increase genetic gains in the field. Somatic embryogenesis in cocoa is difficult and this species is considered as recalcitrant. This study was conducted to investigate the phenolic composition of cocoa flowers (the explants used to achieve somatic embryogenesis) and how it changes during the process, by means of histochemistry and conventional chemical techniques. In flowers, all parts contained polyphenolics but their locations were specific to the organ considered. After placing floral explants in vitro, the polyphenolic content was qualitatively modified and maintained in the calli throughout the culture process. Among the new polyphenolics, the three most abundant were isolated and characterized by 1H- and 13C-NMR. They were hydroxycinnamic acid amides: N-trans-caffeoyl-l-DOPA or clovamide, N-trans-p-coumaroyl-l-tyrosine or deoxiclovamide, and N-trans-caffeoyl-l-tyrosine. The same compounds were found also in fresh, unfermented cocoa beans. The synthesis kinetics for these compounds in calli, under different somatic embryogenesis conditions, revealed a higher concentration under non-embryogenic conditions. Given the antioxidant nature of these compounds, they could reflect the stress status of the tissues.

Localization and Identification of Phenolic Compounds in Theobroma cacao L. Somatic Embryogenesis

PubMed Central

ALEMANNO, L.; RAMOS, T.; GARGADENEC, A.; ANDARY, C.; FERRIERE, N.

2003-01-01

Cocoa breeders and growers continue to face the problem of high heterogeneity between individuals derived from one progeny. Vegetative propagation by somatic embryogenesis could be a way to increase genetic gains in the field. Somatic embryogenesis in cocoa is difficult and this species is considered as recalcitrant. This study was conducted to investigate the phenolic composition of cocoa flowers (the explants used to achieve somatic embryogenesis) and how it changes during the process, by means of histochemistry and conventional chemical techniques. In flowers, all parts contained polyphenolics but their locations were specific to the organ considered. After placing floral explants in vitro, the polyphenolic content was qualitatively modified and maintained in the calli throughout the culture process. Among the new polyphenolics, the three most abundant were isolated and characterized by 1H‐ and 13C‐NMR. They were hydroxycinnamic acid amides: N‐trans‐caffeoyl‐l‐DOPA or clovamide, N‐trans‐p‐coumaroyl‐l‐tyrosine or deoxiclovamide, and N‐trans‐caffeoyl‐l‐tyrosine. The same compounds were found also in fresh, unfermented cocoa beans. The synthesis kinetics for these compounds in calli, under different somatic embryogenesis conditions, revealed a higher concentration under non‐embryogenic conditions. Given the antioxidant nature of these compounds, they could reflect the stress status of the tissues. PMID:12933367

Studies on Somatic Embryogenesis in Sweetpotato

NASA Technical Reports Server (NTRS)

Bennett, J. Rasheed; Prakash, C. S.

1997-01-01

The purpose of this study was to improve the somatic embryo (SE) system for plant production of sweetpotato Ipomoea batatas L.(Lam)l. Explants isolated from SE-derived sweet potato plants were compared with control (non SE-derived) plants for their competency for SE production. Leaf explants were cultured on Murashige-Skoog (MS) medium with 2,4-dichlorophenoxy acetic acid (0.2 mg/L) and 6-benzylaminopurine (2.5 mg/L) for 2 weeks in darkness and transferred to MS medium with abscisic acid (2.5 Explants isolated from those plants developed through somatic embryo-genesis produced new somatic embryos rapidly and in higher frequency than those isolated from control plants. They also appeared to grow faster in tissue culture than the control plants. Current studies in the laboratory are examining whether plants derived from a cyclical embryogenesis system (five cycles) would have any further positive impact on the rapidity and frequency of somatic embryo development. More detailed studies using electron microscopy are expected to show the point of origin of the embryos and to allow determination of their quality throughout the cyclical process. This study may facilitate improved plant micropropagation, gene transfer and germplasm conservation in sweet potato.

Developmental origins of neurotransmitter and transcriptome alterations in adult female zebrafish exposed to atrazine during embryogenesis.

PubMed

Wirbisky, Sara E; Weber, Gregory J; Sepúlveda, Maria S; Xiao, Changhe; Cannon, Jason R; Freeman, Jennifer L

2015-07-03

Atrazine is an herbicide applied to agricultural crops and is indicated to be an endocrine disruptor. Atrazine is frequently found to contaminate potable water supplies above the maximum contaminant level of 3μg/L as defined by the U.S. Environmental Protection Agency. The developmental origin of adult disease hypothesis suggests that toxicant exposure during development can increase the risk of certain diseases during adulthood. However, the molecular mechanisms underlying disease progression are still unknown. In this study, zebrafish embryos were exposed to 0, 0.3, 3, or 30μg/L atrazine throughout embryogenesis. Larvae were then allowed to mature under normal laboratory conditions with no further chemical treatment until 7 days post fertilization (dpf) or adulthood and neurotransmitter analysis completed. No significant alterations in neurotransmitter levels was observed at 7dpf or in adult males, but a significant decrease in 5-hydroxyindoleacetic acid (5-HIAA) and serotonin turnover was seen in adult female brain tissue. Transcriptomic analysis was completed on adult female brain tissue to identify molecular pathways underlying the observed neurological alterations. Altered expression of 1928, 89, and 435 genes in the females exposed to 0.3, 3, or 30μg/L atrazine during embryogenesis were identified, respectively. There was a high level of overlap between the biological processes and molecular pathways in which the altered genes were associated. Moreover, a subset of genes was down regulated throughout the serotonergic pathway. These results provide support of the developmental origins of neurological alterations observed in adult female zebrafish exposed to atrazine during embryogenesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Flow cytometric and morphological analyses of Pinus pinaster somatic embryogenesis.

PubMed

Marum, Liliana; Loureiro, João; Rodriguez, Eleazar; Santos, Conceição; Oliveira, M Margarida; Miguel, Célia

2009-09-25

An approach combining morphological profiling and flow cytometric analysis was used to assess genetic stability during the several steps of somatic embryogenesis in Pinus pinaster. Embryogenic cell lines of P. pinaster were established from immature zygotic embryos excised from seeds obtained from open-pollinated trees. During the maturation stage, phenotype of somatic embryos was characterized as being either normal or abnormal. Based upon the prevalent morphological traits, different types of abnormal embryos underwent further classification and quantification. Nuclear DNA content of maritime pine using the zygotic embryos was estimated to be 57.04 pg/2C, using propidium iodide flow cytometry. According to the same methodology, no significant differences (P< or =0.01) in DNA ploidy were detected among the most frequently observed abnormal phenotypes, embryogenic cell lines, zygotic and normal somatic embryos, and somatic embryogenesis-derived plantlets. Although the differences in DNA ploidy level do not exclude the occurrence of a low level of aneuploidy, the results obtained point to the absence of major changes in ploidy level during the somatic embryogenesis process of this economically important species. Therefore, our primary goal of true-to-typeness was assured at this level.

Identifying and Investigating the Late-1960s Interhemispheric SST Shift

NASA Astrophysics Data System (ADS)

Friedman, A. R.; Lee, S. Y.; Liu, Y.; Chiang, J. C. H.

2014-12-01

The global north-south interhemispheric sea surface temperature (SST) difference experienced a pronounced and rapid decrease in the late 1960s, which has been linked to drying in the Sahel, South Asia, and East Asia. However, some basic questions about the interhemispheric SST shift remain unresolved, including its scale and whether the constituent changes in different basins were coordinated. In this study, we systematically investigate the spatial and temporal behavior of the late-1960s interhemispheric SST shift using ocean surface and subsurface observations. We also evaluate potential mechanisms using control and specific-forcing CMIP5 simulations. Using a regime shift detection technique, we identify the late-1960s shift as the most prominent in the historical observational SST record. We additionally examine the corresponding changes in upper-ocean heat content and salinity associated with the shift. We find that there were coordinated upper-ocean cooling and freshening in the subpolar North Atlantic, the region of the largest-magnitude SST decrease during the interhemispheric shift. These upper-ocean changes correspond to a weakened North Atlantic thermohaline circulation (THC). However, the THC decrease does not fully account for the rapid global interhemispheric SST shift, particularly the warming in the extratropical Southern Hemisphere.

Conformation of a Group 2 Late Embryogenesis Abundant Protein from Soybean. Evidence of Poly (l-Proline)-type II Structure1

PubMed Central

Soulages, Jose L.; Kim, Kangmin; Arrese, Estela L.; Walters, Christina; Cushman, John C.

2003-01-01

Late embryogenesis abundant (LEA) proteins are members of a large group of hydrophilic, glycine-rich proteins found in plants, algae, fungi, and bacteria known collectively as hydrophilins that are preferentially expressed in response to dehydration or hyperosmotic stress. Group 2 LEA (dehydrins or responsive to abscisic acid) proteins are postulated to stabilize macromolecules against damage by freezing, dehydration, ionic, or osmotic stress. However, the structural and physicochemical properties of group 2 LEA proteins that account for such functions remain unknown. We have analyzed the structural properties of a recombinant form of a soybean (Glycine max) group 2 LEA (rGmDHN1). Differential scanning calorimetry of purified rGmDHN1 demonstrated that the protein does not display a cooperative unfolding transition upon heating. Ultraviolet absorption and circular dichroism spectroscopy revealed that the protein is in a largely hydrated and unstructured conformation in solution. However, ultraviolet absorption and circular dichroism measurements collected at different temperatures showed that the protein exists in equilibrium between two extended conformational states: unordered and left-handed extended helical or poly (l-proline)-type II structures. It is estimated that 27% of the residues of rGmDHN1 adopt or poly (l-proline)-type II-like helical conformation at 12°C. The content of extended helix gradually decreases to 15% as the temperature is increased to 80°C. Studies of the conformation of the protein in solution in the presence of liposomes, trifluoroethanol, and sodium dodecyl sulfate indicated that rGmDHN1 has a very low intrinsic ability to adopt α-helical structure and to interact with phospholipid bilayers through amphipathic α-helices. The ability of the protein to remain in a highly extended conformation at low temperatures could constitute the basis of the functional role of GmDHN1 in the prevention of freezing, desiccation, ionic, or osmotic

LONO1 Encoding a Nucleoporin Is Required for Embryogenesis and Seed Viability in Arabidopsis1[C][W][OA

PubMed Central

Braud, Christopher; Zheng, Wenguang; Xiao, Wenyan

2012-01-01

Early embryogenesis in Arabidopsis (Arabidopsis thaliana) is distinguished by a predictable pattern of cell divisions and is a good system for investigating mechanisms of developmental pattern formation. Here, we identified a gene called LONO1 (LNO1) in Arabidopsis in which mutations can abolish the first asymmetrical cell division of the zygote, alter planes and number of cell divisions in early embryogenesis, and eventually arrest embryo development. LNO1 is highly expressed in anthers of flower buds, stigma papilla of open flowers, and embryo and endosperm during early embryogenesis, which is correlated with its functions in reproductive development. The homozygous lno1-1 seed is not viable. LNO1, a homolog of the nucleoporin NUP214 in human (Homo sapiens) and Nup159 in yeast (Saccharomyces cerevisiae), encodes a nucleoporin protein containing phenylalanine-glycine repeats in Arabidopsis. We demonstrate that LNO1 can functionally complement the defect in the yeast temperature-sensitive nucleoporin mutant nup159. We show that LNO1 specifically interacts with the Arabidopsis DEAD-box helicase/ATPase LOS4 in the yeast two-hybrid assay. Furthermore, mutations in AtGLE1, an Arabidopsis homolog of the yeast Gle1 involved in the same poly(A) mRNA export pathway as Nup159, also result in seed abortion. Our results suggest that LNO1 is a component of the nuclear pore complex required for mature mRNA export from the nucleus to the cytoplasm, which makes LNO1 essential for embryogenesis and seed viability in Arabidopsis. PMID:22898497

Identification and characterization of bZIP-type transcription factors involved in carrot (Daucus carota L.) somatic embryogenesis.

PubMed

Guan, Yucheng; Ren, Haibo; Xie, He; Ma, Zeyang; Chen, Fan

2009-10-01

Seed dormancy is an important adaptive trait that enables seeds of many species to remain quiescent until conditions become favorable for germination. Abscisic acid (ABA) plays an important role in these developmental processes. Like dormancy and germination, the elongation of carrot somatic embryo radicles is retarded by sucrose concentrations at or above 6%, and normal growth resumes at sucrose concentrations below 3%. Using a yeast one-hybrid screening system, we isolated two bZIP-type transcription factors, CAREB1 and CAREB2, from a cDNA library prepared from carrot somatic embryos cultured in a high-sucrose medium. Both CAREB1 and CAREB2 were localized to the nucleus, and specifically bound to the ABA response element (ABRE) in the Dc3 promoter. Expression of CAREB2 was induced in seedlings by drought and exogenous ABA application; whereas expression of CAREB1 increased during late embryogenesis, and reduced dramatically when somatic embryos were treated with fluridone, an inhibitor of ABA synthesis. Overexpression of CAREB1 caused somatic embryos to develop slowly when cultured in low-sucrose medium, and retarded the elongation of the radicles. These results indicate that CAREB1 and CAREB2 have similar DNA-binding activities, but play different roles during carrot development. Our results indicate that CAREB1 functions as an important trans-acting factor in the ABA signal transduction pathway during carrot somatic embryogenesis.

Cracking the egg: virtual embryogenesis of real robots.

PubMed

Cussat-Blanc, Sylvain; Pollack, Jordan

2014-01-01

All multicellular living beings are created from a single cell. A developmental process, called embryogenesis, takes this first fertilized cell down a complex path of reproduction, migration, and specialization into a complex organism adapted to its environment. In most cases, the first steps of the embryogenesis take place in a protected environment such as in an egg or in utero. Starting from this observation, we propose a new approach to the generation of real robots, strongly inspired by living systems. Our robots are composed of tens of specialized cells, grown from a single cell using a bio-inspired virtual developmental process. Virtual cells, controlled by gene regulatory networks, divide, migrate, and specialize to produce the robot's body plan (morphology), and then the robot is manually built from this plan. Because the robot is as easy to assemble as Lego, the building process could be easily automated.

Hemoglobins, programmed cell death and somatic embryogenesis.

PubMed

Hill, Robert D; Huang, Shuanglong; Stasolla, Claudio

2013-10-01

Programmed cell death (PCD) is a universal process in all multicellular organisms. It is a critical component in a diverse number of processes ranging from growth and differentiation to response to stress. Somatic embryogenesis is one such process where PCD is significantly involved. Nitric oxide is increasingly being recognized as playing a significant role in regulating PCD in both mammalian and plant systems. Plant hemoglobins scavenge NO, and evidence is accumulating that events that modify NO levels in plants also affect hemoglobin expression. Here, we review the process of PCD, describing the involvement of NO and plant hemoglobins in the process. NO is an effector of cell death in both plants and vertebrates, triggering the cascade of events leading to targeted cell death that is a part of an organism's response to stress or to tissue differentiation and development. Expression of specific hemoglobins can alter this response in plants by scavenging the NO, thus, interrupting the death process. Somatic embryogenesis is used as a model system to demonstrate how cell-specific expression of different classes of hemoglobins can alter the embryogenic process, affecting hormone synthesis, cell metabolite levels and genes associated with PCD and embryogenic competence. We propose that plant hemoglobins influence somatic embryogenesis and PCD through cell-specific expression of a distinct plant hemoglobin. It is based on the premise that both embryogenic competence and PCD are strongly influenced by cellular NO levels. Increases in cellular NO levels result in elevated Zn(2+) and reactive-oxygen species associated with PCD, but they also result in decreased expression of MYC2, a transcription factor that is a negative effector of indoleacetic acid synthesis, a hormone that positively influences embryogenic competence. Cell-specific hemoglobin expression reduces NO levels as a result of NO scavenging, resulting in cell survival. Copyright © 2013 Elsevier Ireland Ltd

Somatic embryogenesis in Carica papaya as affected by auxins and explants, and morphoanatomical-related aspects.

PubMed

Cipriano, Jamile L D; Cruz, Ana Cláudia F; Mancini, Karina C; Schmildt, Edilson R; Lopes, José Carlos; Otoni, Wagner C; Alexandre, Rodrigo S

2018-01-01

The aim of this study was to evaluate somatic embryogenesis in juvenile explants of the THB papaya cultivar. Apical shoots and cotyledonary leaves were inoculated in an induction medium composed of different concentrations of 2,4-D (6, 9, 12, 15 and 18 µM) or 4-CPA (19, 22, 25, 28 and 31 µM). The embryogenic calluses were transferred to a maturation medium for 30 days. Histological analysis were done during the induction and scanning electron microscopy after maturing. For both types of auxin, embryogenesis was achieved at higher frequencies with cotyledonary leaves incubated in induction medium than with apical shoots; except for callogenesis. The early-stage embryos (e.g., globular or heart-shape) predominated. Among the auxins, best results were observed in cotyledonary leaves induced with 4-CPA (25 µM). Histological analyses of the cotyledonary leaf-derived calluses confirmed that the somatic embryos (SEs) formed from parenchyma cells, predominantly differentiated via indirect and multicellular origin and infrequently via synchronized embryogenesis. The secondary embryogenesis was observed during induction and maturation phases in papaya THB cultivar. The combination of ABA (0.5 µM) and AC (15 g L-1) in maturation medium resulted in the highest somatic embryogenesis induction frequency (70 SEs callus-1) and the lowest percentage of early germination (4%).

IDENTIFYING NEARBY, YOUNG, LATE-TYPE STARS BY MEANS OF THEIR CIRCUMSTELLAR DISKS

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

Schneider, Adam; Song, Inseok; Melis, Carl

2012-10-01

It has recently been shown that a significant fraction of late-type members of nearby, very young associations (age {approx}<10 Myr) display excess emission at mid-IR wavelengths indicative of dusty circumstellar disks. We demonstrate that the detection of mid-IR excess emission can be utilized to identify new nearby, young, late-type stars including two definite new members ('TWA 33' and 'TWA 34') of the TW Hydrae Association (TWA). Both new TWA members display mid-IR excess emission in the Wide-field Infrared Survey Explorer catalog and they show proper motion and youthful spectroscopic characteristics-namely, H{alpha} emission, strong lithium absorption, and low surface gravity featuresmore » consistent with known TWA members. We also detect mid-IR excess-the first unambiguous evidence of a dusty circumstellar disk-around a previously identified UV-bright, young, accreting star (2M1337) that is a likely member of the Lower-Centaurus Crux region of the Scorpius-Centaurus Complex.« less

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.

Immunocytochemical localisation of the nucleolar protein fibrillarin and RNA polymerase I during mouse early embryogenesis.

PubMed

Cuadros-Fernández, J M; Esponda, P

1996-02-01

We have employed immunocytochemical procedures to localise the nucleolar protein fibrillarin and the enzyme RNA polymerase I in the numerous dense fibrillar bodies (nucleolar precursor bodies) which appear in the nuclei of mammalian early embryos. The aim of this study was to search for relationships between the localisation of these proteins, the changes in the structure of the nucleolar precursor bodies and the resumption of rRNA gene transcription during mouse early embryogenesis. Three human autoimmune sera which recognised fibrillarin and a rabbit antiserum created against RNA polymerase I were employed for fluorescence and electron microscopic immunocytochemical assays. A statistical analysis was also applied. Immunocytochemistry revealed that fibrillarin and RNA polymerase I showed the same localisation in the nucleolar precursor bodies. These proteins were immunolocalised only from the late 2-cell stage onward. Fibrillarin was initially detected at the periphery of the nucleolar precursor bodies and the labelling gradually increased until the morula and blastocyst stages, where normally active nucleoli are found. The pattern of increase of fibrillarin during early embryogenesis shows a parallelism with the rise in rRNA gene transcription occurring during these embryonic stages, and a possible correlation between these two phenomena is suggested. Results demonstrated that nucleolar precursor bodies differ in their biochemical composition from the nucleolus and also from the prenucleolar bodies which appear during mitosis. When anti-fibrillarin antibodies were microinjected into the male pronucleus of mouse embryos to analyse the functions of fibrillarin during early development, they partially blocked the early development of mouse embryos and only 23.8% of injected embryos reach the blastocyst stage.

In vitro somatic embryogenesis and plant regeneration of cassava.

PubMed

Szabados, L; Hoyos, R; Roca, W

1987-06-01

An efficient and reproducible plant regeneration system, initiated in somatic tissues, has been devised for cassava (Manihot esculenta Crantz). Somatic embryogenesis has been induced from shoot tips and immature leaves of in vitro shoot cultures of 15 cassava genotypes. Somatic embryos developed directly on the explants when cultured on a medium containing 4-16 mg/l 2,4-D. Differences were observed with respect to the embryogenic capacity of the explants of different varieties. Secondary embryogenesis has been induced by subculture on solid or liquid induction medium. Long term cultures were established and maintained for up to 18 months by repeated subculture of the proliferating somatic embryos. Plantlets developed from primary and secondary embryos in the presence of 0.1 mg/l BAP, 1mg/l GA3, and 0.01 mg/l 2,4-D. Regenerated plants were transferred to the field, and were grown to maturity.

[Changes in polyamine levels in Citrus sinensis Osb. cv. Valencia callus during somatic embryogenesis].

PubMed

Liu, Hua-Ying; Xiao, Lang-Tao; Lu, Xu-Dong; Hu, Jia-Jin; Wu, Shun; He, Chang-Zheng; Deng, Xiu-Xin

2005-06-01

Somatic embryogenetic capability and changes in polyamine level and their relationship were analyzed using the long-term (8 years) subcultured calli of Citrus sinensis Osb. cv. Valencia as materials. The results showed that endogenous polyamine contents in embryogenic calli were higher than those in non-embryogenic calli, and the embryogenetic capability was positively correlated to the levels of endogenous polyamines. When the calli were transferred to a differentiation medium, the putrescine content rapidly increased and reached a peak, then fell gradually. Applying exogenous putrescine raised the embryogenesis frequency and endogenous putrescine level. It indicated that increase in putrescine content at early stage of differentiation promoted embryogenesis. With the development of somatic embryo, spermidine content reached its the highest level at globular embryo stage, spermine content rose and reached a peak at a later stage of globular embryo development. Furthermore, changes of the putrescine, spermidine and spermine contents during somatic embryogenesis were similar in Valencia calli which had different ploidy levels, but their contents decreased following the increasing of ploidy level. Changes in arginine decarboxylase activity were positively correlated to the polyamine levels, which suggest that the later is a key factor in regulating the polyamine levels during somatic embryogenesis in citrus plants.

Convergent occurrence of the developmental hourglass in plant and animal embryogenesis?

PubMed

Cridge, Andrew G; Dearden, Peter K; Brownfield, Lynette R

2016-04-01

The remarkable similarity of animal embryos at particular stages of development led to the proposal of a developmental hourglass. In this model, early events in development are less conserved across species but lead to a highly conserved 'phylotypic period'. Beyond this stage, the model suggests that development once again becomes less conserved, leading to the diversity of forms. Recent comparative studies of gene expression in animal groups have provided strong support for the hourglass model. How and why might such an hourglass pattern be generated? More importantly, how might early acting events in development evolve while still maintaining a later conserved stage? The discovery that an hourglass pattern may also exist in the embryogenesis of plants provides comparative data that may help us explain this phenomenon. Whether the developmental hourglass occurs in plants, and what this means for our understanding of embryogenesis in plants and animals is discussed. Models by which conserved early-acting genes might change their functional role in the evolution of gene networks, how networks buffer these changes, and how that might constrain, or confer diversity, of the body plan are also discused. Evidence of a morphological and molecular hourglass in plant and animal embryogenesis suggests convergent evolution. This convergence is likely due to developmental constraints imposed upon embryogenesis by the need to produce a viable embryo with an established body plan, controlled by the architecture of the underlying gene regulatory networks. As the body plan is largely laid down during the middle phases of embryo development in plants and animals, then it is perhaps not surprising this stage represents the narrow waist of the hourglass where the gene regulatory networks are the oldest and most robust and integrated, limiting species diversity and constraining morphological space. © The Author 2016. Published by Oxford University Press on behalf of the Annals of

Influence of Abscisic Acid and Sucrose on Somatic Embryogenesis in Cactus Copiapoa tenuissima Ritt. forma mostruosa

PubMed Central

Lema-Rumińska, J.; Goncerzewicz, K.; Gabriel, M.

2013-01-01

Having produced the embryos of cactus Copiapoa tenuissima Ritt. forma monstruosa at the globular stage and callus, we investigated the effect of abscisic acid (ABA) in the following concentrations: 0, 0.1, 1, 10, and 100 μM on successive stages of direct (DSE) and indirect somatic embryogenesis (ISE). In the indirect somatic embryogenesis process we also investigated a combined effect of ABA (0, 0.1, 1 μM) and sucrose (1, 3, 5%). The results showed that a low concentration of ABA (0-1 μM) stimulates the elongation of embryos at the globular stage and the number of correct embryos in direct somatic embryogenesis, while a high ABA concentration (10–100 μM) results in growth inhibition and turgor pressure loss of somatic embryos. The indirect somatic embryogenesis study in this cactus suggests that lower ABA concentrations enhance the increase in calli fresh weight, while a high concentration of 10 μM ABA or more changes calli color and decreases its proliferation rate. However, in the case of indirect somatic embryogenesis, ABA had no effect on the number of somatic embryos and their maturation. Nevertheless, we found a positive effect of sucrose concentration for both the number of somatic embryos and the increase in calli fresh weight. PMID:23843737

Recent and Late Holocene Alaskan Lake Changes Identified from Water Isotopes

NASA Astrophysics Data System (ADS)

Anderson, L.; Birks, S. J.; Rover, J.; Guldager, N.

2014-12-01

To identify the existence and cause of recent lake area changes in the Yukon Flats, a region of discontinuous permafrost in north central Alaska, we evaluate lake water isotope compositions with remotely sensed imagery and hydroclimatic parameters. Estimates of the ratio of water lost by evaporation to that gained by inflow (E/I) were derived from an isotope-based water balance model. The isotope labels are also used to identify the dominant sources for lakes such as rainfall and snowfall, groundwater, rivers, or thawed permafrost. These parameters are then used in conjunction with climatic data and remotely sensed imagery to identify the patterns and causes of recent lake area changes and for evaluation with lake sediment oxygen isotope records of late Holocene lake water isotope variations. Lake water isotope samples from 83 lakes were acquired in July, August or September between 2007 and 2010 by fixed wing aircraft. An additional set of smaller lakes (n = 33) was sampled by helicopter in September 2009. In July 2011 59 lakes were sampled on foot within five distinct 11.2-km2 areas. River water data used here are previously collected during the months of June through October between 2006 and 2008. Isotope compositions indicate that mixtures of precipitation, river water, and groundwater source ~95% of the studied lakes. The remaining minority are more dominantly sourced by snowmelt and/or permafrost thaw. Isotope-based water balance estimates indicate 58% of lakes lose more than half of inflow by evaporation. For 26% of the lakes studied, evaporative losses exceeded supply. Surface area trend analysis indicates that most lakes were near their maximum extent in the early 1980s during a relatively cool and wet period. Subsequent reductions can be explained by moisture deficits and greater evaporation. Comparison with late Holocene isotope values and trends indicates recent changes are within the range of late Holocene variability. The records indicate a drier and

Comparative transcript profiling by SuperSAGE identifies novel candidate genes for controlling potato quantitative resistance to late blight not compromised by late maturity.

PubMed

Draffehn, Astrid M; Li, Li; Krezdorn, Nicolas; Ding, Jia; Lübeck, Jens; Strahwald, Josef; Muktar, Meki S; Walkemeier, Birgit; Rotter, Björn; Gebhardt, Christiane

2013-01-01

Resistance to pathogens is essential for survival of wild and cultivated plants. Pathogen susceptibility causes major losses of crop yield and quality. Durable field resistance combined with high yield and other superior agronomic characters are therefore, important objectives in every crop breeding program. Precision and efficacy of resistance breeding can be enhanced by molecular diagnostic tools, which result from knowledge of the molecular basis of resistance and susceptibility. Breeding uses resistance conferred by single R genes and polygenic quantitative resistance. The latter is partial but considered more durable. Molecular mechanisms of plant pathogen interactions are elucidated mainly in experimental systems involving single R genes, whereas most genes important for quantitative resistance in crops like potato are unknown. Quantitative resistance of potato to Phytophthora infestans causing late blight is often compromised by late plant maturity, a negative agronomic character. Our objective was to identify candidate genes for quantitative resistance to late blight not compromised by late plant maturity. We used diagnostic DNA-markers to select plants with different field levels of maturity corrected resistance (MCR) to late blight and compared their leaf transcriptomes before and after infection with P. infestans using SuperSAGE (serial analysis of gene expression) technology and next generation sequencing. We identified 2034 transcripts up or down regulated upon infection, including a homolog of the kiwi fruit allergen kiwellin. 806 transcripts showed differential expression between groups of genotypes with contrasting MCR levels. The observed expression patterns suggest that MCR is in part controlled by differential transcript levels in uninfected plants. Functional annotation suggests that, besides biotic and abiotic stress responses, general cellular processes such as photosynthesis, protein biosynthesis, and degradation play a role in MCR.

Dynamics of post-translationally modified histones during barley pollen embryogenesis in the presence or absence of the epi-drug trichostatin A.

PubMed

Pandey, Pooja; Daghma, Diaa S; Houben, Andreas; Kumlehn, Jochen; Melzer, Michael; Rutten, Twan

2017-06-01

Improving pollen embryogenesis. Despite the agro-economic importance of pollen embryogenesis, the mechanisms underlying this process are still poorly understood. We describe the dynamics of chromatin modifications (histones H3K4me2, H3K9ac, H3K9me2, and H3K27me3) and chromatin marks (RNA polymerase II CDC phospho-Ser5, and CENH3) during barley pollen embryogenesis. Immunolabeling results show that, in reaction to stress, immature pollen rapidly starts reorganizing several important chromatin modifications indicative of a change in cell fate. This new chromatin modification pattern was accomplished within 24 h from whereon it remained unaltered during subsequent mitotic activity. This indicates that cell fate transition, the central element of pollen embryogenesis, is completed early on during the induction process. Application of the histone deacetylase inhibitor trichostatin A stimulated pollen embryogenesis when used on pollen with a gametophytic style chromatin pattern. However, when this drug was administered to embryogenic pollen, the chromatin markers reversed toward a gametophytic profile, embryogenesis was halted and all pollen invariably died.

Effects of High Magneto-Gravitational Environment on Silkworm Embryogenesis

NASA Astrophysics Data System (ADS)

Tian, Zongcheng; Li, Muwang; Qian, Airong; Xu, Huiyun; Wang, Zhe; Di, Shengmeng; Yang, Pengfei; Hu, Lifang; Ding, Chong; Zhang, Wei; Luo, Mingzhi; Han, Jing; Gao, Xiang; Huang, Yongping; Shang, Peng

2010-04-01

The objective of this research was to observe whether silkworm embryos can survive in a high magneto-gravitational environment (HMGE) and what significant phenotype changes can be produced. The hatching rate, hatching time, life span, growth velocity and cocoon weight of silkworm were measured after silkworm embryos were exposed to HMGE (0 g, 12 T; 1 g, 16 T; and 2 g, 12 T) for a period of time. Compared with the control group, 0 g exposure resulted in a lower hatching rate and a shorter life span. Statistically insignificant morphological changes had been observed for larvae growth velocity, incidence of abnormal markings and weight of cocoons. These results suggest that the effect of HMGE on silkworm embryogenesis is not lethal. Bio-effects of silkworm embryogenesis at 0 g in a HMGE were similar with those of space flight. The hatching time, life span and hatching rates of silkworm may be potential phenotype markers related to exposure in a weightless environment.

Studies for Somatic Embryogenesis in Sweet Potato

NASA Technical Reports Server (NTRS)

Bennett, J. Rasheed; Prakash, C. S.

1997-01-01

The purpose of this study was to improve the somatic embryo (SE) system for plant production of sweet potato (Ipomoea batatas L(Lam)). Explants isolated from SE-derived sweet potato plants were compared with control (non SE-derived) plants for their competency for SE production. Leaf explants were cultured on Murashige-Skoog (MS) medium with 2,4-dichlorophenoxy acetic acid (0.2 mg/L) and 6-benzylaminopurine (2.5 mg/L) for 2 weeks in darkness and transferred to MS medium with abscisic acid (2.5 mg/L). Explants isolated from those plants developed through somatic embryogenesis produced new somatic embryos rapidly and in higher frequency than those isolated from control plants They also appeared to grow faster in tissue culture than the control plants. Current studies in the laboratory are examining whether plants derived from a cyclical embryogenesis system (five cycles) would have any further positive impact on the rapidity and frequency of somatic embryo development. More detailed studies using electron microscopy are expected to show the point of origin of the embryos and to allow determination of their quality throughout the cyclical process. This study may facilitate improved plant micropropagation, gene transfer and germplasm conservation in sweet potato.

Effects of p-chlorophenoxyisobutyric acid, arabinogalactan, and activated charcoal on microspore embryogenesis in kale.

PubMed

Niu, R Q; Zhang, Y; Tong, Y; Liu, Z Y; Wang, Y H; Feng, H

2015-04-27

To improve embryogenesis in microspore cultures of kale (Brassica oleracea L. var. acephala DC.), 6-benzylaminopurine (6-BA), naphthaleneacetic acid (NAA), arabinogalactan (AG), p-chlorophenoxyisobutyric acid (PCIB), and activated charcoal (AC) were added to the medium using four varieties of kale. The results showed that the addition of AG (0.1-0.2 g/L), AC (0.1-0.2 g/L) or a combination of 6-BA (0.1-0.2 mg/L) and NAA (0.1-0.2 mg/L) promoted embryo-genesis. Adding 40 μM PCIB or a combination of 40 μM PCIB and 0.2 g/L AC to NLN-13 medium at pH 5.8 effectively enhanced embryogenesis. Treatment with a combination of 40 μM PCIB and 10 mg/L AG gave the highest rate of embryonic induction, especially in genotype "Y007," which showed a twelve-fold increase in yield.

The importance of SERINE DECARBOXYLASE1 (SDC1) and ethanolamine biosynthesis during embryogenesis of Arabidopsis thaliana.

PubMed

Yunus, Ian Sofian; Liu, Yu-Chi; Nakamura, Yuki

2016-11-01

In plants, ethanolamine is considered a precursor for the synthesis of choline, which is an essential dietary nutrient for animals. An enzyme serine decarboxylase (SDC) has been identified and characterized in Arabidopsis, which directly converts serine to ethanolamine, a precursor to phosphorylethanolamine and its subsequent metabolites in plants. However, the importance of SDC and ethanolamine production in plant growth and development remains unclear. Here, we show that SDC is required for ethanolamine biosynthesis in vivo and essential in plant embryogenesis in Arabidopsis. The knockout of SDC1 caused an embryonic lethal defect due to the developmental arrest of the embryos at the heart stage. During embryo development, the expression was observed at the later stages, at which developmental defect occurred in the knockout mutant. Overexpression of SDC1 in planta increased levels of ethanolamine, phosphatidylethanolamine, and phosphatidylcholine both in leaves and siliques. These results suggest that SDC1 plays an essential role in ethanolamine biosynthesis during the embryogenesis in Arabidopsis. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Tobacco arabinogalactan protein NtEPc can promote banana (Musa AAA) somatic embryogenesis.

PubMed

Shu, H; Xu, L; Li, Z; Li, J; Jin, Z; Chang, S

2014-12-01

Banana is an important tropical fruit worldwide. Parthenocarpy and female sterility made it impossible to improve banana varieties through common hybridization. Genetic transformation for banana improvement is imperative. But the low rate that banana embryogenic callus was induced made the transformation cannot be performed in many laboratories. Finding ways to promote banana somatic embryogenesis is critical for banana genetic transformation. After tobacco arabinogalactan protein gene NtEPc was transformed into Escherichia coli (DE3), the recombinant protein was purified and filter-sterilized. A series of the sterilized protein was added into tissue culture medium. It was found that the number of banana immature male flowers developing embryogenic calli increased significantly in the presence of NtEPc protein compared with the effect of the control medium. Among the treatments, explants cultured on medium containing 10 mg/l of NtEPc protein had the highest chance to develop embryogenic calli. The percentage of lines that developed embryogenic calli on this medium was about 12.5 %. These demonstrated that NtEPc protein can be used to promote banana embryogenesis. This is the first paper that reported that foreign arabinogalactan protein (AGP) could be used to improve banana somatic embryogenesis.

Rosmarinic acid plays a protective role in the embryogenesis of zebrafish exposed to food colours through its influence on aurora kinase A level.

PubMed

Swarnalatha, Y; Jerrine Joseph, I S; Jayakrishna, Tippabathani

2017-05-01

To evaluate the protective nature of the rosmarinic acid from Sphaeranthus amaranthoides during zebra fish embryogenesis. Rosmarinic acid was isolated from the S. amaranthoides. An accurate, sensitive and simple LC-MS analysis was performed to determine the rosmarinic acid from S. amaranthoides. In the present study, zebrafish embryos were exposed to crimson red and sunset yellow at a concentration of 0.1 and 0.5mg/l and the effect of these food colours on the levels of aurora kinase A was studied individually. Aurora kinase A levels are crucial for embryogenesis in zebrafish which is used as model in this study. The decrease of aurora kinase A levels in food colour treated embryos influences the embryogenesis, resulting in short and bent trunk leading to cell death and growth retardation. Elevated levels of aurora kinase A in rosmarinic acid treated groups can be attributed to the restoration of normal growth in zebra fish embryos with well developed brain and eyes. Further insilico docking studies were carried out and target was identified as rosmarinic acid. From the docking studies the docking poses and binding energy confirms that aurora kinase A is the target for rosmarinic acid. Rosmarinic acid was found to play a protective role in the embryogenesis of zebra fish exposed to food colours (crimson red and sunset yellow) through its influence on aurora kinase A levels. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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

PubMed

Nair, R Ramakrishnan; Dutta Gupta, S

2006-01-01

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

Apo-14 is required for digestive system organogenesis during fish embryogenesis and larval development.

PubMed

Xia, Jian-Hong; Liu, Jing-Xia; Zhou, Li; Li, Zhi; Gui, Jian-Fang

2008-01-01

Apo-14 is a fish-specific apolipoprotein and its biological function remains unknown. In this study, CagApo-14 was cloned from gibel carp (Carassius auratus gibelio) and its expression pattern was investigated during embryogenesis and early larval development. The CagApo-14 transcript and its protein product were firstly localized in the yolk syncytial layer at a high level during embryogenesis, and then found to be restricted to the digestive system including liver and intestine in later embryos and early larvae. Immunofluorescence staining in larvae and adults indicated that Cag Apo-14 protein was predominantly synthesized in and excreted from sinusoidal endothelial cells of liver tissue. Morpholino knockdown of Cag Apo-14 resulted in severe disruption of digestive organs including liver, intestine, pancreas and swim bladder. Moreover, yolk lipid transportation and utilization were severely affected in the Cag Apo-14 morphants. Overall, this data indicates that Cag Apo-14 is required for digestive system organogenesis during fish embryogenesis and larval development.

Copb2 is essential for embryogenesis and hypomorphic mutations cause human microcephaly.

PubMed

DiStasio, Andrew; Driver, Ashley; Sund, Kristen; Donlin, Milene; Muraleedharan, Ranjith M; Pooya, Shabnam; Kline-Fath, Beth; Kaufman, Kenneth M; Prows, Cynthia A; Schorry, Elizabeth; Dasgupta, Biplab; Stottmann, Rolf W

2017-12-15

Primary microcephaly is a congenital brain malformation characterized by a head circumference less than three standard deviations below the mean for age and sex and results in moderate to severe mental deficiencies and decreased lifespan. We recently studied two children with primary microcephaly in an otherwise unaffected family. Exome sequencing identified an autosomal recessive mutation leading to an amino acid substitution in a WD40 domain of the highly conserved Coatomer Protein Complex, Subunit Beta 2 (COPB2). To study the role of Copb2 in neural development, we utilized genome-editing technology to generate an allelic series in the mouse. Two independent null alleles revealed that Copb2 is essential for early stages of embryogenesis. Mice homozygous for the patient variant (Copb2R254C/R254C) appear to have a grossly normal phenotype, likely due to differences in corticogenesis between the two species. Strikingly, mice heterozygous for the patient mutation and a null allele (Copb2R254C/Zfn) show a severe perinatal phenotype including low neonatal weight, significantly increased apoptosis in the brain, and death within the first week of life. Immunostaining of the Copb2R254C/Zfnbrain revealed a reduction in layer V (CTIP2+) neurons, while the overall cell density of the cortex is unchanged. Moreover, neurospheres derived from animals with Copb2 variants grew less than control. These results identify a general requirement for COPB2 in embryogenesis and a specific role in corticogenesis. We further demonstrate the utility of CRISPR-Cas9 generated mouse models in the study of potential pathogenicity of variants of potential clinical interest. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Yield performance of cacao propagated by somatic embryogenesis and grafting

USDA-ARS?s Scientific Manuscript database

Twelve cacao (Theobroma cacao) clones propagated by grafting and somatic embryogenesis and grown on an Ultisol soil were evaluated for five years under intensive management at Corozal, Puerto Rico. Preliminary data showed no significant differences between propagation methods for yield of dry beans ...

Rapid quantification of neutral lipids and triglycerides during zebrafish embryogenesis.

PubMed

Yoganantharjah, Prusothman; Byreddy, Avinesh R; Fraher, Daniel; Puri, Munish; Gibert, Yann

2017-01-01

The zebrafish is a useful vertebrate model to study lipid metabolism. Oil Red-O (ORO) staining of zebrafish embryos, though sufficient for visualizing the localization of triglycerides, was previously inadequate to quantify neutral lipid abundance. For metabolic studies, it is crucial to be able to quantify lipids during embryogenesis. Currently no cost effective, rapid and reliable method exists to quantify the deposition of neutral lipids and triglycerides. Thin layer chromatography (TLC), gas chromatography and mass spectrometry can be used to accurately measure lipid levels, but are time consuming and costly in their use. Hence, we developed a rapid and reliable method to quantify neutral lipids and triglycerides. Zebrafish embryos were exposed to Rimonabant (Rimo) or WIN 55,212-2 mesylate (WIN), compounds previously shown to modify lipid content during zebrafish embryogenesis. Following this, ORO stain was extracted out of both the zebrafish body and yolk sac and optical density was measured to give an indication of neutral lipid and triglyceride accumulation. Embryos treated with 0.3 microM WIN resulted in increased lipid accumulation, whereas 3 microM Rimo caused a decrease in lipid accumulation during embryogenesis. TLC was performed on zebrafish bodies to validate the developed method. In addition, BODIPY free fatty acids were injected into zebrafish embryos to confirm quantification of changes in lipid content in the embryo. Previously, ORO was limited to qualitative assessment; now ORO can be used as a quantitative tool to directly determine changes in the levels of neutral lipids and triglycerides.

The mouse homeobox gene, S8, is expressed during embryogenesis predominantly in mesenchyme.

PubMed

Opstelten, D J; Vogels, R; Robert, B; Kalkhoven, E; Zwartkruis, F; de Laaf, L; Destrée, O H; Deschamps, J; Lawson, K A; Meijlink, F

1991-03-01

The murine S8 gene, originally identified by Kongsuwan et al. [EMBO J. 7(1988)2131-2138] encodes a homeodomain which resembles those of the paired family. We studied the expression pattern during mid-gestation embryogenesis of S8 by in situ hybridization. Expression was detected locally in craniofacial mesenchyme, in the limb, the heart and the somites and sclerotomes all along the axis, and was absent from the central and peripheral nervous system, splanchnopleure, and endodermal derivatives. This pattern differs considerably from that of most previously described homeobox containing genes. By genetic analysis, the gene was located on chromosome 2, about 20 cM from the HOX-4 cluster.

De novo DNA methylation during monkey pre-implantation embryogenesis.

PubMed

Gao, Fei; Niu, Yuyu; Sun, Yi Eve; Lu, Hanlin; Chen, Yongchang; Li, Siguang; Kang, Yu; Luo, Yuping; Si, Chenyang; Yu, Juehua; Li, Chang; Sun, Nianqin; Si, Wei; Wang, Hong; Ji, Weizhi; Tan, Tao

2017-04-01

Critical epigenetic regulation of primate embryogenesis entails DNA methylome changes. Here we report genome-wide composition, patterning, and stage-specific dynamics of DNA methylation in pre-implantation rhesus monkey embryos as well as male and female gametes studied using an optimized tagmentation-based whole-genome bisulfite sequencing method. We show that upon fertilization, both paternal and maternal genomes undergo active DNA demethylation, and genome-wide de novo DNA methylation is also initiated in the same period. By the 8-cell stage, remethylation becomes more pronounced than demethylation, resulting in an increase in global DNA methylation. Promoters of genes associated with oxidative phosphorylation are preferentially remethylated at the 8-cell stage, suggesting that this mode of energy metabolism may not be favored. Unlike in rodents, X chromosome inactivation is not observed during monkey pre-implantation development. Our study provides the first comprehensive illustration of the 'wax and wane' phases of DNA methylation dynamics. Most importantly, our DNA methyltransferase loss-of-function analysis indicates that DNA methylation influences early monkey embryogenesis.

De novo DNA methylation during monkey pre-implantation embryogenesis

PubMed Central

Gao, Fei; Niu, Yuyu; Sun, Yi Eve; Lu, Hanlin; Chen, Yongchang; Li, Siguang; Kang, Yu; Luo, Yuping; Si, Chenyang; Yu, Juehua; Li, Chang; Sun, Nianqin; Si, Wei; Wang, Hong; Ji, Weizhi; Tan, Tao

2017-01-01

Critical epigenetic regulation of primate embryogenesis entails DNA methylome changes. Here we report genome-wide composition, patterning, and stage-specific dynamics of DNA methylation in pre-implantation rhesus monkey embryos as well as male and female gametes studied using an optimized tagmentation-based whole-genome bisulfite sequencing method. We show that upon fertilization, both paternal and maternal genomes undergo active DNA demethylation, and genome-wide de novo DNA methylation is also initiated in the same period. By the 8-cell stage, remethylation becomes more pronounced than demethylation, resulting in an increase in global DNA methylation. Promoters of genes associated with oxidative phosphorylation are preferentially remethylated at the 8-cell stage, suggesting that this mode of energy metabolism may not be favored. Unlike in rodents, X chromosome inactivation is not observed during monkey pre-implantation development. Our study provides the first comprehensive illustration of the 'wax and wane' phases of DNA methylation dynamics. Most importantly, our DNA methyltransferase loss-of-function analysis indicates that DNA methylation influences early monkey embryogenesis. PMID:28233770

Analysis of genetic stability at SSR loci during somatic embryogenesis in maritime pine (Pinus pinaster).

PubMed

Marum, Liliana; Rocheta, Margarida; Maroco, João; Oliveira, M Margarida; Miguel, Célia

2009-04-01

Somatic embryogenesis (SE) is a propagation tool of particular interest for accelerating the deployment of new high-performance planting stock in multivarietal forestry. However, genetic conformity in in vitro propagated plants should be assessed as early as possible, especially in long-living trees such as conifers. The main objective of this work was to study such conformity based on genetic stability at simple sequence repeat (SSR) loci during somatic embryogenesis in maritime pine (Pinus pinaster Ait.). Embryogenic cell lines (ECLs) subjected to tissue proliferation during 6, 14 or 22 months, as well as emblings regenerated from several ECLs, were analyzed. Genetic variation at seven SSR loci was detected in ECLs under proliferation conditions for all time points, and in 5 out of 52 emblings recovered from somatic embryos. Three of these five emblings showed an abnormal phenotype consisting mainly of plagiotropism and loss of apical dominance. Despite the variation found in somatic embryogenesis-derived plant material, no correlation was established between genetic stability at the analyzed loci and abnormal embling phenotype, present in 64% of the emblings. The use of microsatellites in this work was efficient for monitoring mutation events during the somatic embryogenesis in P. pinaster. These molecular markers should be useful in the implementation of new breeding and deployment strategies for improved trees using SE.

Evolution of early embryogenesis in rhabditid nematodes

PubMed Central

Brauchle, Michael; Kiontke, Karin; MacMenamin, Philip; Fitch, David H. A.; Piano, Fabio

2009-01-01

The cell biological events that guide early embryonic development occur with great precision within species but can be quite diverse across species. How these cellular processes evolve and which molecular components underlie evolutionary changes is poorly understood. To begin to address these questions, we systematically investigated early embryogenesis, from the one- to the four-cell embryo, in 34 nematode species related to C. elegans. We found 40 cell-biological characters that captured the phenotypic differences between these species. By tracing the evolutionary changes on a molecular phylogeny, we found that these characters evolved multiple times and independently of one another. Strikingly, all these phenotypes are mimicked by single-gene RNAi experiments in C. elegans. We use these comparisons to hypothesize the molecular mechanisms underlying the evolutionary changes. For example, we predict that a cell polarity module was altered during the evolution of the Protorhabditis group and show that PAR-1, a kinase localized asymmetrically in C. elegans early embryos, is symmetrically localized in the one-cell stage of Protorhabditis group species. Our genome-wide approach identifies candidate molecules—and thereby modules—associated with evolutionary changes in cell-biological phenotypes. PMID:19643102

Custos controls β-catenin to regulate head development during vertebrate embryogenesis.

PubMed

Komiya, Yuko; Mandrekar, Noopur; Sato, Akira; Dawid, Igor B; Habas, Raymond

2014-09-09

Precise control of the canonical Wnt pathway is crucial in embryogenesis and all stages of life, and dysregulation of this pathway is implicated in many human diseases including cancers and birth defect disorders. A key aspect of canonical Wnt signaling is the cytoplasmic to nuclear translocation of β-catenin, a process that remains incompletely understood. Here we report the identification of a previously undescribed component of the canonical Wnt signaling pathway termed Custos, originally isolated as a Dishevelled-interacting protein. Custos contains casein kinase phosphorylation sites and nuclear localization sequences. In Xenopus, custos mRNA is expressed maternally and then widely throughout embryogenesis. Depletion or overexpression of Custos produced defective anterior head structures by inhibiting the formation of the Spemann-Mangold organizer. In addition, Custos expression blocked secondary axis induction by positive signaling components of the canonical Wnt pathway and inhibited β-catenin/TCF-dependent transcription. Custos binds to β-catenin in a Wnt responsive manner without affecting its stability, but rather modulates the cytoplasmic to nuclear translocation of β-catenin. This effect on nuclear import appears to be the mechanism by which Custos inhibits canonical Wnt signaling. The function of Custos is conserved as loss-of-function and gain-of-function studies in zebrafish also demonstrate a role for Custos in anterior head development. Our studies suggest a role for Custos in fine-tuning canonical Wnt signal transduction during embryogenesis, adding an additional layer of regulatory control in the Wnt-β-catenin signal transduction cascade.

Expression of the homeotic gene mab-5 during Caenorhabditis elegans embryogenesis.

PubMed

Cowing, D W; Kenyon, C

1992-10-01

mab-5 is a member of a complex of homeobox-containing genes evolutionarily related to the Antennapedia and bithorax complexes of Drosophila melanogaster. Like the homeotic genes in Drosophila, mab-5 is required in a particular region along the anterior-posterior body axis, and acts during postembryonic development to give cells in this region their characteristic identities. We have used a mab-5-lacZ fusion integrated into the C. elegans genome to study the posterior-specific expression of mab-5 during embryogenesis. The mab-5-lacZ fusion was expressed in the posterior of the embryo by 180 minutes after the first cleavage, indicating that the mechanisms responsible for the position-specific expression of mab-5-lacZ act at a relatively early stage of embryogenesis. In embryos homozygous for mutations in the par genes, which disrupt segregation of factors during early cleavages, expression of mab-5-lacZ was no longer localized to the posterior. This suggests that posterior-specific expression of mab-5 depends on the appropriate segregation of developmental factors during early embryogenesis. After extrusion of any blastomere of the four-cell embryo, descendants of the remaining three cells could still express the mab-5-lacZ fusion. In these partial embryos, however, the fusion was often expressed in cells scattered throughout the embryo, suggesting that cell-cell interactions and/or proper positioning of early blastomeres are required for mab-5 expression to be localized to the posterior.

The Arabidopsis USL1 controls multiple aspects of development by affecting late endosome morphology.

PubMed

Yuan, Rongrong; Lan, Jingqiu; Fang, Yuxing; Yu, Hao; Zhang, Jinzhe; Huang, Jiaying; Qin, Genji

2018-06-13

The polar transport of auxin controls many aspects of plant development. However, the molecular mechanisms underlying auxin tranport regulation remain to be further elucidated. We identified a mutant named as usl1 (unflattened and small leaves) in a genetic screen in Arabidopsis thaliana. The usl1 displayed multiple aspects of developmental defects in leaves, embryogenesis, cotyledons, silique phyllotaxy and lateral roots in addition to abnormal leaves. USL1 encodes a protein orthologous to the yeast vacuolar protein sorting (Vps) 38p and human UV RADIATION RESISTANCE-ASSOCIATED GENE (UVRAG). Cell biology, Co-IP/MS and yeast two-hybrid were used to identify the function of USL1. USL1 colocalizes at the subcellular level with VPS29, a key factor of the retromer complex that controls auxin transport. The morphology of the VPS29-associated late endosomes (LE) is altered from small dots in the wild-type to aberrant enlarged circles in the usl1 mutants. The usl1 mutant synergistically interacts with vps29. We also found that USL1 forms a complex with AtVPS30 and AtVPS34. We propose that USL1 controls multiple aspects of plant development by affecting late endosome morphology and by regulating the PIN1 polarity. Our findings provide a new layer of the understanding on the mechanisms of plant development regulation. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Telomere length regulation during cloning, embryogenesis and ageing.

PubMed

Schaetzlein, S; Rudolph, K L

2005-01-01

Telomeres are nucleoprotein complexes at the end of eukaryotic chromosomes with an essential role in chromosome capping. Owing to the end-replication problem of DNA polymerase, telomeres shorten during each cell division. When telomeres become critically short, they loose their capping function, which in turn induces a DNA damage-like response. This mechanism inhibits cell proliferation at the senescence stage and there is evidence that it limits the regenerative capacity of tissues and organs during chronic diseases and ageing. The holoenzyme telomerase synthesises telomeric DNA de novo, but, in humans, it is active only during embryogenesis, in immature germ cells and in a subset of stem/progenitor cells during postnatal life. Telomere length can be maintained or increased by telomerase, a process that appears to be regulated by a variety of telomere-binding proteins that control telomerase recruitment and activity at the telomeres. During embryogenesis, telomerase is strongly activated at the morula/blastocyst transition. At this transition, telomeres are significantly elongated in murine and bovine embryos. Early embryonic telomere elongation is telomerase dependent and leads to a rejuvenation of telomeres in cloned bovine embryos. Understanding of the molecular mechanisms underlying this early embryonic telomere elongation programme is of great interest for medical research in the fields of regeneration, cell therapies and therapeutic cloning.

(Why) Does Evolution Favour Embryogenesis?

PubMed

Rensing, Stefan A

2016-07-01

Complex multicellular organisms typically possess life cycles in which zygotes (formed by gamete fusion) and meiosis occur. Canonical animal embryogenesis describes development from zygote to birth. It involves polarisation of the egg/zygote, asymmetric cell divisions, establishment of axes, symmetry breaking, formation of organs, and parental nutrition (at least in early stages). Similar developmental patterns have independently evolved in other eukaryotic lineages, including land plants and brown algae. The question arises whether embryo-like structures and associated developmental processes recurrently emerge because they are local optima of the evolutionary landscape. To understand which evolutionary principles govern complex multicellularity, we need to analyse why and how similar processes evolve convergently - von Baer's and Haeckel's phylotypic stage revisited in other phyla. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced somatic embryogenesis in Theobroma cacao using the homologous BABY BOOM transcription factor.

PubMed

Florez, Sergio L; Erwin, Rachel L; Maximova, Siela N; Guiltinan, Mark J; Curtis, Wayne R

2015-05-16

Theobroma cacao, the chocolate tree, is an important economic crop in East Africa, South East Asia, and South and Central America. Propagation of elite varieties has been achieved through somatic embryogenesis (SE) but low efficiencies and genotype dependence still presents a significant limitation for its propagation at commercial scales. Manipulation of transcription factors has been used to enhance the formation of SEs in several other plant species. This work describes the use of the transcription factor Baby Boom (BBM) to promote the transition of somatic cacao cells from the vegetative to embryonic state. An ortholog of the Arabidopsis thaliana BBM gene (AtBBM) was characterized in T. cacao (TcBBM). TcBBM expression was observed throughout embryo development and was expressed at higher levels during SE as compared to zygotic embryogenesis (ZE). TcBBM overexpression in A. thaliana and T. cacao led to phenotypes associated with SE that did not require exogenous hormones. While transient ectopic expression of TcBBM provided only moderate enhancements in embryogenic potential, constitutive overexpression dramatically increased SE proliferation but also appeared to inhibit subsequent development. Our work provides validation that TcBBM is an ortholog to AtBBM and has a specific role in both somatic and zygotic embryogenesis. Furthermore, our studies revealed that TcBBM transcript levels could serve as a biomarker for embryogenesis in cacao tissue. Results from transient expression of TcBBM provide confirmation that transcription factors can be used to enhance SE without compromising plant development and avoiding GMO plant production. This strategy could compliment a hormone-based method of reprogramming somatic cells and lead to more precise manipulation of SE at the regulatory level of transcription factors. The technology would benefit the propagation of elite varieties with low regeneration potential as well as the production of transgenic plants, which

Genetic Regulatory Networks in Embryogenesis and Evolution

NASA Technical Reports Server (NTRS)

1998-01-01

The article introduces a series of papers that were originally presented at a workshop titled Genetic Regulatory Network in Embryogenesis and Evaluation. Contents include the following: evolution of cleavage programs in relationship to axial specification and body plan evolution, changes in cell lineage specification elucidate evolutionary relations in spiralia, axial patterning in the leech: developmental mechanisms and evolutionary implications, hox genes in arthropod development and evolution, heterochronic genes in development and evolution, a common theme for LIM homeobox gene function across phylogeny, and mechanisms of specification in ascidian embryos.

Identification of QTLs Associated with Callogenesis and Embryogenesis in Oil Palm Using Genetic Linkage Maps Improved with SSR Markers

PubMed Central

Ting, Ngoot-Chin; Jansen, Johannes; Nagappan, Jayanthi; Ishak, Zamzuri; Chin, Cheuk-Weng; Tan, Soon-Guan; Cheah, Suan-Choo; Singh, Rajinder

2013-01-01

Clonal reproduction of oil palm by means of tissue culture is a very inefficient process. Tissue culturability is known to be genotype dependent with some genotypes being more amenable to tissue culture than others. In this study, genetic linkage maps enriched with simple sequence repeat (SSR) markers were developed for dura (ENL48) and pisifera (ML161), the two fruit forms of oil palm, Elaeis guineensis. The SSR markers were mapped onto earlier reported parental maps based on amplified fragment length polymorphism (AFLP) and restriction fragment length polymorphism (RFLP) markers. The new linkage map of ENL48 contains 148 markers (33 AFLPs, 38 RFLPs and 77 SSRs) in 23 linkage groups (LGs), covering a total map length of 798.0 cM. The ML161 map contains 240 markers (50 AFLPs, 71 RFLPs and 119 SSRs) in 24 LGs covering a total of 1,328.1 cM. Using the improved maps, two quantitative trait loci (QTLs) associated with tissue culturability were identified each for callusing rate and embryogenesis rate. A QTL for callogenesis was identified in LGD4b of ENL48 and explained 17.5% of the phenotypic variation. For embryogenesis rate, a QTL was detected on LGP16b in ML161 and explained 20.1% of the variation. This study is the first attempt to identify QTL associated with tissue culture amenity in oil palm which is an important step towards understanding the molecular processes underlying clonal regeneration of oil palm. PMID:23382832

Identification of novel genes potentially involved in somatic embryogenesis in chicory (Cichorium intybus L.)

PubMed Central

2010-01-01

Background In our laboratory we use cultured chicory (Cichorium intybus) explants as a model to investigate cell reactivation and somatic embryogenesis and have produced 2 chicory genotypes (K59, C15) sharing a similar genetic background. K59 is a responsive genotype (embryogenic) capable of undergoing complete cell reactivation i.e. cell de- and re-differentiation leading to somatic embryogenesis (SE), whereas C15 is a non-responsive genotype (non-embryogenic) and is unable to undergo SE. Previous studies [1] showed that the use of the β-D-glucosyl Yariv reagent (β-GlcY) that specifically binds arabinogalactan-proteins (AGPs) blocked somatic embryo production in chicory root explants. This observation indicates that β-GlcY is a useful tool for investigating somatic embryogenesis (SE) in chicory. In addition, a putative AGP (DT212818) encoding gene was previously found to be significantly up-regulated in the embryogenic K59 chicory genotype as compared to the non-embryogenic C15 genotype suggesting that this AGP could be involved in chicory re-differentiation [2]. In order to improve our understanding of the molecular and cellular regulation underlying SE in chicory, we undertook a detailed cytological study of cell reactivation events in K59 and C15 genotypes, and used microarray profiling to compare gene expression in these 2 genotypes. In addition we also used β-GlcY to block SE in order to identify genes potentially involved in this process. Results Microscopy confirmed that only the K59, but not the C15 genotype underwent complete cell reactivation leading to SE formation. β-GlcY-treatment of explants blocked in vitro SE induction, but not cell reactivation, and induced cell wall modifications. Microarray analyses revealed that 78 genes were differentially expressed between induced K59 and C15 genotypes. The expression profiles of 19 genes were modified by β-GlcY-treatment. Eight genes were both differentially expressed between K59 and C15 genotypes

Glycogen Synthase Kinase-3 is involved in glycogen metabolism control and embryogenesis of Rhodnius prolixus.

PubMed

Mury, Flávia B; Lugon, Magda D; DA Fonseca, Rodrigo Nunes; Silva, Jose R; Berni, Mateus; Araujo, Helena M; Fontenele, Marcio Ribeiro; Abreu, Leonardo Araujo DE; Dansa, Marílvia; Braz, Glória; Masuda, Hatisaburo; Logullo, Carlos

2016-10-01

Rhodnius prolixus is a blood-feeding insect that transmits Trypanosoma cruzi and Trypanosoma rangeli to vertebrate hosts. Rhodnius prolixus is also a classical model in insect physiology, and the recent availability of R. prolixus genome has opened new avenues on triatomine research. Glycogen synthase kinase 3 (GSK-3) is classically described as a key enzyme involved in glycogen metabolism, also acting as a downstream component of the Wnt pathway during embryogenesis. GSK-3 has been shown to be highly conserved among several organisms, mainly in the catalytic domain region. Meanwhile, the role of GSK-3 during R. prolixus embryogenesis or glycogen metabolism has not been investigated. Here we show that chemical inhibition of GSK-3 by alsterpaullone, an ATP-competitive inhibitor of GSK3, does not affect adult survival rate, though it alters oviposition and egg hatching. Specific GSK-3 gene silencing by dsRNA injection in adult females showed a similar phenotype. Furthermore, bright field and 4'-6-diamidino-2-phenylindole (DAPI) staining analysis revealed that ovaries and eggs from dsGSK-3 injected females exhibited specific morphological defects. We also demonstrate that glycogen content was inversely related to activity and transcription levels of GSK-3 during embryogenesis. Lastly, after GSK-3 knockdown, we observed changes in the expression of the Wingless (Wnt) downstream target β-catenin as well as in members of other pathways such as the receptor Notch. Taken together, our results show that GSK-3 regulation is essential for R. prolixus oogenesis and embryogenesis.

Synchronization of Somatic Embryogenesis in Date Palm Suspension Culture Using Abscisic Acid.

PubMed

Alwael, Hussain A; Naik, Poornananda M; Al-Khayri, Jameel M

2017-01-01

Somatic embryogenesis is considered the most effective method for commercial propagation of date palm. However, the limitation of obtaining synchronized development of somatic embryos remains an impediment. The synchronization of somatic embryo development is ideal for the applications to produce artificial seeds. Abscisic acid (ABA) is associated with stress response and influences in vitro growth and development. This chapter describes an effective method to achieve synchronized development of somatic embryos in date palm cell suspension culture. Among the ABA concentrations tested (0, 1, 10, 50, 100 μM), the best synchronized growth was obtained in response to 50-100 μM. Here we provide a comprehensive protocol for in vitro plant regeneration of date palm starting with shoot-tip explant, callus initiation and growth, cell suspension establishment, embryogenesis synchronization with ABA treatment, somatic embryo germination, and rooting as well as acclimatized plantlet establishment.

Loss of CMD2‐mediated resistance to cassava mosaic disease in plants regenerated through somatic embryogenesis

PubMed Central

Chauhan, Raj Deepika; Wagaba, Henry; Moll, Theodore; Alicai, Titus; Miano, Douglas; Carrington, James C.; Taylor, Nigel J.

2016-01-01

Summary Cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) are the two most important viral diseases affecting cassava production in Africa. Three sources of resistance are employed to combat CMD: polygenic recessive resistance, termed CMD1, the dominant monogenic type, named CMD2, and the recently characterized CMD3. The farmer‐preferred cultivar TME 204 carries inherent resistance to CMD mediated by CMD2, but is highly susceptible to CBSD. Selected plants of TME 204 produced for RNA interference (RNAi)‐mediated resistance to CBSD were regenerated via somatic embryogenesis and tested in confined field trials in East Africa. Although micropropagated, wild‐type TME 204 plants exhibited the expected levels of resistance, all plants regenerated via somatic embryogenesis were found to be highly susceptible to CMD. Glasshouse studies using infectious clones of East African cassava mosaic virus conclusively demonstrated that the process of somatic embryogenesis used to regenerate cassava caused the resulting plants to become susceptible to CMD. This phenomenon could be replicated in the two additional CMD2‐type varieties TME 3 and TME 7, but the CMD1‐type cultivar TMS 30572 and the CMD3‐type cultivar TMS 98/0505 maintained resistance to CMD after passage through somatic embryogenesis. Data are presented to define the specific tissue culture step at which the loss of CMD resistance occurs and to show that the loss of CMD2‐mediated resistance is maintained across vegetative generations. These findings reveal new aspects of the widely used technique of somatic embryogenesis, and the stability of field‐level resistance in CMD2‐type cultivars presently grown by farmers in East Africa, where CMD pressure is high. PMID:26662210

The embryogenesis of the tick Rhipicephalus (Boophilus) microplus: the establishment of a new chelicerate model system.

PubMed

Santos, Vitória Tobias; Ribeiro, Lupis; Fraga, Amanda; de Barros, Cíntia Monteiro; Campos, Eldo; Moraes, Jorge; Fontenele, Marcio Ribeiro; Araújo, Helena Marcolla; Feitosa, Natalia Martins; Logullo, Carlos; da Fonseca, Rodrigo Nunes

2013-12-01

Chelicerates, which include spiders, ticks, mites, scorpions, and horseshoe crabs, are members of the phylum Arthropoda. In recent years, several molecular experimental studies of chelicerates have examined the embryology of spiders; however, the embryology of other groups, such as ticks (Acari: Parasitiformes), has been largely neglected. Ticks and mites are believed to constitute a monophyletic group, the Acari. Due to their blood-sucking activities, ticks are also known to be vectors of several diseases. In this study, we analyzed the embryonic development of the cattle tick, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). First, we developed an embryonic staging system consisting of 14 embryonic stages. Second, histological analysis and antibody staining unexpectedly revealed the presence of a population of tick cells with similar characteristics to the spider cumulus. Cumulus cell populations also exist in other chelicerates; these cells are responsible for the breaking of radial symmetry through bone morphogenetic protein signaling. Third, it was determined that the posterior (opisthosomal) embryonic region of R. microplus is segmented. Finally, we identified the presence of a transient ventral midline furrow and the formation and regression of a fourth leg pair; these features may be regarded as hallmarks of late tick embryogenesis. Importantly, most of the aforementioned features are absent from mite embryos, suggesting that mites and ticks do not constitute a monophyletic group or that mites have lost these features. Taken together, our findings provide fundamental common ground for improving knowledge regarding tick embryonic development, thereby facilitating the establishment of a new chelicerate model system. Copyright © 2013 Wiley Periodicals, Inc.

Assembly of embryonic and extraembryonic stem cells to mimic embryogenesis in vitro.

PubMed

Harrison, Sarah Ellys; Sozen, Berna; Christodoulou, Neophytos; Kyprianou, Christos; Zernicka-Goetz, Magdalena

2017-04-14

Mammalian embryogenesis requires intricate interactions between embryonic and extraembryonic tissues to orchestrate and coordinate morphogenesis with changes in developmental potential. Here, we combined mouse embryonic stem cells (ESCs) and extraembryonic trophoblast stem cells (TSCs) in a three-dimensional scaffold to generate structures whose morphogenesis is markedly similar to that of natural embryos. By using genetically modified stem cells and specific inhibitors, we show that embryogenesis of ESC- and TSC-derived embryos-ETS-embryos-depends on cross-talk involving Nodal signaling. When ETS-embryos develop, they spontaneously initiate expression of mesoderm and primordial germ cell markers asymmetrically on the embryonic and extraembryonic border, in response to Wnt and BMP signaling. Our study demonstrates the ability of distinct stem cell types to self-assemble in vitro to generate embryos whose morphogenesis, architecture, and constituent cell types resemble those of natural embryos. Copyright © 2017, American Association for the Advancement of Science.

Comparative Developmental Staging of Female and Male Water Fleas Daphnia pulex and Daphnia magna During Embryogenesis.

PubMed

Toyota, Kenji; Hiruta, Chizue; Ogino, Yukiko; Miyagawa, Shinichi; Okamura, Tetsuro; Onishi, Yuta; Tatarazako, Norihisa; Iguchi, Taisen

2016-02-01

The freshwater crustacean genus Daphnia has been used extensively in ecological, developmental and ecotoxicological studies. Daphnids produce only female offspring by parthenogenesis under favorable conditions, but in response to various unfavorable conditions and external stimuli, they produce male offspring. Although we reported that exogenous exposure to juvenile hormones and their analogs can induce male offspring even under female-producing conditions, we recently established a male induction system in the Daphnia pulex WTN6 strain simply by changing day-length. This male and female induction system is suitable for understanding the innate mechanisms of sexual dimorphic development in daphnids. Embryogenesis has been described as a normal plate (developmental staging) in various daphnid species; however, all studies have mainly focused on female development. Here, we describe the developmental staging of both sexes during embryogenesis in two representative daphnids, D. pulex and D. magna, based on microscopic time-course observations. Our findings provide the first detailed insights into male embryogenesis in both species, and contribute to the elucidation of the mechanisms underlying sexual differentiation in daphnids.

The cellular and molecular biology of conifer embryogenesis.

PubMed

Cairney, John; Pullman, Gerald S

2007-01-01

Gymnosperms and angiosperms are thought to have evolved from a common ancestor c. 300 million yr ago. The manner in which gymnosperms and angiosperms form seeds has diverged and, although broad similarities are evident, the anatomy and cell and molecular biology of embryogenesis in gymnosperms, such as the coniferous trees pine, spruce and fir, differ significantly from those in the most widely studied model angiosperm Arabidopsis thaliana. Molecular analysis of signaling pathways and processes such as programmed cell death and embryo maturation indicates that many developmental pathways are conserved between angiosperms and gymnosperms. Recent genomics research reveals that almost 30% of mRNAs found in developing pine embryos are absent from other conifer expressed sequence tag (EST) collections. These data show that the conifer embryo differs markedly from other gymnosperm tissues studied to date in terms of the range of genes transcribed. Approximately 72% of conifer embryo-expressed genes are found in the Arabidopsis proteome and conifer embryos contain mRNAs of very similar sequence to key genes that regulate seed development in Arabidopsis. However, 1388 loblolly pine (Pinus taeda) embryo ESTs (11.4% of the collection) are novel and, to date, have been found in no other plant. The data imply that, in gymnosperm embryogenesis, differences in structure and development are achieved by subtle molecular interactions, control of spatial and temporal gene expression and the regulating agency of a few unique proteins.

In vitro plant regeneration of Aster scaber via somatic embryogenesis.

PubMed

Boo, Kyung Hwan; Cao, Dang Viet; Pamplona, Reniel S; Lee, Doseung; Riu, Key-Zung; Lee, Dong-Sun

2015-01-01

We established an in vitro plant regeneration system via somatic embryogenesis of Aster scaber, an important source of various biologically active phytochemicals. We examined the callus induction and embryogenic capacities of three explants, including leaves, petioles, and roots, on 25 different media containing different combinations of α-naphthalene acetic acid (NAA) and 6-benzyladenine (BA). The optimum concentrations of NAA and BA for the production of embryogenic calli were 5.0 μM and 0.05 μM, respectively. Media containing higher concentrations of auxin and cytokinin (such as 25 μM NAA and 25 μM BA) were suitable for shoot regeneration, especially for leaf-derived calli, which are the most readily available calli and are highly competent. For root induction from regenerated shoots, supplemental auxin and/or cytokinin did not improve rooting, but instead caused unwanted callus induction or retarded growth of regenerated plants. Therefore, plant growth regulator-free medium was preferable for root induction. Normal plants were successfully obtained from calli under the optimized conditions described above. This is the first report of the complete process of in vitro plant regeneration of A. scaber via somatic embryogenesis.

Comparison of somatic embryogenesis in Medicago sativa and Medicago truncatula.

PubMed

Hoori, F; Ehsanpour, A A; Mostajeran, A

2007-02-01

In this study, the regeneration through embryogenesis of two species of Medicago were studied. Seeds of Medicago sativa cv. Rehnani and M. truncatula line A17 were grown on MS medium. After 4-6 weeks, segments of leaf and stem from two species were transferred to MS medium containing 2 mg L(-1) NAA, 2,4-D and Kinetin. The results indicated that callus formation from leaf explants of M. sativa was higher than M. trancatula. In the next stage, media with different combinations of auxin, cytokinin or ethinyl estradiol were provided for regeneration. Then in two stages, explants of leaf and stem of two species were transferred on these media. Results after 3-6 weeks showed that in medium containing NAA and TDZ, stem pieces ofM. sativa produced shoots while leaf pieces on NAA and ethinyl estradiol formed roots. Leaf explants of M. truncatula in the medium containing NAA and BAP, produced somatic embryos. Also in media with auxin and ethinyl estradiol, somatic embryos were formed on calli of two species. Ethinyl estradiol and auxin together can induce somatic embryogenesis and root production on calli and stem or leaf explants.

Arabinogalactan-proteins stimulate somatic embryogenesis and plant propagation of Pelargonium sidoides.

PubMed

Duchow, Stefanie; Dahlke, Renate I; Geske, Thomas; Blaschek, Wolfgang; Classen, Birgit

2016-11-05

Root extracts of the medicinal plant Pelargonium sidoides, native to South Africa, are used globally for the treatment of common cold and cough. Due to an increasing economic commercialization of P. sidoides remedies, wild collections of root material should be accompanied by effective methods for plant propagation like somatic embryogenesis. Based on this, the influence of arabinogalactan-proteins (AGPs) on somatic embryogenesis and plant propagation of P. sidoides has been investigated. High-molecular weight AGPs have been isolated from dried roots as well as from cell cultures of P. sidoides with yields between 0.1% and 0.9%, respectively. AGPs are characterized by a 1,3-linked Galp backbone, branched at C6 to 1,6-linked Galp side chains terminated by Araf and to a minor extent by GlcpA, Galp or Rhap. Treatment of explants of P. sidoides with AGPs from roots or suspension culture over 5.5 weeks resulted in effective stimulation of somatic embryo development and plant regeneration. Copyright © 2016. Published by Elsevier Ltd.

Shoot regeneration and embryogenesis in lily shoot tips cryopreserved by droplet vitrification

USDA-ARS?s Scientific Manuscript database

Shoot regeneration and embryogenesis were, for the first time, achieved directly in shoot tips of Lilium Oriental hybrid ‘Siberia’ following cryopreservation by droplet-vitrification. Shoot tips (2 mm in length) including 2-3 leaf primordia were excised from 4-week-old adventitious shoots directly r...

Transcriptional analysis of late ripening stages of grapevine berry

PubMed Central

2011-01-01

Background The composition of grapevine berry at harvest is a major determinant of wine quality. Optimal oenological maturity of berries is characterized by a high sugar/acidity ratio, high anthocyanin content in the skin, and low astringency. However, harvest time is still mostly determined empirically, based on crude biochemical composition and berry tasting. In this context, it is interesting to identify genes that are expressed/repressed specifically at the late stages of ripening and which may be used as indicators of maturity. Results Whole bunches and berries sorted by density were collected in vineyard on Chardonnay (white cultivar) grapevines for two consecutive years at three stages of ripening (7-days before harvest (TH-7), harvest (TH), and 10-days after harvest (TH+10)). Microvinification and sensory analysis indicate that the quality of the wines made from the whole bunches collected at TH-7, TH and TH+10 differed, TH providing the highest quality wines. In parallel, gene expression was studied with Qiagen/Operon microarrays using two types of samples, i.e. whole bunches and berries sorted by density. Only 12 genes were consistently up- or down-regulated in whole bunches and density sorted berries for the two years studied in Chardonnay. 52 genes were differentially expressed between the TH-7 and TH samples. In order to determine whether these genes followed a similar pattern of expression during the late stages of berry ripening in a red cultivar, nine genes were selected for RT-PCR analysis with Cabernet Sauvignon grown under two different temperature regimes affecting the precocity of ripening. The expression profiles and their relationship to ripening were confirmed in Cabernet Sauvignon for seven genes, encoding a carotenoid cleavage dioxygenase, a galactinol synthase, a late embryogenesis abundant protein, a dirigent-like protein, a histidine kinase receptor, a valencene synthase and a putative S-adenosyl-L-methionine:salicylic acid carboxyl

Somatic embryogenesis in immature cotyledons of Manchurian ash (Fraxinus mandshurica Rupr.)

USDA-ARS?s Scientific Manuscript database

Somatic embryogenesis was obtained from immature cotyledon explants that were cultured on half-strength Murashige and Skoog (MS) salts and vitamins with 5.4 uM naphthaleneacetic acid (NAA) and 0.2 uM thidiazuron (TDZ) plus a 4x4 factorial combination of 0,9.8, 34.6, or 49.2 uM indole-3-butyric acid ...

Exopolyphosphatases in nuclear and mitochondrial fractions during embryogenesis of the hard tick Rhipicephalus (Boophilus) microplus.

PubMed

Campos, Eldo; Façanha, Arnoldo R; Costa, Evenilton P; da Silva Vaz, Itabajara; Masuda, Aoi; Logullo, Carlos

2008-11-01

The present work evaluated polyphosphate (poly P) metabolism in nuclear and mitochondrial fractions during Rhipicephalus microplus embryogenesis. Nuclear poly P decreased and activity of exopolyphosphatase (PPX - polyphosphate-phosphohydrolases; EC 3.6.1.11) increased after embryo cellularization until the end of embryogenesis. The utilization of mitochondrial poly P content occurred between embryo cellularization and segmentation stages. Increasing amounts of total RNA extracted from eggs progressively enhanced nuclear PPX activity, whereas it exerted no effect on mitochondrial PPX activity. The decline in total poly P content after the 7th day of embryogenesis does not reflect the free P(i) increase and the total poly P chain length decrease after embryo cellularization. The Km(app) utilizing poly P(3), poly P(15) and poly P(65) as substrate was almost the same for the nuclear fraction (around 1muM), while the affinity for substrate in mitochondrial fraction was around 10 times higher for poly P(3) (Km(app) = 0.2muM) than for poly P(15) (Km(app) = 2.8muM) and poly P(65) (Km(app) = 3.6muM). PPX activity was stimulated by a factor of two by Mg2+ and Co2+ in the nuclear fraction and only by Mg2+ in the mitochondrial fraction. Heparin (20microg/mL) inhibited nuclear and mitochondrial PPX activity in about 90 and 95% respectively. Together, these data are consistent with the existence of two different PPX isoforms operating in the nuclei and mitochondria of the hard tick R. microplus with distinct metal dependence, inhibitor and activator sensitivities. The data also shed new light on poly P biochemistry during arthropod embryogenesis, opening new routes for future comparative studies on the physiological roles of different poly P pools distributed over cell compartments.

Efficient plant regeneration through somatic embryogenesis from callus cultures of Oncidium (Orchidaceae).

PubMed

Chen, J -T.; Chang, W -C.

2000-12-07

An efficient method was established for high frequency somatic embryogenesis and plant regeneration from callus cultures of a hybrid of sympodial orchid (Oncidium 'Gower Ramsey'). Compact and yellow-white embryogenic calli formed from root tips and cut ends of stem and leaf segments on 1/2 MS [11] basal medium supplemented with 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ, 0.1-3 mg/l), 2,4-dichlorophenoxyacetic acid (2,4-D, 3-10 mg/l) and peptone (1 g/l) for 4-7 weeks. Embryogenic callus was maintained by subculture on the same medium for callus induction and proliferated 2-4 times (fresh weight) in 1 month. Initiation of somatic embryogenesis and development up to the protocorm-like-bodies (PLBs) from callus cultures was achieved on hormone-free basal medium. Regenerants were recovered from somatic embryos (SEs) after transfer to the same medium and showed normal development. The optimized protocol required about 12-14 weeks from the initiation of callus to the plantlet formation. Generally, the frequency of embryo formation of root-derived callus was higher than stem- and leaf-derived calli. Combinations of naphthaleneacetic acid (NAA) and TDZ significantly promoted embryo formation from callus cultures. The high-frequency (93.8%) somatic embryogenesis and an average of 29.1 SEs per callus (3x3 mm(2)) was found in root-derived callus on a basal medium supplemented with 0.1 mg/l NAA and 3 mg/l TDZ. Almost all the SEs converted and the plantlets grew well with an almost 100% survival rate when potted in sphagnum moss and acclimatized in the greenhouse.

Plant regeneration via direct somatic embryogenesis from leaf explants of Tolumnia Louise Elmore 'Elsa'.

PubMed

Shen, Hui-Ju; Chen, Jen-Tsung; Chung, Hsiao-Hang; Chang, Wei-Chin

2018-01-22

Tolumnia genus (equitant Oncidium) is a group of small orchids with vivid flower color. Thousands of hybrids have been registered on Royal Horticulture Society and showed great potential for ornamental plant market. The aim of this study is to establish an efficient method for in vitro propagation. Leaf explants taken from in vitro-grown plants were used to induce direct somatic embryogenesis on a modified 1/2 MS medium supplemented with five kinds of cytokinins, 2iP, BA, kinetin, TDZ and zeatin at 0.3, 1 and 3 mg l -1 in darkness. TDZ at 3 mg l -1 gave the highest percentage of explants with somatic globular embryos after 90 days of culture. It was found that 2,4-D and light regime highly retarded direct somatic embryogenesis and showed 95-100% of explant browning. Histological observations revealed that the leaf cells divided into meristematic cells firstly, followed by somatic proembryos, and then somatic globular embryos. Eventually, somatic embryos developed a bipolar structure with the shoot apical meristem and the root meristem. Scanning electron microscopy observations showed that the direct somatic embryogenesis from leaf explants was asynchronously. The somatic embryos were found on the leaf tip, the adaxial surface and also the mesophyll through a cleft, and it reflected the heterogeneity of the explant. The 90-day-old globular embryos were detached from the parent explants and transferred onto a hormone-free 1/2 MS medium in light condition for about 1 month to obtain 1-cm-height plantlets. After another 3 months for growth, the plantlets were potted with Sphagnum moss and were acclimatized in a shaded greenhouse. After 1 month of culture, the survival rate was 100%. In this report, a protocol for efficient regenerating a Tolumnia orchid, Louise Elmore 'Elsa', was established via direct somatic embryogenesis and might reveal an alternative approach for mass propagation of Tolumnia genus in orchid industry.

Effect of a 1800 MHz electromagnetic field emitted during embryogenesis on chick development and hatchability.

PubMed

Pawlak, K; Nieckarz, Z; Sechman, A; Wojtysiak, D; Bojarski, B; Tombarkiewicz, B

2018-06-01

The level of artificial electromagnetic field (EMF) has steadily increased with the development of human civilization. The developing chicken embryo has been considered a good model to study the effects of EMF on living organisms. The aim of the study was to determine the effect of a 1800 MHz electromagnetic field during embryogenesis on the frequency of chick embryo malformations, morphometric parameters of the heart and liver and concentration of corticosterone in blood plasma, lipid and glycogen content in the liver of newly hatched chicks. A 1800 MHz EMF was found to shorten the duration of embryogenesis (earlier pipping and hatching of chicks) while having no effect on the quantity and quality of chicks and on increasing the incidence of embryo malformations. Exposure of chick embryos to EMF caused decreases in relative heart weight and right ventricle wall thickness. The pipping and hatching of chicks can be accelerated by stressful impact of EMF, which is confirmed by a significant increase in plasma corticosterone concentrations and decrease in fat and glycogen in the liver of chicks exposed during embryogenesis on the electromagnetic field with a frequency of 1800 MHz. © 2018 Blackwell Verlag GmbH.

The BABY BOOM Transcription Factor Activates the LEC1-ABI3-FUS3-LEC2 Network to Induce Somatic Embryogenesis1[OPEN

PubMed Central

Weemen, Mieke

2017-01-01

Somatic embryogenesis is an example of induced cellular totipotency, where embryos develop from vegetative cells rather than from gamete fusion. Somatic embryogenesis can be induced in vitro by exposing explants to growth regulators and/or stress treatments. The BABY BOOM (BBM) and LEAFY COTYLEDON1 (LEC1) and LEC2 transcription factors are key regulators of plant cell totipotency, as ectopic overexpression of either transcription factor induces somatic embryo formation from Arabidopsis (Arabidopsis thaliana) seedlings without exogenous growth regulators or stress treatments. Although LEC and BBM proteins regulate the same developmental process, it is not known whether they function in the same molecular pathway. We show that BBM transcriptionally regulates LEC1 and LEC2, as well as the two other LAFL genes, FUSCA3 (FUS3) and ABSCISIC ACID INSENSITIVE3 (ABI3). LEC2 and ABI3 quantitatively regulate BBM-mediated somatic embryogenesis, while FUS3 and LEC1 are essential for this process. BBM-mediated somatic embryogenesis is dose and context dependent, and the context-dependent phenotypes are associated with differential LAFL expression. We also uncover functional redundancy for somatic embryogenesis among other Arabidopsis BBM-like proteins and show that one of these proteins, PLETHORA2, also regulates LAFL gene expression. Our data place BBM upstream of other major regulators of plant embryo identity and totipotency. PMID:28830937

The role of chromatin modifications in somatic embryogenesis in plants

PubMed Central

De-la-Peña, Clelia; Nic-Can, Geovanny I.; Galaz-Ávalos, Rosa M.; Avilez-Montalvo, Randy; Loyola-Vargas, Víctor M.

2015-01-01

Somatic embryogenesis (SE) is a powerful tool for plant genetic improvement when used in combination with traditional agricultural techniques, and it is also an important technique to understand the different processes that occur during the development of plant embryogenesis. SE onset depends on a complex network of interactions among plant growth regulators, mainly auxins and cytokinins, during the proembryogenic early stages, and ethylene and gibberellic and abscisic acids later in the development of the somatic embryos. These growth regulators control spatial and temporal regulation of multiple genes in order to initiate change in the genetic program of somatic cells, as well as moderating the transition between embryo developmental stages. In recent years, epigenetic mechanisms have emerged as critical factors during SE. Some early reports indicate that auxins and in vitro conditions modify the levels of DNA methylation in embryogenic cells. The changes in DNA methylation patterns are associated with the regulation of several genes involved in SE, such as WUS, BBM1, LEC, and several others. In this review, we highlight the more recent discoveries in the understanding of the role of epigenetic regulation of SE. In addition, we include a survey of different approaches to the study of SE, and new opportunities to focus SE studies. PMID:26347757

Sonic Hedgehog modulates EGFR dependent proliferation of neural stem cells during late mouse embryogenesis through EGFR transactivation

PubMed Central

Reinchisi, Gisela; Parada, Margarita; Lois, Pablo; Oyanadel, Claudia; Shaughnessy, Ronan; Gonzalez, Alfonso; Palma, Verónica

2013-01-01

Sonic Hedgehog (Shh/GLI) and EGFR signaling pathways modulate Neural Stem Cell (NSC) proliferation. How these signals cooperate is therefore critical for understanding normal brain development and function. Here we report a novel acute effect of Shh signaling on EGFR function. We show that during late neocortex development, Shh mediates the activation of the ERK1/2 signaling pathway in Radial Glial cells (RGC) through EGFR transactivation. This process is dependent on metalloprotease activity and accounts for almost 50% of the EGFR-dependent mitogenic response of late NSCs. Furthermore, in HeLa cancer cells, a well-known model for studying the EGFR receptor function, Shh also induces cell proliferation involving EGFR activation, as reflected by EGFR internalization and ERK1/2 phosphorylation. These findings may have important implications for understanding the mechanisms that regulate NSC proliferation during neurogenesis and may lead to novel approaches to the treatment of tumors. PMID:24133411

Somatic embryogenesis and plant regeneration of northern red oak (Quercus rubra L.)

Treesearch

G. Vengadesan; Paula M. Pijut

2009-01-01

A somatic embryogenesis protocol for plant regeneration of northern red oak (Quercus rubra) was established from immature cotyledon explants. Embryogenic callus cultures were induced on Murashige and Skoog medium (MS) containing 3% sucrose, 0.24% Phytagel™, and various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) after 4 weeks of...

Changes in ecdysteroid levels and expression patterns of ecdysteroid-responsive factors and neuropeptide hormones during the embryogenesis of the blue crab, Callinectes sapidus.

PubMed

Techa, Sirinart; Alvarez, Javier V; Sook Chung, J

2015-04-01

Embryogenesis requires the involvement and coordination of multiple networks of various genes, according to a timeline governing development. Crustacean embryogenesis usually includes the first molt, a process that is known to be positively controlled by ecdysteroids. We determined the amounts of ecdysteroids, as well as other related factors: the ecdysone receptor (CasEcR), the retinoid X receptor (CasRXR), the molt-inhibiting hormone (CasMIH), and crustacean hyperglycemic hormone (CasCHH) during the ovarian and embryonic developments of Callinectes sapidus. In summary, the ovaries at stages 1-4 have expression levels of maternal CasEcR and CasRXR 10-50 times higher than levels seen in embryos at the yolk stage. This large difference in the amount of the these factors in C. sapidus ovaries suggests that these maternal ecdysteroid-responsive factors may be utilized at the initiation of embryogenesis. During embryogenesis, the changes in total ecdysteroids and levels of CasEcR and CasRXR expression are similar to those observed in juvenile molts. The full-length cDNA sequence of the C. sapidus BTB domain protein (CasBTBDP) initially isolated from Y-organ cDNA, contains only Broad-Complex, Tramtrack, and Bric a brac (BTB) domains. The levels of CasBTBDP are kept constant throughout embryogenesis. The expression profiles of CasMIH and CasCHH are similar to the titers of ecdysteroids. However, the timing of their appearance is followed by increases in CasEcRs and CasRXRs, implying that the expressions of these neuropeptides may be influenced by ecdysteroids. Moreover, the ecdysteroid profile during embryogenesis may track directly with the timing of organogenesis of Y-organs and their activity. Our work reports, for first time, the observed expression and changes of ecdysteroid-responsive factors, along with CasCHH and CasMIH, during embryogenesis in the crustacean C. sapidus. Copyright © 2014 Elsevier Inc. All rights reserved.

Longitudinal Development of Phonology and Morphology in Children with Late-Identified Mild-Moderate Sensorineural Hearing Loss

PubMed Central

Moeller, Mary Pat; McCleary, Elizabeth; Putman, Coille; Tyler-Krings, Amy; Hoover, Brenda; Stelmachowicz, Patricia

2010-01-01

Objective Studies of language development in children with mild-moderate hearing loss are relatively rare. Longitudinal studies of children with late-identified hearing loss have not been conducted, and they are relevant for determining how a period of unaided mild-moderate hearing loss impacts development. In recent years, newborn hearing screening programs have effectively reduced the ages of identification for most children with permanent hearing loss. However, some children continue to be identified late and research is needed to guide management decisions. Further, studies of this group may help to discern if language normalizes following intervention, and/or if certain aspects of language might be vulnerable to persistent delays. The current study examines the impact of late identification and reduced audibility on speech and language outcomes via a longitudinal study of four children with mild-moderate sensorineural hearing loss. Design Longitudinal outcomes of four children with late-identified mild-moderate sensorinueral hearing loss were studied using standardized measures and language sampling procedures, from at or near the point of identification (28 – 41 months) through 84 months of age. The children with hearing loss were compared to ten age-matched children with normal hearing on a majority of the measures through 60 months of age. Spontaneous language samples were collected from mother-child interaction sessions, recorded at consistent intervals in a laboratory-based play setting. Transcripts were analyzed using computer-based procedures (Systematic Analysis of Language Transcripts) and the Index of Productive Syntax. Possible influences of audibility were explored by examining the onset and productive use of a set of verb tense markers, and by monitoring the children’s accuracy in use of morphological endings. Phonological samples at baseline were transcribed and analyzed using Computerized Profiling. Results At entry to the study, the four

5-azacytidine promotes microspore embryogenesis initiation by decreasing global DNA methylation, but prevents subsequent embryo development in rapeseed and barley

PubMed Central

Solís, María-Teresa; El-Tantawy, Ahmed-Abdalla; Cano, Vanesa; Risueño, María C.; Testillano, Pilar S.

2015-01-01

Microspores are reprogrammed by stress in vitro toward embryogenesis. This process is an important tool in breeding to obtain double-haploid plants. DNA methylation is a major epigenetic modification that changes in differentiation and proliferation. We have shown changes in global DNA methylation during microspore reprogramming. 5-Azacytidine (AzaC) cannot be methylated and leads to DNA hypomethylation. AzaC is a useful demethylating agent to study DNA dynamics, with a potential application in microspore embryogenesis. This work analyzes the effects of short and long AzaC treatments on microspore embryogenesis initiation and progression in two species, the dicot Brassica napus and the monocot Hordeum vulgare. This involved the quantitative analyses of proembryo and embryo production, the quantification of DNA methylation, 5-methyl-deoxy-cytidine (5mdC) immunofluorescence and confocal microscopy, and the analysis of chromatin organization (condensation/decondensation) by light and electron microscopy. Four days of AzaC treatments (2.5 μM) increased embryo induction, response associated with a decrease of DNA methylation, modified 5mdC, and heterochromatin patterns compared to untreated embryos. By contrast, longer AzaC treatments diminished embryo production. Similar effects were found in both species, indicating that DNA demethylation promotes microspore reprogramming, totipotency acquisition, and embryogenesis initiation, while embryo differentiation requires de novo DNA methylation and is prevented by AzaC. This suggests a role for DNA methylation in the repression of microspore reprogramming and possibly totipotency acquisition. Results provide new insights into the role of epigenetic modifications in microspore embryogenesis and suggest a potential benefit of inhibitors, such as AzaC, to improve the process efficiency in biotechnology and breeding programs. PMID:26161085

Arsenic Exposure to Killifish During Embryogenesis Alters Muscle Development

PubMed Central

Gaworecki, Kristen M.; Chapman, Robert W.; Neely, Marion G.; D’Amico, Angela R.; Bain, Lisa J.

2012-01-01

Epidemiological studies have correlated arsenic exposure in drinking water with adverse developmental outcomes such as stillbirths, spontaneous abortions, neonatal mortality, low birth weight, delays in the use of musculature, and altered locomotor activity. Killifish (Fundulus heteroclitus) were used as a model to help to determine the mechanisms by which arsenic could impact development. Killifish embryos were exposed to three different sodium arsenite concentrations and were collected at 32 h post-fertilization (hpf), 42 hpf, 168 hpf, or < 24 h post-hatch. A killifish oligo microarray was developed and used to examine gene expression changes between control and 25-ppm arsenic-exposed hatchlings. With artificial neural network analysis of the transcriptomic data, accurate prediction of each group (control vs. arsenic-exposed embryos) was obtained using a small subset of only 332 genes. The genes differentially expressed include those involved in cell cycle, development, ubiquitination, and the musculature. Several of the genes involved in cell cycle regulation and muscle formation, such as fetuin B, cyclin D–binding protein 1, and CapZ, were differentially expressed in the embryos in a time- and dose-dependent manner. Examining muscle structure in the hatchlings showed that arsenic exposure during embryogenesis significantly reduces the average muscle fiber size, which is coupled with a significant 2.1- and 1.6-fold upregulation of skeletal myosin light and heavy chains, respectively. These findings collectively indicate that arsenic exposure during embryogenesis can initiate molecular changes that appear to lead to aberrant muscle formation. PMID:22058191

Nuclear lamins and peripheral nuclear antigens during fertilization and embryogenesis in mice and sea urchins

NASA Technical Reports Server (NTRS)

Schatten, G.; Schatten, H.; Simerly, C.; Maul, G. G.; Chaly, N.

1985-01-01

Nuclear structural changes during fertilization and embryogenesis in mice and sea urchins are traced using four antibodies. The oocytes from virgin female mice, morulae and blastocytes from mated females, and gametes from the sea urchin Lytechnius variegatis are studied using mouse monoclonal antibodies to nuclear lamin A/C, monoclonal antibody to P1, human autoimmune antibodies to lamin A/C, and to lamin B. The mouse fertilization data reveal no lamins on the oocyte; however, lamins are present on the pronuclei, and chromosomes are found on the oocytes and pronuclei. It is detected that on the sea urchin sperm the lamins are reduced to acrosomal and centriolar fossae and peripheral antigens are around the sperm nucleus. The mouse sperm bind lamin antibodies regionally and do not contain antigens. Lamins and antigens are observed on both pronuclei and chromosomes during sea urchin fertilization. Mouse embryogenesis reveals that lamin A/C is not recognized at morula and blastocyst stages; however, lamin B stains are retained. In sea urchin embryogenesis lamin recognition is lost at the blastrula, gastrula, and plutei stages. It is noted that nuclear lamins lost during spermatogenesis are restored at fertilization and peripheral antigens are associated with the surface of chromosomes during meiosis and mitosis and with the periphery of the pronuclei and nuclei during interphase.

A microdroplet cell culture based high frequency somatic embryogenesis system for pigeonpea, Cajanus cajan (L.) Millsp.

PubMed

Kumar, Nagan Udhaya; Gnanaraj, Muniraj; Sindhujaa, Vajravel; Viji, Maluventhen; Manoharan, Kumariah

2015-09-01

A protocol for high frequency production of somatic embryos was worked out in pigeonpea, Cajanus cajan (L.) Millsp. The protocol involved sequential employment of embryogenic callus cultures, low density cell suspension cultures and a novel microdroplet cell culture system. The microdroplet cell cultures involved culture of a single cell in 10 μI of Murashige and Skoog's medium supplemented with phytohormones, growth factors and phospholipid precursors. By employing the microdroplet cell cultures, single cells in isolation were grown into cell clones which developed somatic embryos. Further, 2,4-dichlorophenoxyacetic acid, kinetin, polyethylene glycol, putrescine, spermine, spermidine, choline chloride, ethanolamine and LiCl were supplemented to the low density cell suspension cultures and microdroplet cell cultures to screen for their cell division and somatic embryogenesis activity. Incubation of callus or the inoculum employed for low density cell suspension cultures and microdroplet cell cultures with polyethylene glycol was found critical for induction of somatic embryogenesis. Somatic embryogenesis at a frequency of 1.19, 3.16 and 6.51 per 10(6) cells was achieved in the callus, low density cell suspension cultures and microdroplet cell cultures, respectively. Advantages of employing microdroplet cell cultures for high frequency production of somatic embryos and its application in genetic transformation protocols are discussed.

Efficacy of Zingiber officinale ethanol extract on the viability, embryogenesis and infectivity of Toxocara canis eggs.

PubMed

El-Sayed, Nagwa Mostafa

2017-12-01

This study evaluated the effect of Zingiber officinal e ( Z. officinal e) ethanol extract on the viability, embryogenesis and infectivity Toxocara canis ( T. canis ) eggs. It was carried out both in vitro and in vivo. In the in vitro experiment, unembryonated T. canis eggs were incubated with 25, 50 and 100 mg/mL Z. officinal e extract at 25 °C for 6, 12, and 24 h to assess the effect of Z. officinal e on their viability and for two weeks to assess the effect of Z. officinal e on their embryogenesis. In vivo experiment was performed to assess the effect of Z. officinal e on infectivity of T. canis eggs. Treated embryonated eggs by Z. officinale extract at concentrations of 25, 50 and 100 mg/mL for 24 h were inoculated into mice and their livers were examined for the presence of T. canis larvae on the 7th day after infection and for histopathological evaluation at 14th day post-infection. Z. officinal e showed a significant ovicidal activity on T. canis eggs. The best effect was observed with 100 mg/mL concentration after 24 h with an efficacy of 98.2%. However, the treated eggs by 25, 50 mg/mL of Z. officinale extract after 24 h showed ovicidal activity by 59.22 and 82.5% respectively. Moreover, this extract effectively inhibited T. canis eggs embryogenesis by 99.64% and caused their degeneration at the concentration of 100 mg/mL after 2 weeks of treatment. However, the lower concentrations, 25 and 50 mg/mL inhibited embryogenesis by 51.19 and 78.57% respectively. The effect of Z. officinal e on the infectivity T. canis eggs was proven by the reduction of larvae recovery in the livers by 35.9, 62.8 and 89.5% in mice groups inoculated by Z. officinale treated eggs at concentrations of 25, 50 and 100 mg/mL respectively. Histopathologically, the liver tissues of mice infected with Z. officinale treated eggs at the concentration of 100 mg/mL appeared healthy with slight degenerative changes of hepatocytes, opposite to that recorded in the infected mice

Impaired imprinting and social behaviors in chicks exposed to mifepristone, a glucocorticoid receptor antagonist, during the final week of embryogenesis.

PubMed

Nishigori, Hideo; Kagami, Keisuke; Nishigori, Hidekazu

2014-03-15

The effects of glucocorticoid receptor dysfunction during embryogenesis on the imprinting abilities and social behaviors of hatchlings were examined using "fertile hen's egg-embryo-chick" system. Of embryos treated with mifepristone (0.4μmol/egg) on day 14, over 75% hatched a day later than the controls (day 22) without external anomalies. The mifepristone-treated hatchlings were assayed for imprinting ability on post-hatching day 2 and for social behaviors on day 3. The findings were as follows: imprinting ability (expressed as preference score) was significantly lower in mifepristone-treated hatchlings than in controls (0.65±0.06 vs. 0.92±0.02, P<0.005). Aggregation tests to evaluate the speed (seconds) required for four chicks, individually isolated with cardboard dividers in a box, to form a group after removal of the barriers showed that aggregation was significantly slower in mifepristone-treated hatchlings than in controls (8.7±1.1 vs. 2.6±0.3, P<0.001). In belongingness tests to evaluate the speed (seconds) for a chick isolated at a corner to join a group of three chicks placed at the opposite corner, mifepristone-treated hatchlings took significantly longer than controls (4.5±0.4/40 cm vs. 2.4±0.08/40 cm, P<0.001). In vocalization tests, using a decibel meter to measure average decibel level/30s (chick vocalization), mifepristone-treated hatchlings had significantly weaker vocalizations than controls (14.2±1.9/30s vs. 26.4±1.3/30s P<0.001). In conclusion, glucocorticoid receptor dysfunction during the last week embryogenesis altered the programming of brain development, resulting in impaired behavioral activities in late life. Copyright © 2013 Elsevier B.V. All rights reserved.

Somatic embryogenesis and plant regeneration in Carica papaya L. tissue culture derived from root explants.

PubMed

Chen, M H; Wang, P J; Maeda, E

1987-10-01

The regeneration potential of shoot tip, stem, leaf, cotyledon and root explants of two papaya cultivars (Carica papaya cv. 'Solo' and cv. 'Sunrise') were studed. Callus induction of these two cultivars of papaya showed that the shoot tips and stems are most suitable for forming callus, while leaves, cotyledons and roots are comparatively difficult to induce callus. Callus induction also varied with the varities. Somatic embryogenesis was obtained from 3-month-old root cultures. A medium containing half strength of MS inorganic salts, 160 mg/l adenine sulfate, 1.0 mg/1 NAA, 0.5 mg/1 kinetin and 1.0 mg/1 GA3 was optimal for embryogenesis. The callus maintained high regenerative capacity after two years of culture on this medium. Plants derived from somatic embryos were obtained under green-house conditions.

Expression profiling identifies novel Hh/Gli regulated genes in developing zebrafish embryos.

PubMed Central

Bergeron, Sadie A.; Milla, Luis A.; Villegas, Rosario; Shen, Meng-Chieh; Burgess, Shawn M.; Allende, Miguel L.; Karlstrom, Rolf O.; Palma, Verónica

2008-01-01

The Hedgehog (Hh) signaling pathway plays critical instructional roles during embryonic development. Mis-regulation of Hh/Gli signaling is a major causative factor in human congenital disorders and in a variety of cancers. The zebrafish is a powerful genetic model for the study of Hh signaling during embryogenesis, as a large number of mutants have been identified affecting different components of the Hh/Gli signaling system. By performing global profiling of gene expression in different Hh/Gli gain- and loss-of-function scenarios we identified several known (e.g. ptc1 and nkx2.2a) as well as a large number of novel Hh regulated genes that are differentially expressed in embryos with altered Hh/Gli signaling function. By uncovering changes in tissue specific gene expression, we revealed new embryological processes that are influenced by Hh signaling. We thus provide a comprehensive survey of Hh/Gli regulated genes during embryogenesis and we identify new Hh-regulated genes that may be targets of mis-regulation during tumorogenesis. PMID:18055165

Annual Reproductive Cycle and Unusual Embryogenesis of a Temperate Coral in the Mediterranean Sea

PubMed Central

Marchini, Chiara; Airi, Valentina; Fontana, Roberto; Tortorelli, Giada; Rocchi, Marta; Falini, Giuseppe; Levy, Oren; Dubinsky, Zvy; Goffredo, Stefano

2015-01-01

The variety of reproductive processes and modes among coral species reflects their extraordinary regeneration ability. Scleractinians are an established example of clonal animals that can exhibit a mixed strategy of sexual and asexual reproduction to maintain their populations. This study provides the first description of the annual reproductive cycle and embryogenesis of the temperate species Caryophyllia inornata. Cytometric analyses were used to define the annual development of germ cells and embryogenesis. The species was gonochoric with three times more male polyps than female. Polyps were sexually mature from 6 to 8 mm length. Not only females, but also sexually inactive individuals (without germ cells) and males were found to brood their embryos. Spermaries required 12 months to reach maturity, while oogenesis seemed to occur more rapidly (5–6 months). Female polyps were found only during spring and summer. Furthermore, the rate of gamete development in both females and males increased significantly from March to May and fertilization was estimated to occur from April to July, when mature germ cells disappeared. Gametogenesis showed a strong seasonal influence, while embryos were found throughout the year in males and in sexually inactive individuals without a defined trend. This unusual embryogenesis suggests the possibility of agamic reproduction, which combined with sexual reproduction results in high fertility. This mechanism is uncommon and only four other scleractinians (Pocillopora damicornis, Tubastraea diaphana, T. coccinea and Oulastrea crispata) have been shown to generate their broods asexually. The precise nature of this process is still unknown. PMID:26513159

Small RNA profiling and degradome analysis reveal regulation of microRNA in peanut embryogenesis and early pod development.

PubMed

Gao, Chao; Wang, Pengfei; Zhao, Shuzhen; Zhao, Chuanzhi; Xia, Han; Hou, Lei; Ju, Zheng; Zhang, Ye; Li, Changsheng; Wang, Xingjun

2017-03-02

As a typical geocarpic plant, peanut embryogenesis and pod development are complex processes involving many gene regulatory pathways and controlled by appropriate hormone level. MicroRNAs (miRNAs) are small non-coding RNAs that play indispensable roles in post-transcriptional gene regulation. Recently, identification and characterization of peanut miRNAs has been described. However, whether miRNAs participate in the regulation of peanut embryogenesis and pod development has yet to be explored. In this study, small RNA and degradome libraries from peanut early pod of different developmental stages were constructed and sequenced. A total of 70 known and 24 novel miRNA families were discovered. Among them, 16 miRNA families were legume-specific and 12 families were peanut-specific. 30 known and 10 novel miRNA families were differentially expressed during pod development. In addition, 115 target genes were identified for 47 miRNA families by degradome sequencing. Several new targets that might be specific to peanut were found and further validated by RNA ligase-mediated rapid amplification of 5' cDNA ends (RLM 5'-RACE). Furthermore, we performed profiling analysis of intact and total transcripts of several target genes, demonstrating that SPL (miR156/157), NAC (miR164), PPRP (miR167 and miR1088), AP2 (miR172) and GRF (miR396) are actively modulated during early pod development, respectively. Large numbers of miRNAs and their related target genes were identified through deep sequencing. These findings provided new information on miRNA-mediated regulatory pathways in peanut pod, which will contribute to the comprehensive understanding of the molecular mechanisms that governing peanut embryo and early pod development.

Genome editing reveals a role for OCT4 in human embryogenesis.

PubMed

Fogarty, Norah M E; McCarthy, Afshan; Snijders, Kirsten E; Powell, Benjamin E; Kubikova, Nada; Blakeley, Paul; Lea, Rebecca; Elder, Kay; Wamaitha, Sissy E; Kim, Daesik; Maciulyte, Valdone; Kleinjung, Jens; Kim, Jin-Soo; Wells, Dagan; Vallier, Ludovic; Bertero, Alessandro; Turner, James M A; Niakan, Kathy K

2017-10-05

Despite their fundamental biological and clinical importance, the molecular mechanisms that regulate the first cell fate decisions in the human embryo are not well understood. Here we use CRISPR-Cas9-mediated genome editing to investigate the function of the pluripotency transcription factor OCT4 during human embryogenesis. We identified an efficient OCT4-targeting guide RNA using an inducible human embryonic stem cell-based system and microinjection of mouse zygotes. Using these refined methods, we efficiently and specifically targeted the gene encoding OCT4 (POU5F1) in diploid human zygotes and found that blastocyst development was compromised. Transcriptomics analysis revealed that, in POU5F1-null cells, gene expression was downregulated not only for extra-embryonic trophectoderm genes, such as CDX2, but also for regulators of the pluripotent epiblast, including NANOG. By contrast, Pou5f1-null mouse embryos maintained the expression of orthologous genes, and blastocyst development was established, but maintenance was compromised. We conclude that CRISPR-Cas9-mediated genome editing is a powerful method for investigating gene function in the context of human development.

Effect of ovary induction on bread wheat anther culture: ovary genotype and developmental stage, and candidate gene association

PubMed Central

Castillo, Ana M.; Sánchez-Díaz, Rosa A.; Vallés, María P.

2015-01-01

Ovary pre-conditioned medium and ovary co-culture increased the efficiency of green doubled haploid plant production in bread wheat anther culture. The positive effect of this medium led to a 6- and 11-fold increase in the numbers of embryos and green plants, respectively, having a greater effect on a medium-low responding cultivar. Ovary genotype and developmental stage significantly affected microspore embryogenesis. By the use of Caramba ovaries it was possible to reach a 2-fold increase in the number of embryos and green plants, and to decrease the rate of albinism. Mature ovaries from flowers containing microspores at a late binucleate stage raised the number of embryos and green plants by 25–46% as compared to immature ovaries (excised from flowers with microspores at a mid-late uninucleate stage). The highest numbers of embryos and green plants were produced when using mature Caramba ovaries. Ovaries from Galeón, Tigre, and Kilopondio cultivars successfully induced microspore embryogenesis at the same rate as Caramba ovaries. Moreover, Tigre ovaries raised the percentage of spontaneous chromosome doubling up to 71%. Attempts were made to identify molecular mechanisms associated to the inductive effect of the ovaries on microspore embryogenesis. The genes TAA1b, FLA26, and WALI6 associated to wheat microspore embryogenesis, the CGL1 gene involved in glycan biosynthesis or degradation, and the FER gene involved in the ovary signaling process were expressed and/or induced at different rates during ovary culture. The expression pattern of FLA26 and FER could be related to the differences between genotypes and developmental stages in the inductive effect of the ovary. Our results open opportunities for new approaches to increase bread wheat doubled haploid production by anther culture, and to identify the functional components of the ovary inductive effect on microspore embryogenesis. PMID:26150821

Traces of embryogenesis are the same in monozygotic and dizygotic twins: not compatible with double ovulation.

PubMed

Boklage, Charles E

2009-06-01

Common knowledge of over a century has it that monozygotic and dizygotic twinning events occur by unrelated mechanisms: monozygotic twinning 'splits' embryos, producing anomalously re-arranged embryogenic asymmetries; dizygotic twinning begins with independent ovulations yielding undisturbed parallel embryogeneses with no expectation of departures from singleton outcomes. The anomalies statistically associated with twin births are due to the re-arranged embryos of the monozygotics. Common knowledge further requires that dizygotic pairs are dichorionic; monochorionicity is exclusive to monozygotic pairs. These are fundamental certainties in the literature of twin biology. Multiple observations contradict those common knowledge understandings. The double ovulation hypothesis of dizygotic twinning is untenable. Girl-boy twins differ subtly from all other humans of either sex, absolutely not representative of all dizygotics. Embryogenesis of dizygotic twins differs from singleton development at least as much as monozygotic embryogenesis does, and in the same ways, and the differences between singletons and twins of both zygosities represent a coherent system of re-arranged embryogenic asymmetries. Dizygotic twinning and monozygotic twinning have the same list of consequences of anomalous embryogenesis. Those include an unignorable fraction of dizygotic pairs that are in fact monochorionic, plus many more sharing co-twins' cells in tissues other than a common chorion. The idea that monozygotic and dizygotic twinning events arise from the same embryogenic mechanism is the only plausible hypothesis that might explain all of the observations.

[Direct and indirect somatic embryogenesis in Freesia refracta].

PubMed

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

1999-06-01

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

Annotation of differentially expressed genes in the somatic embryogenesis of musa and their location in the banana genome.

PubMed

Maldonado-Borges, Josefina Ines; Ku-Cauich, José Roberto; Escobedo-Graciamedrano, Rosa Maria

2013-01-01

Analysis of cDNA-AFLP was used to study the genes expressed in zygotic and somatic embryogenesis of Musa acuminata Colla ssp. malaccensis, and a comparison was made between their differential transcribed fragments (TDFs) and the sequenced genome of the double haploid- (DH-) Pahang of the malaccensis subspecies that is available in the network. A total of 253 transcript-derived fragments (TDFs) were detected with apparent size of 100-4000 bp using 5 pairs of AFLP primers, of which 21 were differentially expressed during the different stages of banana embryogenesis; 15 of the sequences have matched DH-Pahang chromosomes, with 7 of them being homologous to gene sequences encoding either known or putative protein domains of higher plants. Four TDF sequences were located in all Musa chromosomes, while the rest were located in one or two chromosomes. Their putative individual function is briefly reviewed based on published information, and the potential roles of these genes in embryo development are discussed. Thus the availability of the genome of Musa and the information of TDFs sequences presented here opens new possibilities for an in-depth study of the molecular and biochemical research of zygotic and somatic embryogenesis of Musa.

Homologue of Sox10 in Misgurnus anguillicaudatus: sequence, expression pattern during early embryogenesis.

PubMed

Xia, Xiaohua; Nan, Ping; Zhang, Linxia; Sun, Jinsheng; Chang, Zhongjie

2013-10-01

A number of genetic studies have established that Sox10 is a transcription factor associated with neurogenesis in vertebrates. We have isolated a homologue of Sox10 gene from the brain of Misgurnus anguillicaudatus by using homologous cloning and RACE method, designated as MaSox10b. The full-length cDNA of MaSox10b contained a 311 bp 5'UTR, a 312 bp 3'UTR and an ORF encoding a putative protein of 490 amino acids with a characteristic HMG-box DNA-binding domain of 79 amino acids (aa: 105-183). Phylogenetic tree shows that the MaSOX10b fits within the Sox10 clade and clusters firmly into Sox10b branches. During embryogenesis, MaSox10b was first detected in gastrulae stage. From somitogenesis stage and thereafter, distinct expression was observed in the medial neural tube, extending from the hindbrain through the posterior trunk. Taken together, these preliminary findings suggested that MaSox10b is highly conserved during vertebrate evolution and involved in a wide range of developmental processes including embryogenesis and neurogenesis.

Embryogenesis induction, callogenesis, and plant regeneration by in vitro culture of tomato isolated microspores and whole anthers.

PubMed

Seguí-Simarro, José M; Nuez, Fernando

2007-01-01

In this work, some of the different in vitro developmental pathways into which tomato microspores or microsporocytes can be deviated experimentally were explored. The two principal ones are direct embryogenesis from isolated microspores and callus formation from meiocyte-containing anthers. By means of light and electron microscopy, the process of early embryogenesis from isolated microspores and the disruption of normal meiotic development and change of developmental fate towards callus proliferation, morphogenesis, and plant regeneration have been shown. From microspores isolated at the vacuolate stage, embryos can be directly induced, thus avoiding non-androgenic products. In contrast, several different morphogenic events can be triggered in cultures of microsporocyte-containing anthers under adequate conditions, including indirect embryogenesis, adventitious organogenesis, and plant regeneration. Both callus and regenerated plants may be haploid, diploid, and mostly mixoploid. The results demonstrate that both gametophytic and sporophytic calli occur in cultured tomato anthers, and point to an in vitro-induced disturbance of cytokinesis and subsequent fusion of daughter nuclei as a putative cause for mixoploidy and genome doubling during both tetrad compartmentalization and callus proliferation. The potential implications of the different alternative pathways are discussed in the context of their application to the production of doubled-haploid plants in tomato, which is still very poorly developed.

Inducible somatic embryogenesis in Theobroma cacao achieved using the DEX-activatable transcription factor-glucocorticoid receptor fusion.

PubMed

Shires, Morgan E; Florez, Sergio L; Lai, Tina S; Curtis, Wayne R

2017-11-01

To carry out mass propagation of superior plants to improve agricultural and silvicultural production though advancements in plant cell totipotency, or the ability of differentiated somatic plant cells to regenerate an entire plant. The first demonstration of a titratable control over somatic embryo formation in a commercially relevant plant, Theobroma cacao (Chocolate tree), was achieved using a dexamethasone activatable chimeric transcription factor. This four-fold enhancement in embryo production rate utilized a glucocorticoid receptor fused to an embryogenic transcription factor LEAFY COTYLEDON 2. Where previous T. cacao somatic embryogenesis has been restricted to dissected flower parts, this construct confers an unprecedented embryogenic potential to leaves. Activatable chimeric transcription factors provide a means for elucidating the regulatory cascade associated with plant somatic embryogenesis towards improving its use for somatic regeneration of transgenics and plant propagation.

Calcium-mediated signaling during sandalwood somatic embryogenesis. Role for exogenous calcium as second messenger.

PubMed

Anil, V S; Rao, K S

2000-08-01

The possible involvement of Ca(2+)-mediated signaling in the induction/regulation of somatic embryogenesis from pro-embryogenic cells of sandalwood (Santalum album) has been investigated. (45)Ca(2+)-uptake studies and fura-2 fluorescence ratio photometry were used to measure changes in [Ca(2+)](cyt) of pro-embryogenic cells in response to culture conditions conducive for embryo development. Sandalwood pro-embryogenic cell masses (PEMs) are obtained in the callus proliferation medium that contains the auxin 2,4-dichlorophenoxyacetic acid. Subculture of PEMs into the embryo differentiation medium, which lacks 2,4-dichlorophenoxyacetic acid and has higher osmoticum, results in a 4-fold higher (45)Ca(2+) incorporation into the symplast. Fura-2 ratiometric analysis corroboratively shows a 10- to 16-fold increase in the [Ca(2+)](cyt) of PEMs, increasing from a resting concentration of 30 to 50 nM to 650 to 800 nM. Chelation of exogenous Ca(2+) with ethyleneglycol-bis(aminoethyl ether)-N,N'-tetraacetic acid arrests such an elevation in [Ca(2+)](cyt). Exogenous Ca(2+) when chelated or deprived also arrests embryo development and inhibits the accumulation of a sandalwood Ca(2+)-dependent protein kinase. However, such culture conditions do not cause cell death as the PEMs continue to proliferate to form larger cell clumps. Culture treatment with N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide reduced embryogenic frequency by 85%, indicating that blockage of Ca(2+)-mediated signaling pathway(s) involving sandalwood Ca(2+)-dependent protein kinase and/or calmodulin causes the inhibition of embryogenesis. The observations presented are evidence to suggest a second messenger role for exogenous Ca(2+) during sandalwood somatic embryogenesis.

3D early embryogenesis image filtering by nonlinear partial differential equations.

PubMed

Krivá, Z; Mikula, K; Peyriéras, N; Rizzi, B; Sarti, A; Stasová, O

2010-08-01

We present nonlinear diffusion equations, numerical schemes to solve them and their application for filtering 3D images obtained from laser scanning microscopy (LSM) of living zebrafish embryos, with a goal to identify the optimal filtering method and its parameters. In the large scale applications dealing with analysis of 3D+time embryogenesis images, an important objective is a correct detection of the number and position of cell nuclei yielding the spatio-temporal cell lineage tree of embryogenesis. The filtering is the first and necessary step of the image analysis chain and must lead to correct results, removing the noise, sharpening the nuclei edges and correcting the acquisition errors related to spuriously connected subregions. In this paper we study such properties for the regularized Perona-Malik model and for the generalized mean curvature flow equations in the level-set formulation. A comparison with other nonlinear diffusion filters, like tensor anisotropic diffusion and Beltrami flow, is also included. All numerical schemes are based on the same discretization principles, i.e. finite volume method in space and semi-implicit scheme in time, for solving nonlinear partial differential equations. These numerical schemes are unconditionally stable, fast and naturally parallelizable. The filtering results are evaluated and compared first using the Mean Hausdorff distance between a gold standard and different isosurfaces of original and filtered data. Then, the number of isosurface connected components in a region of interest (ROI) detected in original and after the filtering is compared with the corresponding correct number of nuclei in the gold standard. Such analysis proves the robustness and reliability of the edge preserving nonlinear diffusion filtering for this type of data and lead to finding the optimal filtering parameters for the studied models and numerical schemes. Further comparisons consist in ability of splitting the very close objects which

PRC2 Represses Hormone-Induced Somatic Embryogenesis in Vegetative Tissue of Arabidopsis thaliana

PubMed Central

Mozgová, Iva

2017-01-01

Many plant cells can be reprogrammed into a pluripotent state that allows ectopic organ development. Inducing totipotent states to stimulate somatic embryo (SE) development is, however, challenging due to insufficient understanding of molecular barriers that prevent somatic cell dedifferentiation. Here we show that Polycomb repressive complex 2 (PRC2)-activity imposes a barrier to hormone-mediated transcriptional reprogramming towards somatic embryogenesis in vegetative tissue of Arabidopsis thaliana. We identify factors that enable SE development in PRC2-depleted shoot and root tissue and demonstrate that the establishment of embryogenic potential is marked by ectopic co-activation of crucial developmental regulators that specify shoot, root and embryo identity. Using inducible activation of PRC2 in PRC2-depleted cells, we demonstrate that transient reduction of PRC2 activity is sufficient for SE formation. We suggest that modulation of PRC2 activity in plant vegetative tissue combined with targeted activation of developmental pathways will open possibilities for novel approaches to cell reprogramming. PMID:28095419

Expression profiling of the solute carrier gene family in chicken intestine from the late embryonic to early post-hatch stages.

PubMed

Li, H; Gilbert, E R; Zhang, Y; Crasta, O; Emmerson, D; Webb, K E; Wong, E A

2008-08-01

Intestinal development during late embryogenesis and early post-hatch has a long-term influence on digestive and absorptive capacity in chickens. The objective of this research was to obtain a global view of intestinal solute carrier (SLC) gene family member expression from late embryogenesis until 2 weeks post-hatch with a focus on SLC genes involved in uptake of sugars and amino acids. Small intestine samples from male chicks were collected on embryonic days 18 (E18) and 20 (E20), day of hatch and days 1, 3, 7 and 14 post-hatch. The expression profiles of 162 SLC genes belonging to 41 SLC families were determined using Affymetrix chicken genome microarrays. The majority of SLC genes showed little or no difference in level of expression during E18-D14. A number of well-known intestinal transporters were upregulated between E18 and D14 including the amino acid transporters rBAT, y(+)LAT-2 and EAAT3, the peptide transporter PepT1 and the sugar transporters SGLT1, GLUT2 and GLUT5. The amino acid transporters CAT-1 and CAT-2 were downregulated. In addition, several glucose and amino acid transporters that are novel to our understanding of nutrient absorption in the chicken intestine were discovered through the arrays (SGLT6, SNAT1, SNAT2 and AST). These results represent a comprehensive characterization of the expression profiles of the SLC family of genes at different stages of development in the chicken intestine and lay the ground work for future nutritional studies.

vasa and piwi are required for mitotic integrity in early embryogenesis in the spider Parasteatoda tepidariorum.

PubMed

Schwager, Evelyn E; Meng, Yue; Extavour, Cassandra G

2015-06-15

Studies in vertebrate and invertebrate model organisms on the molecular basis of primordial germ cell (PGC) specification have revealed that metazoans can specify their germ line either early in development by maternally transmitted cytoplasmic factors (inheritance), or later in development by signaling factors from neighboring tissues (induction). Regardless of the mode of PGC specification, once animal germ cells are specified, they invariably express a number of highly conserved genes. These include vasa and piwi, which can play essential roles in any or all of PGC specification, development, or gametogenesis. Although the arthropods are the most speciose animal phylum, to date there have been no functional studies of conserved germ line genes in species of the most basally branching arthropod clade, the chelicerates (which includes spiders, scorpions, and horseshoe crabs). Here we present the first such study by using molecular and functional tools to examine germ line development and the roles of vasa and piwi orthologues in the common house spider Parasteatoda (formerly Achaearanea) tepidariorum. We use transcript and protein expression patterns of Pt-vasa and Pt-piwi to show that primordial germ cells (PGCs) in the spider arise during late embryogenesis. Neither Pt-vasa nor Pt-piwi gene products are localized asymmetrically to any embryonic region before PGCs emerge as paired segmental clusters in opisthosomal segments 2-6 at late germ band stages. RNA interference studies reveal that both genes are required maternally for egg laying, mitotic progression in early embryos, and embryonic survival. Our results add to the growing body of evidence that vasa and piwi can play important roles in somatic development, and provide evidence for a previously hypothesized conserved role for vasa in cell cycle progression. Copyright © 2014 Elsevier Inc. All rights reserved.

Aberrant ligand-induced activation of G protein-coupled estrogen receptor 1 (GPER) results in developmental malformations during vertebrate embryogenesis.

PubMed

Jayasinghe, B Sumith; Volz, David C

2012-01-01

G protein-coupled estrogen receptor 1 (GPER) is a G protein-coupled receptor (GPCR) unrelated to nuclear estrogen receptors but strongly activated by 17β-estradiol in both mammals and fish. To date, the distribution and functional characterization of GPER within reproductive and nonreproductive vertebrate organs have been restricted to juvenile and adult animals. In contrast, virtually nothing is known about the spatiotemporal distribution and function of GPER during vertebrate embryogenesis. Using zebrafish as an animal model, we investigated the potential functional role and expression of GPER during embryogenesis. Based on real-time PCR and whole-mount in situ hybridization, gper was expressed as early as 1 h postfertilization (hpf) and exhibited strong stage-dependent expression patterns during embryogenesis. At 26 and 38 hpf, gper mRNA was broadly distributed throughout the body, whereas from 50 to 98 hpf, gper expression was increasingly localized to the heart, brain, neuromasts, craniofacial region, and somite boundaries of developing zebrafish. Continuous exposure to a selective GPER agonist (G-1)-but not continuous exposure to a selective GPER antagonist (G-15)-from 5 to 96 hpf, or within three developmental windows ranging from 10 to 72 hpf, resulted in adverse concentration-dependent effects on survival, gross morphology, and somite formation within the trunk of developing zebrafish embryos. Importantly, based on co-exposure studies, G-15 blocked severe G-1-induced developmental toxicity, suggesting that G-1 toxicity is mediated via aberrant activation of GPER. Overall, our findings suggest that xenobiotic-induced GPER activation represents a potentially novel and understudied mechanism of toxicity for environmentally relevant chemicals that affect vertebrate embryogenesis.

The Roles of the Wnt-Antagonists Axin and Lrp4 during Embryogenesis of the Red Flour Beetle Tribolium castaneum

PubMed Central

Prühs, Romy

2017-01-01

In both vertebrates and invertebrates, the Wnt-signaling pathway is essential for numerous processes in embryogenesis and during adult life. Wnt activity is fine-tuned at various levels by the interplay of a number of Wnt-agonists (Wnt ligands, Frizzled-receptors, Lrp5/6 coreceptors) and Wnt-antagonists (among them Axin, Secreted frizzled and Lrp4) to define anterior–posterior polarity of the early embryo and specify cell fate in organogenesis. So far, the functional analysis of Wnt-pathway components in insects has concentrated on the roles of Wnt-agonists and on the Wnt-antagonist Axin. We depict here additional features of the Wnt-antagonist Axin in the flour beetle Tribolium castaneum. We show that Tc-axin is dynamically expressed throughout embryogenesis and confirm its essential role in head development. In addition, we describe an as yet undetected, more extreme Tc-axin RNAi-phenotype, the ectopic formation of posterior abdominal segments in reverse polarity and a second hindgut at the anterior. For the first time, we describe here that an lrp4 ortholog is involved in axis formation in an insect. The Tribolium Lrp4 ortholog is ubiquitously expressed throughout embryogenesis. Its downregulation via maternal RNAi results in the reduction of head structures but not in axis polarity reversal. Furthermore, segmentation is impaired and larvae develop with a severe gap-phenotype. We conclude that, as in vertebrates, Tc-lrp4 functions as a Wnt-inhibitor in Tribolium during various stages of embryogenesis. We discuss the role of both components as negative modulators of Wnt signaling in respect to axis formation and segmentation in Tribolium. PMID:29615567

Validation of transcutaneous bilirubin nomogram for identifying neonatal hyperbilirubinemia in healthy Chinese term and late-preterm infants: a multicenter study.

PubMed

Yu, Zhangbin; Han, Shuping; Wu, Jinxia; Li, Mingxia; Wang, Huaiyan; Wang, Jimei; Liu, Jiebo; Pan, Xinnian; Yang, Jie; Chen, Chao

2014-01-01

to prospectively validate a previously constructed transcutaneous bilirubin (TcB) nomogram for identifying severe hyperbilirubinemia in healthy Chinese term and late-preterm infants. this was a multicenter study that included 9,174 healthy term and late-preterm infants in eight hospitals of China. TcB measurements were performed using a JM-103 bilirubinometer. TcB values were plotted on a previously developed TcB nomogram, to identify the predictive ability for subsequent significant hyperbilirubinemia. in the present study, 972 neonates (10.6%) developed significant hyperbilirubinemia. The 40(th) percentile of the nomogram could identify all neonates who were at risk of significant hyperbilirubinemia, but with a low positive predictive value (PPV) (18.9%). Of the 453 neonates above the 95(th) percentile, 275 subsequently developed significant hyperbilirubinemia, with a high PPV (60.7%), but with low sensitivity (28.3%). The 75(th) percentile was highly specific (81.9%) and moderately sensitive (79.8%). The area under the curve (AUC) for the TcB nomogram was 0.875. this study validated the previously developed TcB nomogram, which could be used to predict subsequent significant hyperbilirubinemia in healthy Chinese term and late-preterm infants. However, combining TcB nomogram and clinical risk factors could improve the predictive accuracy for severe hyperbilirubinemia, which was not assessed in the study. Further studies are necessary to confirm this combination. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Annotation of Differentially Expressed Genes in the Somatic Embryogenesis of Musa and Their Location in the Banana Genome

PubMed Central

Maldonado-Borges, Josefina Ines; Ku-Cauich, José Roberto; Escobedo-GraciaMedrano, Rosa Maria

2013-01-01

Analysis of cDNA-AFLP was used to study the genes expressed in zygotic and somatic embryogenesis of Musa acuminata Colla ssp. malaccensis, and a comparison was made between their differential transcribed fragments (TDFs) and the sequenced genome of the double haploid- (DH-) Pahang of the malaccensis subspecies that is available in the network. A total of 253 transcript-derived fragments (TDFs) were detected with apparent size of 100–4000 bp using 5 pairs of AFLP primers, of which 21 were differentially expressed during the different stages of banana embryogenesis; 15 of the sequences have matched DH-Pahang chromosomes, with 7 of them being homologous to gene sequences encoding either known or putative protein domains of higher plants. Four TDF sequences were located in all Musa chromosomes, while the rest were located in one or two chromosomes. Their putative individual function is briefly reviewed based on published information, and the potential roles of these genes in embryo development are discussed. Thus the availability of the genome of Musa and the information of TDFs sequences presented here opens new possibilities for an in-depth study of the molecular and biochemical research of zygotic and somatic embryogenesis of Musa. PMID:24027442

Expression of the Hsp23 chaperone during Drosophila embryogenesis: association to distinct neural and glial lineages

PubMed Central

Michaud, Sébastien; Tanguay, Robert M

2003-01-01

Background In addition to their strong induction following stress, small heat shock proteins (Hsp) are also expressed during development in a wide variety of organisms. However, the precise identity of cell(s) expressing these proteins and the functional contribution of small heat shock proteins in such developmental context remain to be determined. The present study provides a detailed description of the Drosophila small heat shock protein Hsp23 expression pattern during embryogenesis and evaluates its functional contribution to central nervous system development. Results Throughout embryogenesis, Hsp23 is expressed in a stage-specific manner by a restricted number of neuronal and glial lineages of the central nervous system. Hsp23 is also detected in the amnioserosa and within a single lateral chordotonal organ. Its expression within the MP2 lineage does not require the presence of a functional midline nor the activity of the Notch signaling pathway. Transactivation assays demonstrate that transcription factors implicated in the differentiation of the midline also regulate hsp23 promoter activity. Phenotypic analysis of a transgenic line exhibiting loss of Hsp23 expression in the central nervous system suggests that Hsp23 is not required for development and function of this tissue. Likewise, its overexpression does not cause deleterious effects, as development remains unaffected. Conclusions Based on the presented data, we suggest that the tightly regulated developmental expression of Hsp23 is not actively involved in cell differentiation and central nervous system development per se but rather reflects a putative role in preventive "pre-stress" neuroprotection or in non-vital process(es) common to the identified cell lineages. PMID:14617383

Genome-wide analysis of transcription factors during somatic embryogenesis in banana (Musa spp.) cv. Grand Naine.

PubMed

Shivani; Awasthi, Praveen; Sharma, Vikrant; Kaur, Navjot; Kaur, Navneet; Pandey, Pankaj; Tiwari, Siddharth

2017-01-01

Transcription factors BABY BOOM (BBM), WUSCHEL (WUS), BSD, LEAFY COTYLEDON (LEC), LEAFY COTYLEDON LIKE (LIL), VIVIPAROUS1 (VP1), CUP SHAPED COTYLEDONS (CUC), BOLITA (BOL), and AGAMOUS LIKE (AGL) play a crucial role in somatic embryogenesis. In this study, we identified eighteen genes of these nine transcription factors families from the banana genome database. All genes were analyzed for their structural features, subcellular, and chromosomal localization. Protein sequence analysis indicated the presence of characteristic conserved domains in these transcription factors. Phylogenetic analysis revealed close evolutionary relationship among most transcription factors of various monocots. The expression patterns of eighteen genes in embryogenic callus containing somatic embryos (precisely isolated by Laser Capture Microdissection), non-embryogenic callus, and cell suspension cultures of banana cultivar Grand Naine were analyzed. The application of 2, 4-dichlorophenoxyacetic acid (2, 4-D) in the callus induction medium enhanced the expression of MaBBM1, MaBBM2, MaWUS2, and MaVP1 in the embryogenic callus. It suggested 2, 4-D acts as an inducer for the expression of these genes. The higher expression of MaBBM2 and MaWUS2 in embryogenic cell suspension (ECS) as compared to non-embryogenic cells suspension (NECS), suggested that these genes may play a crucial role in banana somatic embryogenesis. MaVP1 showed higher expression in both ECS and NECS, whereas MaLEC2 expression was significantly higher in NECS. It suggests that MaLEC2 has a role in the development of non-embryogenic cells. We postulate that MaBBM2 and MaWUS2 can be served as promising molecular markers for the embryogencity in banana.

Genome-wide analysis of transcription factors during somatic embryogenesis in banana (Musa spp.) cv. Grand Naine

PubMed Central

Shivani; Awasthi, Praveen; Sharma, Vikrant; Kaur, Navjot; Kaur, Navneet; Pandey, Pankaj

2017-01-01

Transcription factors BABY BOOM (BBM), WUSCHEL (WUS), BSD, LEAFY COTYLEDON (LEC), LEAFY COTYLEDON LIKE (LIL), VIVIPAROUS1 (VP1), CUP SHAPED COTYLEDONS (CUC), BOLITA (BOL), and AGAMOUS LIKE (AGL) play a crucial role in somatic embryogenesis. In this study, we identified eighteen genes of these nine transcription factors families from the banana genome database. All genes were analyzed for their structural features, subcellular, and chromosomal localization. Protein sequence analysis indicated the presence of characteristic conserved domains in these transcription factors. Phylogenetic analysis revealed close evolutionary relationship among most transcription factors of various monocots. The expression patterns of eighteen genes in embryogenic callus containing somatic embryos (precisely isolated by Laser Capture Microdissection), non-embryogenic callus, and cell suspension cultures of banana cultivar Grand Naine were analyzed. The application of 2, 4-dichlorophenoxyacetic acid (2, 4-D) in the callus induction medium enhanced the expression of MaBBM1, MaBBM2, MaWUS2, and MaVP1 in the embryogenic callus. It suggested 2, 4-D acts as an inducer for the expression of these genes. The higher expression of MaBBM2 and MaWUS2 in embryogenic cell suspension (ECS) as compared to non-embryogenic cells suspension (NECS), suggested that these genes may play a crucial role in banana somatic embryogenesis. MaVP1 showed higher expression in both ECS and NECS, whereas MaLEC2 expression was significantly higher in NECS. It suggests that MaLEC2 has a role in the development of non-embryogenic cells. We postulate that MaBBM2 and MaWUS2 can be served as promising molecular markers for the embryogencity in banana. PMID:28797040

The Pesticide Malathion Disrupts "Xenopus" and Zebrafish Embryogenesis: An Investigative Laboratory Exercise in Developmental Toxicology

ERIC Educational Resources Information Center

Chemotti, Diana C.; Davis, Sarah N.; Cook, Leslie W.; Willoughby, Ian R.; Paradise, Christopher J.; Lom, Barbara

2006-01-01

Malathion is an organophosphorus insecticide, which is often sprayed to control mosquitoes. When applied to aquatic habitats, malathion can also influence the embryogenesis of non-target organisms such as frogs and fish. We modified the frog embryo teratogen assay in "Xenopus" (FETAX), a standard toxicological assay, into an investigative…

Calcium-Mediated Signaling during Sandalwood Somatic Embryogenesis. Role for Exogenous Calcium as Second Messenger1

PubMed Central

Anil, Veena S.; Rao, K. Sankara

2000-01-01

The possible involvement of Ca2+-mediated signaling in the induction/regulation of somatic embryogenesis from pro-embryogenic cells of sandalwood (Santalum album) has been investigated. 45Ca2+-uptake studies and fura-2 fluorescence ratio photometry were used to measure changes in [Ca2+]cyt of pro-embryogenic cells in response to culture conditions conducive for embryo development. Sandalwood pro-embryogenic cell masses (PEMs) are obtained in the callus proliferation medium that contains the auxin 2,4-dichlorophenoxyacetic acid. Subculture of PEMs into the embryo differentiation medium, which lacks 2,4-dichlorophenoxyacetic acid and has higher osmoticum, results in a 4-fold higher 45Ca2+ incorporation into the symplast. Fura-2 ratiometric analysis corroboratively shows a 10- to 16-fold increase in the [Ca2+]cyt of PEMs, increasing from a resting concentration of 30 to 50 nm to 650 to 800 nm. Chelation of exogenous Ca2+ with ethyleneglycol-bis(aminoethyl ether)-N,N′-tetraacetic acid arrests such an elevation in [Ca2+]cyt. Exogenous Ca2+ when chelated or deprived also arrests embryo development and inhibits the accumulation of a sandalwood Ca2+-dependent protein kinase. However, such culture conditions do not cause cell death as the PEMs continue to proliferate to form larger cell clumps. Culture treatment with N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide reduced embryogenic frequency by 85%, indicating that blockage of Ca2+-mediated signaling pathway(s) involving sandalwood Ca2+-dependent protein kinase and/or calmodulin causes the inhibition of embryogenesis. The observations presented are evidence to suggest a second messenger role for exogenous Ca2+ during sandalwood somatic embryogenesis. PMID:10938349

Protocol for in vitro somatic embryogenesis and regeneration of rice (Oryza sativa L.).

PubMed

Verma, Dipti; Joshi, Rohit; Shukla, Alok; Kumar, Pramod

2011-12-01

Development of highly efficient and reproducible plant regeneration system has tremendous potential to provide improved technology to assist in genetic transformation of indica rice cultivars for their further exploitation in selection. For the development of a highly reproducible regeneration system through somatic embryogenesis, mature embryos of highly popular rice cultivars i.e., Govind (for rainfed areas), Pusa Basmati-1 (aromatic basmati) and Jaya (for irrigated areas) were used. Optimum callus formation (%) to MS medium supplemented with 2, 4-D was obtained at 12.0 microM in Govind, 14.0 microM in Jaya and 15.0 microM in Pusa Basmati-1. All the cultivars showed good proliferation on MS medium without hormone. In Govind, highest embryogenic response was observed in MS medium supplemented with 2, 4-D (0.4 microM) + kinetin (0.4 microM), while in Pusa Basmati-1 with 2, 4-D (0.4 microM) + kinetin (2.0 microM) and in Jaya on hormone-free MS medium. Excellent embryo regeneration in Govind was observed on MS medium supplemented with low concentrations (1.1 microM) of BAP or hormone-free MS medium, while in Pusa Basmati-1 and Jaya embryogenesis was observed on MS medium supplemented with higher concentration of BAP (2.2 microM). Similarly, maximum plantlets with proliferated roots were observed in Govind on hormone-free MS medium, while in Pusa Basmati-1 and Jaya on MS medium supplemented with high concentration of NAA (4.0 microM). Developed plantlets were further successfully acclimatized and grown under pot culture up to maturity. Further the yield potential of in vitro developed plants was accessed at par to the direct seeded one under pot culture. Present, protocol standardizes somatic embryogenesis and efficient regeneration of agronomically important, high yielding and diverse indica rice cultivars which can be utilized as an efficient tool for molecular studies and genetic transformation in future.

Ultra-deep sequencing of ribosome-associated poly-adenylated RNA in early Drosophila embryos reveals hundreds of conserved translated sORFs.

PubMed

Li, Hongmei; Hu, Chuansheng; Bai, Ling; Li, Hua; Li, Mingfa; Zhao, Xiaodong; Czajkowsky, Daniel M; Shao, Zhifeng

2016-12-01

There is growing recognition that small open reading frames (sORFs) encoding peptides shorter than 100 amino acids are an important class of functional elements in the eukaryotic genome, with several already identified to play critical roles in growth, development, and disease. However, our understanding of their biological importance has been hindered owing to the significant technical challenges limiting their annotation. Here we combined ultra-deep sequencing of ribosome-associated poly-adenylated RNAs with rigorous conservation analysis to identify a comprehensive population of translated sORFs during early Drosophila embryogenesis. In total, we identify 399 sORFs, including those previously annotated but without evidence of translational capacity, those found within transcripts previously classified as non-coding, and those not previously known to be transcribed. Further, we find, for the first time, evidence for translation of many sORFs with different isoforms, suggesting their regulation is as complex as longer ORFs. Furthermore, many sORFs are found not associated with ribosomes in late-stage Drosophila S2 cells, suggesting that many of the translated sORFs may have stage-specific functions during embryogenesis. These results thus provide the first comprehensive annotation of the sORFs present during early Drosophila embryogenesis, a necessary basis for a detailed delineation of their function in embryogenesis and other biological processes. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Late-Notice HIE Investigation

NASA Technical Reports Server (NTRS)

Hejduk, M. D.

2016-01-01

Provide a response to MOWG action item 1410-01: Analyze close approaches which have required mission team action on short notice. Determine why the approaches were identified later in the process than most other events. Method: Performed an analysis to determine whether there is any correlation between late notice event identification and space weather, sparse tracking, or high drag objects, which would allow preventive action to be taken Examined specific late notice events identified by missions as problematic to try to identify root cause and attempt to relate them to the correlation analysis.

Tandem mass spectrometry, but not T-cell receptor excision circle analysis, identifies newborns with late-onset adenosine deaminase deficiency.

PubMed

la Marca, Giancarlo; Canessa, Clementina; Giocaliere, Elisa; Romano, Francesca; Duse, Marzia; Malvagia, Sabrina; Lippi, Francesca; Funghini, Silvia; Bianchi, Leila; Della Bona, Maria Luisa; Valleriani, Claudia; Ombrone, Daniela; Moriondo, Maria; Villanelli, Fabio; Speckmann, Carsten; Adams, Stuart; Gaspar, Bobby H; Hershfield, Michael; Santisteban, Ines; Fairbanks, Lynette; Ragusa, Giovanni; Resti, Massimo; de Martino, Maurizio; Guerrini, Renzo; Azzari, Chiara

2013-06-01

Adenosine deaminase (ADA)-severe combined immunodeficiency (SCID) is caused by genetic variants that disrupt the function of ADA. In its early-onset form, it is rapidly fatal to infants. Delayed or late-onset ADA-SCID is characterized by insidious progressive immunodeficiency that leads to permanent organ damage or death. Quantification of T-cell receptor excision circles (TRECs) or tandem mass spectrometry (tandem-MS) analysis of dried blood spots (DBSs) collected at birth can identify newborns with early-onset ADA-SCID and are used in screening programs. However, it is not clear whether these analyses can identify newborns who will have delayed or late-onset ADA-SCID before symptoms appear. We performed a retrospective study to evaluate whether tandem-MS and quantitative TREC analyses of DBSs could identify newborns who had delayed-onset ADA-SCID later in life. We tested stored DBSs collected at birth from 3 patients with delayed-onset ADA-SCID using tandem-MS (PCT EP2010/070517) to evaluate levels of adenosine and 2'-deoxyadenosine and real-time PCR to quantify TREC levels. We also analyzed DBSs from 3 newborns with early-onset ADA-SCID and 2 healthy newborn carriers of ADA deficiency. The DBSs taken at birth from the 3 patients with delayed-onset ADA-SCID had adenosine levels of 10, 25, and 19 μmol/L (normal value, <1.5 μmol/L) and 2'-deoxyadenosine levels of 0.7, 2.7, and 2.4 μmol/L (normal value, <0.07 μmol/L); the mean levels of adenosine and 2'-deoxyadenosine were respectively 12.0- and 27.6-fold higher than normal values. DBSs taken at birth from all 3 patients with delayed-onset ADA deficiency had normal TREC levels, but TRECs were undetectable in blood samples taken from the same patients at the time of diagnosis. Tandem-MS but not TREC quantification identifies newborns with delayed- or late-onset ADA deficiency. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Oil body biogenesis during Brassica napus embryogenesis.

PubMed

He, Yu-Qing; Wu, Yan

2009-08-01

Although the oil body is known to be an important membrane enclosed compartment for oil storage in seeds, we have little understanding about its biogenesis during embryogenesis. In the present study we investigated the oil body emergence and variations in Brassica napus cv. Topas. The results demonstrate that the oil bodies could be detected already at the heart stage, at the same time as the embryos began to turn green, and the starch grains accumulated in the chloroplast stroma. In comparison, we have studied the development of oil bodies between Arabidopsis thaliana wild type (Col) and the low-seed-oil mutant wrinkled1-3. We observed that the oil body development in the embryos of Col is similar to that of B. napus cv. Topas, and that the size of the oil bodies was obviously smaller in the embryos of wrinkled1-3. Our results suggest that the oil body biogenesis might be coupled with the embryo chloroplast.

Non-staining visualization of embryogenesis and energy metabolism in medaka fish eggs using near-infrared spectroscopy and imaging.

PubMed

Puangchit, Paralee; Ishigaki, Mika; Yasui, Yui; Kajita, Misato; Ritthiruangdej, Pitiporn; Ozaki, Yukihiro

2017-12-04

The energy metabolism and embryogenesis of fertilized Japanese medaka eggs were investigated in vivo at the molecular level using near-infrared (NIR) spectroscopy and imaging. Changes in chemical components, such as proteins and lipids, in yolk sphere and embryonic body were studied over the course of embryonic development. Metabolic changes that represent variations in the concentrations and molecular compositions of proteins and lipids in the yolk part, particularly on the 1 st day after fertilization and the day just before hatching, were successfully identified in the 4900-4000 cm -1 wavenumber region. The yolk components were shown to have specific functions at the very early and final stages of the embryonic development. Proteins with α-helix- or β-sheet-rich structures clearly showed the different variation patterns within the developing egg. Furthermore, the distribution of lipids could be selectively visualized using data from the higher wavenumber region. Detailed embryonic structures were clearly depicted in the NIR images using the data from the 6400-5500 cm -1 region in which the embryo parts had some characteristic peaks due to unsaturated fatty acids. It was made clear that yolk and embryo parts had different components especially lipid components. The present study provides new insights into material variations in the fertilized egg during its growth. NIR imaging proved to be valuable in investigating the embryogenesis in vivo at the molecular level in terms of changes in biomolecular concentrations and compositions, metabolic differentiation, and detailed information about embryonic structures without the need for staining.

Collective Cell Migration in Embryogenesis Follows the Laws of Wetting.

PubMed

Wallmeyer, Bernhard; Trinschek, Sarah; Yigit, Sargon; Thiele, Uwe; Betz, Timo

2018-01-09

Collective cell migration is a fundamental process during embryogenesis and its initial occurrence, called epiboly, is an excellent in vivo model to study the physical processes involved in collective cell movements that are key to understanding organ formation, cancer invasion, and wound healing. In zebrafish, epiboly starts with a cluster of cells at one pole of the spherical embryo. These cells are actively spreading in a continuous movement toward its other pole until they fully cover the yolk. Inspired by the physics of wetting, we determine the contact angle between the cells and the yolk during epiboly. By choosing a wetting approach, the relevant scale for this investigation is the tissue level, which is in contrast to other recent work. Similar to the case of a liquid drop on a surface, one observes three interfaces that carry mechanical tension. Assuming that interfacial force balance holds during the quasi-static spreading process, we employ the physics of wetting to predict the temporal change of the contact angle. Although the experimental values vary dramatically, the model allows us to rescale all measured contact-angle dynamics onto a single master curve explaining the collective cell movement. Thus, we describe the fundamental and complex developmental mechanism at the onset of embryogenesis by only three main parameters: the offset tension strength, α, that gives the strength of interfacial tension compared to other force-generating mechanisms; the tension ratio, δ, between the different interfaces; and the rate of tension variation, λ, which determines the timescale of the whole process. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Deconstructing cartilage shape and size into contributions from embryogenesis, metamorphosis, and tadpole and frog growth.

PubMed

Rose, Christopher S; Murawinski, Danny; Horne, Virginia

2015-06-01

Understanding skeletal diversification involves knowing not only how skeletal rudiments are shaped embryonically, but also how skeletal shape changes throughout life. The pharyngeal arch (PA) skeleton of metamorphosing amphibians persists largely as cartilage and undergoes two phases of development (embryogenesis and metamorphosis) and two phases of growth (larval and post-metamorphic). Though embryogenesis and metamorphosis produce species-specific features of PA cartilage shape, the extents to which shape and size change during growth and metamorphosis remain unaddressed. This study uses allometric equations and thin-plate spline, relative warp and elliptic Fourier analyses to describe shape and size trajectories for the ventral PA cartilages of the frog Xenopus laevis in tadpole and frog growth and metamorphosis. Cartilage sizes scale negatively with body size in both growth phases and cartilage shapes scale isometrically or close to it. This implies that most species-specific aspects of cartilage shape arise in embryogenesis and metamorphosis. Contributions from growth are limited to minor changes in lower jaw (LJ) curvature that produce relative gape narrowing and widening in tadpoles and frogs, respectively, and most cartilages becoming relatively thinner. Metamorphosis involves previously unreported decreases in cartilage size as well as changes in cartilage shape. The LJ becomes slightly longer, narrower and more curved, and the adult ceratohyal emerges from deep within the resorbing tadpole ceratohyal. This contrast in shape and size changes suggests a fundamental difference in the underlying cellular pathways. The observation that variation in PA cartilage shape decreases with tadpole growth supports the hypothesis that isometric growth is required for the metamorphic remodeling of PA cartilages. It also supports the existence of shape-regulating mechanisms that are specific to PA cartilages and that resist local adaptation and phenotypic plasticity. �

Deconstructing cartilage shape and size into contributions from embryogenesis, metamorphosis, and tadpole and frog growth

PubMed Central

Rose, Christopher S; Murawinski, Danny; Horne, Virginia

2015-01-01

Understanding skeletal diversification involves knowing not only how skeletal rudiments are shaped embryonically, but also how skeletal shape changes throughout life. The pharyngeal arch (PA) skeleton of metamorphosing amphibians persists largely as cartilage and undergoes two phases of development (embryogenesis and metamorphosis) and two phases of growth (larval and post-metamorphic). Though embryogenesis and metamorphosis produce species-specific features of PA cartilage shape, the extents to which shape and size change during growth and metamorphosis remain unaddressed. This study uses allometric equations and thin-plate spline, relative warp and elliptic Fourier analyses to describe shape and size trajectories for the ventral PA cartilages of the frog Xenopus laevis in tadpole and frog growth and metamorphosis. Cartilage sizes scale negatively with body size in both growth phases and cartilage shapes scale isometrically or close to it. This implies that most species-specific aspects of cartilage shape arise in embryogenesis and metamorphosis. Contributions from growth are limited to minor changes in lower jaw (LJ) curvature that produce relative gape narrowing and widening in tadpoles and frogs, respectively, and most cartilages becoming relatively thinner. Metamorphosis involves previously unreported decreases in cartilage size as well as changes in cartilage shape. The LJ becomes slightly longer, narrower and more curved, and the adult ceratohyal emerges from deep within the resorbing tadpole ceratohyal. This contrast in shape and size changes suggests a fundamental difference in the underlying cellular pathways. The observation that variation in PA cartilage shape decreases with tadpole growth supports the hypothesis that isometric growth is required for the metamorphic remodeling of PA cartilages. It also supports the existence of shape-regulating mechanisms that are specific to PA cartilages and that resist local adaptation and phenotypic plasticity. PMID

Wild worm embryogenesis harbors ubiquitous polygenic modifier variation.

PubMed

Paaby, Annalise B; White, Amelia G; Riccardi, David D; Gunsalus, Kristin C; Piano, Fabio; Rockman, Matthew V

2015-08-22

Embryogenesis is an essential and stereotypic process that nevertheless evolves among species. Its essentiality may favor the accumulation of cryptic genetic variation (CGV) that has no effect in the wild-type but that enhances or suppresses the effects of rare disruptions to gene function. Here, we adapted a classical modifier screen to interrogate the alleles segregating in natural populations of Caenorhabditis elegans: we induced gene knockdowns and used quantitative genetic methodology to examine how segregating variants modify the penetrance of embryonic lethality. Each perturbation revealed CGV, indicating that wild-type genomes harbor myriad genetic modifiers that may have little effect individually but which in aggregate can dramatically influence penetrance. Phenotypes were mediated by many modifiers, indicating high polygenicity, but the alleles tend to act very specifically, indicating low pleiotropy. Our findings demonstrate the extent of conditional functionality in complex trait architecture.

Influence of low temperature preincubation on somatic embryogenesis and ethylene emanation from orchardgrass leaves

NASA Technical Reports Server (NTRS)

Tomaszewski, Z. Jr; Kuklin, A. I.; Sams, C. E.; Conger, B. V.

1994-01-01

The objectives of this study were to determine the effects of low temperature (4 degrees C) preincubation on somatic embryogenesis from orchardgrass (Dactylis glomerata L.) leaf cultures and to relate these effects to ethylene emanation during the preincubation and incubation periods. Experiments were also conducted with an ethylene biosynthesis inhibitor aminooxyacetic acid (AOA). Segments from the innermost two leaves were cultured on SH medium with 30 micromoles dicamba at 4 degrees C for 1 to 7 d before transfer to 21 degrees C. Results from a paired design showed that the embryogenic response of leaf segments preincubated at 4 degrees C was equal or superior to nonpreincubated leaves at all time periods. Ethylene emanation was decreased during the low temperature incubation. Transfer of leaf segments from 4 degrees C to 21 degrees C was accompanied by a burst of ethylene which rose to control levels within 30 min. AOA at 20 and 40 micromoles decreased ethylene emanation but did not stimulate the embryogenic response. We conclude that the stimulation of somatic embryogenesis by low temperature is probably due to factors other than suppression of ethylene biosynthesis.

Differential expression of two scribble isoforms during Drosophila embryogenesis.

PubMed

Li, M; Marhold, J; Gatos, A; Török, I; Mechler, B M

2001-10-01

The tumour suppressor gene scribble (scrib) is required for epithelial polarity and growth control in Drosophila. Here, we report the identification and embryonic expression pattern of two Scrib protein isoforms resulting from alternative splicing during scrib transcription. Both proteins are first ubiquitously expressed during early embryogenesis. Then, during morphogenesis each Scrib protein displays a specific pattern of expression in the central and peripheral nervous systems, CNS and PNS, respectively. During germ band extension, the expression of the longer form Scrib1 occurs predominantly in the neuroblasts derived from the neuro-ectoderm and becomes later restricted to CNS neurones as well as to the pole cells in the gonads. By contrast, the shorter form Scrib2 is strongly expressed in the PNS and a subset of CNS neurones.

Tissue specific characterisation of Lim-kinase 1 expression during mouse embryogenesis

PubMed Central

Lindström, Nils O.; Neves, Carlos; McIntosh, Rebecca; Miedzybrodzka, Zosia; Vargesson, Neil; Collinson, J. Martin

2012-01-01

The Lim-kinase (LIMK) proteins are important for the regulation of the actin cytoskeleton, in particular the control of actin nucleation and depolymerisation via regulation of cofilin, and hence may control a large number of processes during development, including cell tensegrity, migration, cell cycling, and axon guidance. LIMK1/LIMK2 knockouts disrupt spinal cord morphogenesis and synapse formation but other tissues and developmental processes that require LIMK are yet to be fully determined. To identify tissues and cell-types that may require LIMK, we characterised the pattern of LIMK1 protein during mouse embryogenesis. We showed that LIMK1 displays an expression pattern that is temporally dynamic and tissue-specific. In several tissues LIMK1 is detected in cell-types that also express Wilms’ tumour protein 1 and that undergo transitions between epithelial and mesenchymal states, including the pleura, epicardium, kidney nephrons, and gonads. LIMK1 was also found in a subset of cells in the dorsal retina, and in mesenchymal cells surrounding the peripheral nerves. This detailed study of the spatial and temporal expression of LIMK1 shows that LIMK1 expression is more dynamic than previously reported, in particular at sites of tissue–tissue interactions guiding multiple developmental processes. PMID:21167960

Gametic embryogenesis and haploid technology as valuable support to plant breeding.

PubMed

Germanà, Maria Antonietta

2011-05-01

Plant breeding is focused on continuously increasing crop production to meet the needs of an ever-growing world population, improving food quality to ensure a long and healthy life and address the problems of global warming and environment pollution, together with the challenges of developing novel sources of biofuels. The breeders' search for novel genetic combinations, with which to select plants with improved traits to satisfy both farmers and consumers, is endless. About half of the dramatic increase in crop yield obtained in the second half of the last century has been achieved thanks to the results of genetic improvement, while the residual advance has been due to the enhanced management techniques (pest and disease control, fertilization, and irrigation). Biotechnologies provide powerful tools for plant breeding, and among these ones, tissue culture, particularly haploid and doubled haploid technology, can effectively help to select superior plants. In fact, haploids (Hs), which are plants with gametophytic chromosome number, and doubled haploids (DHs), which are haploids that have undergone chromosome duplication, represent a particularly attractive biotechnological method to accelerate plant breeding. Currently, haploid technology, making possible through gametic embryogenesis the single-step development of complete homozygous lines from heterozygous parents, has already had a huge impact on agricultural systems of many agronomically important crops, representing an integral part in their improvement programmes. The aim of this review was to provide some background, recent advances, and future prospective on the employment of haploid technology through gametic embryogenesis as a powerful tool to support plant breeding.

Desiccation Treatment and Endogenous IAA Levels Are Key Factors Influencing High Frequency Somatic Embryogenesis in Cunninghamia lanceolata (Lamb.) Hook

PubMed Central

Zhou, Xiaohong; Zheng, Renhua; Liu, Guangxin; Xu, Yang; Zhou, Yanwei; Laux, Thomas; Zhen, Yan; Harding, Scott A.; Shi, Jisen; Chen, Jinhui

2017-01-01

Cunninghamia lanceolata (Lamb.) Hook (Chinese fir) is an important tree, commercially and ecologically, in southern China. The traditional regenerating methods are based on organogenesis and cutting propagation. Here, we report the development of a high-frequency somatic embryogenesis (SE) regeneration system synchronized via a liquid culture from immature zygotic embryos. Following synchronization, PEM II cell aggregates were developmentally equivalent in appearance to cleaved zygotic embryos. Embryo and suspensor growth and subsequent occurrence of the apical and then the cotyledonary meristems were similar for zygotic and SE embryo development. However, SE proembryos exhibited a more reddish coloration than zygotic proembryos, and SE embryos were smaller than zygotic embryos. Mature somatic embryos gave rise to plantlets on hormone-free medium. For juvenile explants, low concentrations of endogenous indole-3-acetic acid in initial explants correlated with improved proembryogenic mass formation, and high SE competency. Analysis of karyotypes and microsatellites detected no major genetic variation in the plants regenerated via SE, and suggest a potential in the further development of this system as a reliable methodology for true-to-type seedling production. Treatment with polyethylene glycol (PEG) and abscisic acid (ABA) were of great importance to proembryo formation and complemented each other. ABA assisted the growth of embryonal masses, whereas PEG facilitated the organization of the proembryo-like structures. SOMATIC EMBRYOGENESIS RECEPTOR KINASE SERK) and the WUSCHEL homeobox (WOX) transcription factor served as molecular markers during early embryogenesis. Our results show that ClSERKs are conserved and redundantly expressed during SE. SERK and WOX transcript levels were highest during development of the proembryos and lowest in developed embryos. ClWOX13 expression correlates with the critical transition from proembryogenic masses to proembryos. Both SERK

Extrinsic Embryonic Sensory Stimulation Alters Multimodal Behavior and Cellular Activation

PubMed Central

Markham, Rebecca G.; Shimizu, Toru; Lickliter, Robert

2009-01-01

Embryonic vision is generated and maintained by spontaneous neuronal activation patterns, yet extrinsic stimulation also sculpts sensory development. Because the sensory and motor systems are interconnected in embryogenesis, how extrinsic sensory activation guides multimodal differentiation is an important topic. Further, it is unknown whether extrinsic stimulation experienced near sensory sensitivity onset contributes to persistent brain changes, ultimately affecting postnatal behavior. To determine the effects of extrinsic stimulation on multimodal development, we delivered auditory stimulation to bobwhite quail groups during early, middle, or late embryogenesis, and then tested postnatal behavioral responsiveness to auditory or visual cues. Auditory preference tendencies were more consistently toward the conspecific stimulus for animals stimulated during late embryogenesis. Groups stimulated during middle or late embryogenesis showed altered postnatal species-typical visual responsiveness, demonstrating a persistent multimodal effect. We also examined whether auditory-related brain regions are receptive to extrinsic input during middle embryogenesis by measuring postnatal cellular activation. Stimulated birds showed a greater number of ZENK-immunopositive cells per unit volume of brain tissue in deep optic tectum, a midbrain region strongly implicated in multimodal function. We observed similar results in the medial and caudomedial nidopallia in the telencephalon. There were no ZENK differences between groups in inferior colliculus or in caudolateral nidopallium, avian analog to prefrontal cortex. To our knowledge, these are the first results linking extrinsic stimulation delivered so early in embryogenesis to changes in postnatal multimodal behavior and cellular activation. The potential role of competitive interactions between the sensory and motor systems is discussed. PMID:18777564

Somatic embryogenesis from corolla tubes of interspecific amphiploids between cultivated sunflower (Helianthus annuus L.) and its wild species

USDA-ARS?s Scientific Manuscript database

Somatic embryogenesis in vitro provides an efficient means of plant multiplication, facilitating sunflower improvement and germplasm innovation. In the present study, using interspecific amphiploids (2n=4x=68) between cultivated sunflower and wild perennial Helianthus species as explant donors, soma...

Micropropagation of Citrus spp. by organogenesis and somatic embryogenesis.

PubMed

Chiancone, Benedetta; Germanà, Maria Antonietta

2013-01-01

Citrus spp., the largest fruit crops produced worldwide, are usually asexually propagated by cuttings or grafting onto seedling rootstocks. Most of Citrus genotypes are characterized by polyembryony due to the occurrence of adventive nucellar embryos, which lead to the production of true-to-type plants by seed germination. Tissue culture and micropropagation, in particular, are valuable alternatives to traditional propagation to obtain a high number of uniform and healthy plants in a short time and in a small space. Moreover, in vitro propagation provides a rapid system to multiply the progeny obtained by breeding programs, allows the use of monoembryonic and seedless genotypes as rootstocks, and it is very useful also for breeding and germplasm preservation.In this chapter, two protocols regarding organogenesis of a rootstock and somatic embryogenesis of a cultivar have been described.

Developmental localization and the role of hydroxyproline rich glycoproteins during somatic embryogenesis of banana (Musa spp. AAA)

PubMed Central

2011-01-01

Background Hydroxyproline rich glycoproteins (HRGPs) are implicated to have a role in many aspects of plant growth and development but there is limited knowledge about their localization and function during somatic embryogenesis of higher plants. In this study, the localization and function of hydroxyproline rich glycoproteins in embryogenic cells (ECs) and somatic embryos of banana were investigated by using immunobloting and immunocytochemistry with monoclonal JIM11 and JIM20 antibodies as well as by treatment with 3,4-dehydro-L-proline (3,4-DHP, an inhibitor of extensin biosynthesis), and by immunomodulation with the JIM11 antibody. Results Immunofluorescence labelling of JIM11 and JIM20 hydroxyproline rich glycoprotein epitopes was relatively weak in non-embryogenic cells (NECs), mainly on the edge of small cell aggregates. On the other hand, hydroxyproline rich glycoprotein epitopes were found to be enriched in early embryogenic cells as well as in various developmental stages of somatic embryos. Embryogenic cells (ECs), proembryos and globular embryos showed strong labelling of hydroxyproline rich glycoprotein epitopes, especially in their cell walls and outer surface layer, so-called extracellular matrix (ECM). This hydroxyproline rich glycoprotein signal at embryo surfaces decreased and/or fully disappeared during later developmental stages (e.g. pear-shaped and cotyledonary stages) of embryos. In these later developmental embryogenic stages, however, new prominent hydroxyproline rich glycoprotein labelling appeared in tri-cellular junctions among parenchymatic cells inside these embryos. Overall immunofluorescence labelling of late stage embryos with JIM20 antibody was weaker than that of JIM11. Western blot analysis supported the above immunolocalization data. The treatment with 3,4-DHP inhibited the development of embryogenic cells and decreased the rate of embryo germination. Embryo-like structures, which developed after 3,4-DHP treatment showed

The pathology of lumbosacral lipomas: macroscopic and microscopic disparity have implications for embryogenesis and mode of clinical deterioration.

PubMed

Jones, Victoria; Wykes, Victoria; Cohen, Nicki; Thompson, Dominic; Jacques, Tom S

2018-06-01

Lumbosacral lipomas (LSL) are congenital disorders of the terminal spinal cord region that have the potential to cause significant spinal cord dysfunction in children. They are of unknown embryogenesis with variable clinical presentation and natural history. It is unclear whether the spinal cord dysfunction reflects a primary developmental dysplasia or whether it occurs secondarily to mechanical traction (spinal cord tethering) with growth. While different anatomical subtypes are recognised and classified according to radiological criteria, these subtypes correlate poorly with clinical prognosis. We have undertaken an analysis of surgical specimens in order to describe the spectrum of histological changes that occur and have correlated the histology with the anatomical type of LSL to determine if there are distinct histological subtypes. The histopathology was reviewed of 64 patients who had undergone surgical resection of LSL. The presence of additional tissues and cell types were recorded. LSLs were classified from pre-operative magnetic resonance imaging (MRI) scans according to Chapman classification. Ninety-five per cent of the specimens consisted predominantly of mature adipocytes with all containing thickened bands of connective tissue and peripheral nerve fibres, 91% of samples contained ectatic blood vessels with thickened walls, while 22% contained central nervous system (CNS) glial tissue. Additional tissue was identified of both mesodermal and neuroectodermal origin. Our analysis highlights the heterogeneity of tissue types within all samples, not reflected in the nomenclature. The diversity of tissue types, consistent across all subtypes, challenges currently held notions regarding the embryogenesis of LSLs and the assumption that clinical deterioration is due simply to tethering. © 2018 The Authors. Histopathology Published by John Wiley & Sons Ltd.

Polyamine and ethylene biosynthesis in relation to somatic embryogenesis in carrot (Daucus carota L.) cell cultures

Treesearch

Subhash C. Minocha; Cheryl A. Robie; Akhtar J. Khan; Nancy S. Papa; Andrew I. Samuelsen; Rakesh Minocha

1990-01-01

Carrot cell cultures provide a model experimental system for the analysis of biochemical and molecular events associated with morphogenesis in plants (3, 4, 5, 14). Among the biochemical changes accompanying somatic embryogenesis in this tissue is an increased biosynthesis ofpolyamines (1, 2, 7, 10, 11, 13). A variety of inhibitors of polyamine biosynthetic enzymes...

Essential Dosage-Dependent Functions of the Transcription Factor Yin Yang 1 in Late Embryonic Development and Cell Cycle Progression†

PubMed Central

Affar, El Bachir; Gay, Frédérique; Shi, Yujiang; Liu, Huifei; Huarte, Maite; Wu, Su; Collins, Tucker; Li, En; Shi, Yang

2006-01-01

Constitutive ablation of the Yin Yang 1 (YY1) transcription factor in mice results in peri-implantation lethality. In this study, we used homologous recombination to generate knockout mice carrying yy1 alleles expressing various amounts of YY1. Phenotypic analysis of yy1 mutant embryos expressing ∼75%, ∼50%, and ∼25% of the normal complement of YY1 identified a dosage-dependent requirement for YY1 during late embryogenesis. Indeed, reduction of YY1 levels impairs embryonic growth and viability in a dose-dependent manner. Analysis of the corresponding mouse embryonic fibroblast cells also revealed a tight correlation between YY1 dosage and cell proliferation, with a complete ablation of YY1 inducing cytokinesis failure and cell cycle arrest. Consistently, RNA interference-mediated inhibition of YY1 in HeLa cells prevents cytokinesis, causes proliferative arrest, and increases cellular sensitivity to various apoptotic agents. Genome-wide expression profiling identified a plethora of YY1 target genes that have been implicated in cell growth, proliferation, cytokinesis, apoptosis, development, and differentiation, suggesting that YY1 coordinates multiple essential biological processes through a complex transcriptional network. These data not only shed new light on the molecular basis for YY1 developmental roles and cellular functions, but also provide insight into the general mechanisms controlling eukaryotic cell proliferation, apoptosis, and differentiation. PMID:16611997

Dual specificity of activin type II receptor ActRIIb in dorso-ventral patterning during zebrafish embryogenesis.

PubMed

Nagaso, H; Suzuki, A; Tada, M; Ueno, N

1999-04-01

Members of the transforming growth factor-beta (TGF-beta) superfamily are thought to regulate specification of a variety of tissue types in early embryogenesis. These effects are mediated through a cell surface receptor complex, consisting of two classes of ser/thr kinase receptor, type I and type II. In the present study, cDNA encoding zebrafish activin type II receptors, ActRIIa and ActRIIb was cloned and characterized. Overexpression of ActRIIb in zebrafish embryos caused dorsalization of embryos, as observed in activin-overexpressing embryos. However, in blastula stage embryos, ActRIIb induced formation of both dorsal and ventro-lateral mesoderm. It has been suggested that these inducing signals from ActRIIb are mediated through each specific type I receptor, TARAM-A and BMPRIA, depending on activin and bone morphogenetic protein (BMP), respectively. In addition, it was shown that a kinase-deleted form of ActRIIb (dnActRIIb) suppressed both activin- and BMP-like signaling pathways. These results suggest that ActRIIb at least has dual roles in both activin and BMP signaling pathways during zebrafish embryogenesis.

Notch1 is asymmetrically distributed from the beginning of embryogenesis and controls the ventral center.

PubMed

Castro Colabianchi, Aitana M; Revinski, Diego R; Encinas, Paula I; Baez, María Verónica; Monti, Renato J; Abinal, Mateo Rodríguez; Kodjabachian, Laurent; Franchini, Lucía F; López, Silvia L

2018-06-04

Based on functional evidence, we have previously demonstrated that an early ventral Notch1 activity restricts dorsoanterior development in Xenopus We found that Notch1 has ventralizing properties and abolishes the dorsalizing activity of β-catenin by reducing its steady state levels, in a process that does not require β-catenin phosphorylation by glycogen synthase kinase-3β. In the present work, we demonstrate that Notch1 mRNA and protein are enriched in the ventral region from the beginning of the embryogenesis in Xenopus This is the earliest sign of ventral development, preceding the localized expression of wnt8a , bmp4 and ventxs genes in the ventral center and the dorsal accumulation of nuclear β-catenin. Knock-down experiments indicate that Notch1 is necessary for the normal expression of genes essential for ventral-posterior development. These results indicate that during early embryogenesis, ventrally located Notch1 promotes the development of the ventral center. Together with our previous evidence, these results suggest that ventral enrichment of Notch1 underlies the process by which Notch1 participates in restricting nuclear accumulation of β-catenin to the dorsal side. © 2018. Published by The Company of Biologists Ltd.

Aquinas's account of human embryogenesis and recent interpretations.

PubMed

Eberl, Jason T

2005-08-01

In addressing bioethical issues at the beginning of human life, such as abortion, in vitro fertilization, and embryonic stem cell research, one primary concern regards establishing when a developing human embryo or fetus can be considered a person. Thomas Aquinas argues that an embryo or fetus is not a human person until its body is informed by a rational soul. Aquinas's explicit account of human embryogenesis has been generally rejected by contemporary scholars due to its dependence upon medieval biological data, which has been far surpassed by current scientific research. A number of scholars, however, have attempted to combine Aquinas's basic metaphysical account of human nature with current embryological data to develop a contemporary Thomistic account of a human person's beginning. In this article, I discuss two recent interpretations in which it is argued that a human person does not begin to exist until a fetus has developed a functioning cerebral cortex.

Wild worm embryogenesis harbors ubiquitous polygenic modifier variation

PubMed Central

Paaby, Annalise B; White, Amelia G; Riccardi, David D; Gunsalus, Kristin C; Piano, Fabio; Rockman, Matthew V

2015-01-01

Embryogenesis is an essential and stereotypic process that nevertheless evolves among species. Its essentiality may favor the accumulation of cryptic genetic variation (CGV) that has no effect in the wild-type but that enhances or suppresses the effects of rare disruptions to gene function. Here, we adapted a classical modifier screen to interrogate the alleles segregating in natural populations of Caenorhabditis elegans: we induced gene knockdowns and used quantitative genetic methodology to examine how segregating variants modify the penetrance of embryonic lethality. Each perturbation revealed CGV, indicating that wild-type genomes harbor myriad genetic modifiers that may have little effect individually but which in aggregate can dramatically influence penetrance. Phenotypes were mediated by many modifiers, indicating high polygenicity, but the alleles tend to act very specifically, indicating low pleiotropy. Our findings demonstrate the extent of conditional functionality in complex trait architecture. DOI: http://dx.doi.org/10.7554/eLife.09178.001 PMID:26297805

New theory of uterovaginal embryogenesis.

PubMed

Makiyan, Zograb

2016-01-02

The explanation of uterine and vaginal embryogenesis in humans still poses many controversies, because it is difficult to assess early stages of an embryo. The literature review revealed many disagreements in Mullerian theory, inciting some authors to propose new embryological hypotheses. In the original Mullerian theory: the paramesonephral ducts form the Fallopian tubes, uterus and vagina; the mesonephral ducts regress in female embryos. The aim of this article is to investigate the development of Mullerian ducts in humans, using comparative analysis of fundamental embryological theory and various utero-vaginal anomalies. Between 1998 and 2015, 434 patients with various uterovaginal malformations had been operated on at the Scientific Centre of Obstetrics Gynaecology and Perynatology in Moscow. The anatomies of the uterovaginal malformations in these patients were diagnosed with ultrasound and MRI and then verified during surgical correction by laparoscopy. A systematic comparison of uterovaginal malformations to those in the literature has allowed us to formulate a new theory of embryonic morphogenesis. The new theory is significantly different: ovary, ovarian ligamentum proprium, and ligamentum teres uteri derive from gonadal ridges; Fallopian tubes and vagina completely develop from mesonephral ducts. The uterus develops in the area of intersection between the mesonephral ducts with gonadal ridges by the fusion of the two. The new theory may to induce future embryological studies. The hypothetic possibility that the ovary and endometrium derive from the gonadal ridges could be the key to understanding the enigmatic aetiologies of extragenital and ovarian endometriosis.

QTL-seq approach identified genomic regions and diagnostic markers for rust and late leaf spot resistance in groundnut (Arachis hypogaea L.)

USDA-ARS?s Scientific Manuscript database

Rust and late leaf spot (LLS) are the two major foliar fungal diseases in groundnut, and their co-occurrence leads to yield loss up to 50–70% in addition to the deterioration of fodder quality. To identify candidate genomic regions controlling rust and LLS resistance, we deployed whole genome re-seq...

Identifying bvFTD Within the Wide Spectrum of Late Onset Frontal Lobe Syndrome: A Clinical Approach.

PubMed

Krudop, Welmoed A; Kerssens, Cora J; Dols, Annemiek; Prins, Niels D; Möller, Christiane; Schouws, Sigfried; van der Flier, Wiesje M; Scheltens, Philip; Sikkes, Sietske; Stek, Max L; Pijnenburg, Yolande A L

2015-10-01

The behavioral variant of frontotemporal dementia (bvFTD) can be difficult to diagnose because of the extensive differential diagnosis, including many other diseases presenting with a frontal lobe syndrome. We aimed to identify the diagnostic spectrum causing a late onset frontal lobe syndrome and examine the quality of commonly used instruments to distinguish between bvFTD and non-bvFTD patients, within this syndrome. A total of 137 patients fulfilling the criteria of late onset frontal lobe syndrome, aged 45 to 75 years, were included in a prospective observational study. Diagnoses were made after clinical and neuropsychological examination, and neuroimaging and cerebral spinal fluid results were taken into account. Baseline characteristics and the scores on the Mini-Mental State Exam (MMSE), frontal assessment battery (FAB), Frontal Behavioral Inventory (FBI), and Stereotypy Rating Inventory (SRI) were compared between the bvFTD and the non-bvFTD group. Fifty-five (40%) of the patients received a bvFTD diagnosis (33% probable and 7% possible bvFTD). Fifty-one patients (37%) had a psychiatric disorder, including 20 with major depressive disorder. Thirty-one patients received an alternative neurological, including neurodegenerative, diagnosis. MMSE and FAB scores were unspecific for a particular diagnosis. A score above 12 on the positive FBI subscale or a score above 5 on the SRI were indicative of a bvFTD diagnosis. A broad spectrum of both neurological and psychiatric disorders underlies late onset frontal lobe syndrome, of which bvFTD was the most prevalent diagnosis in our cohort. The commonly used MMSE and the FAB could not successfully distinguish between bvFTD and non-bvFTD, but this could be achieved with the more specific FBI and SRI. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Zebrafish E-cadherin: expression during early embryogenesis and regulation during brain development.

PubMed

Babb, S G; Barnett, J; Doedens, A L; Cobb, N; Liu, Q; Sorkin, B C; Yelick, P C; Raymond, P A; Marrs, J A

2001-06-01

Zebrafish E-cadherin (cdh1) cell adhesion molecule cDNAs were cloned. We investigated spatial and temporal expression of cdh1 during early embryogenesis. Expression was observed in blastomeres, the anterior mesoderm during gastrulation, and developing epithelial structures. In the developing nervous system, cdh1 was detected at the pharyngula stage (24 hpf) in the midbrain-hindbrain boundary (MHB). Developmental regulation of MHB formation involves wnt1 and pax2.1. wnt1 expression preceded cdh1 expression during MHB formation, and cdh1 expression in the MHB was dependent on normal development of this structure. Copyright 2001 Wiley-Liss, Inc.

Linkage analyses in Caribbean Hispanic families identify novel loci associated with familial late-onset Alzheimer's disease.

PubMed

Barral, Sandra; Cheng, Rong; Reitz, Christiane; Vardarajan, Badri; Lee, Joseph; Kunkle, Brian; Beecham, Gary; Cantwell, Laura S; Pericak-Vance, Margaret A; Farrer, Lindsay A; Haines, Jonathan L; Goate, Alison M; Foroud, Tatiana; Boerwinkle, Eric; Schellenberg, Gerard D; Mayeux, Richard

2015-12-01

We performed linkage analyses in Caribbean Hispanic families with multiple late-onset Alzheimer's disease (LOAD) cases to identify regions that may contain disease causative variants. We selected 67 LOAD families to perform genome-wide linkage scan. Analysis of the linked regions was repeated using the entire sample of 282 families. Validated chromosomal regions were analyzed using joint linkage and association. We identified 26 regions linked to LOAD (HLOD ≥3.6). We validated 13 of the regions (HLOD ≥2.5) using the entire family sample. The strongest signal was at 11q12.3 (rs2232932: HLODmax = 4.7, Pjoint = 6.6 × 10(-6)), a locus located ∼2 Mb upstream of the membrane-spanning 4A gene cluster. We additionally identified a locus at 7p14.3 (rs10255835: HLODmax = 4.9, Pjoint = 1.2 × 10(-5)), a region harboring genes associated with the nervous system (GARS, GHRHR, and NEUROD6). Future sequencing efforts should focus on these regions because they may harbor familial LOAD causative mutations. Copyright © 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Enhancer of zeste acts as a major developmental regulator of Ciona intestinalis embryogenesis

PubMed Central

Le Goff, Emilie; Martinand-Mari, Camille; Martin, Marianne; Feuillard, Jérôme; Boublik, Yvan; Godefroy, Nelly; Mangeat, Paul; Baghdiguian, Stephen; Cavalli, Giacomo

2015-01-01

ABSTRACT The paradigm of developmental regulation by Polycomb group (PcG) proteins posits that they maintain silencing outside the spatial expression domains of their target genes, particularly of Hox genes, starting from mid embryogenesis. The Enhancer of zeste [E(z)] PcG protein is the catalytic subunit of the PRC2 complex, which silences its targets via deposition of the H3K27me3 mark. Here, we studied the ascidian Ciona intestinalis counterpart of E(z). Ci-E(z) is detected by immunohistochemistry as soon as the 2- and 4-cell stages as a cytoplasmic form and becomes exclusively nuclear thereafter, whereas the H3K27me3 mark is detected starting from the gastrula stage and later. Morpholino invalidation of Ci-E(z) leads to the total disappearance of both Ci-E(z) protein and its H3K27me3 mark. Ci-E(z) morphants display a severe phenotype. Strikingly, the earliest defects occur at the 4-cell stage with the dysregulation of cell positioning and mitotic impairment. At later stages, Ci-E(z)-deficient embryos are affected by terminal differentiation defects of neural, epidermal and muscle tissues, by the failure to form a notochord and by the absence of caudal nerve. These major phenotypic defects are specifically rescued by injection of a morpholino-resistant Ci-E(z) mRNA, which restores expression of Ci-E(z) protein and re-deposition of the H3K27me3 mark. As observed by qPCR analyses, Ci-E(z) invalidation leads to the early derepression of tissue-specific developmental genes, whereas late-acting developmental genes are generally down-regulated. Altogether, our results suggest that Ci-E(z) plays a major role during embryonic development in Ciona intestinalis by silencing early-acting developmental genes in a Hox-independent manner. PMID:26276097

Developmental regulation of neuroligin genes in Japanese rice fish (oryzias latipes) embryogenesis maintains the rhythym during ethanol-in

USDA-ARS?s Scientific Manuscript database

Although prenatal alcohol exposure is the potential cause of fetal alcohol spectrum disorder (FASD) in humans, the molecular mechanism(s) of FASD is yet unknown. We have used Japanese rice fish (Oryzias latipes) embryogenesis as an animal model of FASD and reported that this model has effectively ge...

Influences of DMP on the Fertilization Process and Subsequent Embryogenesis of Abalone (Haliotis diversicolor supertexta) by Gametes Exposure

PubMed Central

Cai, Zhong-Hua

2011-01-01

Di-methyl phthalate (DMP), a typical endocrine disrupting chemical (EDC), is ubiquitously distributed in aquatic environments; yet studies regarding its impact on gametes and the resulting effects on embryogenesis in marine gastropods are relatively scarce. In this study, the influences of DMP on the gametes and subsequent developmental process of abalone (Haliotis diversicolor supertexta, a representative marine benthic gastropod) were assessed. Newborn abalone eggs and sperm were exposed separately to different DMP concentrations (1, 10 or 100 ppb) for 60 min. At the end-point of exposure, the DMP-treated eggs and sperm were collected for analysis of their ultra-structures, ATPase activities and total lipid levels, and the fertilized gametes (embryos) were collected to monitor related reproductive parameters (fertilization rate, abnormal development rate and hatching success rate). Treatment with DMP did not significantly alter the structure or total lipid content of eggs at any of the doses tested. Hatching failures and morphological abnormalities were only observed with the highest dose of DMP (100 ppb). However, DMP exposure did suppress sperm ATPase activities and affect the morphological character of their mitochondria. DMP-treated sperm exhibited dose-dependent decreases in fertilization efficiency, morphogenesis and hatchability. Relatively obvious toxicological effects were observed when both sperm and eggs were exposed to DMP. Furthermore, RT-PCR results indicate that treatment of gametes with DMP changed the expression patterns of physiologically-regulated genes (cyp3a, 17β-HSD-11 and 17β-HSD-12) in subsequent embryogenesis. Taken together, this study proofed that pre-fertilization exposure of abalone eggs, sperm or both to DMP adversely affects the fertilization process and subsequent embryogenesis. PMID:22028799

Metabolome analysis of Drosophila melanogaster during embryogenesis.

PubMed

An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

2014-01-01

The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos' metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo.

Metabolome Analysis of Drosophila melanogaster during Embryogenesis

PubMed Central

An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

2014-01-01

The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos’ metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo. PMID:25121768

Effects of GhWUS from upland cotton (Gossypium hirsutum L.) on somatic embryogenesis and shoot regeneration.

PubMed

Xiao, Yanqing; Chen, Yanli; Ding, Yanpeng; Wu, Jie; Wang, Peng; Yu, Ya; Wei, Xi; Wang, Ye; Zhang, Chaojun; Li, Fuguang; Ge, Xiaoyang

2018-05-01

The WUSCHEL (WUS) gene encodes a plant-specific homeodomain-containing transcriptional regulator, which plays important roles during embryogenesis, as well as in the formation of shoot and flower meristems. Here, we isolated two homologues of Arabidopsis thaliana WUS (AtWUS), GhWUS1a_At and GhWUS1b_At, from upland cotton (Gossypium hirsutum). Domain analysis suggested that the two putative GhWUS proteins contained a highly conserved DNA-binding HOX domain and a WUS-box. Expression profile analysis showed that GhWUSs were predominantly expressed during the embryoid stage. Ectopic expression of GhWUSs in Arabidopsis could induce somatic embryo and shoot formation from seedling root tips. Furthermore, in the absence of exogenous hormone, overexpression of GhWUSs in Arabidopsis could promote shoot regeneration from excised roots, and in the presence of exogenous auxin, excised roots expressing GhWUS could be induced to produce somatic embryo. In addition, expression of the chimeric GhWUS repressor in cotton callus inhibited embryogenic callus formation. Our results show that GhWUS is an important regulator of somatic embryogenesis and shoot regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

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

PubMed

Prabhudesai, V; Bhaskaran, S

1993-03-01

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

MicroRNA-20a is essential for normal embryogenesis by targeting vsx1 mRNA in fish

PubMed Central

Sun, Lei; Li, Heng; Xu, Xiaofeng; Xiao, Guanxiu; Luo, Chen

2015-01-01

MicroRNAs are major post-transcriptional regulators of gene expression and have essential roles in diverse developmental processes. In vertebrates, some regulatory genes play different roles at different developmental stages. These genes are initially transcribed in a wide embryonic region but restricted within distinct cell types at subsequent stages during development. Therefore, post-transcriptional regulation is required for the transition from one developmental stage to the next and the establishment of different cell identities. However, the regulation of many multiple functional genes at post-transcription level during development remains unknown. Here we show that miR-20a can target the mRNA of vsx1, a multiple functional gene, at the 3′-UTR and inhibit protein expression in both goldfish and zebrafish. The expression of miR-20a is initiated ubiquitously at late gastrula stage and exhibits a tissue-specific pattern in the developing retina. Inhibition of vsx1 3′-UTR mediated protein expression occurs when and where miR-20a is expressed. Decoying miR-20a resulted in severely impaired head, eye and trunk formation in association with excessive generation of vsx1 marked neurons in the spinal cord and defects of somites in the mesoderm region. These results demonstrate that miR-20a is essential for normal embryogenesis by restricting Vsx1 expression in goldfish and zebrafish, and that post-transcriptional regulation is an essential mechanism for Vsx1 playing different roles in diverse developmental processes. PMID:25833418

Integrated genomic approaches identify major pathways and upstream regulators in late onset Alzheimer’s disease

PubMed Central

Li, Xinzhong; Long, Jintao; He, Taigang; Belshaw, Robert; Scott, James

2015-01-01

Previous studies have evaluated gene expression in Alzheimer’s disease (AD) brains to identify mechanistic processes, but have been limited by the size of the datasets studied. Here we have implemented a novel meta-analysis approach to identify differentially expressed genes (DEGs) in published datasets comprising 450 late onset AD (LOAD) brains and 212 controls. We found 3124 DEGs, many of which were highly correlated with Braak stage and cerebral atrophy. Pathway Analysis revealed the most perturbed pathways to be (a) nitric oxide and reactive oxygen species in macrophages (NOROS), (b) NFkB and (c) mitochondrial dysfunction. NOROS was also up-regulated, and mitochondrial dysfunction down-regulated, in healthy ageing subjects. Upstream regulator analysis predicted the TLR4 ligands, STAT3 and NFKBIA, for activated pathways and RICTOR for mitochondrial genes. Protein-protein interaction network analysis emphasised the role of NFKB; identified a key interaction of CLU with complement; and linked TYROBP, TREM2 and DOK3 to modulation of LPS signalling through TLR4 and to phosphatidylinositol metabolism. We suggest that NEUROD6, ZCCHC17, PPEF1 and MANBAL are potentially implicated in LOAD, with predicted links to calcium signalling and protein mannosylation. Our study demonstrates a highly injurious combination of TLR4-mediated NFKB signalling, NOROS inflammatory pathway activation, and mitochondrial dysfunction in LOAD. PMID:26202100

In vitro regeneration through organogenesis and somatic embryogenesis in pigeon pea [ Cajanus cajan (L.) Millsp.] cv. JKR105.

PubMed

Krishna, Gaurav; Reddy, P Sairam; Ramteke, Pramod W; Rambabu, Pogiri; Sohrab, Sayed S; Rana, Debashis; Bhattacharya, Parthasarathi

2011-10-01

In vitro regeneration of pigeon pea through organogenesis and somatic embryogenesis was demonstrated with pigeon pea cv. JKR105. Embryonic axes explants of pigeon pea showed greater regeneration of shoot buds on 2.5 mg L(-1) 6-benzylaminopurine (BAP) in the medium, followed by further elongation at lower concentrations. Rooting of shoots was observed on half-strength Murashige and Skoog (MS) medium with 2 % sucrose and 0.5 mg L(-1) 3-indolebutyric acid (IBA). On the other hand, the regeneration of globular embryos from cotyledon explant was faster and greater with thidiazuron (TDZ) than BAP with sucrose as carbohydrate source. These globular embryos were maturated on MS medium with abscisic acid (ABA) and finally germinated on half-strength MS medium at lower concentrations of BAP. Comparison of regeneration pathways in pigeon pea cv. JKR105 showed that the turnover of successful establishment of plants achieved through organogenesis was more compared to somatic embryogenesis, despite the production of more embryos than shoot buds.

Developmental regulation of neuroligin genes in Japanese ricefish (Oryzias latipes) embryogenesis maintains the rhythm during ethanol-induced fetal alcohol spectrum disorder.

PubMed

Haron, Mona H; Khan, Ikhlas A; Dasmahapatra, Asok K

2014-01-01

Although prenatal alcohol exposure is the potential cause of fetal alcohol spectrum disorder (FASD) in humans, the molecular mechanism(s) of FASD is yet unknown. We have used Japanese ricefish (Oryzias latipes) embryogenesis as an animal model of FASD and reported that this model has effectively generated several phenotypic features in the cardiovasculature and neurocranial cartilages by developmental ethanol exposure which is analogous to human FASD phenotypes. As FASD is a neurobehavioral disorder, we are searching for a molecular target of ethanol that alters neurological functions. In this communication, we have focused on neuroligin genes (nlgn) which are known to be active at the postsynaptic side of both excitatory and inhibitory synapses of the central nervous system. There are six human NLGN homologs of Japanese ricefish reported in public data bases. We have partially cloned these genes and analyzed their expression pattern during normal development and also after exposing the embryos to ethanol. Our data indicate that the expression of all six nlgn genes in Japanese ricefish embryos is developmentally regulated. Although ethanol is able to induce developmental abnormalities in Japanese ricefish embryogenesis comparable to the FASD phenotypes, quantitative real-time PCR (qPCR) analysis of nlgn mRNAs indicate unresponsiveness of these genes to ethanol. We conclude that the disruption of the developmental rhythm of Japanese ricefish embryogenesis by ethanol that leads to FASD may not affect the nlgn gene expression at the message level. © 2013.

The vertebrate phylotypic stage and an early bilaterian-related stage in mouse embryogenesis defined by genomic information.

PubMed

Irie, Naoki; Sehara-Fujisawa, Atsuko

2007-01-12

Embryos of taxonomically different vertebrates are thought to pass through a stage in which they resemble one another morphologically. This "vertebrate phylotypic stage" may represent the basic vertebrate body plan that was established in the common ancestor of vertebrates. However, much controversy remains about when the phylotypic stage appears, and whether it even exists. To overcome the limitations of studies based on morphological comparison, we explored a comprehensive quantitative method for defining the constrained stage using expressed sequence tag (EST) data, gene ontologies (GO), and available genomes of various animals. If strong developmental constraints occur during the phylotypic stage of vertebrate embryos, then genes conserved among vertebrates would be highly expressed at this stage. We established a novel method for evaluating the ancestral nature of mouse embryonic stages that does not depend on comparative morphology. The numerical "ancestor index" revealed that the mouse indeed has a highly conserved embryonic period at embryonic day 8.0-8.5, the time of appearance of the pharyngeal arch and somites. During this period, the mouse prominently expresses GO-determined developmental genes shared among vertebrates. Similar analyses revealed the existence of a bilaterian-related period, during which GO-determined developmental genes shared among bilaterians are markedly expressed at the cleavage-to-gastrulation period. The genes associated with the phylotypic stage identified by our method are essential in embryogenesis. Our results demonstrate that the mid-embryonic stage of the mouse is indeed highly constrained, supporting the existence of the phylotypic stage. Furthermore, this candidate stage is preceded by a putative bilaterian ancestor-related period. These results not only support the developmental hourglass model, but also highlight the hierarchical aspect of embryogenesis proposed by von Baer. Identification of conserved stages and tissues

The final step of the ethylene biosynthesis pathway in turnip tops (Brassica rapa): molecular characterization of the 1-aminocyclopropane-1-carboxylate oxidase BrACO1 throughout zygotic embryogenesis and germination of heterogeneous seeds.

PubMed

Del Carmen Rodríguez-Gacio, María; Nicolás, Carlos; Matilla, Angel Jesús

2004-05-01

In a previous report from the present authors, it was shown that the 1-aminocyclopropane-1-carboxylate (ACC) oxidation may play a crucial role during zygotic embryogenesis of turnip tops seeds. The present study was performed to elucidate the contribution of the silique-wall and seeds in ethylene production during this developmental process. ACC content in the silique wall is only higher than in seeds during the middle phases of zygotic embryogenesis. The ACC-oxidase (ACO) activity peaks in the silique-wall and seeds during the onset of embryogenesis, declining gradually afterwards, being undetectable during desiccation period. Using reverse transcriptase-polymerase chain reaction, one cDNA clone coding for an ACO and called BrACO1, was isolated. The deduced protein for BrACO1 has a molecular weight of 36.8 kDa and a high homology with other crucifer ACOs. The heterologous expression of this cDNA confirmed that BrACO1 is an ACO. The expression of this gene was high during the first phases of silique-wall development, low during the middle phases and undetectable during desiccation. By contrast, BrACO1 transcript was accumulated only in the earliest phases of seed embryogenesis and may participate in the highest ACO activity and ethylene production by seeds at the beginning of embryogenesis. Finally, in this work a correlation between the heterogeneity of Brassica rapa L. cv. Rapa seeds and the ability to oxidize the ACC to ethylene has been demonstrated.

High stability of nuclear microsatellite loci during the early stages of somatic embryogenesis in Norway spruce.

PubMed

Helmersson, Andreas; von Arnold, Sara; Burg, Kornel; Bozhkov, Peter V

2004-10-01

Somatic embryos of Norway spruce (Picea abies (L.) Karst.) differentiate from proembryogenic masses (PEMs), which are subject to autodestruction through programmed cell death. In PEMs, somatic embryo formation and activation of programmed cell death are interrelated processes. We sought to determine if activation of programmed cell death in PEMs is caused by genetic aberrations during somatic embryogenesis. Based on the finding that withdrawal of auxin and cytokinin induces programmed cell death in PEMs, 1-week-old cell suspensions were cultured in medium either with or without auxin and cytokinin and then transferred to maturation medium containing abscisic acid. We analyzed the stability of three nuclear simple sequence repeat (SSR) microsatellite markers at successive stages of somatic embryogenesis in two cell lines. There were no mutations at the SSR loci at any of the successive developmental stages from PEMs to cotyledonary embryos, irrespective of whether or not the proliferation medium in which cell suspensions had been cultured contained auxin or cytokinin. The morphologies of plants regenerated from the cultures were similar, although withdrawal of auxin and cytokinin significantly stimulated the yield of both embryos and plants. We conclude, therefore, that the high genetic stability of somatic embryos in Norway spruce is unaffected by the induction of programmed cell death caused by withdrawal of auxin and cytokinin.

G-protein-coupled estrogen receptor 1 is involved in brain development during zebrafish (Danio rerio) embryogenesis

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

Shi, Yanan; Liu, Xiaochun; Zhu, Pei

Highlights: •The Gper expression was detected in the developing brain of zebrafish. •Gper morpholino knockdown induced apoptosis of brain cells. •Gper morpholino knockdown reduced expression in neuron markers. •Zebrafish Gper may be involved in neuronal development. -- Abstract: G-protein-coupled estrogen receptor 1 (Gper, formerly known as GPR30) is found to be a trophic and protective factor in mediating action of estrogen in adult brain, while its role in developing brain remains to be elucidated. Here we present the expression pattern of Gper and its functions during embryogenesis in zebrafish. Both the mRNA and protein of Gper were detected throughout embryogenesis.more » Whole mount in situ hybridization (WISH) revealed a wide distribution of gper mRNAs in various regions of the developing brain. Gper knockdown by specific morpholinos resulted in growth retardation in embryos and morphological defects in the developing brain. In addition, induced apoptosis, decreased proliferation of the brain cells and maldevelopment of sensory and motor neurons were also found in the morphants. Our results provide novel insights into Gper functions in the developing brain, revealing that Gper can maintain the survival of the brain cells, and formation and/or differentiation of the sensory and motor neurons.« less

Effect of microgravity and hypergravity on embryo axis alignment during postencystment embryogenesis in Artemia franciscana (Anostraca)

NASA Technical Reports Server (NTRS)

Rosowski, J. R.; Gouthro, M. A.; Schmidt, K. K.; Klement, B. J.; Spooner, B. S.

1995-01-01

Cysts of brine shrimp attached with a liquid adhesive to 12-mm diameter glass coverslips in a syringe-type fluid processing apparatus were flown aboard the NASA space shuttle Discovery, flight STS-60, from 3-11 February 1994, and were allowed to undergo postencystment embryogenesis and to hatch in microgravity. The shuttle flight and the ground-based control coverslips with attached cysts were parallel to the earth's surface during incubation in salt water. Based on the position of the cyst shell crack in the attached cyst population, the ground-control nauplii emerged mostly upward. On the shuttle in microgravity, although our method of detection of orientation would not reveal emergence toward the coverslip, the ratio of the position of the cyst shell crack in the population after hatching best fit the predicted values of a random direction for nauplii emergence. Centrifugation on earth was then used to create hypergravity forces of up to 73 g during postencystment embryogenesis and hatching. The upward orientation of emerging nauplii showed a high degree of correlation (r(2) =98.8%) with a linear relationship to the log of g, with 78.2% of the total hatching upward at 1 g and 91.0% hatching upward at 73 g.

Doubled haploid production from Spanish onion (Allium cepa L.) germplasm: embryogenesis induction, plant regeneration and chromosome doubling.

PubMed

Fayos, Oreto; Vallés, María P; Garcés-Claver, Ana; Mallor, Cristina; Castillo, Ana M

2015-01-01

The use of doubled haploids in onion breeding is limited due to the low gynogenesis efficiency of this species. Gynogenesis capacity from Spanish germplasm, including the sweet cultivar Fuentes de Ebro, the highly pungent landrace BGHZ1354 and the two Valenciana type commercial varieties Recas and Rita, was evaluated and optimized in this study. The OH-1 population, characterized by a high gynogenesis induction, was used as control. Growing conditions of the donor plants were tested with a one-step protocol and field plants produced a slightly higher percentage of embryogenesis induction than growth chamber plants. A one-step protocol was compared with a two-step protocol for embryogenesis induction. Spanish germplasm produced a 2-3 times higher percentage of embryogenesis with the two-step protocol, Recas showing the highest percentage (2.09%) and Fuentes de Ebro the lowest (0.53%). These percentages were significantly lower than those from the OH-1 population, with an average of 15% independently of the protocol used. The effect of different containers on plant regeneration was tested using both protocols. The highest percentage of acclimated plants was obtained with the two-step protocol in combination with Eco2box (70%), whereas the lowest percentage was observed with glass tubes in the two protocols (20-23%). Different amiprofos-methyl (APM) treatments were applied to embryos for chromosome doubling. A similar number of doubled haploid plants were recovered with 25 or 50 μM APM in liquid medium. However, the application of 25 μM in solid medium for 24 h produced the highest number of doubled haploid plants. Somatic regeneration from flower buds of haploid and mixoploid plants proved to be a successful approach for chromosome doubling, since diploid plants were obtained from the four regenerated lines. In this study, doubled haploid plants were produced from the four Spanish cultivars, however further improvements are needed to increase their gynogenesis

DNA methyltransferase expressions in Japanese rice fish (Oryzias latipes) embryogenesis is developmentally regulated and modulated by ethanol and 5-azacytidine

USDA-ARS?s Scientific Manuscript database

We aimed to investigate the impact of the epigenome in inducting fetal alcohol spectrum disorder (FASD) phenotypes in Japanese rice fish embryogenesis. One of the significant events in epigenome is DNA methylation which is catalyzed by DNA methyl transferase (DNMT) enzymes. We analyzed DNMT enzyme m...

Novel Mitochondria-Targeted Heat-Soluble Proteins Identified in the Anhydrobiotic Tardigrade Improve Osmotic Tolerance of Human Cells

PubMed Central

Tanaka, Sae; Tanaka, Junko; Miwa, Yoshihiro; Horikawa, Daiki D.; Katayama, Toshiaki; Arakawa, Kazuharu; Toyoda, Atsushi; Kubo, Takeo; Kunieda, Takekazu

2015-01-01

Tardigrades are able to tolerate almost complete dehydration through transition to a metabolically inactive state, called “anhydrobiosis”. Late Embryogenesis Abundant (LEA) proteins are heat-soluble proteins involved in the desiccation tolerance of many anhydrobiotic organisms. Tardigrades, Ramazzottius varieornatus, however, express predominantly tardigrade-unique heat-soluble proteins: CAHS (Cytoplasmic Abundant Heat Soluble) and SAHS (Secretory Abundant Heat Soluble) proteins, which are secreted or localized in most intracellular compartments, except the mitochondria. Although mitochondrial integrity is crucial to ensure cellular survival, protective molecules for mitochondria have remained elusive. Here, we identified two novel mitochondrial heat-soluble proteins, RvLEAM and MAHS (Mitochondrial Abundant Heat Soluble), as potent mitochondrial protectants from Ramazzottius varieornatus. RvLEAM is a group3 LEA protein and immunohistochemistry confirmed its mitochondrial localization in tardigrade cells. MAHS-green fluorescent protein fusion protein localized in human mitochondria and was heat-soluble in vitro, though no sequence similarity with other known proteins was found, and one region was conserved among tardigrades. Furthermore, we demonstrated that RvLEAM protein as well as MAHS protein improved the hyperosmotic tolerance of human cells. The findings of the present study revealed that tardigrade mitochondria contain at least two types of heat-soluble proteins that might have protective roles in water-deficient environments. PMID:25675104

Novel mitochondria-targeted heat-soluble proteins identified in the anhydrobiotic Tardigrade improve osmotic tolerance of human cells.

PubMed

Tanaka, Sae; Tanaka, Junko; Miwa, Yoshihiro; Horikawa, Daiki D; Katayama, Toshiaki; Arakawa, Kazuharu; Toyoda, Atsushi; Kubo, Takeo; Kunieda, Takekazu

2015-01-01

Tardigrades are able to tolerate almost complete dehydration through transition to a metabolically inactive state, called "anhydrobiosis". Late Embryogenesis Abundant (LEA) proteins are heat-soluble proteins involved in the desiccation tolerance of many anhydrobiotic organisms. Tardigrades, Ramazzottius varieornatus, however, express predominantly tardigrade-unique heat-soluble proteins: CAHS (Cytoplasmic Abundant Heat Soluble) and SAHS (Secretory Abundant Heat Soluble) proteins, which are secreted or localized in most intracellular compartments, except the mitochondria. Although mitochondrial integrity is crucial to ensure cellular survival, protective molecules for mitochondria have remained elusive. Here, we identified two novel mitochondrial heat-soluble proteins, RvLEAM and MAHS (Mitochondrial Abundant Heat Soluble), as potent mitochondrial protectants from Ramazzottius varieornatus. RvLEAM is a group3 LEA protein and immunohistochemistry confirmed its mitochondrial localization in tardigrade cells. MAHS-green fluorescent protein fusion protein localized in human mitochondria and was heat-soluble in vitro, though no sequence similarity with other known proteins was found, and one region was conserved among tardigrades. Furthermore, we demonstrated that RvLEAM protein as well as MAHS protein improved the hyperosmotic tolerance of human cells. The findings of the present study revealed that tardigrade mitochondria contain at least two types of heat-soluble proteins that might have protective roles in water-deficient environments.

A proteomic study to identify soya allergens--the human response to transgenic versus non-transgenic soya samples.

PubMed

Batista, Rita; Martins, Isabel; Jeno, Paul; Ricardo, Cândido Pinto; Oliveira, Maria Margarida

2007-01-01

In spite of being among the main foods responsible for allergic reactions worldwide, soybean (Glycine max)-derived products continue to be increasingly widespread in a variety of food products due to their well-documented health benefits. Soybean also continues to be one of the elected target crops for genetic modification. The aim of this study was to characterize the soya proteome and, specifically, IgE-reactive proteins as well as to compare the IgE response in soya-allergic individuals to genetically modified Roundup Ready soya versus its non-transgenic control. We performed two-dimensional gel electrophoresis of protein extracts from a 5% genetically modified Roundup Ready flour sample and its non-transgenic control followed by Western blotting with plasma from 5 soya-sensitive individuals. We used peptide tandem mass spectrometry to identify soya proteins (55 protein matches), specifically IgE-binding ones, and to evaluate differences between transgenic and non-transgenic samples. We identified 2 new potential soybean allergens--one is maturation associated and seems to be part of the late embryogenesis abundant proteins group and the other is a cysteine proteinase inhibitor. None of the individuals tested reacted differentially to the transgenic versus non-transgenic samples under study. Soybean endogenous allergen expression does not seem to be altered after genetic modification. Proteomics should be considered a powerful tool for functional characterization of plants and for food safety assessment. Copyright (c) 2007 S. Karger AG, Basel.

Characterization of somatic embryogenesis initiated from the Arabidopsis shoot apex.

PubMed

Kadokura, Satoshi; Sugimoto, Kaoru; Tarr, Paul; Suzuki, Takamasa; Matsunaga, Sachihiro

2018-04-28

Somatic embryogenesis is one of the best examples of the remarkable developmental plasticity of plants, in which committed somatic cells can dedifferentiate and acquire the ability to form an embryo and regenerate an entire plant. In Arabidopsis thaliana, the shoot apices of young seedlings have been reported as an alternative tissue source for somatic embryos (SEs) besides the widely studied zygotic embryos taken from siliques. Although SE induction from shoots demonstrates the plasticity of plants more clearly than the embryo-to-embryo induction system, the underlying developmental and molecular mechanisms involved are unknown. Here we characterized SE formation from shoot apex explants by establishing a system for time-lapse observation of explants during SE induction. We also established a method to distinguish SE-forming and non-SE-forming explants prior to anatomical SE formation, enabling us to identify distinct transcriptome profiles of these two explants at SE initiation. We show that embryonic fate commitment takes place at day 3 of SE induction and the SE arises directly, not through callus formation, from the base of leaf primordia just beside the shoot apical meristem (SAM), where auxin accumulates and shoot-root polarity is formed. The expression domain of a couple of key developmental genes for the SAM transiently expands at this stage. Our data demonstrate that SE-forming and non-SE-forming explants share mostly the same transcripts except for a limited number of embryonic genes and root genes that might trigger the SE-initiation program. Thus, SE-forming explants possess a mixed identity (SAM, root and embryo) at the time of SE specification. Copyright © 2018. Published by Elsevier Inc.

Evaluation of haemoglobin (erythrogen): for improved somatic embryogenesis and plant regeneration in cotton (Gossypium hirsutum L. cv. SVPR 2).

PubMed

Ganesan, M; Jayabalan, N

2004-10-01

Somatic embryogenesis in cotton (Gossypium hirsutum L.) is accelerated when the plant regeneration medium is supplemented with haemoglobin (erythrogen). In cotton SVPR 2 lines, a higher frequency of embryoid formation was observed when the medium contained 400 mg/l haemoglobin. Fresh weight of the callus, rate of embryoid induction, number of embryoids formed and the percentage of plant regeneration from somatic embryos were increased. Among the two different cultivars tested, MCU 11 showed no response to the presence of haemoglobin when compared to SVPR 2, and embryogenic callus formation was completely absent in the former. Medium containing MS salts, 100 mg/l myo-inositol , 0.3 mg/l thiamine-HCL, 0.3 mg/l Picloram (PIC), 0.1 mg/l kinetin and 400 mg/l haemoglobin effected a better response with respect to embryogenic callus induction. After 8 weeks of culture, a high frequency of embryoid induction was observed on medium containing MS basal salts, 100 mg/l myo-inositol, 0.3 mg/l PIC , 0.1 mg/l isopentenyl adenine, 1.0 g/l NH4NO3 and 400 mg/l haemoglobin. Plant regeneration was observed in 75.8% of the mature somatic embryos, and whole plant regeneration was achieved within 6-7 months of culture. The regenerated plantlets were fertile and similar to in vivo-grown, seed-derived plants except that they were phenotypically smaller. A positive influence of haemoglobin was observed at concentrations up to 400 mg/l at all stages of somatic embryogenesis. The increase in the levels of antioxidant enzyme activities, for example superoxide dismutase and peroxidase, indicated the presence of excess oxygen uptake and the stressed condition of the plant tissues that arose from haemoglobin supplementation. This increased oxygen uptake and haemoglobin-mediated stress appeared to accelerate somatic embryogenesis in cotton.

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

PubMed Central

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

2011-01-01

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

Modeling cell-cycle synchronization during embryogenesis in Xenopus laevis

NASA Astrophysics Data System (ADS)

McIsaac, R. Scott; Huang, K. C.; Sengupta, Anirvan; Wingreen, Ned

2010-03-01

A widely conserved aspect of embryogenesis is the ability to synchronize nuclear divisions post-fertilization. How is synchronization achieved? Given a typical protein diffusion constant of 10 μm^2sec, and an embryo length of 1mm, it would take diffusion many hours to propagate a signal across the embryo. Therefore, synchrony cannot be attained by diffusion alone. We hypothesize that known autocatalytic reactions of cell-cycle components make the embryo an ``active medium'' in which waves propagate much faster than diffusion, enforcing synchrony. We report on robust spatial synchronization of components of the core cell cycle circuit based on a mathematical model previously determined by in vitro experiments. In vivo, synchronized divisions are preceded by a rapid calcium wave that sweeps across the embryo. Experimental evidence supports the hypothesis that increases in transient calcium levels lead to derepression of a negative feedback loop, allowing cell divisions to start. Preliminary results indicate a novel relationship between the speed of the initial calcium wave and the ability to achieve synchronous cell divisions.

Four queries concerning the metaphysics of early human embryogenesis.

PubMed

Howsepian, A A

2008-04-01

In this essay, I attempt to provide answers to the following four queries concerning the metaphysics of early human embryogenesis. (1) Following its first cellular fission, is it coherent to claim that one and only one of two "blastomeric" twins of a human zygote is identical with that zygote? (2) Following the fusion of two human pre-embryos, is it coherent to claim that one and only one pre-fusion pre-embryo is identical with that postfusion pre-embryo? (3) Does a live human being come into existence only when its brain comes into existence? (4) At implantation, does a pre-embryo become a mere part of its mother? I argue that either if things have quidditative properties or if criterialism is false, then queries (1) and (2) can be answered in the affirmative; that in light of recent developments in theories of human death and in light of a more "functional" theory of brains, query (3) can be answered in the negative; and that plausible mereological principles require a negative answer to query (4).

Preliminary molecular detection of the somatic embryogenesis receptor-like kinase (VpSERK) and knotted-like homeobox (VpKNOX1) genes during in vitro morphogenesis of Vanilla planifolia Jacks.

PubMed

Ramírez-Mosqueda, Marco A; Iglesias-Andreu, Lourdes G; Sáenz, Luis; Córdova, Iván

2018-02-01

This work aimed to evaluate the embryogenic competence of different tissues from different stages (friable callus, bud-regenerating callus, and whole buds) of Vanilla planifolia , through the molecular detection of the somatic embryogenesis receptor-like kinase ( VpSERK ) and knotted-like homeobox ( VpKNOX1 ) genes. RNA was extracted with Trizol ® , cDNA was obtained, and the studied transcripts were amplified. Using non-specific primers, VpSERK and VpSTM gene expression was detected in the three stages evaluated. This study might contribute to providing an explanation for the recalcitrance of this Vanilla species to somatic embryogenesis.

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

PubMed

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

2013-08-30

It is during embryogenesis that the plant body plan is established and the meristems responsible for all post-embryonic growth are specified. The molecular mechanisms governing conifer embryogenesis are still largely unknown. Their elucidation may contribute valuable information to clarify if the distinct features of embryo development in angiosperms and gymnosperms result from differential gene regulation. To address this issue, we have performed the first transcriptomic analysis of zygotic embryo development in a conifer species (Pinus pinaster) focusing our study in particular on regulatory genes playing important roles during plant embryo development, namely epigenetic regulators and transcription factors. Microarray analysis of P. pinaster zygotic embryogenesis was performed at five periods of embryo development from early developing to mature embryos. Our results show that most changes in transcript levels occurred in the first and the last embryo stage-to-stage transitions, namely early to pre-cotyledonary embryo and cotyledonary to mature embryo. An analysis of functional categories for genes that were differentially expressed through embryogenesis highlighted several epigenetic regulation mechanisms. While putative orthologs of transcripts associated with mechanisms that target transposable elements and repetitive sequences were strongly expressed in early embryogenesis, PRC2-mediated repression of genes seemed more relevant during late embryogenesis. On the other hand, functions related to sRNA pathways appeared differentially regulated across all stages of embryo development with a prevalence of miRNA functions in mid to late embryogenesis. Identification of putative transcription factor genes differentially regulated between consecutive embryo stages was strongly suggestive of the relevance of auxin responses and regulation of auxin carriers during early embryogenesis. Such responses could be involved in establishing embryo patterning. Later in

Adhesion mechanisms in embryogenesis and in cancer invasion and metastasis.

PubMed

Thiery, J P; Boyer, B; Tucker, G; Gavrilovic, J; Valles, A M

1988-01-01

Cell-substratum and cell-cell adhesion mechanisms contribute to the development of animal form. The adhesive status of embryonic cells has been analysed during epithelial-mesenchymal cell interconversion and in cell migrations. Clear-cut examples of the modulation of cell adhesion molecules (CAMs) have been described at critical periods of morphogenesis. In chick embryos the three primary CAMs (N-CAM. L-CAM and N-cadherin) present early in embryogenesis are expressed later in a defined pattern during morphogenesis and histogenesis. The axial mesoderm derived from gastrulating cells expresses increasing amounts of N-cadherin and N-CAM. During metamerization these two adhesion molecules become abundant at somitic cell surfaces. Both CAMs are functional in an in vitro aggregation assay; however, the calcium-dependent adhesion molecule N-cadherin is more sensitive to perturbation by specific antibodies. Neural crest cells which separate from the neural epithelium lose their primary CAMs in a defined time-sequence. Adhesion to fibronectins via specific surface receptors becomes a predominant interaction during the migratory process, while some primary and secondary CAMs are expressed de novo during the ontogeny of the peripheral nervous system. In vitro, different fibronectin functional domains have been identified in the attachment, spreading and migration of neural crest cells. The fibronectin receptors which transduce the adhesive signals play a key role in the control of cell movement. All these results have prompted us to examine whether similar mechanisms operate in carcinoma cell invasion and metastasis. In vitro, rat bladder transitional carcinoma cells convert reversibly into invasive mesenchymal cells. A rapid modulation of adhesive properties is found during the epithelial-mesenchymal carcinoma cell interconversion. The different model systems analysed demonstrate that a limited repertoire of adhesion molecules, expressed in a well-defined spatiotemporal

Ixodes pacificus Ticks Maintain Embryogenesis and Egg Hatching after Antibiotic Treatment of Rickettsia Endosymbiont

PubMed Central

Kurlovs, Andre H.; Li, Jinze; Cheng, Du; Zhong, Jianmin

2014-01-01

Rickettsia is a genus of intracellular bacteria that causes a variety of diseases in humans and other mammals and associates with a diverse group of arthropods. Although Rickettsia appears to be common in ticks, most Rickettsia-tick relationships remain generally uncharacterized. The most intimate of these associations is Rickettsia species phylotype G021, a maternally and transstadially transmitted endosymbiont that resides in 100% of I. pacificus in California. We investigated the effects of this Rickettsia phylotype on I. pacificus reproductive fitness using selective antibiotic treatment. Ciprofloxacin was 10-fold more effective than tetracycline in eliminating Rickettsia from I. pacificus, and quantitative PCR results showed that eggs from the ciprofloxacin-treated ticks contained an average of 0.02 Rickettsia per egg cell as opposed to the average of 0.2 in the tetracycline-treated ticks. Ampicillin did not significantly affect the number of Rickettsia per tick cell in adults or eggs compared to the water-injected control ticks. We found no relationship between tick embryogenesis and rickettsial density in engorged I. pacificus females. Tetracycline treatment significantly delayed oviposition of I. pacificus ticks, but the antibiotic’s effect was unlikely related to Rickettsia. We also demonstrated that Rickettsia-free eggs could successfully develop into larvae without any significant decrease in hatching compared to eggs containing Rickettsia. No significant differences in the incubation period, egg hatching rate, and the number of larvae were found between any of the antibiotic-treated groups and the water-injected tick control. We concluded that Rickettsia species phylotype G021 does not have an apparent effect on embryogenesis, oviposition, and egg hatching of I. pacificus. PMID:25105893

Cell dedifferentiation, callus induction and somatic embryogenesis in Crataegus spp.

PubMed

Taimori, N; Kahrizi, D; Abdossi, V; Papzan, A H

2016-09-30

The present study describes the effects of light conditions, different kinds and concentrations of auxins [Naphthylacetic acid (NAA) and dichlorophenoxyacetic acid (2,4-D)] with cytokinin (Kin) in MS medium on callus induction and embryogenesis in Crataegus pseudoheterophylla, C. aronia and C.meyeri. At first leave explants sections were cultured on different combinations of plant growth regulators in dark and light for callus initiation and light conditions to evaluation the percentage and duration of survival, callus diameter, callus fresh weight and dry. Results of effects of plant growth regulators and light conditions on callus initiation revealed that highest percentage of callus initiation leaves in treatment (0.5 mg/l 2.4-D+0.5 mg/l KIN) for species C.pseudoheterophylla in dark conditions (100%). Dark conditions (100%) were more effective on callogenesis than light conditions (Photoperiodicity of 16-h and at light intensity of 40 µmol m-2 s-1). The callus induction of in vitro (64-100%) leaves was better than the ex vitro ones (0-100%). The combination of 2,4-D and Kin of in vitro leaves callogenesis has been indicated faster (one weeks) than the other combinations. The results also showed that the highest percentage (100%) and survival duration (6 months) was found in species C. pseudoheterophylla and C. meyeri in 0.1 mg/l 2,4.D + 0.5 mg/l KIN and 0.5 mg/l 2,4.D + 0.5 mg/l Kin. The minimum survival (0%) was absorbed in species C. aronia in 1 mg/l NAA. Maximum callus (10.63 and 10.00 mm respectively) was shown in 0.1 mg/l 2,4.D + 0.5 mg/l Kin and 0.5 mg/l 2,4.D + 0.5 mg/l Kin and was not significant differences after five week among species. The results showed that the highest fresh (1081.49 mg) and dry weight (506.88 and 506.98 mg respectively) was absorbed in species C. pseudoheterophylla in 0.1 mg/l 2,4.D + 0.5 mg/l Kin and 0.5 mg/l 2,4.D + 0.5 mg/l Kin. The embryogenesis was not occurred in any plant growth regulator combinations and species. The

Spatio-temporal accumulation and activity of calcium-dependent protein kinases during embryogenesis, seed development, and germination in sandalwood.

PubMed

Anil, V S; Harmon, A C; Rao, K S

2000-04-01

Western-blot analysis and protein kinase assays identified two Ca(2+)-dependent protein kinases (CDPKs) of 55 to 60 kD in soluble protein extracts of embryogenic cultures of sandalwood (Santalum album L.). However, these sandalwood CDPKs (swCDPKs) were absent in plantlets regenerated from somatic embryos. swCDPKs exhibited differential expression (monitored at the level of the protein) and activity in different developmental stages. Zygotic embryos, seedlings, and endosperm showed high accumulation of swCDPK, but the enzyme was not detected in the soluble proteins of shoots and flowers. swCDPK exhibited a temporal pattern of expression in endosperm, showing high accumulation and activity in mature fruit and germinating stages; the enzyme was localized strongly in the storage bodies of the endosperm cells. The study also reports for the first time to our knowledge a post-translational inhibition/inactivation of swCDPK in zygotic embryos during seed dormancy and early stages of germination. The temporal expression of swCDPK during somatic/zygotic embryogenesis, seed maturation, and germination suggests involvement of the enzyme in these developmental processes.

The low molecular weight fraction of compounds released from immature wheat pistils supports barley pollen embryogenesis.

PubMed

Lippmann, Rico; Friedel, Swetlana; Mock, Hans-Peter; Kumlehn, Jochen

2015-01-01

Pollen embryogenesis provides a useful means of generating haploid plants for plant breeding and basic research. Although it is well-established that the efficacy of the process can be enhanced by the provision of immature pistils as a nurse tissue, the origin and compound class of the signal molecule(s) involved is still elusive. Here, a micro-culture system was established to enable the culturing of populations of barley pollen at a density too low to allow unaided embryogenesis to occur, and this was then exploited to assess the effect of using various parts of the pistil as nurse tissue. A five-fold increase in the number of embryogenic calli formed was obtained by simply cutting the pistils in half. The effectiveness of the pistil-conditioned medium was transitory, since it needed replacement at least every 4 days to measurably ensure embryogenic development. The differential effect of various size classes of compounds present in the pistil-conditioned medium showed that the relevant molecule(s) was of molecular weight below 3 kDa. This work narrows down possible feeder molecules to lower molecular weight compounds and showed that the cellular origin of the active compound(s) is not specific to any tested part of the pistil. Furthermore, the increased recovery of calli during treatment with cut pistils may provide a useful tool for plant breeders and researchers using haploid technology in barley and other plant species.

Bottlenecks in bog pine multiplication by somatic embryogenesis and their visualization with the environmental scanning electron microscope.

PubMed

Vlašínová, Helena; Neděla, Vilem; Đorđević, Biljana; Havel, Ladislav

2017-07-01

Somatic embryogenesis (SE) is an important biotechnological technique used for the propagation of many pine species in vitro. However, in bog pine, one of the most endangered tree species in the Czech Republic, limitations were observed, which negatively influenced the development and further germination of somatic embryos. Although initiation frequency was very low-0.95 %, all obtained cell lines were subjected to maturation. The best responding cell line (BC1) was used and subjected to six different variants of the maturation media. The media on which the highest number of early-precotyledonary/cotyledonary somatic embryos was formed was supplemented with 121 μM abscisic acid (ABA) and with 6 % maltose. In the end of maturation experiments, different abnormalities in formation of somatic embryos were observed. For visualization and identification of abnormalities in meristem development during proliferation and maturation processes, the environmental scanning electron microscope was used. In comparison to the classical light microscope, the non-commercial environmental scanning electron microscope AQUASEM II has been found as a very useful tool for the quick recognition of apical meristem disruption and abnormal development. To our knowledge, this is the first report discussing somatic embryogenesis in bog pine. Based on this observation, the cultivation procedure could be enhanced and the method for SE of bog pine optimized.

CLOCK expression identifies developing circadian oscillator neurons in the brains of Drosophila embryos.

PubMed

Houl, Jerry H; Ng, Fanny; Taylor, Pete; Hardin, Paul E

2008-12-18

The Drosophila circadian oscillator is composed of transcriptional feedback loops in which CLOCK-CYCLE (CLK-CYC) heterodimers activate their feedback regulators period (per) and timeless (tim) via E-box mediated transcription. These feedback loop oscillators are present in distinct clusters of dorsal and lateral neurons in the adult brain, but how this pattern of expression is established during development is not known. Since CLK is required to initiate feedback loop function, defining the pattern of CLK expression in embryos and larvae will shed light on oscillator neuron development. A novel CLK antiserum is used to show that CLK expression in the larval CNS and adult brain is limited to circadian oscillator cells. CLK is initially expressed in presumptive small ventral lateral neurons (s-LNvs), dorsal neurons 2 s (DN2s), and dorsal neuron 1 s (DN1s) at embryonic stage (ES) 16, and this CLK expression pattern persists through larval development. PER then accumulates in all CLK-expressing cells except presumptive DN2s during late ES 16 and ES 17, consistent with the delayed accumulation of PER in adult oscillator neurons and antiphase cycling of PER in larval DN2s. PER is also expressed in non-CLK-expressing cells in the embryonic CNS starting at ES 12. Although PER expression in CLK-negative cells continues in ClkJrk embryos, PER expression in cells that co-express PER and CLK is eliminated. These data demonstrate that brain oscillator neurons begin development during embryogenesis, that PER expression in non-oscillator cells is CLK-independent, and that oscillator phase is an intrinsic characteristic of brain oscillator neurons. These results define the temporal and spatial coordinates of factors that initiate Clk expression, imply that circadian photoreceptors are not activated until the end of embryogenesis, and suggest that PER functions in a different capacity before oscillator cell development is initiated.

Chick embryogenesis: a unique platform to study the effects of environmental factors on embryo development.

PubMed

Yahav, S; Brake, J

2014-01-01

Bird embryogenesis takes place in a relatively protected environment that can be manipulated especially well in domestic fowl (chickens) where incubation has long been a commercial process. The embryonic developmental process has been shown to begin in the oviduct such that the embryo has attained either the blastodermal and/or gastrulation stage of development at oviposition. Bird embryos can be affected by "maternal effects," and by environmental conditions during the pre-incubation and incubation periods. "Maternal effects" has been described as an evolutionary mechanism that has provided the mother, by hormonal deposition into the yolk, with the potential to proactively influence the development of her progeny by exposing them to her particular hormonal pattern in such a manner as to influence their ability to cope with the expected wide range of environmental conditions that may occur post-hatching. Another important aspect of "maternal effects" is the effect of the maternal nutrient intake on progeny traits. From a commercial broiler chicken production perspective, it has been established that greater cumulative nutrient intake by the hen during her pullet rearing phase prior to photostimulation resulted in faster growing broiler progeny. Generally, maternal effects on progeny, which have both a genetic and an environmental component represented by yolk hormones deposition and embryo nutrient utilization, have an important effect on the development of a wide range of progeny traits. Furthermore, commercial embryo development during pre-incubation storage and incubation, as well as during incubation per se has been shown to largely depend upon temperature, while other environmental factors that include egg position during storage, and the amount of H2O and CO2 lost by the egg and the subsequent effect on albumen pH and height during storage have become important environmental factors to be considered for successful embryogenesis under commercial conditions

Non-equivalent contributions of maternal and paternal genomes to early plant embryogenesis.

PubMed

Del Toro-De León, Gerardo; García-Aguilar, Marcelina; Gillmor, C Stewart

2014-10-30

Zygotic genome activation in metazoans typically occurs several hours to a day after fertilization, and thus maternal RNAs and proteins drive early animal embryo development. In plants, despite several molecular studies of post-fertilization transcriptional activation, the timing of zygotic genome activation remains a matter of debate. For example, two recent reports that used different hybrid ecotype combinations for RNA sequence profiling of early Arabidopsis embryo transcriptomes came to divergent conclusions. One identified paternal contributions that varied by gene, but with overall maternal dominance, while the other found that the maternal and paternal genomes are transcriptionally equivalent. Here we assess paternal gene activation functionally in an isogenic background, by performing a large-scale genetic analysis of 49 EMBRYO DEFECTIVE genes and testing the ability of wild-type paternal alleles to complement phenotypes conditioned by mutant maternal alleles. Our results demonstrate that wild-type paternal alleles for nine of these genes are completely functional 2 days after pollination, with the remaining 40 genes showing partial activity beginning at 2, 3 or 5 days after pollination. Using our functional assay, we also demonstrate that different hybrid combinations exhibit significant variation in paternal allele activation, reconciling the apparently contradictory results of previous transcriptional studies. The variation in timing of gene function that we observe confirms that paternal genome activation does not occur in one early discrete step, provides large-scale functional evidence that maternal and paternal genomes make non-equivalent contributions to early plant embryogenesis, and uncovers an unexpectedly profound effect of hybrid genetic backgrounds on paternal gene activity.

Myotilinopathy in a family with late onset myopathy.

PubMed

Pénisson-Besnier, Isabelle; Talvinen, Kati; Dumez, Catherine; Vihola, Anna; Dubas, Frédéric; Fardeau, Michel; Hackman, Peter; Carpen, Olli; Udd, Bjarne

2006-07-01

Mutations in titin are well known cause of late onset autosomal dominant distal myopathy. Mutations in another sarcomeric protein, myotilin, were first identified in two families with dominant limb girdle muscular phenotype. Recently, however, myotilin mutations have been associated with more distal phenotypes in patients with late onset myofibrillar myopathy. We report here a multigenerational French family in which gene sequencing identified a S60F myotilin mutation in all patients with full penetrance despite very late onset. The family was originally reported as a distal myopathy but intrafamilial variability was remarkable with proximal or distal muscle weakness or both. Extended morphological characteristics of muscle biopsy findings in myotilinopathy indicate that immunohistochemistry may be important for selection of molecular genetic approach in myofibrillar myopathy.

Identifying the pollen of an extinct spruce species in the Late Quaternary sediments of the Tunica Hills region, south-eastern United States

USGS Publications Warehouse

Luke Mander,; Jacklyn Rodriguez,; Pietra G. Mueller,; Jackson, Stephen T.; Surangi W. Punyasena,

2014-01-01

Late Quaternary fluvial deposits in the Tunica Hills region of Louisiana and Mississippi are rich in spruce macrofossils of the extinct species Picea critchfieldii, the one recognized plant extinction of the Late Quaternary. However, the morphology of P. critchfieldii pollen is unknown, presenting a barrier to the interpretation of pollen spectra from the last glacial of North America. To address this issue, we undertook a morphometric study of Picea pollen from Tunica Hills. Morphometric data, together with qualitative observations of pollen morphology using Apotome fluorescence microscopy, indicate that Picea pollen from Tunica Hills is morphologically distinct from the pollen of P. glauca, P. mariana and P. rubens. Measurements of grain length, corpus width and corpus height indicate that Picea pollen from Tunica Hills is larger than the pollen of P. mariana and P. rubens, and is slightly larger than P. glauca pollen. We argue that the morphologically distinctive Tunica Hills Picea pollen was probably produced by the extinct spruce species P. critchfieldii. These morphological differences could be used to identify P. critchfieldii in existing and newly collected pollen records, which would refine its paleoecologic and biogeographic history and clarify the nature and timing of its extinction in the Late Quaternary.

cDNA cloning, genomic organization and expression analysis during somatic embryogenesis of the translationally controlled tumor protein (TCTP) gene from Japanese larch (Larix leptolepis).

PubMed

Zhang, Li-Feng; Li, Wan-Feng; Han, Su-Ying; Yang, Wen-Hua; Qi, Li-Wang

2013-10-15

A full-length cDNA and genomic sequences of a translationally controlled tumor protein (TCTP) gene were isolated from Japanese larch (Larix leptolepis) and designated LaTCTP. The length of the cDNA was 1, 043 bp and contained a 504 bp open reading frame that encodes a predicted protein of 167 amino acids, characterized by two signature sequences of the TCTP protein family. Analysis of the LaTCTP gene structure indicated four introns and five exons, and it is the largest of all currently known TCTP genes in plants. The 5'-flanking promoter region of LaTCTP was cloned using an improved TAIL-PCR technique. In this region we identified many important potential cis-acting elements, such as a Box-W1 (fungal elicitor responsive element), a CAT-box (cis-acting regulatory element related to meristem expression), a CGTCA-motif (cis-acting regulatory element involved in MeJA-responsiveness), a GT1-motif (light responsive element), a Skn-1-motif (cis-acting regulatory element required for endosperm expression) and a TGA-element (auxin-responsive element), suggesting that expression of LaTCTP is highly regulated. Expression analysis demonstrated ubiquitous localization of LaTCTP mRNA in the roots, stems and needles, high mRNA levels in the embryonal-suspensor mass (ESM), browning embryogenic cultures and mature somatic embryos, and low levels of mRNA at day five during somatic embryogenesis. We suggest that LaTCTP might participate in the regulation of somatic embryo development. These results provide a theoretical basis for understanding the molecular regulatory mechanism of LaTCTP and lay the foundation for artificial regulation of somatic embryogenesis. © 2013.

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

PubMed Central

2013-01-01

Background It is during embryogenesis that the plant body plan is established and the meristems responsible for all post-embryonic growth are specified. The molecular mechanisms governing conifer embryogenesis are still largely unknown. Their elucidation may contribute valuable information to clarify if the distinct features of embryo development in angiosperms and gymnosperms result from differential gene regulation. To address this issue, we have performed the first transcriptomic analysis of zygotic embryo development in a conifer species (Pinus pinaster) focusing our study in particular on regulatory genes playing important roles during plant embryo development, namely epigenetic regulators and transcription factors. Results Microarray analysis of P. pinaster zygotic embryogenesis was performed at five periods of embryo development from early developing to mature embryos. Our results show that most changes in transcript levels occurred in the first and the last embryo stage-to-stage transitions, namely early to pre-cotyledonary embryo and cotyledonary to mature embryo. An analysis of functional categories for genes that were differentially expressed through embryogenesis highlighted several epigenetic regulation mechanisms. While putative orthologs of transcripts associated with mechanisms that target transposable elements and repetitive sequences were strongly expressed in early embryogenesis, PRC2-mediated repression of genes seemed more relevant during late embryogenesis. On the other hand, functions related to sRNA pathways appeared differentially regulated across all stages of embryo development with a prevalence of miRNA functions in mid to late embryogenesis. Identification of putative transcription factor genes differentially regulated between consecutive embryo stages was strongly suggestive of the relevance of auxin responses and regulation of auxin carriers during early embryogenesis. Such responses could be involved in establishing embryo patterning

High Genetic and Epigenetic Stability in Coffea arabica Plants Derived from Embryogenic Suspensions and Secondary Embryogenesis as Revealed by AFLP, MSAP and the Phenotypic Variation Rate

PubMed Central

Bobadilla Landey, Roberto; Cenci, Alberto; Georget, Frédéric; Bertrand, Benoît; Camayo, Gloria; Dechamp, Eveline; Herrera, Juan Carlos; Santoni, Sylvain; Lashermes, Philippe; Simpson, June; Etienne, Hervé

2013-01-01

Embryogenic suspensions that involve extensive cell division are risky in respect to genome and epigenome instability. Elevated frequencies of somaclonal variation in embryogenic suspension-derived plants were reported in many species, including coffee. This problem could be overcome by using culture conditions that allow moderate cell proliferation. In view of true-to-type large-scale propagation of C. arabica hybrids, suspension protocols based on low 2,4-D concentrations and short proliferation periods were developed. As mechanisms leading to somaclonal variation are often complex, the phenotypic, genetic and epigenetic changes were jointly assessed so as to accurately evaluate the conformity of suspension-derived plants. The effects of embryogenic suspensions and secondary embryogenesis, used as proliferation systems, on the genetic conformity of somatic embryogenesis-derived plants (emblings) were assessed in two hybrids. When applied over a 6 month period, both systems ensured very low somaclonal variation rates, as observed through massive phenotypic observations in field plots (0.74% from 200 000 plant). Molecular AFLP and MSAP analyses performed on 145 three year-old emblings showed that polymorphism between mother plants and emblings was extremely low, i.e. ranges of 0–0.003% and 0.07–0.18% respectively, with no significant difference between the proliferation systems for the two hybrids. No embling was found to cumulate more than three methylation polymorphisms. No relation was established between the variant phenotype (27 variants studied) and a particular MSAP pattern. Chromosome counting showed that 7 of the 11 variant emblings analyzed were characterized by the loss of 1–3 chromosomes. This work showed that both embryogenic suspensions and secondary embryogenesis are reliable for true-to-type propagation of elite material. Molecular analyses revealed that genetic and epigenetic alterations are particularly limited during coffee somatic

Enhanced Indirect Somatic Embryogenesis of Date Palm Using Low Levels of Seawater.

PubMed

Taha, Rania A

2017-01-01

Date palm tolerates salinity, drought, and high temperatures. Arid and semiarid zones, especially the Middle East region, need a huge number of date palms for cultivation. To meet this demand, tissue culture techniques have great potential for mass production of plantlets, especially using the indirect embryogenesis technique; any improvement of these techniques is a worthy objective. Low levels of salinity can enhance growth and development of tolerant plants. A low level of seawater, a natural source of salinity, reduces the time required for micropropagation processes of date palm cv. Malkaby when added to MS medium. Medium containing seawater at 500 ppm total dissolved solid (TDS) (12.2 mL/L) improves callus proliferation, whereas 1500 ppm (36.59 mL/L) enhances plant regeneration including multiplication of secondary embryos, embryo germination, and rooting.

Spatio-Temporal Accumulation and Activity of Calcium-Dependent Protein Kinases during Embryogenesis, Seed Development, and Germination in Sandalwood1

PubMed Central

Anil, Veena S.; Harmon, Alice C.; Rao, K. Sankara

2000-01-01

Western-blot analysis and protein kinase assays identified two Ca2+-dependent protein kinases (CDPKs) of 55 to 60 kD in soluble protein extracts of embryogenic cultures of sandalwood (Santalum album L.). However, these sandalwood CDPKs (swCDPKs) were absent in plantlets regenerated from somatic embryos. swCDPKs exhibited differential expression (monitored at the level of the protein) and activity in different developmental stages. Zygotic embryos, seedlings, and endosperm showed high accumulation of swCDPK, but the enzyme was not detected in the soluble proteins of shoots and flowers. swCDPK exhibited a temporal pattern of expression in endosperm, showing high accumulation and activity in mature fruit and germinating stages; the enzyme was localized strongly in the storage bodies of the endosperm cells. The study also reports for the first time to our knowledge a post-translational inhibition/inactivation of swCDPK in zygotic embryos during seed dormancy and early stages of germination. The temporal expression of swCDPK during somatic/zygotic embryogenesis, seed maturation, and germination suggests involvement of the enzyme in these developmental processes. PMID:10759499

In Vitro Fertilization with Isolated, Single Gametes Results in Zygotic Embryogenesis and Fertile Maize Plants.

PubMed Central

Kranz, E; Lorz, H

1993-01-01

We demonstrate here the possibility of regenerating phenotypically normal, fertile maize plants via in vitro fertilization of isolated, single sperm and egg cells mediated by electrofusion. The technique leads to the highly efficient formation of polar zygotes, globular structures, proembryos, and transition-phase embryos and to the formation of plants from individually cultured fusion products. Regeneration of plants occurs via embryogenesis and occasionally by polyembryony and organogenesis. Flowering plants can be obtained within 100 days of gamete fusion. Regenerated plants were studied by karyological and morphological analyses, and the segregation of kernel color was determined. The hybrid nature of the plants was confirmed. PMID:12271084

Identifying the ionically bound cell wall and intracellular glycoside hydrolases in late growth stage Arabidopsis stems: implications for the genetic engineering of bioenergy crops

PubMed Central

Wei, Hui; Brunecky, Roman; Donohoe, Bryon S.; Ding, Shi-You; Ciesielski, Peter N.; Yang, Shihui; Tucker, Melvin P.; Himmel, Michael E.

2015-01-01

Identifying the cell wall-ionically bound glycoside hydrolases (GHs) in Arabidopsis stems is important for understanding the regulation of cell wall integrity. For cell wall proteomics studies, the preparation of clean cell wall fractions is a challenge since cell walls constitute an open compartment, which is more likely to contain a mixture of intracellular and extracellular proteins due to cell leakage at the late growth stage. Here, we utilize a CaCl2-extraction procedure to isolate non-structural proteins from Arabidopsis whole stems, followed by the in-solution and in-gel digestion methods coupled with Nano-LC-MS/MS, bioinformatics and literature analyses. This has led to the identification of 75 proteins identified using the in-solution method and 236 proteins identified by the in-gel method, among which about 10% of proteins predicted to be secreted. Together, eight cell wall proteins, namely AT1G75040, AT5G26000, AT3G57260, AT4G21650, AT3G52960, AT3G49120, AT5G49360, and AT3G14067, were identified by the in-solution method; among them, three were the GHs (AT5G26000, myrosinase 1, GH1; AT3G57260, β-1,3-glucanase 2, GH17; AT5G49360, bifunctional XYL 1/α-L-arabinofuranosidase, GH3). Moreover, four more GHs: AT4G30270 (xyloglucan endotransferase, GH16), AT1G68560 (bifunctional α-l-arabinofuranosidase/XYL, GH31), AT1G12240 (invertase, GH32) and AT2G28470 (β-galactosidase 8, GH35), were identified by the in-gel solution method only. Notably, more than half of above identified GHs are xylan- or hemicellulose-modifying enzymes, and will likely have an impact on cellulose accessibility, which is a critical factor for downstream enzymatic hydrolysis of plant tissues for biofuels production. The implications of these cell wall proteins identified at the late growth stage for the genetic engineering of bioenergy crops are discussed. PMID:26029221

Identifying the ionically bound cell wall and intracellular glycoside hydrolases in late growth stage Arabidopsis stems: implications for the genetic engineering of bioenergy crops.

PubMed

Wei, Hui; Brunecky, Roman; Donohoe, Bryon S; Ding, Shi-You; Ciesielski, Peter N; Yang, Shihui; Tucker, Melvin P; Himmel, Michael E

2015-01-01

Identifying the cell wall-ionically bound glycoside hydrolases (GHs) in Arabidopsis stems is important for understanding the regulation of cell wall integrity. For cell wall proteomics studies, the preparation of clean cell wall fractions is a challenge since cell walls constitute an open compartment, which is more likely to contain a mixture of intracellular and extracellular proteins due to cell leakage at the late growth stage. Here, we utilize a CaCl2-extraction procedure to isolate non-structural proteins from Arabidopsis whole stems, followed by the in-solution and in-gel digestion methods coupled with Nano-LC-MS/MS, bioinformatics and literature analyses. This has led to the identification of 75 proteins identified using the in-solution method and 236 proteins identified by the in-gel method, among which about 10% of proteins predicted to be secreted. Together, eight cell wall proteins, namely AT1G75040, AT5G26000, AT3G57260, AT4G21650, AT3G52960, AT3G49120, AT5G49360, and AT3G14067, were identified by the in-solution method; among them, three were the GHs (AT5G26000, myrosinase 1, GH1; AT3G57260, β-1,3-glucanase 2, GH17; AT5G49360, bifunctional XYL 1/α-L-arabinofuranosidase, GH3). Moreover, four more GHs: AT4G30270 (xyloglucan endotransferase, GH16), AT1G68560 (bifunctional α-l-arabinofuranosidase/XYL, GH31), AT1G12240 (invertase, GH32) and AT2G28470 (β-galactosidase 8, GH35), were identified by the in-gel solution method only. Notably, more than half of above identified GHs are xylan- or hemicellulose-modifying enzymes, and will likely have an impact on cellulose accessibility, which is a critical factor for downstream enzymatic hydrolysis of plant tissues for biofuels production. The implications of these cell wall proteins identified at the late growth stage for the genetic engineering of bioenergy crops are discussed.

Identifying the ionically bound cell wall and intracellular glycoside hydrolases in late growth stage Arabidopsis stems: Implications for the genetic engineering of bioenergy crops

DOE PAGES

Wei, Hui; Brunecky, Roman; Donohoe, Bryon S.; ...

2015-05-13

Identifying the cell wall-ionically bound glycoside hydrolases (GHs) in Arabidopsis stems is important for understanding the regulation of cell wall integrity. For cell wall proteomics studies, the preparation of clean cell wall fractions is a challenge since cell walls constitute an open compartment, which is more likely to contain a mixture of intracellular and extracellular proteins due to cell leakage at the late growth stage. Here, for this study, we utilize a CaCl 2-extraction procedure to isolate non-structural proteins from Arabidopsis whole stems, followed by the in-solution and in-gel digestion methods coupled with Nano-LC-MS/MS, bioinformatics and literature analyses. This hasmore » led to the identification of 75 proteins identified using the in-solution method and 236 proteins identified by the in-gel method, among which about 10% of proteins predicted to be secreted. Together, eight cell wall proteins, namely AT1G75040, AT5G26000, AT3G57260, AT4G21650, AT3G52960, AT3G49120, AT5G49360, and AT3G14067, were identified by the in-solution method; among them, three were the GHs (AT5G26000, myrosinase 1, GH1; AT3G57260, β-1,3-glucanase 2, GH17; AT5G49360, bifunctional XYL 1/α-L-arabinofuranosidase, GH3). Moreover, four more GHs: AT4G30270 (xyloglucan endotransferase, GH16), AT1G68560 (bifunctional α-l-arabinofuranosidase/XYL, GH31), AT1G12240 (invertase, GH32) and AT2G28470 (β-galactosidase 8, GH35), were identified by the in-gel solution method only. Notably, more than half of above identified GHs are xylan- or hemicellulose-modifying enzymes, and will likely have an impact on cellulose accessibility, which is a critical factor for downstream enzymatic hydrolysis of plant tissues for biofuels production. Finally, the implications of these cell wall proteins identified at the late growth stage for the genetic engineering of bioenergy crops are discussed.« less

Identifying the ionically bound cell wall and intracellular glycoside hydrolases in late growth stage Arabidopsis stems: Implications for the genetic engineering of bioenergy crops

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

Wei, Hui; Brunecky, Roman; Donohoe, Bryon S.

Identifying the cell wall-ionically bound glycoside hydrolases (GHs) in Arabidopsis stems is important for understanding the regulation of cell wall integrity. For cell wall proteomics studies, the preparation of clean cell wall fractions is a challenge since cell walls constitute an open compartment, which is more likely to contain a mixture of intracellular and extracellular proteins due to cell leakage at the late growth stage. Here, for this study, we utilize a CaCl 2-extraction procedure to isolate non-structural proteins from Arabidopsis whole stems, followed by the in-solution and in-gel digestion methods coupled with Nano-LC-MS/MS, bioinformatics and literature analyses. This hasmore » led to the identification of 75 proteins identified using the in-solution method and 236 proteins identified by the in-gel method, among which about 10% of proteins predicted to be secreted. Together, eight cell wall proteins, namely AT1G75040, AT5G26000, AT3G57260, AT4G21650, AT3G52960, AT3G49120, AT5G49360, and AT3G14067, were identified by the in-solution method; among them, three were the GHs (AT5G26000, myrosinase 1, GH1; AT3G57260, β-1,3-glucanase 2, GH17; AT5G49360, bifunctional XYL 1/α-L-arabinofuranosidase, GH3). Moreover, four more GHs: AT4G30270 (xyloglucan endotransferase, GH16), AT1G68560 (bifunctional α-l-arabinofuranosidase/XYL, GH31), AT1G12240 (invertase, GH32) and AT2G28470 (β-galactosidase 8, GH35), were identified by the in-gel solution method only. Notably, more than half of above identified GHs are xylan- or hemicellulose-modifying enzymes, and will likely have an impact on cellulose accessibility, which is a critical factor for downstream enzymatic hydrolysis of plant tissues for biofuels production. Finally, the implications of these cell wall proteins identified at the late growth stage for the genetic engineering of bioenergy crops are discussed.« less

The effects of thermal manipulations during embryogenesis of broiler chicks on growth of embryo and skeletal traits

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

Aygün, Ali, E-mail: aaygun@selcuk.edu.tr; Narinç, Doğan, E-mail: narincd@gmail.com

Incubation temperature is one of the important environmental factors that can induce epigenetic thermal adaptation of different physiological control systems. Thus, post hatch thermo tolerance ability of birds may be gained using these manipulations during different incubation periods. The current study was carried out to reveal the effects of temperature manipulations during early and late embryogenesis on weight of embryo and size of skeletal bilateral traits (face, wings, metatarsus, tibia, and femur) in broiler chicken embryos. One thousand commercial broiler eggs from 46 week old breeder flock were used in study. Treatments consisted of eggs incubated at 37.8°C and 55%more » relative humidity throughout (control; DG1), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 0 to 8 (DG2), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 10 to 18 (DG3), heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 8 to 10 (DG4), and heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 16 to 18 (DG5). Measurements of embryo weight and bilateral traits were obtained at 20 day of incubation and at hatch (at day 21). It was determined that the live weights of embryo and chick were affected significantly by treatment; DG3 group has shown higher mean values than the other treatment groups (P<0.05). There were differences in lengths of femur, tibia and metatarsus among treatment groups at hatch. Particularly, the high incubator temperatures at the second half of incubation accelerated growth of body and bone in embryos. These consequences of the treatments performed at different temperatures and times indicate that the different metabolic shifts realized by the embryos.« less

The effects of thermal manipulations during embryogenesis of broiler chicks on growth of embryo and skeletal traits

NASA Astrophysics Data System (ADS)

Aygün, Ali; Narinç, Doǧan

2016-04-01

Incubation temperature is one of the important environmental factors that can induce epigenetic thermal adaptation of different physiological control systems. Thus, post hatch thermo tolerance ability of birds may be gained using these manipulations during different incubation periods. The current study was carried out to reveal the effects of temperature manipulations during early and late embryogenesis on weight of embryo and size of skeletal bilateral traits (face, wings, metatarsus, tibia, and femur) in broiler chicken embryos. One thousand commercial broiler eggs from 46 week old breeder flock were used in study. Treatments consisted of eggs incubated at 37.8°C and 55% relative humidity throughout (control; DG1), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 0 to 8 (DG2), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 10 to 18 (DG3), heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 8 to 10 (DG4), and heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 16 to 18 (DG5). Measurements of embryo weight and bilateral traits were obtained at 20 day of incubation and at hatch (at day 21). It was determined that the live weights of embryo and chick were affected significantly by treatment; DG3 group has shown higher mean values than the other treatment groups (P<0.05). There were differences in lengths of femur, tibia and metatarsus among treatment groups at hatch. Particularly, the high incubator temperatures at the second half of incubation accelerated growth of body and bone in embryos. These consequences of the treatments performed at different temperatures and times indicate that the different metabolic shifts realized by the embryos.

Pragmatic Functions of Toddlers Who Are Late Talkers

ERIC Educational Resources Information Center

MacRoy-Higgins, Michelle; Kaufman, Ilana

2012-01-01

Toddlers who are "late talkers" demonstrate reduced expressive vocabulary in the absence of physical, social, cognitive, or sensory impairment; they are usually identified at age 2, when they produce fewer than 50 words and do not combine words (Rescorla, 1989). This study analyzed spontaneous language samples of 10 late talking toddlers and 11…

Center variation in the delivery of indicated late preterm births

PubMed Central

Aliaga, Sofia; Zhang, Jun; Long, D. Leann; Herring, Amy H.; Laughon, Matthew; Boggess, Kim; Reddy, Uma M.; Grantz, Katherine Laughon

2016-01-01

Objective Evidence for optimal timing of delivery for some pregnancy complications at late preterm gestation is limited. The purpose of this study was to identify center variation of indicated late preterm births. Study design Analysis of singleton late preterm and term births from a large U.S. retrospective obstetrical cohort. Births associated with spontaneous preterm labor, major congenital anomalies, chorioamnionitis, and emergency cesarean were excluded. We used modified Poisson fixed effects logistic regression with interaction terms to assess center variation of indicated late preterm births associated with four medical/obstetric comorbidities after adjusting for socio-demographics, co-morbidities, and hospital/provider characteristics. Results We identified 150,055 births from 16 hospitals; 9218 were indicated late preterm births. We found wide variation of indicated late preterm births across hospitals. The extent of center variation was greater for births associated with preterm premature rupture of membranes (RR across sites: 0.45 – 3.05), hypertensive disorders of pregnancy (RR across sites: 0.36 – 1.27), and placenta previa/abruption (RR across sites: 0.48 – 1.82). We found less center variation for births associated with diabetes (RR across sites: 0.65 – 1.39). Conclusion Practice variation in the management of indicated late preterm deliveries might be a source of preventable late preterm birth. PMID:27120474

Meta-analysis of Genome Wide Association Studies Identifies Genetic Markers of Late Toxicity Following Radiotherapy for Prostate Cancer.

PubMed

Kerns, Sarah L; Dorling, Leila; Fachal, Laura; Bentzen, Søren; Pharoah, Paul D P; Barnes, Daniel R; Gómez-Caamaño, Antonio; Carballo, Ana M; Dearnaley, David P; Peleteiro, Paula; Gulliford, Sarah L; Hall, Emma; Michailidou, Kyriaki; Carracedo, Ángel; Sia, Michael; Stock, Richard; Stone, Nelson N; Sydes, Matthew R; Tyrer, Jonathan P; Ahmed, Shahana; Parliament, Matthew; Ostrer, Harry; Rosenstein, Barry S; Vega, Ana; Burnet, Neil G; Dunning, Alison M; Barnett, Gillian C; West, Catharine M L

2016-08-01

Nearly 50% of cancer patients undergo radiotherapy. Late radiotherapy toxicity affects quality-of-life in long-term cancer survivors and risk of side-effects in a minority limits doses prescribed to the majority of patients. Development of a test predicting risk of toxicity could benefit many cancer patients. We aimed to meta-analyze individual level data from four genome-wide association studies from prostate cancer radiotherapy cohorts including 1564 men to identify genetic markers of toxicity. Prospectively assessed two-year toxicity endpoints (urinary frequency, decreased urine stream, rectal bleeding, overall toxicity) and single nucleotide polymorphism (SNP) associations were tested using multivariable regression, adjusting for clinical and patient-related risk factors. A fixed-effects meta-analysis identified two SNPs: rs17599026 on 5q31.2 with urinary frequency (odds ratio [OR] 3.12, 95% confidence interval [CI] 2.08-4.69, p-value 4.16×10(-8)) and rs7720298 on 5p15.2 with decreased urine stream (OR 2.71, 95% CI 1.90-3.86, p-value=3.21×10(-8)). These SNPs lie within genes that are expressed in tissues adversely affected by pelvic radiotherapy including bladder, kidney, rectum and small intestine. The results show that heterogeneous radiotherapy cohorts can be combined to identify new moderate-penetrance genetic variants associated with radiotherapy toxicity. The work provides a basis for larger collaborative efforts to identify enough variants for a future test involving polygenic risk profiling. Copyright © 2016 The Ohio State University Wexner Medical Center. Published by Elsevier B.V. All rights reserved.

Mitotic waves in the early embryogenesis of Drosophila: Bistability traded for speed.

PubMed

Vergassola, Massimo; Deneke, Victoria E; Di Talia, Stefano

2018-03-06

Early embryogenesis of most metazoans is characterized by rapid and synchronous cleavage divisions. Chemical waves of Cdk1 activity were previously shown to spread across Drosophila embryos, and the underlying molecular processes were dissected. Here, we present the theory of the physical mechanisms that control Cdk1 waves in Drosophila The in vivo dynamics of Cdk1 are captured by a transiently bistable reaction-diffusion model, where time-dependent reaction terms account for the growing level of cyclins and Cdk1 activation across the cell cycle. We identify two distinct regimes. The first one is observed in mutants of the mitotic switch. There, waves are triggered by the classical mechanism of a stable state invading a metastable one. Conversely, waves in wild type reflect a transient phase that preserves the Cdk1 spatial gradients while the overall level of Cdk1 activity is swept upward by the time-dependent reaction terms. This unique mechanism generates a wave-like spreading that differs from bistable waves for its dependence on dynamic parameters and its faster speed. Namely, the speed of "sweep" waves strikingly decreases as the strength of the reaction terms increases and scales as the powers 3/4, -1/2, and 7/12 of Cdk1 molecular diffusivity, noise amplitude, and rate of increase of Cdk1 activity in the cell-cycle S phase, respectively. Theoretical predictions are supported by numerical simulations and experiments that couple quantitative measurements of Cdk1 activity and genetic perturbations of the accumulation rate of cyclins. Finally, our analysis bears upon the inhibition required to suppress Cdk1 waves at the cell-cycle pause for the maternal-to-zygotic transition.

Reproductive effects of the water-accommodated fraction of a natural gas condensate in the Indo-Pacific reef-building coral Pocillopora damicornis.

PubMed

Villanueva, R D; Yap, H T; Montaño, M N E

2011-11-01

Toxic effects of the water-accommodated fraction (WAF) of a natural gas condensate on the reproduction of the brooding coral Pocillopora damicornis were studied in short-term (24 h) laboratory experiments. Coral fragments were exposed to varying concentrations of condensate WAF during different reproductive phases: gametogenesis, early embryogenesis, and late embryogenesis (when nighttime planulation occurs). During gametogenesis, exposure to condensate WAF did not inhibit subsequent production of larvae. On the other hand, exposure to >25% WAF of gravid corals, at early and late embryogenesis, resulted in abortion and early release of larvae, respectively, with higher percentages of larvae expelled in fragments treated with higher concentrations of condensate WAF at least 3h after onset of exposure. Aborted larvae during early embryogenesis were 'premature', as they are of small size (0.06±0.03 mm³), low metamorphic competency (54%), and white in coloration, with a pale brown oral end (indicating low density of zooxanthellae). Those larvae released at the latter part of embryogenesis are bigger in size (0.22±0.08 mm³), possess 100% metamorphic competency, and are brown in coloration (high density of zooxanthellae). Aside from direct effects on reproduction, fragment mortality index was higher in samples exposed to higher concentrations of condensate WAF (>25%), hence lowering the number of potentially reproducing polyps. Altogether, exposure to >25% natural gas condensate WAF for at least 3h can potentially disrupt the replenishment of coral populations due to negative effects on reproduction and early life processes. Copyright © 2011 Elsevier Inc. All rights reserved.

Working with Students Who Are Late-Deafened. PEPNet Tipsheet

ERIC Educational Resources Information Center

Clark, Mary

2010-01-01

Late-deafness means deafness that happened postlingually, any time after the development of speech and language in a person who has identified with hearing society through schooling, social connections, etc. Students who are late-deafened cannot understand speech without visual aids such as speechreading, sign language, and captioning (although…

Hypothyroidism in late-onset Pompe disease.

PubMed

Schneider, Joseph; Burmeister, Lynn A; Rudser, Kyle; Whitley, Chester B; Jarnes Utz, Jeanine

2016-09-01

In Pompe disease, a deficiency of acid α-glucosidase enzyme activity leads to pathologic accumulation of glycogen in tissues. Phenotype heterogeneity in Pompe includes an infantile form and late-onset forms (juvenile- and adult-onset forms). Symptoms common to all phenotypes include progressive muscle weakness and worsening respiratory function. Patients with late-onset forms of Pompe disease commonly complain of chronic fatigue and generalized muscle weakness prior to being diagnosed with Pompe disease, and this may lead to consideration of hypothyroidism in the differential diagnosis. This study aimed to evaluate the prevalence of hypothyroidism in the adult-onset form of Pompe disease. Electronic chart review was performed at the Advanced Therapies Clinic at the University of Minnesota Medical Center (UMMC) to identify patients with late-onset Pompe disease. The identified charts were reviewed for a co-diagnosis of hypothyroidism. A query was made to the clinical data repository at UMMC searching diagnosis ICD9 code 244.9 (hypothyroidism not otherwise specified) and/or presence of levothyroxine from 2011 to 2014 in patients 18 years of age and older. The clinical data repository found a prevalence of hypothyroidism of 3.15% (56,072 of 1,782,720 patients) in the adult patient population at UMMC. Ten adult patients with Pompe disease were identified, five with the diagnosis of hypothyroidism (50%, 95% CI: 23.7, 76.3, p < 0.001 compared with the general UMMC adult population). Hypothyroidism was found at a higher prevalence in patients with late-onset Pompe disease compared to the general adult population at UMMC. Studies in larger populations of patients with Pompe disease would be needed to confirm an association of Pompe disease and hypothyroidism. Challenges include finding an adequate sample size, due the rarity of Pompe disease.

Ossicular fusion and cholesteatoma in auriculo-condylar syndrome: in vivo evidence of arrest of embryogenesis.

PubMed

Propst, Evan J; Ngan, Bo Y; Mount, Richard J; Martin-Munoz, Daniel; Blaser, Susan; Harrison, Robert V; Cushing, Sharon L; Papsin, Blake C

2013-02-01

Auriculo-condylar syndrome (ACS) is a rare condition affecting first branchial arch structures. The types of hearing loss and temporal bone findings in ACS have not been reported. We describe a 14-year-old male with constricted pinnae, mandibular dysostosis, glossoptosis, a high-arched palate, hearing loss, and cholesteatoma. Computed tomography imaging demonstrated malleoincudal joint ankylosis. The fused malleoincudal complex was removed during mastoidectomy for cholesteatoma. Electron microscopy and histopathology of the joint suggested the fusion was congenital. This is the first report of ossicular fusion and cholesteatoma in ACS and the most detailed in vivo evidence of disruption of embryogenesis during malleoincudal joint formation. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Plant Regeneration and Somatic Embryogenesis from Immature Embryos Derived through Interspecific Hybridization among Different Carica Species

PubMed Central

Azad, Md. Abul Kalam; Rabbani, Md. Golam; Amin, Latifah

2012-01-01

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F1 plantlets confirmed the presence of the hybrid plantlets. PMID:23235330

Timing of Tissue-specific Cell Division Requires a Differential Onset of Zygotic Transcription during Metazoan Embryogenesis*

PubMed Central

Wong, Ming-Kin; Guan, Daogang; Ng, Kaoru Hon Chun; Ho, Vincy Wing Sze; An, Xiaomeng; Li, Runsheng; Ren, Xiaoliang

2016-01-01

Metazoan development demands not only precise cell fate differentiation but also accurate timing of cell division to ensure proper development. How cell divisions are temporally coordinated during development is poorly understood. Caenorhabditis elegans embryogenesis provides an excellent opportunity to study this coordination due to its invariant development and widespread division asynchronies. One of the most pronounced asynchronies is a significant delay of cell division in two endoderm progenitor cells, Ea and Ep, hereafter referred to as E2, relative to its cousins that mainly develop into mesoderm organs and tissues. To unravel the genetic control over the endoderm-specific E2 division timing, a total of 822 essential and conserved genes were knocked down using RNAi followed by quantification of cell cycle lengths using in toto imaging of C. elegans embryogenesis and automated lineage. Intriguingly, knockdown of numerous genes encoding the components of general transcription pathway or its regulatory factors leads to a significant reduction in the E2 cell cycle length but an increase in cell cycle length of the remaining cells, indicating a differential requirement of transcription for division timing between the two. Analysis of lineage-specific RNA-seq data demonstrates an earlier onset of transcription in endoderm than in other germ layers, the timing of which coincides with the birth of E2, supporting the notion that the endoderm-specific delay in E2 division timing demands robust zygotic transcription. The reduction in E2 cell cycle length is frequently associated with cell migration defect and gastrulation failure. The results suggest that a tissue-specific transcriptional activation is required to coordinate fate differentiation, division timing, and cell migration to ensure proper development. PMID:27056332

Somatic Embryogenesis in Coffee: The Evolution of Biotechnology and the Integration of Omics Technologies Offer Great Opportunities

PubMed Central

Campos, Nádia A.; Panis, Bart; Carpentier, Sebastien C.

2017-01-01

One of the most important crops cultivated around the world is coffee. There are two main cultivated species, Coffea arabica and C. canephora. Both species are difficult to improve through conventional breeding, taking at least 20 years to produce a new cultivar. Biotechnological tools such as genetic transformation, micropropagation and somatic embryogenesis (SE) have been extensively studied in order to provide practical results for coffee improvement. While genetic transformation got many attention in the past and is booming with the CRISPR technology, micropropagation and SE are still the major bottle neck and urgently need more attention. The methodologies to induce SE and the further development of the embryos are genotype-dependent, what leads to an almost empirical development of specific protocols for each cultivar or clone. This is a serious limitation and excludes a general comprehensive understanding of the process as a whole. The aim of this review is to provide an overview of which achievements and molecular insights have been gained in (coffee) somatic embryogenesis and encourage researchers to invest further in the in vitro technology and combine it with the latest omics techniques (genomics, transcriptomics, proteomics, metabolomics, and phenomics). We conclude that the evolution of biotechnology and the integration of omics technologies offer great opportunities to (i) optimize the production process of SE and the subsequent conversion into rooted plantlets and (ii) to screen for possible somaclonal variation. However, currently the usage of the latest biotechnology did not pass the stage beyond proof of potential and needs to further improve. PMID:28871271

Gene expression and metabolite profiling of gibberellin biosynthesis during induction of somatic embryogenesis in Medicago truncatula Gaertn

PubMed Central

Igielski, Rafał

2017-01-01

Gibberellins (GAs) are involved in the regulation of numerous developmental processes in plants including zygotic embryogenesis, but their biosynthesis and role during somatic embryogenesis (SE) is mostly unknown. In this study we show that during three week- long induction phase, when cells of leaf explants from non-embryogenic genotype (M9) and embryogenic variant (M9-10a) were forming the callus, all the bioactive gibberellins from non-13-hydroxylation (GA4, GA7) and 13-hydroxylation (GA1, GA5, GA3, GA6) pathways were present, but the contents of only a few of them differed between the tested lines. The GA53 and GA19 substrates synthesized by the 13-hydroxylation pathway accumulated specifically in the M9-10a line after the first week of induction; subsequently, among the bioactive gibberellins detected, only the content of GA3 increased and appeared to be connected with acquisition of embryogenic competence. We fully annotated 20 Medicago truncatula orthologous genes coding the enzymes which catalyze all the known reactions of gibberellin biosynthesis. Our results indicate that, within all the genes tested, expression of only three: MtCPS, MtGA3ox1 and MtGA3ox2, was specific to embryogenic explants and reflected the changes observed in GA53, GA19 and GA3 contents. Moreover, by analyzing expression of MtBBM, SE marker gene, we confirmed the inhibitory effect of manipulation in GAs metabolism, applying exogenous GA3, which not only impaired the production of somatic embryos, but also significantly decreased expression of this gene. PMID:28750086

Heat shock protein 83 plays pleiotropic roles in embryogenesis, longevity, and fecundity of the pea aphid Acyrthosiphon pisum.

PubMed

Will, Torsten; Schmidtberg, Henrike; Skaljac, Marisa; Vilcinskas, Andreas

2017-01-01

Heat shock protein 83 (HSP83) is homologous to the chaperone HSP90. It has pleiotropic functions in Drosophila melanogaster, including the control of longevity and fecundity, and facilitates morphological evolution by buffering cryptic deleterious mutations in wild populations. In the pea aphid Acyrthosiphon pisum, HSP83 expression is moderately induced by bacterial infection but upregulated more strongly in response to heat stress and fungal infection. Stress-inducible heat shock proteins are of considerable evolutionary and ecological importance because they are known to buffer environmental variation and to influence fitness under non-optimal conditions. To investigate the functions of HSP83 in viviparous aphids, we used RNA interference to attenuate its expression and studied the impact on complex parameters. The RNA interference (RNAi)-mediated depletion of HSP83 expression in A. pisum reduced both longevity and fecundity, suggesting this chaperone has an evolutionarily conserved function in insects. Surprisingly, HSP83 depletion reduced the number of viviparous offspring while simultaneously increasing the number of premature nymphs developing in the ovaries, suggesting an unexpected role in aphid embryogenesis and eclosion. The present study indicates that reduced HSP83 expression in A. pisum reveals both functional similarities and differences compared with its reported roles in holometabolous insects. Its impact on aphid lifespan, fecundity, and embryogenesis suggests a function that determines their fitness. This could be achieved by targeting different client proteins, recruiting distinct co-chaperones or transposon activation.

Regulatory function of homeodomain-leucine zipper (HD-ZIP) family proteins during embryogenesis.

PubMed

Roodbarkelari, Farshad; Groot, Edwin P

2017-01-01

Homeodomain-leucine zipper proteins (HD-ZIPs) form a plant-specific family of transcription factors functioning as homo- or heterodimers. Certain members of all four classes of this family are involved in embryogenesis, the focus of this review. They support auxin biosynthesis, transport and response, which are in turn essential for the apical-basal patterning of the embryo, radicle formation and outgrowth of the cotyledons. They transcriptionally regulate meristem regulators to maintain the shoot apical meristem once it is initiated. Some members are specific to the protoderm, the outermost layer of the embryo, and play a role in shoot apical meristem function. Within classes, homeodomain-leucine zippers tend to act redundantly during embryo development, and there are many examples of regulation within and between classes of homeodomain-leucine zippers. This indicates a complex network of regulation that awaits future experiments to uncover. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Morphology and Syntax in Late Talkers at Age 5

ERIC Educational Resources Information Center

Rescorla, Leslie; Turner, Hannah L.

2015-01-01

Purpose: This study reports age 5 morphology and syntax skills in late talkers identified at age 2 (n = 34) and typically developing comparison children (n = 20). Results: The late talkers manifested significant morphological delays at ages 3 and 4 relative to comparison peers. Based on the 14 morphemes analyzed at age 5, the only significant…

Pretreatments, conditioned medium and co-culture increase the incidence of somatic embryogenesis of different Cichorium species

PubMed Central

Couillerot, Jean-Paul; Windels, David; Vazquez, Franck; Michalski, Jean-Claude; Hilbert, Jean-Louis; Blervacq, Anne-Sophie

2012-01-01

Somatic embryogenesis (SE) in Cichorium involves dedifferentiation and redifferentiation of single cells and can be induced by specific in vitro culture conditions. We have tested the effect of various treatments on the incidence of SE (ISE) of an interspecific embryogenic hybrid (C. endivia x C. intybus) and of different commercial chicories (C. endivia and C. intybus) that are typically recalcitrant to SE in standard culture conditions. We found that the ISE of the hybrid is significantly increased by pretreatment of tissues by submersion in solutions of glycerol, abscisic acid, spermine, putrescine or of combinations of these compounds. Interestingly, the most efficient of these pretreatments also had an unexpectedly high effect on the ISE of the C. intybus cultivars. The ISE of the hybrid and of the commercial chicories were increased when explants were co-cultured with highly embryogenic chicory explants or when they were cultured in conditioned medium. These observations established that unidentified SE-promoting factors are released in the culture medium. HPLC analyses of secreted Arabino-Galactan Proteins (AGPs), which are known to stimulate SE, did not allow identifying a fraction containing differentially abundant AGP candidates. However, pointing to their role in promoting SE, we found that the hybrid had a drastically higher ISE when amino sugars and L-Proline, the putative precursors of secreted AGPs, were both added to the medium. PMID:22301978

The significance of PIWI family expression in human lung embryogenesis and non-small cell lung cancer.

PubMed

Navarro, Alfons; Tejero, Rut; Viñolas, Nuria; Cordeiro, Anna; Marrades, Ramon M; Fuster, Dolors; Caritg, Oriol; Moises, Jorge; Muñoz, Carmen; Molins, Laureano; Ramirez, Josep; Monzo, Mariano

2015-10-13

The expression of Piwi-interacting RNAs, small RNAs that bind to PIWI proteins, was until recently believed to be limited to germinal stem cells. We have studied the expression of PIWI genes during human lung embryogenesis and in paired tumor and normal tissue prospectively collected from 71 resected non-small-cell lung cancer patients. The mRNA expression analysis showed that PIWIL1 was highly expressed in 7-week embryos and downregulated during the subsequent weeks of development. PIWIL1 was expressed in 11 of the tumor samples but in none of the normal tissue samples. These results were validated by immunohistochemistry, showing faint cytoplasmic reactivity in the PIWIL1-positive samples. Interestingly, the patients expressing PIWIL1 had a shorter time to relapse (TTR) (p = 0.006) and overall survival (OS) (p = 0.0076) than those without PIWIL1 expression. PIWIL2 and 4 were downregulated in tumor tissue in comparison to the normal tissue (p < 0.001) and the patients with lower levels of PIWIL4 had shorter TTR (p = 0.048) and OS (p = 0.033). In the multivariate analysis, PIWIL1 expression emerged as an independent prognostic marker. Using 5-Aza-dC treatment and bisulfite sequencing, we observed that PIWIL1 expression could be regulated in part by methylation. Finally, an in silico study identified a stem-cell expression signature associated with PIWIL1 expression.

Excess caffeine exposure impairs eye development during chick embryogenesis

PubMed Central

Ma, Zheng-lai; Wang, Guang; Cheng, Xin; Chuai, Manli; Kurihara, Hiroshi; Lee, Kenneth Ka Ho; Yang, Xuesong

2014-01-01

Caffeine has been an integral component of our diet and medicines for centuries. It is now known that over consumption of caffeine has detrimental effects on our health, and also disrupts normal foetal development in pregnant mothers. In this study, we investigated the potential teratogenic effect of caffeine over-exposure on eye development in the early chick embryo. Firstly, we demonstrated that caffeine exposure caused chick embryos to develop asymmetrical microphthalmia and induced the orbital bone to develop abnormally. Secondly, caffeine exposure perturbed Pax6 expression in the retina of the developing eye. In addition, it perturbed the migration of HNK-1+ cranial neural crest cells. Pax6 is an important gene that regulates eye development, so altering the expression of this gene might be the cause for the abnormal eye development. Thirdly, we found that reactive oxygen species (ROS) production was significantly increased in eye tissues following caffeine treatment, and that the addition of anti-oxidant vitamin C could rescue the eyes from developing abnormally in the presence of caffeine. This suggests that excess ROS induced by caffeine is one of the mechanisms involved in the teratogenic alterations observed in the eye during embryogenesis. In sum, our experiments in the chick embryo demonstrated that caffeine is a potential teratogen. It causes asymmetrical microphthalmia to develop by increasing ROS production and perturbs Pax6 expression. PMID:24636305

Somatic embryogenesis of East Kalimantan local upland rice varieties

NASA Astrophysics Data System (ADS)

Nurhasanah; Ramitha; Supriyanto, B.; Sunaryo, W.

2018-04-01

Somatic embryogenesis is the formation, growth and development of embryos from somatic cells. Somatic embryo induction is one of the in vitro plant propagation techniques that is very important for plant developmental purposes. Four local upland rice varieties of East Kalimantan, Mayas Pancing, Gedagai, Siam and Serai, were used in this study. A total of 200 explants (mature rice grains) for each varieties were inoculated on MS solid medium supplemented with 1 mg L-1 2,4 Dichlorophenoxy acetic acid (2,4-D) and 0.5 mg L-1 6-Benzylaminopurine (BAP). The results showed that response of each variety differed to embryosomatic induction, indicated by callus induction rate and callus quality, in terms of callus color and structure. The fastest callus formation was sobserved in Gedagai variety (8 days) while Mayas Pancing (13 days) was the latest one. The rate of callus induction varied from 60 to 98.5 %, and Serai variety has the highest callus induction rate. The highest friable callus structure was found in Siam variety (89.1%) and the lowest was in Gedagai (62.5%). Callus color was dominated by the yellowish-white (transparent) on all varieties tested. Most of the callus was potential as embryogenic callus characterized from the nodular and globular of friable callus structure and its yellowish-white color.

The Identification and Assessment of Late-life ADHD in Memory Clinics

PubMed Central

Fischer, Barbara L.; Gunter-Hunt, Gail; Steinhafel, Courtney Holm; Howell, Timothy

2013-01-01

INTRODUCTION Little data exists about attention deficit hyperactivity disorder (ADHD) in late life. While evaluating patients’ memory problems, our Memory Clinic staff has periodically identified ADHD in previously undiagnosed adults. We conducted a survey to assess the extent to which other memory clinics view ADHD as a relevant clinical issue. METHOD We developed and sent a questionnaire to Memory Clinics in the United States to ascertain how ADHD was identified and addressed. The percentage of responding memory clinics’ means of assessing and managing late-life ADHD comprised the measurements for this study. RESULTS Approximately one-half of responding memory clinics reported seeing ADHD patients. Of these, one-half reported identifying previously diagnosed cases, and almost one-half reported diagnosing ADHD themselves. One fifth of clinics reported screening regularly for ADHD, and few clinics described treatment methods. CONCLUSION Our results suggest that U.S. memory clinics may not adequately identify and address ADHD in late life. PMID:22173147

A regulatory network-based approach dissects late maturation processes related to the acquisition of desiccation tolerance and longevity of Medicago truncatula seeds.

PubMed

Verdier, Jerome; Lalanne, David; Pelletier, Sandra; Torres-Jerez, Ivone; Righetti, Karima; Bandyopadhyay, Kaustav; Leprince, Olivier; Chatelain, Emilie; Vu, Benoit Ly; Gouzy, Jerome; Gamas, Pascal; Udvardi, Michael K; Buitink, Julia

2013-10-01

In seeds, desiccation tolerance (DT) and the ability to survive the dry state for prolonged periods of time (longevity) are two essential traits for seed quality that are consecutively acquired during maturation. Using transcriptomic and metabolomic profiling together with a conditional-dependent network of global transcription interactions, we dissected the maturation events from the end of seed filling to final maturation drying during the last 3 weeks of seed development in Medicago truncatula. The network revealed distinct coexpression modules related to the acquisition of DT, longevity, and pod abscission. The acquisition of DT and dormancy module was associated with abiotic stress response genes, including late embryogenesis abundant (LEA) genes. The longevity module was enriched in genes involved in RNA processing and translation. Concomitantly, LEA polypeptides accumulated, displaying an 18-d delayed accumulation compared with transcripts. During maturation, gulose and stachyose levels increased and correlated with longevity. A seed-specific network identified known and putative transcriptional regulators of DT, including ABSCISIC ACID-INSENSITIVE3 (MtABI3), MtABI4, MtABI5, and APETALA2/ ETHYLENE RESPONSE ELEMENT BINDING PROTEIN (AtAP2/EREBP) transcription factor as major hubs. These transcriptional activators were highly connected to LEA genes. Longevity genes were highly connected to two MtAP2/EREBP and two basic leucine zipper transcription factors. A heat shock factor was found at the transition of DT and longevity modules, connecting to both gene sets. Gain- and loss-of-function approaches of MtABI3 confirmed 80% of its predicted targets, thereby experimentally validating the network. This study captures the coordinated regulation of seed maturation and identifies distinct regulatory networks underlying the preparation for the dry and quiescent states.

WAVE2 deficiency reveals distinct roles in embryogenesis and Rac-mediated actin-based motility.

PubMed

Yan, Catherine; Martinez-Quiles, Narcisa; Eden, Sharon; Shibata, Tomoyuki; Takeshima, Fuminao; Shinkura, Reiko; Fujiwara, Yuko; Bronson, Roderick; Snapper, Scott B; Kirschner, Marc W; Geha, Raif; Rosen, Fred S; Alt, Frederick W

2003-07-15

The Wiskott-Aldrich syndrome related protein WAVE2 is implicated in the regulation of actin-cytoskeletal reorganization downstream of the small Rho GTPase, Rac. We inactivated the WAVE2 gene by gene-targeted mutation to examine its role in murine development and in actin assembly. WAVE2-deficient embryos survived until approximately embryonic day 12.5 and displayed growth retardation and certain morphological defects, including malformations of the ventricles in the developing brain. WAVE2-deficient embryonic stem cells displayed normal proliferation, whereas WAVE2-deficient embryonic fibroblasts exhibited severe growth defects, as well as defective cell motility in response to PDGF, lamellipodium formation and Rac-mediated actin polymerization. These results imply a non-redundant role for WAVE2 in murine embryogenesis and a critical role for WAVE2 in actin-based processes downstream of Rac that are essential for cell movement.

Untwisting the Caenorhabditis elegans embryo.

PubMed

Christensen, Ryan Patrick; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina-Solis, Javier; Guo, Min; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter W; Tashakkori, Nicole; McCreedy, Evan; Liu, Huafeng; McAuliffe, Matthew; Mohler, William; Colón-Ramos, Daniel A; Bao, Zhirong; Shroff, Hari

2015-12-03

The nematode Caenorhabditis elegans possesses a simple embryonic nervous system with few enough neurons that the growth of each cell could be followed to provide a systems-level view of development. However, studies of single cell development have largely been conducted in fixed or pre-twitching live embryos, because of technical difficulties associated with embryo movement in late embryogenesis. We present open-source untwisting and annotation software (http://mipav.cit.nih.gov/plugin_jws/mipav_worm_plugin.php) that allows the investigation of neurodevelopmental events in late embryogenesis and apply it to track the 3D positions of seam cell nuclei, neurons, and neurites in multiple elongating embryos. We also provide a tutorial describing how to use the software (Supplementary file 1) and a detailed description of the untwisting algorithm (Appendix). The detailed positional information we obtained enabled us to develop a composite model showing movement of these cells and neurites in an 'average' worm embryo. The untwisting and cell tracking capabilities of our method provide a foundation on which to catalog C. elegans neurodevelopment, allowing interrogation of developmental events in previously inaccessible periods of embryogenesis.

Untwisting the Caenorhabditis elegans embryo

PubMed Central

Christensen, Ryan Patrick; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina-Solis, Javier; Guo, Min; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter W; Tashakkori, Nicole; McCreedy, Evan; Liu, Huafeng; McAuliffe, Matthew; Mohler, William; Colón-Ramos, Daniel A; Bao, Zhirong; Shroff, Hari

2015-01-01

The nematode Caenorhabditis elegans possesses a simple embryonic nervous system with few enough neurons that the growth of each cell could be followed to provide a systems-level view of development. However, studies of single cell development have largely been conducted in fixed or pre-twitching live embryos, because of technical difficulties associated with embryo movement in late embryogenesis. We present open-source untwisting and annotation software (http://mipav.cit.nih.gov/plugin_jws/mipav_worm_plugin.php) that allows the investigation of neurodevelopmental events in late embryogenesis and apply it to track the 3D positions of seam cell nuclei, neurons, and neurites in multiple elongating embryos. We also provide a tutorial describing how to use the software (Supplementary file 1) and a detailed description of the untwisting algorithm (Appendix). The detailed positional information we obtained enabled us to develop a composite model showing movement of these cells and neurites in an 'average' worm embryo. The untwisting and cell tracking capabilities of our method provide a foundation on which to catalog C. elegans neurodevelopment, allowing interrogation of developmental events in previously inaccessible periods of embryogenesis. DOI: http://dx.doi.org/10.7554/eLife.10070.001 PMID:26633880

A genetic screen for temperature-sensitive cell-division mutants of Caenorhabditis elegans.

PubMed Central

O'Connell, K F; Leys, C M; White, J G

1998-01-01

A novel screen to isolate conditional cell-division mutants in Caenorhabditis elegans has been developed. The screen is based on the phenotypes associated with existing cell-division mutations: some disrupt postembryonic divisions and affect formation of the gonad and ventral nerve cord-resulting in sterile, uncoordinated animals-while others affect embryonic divisions and result in lethality. We obtained 19 conditional mutants that displayed these phenotypes when shifted to the restrictive temperature at the appropriate developmental stage. Eighteen of these mutations have been mapped; 17 proved to be single alleles of newly identified genes, while 1 proved to be an allele of a previously identified gene. Genetic tests on the embryonic lethal phenotypes indicated that for 13 genes, embryogenesis required maternal expression, while for 6, zygotic expression could suffice. In all cases, maternal expression of wild-type activity was found to be largely sufficient for embryogenesis. Cytological analysis revealed that 10 mutants possessed embryonic cell-division defects, including failure to properly segregate DNA, failure to assemble a mitotic spindle, late cytokinesis defects, prolonged cell cycles, and improperly oriented mitotic spindles. We conclude that this approach can be used to identify mutations that affect various aspects of the cell-division cycle. PMID:9649522

Somatic embryogenesis from seeds in a broad range of Vitis vinifera L. varieties: rescue of true-to-type virus-free plants.

PubMed

San Pedro, Tània; Gammoudi, Najet; Peiró, Rosa; Olmos, Antonio; Gisbert, Carmina

2017-11-29

Somatic embryogenesis is the preferred method for cell to plant regeneration in Vitis vinifera L. However, low frequencies of plant embryo conversion are commonly found. In a previous work we obtained from cut-seeds of a grapevine infected with the Grapevine leafroll associated viruses 1 and 3 (GLRaV-1 and GLRaV-3), high rates of direct regeneration, embryo plant conversion and sanitation. The aim of this study is to evaluate the usefulness of this procedure for regeneration of other grapevine varieties which include some infected with one to three common grapevine viruses (GLRaV-3, Grapevine fanleaf virus (GFLV) and Grapevine fleck virus (GFkV)). As grapevine is highly heterozygous, it was necessary to select from among the virus-free plants those that regenerated from mother tissues around the embryo, (true-to-type). Somatic embryogenesis and plant regeneration were achieved in a first experiment, using cut-seeds from the 14 grapevine varieties Airén, Cabernet Franc, Cabernet Sauvignon, Mencía, Merlot, Monastrell, Petit Verdot, Pinot Blanc (infected by GFLV and GFkV), Pinot Gris, Pinot Meunier, Pinot Noir, Syrah, Tempranillo (infected by GFLV), and Verdil. All regenerated plants were confirmed to be free of GFkV whereas at least 68% sanitation was obtained for GFLV. The SSR profiles of the virus-free plants showed, in both varieties, around 10% regeneration from mother tissue (the same genetic make-up as the mother plant). In a second experiment, this procedure was used to sanitize the varieties Cabernet Franc, Godello, Merlot and Valencí Blanc infected by GLRaV-3, GFkV and/or GFLV. Cut-seeds can be used as explants for embryogenesis induction and plant conversion in a broad range of grapevine varieties. The high regeneration rates obtained with this procedure facilitate the posterior selection of true-to-type virus-free plants. A sanitation rate of 100% was obtained for GFkV as this virus is not seed-transmitted. However, the presence of GLRaV-3 and GFLV in

Experimental study of the embryogenesis of gastrointestinal duplication and enteric cyst.

PubMed

Emura, Takaki; Hashizume, Kohei; Asashima, Makoto

2003-05-01

The theory of gastrointestinal duplication and enteric cyst embryogenesis was verified by examining the developmental process of this experimentally induced anomaly. In Cynopus pyrrhogaster (amphibian) embryos (stage 18), the dorsal midline structures (including the neural plate and notochord) were split regionally to induce partial separation of the notochord and gut anlage endoderm herniation between the split elements of the notochord. Following this procedure, the embryonic development was traced morphologically and histologically. Control embryos were cultured without the procedure. Following the incubation and breeding period, gastrointestinal duplication and enteric cysts were observed with vertebral anomaly, spina bifida, split cord malformation and subcutaneous manifestations in the mature animals. The combination of anomalies that was observed in these experimental animals is consistent with that found in "split notochord syndrome." No abnormal morphology or histology was observed in the control group. The embryogenetic theory of gastrointestinal duplication and enteric cysts was thus verified by simulating the partial separation of the notochord, which induced split notochord syndrome in laboratory animals. The results indicate that gastrointestinal duplication and enteric cysts may arise through a process of herniation of the gut anlage endoderm between split elements of the notochord.

The Xenopus Tgfbi is required for embryogenesis through regulation of canonical Wnt signalling.

PubMed

Wang, Feng; Hu, Wanzhou; Xian, Jian; Ohnuma, Shin-ichi; Brenton, James D

2013-07-01

Tgfbi, a fasciclin family extracellular matrix protein, has various roles in human diseases from corneal dystrophies to cancer. However, the molecular mechanisms that underlie its functions are poorly understood. Here, we studied the role of Tgfbi during Xenopus embryogenesis. During gastrulation and immediately after, Xtgfbi is expressed at developmentally important signaling centers including the dorsal marginal zone, notochord and floorplate. Xtgfbi knockdown by anti-sense morpholinos causes defective organizer induction, patterning and differentiation of muscle, neuron and neural crests, similar to suppression of canonical Wnt signaling. In Xenopus embryos and animal caps as well as DLD-1 cells, we show that Tgfbi is strongly required for the full activation of the canonical Wnt pathway by promoting phosphorylation of GSK3β and consequently enhancing the stabilization and nuclear localization of β-catenin. Further analysis shows that Tgfbi is likely to promote GSK3β phosphorylation through integrin-linked kinase. Copyright © 2013 Elsevier Inc. 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.

2D CFT partition functions at late times

NASA Astrophysics Data System (ADS)

Dyer, Ethan; Gur-Ari, Guy

2017-08-01

We consider the late time behavior of the analytically continued partition function Z( β + it) Z( β - it) in holographic 2 d CFTs. This is a probe of information loss in such theories and in their holographic duals. We show that each Virasoro character decays in time, and so information is not restored at the level of individual characters. We identify a universal decaying contribution at late times, and conjecture that it describes the behavior of generic chaotic 2 d CFTs out to times that are exponentially large in the central charge. It was recently suggested that at sufficiently late times one expects a crossover to random matrix behavior. We estimate an upper bound on the crossover time, which suggests that the decay is followed by a parametrically long period of late time growth. Finally, we discuss gravitationally-motivated integrable theories and show how information is restored at late times by a series of characters. This hints at a possible bulk mechanism, where information is restored by an infinite sum over non-perturbative saddles.

Impact of Urban Neighborhood Disadvantage on Late Stage Breast Cancer Diagnosis in Virginia.

PubMed

DeGuzman, Pam Baker; Cohn, Wendy F; Camacho, Fabian; Edwards, Brandy L; Sturz, Vanessa N; Schroen, Anneke T

2017-04-01

Research suggests that residents of inner-city urban neighborhoods have higher rates of late stage cancer diagnosis. Identifying urban neighborhoods with high rates of both concentrated disadvantage and late stage cancer diagnosis may assist health care providers to target screening interventions to reduce disparities. The purposes of this study were to (1) create an index to evaluate concentrated disadvantage (CD) using non-racial measures of poverty, (2) determine the impact of neighborhood CD on late stage breast cancer diagnosis in US cities, and (3) to understand the role of obesity on this relationship. We used census block group- (CBG) level poverty indicators from five Virginia cities to develop the index. Breast cancer cases of women aged 18-65 who lived in the five cities were identified from the 2000-2012 Virginia Cancer Registry. A logistic regression model with random intercept was used to evaluate the impact of disadvantage on late stage breast cancer diagnosis. CBG-level maps were developed to geographically identify neighborhoods with both high rates of CD and late breast cancer staging. Over 900 CBGs and 6000 breast cases were included. Global fit of the concentrated disadvantage model was acceptable. The effect of disadvantage on late stage was significant (OR = 1.0083, p = 0.032). Inner-city poverty impacts risk of late stage breast cancer diagnosis. Area-level obesity is highly correlated with neighborhood poverty (ρ = 0.74, p < 0.0001) but the mediating direct and indirect effects are non-significant. Intervening in these high poverty neighborhoods may help combat disparities in late stage diagnosis for urban poor and for minorities living in these underserved neighborhoods, but more study is needed to understanding the complex relationship between concentrated neighborhood poverty, obesity, and late stage diagnosis.

The significance of PIWI family expression in human lung embryogenesis and non-small cell lung cancer

PubMed Central

Navarro, Alfons; Tejero, Rut; Viñolas, Nuria; Cordeiro, Anna; Marrades, Ramon M.; Fuster, Dolors; Caritg, Oriol; Moises, Jorge; Muñoz, Carmen; Molins, Laureano; Ramirez, Josep; Monzo, Mariano

2015-01-01

The expression of Piwi-interacting RNAs, small RNAs that bind to PIWI proteins, was until recently believed to be limited to germinal stem cells. We have studied the expression of PIWI genes during human lung embryogenesis and in paired tumor and normal tissue prospectively collected from 71 resected non-small-cell lung cancer patients. The mRNA expression analysis showed that PIWIL1 was highly expressed in 7-week embryos and downregulated during the subsequent weeks of development. PIWIL1 was expressed in 11 of the tumor samples but in none of the normal tissue samples. These results were validated by immunohistochemistry, showing faint cytoplasmic reactivity in the PIWIL1-positive samples. Interestingly, the patients expressing PIWIL1 had a shorter time to relapse (TTR) (p = 0.006) and overall survival (OS) (p = 0.0076) than those without PIWIL1 expression. PIWIL2 and 4 were downregulated in tumor tissue in comparison to the normal tissue (p < 0.001) and the patients with lower levels of PIWIL4 had shorter TTR (p = 0.048) and OS (p = 0.033). In the multivariate analysis, PIWIL1 expression emerged as an independent prognostic marker. Using 5-Aza-dC treatment and bisulfite sequencing, we observed that PIWIL1 expression could be regulated in part by methylation. Finally, an in silico study identified a stem-cell expression signature associated with PIWIL1 expression. PMID:25742785

Spatial Anisotropies and Temporal Fluctuations in Extracellular Matrix Network Texture during Early Embryogenesis

PubMed Central

Loganathan, Rajprasad; Potetz, Brian R.; Rongish, Brenda J.; Little, Charles D.

2012-01-01

Early stages of vertebrate embryogenesis are characterized by a remarkable series of shape changes. The resulting morphological complexity is driven by molecular, cellular, and tissue-scale biophysical alterations. Operating at the cellular level, extracellular matrix (ECM) networks facilitate cell motility. At the tissue level, ECM networks provide material properties required to accommodate the large-scale deformations and forces that shape amniote embryos. In other words, the primordial biomaterial from which reptilian, avian, and mammalian embryos are molded is a dynamic composite comprised of cells and ECM. Despite its central importance during early morphogenesis we know little about the intrinsic micrometer-scale surface properties of primordial ECM networks. Here we computed, using avian embryos, five textural properties of fluorescently tagged ECM networks — (a) inertia, (b) correlation, (c) uniformity, (d) homogeneity, and (e) entropy. We analyzed fibronectin and fibrillin-2 as examples of fibrous ECM constituents. Our quantitative data demonstrated differences in the surface texture between the fibronectin and fibrillin-2 network in Day 1 (gastrulating) embryos, with the fibronectin network being relatively coarse compared to the fibrillin-2 network. Stage-specific regional anisotropy in fibronectin texture was also discovered. Relatively smooth fibronectin texture was exhibited in medial regions adjoining the primitive streak (PS) compared with the fibronectin network investing the lateral plate mesoderm (LPM), at embryonic stage 5. However, the texture differences had changed by embryonic stage 6, with the LPM fibronectin network exhibiting a relatively smooth texture compared with the medial PS-oriented network. Our data identify, and partially characterize, stage-specific regional anisotropy of fibronectin texture within tissues of a warm-blooded embryo. The data suggest that changes in ECM textural properties reflect orderly time

Late Talkers: A Population-Based Study of Risk Factors and School Readiness Consequences

ERIC Educational Resources Information Center

Hammer, Carol Scheffner; Morgan, Paul; Farkas, George; Hillemeier, Marianne; Bitetti, Dana; Maczuga, Steve

2017-01-01

Purpose: This study was designed to (a) identify sociodemographic, pregnancy and birth, family health, and parenting and child care risk factors for being a late talker at 24 months of age; (b) determine whether late talkers continue to have low vocabulary at 48 months; and (c) investigate whether being a late talker plays a unique role in…

QTL-seq approach identified genomic regions and diagnostic markers for rust and late leaf spot resistance in groundnut (Arachis hypogaea L.).

PubMed

Pandey, Manish K; Khan, Aamir W; Singh, Vikas K; Vishwakarma, Manish K; Shasidhar, Yaduru; Kumar, Vinay; Garg, Vanika; Bhat, Ramesh S; Chitikineni, Annapurna; Janila, Pasupuleti; Guo, Baozhu; Varshney, Rajeev K

2017-08-01

Rust and late leaf spot (LLS) are the two major foliar fungal diseases in groundnut, and their co-occurrence leads to significant yield loss in addition to the deterioration of fodder quality. To identify candidate genomic regions controlling resistance to rust and LLS, whole-genome resequencing (WGRS)-based approach referred as 'QTL-seq' was deployed. A total of 231.67 Gb raw and 192.10 Gb of clean sequence data were generated through WGRS of resistant parent and the resistant and susceptible bulks for rust and LLS. Sequence analysis of bulks for rust and LLS with reference-guided resistant parent assembly identified 3136 single-nucleotide polymorphisms (SNPs) for rust and 66 SNPs for LLS with the read depth of ≥7 in the identified genomic region on pseudomolecule A03. Detailed analysis identified 30 nonsynonymous SNPs affecting 25 candidate genes for rust resistance, while 14 intronic and three synonymous SNPs affecting nine candidate genes for LLS resistance. Subsequently, allele-specific diagnostic markers were identified for three SNPs for rust resistance and one SNP for LLS resistance. Genotyping of one RIL population (TAG 24 × GPBD 4) with these four diagnostic markers revealed higher phenotypic variation for these two diseases. These results suggest usefulness of QTL-seq approach in precise and rapid identification of candidate genomic regions and development of diagnostic markers for breeding applications. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

WAVE2 deficiency reveals distinct roles in embryogenesis and Rac-mediated actin-based motility

PubMed Central

Yan, Catherine; Martinez-Quiles, Narcisa; Eden, Sharon; Shibata, Tomoyuki; Takeshima, Fuminao; Shinkura, Reiko; Fujiwara, Yuko; Bronson, Roderick; Snapper, Scott B.; Kirschner, Marc W.; Geha, Raif; Rosen, Fred S.; Alt, Frederick W.

2003-01-01

The Wiskott–Aldrich syndrome related protein WAVE2 is implicated in the regulation of actin-cytoskeletal reorganization downstream of the small Rho GTPase, Rac. We inactivated the WAVE2 gene by gene-targeted mutation to examine its role in murine development and in actin assembly. WAVE2-deficient embryos survived until approximately embryonic day 12.5 and displayed growth retardation and certain morphological defects, including malformations of the ventricles in the developing brain. WAVE2-deficient embryonic stem cells displayed normal proliferation, whereas WAVE2-deficient embryonic fibroblasts exhibited severe growth defects, as well as defective cell motility in response to PDGF, lamellipodium formation and Rac-mediated actin polymerization. These results imply a non-redundant role for WAVE2 in murine embryogenesis and a critical role for WAVE2 in actin-based processes downstream of Rac that are essential for cell movement. PMID:12853475

Paradoxical physiological transitions from aging to late life in Drosophila.

PubMed

Shahrestani, Parvin; Quach, Julie; Mueller, Laurence D; Rose, Michael R

2012-02-01

In a variety of organisms, adulthood is divided into aging and late life, where aging is a period of exponentially increasing mortality rates and late life is a period of roughly plateaued mortality rates. In this study we used ∼57,600 Drosophila melanogaster from six replicate populations to examine the physiological transitions from aging to late life in four functional characters that decline during aging: desiccation resistance, starvation resistance, time spent in motion, and negative geotaxis. Time spent in motion and desiccation resistance declined less quickly in late life compared to their patterns of decline during aging. Negative geotaxis declined at a faster rate in late life compared to its rate of decline during aging. These results yield two key findings: (1) Late-life physiology is distinct from the physiology of aging, in that there is not simply a continuation of the physiological trends which characterize aging; and (2) late life physiology is complex, in that physiological characters vary with respect to their stabilization, deceleration, or acceleration in the transition from aging to late life. These findings imply that a correct understanding of adulthood requires identifying and appropriately characterizing physiology during properly delimited late-life periods as well as aging periods.

Paradoxical Physiological Transitions from Aging to Late Life in Drosophila

PubMed Central

Quach, Julie; Mueller, Laurence D.; Rose, Michael R.

2012-01-01

Abstract In a variety of organisms, adulthood is divided into aging and late life, where aging is a period of exponentially increasing mortality rates and late life is a period of roughly plateaued mortality rates. In this study we used ∼57,600 Drosophila melanogaster from six replicate populations to examine the physiological transitions from aging to late life in four functional characters that decline during aging: desiccation resistance, starvation resistance, time spent in motion, and negative geotaxis. Time spent in motion and desiccation resistance declined less quickly in late life compared to their patterns of decline during aging. Negative geotaxis declined at a faster rate in late life compared to its rate of decline during aging. These results yield two key findings: (1) Late-life physiology is distinct from the physiology of aging, in that there is not simply a continuation of the physiological trends which characterize aging; and (2) late life physiology is complex, in that physiological characters vary with respect to their stabilization, deceleration, or acceleration in the transition from aging to late life. These findings imply that a correct understanding of adulthood requires identifying and appropriately characterizing physiology during properly delimited late-life periods as well as aging periods. PMID:22233126

An Empirical Typology of Narcissism and Mental Health in Late Adolescence

ERIC Educational Resources Information Center

Lapsley, Daniel K.; Aalsma, Matthew C.

2006-01-01

A two-step cluster analytic strategy was used in two studies to identify an empirically derived typology of narcissism in late adolescence. In Study 1, late adolescents (N=204) responded to the profile of narcissistic dispositions and measures of grandiosity (''superiority'') and idealization (''goal instability'') inspired by Kohut's theory,…

Embryogenesis, hatching and larval development of Artemia during orbital spaceflight

NASA Astrophysics Data System (ADS)

Spooner, B. S.; Debell, L.; Armbrust, L.; Guikema, J. A.; Metcalf, J.; Paulsen, A.

1994-08-01

Developmental biology studies, using gastrula-arrested cysts of the brine shrimp Artemia franciscana, were conducted during two flights of the space shuttle Atlantis (missions STS-37 and STS-43) in 1991. Dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. Development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fixative. Comparison of space results with simultaneous ground control experiments showed that equivalent percentages of naupliar larvae hatched in the syringes (40%). Thus, reactivation of development, completion of embryogenesis, emergence and hatching took place, during spaceflight, without recognizable alteration in numbers of larvae produced. Post-hatching larval development was studied in experiments where development was terminated, by intrduction of fixative, 2 days, 4 days, and 8 days after reinitiation of development. During spaceflight, successive larval instars or stages, interrupted by molts, occurred, generating brine shrimp at appropriate larval instars. Naupliar larvae possessed the single naupliar eye, and development of the lateral pair of adult eyes also took place in space. Transmission electron microscopy revealed extensive differentiation, including skeletal muscle and gut endoderm, as well as the eye tissues. These studies demonstrate the potential value of Artemia for developmental biology studies during spaceflight, and show that extensive degress of development can take place in this microgravity environment.

The effects of microgravity on gametogenesis, fertilization, and early embryogenesis

NASA Astrophysics Data System (ADS)

Tan, X.

Gametogenesis fertilization and early embryogenesis are crucial periods for normal development afterwards In past three decades many experiments have been conducted in space and in simulated weightlessness induced by clinostats to elucidate the issue Different animal species including Drosophila wasp shrimp fish amphibian mouse rats etc have been used for the study Oogenesis and spermatogenesis are affected by microgravity in different ways Some researches found that microgravity condition perturbed the process of oogenesis in many species A significant increased frequency of chromosomal non-disjunction was found in Drosophila females resulting the loss of chromosomes during meiosis and inhibition of cell division Studies on wasp showed a decreased hatchability and accumulation of unhatched eggs when the insects were exposed to spaceflight at different stages of oogenesis For experiments conducted on vertebrate animal models the results are somehow different however Microgravity has no significant effect for fish Medaka etc amphibian South African clawed toad Xenopus laevis or mammals mouse Spermatogenesis on the other hand is more significantly affected by microgravity condition Some researches indicated sperm are sensitive to changes in gravitational force and this sensitivity affects the ability of sperm to fertilize eggs Sperm swim with higher velocity in microgravity which is coupled with altered protein phosphorylation level in sperm under microgravity condition Microgravity also induced activation of the

Gene-specific of endocannabinoid receptor 1 (cnr1a) by ethanol probably leads to the development of fetal alcohol spectrum disorder (FASD) phenotypes in Japanese rice fish (Oryzias latipes) embryogenesis

USDA-ARS?s Scientific Manuscript database

Developmental ethanol exposure is able to induce Fetal Alcohol Spectrum Disorder (FASD) phenotypes in Japanese rice fish (Oryzias latipes). This study investigated possible differential expression of cannabinoid receptor (cnr) mRNAs during Japanese rice fish embryogenesis and variability to ethanol-...

Molecular aspects of zygotic embryogenesis in sunflower (Helianthus annuus L.): correlation of positive histone marks with HaWUS expression and putative link HaWUS/HaL1L.

PubMed

Salvini, Mariangela; Fambrini, Marco; Giorgetti, Lucia; Pugliesi, Claudio

2016-01-01

The link HaWUS/ HaL1L , the opposite transcriptional behavior, and the decrease/increase in positive histone marks bond to both genes suggest an inhibitory effect of WUS on HaL1L in sunflower zygotic embryos. In Arabidopsis, a group of transcription factors implicated in the earliest events of embryogenesis is the WUSCHEL-RELATED HOMEOBOX (WOX) protein family including WUSCHEL (WUS) and other 14 WOX protein, some of which contain a conserved WUS-box domain in addition to the homeodomain. WUS transcripts appear very early in embryogenesis, at the 16-cell embryo stage, but gradually become restricted to the center of the developing shoot apical meristem (SAM) primordium and continues to be expressed in cells of the niche/organizing center of SAM and floral meristems to maintain stem cell population. Moreover, WUS has decisive roles in the embryonic program presumably promoting the vegetative-to-embryonic transition and/or maintaining the identity of the embryonic stem cells. However, data on the direct interaction between WUS and key genes for seed development (as LEC1 and L1L) are not collected. The novelty of this report consists in the characterization of Helianthus annuus WUS (HaWUS) gene and in its analysis regarding the pattern of the methylated lysine 4 (K4) of the Histone H3 and of the acetylated histone H3 during the zygotic embryo development. Also, a parallel investigation was performed for HaL1L gene since two copies of the WUS-binding site (WUSATA), previously identified on HaL1L nucleotide sequence, were able to be bound by the HaWUS recombinant protein suggesting a not described effect of HaWUS on HaL1L transcription.

Late-onset Rasmussen Encephalitis: A literature appraisal.

PubMed

Dupont, Sophie; Gales, Ana; Sammey, Serge; Vidailhet, Marie; Lambrecq, Virginie

2017-08-01

Rasmussen Encephalitis (RE) is classically described as a childhood encephalopathy due to a unilateral inflammation of the cerebral cortex with a presumed immune-mediated pathophysiological basis. Unusual variant forms, including adolescent and adult-onset RE have been described but there is still a doubt whether these atypical cases correspond to classical RE patients. To review evidence, a systematic PubMed search was conducted to retrieve papers addressing late onset RE to assess (i) the positivity rate of classical childhood-onset diagnostic criteria for RE in late-onset RE, (ii) the specific clinical and radiological features that could help earlier diagnosis and therapeutic interventions, (iii) the arguments for an autoimmune pathophysiology including (iiia) the association with autoimmune markers or diseases and (iiib) the effects of immunomodulatory or immunosuppressive treatments. A total of 50 papers were considered. We identified 102 late-onset RE patients with a sex ratio of 8 women for 2 men. 67% fulfilled the consensus diagnostic criteria for RE. As compared to classical RE, the late-onset RE patients exhibited: i) more frequent focal complex partial seizures, ii) less frequent epilepsia partialis continua throughout evolution, iii) a slower evolution with a delayed occurrence of cortical deficit, iv) less cognitive deterioration and v) a better outcome. A specific association with autoimmune markers or diseases was not found. Immunomodulatory therapies, even performed in a late stage, improved late-onset RE patients in 61% of cases. This review proves that late-onset RE is a reality with specific clinical and radiological features. The good response to immunomodulatory treatments brings further arguments for an immune-regulated process. Copyright © 2017 Elsevier B.V. All rights reserved.

Systems biology approach to late-onset Alzheimer's disease genome-wide association study identifies novel candidate genes validated using brain expression data and Caenorhabditis elegans experiments.

PubMed

Mukherjee, Shubhabrata; Russell, Joshua C; Carr, Daniel T; Burgess, Jeremy D; Allen, Mariet; Serie, Daniel J; Boehme, Kevin L; Kauwe, John S K; Naj, Adam C; Fardo, David W; Dickson, Dennis W; Montine, Thomas J; Ertekin-Taner, Nilufer; Kaeberlein, Matt R; Crane, Paul K

2017-10-01

We sought to determine whether a systems biology approach may identify novel late-onset Alzheimer's disease (LOAD) loci. We performed gene-wide association analyses and integrated results with human protein-protein interaction data using network analyses. We performed functional validation on novel genes using a transgenic Caenorhabditis elegans Aβ proteotoxicity model and evaluated novel genes using brain expression data from people with LOAD and other neurodegenerative conditions. We identified 13 novel candidate LOAD genes outside chromosome 19. Of those, RNA interference knockdowns of the C. elegans orthologs of UBC, NDUFS3, EGR1, and ATP5H were associated with Aβ toxicity, and NDUFS3, SLC25A11, ATP5H, and APP were differentially expressed in the temporal cortex. Network analyses identified novel LOAD candidate genes. We demonstrated a functional role for four of these in a C. elegans model and found enrichment of differentially expressed genes in the temporal cortex. Copyright © 2017 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Epidermal patterning genes are active during embryogenesis in Arabidopsis.

PubMed

Costa, Silvia; Dolan, Liam

2003-07-01

Epidermal cells in the root of Arabidopsis seedling differentiate either as hair or non-hair cells, while in the hypocotyl they become either stomatal or elongated cells. WEREWOLF (WER) and GLABRA2 (GL2) are positive regulators of non-hair and elongated cell development. CAPRICE (CPC) is a positive regulator of hair cell development in the root. We show that WER, GL2 and CPC are expressed and active during the stages of embryogenesis when the pattern of cells in the epidermis of the root-hypocotyl axis forms. GL2 is first expressed in the future epidermis in the heart stage embryo and its expression is progressively restricted to those cells that will acquire a non-hair identity in the transition between torpedo and mature stage. The expression of GL2 at the heart stage requires WER function. WER and CPC are transiently expressed throughout the root epidermal layer in the torpedo stage embryo when the cell-specific pattern of GL2 expression is being established in the epidermis. We also show that WER positively regulates CPC transcription and GL2 negatively regulates WER transcription in the mature embryo. We propose that the restriction of GL2 to the future non-hair cells in the root epidermis can be correlated with the activities of WER and CPC during torpedo stage. In the embryonic hypocotyl we show that WER controls GL2 expression. We also provide evidence indicating that CPC may also regulate GL2 expression in the hypocotyl.

Aspects on gametogenesis, fertilization and embryogenesis of two deep-sea polychaetes from Eastern Atlantic cold seeps

NASA Astrophysics Data System (ADS)

Gaudron, S. M.; Hourdez, S.; Olu, K.

2017-11-01

We investigated two gonochoristic species of annelid polychaetes (one siboglinid and one polynoid) from cold seeps that ranged from 525 m to 3300 m in depth (Guiness, Worm Hole and Regab pockmarks) on the Gabon and Congo continental margins (Gulf of Guinea). Different aspects of gametogenesis (oocyte diameter, presence of ovisac, spermatozoa shape, and fecundity), fertilization (in vitro fertilization experiments: IVF) and embryogenesis (cleavage rate) were studied. The sampled siboglinid was a new species of Lamellibrachia and the second population of this genus in the Eastern Atlantic. Mean oocyte diameter was about 100 μm and fully-grown primary oocytes were stored in an ovisac, as in other studied siboglinids. The presence of a single spermatozoon was noted within an oviduct, indicating a possible internal fertilization. The rate of cell division at 6 °C was one cleavage every 20 h. Embryos developed normally to the blastula stage after 5-d post-fertilization at atmospheric pressure suggesting some pressure tolerance. The second polychaete was the scale-worm Branchipolynoe cf. seepensis that lives in commensalism in the mantle cavity of Bathymodiolus aff. boomerang. Anatomical reproductive features were similar to those described in B. seepensis from hydrothermal vents on Mid-Atlantic Ridge, with lecithotrophic larval development and continuous gametogenesis. We performed the first IVF carried out on gametes for any deep-sea polynoid species. Fertilization and development occurred but a number of abnormalities were observed demonstrating a limitation to embryogenesis at atmospheric pressure. The rate of cell division was three times faster at 8 °C than at 4 °C with a maximum stage of 8-cells reached after 72 h post-fertilization. We surprisingly observed some oocytes from the negative seawater control during IVF experiments cleaved to the 2-cell stage, demonstrating the possible occurrence of internal fertilization prior to IVF experiment or the accidental

Dual mode of embryonic development is highlighted by expression and function of Nasonia pair-rule genes

PubMed Central

Rosenberg, Miriam I; Brent, Ava E; Payre, François; Desplan, Claude

2014-01-01

Embryonic anterior–posterior patterning is well understood in Drosophila, which uses ‘long germ’ embryogenesis, in which all segments are patterned before cellularization. In contrast, most insects use ‘short germ’ embryogenesis, wherein only head and thorax are patterned in a syncytial environment while the remainder of the embryo is generated after cellularization. We use the wasp Nasonia (Nv) to address how the transition from short to long germ embryogenesis occurred. Maternal and gap gene expression in Nasonia suggest long germ embryogenesis. However, the Nasonia pair-rule genes even-skipped, odd-skipped, runt and hairy are all expressed as early blastoderm pair-rule stripes and late-forming posterior stripes. Knockdown of Nv eve, odd or h causes loss of alternate segments at the anterior and complete loss of abdominal segments. We propose that Nasonia uses a mixed mode of segmentation wherein pair-rule genes pattern the embryo in a manner resembling Drosophila at the anterior and ancestral Tribolium at the posterior. DOI: http://dx.doi.org/10.7554/eLife.01440.001 PMID:24599282

A cell-based computational model of early embryogenesis coupling mechanical behaviour and gene regulation

NASA Astrophysics Data System (ADS)

Delile, Julien; Herrmann, Matthieu; Peyriéras, Nadine; Doursat, René

2017-01-01

The study of multicellular development is grounded in two complementary domains: cell biomechanics, which examines how physical forces shape the embryo, and genetic regulation and molecular signalling, which concern how cells determine their states and behaviours. Integrating both sides into a unified framework is crucial to fully understand the self-organized dynamics of morphogenesis. Here we introduce MecaGen, an integrative modelling platform enabling the hypothesis-driven simulation of these dual processes via the coupling between mechanical and chemical variables. Our approach relies upon a minimal `cell behaviour ontology' comprising mesenchymal and epithelial cells and their associated behaviours. MecaGen enables the specification and control of complex collective movements in 3D space through a biologically relevant gene regulatory network and parameter space exploration. Three case studies investigating pattern formation, epithelial differentiation and tissue tectonics in zebrafish early embryogenesis, the latter with quantitative comparison to live imaging data, demonstrate the validity and usefulness of our framework.

Somatic Embryogenesis in Olive (Olea europaea L. subsp. europaea var. sativa and var. sylvestris).

PubMed

Rugini, Eddo; Silvestri, Cristian

2016-01-01

Protocols for olive somatic embryogenesis from zygotic embryos and mature tissues have been described for both Olea europaea sub. europaea var. sativa and var. sylvestris. Immature zygotic embryos (no more than 75 days old), used after fruit collection or stored at 12-14 °C for 2-3 months, are the best responsive explants and very slightly genotype dependent, and one single protocol can be effective for a wide range of genotypes. On the contrary, protocols for mature zygotic embryos and for mature tissue of cultivars are often genotype specific, so that they may require many adjustments according to genotypes. The use of thidiazuron and cefotaxime seems to be an important trigger for induction phase particularly for tissues derived from cultivars. Up to now, however, the application of this technique for large-scale propagation is hampered also by the low rate of embryo germination; it proves nonetheless very useful for genetic improvement.

Late glacial aridity in southern Rocky Mountains

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

Davis, O K; Pitblado, B L

While the slopes of the present-day Colorado Rocky Mountains are characterized by large stands of subalpine and montane conifers, the Rockies of the late glacial looked dramatically different. Specifically, pollen records suggest that during the late glacial, Artemisia and Gramineae predominated throughout the mountains of Colorado. At some point between 11,000 and 10,000 B.P., however, both Artemisia and grasses underwent a dramatic decline, which can be identified in virtually every pollen diagram produced for Colorado mountain sites, including Como Lake (Sangre de Cristo Mountains), Copley Lake and Splains; Gulch (near Crested Butte), Molas Lake (San Juan Mountains), and Redrock Lakemore » (Boulder County). Moreover, the same pattern seems to hold for pollen spectra derived for areas adjacent to Colorado, including at sites in the Chuska Mountains of New Mexico and in eastern Wyoming. The implications of this consistent finding are compelling. The closest modem analogues to the Artemisia- and Gramineae-dominated late-glacial Colorado Rockies are found in the relatively arid northern Great Basin, which suggests that annual precipitation was much lower in the late-glacial southern Rocky Mountains than it was throughout the Holocene.« less

Expression of the Fanconi anemia group A gene (Fanca) during mouse embryogenesis.

PubMed

Abu-Issa, R; Eichele, G; Youssoufian, H

1999-07-15

About 80% of all cases of Fanconi anemia (FA) can be accounted for by complementation groups A and C. To understand the relationship between these groups, we analyzed the expression pattern of the mouse FA group-A gene (Fanca) during embryogenesis and compared it with the known pattern of the group-C gene (Fancc). Northern analysis of RNA from mouse embryos at embryonic days 7, 11, 15, and 17 showed a predominant 4.5 kb band in all stages. By in situ hybridization, Fanca transcripts were found in the whisker follicles, teeth, brain, retina, kidney, liver, and limbs. There was also stage-specific variation in Fanca expression, particularly within the developing whiskers and the brain. Some tissues known to express Fancc (eg, gut) failed to show Fanca expression. These observations show that (1) Fanca is under both tissue- and stage-specific regulation in several tissues; (2) the expression pattern of Fanca is consistent with the phenotype of the human disease; and (3) Fanca expression is not necessarily coupled to that of Fancc. The presence of distinct tissue targets for FA genes suggests that some of the variability in the clinical phenotype can be attributed to the complementation group assignment.

Ecsit is required for Bmp signaling and mesoderm formation during mouse embryogenesis

PubMed Central

Xiao, Changchun; Shim, Jae-hyuck; Klüppel, Michael; Zhang, Samuel Shao-Min; Dong, Chen; Flavell, Richard A.; Fu, Xin-Yuan; Wrana, Jeffrey L.; Hogan, Brigid L.M.; Ghosh, Sankar

2003-01-01

Bone morphogenetic proteins (Bmps) are members of the transforming growth factor β (TGFβ) superfamily that play critical roles during mouse embryogenesis. Signaling by Bmp receptors is mediated mainly by Smad proteins. In this study, we show that a targeted null mutation of Ecsit, encoding a signaling intermediate of the Toll pathway, leads to reduced cell proliferation, altered epiblast patterning, impairment of mesoderm formation, and embryonic lethality at embryonic day 7.5 (E7.5), phenotypes that mimic the Bmp receptor type1a (Bmpr1a) null mutant. In addition, specific Bmp target gene expression is abolished in the absence of Ecsit. Biochemical analysis demonstrates that Ecsit associates constitutively with Smad4 and associates with Smad1 in a Bmp-inducible manner. Together with Smad1 and Smad4, Ecsit binds to the promoter of specific Bmp target genes. Finally, knock-down of Ecsit with Ecsit-specific short hairpin RNA inhibits both Bmp and Toll signaling. Therefore, these results show that Ecsit functions as an essential component in two important signal transduction pathways and establishes a novel role for Ecsit as a cofactor for Smad proteins in the Bmp signaling pathway. PMID:14633973

Late-Glacial to Late-holocene Shifts in Global Precipitation Delta(sup 18)O

NASA Technical Reports Server (NTRS)

Jasechko, S.; Lechler, A.; Pausata, F.S.R.; Fawcett, P.J.; Gleeson, T.; Cendon, D.I.; Galewsky, J.; LeGrande, A. N.; Risi, C.; Sharp, Z. D.;

Very late stent thrombosis and late target lesion revascularization after sirolimus-eluting stent implantation: five-year outcome of the j-Cypher Registry.

PubMed

Kimura, Takeshi; Morimoto, Takeshi; Nakagawa, Yoshihisa; Kawai, Kazuya; Miyazaki, Shunichi; Muramatsu, Toshiya; Shiode, Nobuo; Namura, Masanobu; Sone, Takahito; Oshima, Shigeru; Nishikawa, Hideo; Hiasa, Yoshikazu; Hayashi, Yasuhiko; Nobuyoshi, Masakiyo; Mitudo, Kazuaki

2012-01-31

There is a scarcity of long-term data from large-scale drug-eluting stent registries with a large enough sample to evaluate low-frequency events such as stent thrombosis (ST). Five-year outcomes were evaluated in 12 812 consecutive patients undergoing sirolimus-eluting stent (SES) implantation in the j-Cypher registry. Cumulative incidence of definite ST was low (30 day, 0.3%; 1 year, 0.6%; and 5 years, 1.6%). However, late and very late ST continued to occur without attenuation up to 5 years after sirolimus-eluting stent implantation (0.26%/y). Cumulative incidence of target lesion revascularization within the first year was low (7.3%). However, late target lesion revascularization beyond 1 year also continued to occur without attenuation up to 5 years (2.2%/y). Independent risk factors of ST were completely different according to the timing of ST onset, suggesting the presence of different pathophysiological mechanisms of ST according to the timing of ST onset: acute coronary syndrome and target of proximal left anterior descending coronary artery for early ST; side-branch stenting, diabetes mellitus, and end-stage renal disease with or without hemodialysis for late ST; and current smoking and total stent length >28 mm for very late ST. Independent risk factors of late target lesion revascularization beyond 1 year were generally similar to those risk factors identified for early target lesion revascularization. Late adverse events such as very late ST and late target lesion revascularization are continuous hazards, lasting at least up to 5 years after implantation of the first-generation drug-eluting stents (sirolimus-eluting stents), which should be the targets for developing improved coronary stents.

Somatic embryogenesis and plant regeneration from cell suspension cultures of Cucumis sativus L.

PubMed

Chee, P P; Tricoli, D M

1988-06-01

A procedure for the regeneration of whole cucumber plants (Cucumis sativus L. cv. Poinsett 76) by embryogenesis from cell suspension cultures is described. Embryogenic callus was initiated from the primary leaves of 14-17 day old plants. Suspension cultures of embryogenic cells were grown in liquid Murashige and Skoog basal medium containing 5 uM 2,4,5-trichlorophenoxyacetic acid and 4 uM 6-benzylaminopurine. Suspension cultures were composed of a population of cells that were densely cytoplasmic and potentially embryogenic. Differentiation of embryos was enhanced by washing the suspension culture cells with MS basal medium containing 0.5% activated charcoal and twice with MS basal medium followed by liquid shake cultures in MS basal medium. Sixty to 70 percent of the embryos prewashed with activated charcoal germinated into plantlets with normal morphology. Embryos obtained from suspension cultured cells without prewashing with activated charcoal organized into plantlets with abnormal primary leaves. Morphologically normal plantlets were obtained by excising the shoot tips and transferring them to fresh medium.

Genome-wide data (ChIP-seq) enabled identification of cell wall-related and aquaporin genes as targets of tomato ASR1, a drought stress-responsive transcription factor

USDA-ARS?s Scientific Manuscript database

Here we report efforts to take advantage of previous knowledge on well characterized proteins that extensively accumulate in dehydration, for example those belonging to the LEA (late embryogenesis abundant) superfamily. ASR proteins, a subgroup exclusive to the plant kingdom (albeit absent in Arabid...

Embryogenesis, hatching and larval development of Artemia during orbital spaceflight

NASA Technical Reports Server (NTRS)

Spooner, B. S.; Debell, L.; Armbrust, L.; Guikema, J. A.; Metcalf, J.; Paulsen, A.

1994-01-01

Developmental biology studies, using gastrula-arrested cysts of the brine shrimp Artemia franciscana, were conducted during two flights of the space shuttle Atlantis (missions STS-37 and STS-43) in 1991. Dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. Development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fixative. Comparison of space results with simultaneous ground control experiments showed that equivalent percentages of naupliar larvae hatched in the syringes (40%). Thus, reactivation of development, completion of embryogenesis, emergence and hatching took place, during spaceflight, without recognizable alteration in numbers of larvae produced. Post-hatching larval development was studied in experiments where development was terminated, by introduction of fixative, 2 days, 4 days, and 8 days after reinitiation of development. During spaceflight, successive larval instars or stages, interrupted by molts, occurred, generating brine shrimp at appropriate larval instars. Naupliar larvae possessed the single naupliar eye, and development of the lateral pair of adult eyes also took place in space. Transmission electron microscopy revealed extensive differentiation, including skeletal muscle and gut endoderm, as well as the eye tissues. These studies demonstrate the potential value of Artemia for developmental biology studies during spa ceflight, and show that extensive degrees of development can take place in this microgravity environment.

Compound heterozygous mutations in electron transfer flavoprotein dehydrogenase identified in a young Chinese woman with late-onset glutaric aciduria type II.

PubMed

Xue, Ying; Zhou, Yun; Zhang, Keqin; Li, Ling; Kayoumu, Abudurexiti; Chen, Liye; Wang, Yuhui; Lu, Zhiqiang

2017-09-26

Glutaric aciduria type II (GA II) is an autosomal recessive disorder affecting fatty acid and amino acid metabolism. The late-onset form of GA II disorder is almost exclusively associated with mutations in the electron transfer flavoprotein dehydrogenase (ETFDH) gene. Till now, the clinical features of late-onset GA II vary widely and pose a great challenge for diagnosis. The aim of the current study is to characterize the clinical phenotypes and genetic basis of a late-onset GAII patient. In this study, we described the clinical and biochemical manifestations of a 23-year-old female Chinese patient with late-onset GA II, and performed genomic DNA-based PCR amplifications and sequence analysis of ETFDH gene of the whole pedigree. We also used in-silicon tools to analyze the mutation and evaluated the pathogenicity of the mutation according to the criteria proposed by American College of Medical Genetics and Genomics (ACMG). The muscle biopsy of this patient revealed lipid storage myopathy. Blood biochemical test and urine organic acid analyses were consistent with GA II. Direct sequence analysis of the ETFDH gene (NM_004453) revealed compound heterozygous mutations: c.250G > A (p.A84T) on exon 3 and c.920C > G (p.S307C) on exon 8. Both mutations were classified as "pathogenic" according to ACMG criteria. In conclusion, our study described the phenotype and genotype of a late-onset GA II patient, reiterating the importance of ETFDH gene screening in these patients.

Disease evolution in late-onset and early-onset systemic lupus erythematosus.

PubMed

Aljohani, R; Gladman, D D; Su, J; Urowitz, M B

2017-10-01

Objective The objective of this study was to compare clinical features, disease activity, and outcome in late-onset versus early-onset systemic lupus erythematosus (SLE) over 5 years of follow up Method Patients with SLE since 1970 were followed prospectively according to standard protocol and tracked on a computerized database. Patients entering the cohort within one year of diagnosis constitute the inception cohort. Patients with late-onset (age at diagnosis ≥50) disease were identified and matched 1:2 based on gender and first clinic visit (±5) years with patients with early-onset disease (age at diagnosis 18-40 years). Results A total of 86 patients with late-onset disease (84.9% female, 81.4% Caucasian, mean age at SLE diagnosis ± SD 58.05 ± 7.30) and 169 patients with early-onset disease (86.4% female, 71% Caucasian, mean age at SLE diagnosis ± SD 27.80 ± 5.90) were identified. At enrollment, late-onset SLE patients had a lower total number of American College of Rheumatology (ACR) criteria, with less renal and neurologic manifestations. Mean SLE Disease Activity Index 2000 (SLEDAI-2K) scores were lower in late-onset SLE, especially renal features and anti-dsDNA positivity. Over 5 years, mean SLEDAI-2K scores decreased in both groups, while mean Systemic Lupus International Collaborating Clinics/ACR Damage Index (SDI) scores increased more significantly in the late-onset group; they developed more cardiovascular, renal, and ocular damage, and had higher prevalence of cardiovascular risk factors. Conclusion Although the late-onset SLE group had a milder presentation and less active disease, with the evolution of disease, they developed more organ damage likely as a consequence of cardiovascular risk factors and aging.

Legumains from the hard tick Haemaphysalis longicornis play modulatory roles in blood feeding and gut cellular remodelling and impact on embryogenesis.

PubMed

Alim, M Abdul; Tsuji, Naotoshi; Miyoshi, Takeharu; Islam, M Khyrul; Hatta, Takeshi; Fujisaki, Kozo

2009-01-01

The biology and vectorial capacity of haematophagous ticks are directly related to effective blood feeding and digestion. The midgut-associated proteases in ticks are involved in the blood (Hb) digestion cascade, the molecular mechanisms of which are yet poorly understood. Our previous studies indicated that Haemaphysalis longicornis midgut-specific asparaginyl endopeptidases/legumains, HlLgm and HlLgm2, act in the Hb digestion cascade. Here, we investigated the potential of these enzymes in blood feeding and digestion, midgut remodelling and reproduction of ticks by employing RNA interference (RNAi) techniques. Injection of HlLgm- and HlLgm2 gene-specific double-stranded RNAs into unfed adult female H. longicornis caused gene-specific transcriptional and translational disruptions. RNAi impacted on tick blood feeding leading to death of the feeding ticks, failure of ticks to reach repletion and significant reductions in engorged tick body weight. Histological examination revealed that deletion of legumains resulted in damage to the midgut tissues and disruption of normal cellular remodelling during feeding. Gene knock-down also caused significantly delayed onset of oviposition, reduced number of eggs and, most strikingly, structurally deformed eggs that failed to hatch suggesting imperfect embryogenesis. Synergistic impacts of RNAi were reflected on all parameters evaluated when HlLgm and HlLgm2 were silenced together. These findings suggest that legumains may play modulatory roles in blood feeding and digestion, midgut cellular remodelling and embryogenesis in H. longicornis. Deletion of legumains in H. longicornis would help in controlling the tick population and thereby transmission of diseases to their hosts.

The Effect of Photobiomodulation on the Sea Urchin Paracentrotus lividus (Echinodermata) Using Higher-Fluence on Fertilization, Embryogenesis, and Larval Development: An In Vitro Study.

PubMed

Amaroli, Andrea; Gambardella, Chiara; Ferrando, Sara; Hanna, Reem; Benedicenti, Alberico; Gallus, Lorenzo; Faimali, Marco; Benedicenti, Stefano

2017-03-01

The aim of this study was to investigate the photobiomodulation (PBM) effect of the 808 nm diode laser irradiation on spermatozoa, eggs, fertilized eggs, embryos, and larvae of Paracentrotus lividus, using two different power settings. Studies have shown the possible use of PBM in artificial insemination. These have shown the potential effect of low-power laser irradiation on spermatozoa, while there are few studies on the effect of laser photonic energy on oocytes and almost no reports on the influence of lasers in embryogenesis. P. lividus gametes, zygotes, embryos, and larvae were irradiated using the 808 nm diode laser (fluence 64 J/cm 2 using 1 W or 192 J/cm 2 with 3 W) with a flat-top hand-piece delivery, compared to a control without laser irradiation (0 J/cm 2 -0 W). The fertilization rate and the early developmental stages were investigated. The fertilization ability was not affected by the sperm/egg irradiation. At the gastrula stage, no significant differences were observed compared with the control samples. In the late pluteus stage, there were no differences in the developmental percentage observed between the control and the treated samples (1 W), with the exception of larvae from gastrulae and larvae, which were irradiated at 3 W. This study has demonstrated that both the 64 J/cm 2 -1 W and the 192 J/cm 2 -3 W do not induce morphological damage on the irradiated P. lividus gametes whose zygotes generate normal embryos and larvae. Our data therefore support the assumption to use higher fluence in preliminary studies on in vitro fertilization.

Nanos3 not nanos1 and nanos2 is a germ cell marker gene in large yellow croaker during embryogenesis.

PubMed

Han, Kunhuang; Chen, Shihai; Cai, Mingyi; Jiang, Yonghua; Zhang, Ziping; Wang, Yilei

2018-04-01

In this study, three nanos gene subtypes (Lcnanos1, Lcnanos2 and Lcnanos3) from Larimichthys crocea, were cloned and characterized. We determined the spatio-temporal expression patterns of each subtype in tissues as well as the cellular localization of mRNA in embryos. Results showed that deduced Nanos proteins have two main homology domains: N-terminal CCR4/NOT1 deadenylase interaction domain and highly conserved carboxy-terminal region bearing two conserved CCHC zinc-finger motifs. The expression levels of Lcnanos1 in testis were significantly higher than other tissues, followed by heart, brain, eye, and ovary. Nevertheless, both Lcnanos2 and Lcnanos3 were restrictedly expressed in testis and ovary, respectively. No signals of Lcnanos1 and Lcnanos2 expression were detected at any developmental stages during embryogenesis. On the contrary, the signals of Lcnanos3 were detected in all stages examined. Lcnanos3 transcripts were firstly localized to the distal end of cleavage furrow at the 2-cell stage. Subsequently, mounting positive signals started to appear in a small number of cells as the embryo developed to blastula stage and early-gastrula stage. As development proceeded, positive signals were found in the primitive gonadal ridge. These cells of Lcnanos3 positive signals implied the specification of the future PGCs at this stage. It also suggested that PGCs of croaker originate from four clusters of cells which inherit maternal germ plasm at blastula stage. Furthermore, we preliminarily analyzed the migration route of PGCs in embryos of L. crocea. In short, this study laid the foundation for studies on specification and development of germ cell from L. crocea during embryogenesis. Copyright © 2018 Elsevier Inc. All rights reserved.

The epigenetic memory of temperature during embryogenesis modifies the expression of bud burst-related genes in Norway spruce epitypes.

PubMed

Carneros, Elena; Yakovlev, Igor; Viejo, Marcos; Olsen, Jorunn E; Fossdal, Carl Gunnar

2017-09-01

Epigenetic memory affects the timing of bud burst phenology and the expression of bud burst-related genes in genetically identical Norway spruce epitypes in a manner usually associated with ecotypes. In Norway spruce, a temperature-dependent epigenetic memory established during embryogenesis affects the timing of bud burst and bud set in a reproducible and predictable manner. We hypothesize that the clinal variation in these phenological traits, which is associated with adaptation to growth under frost-free conditions, has an epigenetic component. In Norway spruce, dehydrins (DHNs) have been associated with extreme frost tolerance. DHN transcript levels decrease gradually prior to flushing, a time when trees are highly sensitive to frost. Furthermore, EARLY BUD BREAK 1 genes (EBB1) and the FT-TFL1-LIKE 2-gene (PaFTL2) were previously suggested to be implied in control of bud phenology. Here we report an analysis of transcript levels of 12 DHNs, 3 EBB1 genes and FTL2 in epitypes of the same genotype generated at different epitype-inducing temperatures, before and during spring bud burst. Earlier flushing of epitypes originating from embryos developed at 18 °C as compared to 28 °C, was associated with differential expression of these genes between epitypes and between buds and last year's needles. The majority of these genes showed significantly different expressions between epitypes in at least one time point. The general trend in DHN expression pattern in buds showed the expected reduction in transcript levels when approaching flushing, whereas, surprisingly, transcript levels peaked later in needles, mainly at the moment of bud burst. Collectively, our results demonstrate that the epigenetic memory of temperature during embryogenesis affects bud burst phenology and expression of the bud burst-related DHN, EBB1 and FTL2 genes in genetically identical Norway spruce epitypes.

Mitigation in Multiple Effects of Graphene Oxide Toxicity in Zebrafish Embryogenesis Driven by Humic Acid.

PubMed

Chen, Yuming; Ren, Chaoxiu; Ouyang, Shaohu; Hu, Xiangang; Zhou, Qixing

2015-08-18

Graphene oxide (GO) is a widely used carbonaceous nanomaterial. To date, the influence of natural organic matter (NOM) on GO toxicity in aquatic vertebrates has not been reported. During zebrafish embryogenesis, GO induced a significant hatching delay and cardiac edema. The intensive interactions of GO with the chorion induces damage to chorion protuberances, excessive generation of (•)OH, and changes in protein secondary structure. In contrast, humic acid (HA), a ubiquitous form of NOM, significantly relieved the above adverse effects. HA reduced the interactions between GO and the chorion and mitigated chorion damage by regulating the morphology, structures, and surface negative charges of GO. HA also altered the uptake and deposition of GO and decreased the aggregation of GO in embryonic yolk cells and deep layer cells. Furthermore, HA mitigated the mitochondrial damage and oxidative stress induced by GO. This work reveals a feasible antidotal mechanism for GO in the presence of NOM and avoids overestimating the risks of GO in the natural environment.

Late-Onset Psychogenic Chronic Phonic-Tics.

PubMed

Vale, Thiago Cardoso; Pedroso, José Luiz; Knobel, Marcos; Knobel, Elias

2016-01-01

Tics beginning in late adulthood often have an identifiable etiology. Psychogenic tics with onset around 60 years of age are rarely described in the literature. A 67-year-old female had experienced phonic tics for 8 years. Episodes occurred without premonitory sensations and precipitant factors, and she could not suppress them. She had no history of childhood tic disorder, and secondary causes of tics were excluded. She was diagnosed with psychogenic tics and treated with quetiapine with mild improvement. When physicians are faced with no identifiable cause of tics combined with certain clinical clues, a psychogenic disorder must be suspected.

Hippocampal Morphology and Distinguishing Late-Onset From Early-Onset Elderly Depression

PubMed Central

Ballmaier, Martina; Narr, Katherine L.; Toga, Arthur W.; Elderkin-Thompson, Virginia; Thompson, Paul M.; Hamilton, Liberty; Haroon, Ebrahim; Pham, Daniel; Heinz, Andreas; Kumar, Anand

2010-01-01

Objective Despite evidence for hippocampal abnormalities in elderly depression, it is unknown whether these changes are regionally specific. This study used three-dimensional mapping techniques to identify regional hippocampal abnormalities in early- and late-onset depression. Neuropsychological correlates of hippocampal morphology were also investigated. Method With high-resolution magnetic resonance imaging, hippocampal morphology was compared among elderly patients with early- (N=24) and late-onset (N=22) depression and comparison subjects (N=34). Regional structural abnormalities were identified by comparing distances, measured from homologous hippocampal surface points to the central core of each individual’s hippocampal surface model, between groups. Results Hippocampal volumes differed between depressed patients and comparison subjects but not between patients with early- and late-onset depression. However, statistical mapping results showed that regional surface contractions were significantly pronounced in late-compared to early-onset depression in the anterior of the subiculum and lateral posterior of the CA1 subfield in the left hemisphere. Significant shape differences were observed bilaterally in anterior CA1–CA3 subfields and the subiculum in patients in relation to comparison subjects. These results were similar when each disease group was separately compared to comparison subjects. Hippocampal surface contractions significantly correlated with memory measures among late- but not early-onset depressed patients or comparison subjects. Conclusions More pronounced regional volume deficits and their associations with memory in late-onset depression may suggest that these patients are more likely to develop cognitive impairment over time than individuals with early-onset depression. Mapping regional hippocampal abnormalities and their cognitive correlates may help guide research in defining risk profiles and treatment strategies. PMID:17986679

Psychosocial Correlates of Contraceptive Practices during Late Adolescence.

ERIC Educational Resources Information Center

Lagana, Luciana

1999-01-01

Reviews the literature on psychosocial correlates of contraceptive practices among sexually active late adolescents. Helps identify subgroups of adolescents who either do not use or misuse contraceptive means, putting them at risk for unwanted pregnancy, AIDS, and other sexually transmitted diseases. Promotes further research on those variables…

Darker eggs of mosquitoes resist more to dry conditions: Melanin enhances serosal cuticle contribution in egg resistance to desiccation in Aedes, Anopheles and Culex vectors.

PubMed

Farnesi, Luana C; Vargas, Helena C M; Valle, Denise; Rezende, Gustavo L

2017-10-01

Mosquito vectors lay their white eggs in the aquatic milieu. During early embryogenesis water passes freely through the transparent eggshell, which at this moment is composed of exochorion and endochorion. Within two hours the endochorion darkens via melanization but even so eggs shrink and perish if removed from moisture. However, during mid-embryogenesis, cells of the extraembryonic serosa secrete the serosal cuticle, localized right below the endochorion, becoming the third and innermost eggshell layer. Serosal cuticle formation greatly reduces water flow and allows egg survival outside the water. The degree of egg resistance to desiccation (ERD) at late embryogenesis varies among different species: Aedes aegypti, Anopheles aquasalis and Culex quinquefasciatus eggs can survive in a dry environment for ≥ 72, 24 and 5 hours, respectively. In some adult insects, darker-body individuals show greater resistance to desiccation than lighter ones. We asked if egg melanization enhances mosquito serosal cuticle-dependent ERD. Species with higher ERD at late embryogenesis exhibit more melanized eggshells. The melanization-ERD hypothesis was confirmed employing two Anopheles quadrimaculatus strains, the wild type and the mutant GORO, with a dark-brown and a golden eggshell, respectively. In all cases, serosal cuticle formation is fundamental for the establishment of an efficient ERD but egg viability outside the water is much higher in mosquitoes with darker eggshells than in those with lighter ones. The finding that pigmentation influences egg water balance is relevant to understand the evolutionary history of insect egg coloration. Since eggshell and adult cuticle pigmentation ensure insect survivorship in some cases, they should be considered regarding species fitness and novel approaches for vector or pest insects control.

Darker eggs of mosquitoes resist more to dry conditions: Melanin enhances serosal cuticle contribution in egg resistance to desiccation in Aedes, Anopheles and Culex vectors

PubMed Central

Farnesi, Luana C.; Vargas, Helena C. M.; Valle, Denise

2017-01-01

Mosquito vectors lay their white eggs in the aquatic milieu. During early embryogenesis water passes freely through the transparent eggshell, which at this moment is composed of exochorion and endochorion. Within two hours the endochorion darkens via melanization but even so eggs shrink and perish if removed from moisture. However, during mid-embryogenesis, cells of the extraembryonic serosa secrete the serosal cuticle, localized right below the endochorion, becoming the third and innermost eggshell layer. Serosal cuticle formation greatly reduces water flow and allows egg survival outside the water. The degree of egg resistance to desiccation (ERD) at late embryogenesis varies among different species: Aedes aegypti, Anopheles aquasalis and Culex quinquefasciatus eggs can survive in a dry environment for ≥ 72, 24 and 5 hours, respectively. In some adult insects, darker-body individuals show greater resistance to desiccation than lighter ones. We asked if egg melanization enhances mosquito serosal cuticle-dependent ERD. Species with higher ERD at late embryogenesis exhibit more melanized eggshells. The melanization-ERD hypothesis was confirmed employing two Anopheles quadrimaculatus strains, the wild type and the mutant GORO, with a dark-brown and a golden eggshell, respectively. In all cases, serosal cuticle formation is fundamental for the establishment of an efficient ERD but egg viability outside the water is much higher in mosquitoes with darker eggshells than in those with lighter ones. The finding that pigmentation influences egg water balance is relevant to understand the evolutionary history of insect egg coloration. Since eggshell and adult cuticle pigmentation ensure insect survivorship in some cases, they should be considered regarding species fitness and novel approaches for vector or pest insects control. PMID:29084225

Argonaute-1 functions as a mitotic regulator by controlling Cyclin B during Drosophila early embryogenesis.

PubMed

Pushpavalli, Sreerangam N C V L; Sarkar, Arpita; Bag, Indira; Hunt, Clayton R; Ramaiah, M Janaki; Pandita, Tej K; Bhadra, Utpal; Pal-Bhadra, Manika

2014-02-01

The role of Ago-1 in microRNA (miRNA) biogenesis has been thoroughly studied, but little is known about its involvement in mitotic cell cycle progression. In this study, we established evidence of the regulatory role of Ago-1 in cell cycle control in association with the G2/M cyclin, cyclin B. Immunostaining of early embryos revealed that the maternal effect gene Ago-1 is essential for proper chromosome segregation, mitotic cell division, and spindle fiber assembly during early embryonic development. Ago-1 mutation resulted in the up-regulation of cyclin B-Cdk1 activity and down-regulation of p53, grp, mei-41, and wee1. The increased expression of cyclin B in Ago-1 mutants caused less stable microtubules and probably does not produce enough force to push the nuclei to the cortex, resulting in a decreased number of pole cells. The role of cyclin B in mitotic defects was further confirmed by suppressing the defects in the presence of one mutant copy of cyclin B. We identified involvement of 2 novel embryonic miRNAs--miR-981 and miR--317-for spatiotemporal regulation of cyclin B. In summary, our results demonstrate that the haploinsufficiency of maternal Ago-1 disrupts mitotic chromosome segregation and spindle fiber assembly via miRNA-guided control during early embryogenesis in Drosophila. The increased expression of cyclin B-Cdk1 and decreased activity of the Cdk1 inhibitor and cell cycle checkpoint proteins (mei-41 and grp) in Ago-1 mutant embryos allow the nuclei to enter into mitosis prematurely, even before completion of DNA replication. Thus, our results have established a novel role of Ago-1 as a regulator of the cell cycle.

The role of fundus autofluorescence in late-onset retinitis pigmentosa (LORP) diagnosis.

PubMed

Lee, Tamara J; Hwang, John C; Chen, Royce W S; Lima, Luiz H; Wang, Nan-Kai; Tosi, Joaquin; Freund, K Bailey; Yannuzzi, Lawrence A; Tsang, Stephen H

2014-09-01

To demonstrate the utility and characteristics of fundus autofluorescence in late-onset retinitis pigmentosa. Observational case series. Patients diagnosed with late-onset retinitis pigmentosa were identified retrospectively in an institutional setting. Twelve eyes of six patients were identified and medical records were reviewed. All patients presented with slowly progressive peripheral field loss and initial clinical examination revealed only subtle retinal changes. There was a notable lack of intraretinal pigment migration in all patients. Five out of six patients underwent magnetic resonance imaging of the brain to rule out intracranial processes and all were referred from another ophthalmologist for further evaluation. Fundus autofluorescence was ultimately employed in all patients and revealed more extensive retinal pathology than initially appreciated on clinical examination. Fundus autofluorescence directed the workup toward a retinal etiology in all cases and led to the eventual diagnosis of late-onset retinitis pigmentosa through electroretinogram testing. Fundus autofluorescence may be a more sensitive marker for retinal pathology than stereo fundus biomicroscopy alone in late-onset retinitis pigmentosa. Early use of fundus autofluorescence imaging in the evaluation of patients with subtle retinal lesions and complaints of peripheral field loss may be an effective strategy for timely and cost-efficient diagnosis.

A Regulatory Network-Based Approach Dissects Late Maturation Processes Related to the Acquisition of Desiccation Tolerance and Longevity of Medicago truncatula Seeds1[C][W][OPEN

PubMed Central

Verdier, Jerome; Lalanne, David; Pelletier, Sandra; Torres-Jerez, Ivone; Righetti, Karima; Bandyopadhyay, Kaustav; Leprince, Olivier; Chatelain, Emilie; Vu, Benoit Ly; Gouzy, Jerome; Gamas, Pascal; Udvardi, Michael K.; Buitink, Julia

2013-01-01

In seeds, desiccation tolerance (DT) and the ability to survive the dry state for prolonged periods of time (longevity) are two essential traits for seed quality that are consecutively acquired during maturation. Using transcriptomic and metabolomic profiling together with a conditional-dependent network of global transcription interactions, we dissected the maturation events from the end of seed filling to final maturation drying during the last 3 weeks of seed development in Medicago truncatula. The network revealed distinct coexpression modules related to the acquisition of DT, longevity, and pod abscission. The acquisition of DT and dormancy module was associated with abiotic stress response genes, including late embryogenesis abundant (LEA) genes. The longevity module was enriched in genes involved in RNA processing and translation. Concomitantly, LEA polypeptides accumulated, displaying an 18-d delayed accumulation compared with transcripts. During maturation, gulose and stachyose levels increased and correlated with longevity. A seed-specific network identified known and putative transcriptional regulators of DT, including ABSCISIC ACID-INSENSITIVE3 (MtABI3), MtABI4, MtABI5, and APETALA2/ ETHYLENE RESPONSE ELEMENT BINDING PROTEIN (AtAP2/EREBP) transcription factor as major hubs. These transcriptional activators were highly connected to LEA genes. Longevity genes were highly connected to two MtAP2/EREBP and two basic leucine zipper transcription factors. A heat shock factor was found at the transition of DT and longevity modules, connecting to both gene sets. Gain- and loss-of-function approaches of MtABI3 confirmed 80% of its predicted targets, thereby experimentally validating the network. This study captures the coordinated regulation of seed maturation and identifies distinct regulatory networks underlying the preparation for the dry and quiescent states. PMID:23929721

Impact of late radiation effects on cancer survivor children: an integrative review

PubMed Central

Coura, Cibeli Fernandes; Modesto, Patrícia Cláudia

2016-01-01

ABSTRACT We aimed to identify the late effects of radiation exposure in pediatric cancer survivors. An integrated literature review was performed in the databases MEDLINE and LILACS and SciELO. Included were articles in Portuguese and English, published over the past 10 years, using the following keywords: “neoplasias/neoplasms” AND “radioterapia/radiotherapy” AND “radiação/radiation”. After analysis, 14 articles - published in nine well-known journals - met the inclusion criteria. The publications were divided into two categories: “Late endocrine effects” and “Late non-endocrine effects”. Considering the increased survival rates in children who had cancer, the impact of late effects of exposure to radiation during radiological examinations for diagnosis and treatment was analyzed. Childhood cancer survivors were exposed to several late effects and should be early and regularly followed up, even when exposed to low radiation doses. PMID:26313432

Motility screen identifies Drosophila IGF-II mRNA-binding protein--zipcode-binding protein acting in oogenesis and synaptogenesis.

PubMed

Boylan, Kristin L M; Mische, Sarah; Li, Mingang; Marqués, Guillermo; Morin, Xavier; Chia, William; Hays, Thomas S

2008-02-01

The localization of specific mRNAs can establish local protein gradients that generate and control the development of cellular asymmetries. While all evidence underscores the importance of the cytoskeleton in the transport and localization of RNAs, we have limited knowledge of how these events are regulated. Using a visual screen for motile proteins in a collection of GFP protein trap lines, we identified the Drosophila IGF-II mRNA-binding protein (Imp), an ortholog of Xenopus Vg1 RNA binding protein and chicken zipcode-binding protein. In Drosophila, Imp is part of a large, RNase-sensitive complex that is enriched in two polarized cell types, the developing oocyte and the neuron. Using time-lapse confocal microscopy, we establish that both dynein and kinesin contribute to the transport of GFP-Imp particles, and that regulation of transport in egg chambers appears to differ from that in neurons. In Drosophila, loss-of-function Imp mutations are zygotic lethal, and mutants die late as pharate adults. Imp has a function in Drosophila oogenesis that is not essential, as well as functions that are essential during embryogenesis and later development. Germline clones of Imp mutations do not block maternal mRNA localization or oocyte development, but overexpression of a specific Imp isoform disrupts dorsal/ventral polarity. We report here that loss-of-function Imp mutations, as well as Imp overexpression, can alter synaptic terminal growth. Our data show that Imp is transported to the neuromuscular junction, where it may modulate the translation of mRNA targets. In oocytes, where Imp function is not essential, we implicate a specific Imp domain in the establishment of dorsoventral polarity.

Sperm cryopreservation affects postthaw motility, but not embryogenesis or larval growth in the Brazilian fish Brycon insignis (Characiformes).

PubMed

Viveiros, A T M; Isaú, Z A; Caneppele, D; Leal, M C

2012-09-01

Sperm cryopreservation is an important method for preserving genetic information and facilitating artificial reproduction. The objective was to investigate whether the cryopreservation process affects postthaw sperm motility, embryogenesis, and larval growth in the fish Brycon insignis. Sperm was diluted in methyl glycol and Beltsville Thawing solution, frozen in a nitrogen vapor vessel (dry shipper) and stored in liquid nitrogen. Half of the samples were evaluated both subjectively (% of motile sperm and motility quality score-arbitrary grading system from 0 [no movement] to 5 [rapidly swimming sperm]) and in a computer-assisted sperm analyzer (CASA; percentage of motile sperm and velocity). The other half was used for fertilization and the evaluation of embryogenesis (cleavage and gastrula stages), hatching rate, percentage of larvae with normal development and larval growth up to 112 days posthatching (dph). Fresh sperm was analyzed subjectively (percentage of motile sperm and motility quality score) and used as the control. In the subjective analysis, sperm motility significantly decreased from 100% motile sperm and quality score of 5 in fresh sperm to 54% motile sperm and quality score of 3 after thawing. Under computer-assisted sperm analyzer evaluation, postthaw sperm had 67% motile sperm, 122 μm/sec of curvilinear velocity, 87 μm/sec of straight-line velocity and 103 μm/sec of average path velocity. There were no significant differences between progenies (pooled data) for the percentage of viable embryos in cleavage (62%) or gastrula stages (24%) or in the hatching rate (24%), percentage of normal hatched larvae (93%), larval body weight (39.8 g), or standard length (12.7 cm) at 112 days posthatching. Based on these findings, cryopreserved sperm can be used as a tool to restore the population of endangered species, such as B. insignis, as well as for aquaculture purposes, without any concern regarding quality of the offspring. Copyright © 2012 Elsevier

Financial Conflicts Facing Late-Life Remarried Alzheimer's Disease Caregivers

ERIC Educational Resources Information Center

Sherman, Carey Wexler; Bauer, Jean W.

2008-01-01

This qualitative study explores financial conflicts faced by late-life remarried wives providing care for their husbands with Alzheimer's disease. Interviews with 9 women identified intergenerational secrets and tensions regarding financial and inheritance decisions. Participants' remarried spouse status, underlying family boundary ambiguities,…

Mosasaurs (Reptilia) from the late Maastrichtian (Late Cretaceous) of northern Patagonia (Río Negro, Argentina)

NASA Astrophysics Data System (ADS)

Fernández, Marta; Martin, James; Casadío, Silvio

2008-03-01

A diverse assemblage of mosasaurs was recently recovered from the Jagüel Formation (late Maastrichtian) exposed at three localities of northern Patagonia (Río Negro, Argentina). Four taxa (three mosasaurines and a plioplatecarpine) have been identified, and three of these marine reptiles can be identified at lower taxonomic levels: Mosasaurus sp. aff. M. hoffmanni, Plioplatecarpus sp., and Prognathodon sp. These occurrences are significant because they represent the first diagnostic material at generic level exhumed from Patagonia and include one of the youngest mosasaurs found worldwide. One of the specimens described herein was found only 1.5 m below the Cretaceous/Tertiary boundary. Only mosasaurs from Antarctica found within a meter of the boundary are known to occur higher in the geologic section.

FLASH is essential during early embryogenesis and cooperates with p73 to regulate histone gene transcription.

PubMed

De Cola, A; Bongiorno-Borbone, L; Bianchi, E; Barcaroli, D; Carletti, E; Knight, R A; Di Ilio, C; Melino, G; Sette, C; De Laurenzi, V

2012-02-02

Replication-dependent histone gene expression is a fundamental process occurring in S-phase under the control of the cyclin-E/CDK2 complex. This process is regulated by a number of proteins, including Flice-Associated Huge Protein (FLASH) (CASP8AP2), concentrated in specific nuclear organelles known as HLBs. FLASH regulates both histone gene transcription and mRNA maturation, and its downregulation in vitro results in the depletion of the histone pull and cell-cycle arrest in S-phase. Here we show that the transcription factor p73 binds to FLASH and is part of the complex that regulates histone gene transcription. Moreover, we created a novel gene trap to disrupt FLASH in mice, and we show that homozygous deletion of FLASH results in early embryonic lethality, owing to arrest of FLASH(-/-) embryos at the morula stage. These results indicate that FLASH is an essential, non-redundant regulator of histone transcription and cell cycle during embryogenesis.

EXPERIMENTAL STUDIES ON EMBRYOGENESIS IN HYDROZOANS (TRACHYLINA AND SIPHONOPHORA) WITH DIRECT DEVELOPMENT.

PubMed

Freeman, Gary

1983-12-01

The normal embryology of the trachymedusa Aglantha digitale and the siphonophores Nanomia cara and Muggiaea atlantica is described. Marking experiments on these embryos indicate that the site of first cleavage initiation corresponds to the oral pole of the oral-aboral axis. In Muggiaea the plane of the first cleavage corresponds to the plane of bilateral symmetry. Experiments in which presumptive aboral and oral regions are isolated from these embryos at different stages of development indicate that there is an early determination of different regions along this axis. Only the oral region of the Muggiaea embryo has the ability to regulate. These eggs have a pronounced centrolecithal organization. As a consequence of cleavage, the outer ectoplasmic layer of the egg ends up in the cells that form the ectoderm, while the inner or endoplasmic region of the egg ends up in the cells that form the endoderm. Experimentally created fragments of fertilized eggs that contain only ectoplasm differentiate to form an unorganized ectodermal cell mass, indicating that endoplasm is necessary in order to differentiate endoderm. The process of embryogenesis in these animals and the developmental mechanisms they use are very different from those used by hydrozoans with indirect development. These embryos use a suite of developmental mechanisms which are very similar to those used by ctenophores. The significance of this similarity is discussed.

Genetic and Hormonal Regulation of Chlorophyll Degradation during Maturation of Seeds with Green Embryos.

PubMed

Smolikova, Galina; Dolgikh, Elena; Vikhnina, Maria; Frolov, Andrej; Medvedev, Sergei

2017-09-16

The embryos of some angiosperms (usually referred to as chloroembryos) contain chlorophylls during the whole period of embryogenesis. Developing embryos have photochemically active chloroplasts and are able to produce assimilates, further converted in reserve biopolymers, whereas at the late steps of embryogenesis, seeds undergo dehydration, degradation of chlorophylls, transformation of chloroplast in storage plastids, and enter the dormancy period. However, in some seeds, the process of chlorophyll degradation remains incomplete. These residual chlorophylls compromise the quality of seed material in terms of viability, nutritional value, and shelf life, and represent a serious challenge for breeders and farmers. The mechanisms of chlorophyll degradation during seed maturation are still not completely understood, and only during the recent decades the main pathways and corresponding enzymes could be characterized. Among the identified players, the enzymes of pheophorbide a oxygenase pathway and the proteins encoded by STAY GREEN ( SGR ) genes are the principle ones. On the biochemical level, abscisic acid (ABA) is the main regulator of seed chlorophyll degradation, mediating activity of corresponding catabolic enzymes on the transcriptional level. In general, a deep insight in the mechanisms of chlorophyll degradation is required to develop the approaches for production of chlorophyll-free high quality seeds.

The Role of Fundus Autofluorescence in Late-Onset Retinitis Pigmentosa (LORP) Diagnosis

PubMed Central

Lee, Tamara J.; Hwang, John C.; Chen, Royce W. S.; Lima, Luiz H.; Wang, Nan-Kai; Tosi, Joaquin; Freund, K. Bailey; Yannuzzi, Lawrence A.; Tsang, Stephen H.

2015-01-01

Purpose To demonstrate the utility and characteristics of fundus autofluorescence in late-onset retinitis pigmentosa. Methods Observational case series. Patients diagnosed with late-onset retinitis pigmentosa were identified retrospectively in an institutional setting. Twelve eyes of six patients were identified and medical records were reviewed. Results All patients presented with slowly progressive peripheral field loss and initial clinical examination revealed only subtle retinal changes. There was a notable lack of intraretinal pigment migration in all patients. Five out of six patients underwent magnetic resonance imaging of the brain to rule out intracranial processes and all were referred from another ophthalmologist for further evaluation. Fundus autofluorescence was ultimately employed in all patients and revealed more extensive retinal pathology than initially appreciated on clinical examination. Fundus autofluorescence directed the workup toward a retinal etiology in all cases and led to the eventual diagnosis of late-onset retinitis pigmentosa through electroretinogram testing. Conclusion Fundus autofluorescence may be a more sensitive marker for retinal pathology than stereo fundus biomicroscopy alone in late-onset retinitis pigmentosa. Early use of fundus autofluorescence imaging in the evaluation of patients with subtle retinal lesions and complaints of peripheral field loss may be an effective strategy for timely and cost-efficient diagnosis. PMID:23899229

Subcellular localisations of the CPTI collection of YFP-tagged proteins in Drosophila embryos

PubMed Central

Lye, Claire M.; Naylor, Huw W.; Sanson, Bénédicte

2014-01-01

A key challenge in the post-genomic area is to identify the function of the genes discovered, with many still uncharacterised in all metazoans. A first step is transcription pattern characterisation, for which we now have near whole-genome coverage in Drosophila. However, we have much more limited information about the expression and subcellular localisation of the corresponding proteins. The Cambridge Protein Trap Consortium generated, via piggyBac transposition, over 600 novel YFP-trap proteins tagging just under 400 Drosophila loci. Here, we characterise the subcellular localisations and expression patterns of these insertions, called the CPTI lines, in Drosophila embryos. We have systematically analysed subcellular localisations at cellularisation (stage 5) and recorded expression patterns at stage 5, at mid-embryogenesis (stage 11) and at late embryogenesis (stages 15-17). At stage 5, 31% of the nuclear lines (41) and 26% of the cytoplasmic lines (67) show discrete localisations that provide clues on the function of the protein and markers for organelles or regions, including nucleoli, the nuclear envelope, nuclear speckles, centrosomes, mitochondria, the endoplasmic reticulum, Golgi, lysosomes and peroxisomes. We characterised the membranous/cortical lines (102) throughout stage 5 to 10 during epithelial morphogenesis, documenting their apico-basal position and identifying those secreted in the extracellular space. We identified the tricellular vertices as a specialized membrane domain marked by the integral membrane protein Sidekick. Finally, we categorised the localisation of the membranous/cortical proteins during cytokinesis. PMID:25294944

Paleoecological evaluation of Late Eocene biostratigraphic zonations of the Pacific Coast of North America

USGS Publications Warehouse

McDougall, Kristin

1980-01-01

The late Eocene zonal criteria of the west coast of North America are to a large extent controlled by paleoecology and, therefore, the correlation of coeval but environmentally different benthic foraminiferal faunas cannot be achieved before paleoecological control of the biostratigraphy is understood. The faunal trends, morphology, characteristic occurrences and estimated upper depth limits of the benthic foraminifers and associated microfossils in the Oregon and Washington study sections lead to the recognition of paleoecologic facies. The interpretation of these late Eocene facies as bathymetric and low-oxygen facies is based on analogous late Eocene and Holocene assemblages. The paleoecologic facies criteria are often identical to the stage and zonal criteria. In the California zonal schemes, the Narizian zones are identified by lower and middle bathyal faunas whereas the Refugian zones are identified by outer neritic and upper bathyal faunas. The Washington late Eocene zones are identified by middle bathyal and transported neritic faunas. Modifications of the existing zonal schemes such that time and not paleoecology is the controlling factor results in a zonation that synthesizes the existing zonal schemes, recognizes regional stratigraphic ranges of diagnostic species, and removes paleoecologically controlled species occurrences. The late Narizian encompasses a bathyal and a neritic facies. The bathyal facies is correlative with a modified Bulimina corrugata Zone of California and the Uvigerina cf. U. yazooensis Zone of Washington. The neritic late Narizian facies corresponds to a modified Bulimina schencki-Plectofrondicularia cf. P. jenkinsi Zone of Washington and a modified Amphimorphina jenkinsi Zone of California. The Refugian can also be divided into a neritic and a bathyal facies. Although the early and late subdivisions of this stage are tentative, the early Refugian is equivalent to the modified versions of the Cibicides haydoni and the Uvigerina

An Observation-Driven Agent-Based Modeling and Analysis Framework for C. elegans Embryogenesis.

PubMed

Wang, Zi; Ramsey, Benjamin J; Wang, Dali; Wong, Kwai; Li, Husheng; Wang, Eric; Bao, Zhirong

2016-01-01

With cutting-edge live microscopy and image analysis, biologists can now systematically track individual cells in complex tissues and quantify cellular behavior over extended time windows. Computational approaches that utilize the systematic and quantitative data are needed to understand how cells interact in vivo to give rise to the different cell types and 3D morphology of tissues. An agent-based, minimum descriptive modeling and analysis framework is presented in this paper to study C. elegans embryogenesis. The framework is designed to incorporate the large amounts of experimental observations on cellular behavior and reserve data structures/interfaces that allow regulatory mechanisms to be added as more insights are gained. Observed cellular behaviors are organized into lineage identity, timing and direction of cell division, and path of cell movement. The framework also includes global parameters such as the eggshell and a clock. Division and movement behaviors are driven by statistical models of the observations. Data structures/interfaces are reserved for gene list, cell-cell interaction, cell fate and landscape, and other global parameters until the descriptive model is replaced by a regulatory mechanism. This approach provides a framework to handle the ongoing experiments of single-cell analysis of complex tissues where mechanistic insights lag data collection and need to be validated on complex observations.

Neonatal Outcomes of Low-Risk, Late-Preterm Twins Compared With Late-Preterm Singletons.

PubMed

Salem, Shimrit Yaniv; Kibel, Mia; Asztalos, Elizabeth; Zaltz, Arthur; Barrett, Jon; Melamed, Nir

2017-09-01

To test the hypothesis that the risk of neonatal morbidity among late-preterm twins is similar to that of late-preterm singletons. We conducted a retrospective cohort study of all women with twin or singleton pregnancy who gave birth during the late-preterm period in a single tertiary center between 2008 and 2015. Neonatal outcomes of low-risk, late-preterm twins were compared with those of low-risk, late-preterm singletons. The primary outcome was the same primary composite respiratory morbidity variable that was used in the randomized controlled trial of Gyamfi-Bannerman et al on the administration of antenatal corticosteroids during the late-preterm period. A total of 922 singleton and 721 twin late-preterm neonates met the inclusion criteria. The rates of composite respiratory morbidity and severe composite respiratory morbidity were similar for twins and singletons (8.3% compared with 7.4%, P=.5 and 6.8% compared with 6.0%, P=.5, respectively), but were lower than the rates of the same composite respiratory morbidity variable in the randomized controlled study described previously. The odds for respiratory morbidity were similar for twins and singletons for both composite respiratory morbidity (adjusted odds ratio [OR] 0.73, 95% CI 0.48-1.12) and severe composite respiratory morbidity (adjusted OR 0.79, 95% CI 0.50-1.24). The risk of respiratory morbidity among late-preterm twins is similar to that of late-preterm singletons. Still, the low absolute rates of the composite respiratory morbidity in our population suggest that administration of antenatal corticosteroids may be mostly justified among neonates born closer to 34 weeks of gestation.

G9a histone methyltransferase plays a dominant role in euchromatic histone H3 lysine 9 methylation and is essential for early embryogenesis

PubMed Central

Tachibana, Makoto; Sugimoto, Kenji; Nozaki, Masami; Ueda, Jun; Ohta, Tsutomu; Ohki, Misao; Fukuda, Mikiko; Takeda, Naoki; Niida, Hiroyuki; Kato, Hiroyuki; Shinkai, Yoichi

2002-01-01

Covalent modification of histone tails is crucial for transcriptional regulation, mitotic chromosomal condensation, and heterochromatin formation. Histone H3 lysine 9 (H3-K9) methylation catalyzed by the Suv39h family proteins is essential for establishing the architecture of pericentric heterochromatin. We recently identified a mammalian histone methyltransferase (HMTase), G9a, which has strong HMTase activity towards H3-K9 in vitro. To investigate the in vivo functions of G9a, we generated G9a-deficient mice and embryonic stem (ES) cells. We found that H3-K9 methylation was drastically decreased in G9a-deficient embryos, which displayed severe growth retardation and early lethality. G9a-deficient ES cells also exhibited reduced H3-K9 methylation compared to wild-type cells, indicating that G9a is a dominant H3-K9 HMTase in vivo. Importantly, the loss of G9a abolished methylated H3-K9 mostly in euchromatic regions. Finally, G9a exerted a transcriptionally suppressive function that depended on its HMTase activity. Our results indicate that euchromatic H3-K9 methylation regulated by G9a is essential for early embryogenesis and is involved in the transcriptional repression of developmental genes. PMID:12130538

Sea Urchin Embryogenesis as Bioindicators of Marine Pollution in Impact Areas of the Sea of Japan/East Sea and the Sea of Okhotsk.

PubMed

Lukyanova, Olga N; Zhuravel, Elena V; Chulchekov, Denis N; Mazur, Andrey A

2017-08-01

The embryogenesis of the sea urchin sand dollar Scaphechinus mirabilis was used as bioindicators of seawater quality from the impact areas of the Sea of Japan/East Sea (Peter the Great Bay) and the Sea of Okhotsk (northwestern shelf of Sakhalin Island and western shelf of Kamchatka Peninsula). Fertilization membrane formation, first cleavage, blastula formation, gastrulation, and 2-armed and 4-armed pluteus formation have been analyzed and a number of abnormalities were calculated. Number of embryogenesis anomalies in sand dollar larvae exposed to sea water from different stations in Peter the Great Bay corresponds to pollution level at each area. The Sea of Okhotsk is the main fishing area for Russia. Anthropogenic impact on the marine ecosystem is caused by fishing and transport vessels mainly. But two shelf areas are considered as "hot spots" due to oil and gas drilling. Offshore oil exploitation on the northeastern Sakhalin Island has been started and at present time oil is being drill on oil-extracting platforms continuously. Significant reserves of hydrocarbons are prospected on western Kamchatka shelf, and exploitation drilling in this area was intensified in 2014. A higher number of abnormalities at gastrula and pluteus stages (19-36%) were detected for the stations around oil platforms near Sakhalin Island. On the western Kamchatka shelf number of abnormalities was 7-21%. Such anomalies as exogastrula, incomplete development of pairs of arms were not observed at all; only the delay of development was registered. Eggs, embryos, and larvae of sea urchins are the suitable bioindicators of early disturbances caused by marine pollution in impact ecosystems.

Long-term sustainability in Davis Late Successional Reserve

Treesearch

Jim Stone; Joan Kittrell

2004-01-01

A pilot watershed analysis along with the Davis Late Successional Reserve analysis in the range of the northern spotted owl identified potential loss of suitable habitat, reduction in the numbers of large trees, and lack of replacements for large trees. A variety of silvicultural thinning techniques has been used to address these important issues and to move toward a...

Lateness to School Remediation Game

ERIC Educational Resources Information Center

Ugwuegbulam, Charles N.; Ibrahim, Haj. Naheed

2015-01-01

Primary and secondary school in Nigeria encourage punctuality to school yet a good number of the learners came late to school. This is especially true in the case of day students. Learners who come late to school are usually punished in one way or the other yet the lateness to school phenomenon still persist. Lateness to school behaviour affects…

Myocardial late gadolinium enhancement in specific cardiomyopathies by cardiovascular magnetic resonance: a preliminary experience.

PubMed

Silva, Caterina; Moon, James C; Elkington, Andrew G; John, Anna S; Mohiaddin, Raad H; Pennell, Dudley J

2007-12-01

Late gadolinium enhancement cardiovascular magnetic resonance (CMR) can visualize myocardial interstitial abnormalities. The aim of this study was to assess whether regions of abnormal myocardium can also be visualized by late enhancement gadolinium CMR in the specific cardiomyopathies. A retrospective review of all referrals for gadolinium CMR with specific cardiomyopathy over 20 months. Nine patients with different specific cardiomyopathies were identified. Late enhancement was demonstrated in all patients, with a mean signal intensity of 390 +/- 220% compared with normal regions. The distribution pattern of late enhancement was unlike the subendocardial late enhancement related to coronary territories found in myocardial infarction. The affected areas included papillary muscles (sarcoid), the mid-myocardium (Anderson-Fabry disease, glycogen storage disease, myocarditis, Becker muscular dystrophy) and the global sub-endocardium (systemic sclerosis, Loeffler's endocarditis, amyloid, Churg-Strauss). Focal myocardial late gadolinium enhancement is found in the specific cardiomyopathies, and the pattern is distinct from that seen in infarction. Further systematic studies are warranted to assess whether the pattern and extent of late enhancement may aid diagnosis and prognostic assessment.

Emergency management in patients with late hemorrhage after pancreatoduodenectomy for a periampullary tumor.

PubMed

Jilesen, Anneke P J; Tol, Johanna A M G; Busch, Olivier R C; van Delden, Otto M; van Gulik, Thomas M; Nieveen van Dijkum, Els J M; Gouma, Dirk J

2014-09-01

The mortality rate due to late hemorrhage after surgery for periampullary tumors is high, especially in patients with anastomotic leakage. Patients usually require emergency intervention for late hemorrhage. In this study patients with late hemorrhage and their outcomes were analyzed. Furthermore, independent predictors for late hemorrhage, the need for emergency intervention, and type of intervention are reported. From a prospective database that includes 1,035 patients who underwent pancreatoduodenectomy for periampullary tumors between 1992 and 2012, patients with late hemorrhage (>24 h after index operation) were identified. Patient, disease-specific, and operation characteristics, type of intervention, and outcomes were analyzed. Emergency intervention was defined as surgical or radiological intervention in hemodynamically unstable patients. Of the 47 patients (4.5 %) with late hemorrhage, pancreatic fistula was an independent predictor for developing late hemorrhage (OR 10.2). The mortality rate in patients with late hemorrhage was 13 % compared with 1.5 % in all patients without late hemorrhage. Twenty patients required emergency intervention; 80 % underwent primary radiological intervention and 20 % primary surgical intervention. Extraluminal location of the bleeding (OR 5.6) and occurrence of a sentinel bleed (OR 6.6) are indications for emergency intervention. The type of emergency intervention needed for late hemorrhage is unpredictable. Radiological intervention is preferred, but if it fails, immediate change to surgical treatment is mandatory. This can be difficult to manage but possible when both radiological and surgical interventions are in close proximity such as in a hybrid operating room and should be considered in the emergency management of patients with late hemorrhage.

Late Afternoon Sun

NASA Technical Reports Server (NTRS)

2002-01-01

[figure removed for brevity, see original site]

This image of the northern plains of Mars shows a surface texture of hundreds of small mounds and numerous small impact craters. The THEMIS imaging team is taking advantage of the late afternoon sun illumination to image places like this where the surface may contain small scale features that are 'washed-out' by higher illumination angles. As the sun dips towards the horizon (to the left side of the image), shadows are cast. The length of the shadows can be used to estimate the height of the feature casting them - or the depth of the crater that contains the shadow. In this image the craters - even very small ones - are now partially filled by shadow making it very easy to identify them. The small bumps are not casting shadows yet, but are easily seen. These small bumps were not easily identified when the sun angle was higher (earlier in the afternoon). As this image shows, late afternoon sun illumination is wonderful for making small scale morphologic features visible.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built

Familial urothelial cell carcinoma of the bladder with autosomal dominant inheritance and late onset phenotype.

PubMed

Brown, Robin; Donnelly, Deirdre E; Allen, Derek; Loughrey, Maurice B; Morrison, Patrick J

2014-01-01

Familial Urothelial cell bladder cancer is rare. We report two families with urothelial cell carcinoma (UCC) of bladder with family history in other relatives, displaying probable autosomal dominant inheritance and a late onset pure UCC phenotype, and document the phenotype in each family. Descriptive familial study on two pedigrees over three generations. Two families with UCC bladder were identified, and the phenotype documented, each family having three cases of late onset UCC. Some cases of UCC are hereditary and may display autosomal dominant inheritance with late onset of the cancer. Clinicians should be aware of the existence of a familial late onset UCC phenotype when managing cases of UCC.

Is Travel Time to Colonoscopy Associated With Late-Stage Colorectal Cancer Among Medicare Beneficiaries in Iowa?

PubMed

Charlton, Mary E; Matthews, Kevin A; Gaglioti, Anne; Bay, Camden; McDowell, Bradley D; Ward, Marcia M; Levy, Barcey T

2016-09-01

Colorectal cancer (CRC) screening has been shown to decrease the incidence of late-stage colorectal cancer, yet a substantial proportion of Americans do not receive screening. Those in rural areas may face barriers to colonoscopy services based on travel time, and previous studies have demonstrated lower screening among rural residents. Our purpose was to assess factors associated with late-stage CRC, and specifically to determine if longer travel time to colonoscopy was associated with late-stage CRC among an insured population in Iowa. SEER-Medicare data were used to identify individuals ages 65 to 84 years old diagnosed with CRC in Iowa from 2002 to 2009. The distance between the centroid of the ZIP code of residence and the ZIP code of colonoscopy was computed for each individual who had continuous Medicare fee-for-service coverage for a 3- to 4-month period prior to diagnosis, and a professional claim for colonoscopy within that time frame. Demographic characteristics and travel times were compared between those diagnosed with early- versus late-stage CRC. Also, demographic differences between those who had colonoscopy claims identified within 3-4 months prior to diagnosis (81%) were compared to patients with no colonoscopy claims identified (19%). A total of 5,792 subjects met inclusion criteria; 31% were diagnosed with early-stage versus 69% with late-stage CRC. Those divorced or widowed (vs married) were more likely to be diagnosed with late-stage CRC (OR: 1.20, 95% CI: 1.06-1.37). Travel time was not associated with diagnosis of late-stage CRC. Among a Medicare-insured population, there was no relationship between travel time to colonoscopy and disease stage at diagnosis. It is likely that factors other than distance to colonoscopy present more pertinent barriers to screening in this insured population. Additional research should be done to determine reasons for nonadherence to screening among those with access to CRC screening services, given that over

Regulation of the Osem gene by abscisic acid and the transcriptional activator VP1: analysis of cis-acting promoter elements required for regulation by abscisic acid and VP1.

PubMed

Hattori, T; Terada, T; Hamasuna, S

1995-06-01

Osem, a rice gene homologous to the wheat Em gene, which encodes one of the late-embryogenesis abundant proteins was isolated. The gene was characterized with respect to control of transcription by abscisic acid (ABA) and the transcriptional activator VP1, which is involved in the ABA-regulated gene expression during late embryo-genesis. A fusion gene (Osem-GUS) consisting of the Osem promoter and the bacterial beta-glucuronidase (GUS) gene was constructed and tested in a transient expression system, using protoplasts derived from a suspension-cultured line of rice cells, for activation by ABA and by co-transfection with an expression vector (35S-Osvp1) for the rice VP1 (OSVP1) cDNA. The expression of Osem-GUS was strongly (40- to 150-fold) activated by externally applied ABA and by over-expression of (OS)VP1. The Osem promoter has three ACGTG-containing sequences, motif A, motif B and motif A', which resemble the abscisic acid-responsive element (ABRE) that was previously identified in the wheat Em and the rice Rab16. There is also a CATGCATG sequence, which is known as the Sph box and is shown to be essential for the regulation by VP1 of the maize anthocyanin regulatory gene C1. Focusing on these sequence elements, various mutant derivatives of the Osem promoter in the transient expression system were assayed. The analysis revealed that motif A functions not only as an ABRE but also as a sequence element required for the regulation by (OS)VP1.

The near demise and subsequent revival of classical genetics for investigating Caenorhabditis elegans embryogenesis: RNAi meets next-generation DNA sequencing.

PubMed

Bowerman, Bruce

2011-10-01

Molecular genetic investigation of the early Caenorhabditis elegans embryo has contributed substantially to the discovery and general understanding of the genes, pathways, and mechanisms that regulate and execute developmental and cell biological processes. Initially, worm geneticists relied exclusively on a classical genetics approach, isolating mutants with interesting phenotypes after mutagenesis and then determining the identity of the affected genes. Subsequently, the discovery of RNA interference (RNAi) led to a much greater reliance on a reverse genetics approach: reducing the function of known genes with RNAi and then observing the phenotypic consequences. Now the advent of next-generation DNA sequencing technologies and the ensuing ease and affordability of whole-genome sequencing are reviving the use of classical genetics to investigate early C. elegans embryogenesis.

7 CFR 920.112 - Late payments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Miscellaneous Provisions § 920.112 Late payments. Pursuant to § 920.41(a), interest will be charged at a 1.5 percent monthly simple interest rate. Assessments for kiwifruit shall be deemed late if not received... late charge will be assessed when payment becomes 30 days late. Interest and late payment charges shall...

XRCC1 Polymorphism Associated With Late Toxicity After Radiation Therapy in Breast Cancer Patients

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

Seibold, Petra; Behrens, Sabine; Schmezer, Peter

Purpose: To identify single-nucleotide polymorphisms (SNPs) in oxidative stress–related genes associated with risk of late toxicities in breast cancer patients receiving radiation therapy. Methods and Materials: Using a 2-stage design, 305 SNPs in 59 candidate genes were investigated in the discovery phase in 753 breast cancer patients from 2 prospective cohorts from Germany. The 10 most promising SNPs in 4 genes were evaluated in the replication phase in up to 1883 breast cancer patients from 6 cohorts identified through the Radiogenomics Consortium. Outcomes of interest were late skin toxicity and fibrosis of the breast, as well as an overall toxicity score (Standardized Totalmore » Average Toxicity). Multivariable logistic and linear regression models were used to assess associations between SNPs and late toxicity. A meta-analysis approach was used to summarize evidence. Results: The association of a genetic variant in the base excision repair gene XRCC1, rs2682585, with normal tissue late radiation toxicity was replicated in all tested studies. In the combined analysis of discovery and replication cohorts, carrying the rare allele was associated with a significantly lower risk of skin toxicities (multivariate odds ratio 0.77, 95% confidence interval 0.61-0.96, P=.02) and a decrease in Standardized Total Average Toxicity scores (−0.08, 95% confidence interval −0.15 to −0.02, P=.016). Conclusions: Using a stage design with replication, we identified a variant allele in the base excision repair gene XRCC1 that could be used in combination with additional variants for developing a test to predict late toxicities after radiation therapy in breast cancer patients.« less

Exposure to aripiprazole during embryogenesis: a prospective multicenter cohort study.

PubMed

Bellet, Florelle; Beyens, Marie-Noëlle; Bernard, Nathalie; Beghin, Delphine; Elefant, Elisabeth; Vial, Thierry

2015-04-01

The main purpose of this study was to evaluate the risk of major malformations after aripiprazole exposure during the embryonic period. The secondary purposes were to assess the risk of miscarriage, prematurity, fetal growth retardation and maternal complications and to describe possible neonatal adverse effects. We conducted a cohort study using data prospectively collected by the French Pharmacovigilance Centres participating to the Terappel program and the Centre de Référence sur les Agents Tératogènes between 2004 and 2011. The exposed group consisted of pregnant women exposed to aripiprazole during embryogenesis, and the unexposed group consisted of pregnant women without exposure or exposed to non-teratogenic agents. Two unexposed patients, matched for age and gestational age at call, were randomly selected for each exposed patient. Eighty-six patients were included in the exposed group and 172 in the unexposed group. Exposure to aripiprazole was not significantly associated with an increased rate of major malformations (OR 2.30, 95%CI 0.32-16.7) or miscarriage (1.66, 0.63-4.38) or gestational diabetes (1.15, 0.33-4.04) compared to non-exposure. The study revealed significantly increased rates of prematurity (OR 2.57, 95%CI 1.06-6.27) and fetal growth retardation (2.97, 1.23-7.16) in exposed newborns, difficult to interpret because of the short duration of maternal exposure. Two cases of neonatal complications were reported among the 19 newborns exposed to aripiprazole near delivery. This study failed to demonstrate a significant association between aripiprazole exposure during the embryonic period and major malformations. More powerful prospective studies are required to clarify the reproductive safety profile of aripiprazole. Copyright © 2015 John Wiley & Sons, Ltd.

Late onset hereditary episodic ataxia.

PubMed

Damak, M; Riant, F; Boukobza, M; Tournier-Lasserve, E; Bousser, M-G; Vahedi, K

2009-05-01

Episodic ataxias (EA) are hereditary paroxysmal neurological diseases with considerable clinical and genetic heterogeneity. So far seven loci have been reported and four different genes have been identified. Analysis of additional sporadic or familial cases is needed to better delineate the clinical and genetic spectrum of EA. A two generation French family with late onset episodic ataxia was examined. All consenting family members had a brain MRI with volumetric analysis of the cerebellum. Haplotype analysis was performed for the EA2 locus (19p13), the EA5 locus (2q22), the EA6 locus (5p13) and the EA7 locus (19q13). Mutation screening was performed for all exons of CACNA1A (EA2), EAAT1 (EA6) and the coding sequence of KCNA1 (EA1). Four family members had episodic ataxia with onset between 48 and 56 years of age but with heterogeneity in the severity and duration of symptoms. The two most severely affected had daily attacks of EA with a slowly progressive and disabling permanent cerebellar ataxia and a poor response to acetazolamide. Brain MRI showed in three affected members a decrease in the ratio of cerebellar volume:total intracranial volume, indicating cerebellar atrophy. No deleterious mutation was found in CACNA1A, SCA6, EAAT1 or KCNA1. In addition, the EA5 locus was excluded. A new phenotype of episodic ataxia has been described, characterised clinically by a late onset and progressive permanent cerebellar signs, and genetically by exclusion of the genes so far identified in EA.

Proteomic analysis of stipe explants reveals differentially expressed proteins involved in early direct somatic embryogenesis of the tree fern Cyathea delgadii Sternb.

PubMed

Domżalska, Lucyna; Kędracka-Krok, Sylwia; Jankowska, Urszula; Grzyb, Małgorzata; Sobczak, Mirosław; Rybczyński, Jan J; Mikuła, Anna

2017-05-01

Using cyto-morphological analysis of somatic embryogenesis (SE) in the tree fern Cyathea delgadii as a guide, we performed a comparative proteomic analysis in stipe explants undergoing direct SE. Plant material was cultured on hormone-free medium supplemented with 2% sucrose. Phenol extracted proteins were separated using two-dimensional gel electrophoresis (2-DE) and mass spectrometry was performed for protein identification. A total number of 114 differentially regulated proteins was identified during early SE, i.e. when the first cell divisions started and several-cell pro-embryos were formed. Proteins were assigned to seven functional categories: carbohydrate metabolism, protein metabolism, cell organization, defense and stress responses, amino acid metabolism, purine metabolism, and fatty acid metabolism. Carbohydrate and protein metabolism were found to be the most sensitive SE functions with the greatest number of alterations in the intensity of spots in gel. Differences, especially in non-enzymatic and structural protein abundance, are indicative for cell organization, including cytoskeleton rearrangement and changes in cell wall components. The highest induced changes concern those enzymes related to fatty acid metabolism. Global analysis of the proteome reveals several proteins that can represent markers for the first 16days of SE induction and expression in fern. The findings of this research improve the understanding of molecular processes involved in direct SE in C. delgadii. Copyright © 2017 Elsevier B.V. All rights reserved.

Palynology of late Middle Pennsylvanian coal beds in the Appalachian Basin

USGS Publications Warehouse

Eble, C.F.

2002-01-01

Fossil spores and pollen have long been recognized as valuable tools for identifying and correlating coal beds. This paper describes the palynology of late Middle Pennsylvanian coal beds in the Appalachian Basin with emphasis on forms that assist both intra- and interbasinal coal bed correlation. Stratigraphically important palynomorphs that originate in late Middle Pennsylvanian strata include Torispora securis, Murospora kosankei, Triquitrites minutus, Cadiospora magna, Mooreisporites inusitatus, and Schopfites dimorphus. Taxa that terminate in the late Middle Pennsylvanian include Radiizonates difformis, Densosporites annulatus, Dictyotriletes bireticulatus, Vestispora magna, and Savitrisporites nux. Species of Lycospora, Cirratriradites, Vestispora, and Thymospora, as well as Granasporites medius, Triquitrites sculptilis, and T. securis and their respective ranges slightly higher, in earliest Late Pennsylvanian age strata. Late Middle Pennsylvanian and earliest Late Pennsylvanian strata in the Appalachian Basin correlate with the Radiizonates difformis (RD), Mooreisporites inusitatus (MI), Schopfites colchesterensis-S. dimorphus (CP), and Lycospora granulata-Granasporites medius (GM) spore assemblage zones of the Eastern Interior, or Illinois Basin. In the Western Interior Basin, these strata correlate with the middle-upper portion of the Torispora securis-Laevigatosporites globosus (SG) and lower half of the Thymospora pseudothiessenii-Schopfites dimorphus (PD) assemblage zones. In western Europe, late Middle Pennsylvanian and earliest Late Pennsylvanian strata correlate with the middle-upper portion of the Torispora securis-T. laevigata (SL) and the middle part of the Thymospora obscura-T. thiessenii (OT) spore assemblage zones. Allegheny Formation coal beds also correlate with the Torispora securis (X) and Thymospora obscura (XI) spore assemblages, which were developed for coal beds in Great Britain. ?? 2002 Elsevier Science B.V. All rights reserved.

Neurotrophic actions of dopamine on the development of a serotonergic feeding circuit in Drosophila melanogaster

PubMed Central

2012-01-01

Background In the fruit fly, Drosophila melanogaster, serotonin functions both as a neurotransmitter to regulate larval feeding, and in the development of the stomatogastric feeding circuit. There is an inverse relationship between neuronal serotonin levels during late embryogenesis and the complexity of the serotonergic fibers projecting from the larval brain to the foregut, which correlate with perturbations in feeding, the functional output of the circuit. Dopamine does not modulate larval feeding, and dopaminergic fibers do not innervate the larval foregut. Since dopamine can function in central nervous system development, separate from its role as a neurotransmitter, the role of neuronal dopamine was assessed on the development, and mature function, of the 5-HT larval feeding circuit. Results Both decreased and increased neuronal dopamine levels in late embryogenesis during development of this circuit result in depressed levels of larval feeding. Perturbations in neuronal dopamine during this developmental period also result in greater branch complexity of the serotonergic fibers innervating the gut, as well as increased size and number of the serotonin-containing vesicles along the neurite length. This neurotrophic action for dopamine is modulated by the D2 dopamine receptor expressed during late embryogenesis in central 5-HT neurons. Animals carrying transgenic RNAi constructs to knock down both dopamine and serotonin synthesis in the central nervous system display normal feeding and fiber architecture. However, disparate levels of neuronal dopamine and serotonin during development of the circuit result in abnormal gut fiber architecture and feeding behavior. Conclusions These results suggest that dopamine can exert a direct trophic influence on the development of a specific neural circuit, and that dopamine and serotonin may interact with each other to generate the neural architecture necessary for normal function of the circuit. PMID:22413901

Reciprocal Expression of lin-41 and the microRNAs let-7 and mir-125 During Mouse Embryogenesis

PubMed Central

Schulman, Betsy R. Maller; Esquela-Kerscher, Aurora; Slack, Frank J.

2008-01-01

In C. elegans, heterochronic genes control the timing of cell fate determination during development. Two heterochronic genes, let-7 and lin-4, encode microRNAs (miRNAs) that down-regulate a third heterochronic gene lin-41 by binding to complementary sites in its 3’UTR. let-7 and lin-4 are conserved in mammals. Here we report the cloning and sequencing of mammalian lin-41 orthologs. We find that mouse and human lin-41 genes contain predicted conserved complementary sites for let-7 and the lin-4 ortholog, mir-125, in their 3’UTRs. Mouse lin-41 (Mlin-41) is temporally expressed in developing mouse embryos, most dramatically in the limb buds. Mlin-41 is down-regulated during mid-embryogenesis at the time when mouse let-7c and mir-125 RNA levels are up-regulated. Our results suggest that mammalian lin-41 is temporally regulated by miRNAs in order to direct key developmental events such as limb formation. PMID:16247770

Identification of Novel Associations of Candidate Genes with Resistance to Late Blight in Solanum tuberosum Group Phureja

PubMed Central

Álvarez, María F.; Angarita, Myrian; Delgado, María C.; García, Celsa; Jiménez-Gomez, José; Gebhardt, Christiane; Mosquera, Teresa

2017-01-01

The genetic basis of quantitative disease resistance has been studied in crops for several decades as an alternative to R gene mediated resistance. The most important disease in the potato crop is late blight, caused by the oomycete Phytophthora infestans. Quantitative disease resistance (QDR), as any other quantitative trait in plants, can be genetically mapped to understand the genetic architecture. Association mapping using DNA-based markers has been implemented in many crops to dissect quantitative traits. We used an association mapping approach with candidate genes to identify the first genes associated with quantitative resistance to late blight in Solanum tuberosum Group Phureja. Twenty-nine candidate genes were selected from a set of genes that were differentially expressed during the resistance response to late blight in tetraploid European potato cultivars. The 29 genes were amplified and sequenced in 104 accessions of S. tuberosum Group Phureja from Latin America. We identified 238 SNPs in the selected genes and tested them for association with resistance to late blight. The phenotypic data were obtained under field conditions by determining the area under disease progress curve (AUDPC) in two seasons and in two locations. Two genes were associated with QDR to late blight, a potato homolog of thylakoid lumen 15 kDa protein (StTL15A) and a stem 28 kDa glycoprotein (StGP28). Key message: A first association mapping experiment was conducted in Solanum tuberosum Group Phureja germplasm, which identified among 29 candidates two genes associated with quantitative resistance to late blight. PMID:28674545

Identification of Novel Associations of Candidate Genes with Resistance to Late Blight in Solanum tuberosum Group Phureja.

PubMed

Álvarez, María F; Angarita, Myrian; Delgado, María C; García, Celsa; Jiménez-Gomez, José; Gebhardt, Christiane; Mosquera, Teresa

2017-01-01

The genetic basis of quantitative disease resistance has been studied in crops for several decades as an alternative to R gene mediated resistance. The most important disease in the potato crop is late blight, caused by the oomycete Phytophthora infestans. Quantitative disease resistance (QDR), as any other quantitative trait in plants, can be genetically mapped to understand the genetic architecture. Association mapping using DNA-based markers has been implemented in many crops to dissect quantitative traits. We used an association mapping approach with candidate genes to identify the first genes associated with quantitative resistance to late blight in Solanum tuberosum Group Phureja. Twenty-nine candidate genes were selected from a set of genes that were differentially expressed during the resistance response to late blight in tetraploid European potato cultivars. The 29 genes were amplified and sequenced in 104 accessions of S. tuberosum Group Phureja from Latin America. We identified 238 SNPs in the selected genes and tested them for association with resistance to late blight. The phenotypic data were obtained under field conditions by determining the area under disease progress curve (AUDPC) in two seasons and in two locations. Two genes were associated with QDR to late blight, a potato homolog of thylakoid lumen 15 kDa protein ( StTL15A ) and a stem 28 kDa glycoprotein ( StGP28 ). Key message : A first association mapping experiment was conducted in Solanum tuberosum Group Phureja germplasm, which identified among 29 candidates two genes associated with quantitative resistance to late blight.

Whole-Organism Developmental Expression Profiling Identifies RAB-28 as a Novel Ciliary GTPase Associated with the BBSome and Intraflagellar Transport

PubMed Central

Sanders, Anna A. W. M.; Li, Chunmei; Kennedy, Julie; Cai, Jerry; Scheidel, Noemie; Kennedy, Breandán N.; Morin, Ryan D.; Leroux, Michel R.; Blacque, Oliver E.

2016-01-01

Primary cilia are specialised sensory and developmental signalling devices extending from the surface of most eukaryotic cells. Defects in these organelles cause inherited human disorders (ciliopathies) such as retinitis pigmentosa and Bardet-Biedl syndrome (BBS), frequently affecting many physiological and developmental processes across multiple organs. Cilium formation, maintenance and function depend on intracellular transport systems such as intraflagellar transport (IFT), which is driven by kinesin-2 and IFT-dynein motors and regulated by the Bardet-Biedl syndrome (BBS) cargo-adaptor protein complex, or BBSome. To identify new cilium-associated genes, we employed the nematode C. elegans, where ciliogenesis occurs within a short timespan during late embryogenesis when most sensory neurons differentiate. Using whole-organism RNA-Seq libraries, we discovered a signature expression profile highly enriched for transcripts of known ciliary proteins, including FAM-161 (FAM161A orthologue), CCDC-104 (CCDC104), and RPI-1 (RP1/RP1L1), which we confirm are cilium-localised in worms. From a list of 185 candidate ciliary genes, we uncover orthologues of human MAP9, YAP, CCDC149, and RAB28 as conserved cilium-associated components. Further analyses of C. elegans RAB-28, recently associated with autosomal-recessive cone-rod dystrophy, reveal that this small GTPase is exclusively expressed in ciliated neurons where it dynamically associates with IFT trains. Whereas inactive GDP-bound RAB-28 displays no IFT movement and diffuse localisation, GTP-bound (activated) RAB-28 concentrates at the periciliary membrane in a BBSome-dependent manner and undergoes bidirectional IFT. Functional analyses reveal that whilst cilium structure, sensory function and IFT are seemingly normal in a rab-28 null allele, overexpression of predicted GDP or GTP locked variants of RAB-28 perturbs cilium and sensory pore morphogenesis and function. Collectively, our findings present a new approach for

Whole-Organism Developmental Expression Profiling Identifies RAB-28 as a Novel Ciliary GTPase Associated with the BBSome and Intraflagellar Transport.

PubMed

Jensen, Victor L; Carter, Stephen; Sanders, Anna A W M; Li, Chunmei; Kennedy, Julie; Timbers, Tiffany A; Cai, Jerry; Scheidel, Noemie; Kennedy, Breandán N; Morin, Ryan D; Leroux, Michel R; Blacque, Oliver E

2016-12-01

Primary cilia are specialised sensory and developmental signalling devices extending from the surface of most eukaryotic cells. Defects in these organelles cause inherited human disorders (ciliopathies) such as retinitis pigmentosa and Bardet-Biedl syndrome (BBS), frequently affecting many physiological and developmental processes across multiple organs. Cilium formation, maintenance and function depend on intracellular transport systems such as intraflagellar transport (IFT), which is driven by kinesin-2 and IFT-dynein motors and regulated by the Bardet-Biedl syndrome (BBS) cargo-adaptor protein complex, or BBSome. To identify new cilium-associated genes, we employed the nematode C. elegans, where ciliogenesis occurs within a short timespan during late embryogenesis when most sensory neurons differentiate. Using whole-organism RNA-Seq libraries, we discovered a signature expression profile highly enriched for transcripts of known ciliary proteins, including FAM-161 (FAM161A orthologue), CCDC-104 (CCDC104), and RPI-1 (RP1/RP1L1), which we confirm are cilium-localised in worms. From a list of 185 candidate ciliary genes, we uncover orthologues of human MAP9, YAP, CCDC149, and RAB28 as conserved cilium-associated components. Further analyses of C. elegans RAB-28, recently associated with autosomal-recessive cone-rod dystrophy, reveal that this small GTPase is exclusively expressed in ciliated neurons where it dynamically associates with IFT trains. Whereas inactive GDP-bound RAB-28 displays no IFT movement and diffuse localisation, GTP-bound (activated) RAB-28 concentrates at the periciliary membrane in a BBSome-dependent manner and undergoes bidirectional IFT. Functional analyses reveal that whilst cilium structure, sensory function and IFT are seemingly normal in a rab-28 null allele, overexpression of predicted GDP or GTP locked variants of RAB-28 perturbs cilium and sensory pore morphogenesis and function. Collectively, our findings present a new approach for

Quantitative Glycoproteomic Analysis Identifies Platelet-Induced Increase of Monocyte Adhesion via the Up-Regulation of Very Late Antigen 5.

PubMed

Huang, Jiqing; Kast, Juergen

2015-08-07

Physiological stimuli, such as thrombin, or pathological stimuli, such as lysophosphatidic acid (LPA), activate platelets circulating in blood. Once activated, platelets bind to monocytes via P-selectin-PSGL-1 interactions but also release the stored contents of their granules. These platelet releasates, in addition to direct platelet binding, activate monocytes and facilitate their recruitment to atherosclerotic sites. Consequently, understanding the changes platelet releasates induce in monocyte membrane proteins is critical. We studied the glyco-proteome changes of THP-1 monocytic cells affected by LPA- or thrombin-induced platelet releasates. We employed lectin affinity chromatography combined with filter aided sample preparation to achieve high glyco- and membrane protein and protein sequence coverage. Using stable isotope labeling by amino acids in cell culture, we quantified 1715 proteins, including 852 membrane and 500 glycoproteins, identifying the up-regulation of multiple proteins involved in monocyte extracellular matrix binding and transendothelial migration. Flow cytometry indicated expression changes of integrin α5, integrin β1, PECAM-1, and PSGL-1. The observed increase in monocyte adhesion to fibronectin was determined to be mediated by the up-regulation of very late antigen 5 via a P-selectin-PSGL-1 independent mechanism. This novel aspect could be validated on CD14+ human primary monocytes, highlighting the benefits of the improved enrichment method regarding high membrane protein coverage and reliable quantification.

Spatiotemporal coupling and decoupling of gene transcription with DNA replication origins during embryogenesis in C. elegans

PubMed Central

Pourkarimi, Ehsan; Bellush, James M; Whitehouse, Iestyn

2016-01-01

The primary task of developing embryos is genome replication, yet how DNA replication is integrated with the profound cellular changes that occur through development is largely unknown. Using an approach to map DNA replication at high resolution in C. elegans, we show that replication origins are marked with specific histone modifications that define gene enhancers. We demonstrate that the level of enhancer associated modifications scale with the efficiency at which the origin is utilized. By mapping replication origins at different developmental stages, we show that the positions and activity of origins is largely invariant through embryogenesis. Contrary to expectation, we find that replication origins are specified prior to the broad onset of zygotic transcription, yet when transcription initiates it does so in close proximity to the pre-defined replication origins. Transcription and DNA replication origins are correlated, but the association breaks down when embryonic cell division ceases. Collectively, our data indicate that replication origins are fundamental organizers and regulators of gene activity through embryonic development. DOI: http://dx.doi.org/10.7554/eLife.21728.001 PMID:28009254

Investigating late-onset ADHD: a population cohort investigation.

PubMed

Cooper, Miriam; Hammerton, Gemma; Collishaw, Stephan; Langley, Kate; Thapar, Ajay; Dalsgaard, Søren; Stergiakouli, Evie; Tilling, Kate; Davey Smith, George; Maughan, Barbara; O'Donovan, Michael; Thapar, Anita; Riglin, Lucy

2018-04-23

Adult ADHD has been assumed to be a continuation of childhood-onset ADHD. However, recent studies have identified individuals with ADHD in adulthood who have not had ADHD in childhood. Whether or not these individuals have a 'typical' neurodevelopmental profile is not clear. We tested two explanations for the emergence of apparent late-onset ADHD symptomatology using the ALSPAC epidemiological cohort, by grouping individuals according to their scores on the Strengths and Difficulties Questionnaire (SDQ) hyperactivity subscale at ages 12 and 17 years. First, we tested whether some of those with apparent late-onset ADHD symptoms had been potentially misclassified on the basis of earlier SDQ hyperactivity scores (ages 7, 8 and 9 years) or of subthreshold symptoms at age 12 years. Second, we investigated the possibility that those with 'genuine' late-onset ADHD symptoms had a delayed manifestation of the same liability that underlies childhood-onset symptoms, by investigating whether they had a similar profile of neurodevelopmental impairments (in the domains of autistic symptomatology, language, reading, spelling, executive functioning and IQ) as those with typical childhood-onset ADHD. N = 56/75 (75%) of those with apparent late-onset ADHD had had high ADHD scores at least one point in childhood, suggesting that they may have been misclassified on the basis of their score at age 12 years. The remaining 19 individuals (25%) with genuine late-onset ADHD symptoms did not show a profile of neurodevelopmental impairment typically seen in ADHD, instead showing similar levels of autistic symptoms, language skills, executive functioning ability and IQ to those without ADHD symptoms. The only exceptions were that this group showed reading and spelling problems at age 9 years. Our work suggests that this small number of individuals with genuine late-onset symptoms may not be most appropriately considered as having a typical neurodevelopmental disorder. © 2018 The

Late complications of pelvic irradiation in 16 dogs.

PubMed

Anderson, Christine R; McNiel, Elizabeth A; Gillette, Edward L; Powers, Barbara E; LaRue, Susan M

2002-01-01

When external beam radiation therapy is administered to the pelvis, normal tissues irradiated may include the colon, small intestine, urethra, bladder, bone, and spinal cord. The objectives of this retrospective study were to determine the incidence and severity of late radiation effects following pelvic irradiation in dogs and to identify factors that increase the risk of these effects. Medical records of all dogs treated with curative intent external beam radiation therapy to the pelvic region between 1993 and 1999 were reviewed. Patients with follow-up longer than 9 months or any patient that developed late complications earlier than 9 months were evaluated. Sixteen dogs met criteria for inclusion in this study. All dogs were treated with a 6-MV linear accelerator with bilaterally opposed beams. Diseases treated included transitional cell carcinoma of the bladder, transitional cell carcinoma of the prostate, and anal sac apocrine gland adenocarcinoma. Four dose/fractionation schemes were used: 49.5 Gy in 3.3 Gy fractions, 54 Gy in 3.0 Gy fractions, 54 Gy in 2.7 Gy fractions, and 18 Gy intraoperative radiation therapy followed by 43 Gy external beam radiation therapy in 2.9 Gy fractions. Implantable chemotherapy in the form of an OPLA-Pt sponge was used in six dogs as a radiation potentiator. Colitis was the major late effect following pelvic irradiation, occurring in nine dogs (56%). Colitis was characterized as mild in three dogs, moderate in one dog, and severe in five dogs. Three of the dogs with severe effects suffered gastrointestinal perforation. All dogs with severe late effects received 3 or 3.3 Gy per fraction, and 80% received radiation potentiators. In the seven dogs that received 2.7 Gy or 2.9 Gy per fraction, late effects were classified as none (n = 5), mild colitis (n = 1), and moderate colitis (n = 1). Radiation therapy can be administered to the pelvic region with a minimal risk of late effects to the colon by giving smaller doses per fraction

Chromosome 14 and late-onset familial alzheimer disease (FAD)

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

Schellenberg, G.D.; Anderson, L.; Nemens, E.

1993-09-01

Familial Alzheimer disease (FAD) is genetically heterogeneous. Two loci responsible for early-onset FAD have been identified: the amyloid precursor protein gene on chromosome 21 and the as-yet-unidentified locus on chromosome 14. The genetics of late-onset FAD is unresolved. Maximum-likelihood, affected-pedigree-member (APM), and sib-pair analysis were used, in 49 families with a mean age at onset [>=]60 years, to determine whether the chromosome 14 locus is responsible for late-onset FAD. The markers used were D14S53, D14S43, and D14S52. The LOD score method was used to test for linkage of late-onset FAD to the chromosome 14 markers, under three different models: age-dependentmore » penetrance, an affected-only analysis, and age-dependent penetrance with allowance for possible age-dependent sporadic cases. No evidence for linkage was obtained under any of these conditions for the late-onset kindreds, and strong evidence against linkage (LOD score [>=]2.0) to this region was obtained. Heterogeneity tests of the LOD score results for the combined group of families (early onset, Volga Germans, and late onset) favored the hypothesis of linkage to chromosome 14 with genetic heterogeneity. The positive results are primarily from early-onset families. APM analysis gave significant evidence for linkage of D14S43 and D14S52 to FAD in early-onset kindreds (P<.02). No evidence for linkage was found for the entire late-onset family group. Significant evidence for linkage to D14S52, however, was found for a subgroup of families of intermediate age at onset (mean age at onset [>=]60 years and <70 years). These results indicate that the chromosome 14 locus is not responsible for Alzheimer disease in most late-onset FAD kindreds but could play a role in a subset of these kindreds. 37 refs., 1 fig., 6 tabs.« less

Seed-specific transcription factor HSFA9 links late embryogenesis and early photomorphogenesis

PubMed Central

Prieto-Dapena, Pilar; Almoguera, Concepción; Personat, José-María; Merchan, Francisco

2017-01-01

Abstract HSFA9 is a seed-specific transcription factor that in sunflower (Helianthus annuus) is involved in desiccation tolerance and longevity. Here we show that the constitutive overexpression of HSFA9 in tobacco (Nicotiana tabacum) seedlings attenuated hypocotyl growth under darkness and accelerated the initial photosynthetic development. Plants overexpressing HSFA9 increased accumulation of carotenoids, chlorophyllide, and chlorophyll, and displayed earlier unfolding of the cotyledons. HSFA9 enhanced phytochrome-dependent light responses, as shown by an intensified hypocotyl length reduction after treatments with continuous far-red or red light. This observation indicated the involvement of at least two phytochromes: PHYA and PHYB. Reduced hypocotyl length under darkness did not depend on phytochrome photo-activation; this was inferred from the lack of effect observed using far-red light pulses applied before the dark treatment. HSFA9 increased the expression of genes that activate photomorphogenesis, including PHYA, PHYB, and HY5. HSFA9 might directly upregulate PHYA and indirectly affect PHYB transcription, as suggested by transient expression assays. Converse effects on gene expression, greening, and cotyledon unfolding were observed using a dominant-negative form of HSFA9, which was overexpressed under a seed-specific promoter. This work uncovers a novel transcriptional link, through HSFA9, between seed maturation and early photomorphogenesis. In all, our data suggest that HSFA9 enhances photomorphogenesis via early transcriptional effects that start in seeds under darkness. PMID:28207924

Effect of AgNO3 and BAP on Root as a Novel Explant in Date Palm (Phoenix dactylifera cv. Medjool) Somatic Embryogenesis.

PubMed

Roshanfekrrad, Marjan; Zarghami, Reza; Hassani, Hassan; Zakizadeh, Hedayat; Salari, Ali

2017-01-01

Somatic embryogenesis techniques are used for cloning a wide range of varieties of date palms around the world. The aim of the present study was to develop an efficient method with the lowest cost and the greatest potential to obtain in vitro plantlets of date palm cv. Medjool. Also, produce embryogenic callus and somatic embryos without using 2,4-dichlorophenoxyacetic acid (2,4-D). In this study, produced plantlets through somatic embryogenesis were used in vitro roots as explant cultured on Murashige and Skoog (MS) media containing three level of Silver Nitrate (AgNO3) (0, 3 and 6 mg L-1) plus two level of 6-benzylaminopurine (BAP) (0 and 2 mg L-1) plus 0.1 mg L-1 1-naphthylacetic acid (NAA) for callus induction. After 12 weeks of culture, callus induction and after 16 weeks, production of embryogenic callus and embryos were occurred from root explants. According to the results, medium containing 2 mg L-1 BAP and 3 mg L-1 silver nitrate+0.1 mg L-1 NAA showed the highest amount of embryogenic callus fresh weight (1.38 g). This treatment also cause the highest number and length of embryos by production of 90.04 embryogenic callus with length of 11.18 mm. On the other hand, shoots were appeared from germinated embryos and white roots began to appear within 8 weeks. Medium contains 3 mg L-1 BAP and 0.1 mg L-1 NAA with average of 12.27 cm shoot length and 15.48 cm root length was the best. Control treatment had the lowest average shoot (3.71 cm) and root (5.03 cm) length. This study showed that certain concentration of silver nitrate and BAP has stimulating effect on growth of produced embryonic callus from root segments of Medjool cultivar of date palm.

Late hematologic toxicity following treatment of rattlesnake envenomation with crotalidae polyvalent immune Fab antivenom.

PubMed

Ruha, Anne-Michelle; Curry, Steven C; Albrecht, Clay; Riley, Brad; Pizon, Anthony

2011-01-01

North American rattlesnake envenomations commonly produce defibrination, coagulopathy and/or thrombocytopenia, which may be reversed following treatment with Crotalidae Polyvalent Immune Fab Ovine (FabAV). Despite initial resolution with FabAV, late onset or recurrence of venom-induced hematologic effects may occur. Time at which onset of late hematotoxicity may first be detected is unknown. The purpose of this study was to identify the incidence and time of onset of recurrent or new late hypofibrinogenemia, coagulopathy, or thrombocytopenia in a cohort of rattlesnake envenomation patients seen in outpatient follow-up after treatment with FabAV, and to report hematologic outcomes in these patients. Review of 66 charts of patients with rattlesnake envenomation who were treated with FabAV, and subsequently had outpatient follow-up evaluation at least 48 h after last FabAV, was performed. Demographic information, rattlesnake and bite characteristics, dose and timing of antivenom administration, adverse events, in-patient laboratory values, length of hospital stay, and follow-up laboratory values were collected. The primary outcome parameters were recurrent or delayed onset coagulopathy, hypofibrinogenemia, or thrombocytopenia identified no sooner than 48 h after last dose of FabAV. Prior to control of the envenomation with FabAV, 42 patients (63.6%) experienced hematologic toxicity. At follow-up, 21 patients (32%) were found to have late coagulopathy, hypofibrinogenemia, or thrombocytopenia. Of twenty-three patients (35%) with more than one follow-up visit, fifteen had normal laboratory findings at the first follow-up visit. Five of these 15 patients (8% of total study group; 33% of this subgroup) with normal hematologic studies at first follow-up exhibited late hematologic toxicity at second follow-up. Severe late hematologic toxicity developed in five of 66 (8%) patients. One patient was retreated with FabAV for late severe thrombocytopenia. Recurrent and delayed

Lethality in PARP-1/Ku80 double mutant mice reveals physiologicalsynergy during early embryogenesis

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

Henrie, Melinda S.; Kurimasa, Akihiro; Burma, Sandeep

2002-09-24

Ku is an abundant heterodimeric nuclear protein, consisting of 70-kDa and 86-kDa tightly associated subunits that comprise the DNA binding component of DNA-dependent protein kinase. Poly(ADP)ribose polymerase-1 (PARP-1) is a 113-kDa protein that catalyzes the synthesis of poly(ADP-ribose) on target proteins. Both Ku and PARP-1 recognize and bind to DNA ends. Ku functions in the non-homologous end joining (NHEJ) repair pathway whereas PARP-1 functions in the single strand break repair and base excision repair (BER) pathways. Recent studies have revealed that PARP-1 and Ku80 interact in vitro. To determine whether the association of PARP-1 and Ku80 has any physiological significancemore » or synergistic function in vivo, mice lacking both PARP-1 and Ku80 were generated. The resulting offspring died during embryonic development displaying abnormalities around the gastrulation stage. In addition, PARP-1-/-Ku80-/- cultured blastocysts had an increased level of apoptosis. These data suggest that the functions of both Ku80 and PARP-1 are essential for normal embryogenesis and that a loss of genomic integrity leading to cell death through apoptosis is likely the cause of the embryonic lethality observed in these mice.« less

Acid stress mediated adaptive divergence in ion channel function during embryogenesis in Rana arvalis

PubMed Central

Shu, Longfei; Laurila, Anssi; Räsänen, Katja

2015-01-01

Ion channels and pumps are responsible for ion flux in cells, and are key mechanisms mediating cellular function. Many environmental stressors, such as salinity and acidification, are known to severely disrupt ionic balance of organisms thereby challenging fitness of natural populations. Although ion channels can have several vital functions during early life-stages (e.g. embryogenesis), it is currently not known i) how developing embryos maintain proper intracellular conditions when exposed to environmental stress and ii) to what extent environmental stress can drive intra-specific divergence in ion channels. Here we studied the moor frog, Rana arvalis, from three divergent populations to investigate the role of different ion channels and pumps for embryonic survival under acid stress (pH 4 vs 7.5) and whether populations adapted to contrasting acidities differ in the relative role of different ion channel/pumps. We found that ion channels that mediate Ca2+ influx are essential for embryonic survival under acidic pH, and, intriguingly, that populations differ in calcium channel function. Our results suggest that adaptive divergence in embryonic acid stress tolerance of amphibians may in part be mediated by Ca2+ balance. We suggest that ion flux may mediate adaptive divergence of natural populations at early life-stages in the face of environmental stress. PMID:26381453

Function and regulation of heat shock factor 2 during mouse embryogenesis

PubMed Central

Rallu, M.; Loones, Mt.; Lallemand, Y.; Morimoto, R.; Morange, M.; Mezger, V.

1997-01-01

The spontaneous expression of heat shock genes during development is well documented in many animal species, but the mechanisms responsible for this developmental regulation are only poorly understood. In vertebrates, additional heat shock transcription factors, distinct from the heat shock factor 1 (HSF1) involved in the stress response, were suggested to be involved in this developmental control. In particular, the mouse HSF2 has been found to be active in testis and during preimplantation development. However, the role of HSF2 and its mechanism of activation have remained elusive due to the paucity of data on its expression during development. In this study, we have examined HSF2 expression during the postimplantation phase of mouse development. Our data show a developmental regulation of HSF2, which is expressed at least until 15.5 days of embryogenesis. It becomes restricted to the central nervous system during the second half of gestation. It is expressed in the ventricular layer of the neural tube which contains mitotically active cells but not in postmitotic neurons. Parallel results were obtained for mRNA, protein, and activity levels, demonstrating that the main level of control was transcriptional. The detailed analysis of the activity of a luciferase reporter gene under the control of the hsp70.1 promoter, as well as the description of the protein expression patterns of the major heat shock proteins in the central nervous system, show that HSF2 and heat shock protein expression domains do not coincide. This result suggests that HFS2 might be involved in other regulatory developmental pathways and paves the way to new functional approaches. PMID:9122205

Exploring Career Success of Late Bloomers from the TVET Background

ERIC Educational Resources Information Center

Omar, Zoharah; Krauss, Steven Eric; Sail, Rahim M.; Ismail, Ismi Arif

2011-01-01

Purpose: The purpose of this paper is to explore objective and subjective career success and to identify factors contributing to career success among a sample of technical and vocational education and training (TVET) "late bloomers" working in Malaysia. Design/methodology/approach: Incorporating a mixed method design, the authors…

Electrocardiographic Biomarkers for Detection of Drug-Induced Late Sodium Current Block

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

Vicente, Jose; Johannesen, Lars; Hosseini, Meisam

Drugs that prolong the heart rate corrected QT interval (QTc) on the electrocardiogram (ECG) by blocking the hERG potassium channel and also block inward currents (late sodium or L-type calcium) are not associated with torsade de pointes (e.g. ranolazine and verapamil). Furthermore, identifying ECG signs of late sodium current block could aid in the determination of proarrhythmic risk for new drugs. A new cardiac safety paradigm for drug development (the "CiPA" initiative) will involve the preclinical assessment of multiple human cardiac ion channels and ECG biomarkers are needed to determine if there are unexpected ion channel effects in humans.

Electrocardiographic Biomarkers for Detection of Drug-Induced Late Sodium Current Block

DOE PAGES

Vicente, Jose; Johannesen, Lars; Hosseini, Meisam; ...

2016-12-30

Drugs that prolong the heart rate corrected QT interval (QTc) on the electrocardiogram (ECG) by blocking the hERG potassium channel and also block inward currents (late sodium or L-type calcium) are not associated with torsade de pointes (e.g. ranolazine and verapamil). Furthermore, identifying ECG signs of late sodium current block could aid in the determination of proarrhythmic risk for new drugs. A new cardiac safety paradigm for drug development (the "CiPA" initiative) will involve the preclinical assessment of multiple human cardiac ion channels and ECG biomarkers are needed to determine if there are unexpected ion channel effects in humans.

Medically significant late bleeding after treated crotaline envenomation: a systematic review.

PubMed

Lavonas, Eric J; Khatri, Vaishali; Daugherty, Claire; Bucher-Bartelson, Becki; King, Thomas; Dart, Richard C

2014-01-01

We estimate the proportion of patients with crotaline snake envenomation who are treated with Crotalidae polyvalent immune Fab (ovine) antivenom and who develop medically significant late bleeding. We performed a systematic review of all published cohort studies of North American crotaline snake envenomation patients treated with Fab antivenom. We searched PubMed, Ovid MEDLINE, and EMBASE from January 1, 1997, to April 30, 2012. Data were extracted by 2 trained researchers. Late bleeding was defined as bleeding that began or recurred after initial control of the envenomation syndrome. Medically significant late bleeding was defined a priori as late bleeding treated with RBC transfusion, vasoactive drug infusion, surgery, or rehospitalization or associated with a hemoglobin decrease of greater than or equal to 3 g/dL, hematocrit decrease of greater than or equal to 8%, disability, or death. Summary incidence and 95% confidence intervals (CIs) were calculated with a random-effects Poisson regression model. Nineteen unique cohort studies were identified. Four studies collected data prospectively, and in 9 studies, patients were followed actively after hospital discharge. A total of 1,017 subjects were enrolled in these cohort studies. Late bleeding was reported in 9 subjects (0.9%; 95% CI 0.4% to 2.2%), of whom 5 subjects (0.5%; 95% CI 0.1% to 1.7%) had medically significant late bleeding. Three patients received RBC transfusion; no deaths or permanent sequelae were reported. Estimates of risk may be affected by underreporting. Medically significant late bleeding appears to be uncommon in snakebite victims treated with Fab antivenom. Copyright © 2013 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

School Mobility during Childhood Predicts Psychotic Symptoms in Late Adolescence

ERIC Educational Resources Information Center

Winsper, Catherine; Wolke, Dieter; Bryson, Alex; Thompson, Andrew; Singh, Swaran P.

2016-01-01

Background: Recently, school mobility was identified as a risk factor for psychotic symptoms in early adolescence. The extent to which this risk continues into late adolescence and the trajectories via which this risk manifests remain unexplored. Methods: Psychotic symptoms in 4,720 adolescents aged 18 were ascertained by trained psychologists…

Late-onset offending: fact or fiction.

PubMed

Wiecko, Filip M

2014-01-01

This research focuses on a detailed exploration of late-onset offending. Using the National Youth Survey, this work seeks to answer three questions. First, is late-onset offending a real phenomenon? Second, if late onset does exist, is the evidence for it conditioned by how we define crime and delinquency? Finally, is late-onset offending an artifact of measurement methodology? Most literature evidencing late onset relies on official police contact and arrest data. Propensity or control theories in general posit that late onset should not exist. Propensity, namely self-control, should be instilled early in life and if absent, results in early initiation into crime and delinquency. Research in developmental psychology seems to support this notion. The findings from this study indicate that late-onset offending is almost nonexistent when self-reported measures are used leading one to conclude that contemporary evidence for late-onset is heavily conditioned by how we measure crime and delinquency. A comprehensive discussion includes future directions for research, and implications for theory development and methodology.

Early and late menarche are associated with oligomenorrhea and predict metabolic syndrome 26 years later.

PubMed

Glueck, Charles J; Morrison, John A; Wang, Ping; Woo, Jessica G

2013-11-01

We determined whether simple, clinical information on late and early menarche could help identify adult women with metabolic syndrome (MetS) and oligomenorrhea. We carried out a 26-year prospective follow-up of 272 suburban schoolgirls from ages 5-22 to 30-46. Early menarche (≤10 years, 5.2% of girls) and late menarche (≥16 years, 6.7% of girls) were both associated with oligomenorrhea (≥42 days) in adulthood, 29% and 11%, vs. 5% for normal menarche (11-15 years), p=.004. Early menarche was characterized by high childhood BMI (LS mean±SE: 21.2 ±1.0 kg/m2) and by high childhood and adult MetS (15%, 36%). Girls with late menarche had the lowest childhood BMI (18.1±1.0), no childhood MetS, and the highest adult MetS (47%). Increasing age at menarche was associated with uniformly decreasing childhood BMI and MetS, but with a U-shaped pattern of BMI (p = .05), MetS (p=.008), and oligomenorrhea (p=.02) in adulthood. Change to MetS from median ages 13 to 38 was associated with early-late menarche (OR=3.11, 95% CI 1.37-7.07, p=.007). MetS in adulthood was associated with childhood MetS (OR=8.03, 95% CI 2.57-25.08, p=.0003) and with early-late menarche (OR =3.43, 95% CI 1.44-8.15, p=.005). Menarche age had a curvilinear ('U' shaped) relationship with MetS and oligomenorrhea in adulthood. Late menarche and early menarche are risk factors for adult oligomenorrhea, MetS, and cardiometabolic abnormalities. Girls with early (≤ age 10) and with late menarche (≥ 16) represent a group at high risk for adult cardiometabolic abnormalities and oligomenorrhea that is easily identifiable by physicians. © 2013.

Acyl-CoA-Binding Protein ACBP1 Modulates Sterol Synthesis during Embryogenesis.

PubMed

Lung, Shiu-Cheung; Liao, Pan; Yeung, Edward C; Hsiao, An-Shan; Xue, Yan; Chye, Mee-Len

2017-07-01

Fatty acids (FAs) and sterols are primary metabolites that exert interrelated functions as structural and signaling lipids. Despite their common syntheses from acetyl-coenzyme A, homeostatic cross talk remains enigmatic. Six Arabidopsis ( Arabidopsis thaliana ) acyl-coenzyme A-binding proteins (ACBPs) are involved in FA metabolism. ACBP1 interacts with PHOSPHOLIPASE Dα1 and regulates phospholipid composition. Here, its specific role in the negative modulation of sterol synthesis during embryogenesis is reported. ACBP1, likely in a liganded state, interacts with STEROL C4-METHYL OXIDASE1-1 (SMO1-1), a rate-limiting enzyme in the sterol pathway. Proembryo abortion in the double mutant indicated that the ACBP1-SMO1-1 interaction is synthetic lethal, corroborating with their strong promoter activities in developing ovules. Gas chromatography-mass spectrometry revealed quantitative and compositional changes in FAs and sterols upon overexpression or mutation of ACBP1 and/or SMO1-1 Aberrant levels of these metabolites may account for the downstream defect in lipid signaling. GLABRA2 ( GL2 ), encoding a phospholipid/sterol-binding homeodomain transcription factor, was up-regulated in developing seeds of acbp1 , smo1-1 , and ACBP1 +/- smo1-1 in comparison with the wild type. Consistent with the corresponding transcriptional alteration of GL2 targets, high-oil, low-mucilage phenotypes of gl2 were phenocopied in ACBP1 +/- smo1-1 Thus, ACBP1 appears to modulate the metabolism of two important lipid classes (FAs and sterols) influencing cellular signaling. © 2017 American Society of Plant Biologists. All Rights Reserved.

Precursors and Correlates of Anxiety Trajectories from Late Childhood to Late Adolescence

ERIC Educational Resources Information Center

Letcher, Primrose; Sanson, Ann; Smart, Diana; Toumbourou, John W.

2012-01-01

The present research employed a prospective, multi-informant design to examine precursors and correlates of differing anxiety profiles from late childhood to late adolescence. The sample consisted of 626 boys and 667 girls who are participants in the Australian Temperament Project, a large, longitudinal, community-based study that has followed…

Suicides in Late Life

PubMed Central

Van Orden, Kimberly; Conwell, Yeates

2011-01-01

Suicide in late life is an enormous public health problem that will likely increase in severity as adults of the baby boom generation age. Data from psychological autopsy studies supplemented with recent studies of suicidal ideation and attempts point to a consistent set of risk factors for the spectrum of suicidal behaviors in late life (suicide ideation, attempts, and deaths). Clinicians should be vigilant for psychiatric illness (especially depression), physical illness, pain, functional impairment, and social disconnectedness. Recent advances in late-life suicide prevention have in common collaborative, multifaceted intervention designs. We suggest that one mechanism shared by all preventive interventions shown to reduce the incidence of late-life suicide is the promotion of connectedness. For the clinician working with older adults, our recommendation is to not only consider risk factors, such as depression, and implement appropriate treatments but to enhance social connectedness as well. PMID:21369952

Use of ultrasonography to identify late-stage maturity in rainbow trout Oncorhynchus mykiss

USDA-ARS?s Scientific Manuscript database

Morphometric measurements by ultrasonography has been used to determine gonad and follicle size in many species of fish for purposes of identifying sex and estimating stage of maturation. We have been using a portable ultrasound system (SonoSite MicroMaxx, L25e/13-6 MHz transducer) to identify fem...

Genetic and Hormonal Regulation of Chlorophyll Degradation during Maturation of Seeds with Green Embryos

PubMed Central

Dolgikh, Elena; Vikhnina, Maria; Frolov, Andrej

2017-01-01

The embryos of some angiosperms (usually referred to as chloroembryos) contain chlorophylls during the whole period of embryogenesis. Developing embryos have photochemically active chloroplasts and are able to produce assimilates, further converted in reserve biopolymers, whereas at the late steps of embryogenesis, seeds undergo dehydration, degradation of chlorophylls, transformation of chloroplast in storage plastids, and enter the dormancy period. However, in some seeds, the process of chlorophyll degradation remains incomplete. These residual chlorophylls compromise the quality of seed material in terms of viability, nutritional value, and shelf life, and represent a serious challenge for breeders and farmers. The mechanisms of chlorophyll degradation during seed maturation are still not completely understood, and only during the recent decades the main pathways and corresponding enzymes could be characterized. Among the identified players, the enzymes of pheophorbide a oxygenase pathway and the proteins encoded by STAY GREEN (SGR) genes are the principle ones. On the biochemical level, abscisic acid (ABA) is the main regulator of seed chlorophyll degradation, mediating activity of corresponding catabolic enzymes on the transcriptional level. In general, a deep insight in the mechanisms of chlorophyll degradation is required to develop the approaches for production of chlorophyll-free high quality seeds. PMID:28926960

Mutations in the Drosophila neuroglian cell adhesion molecule affect motor neuron pathfinding and peripheral nervous system patterning.

PubMed

Hall, S G; Bieber, A J

1997-03-01

We have identified and characterized three embryonic lethal mutations that alter or abolish expression of Drosophila Neuroglian and have used these mutations to analyze Neuroglian function during development. Neuroglian is a member of the immunoglobulin superfamily. It is expressed by a variety of cell types during embryonic development, including expression on motoneurons and the muscle cells that they innervate. Examination of the nervous systems of neuroglian mutant embryos reveals that motoneurons have altered pathfinding trajectories. Additionally, the sensory cell bodies of the peripheral nervous system display altered morphology and patterning. Using a temperature-sensitive mutation, the phenocritical period for Neuroglian function was determined to occur during late embryogenesis, an interval which coincides with the period during which neuromuscular connections and the peripheral nervous system pattern are established.

The influence of genetic variation on late toxicities in childhood cancer survivors: A review.

PubMed

Clemens, E; van der Kooi, A L F; Broer, L; van Dulmen-den Broeder, E; Visscher, H; Kremer, L; Tissing, W; Loonen, J; Ronckers, C M; Pluijm, S M F; Neggers, S J C M M; Zolk, O; Langer, T; Zehnhoff-Dinnesen, A Am; Wilson, C L; Hudson, M M; Carleton, B; Laven, J S E; Uitterlinden, A G; van den Heuvel-Eibrink, M M

2018-06-01

The variability in late toxicities among childhood cancer survivors (CCS) is only partially explained by treatment and baseline patient characteristics. Inter-individual variability in the association between treatment exposure and risk of late toxicity suggests that genetic variation possibly modifies this association. We reviewed the available literature on genetic susceptibility of late toxicity after childhood cancer treatment related to components of metabolic syndrome, bone mineral density, gonadal impairment and hearing impairment. A systematic literature search was performed, using Embase, Cochrane Library, Google Scholar, MEDLINE, and Web of Science databases. Eligible publications included all English language reports of candidate gene studies and genome wide association studies (GWAS) that aimed to identify genetic risk factors associated with the four late toxicities, defined as toxicity present after end of treatment. Twenty-seven articles were identified, including 26 candidate gene studies: metabolic syndrome (n = 6); BMD (n = 6); gonadal impairment (n = 2); hearing impairment (n = 12) and one GWAS (metabolic syndrome). Eighty percent of the genetic studies on late toxicity after childhood cancer had relatively small sample sizes (n < 200), leading to insufficient power, and lacked adjustment for multiple comparisons. Only four (4/26 = 15%) candidate gene studies had their findings validated in independent replication cohorts as part of their own report. Genetic susceptibility associations are not consistent or not replicated and therefore, currently no evidence-based recommendations can be made for hearing impairment, gonadal impairment, bone mineral density impairment and metabolic syndrome in CCS. To advance knowledge related to genetic variation influencing late toxicities among CCS, future studies need adequate power, independent cohorts for replication, harmonization of disease outcomes and sample collections, and

Serial population extinctions in a small mammal indicate Late Pleistocene ecosystem instability

PubMed Central

Brace, Selina; Palkopoulou, Eleftheria; Dalén, Love; Lister, Adrian M.; Miller, Rebecca; Otte, Marcel; Germonpré, Mietje; Blockley, Simon P. E.; Stewart, John R.; Barnes, Ian

2012-01-01

The Late Pleistocene global extinction of many terrestrial mammal species has been a subject of intensive scientific study for over a century, yet the relative contributions of environmental changes and the global expansion of humans remain unresolved. A defining component of these extinctions is a bias toward large species, with the majority of small-mammal taxa apparently surviving into the present. Here, we investigate the population-level history of a key tundra-specialist small mammal, the collared lemming (Dicrostonyx torquatus), to explore whether events during the Late Pleistocene had a discernible effect beyond the large mammal fauna. Using ancient DNA techniques to sample across three sites in North-West Europe, we observe a dramatic reduction in genetic diversity in this species over the last 50,000 y. We further identify a series of extinction-recolonization events, indicating a previously unrecognized instability in Late Pleistocene small-mammal populations, which we link with climatic fluctuations. Our results reveal climate-associated, repeated regional extinctions in a keystone prey species across the Late Pleistocene, a pattern likely to have had an impact on the wider steppe-tundra community, and one that is concordant with environmental change as a major force in structuring Late Pleistocene biodiversity. PMID:23185018

Early and Late Recurrent Epistaxis Admissions: Patterns of Incidence and Risk Factors.

PubMed

Cohen, Oded; Shoffel-Havakuk, Hagit; Warman, Meir; Tzelnick, Sharon; Haimovich, Yaara; Kohlberg, Gavriel D; Halperin, Doron; Lahav, Yonatan

2017-09-01

Objective Epistaxis is a common complaint, yet few studies have focused on the incidence and risk factors of recurrent epistaxis. Our objective was to determine the patterns of incidence and risk factors for recurrent epistaxis admission (REA). Study Design Case series with chart review. Settings Single academic center. Subjects and Methods The medical records of patients admitted for epistaxis between 1999 and 2015 were reviewed. The follow-up period was defined as 3 years following initial admission. REAs were categorized as early (30 days) and late (31 days to 3 years) following initial admission. Logistic regression was used to identify potential predictors of REAs. Results A total of 653 patients were included. Eighty-six patients (14%) had REAs: 48 (7.5%) early and 38 (6.5%) late. Nonlinear incidence curve was demonstrated for both early and late REAs. Based on logistic regression, prior nasal surgery and anemia were independent risk factors for early REAs. According to multivariate analysis, thrombocytopenia was significantly associated with late REAs. Conclusion Early and late REAs demonstrate different risk predictors. Knowledge of such risk factors may help in risk stratification for this selected group of patients. All patients at risk should be advised on possible preventive measures. Patients at risk for early REA may benefit from a more proactive approach.

Why do pregnant women present late for their first antenatal care consultation in Cameroon?

PubMed

Tolefac, Paul Nkemtendong; Halle-Ekane, Gregory Edie; Agbor, Valirie Ndip; Sama, Carlson Barbila; Ngwasiri, Calypse; Tebeu, Pierre Marie

2017-01-01

Early initiation of antenatal care visits is an essential component of services to improving maternal and new born health. The Cameroonian Demographic and Health Survey conducted in 2011 indicated that only 34% of pregnant women start antenatal care in the first trimester. However, detailed study to identify factors associated with late initiation of care has not been conducted in Cameroon. The aim of this study was to assess the prevalence of late booking first ANC visit amongst attendance of first ANC and the determinants of late first ANC in Douala general hospital. It was a cross sectional analytic study over the period of 5 months in Douala general hospital. The study subjects were pregnant women visiting the facilities for the first time during the index pregnancy. Data were collected using pre-tested questionnaire. Logistic regression analysis was done to identify factors associated with late first ANC with the level of significance set at 0.05. A total of 293 women participated in the study; 129 (44.0%) of them came for their first ANC visit late, after 12 weeks of gestation. Most common reasons for coming late for first ANC were financial constraints (34.5%, 45) and long distance to the hospital (34.5%, 45). Factors associated with late start of first ANC after logistic regression were: family size greater than 4 (OR = 2, 95% CI = 1.25-3.19, p value = 0.004), long distance to the hospital (OR = 1.84, 95% CI = 1.1-3.07, p value = 0.02) and low monthly income level less than 200US dollars (OR = 3.2, 95% CI = 1.33-3.54, p value = 0.002). About half of pregnant women do not start ANC early in the first trimester largely due to large family size, low monthly income and long distance to the hospital.

Expression of phosphatidylcholine biosynthetic enzymes during early embryogenesis in the amphibian Bufo arenarum.

PubMed

Fernández-Bussy, Rodrigo; Mouguelar, Valeria; Banchio, Claudia; Coux, Gabriela

2015-04-01

In the principal route of phosphatidylcholine (PC) synthesis the regulatory steps are catalysed by CTP:phosphocholine cytidylyltransferase (CCT) and choline kinase (CK). Knock-out mice in Pcyt1a (CCT gene) and Chka1 (CK gene) resulted in preimplantation embryonic lethality, demonstrating the essential role of this pathway. However, there is still a lack of detailed CCT and CK expression analysis during development. The aim of the current work was to study the expression during early development of both enzymes in the external-fertilization vertebrate Bufo arenarum. Reverse transcription polymerase chain reaction (RT-PCR) and western blot confirmed their presence in unfertilized eggs. Analysis performed in total extracts from staged embryos showed constant protein levels of both enzymes until the 32-cell stage: then they decreased, reaching a minimum in the gastrula before starting to recover. CTP:phosphocholine cytidylyltransferase is an amphitropic enzyme that inter-converts between cytosolic inactive and membrane-bound active forms. Immunoblot analysis demonstrated that the cytosolic:total CCT protein ratio does not change throughout embryogenesis, suggesting a progressive decline of CCT activity in early development. However, PC (and phosphatidylethanolamine) content per egg/embryo remained constant throughout the stages analysed. In conclusion, the current data for B. arenarum suggest that net synthesis of PC mediated by CCT and CK is not required in early development and that supplies for membrane biosynthesis are fulfilled by lipids already present in the egg/embryo reservoirs.

Lifetime hormonal factors may predict late-life depression in women

PubMed Central

Ryan, Joanne; Carrière, Isabelle; Scali, Jacqueline; Ritchie, Karen; Ancelin, Marie-Laure

2008-01-01

Background Fluctuating hormone levels are known to influence a woman’s mood and well-being. This study aimed to determine whether lifetime hormonal markers are associated with late-life depression symptoms among elderly community-dwelling women. Method Detailed reproductive histories of 1013 women aged 65 years and over were obtained using questionnaires and depressive symptoms were assessed using the Centre for Epidemiological Studies Depression Scale. Multivariate logistic regression models were generated to determine whether any lifetime endogenous or exogenous hormonal factors were associated with late-life depression. Results The prevalence of depressive symptoms was 17%. Age at menopause was associated with depressive symptoms, but only among women with a lower education level. For these women, an earlier age at menopause increased their risk of late-life depression (linear effect, OR=0.95, 95%CI: 0.91–0.99). The odds of late-life depression were also increased for women who were past (OR=1.6, 95%CI: 1.1–2.5), but not current hormonal replacement users. On the other hand, long-term oral contraceptive use (≥10 years) was protective against depression (OR=0.3, 95%CI: 0.1–0.9). These associations remained significant even after extensive adjustment for a range of potential confounding factors, including socio-demographic factors, mental and physical incapacities, antidepressant use and past depression. The other factors examined, including age at first menses, parity, age at childbirth and surgical menopause, were not associated with late-life depressive symptoms. Conclusions Lifetime hormonal factors that are significantly associated with depression symptoms in later life have been identified. Further work is needed to determine how potential hormonal interventions could be used in the treatment of late-life depression in certain sub-groups of women. PMID:18533067

Late-life factors associated with healthy aging in older men.

PubMed

Bell, Christina L; Chen, Randi; Masaki, Kamal; Yee, Priscilla; He, Qimei; Grove, John; Donlon, Timothy; Curb, J David; Willcox, D Craig; Poon, Leonard W; Willcox, Bradley J

2014-05-01

To identify potentially modifiable late-life biological, lifestyle, and sociodemographic factors associated with overall and healthy survival to age 85. Prospective longitudinal cohort study with 21 years of follow-up (1991-2012). Hawaii Lifespan Study. American men of Japanese ancestry (mean age 75.7, range 71-82) without baseline major clinical morbidity and functional impairments (N = 1,292). Overall survival and healthy survival (free from six major chronic diseases and without physical or cognitive impairment) to age 85. Factors were measured at late-life baseline examinations (1991-1993). Of 1,292 participants, 1,000 (77%) survived to 85 (34% healthy) and 309 (24%) to 95 (<1% healthy). Late-life factors associated with survival and healthy survival included biological (body mass index, ankle-brachial index, cognitive score, blood pressure, inflammatory markers), lifestyle (smoking, alcohol use, physical activity), and sociodemographic factors (education, marital status). Cumulative late-life baseline risk factor models demonstrated that age-standardized (at 70) probability of survival to 95 ranged from 27% (no factors) to 7% (≥ 5 factors); probability of survival to 100 ranged from 4% (no factors) to 0.1% (≥ 5 factors). Age-standardized (at 70) probability of healthy survival to 90 ranged from 4% (no factors) to 0.01% (≥ 5 factors). There were nine healthy survivors at 95 and one healthy survivor at 100. Several potentially modifiable risk factors in men in late life (mean age 75.7) were associated with markedly greater probability of subsequent healthy survival and longevity. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

Late extensor pollicis longus rupture following plate fixation in Galeazzi fracture dislocation

PubMed Central

Sabat, Dhananjaya; Dabas, Vineet; Dhal, Anil

2014-01-01

Late rupture of extensor pollicis longus (EPL) tendon after Galeazzi fracture dislocation fixation is an unknown entity though it is a well-established complication following distal radius fractures. We report the case of a 55-year old male who presented with late EPL tendon rupture 4 months following internal fixation of Galeazzi fracture dislocation with a Locking Compression Plate (LCP). He was managed with extensor indicis proprius (EIP) transfer to restore thumb extension. At 4 years followup, functional result of the transfer was good. We identify possible pitfalls with this particular patient and discuss how to avoid them in future. PMID:25143650

Radiation-induced lymphocyte apoptosis to predict radiation therapy late toxicity in prostate cancer patients.

PubMed

Schnarr, Kara; Boreham, Douglas; Sathya, Jinka; Julian, Jim; Dayes, Ian S

2009-08-01

To examine a potential correlation between the in vitro apoptotic response of lymphocytes to radiation and the risk of developing late gastrointestinal (GI)/genitourinary (GU) toxicity from radiotherapy for prostate cancer. Prostate cancer patients formerly enrolled in a randomized study were tested for radiosensitivity by using a radiation-induced lymphocyte apoptosis assay. Apoptosis was measured using flow cytometry-based Annexin-FITC/7AAD and DiOC(6)/7AAD assays in subpopulations of lymphocytes (total lymphocytes, CD4+, CD8+ and CD4-/CD8-) after exposure to an in vitro dose of 0, 2, 4, or 8 Gy. Patients with late toxicity after radiotherapy showed lower lymphocyte apoptotic responses to 8 Gy than patients who had not developed late toxicity (p = 0.01). All patients with late toxicity had apoptosis levels that were at or below the group mean. The negative predictive value in both apoptosis assays ranged from 95% to 100%, with sensitivity values of 83% to 100%. Apoptosis at lower dose points and in lymphocyte subpopulations had a weaker correlation with the occurrence of late toxicity. Lymphocyte apoptosis after 8 Gy of radiation has the potential to predict which patients will be spared late toxicity after radiation therapy. Further research should be performed to identify the specific subset of lymphocytes that correlates with late toxicity, followed by a corresponding prospective study.

Flank vents and graben as indicators of Late Amazonian volcanotectonic activity on Olympus Mons

NASA Astrophysics Data System (ADS)

Peters, S. I.; Christensen, P. R.

2017-03-01

Previous studies have focused on large-scale features on Olympus Mons, such as its flank terraces, the summit caldera complex, and the basal escarpment and aureole deposits. Here we identify and characterize previously unrecognized and unmapped small scale features to help further understand the volcanotectonic evolution of this enormous volcano. Using Context Camera, High Resolution Imaging Science Experiment, Thermal Emission Imaging System, High Resolution Stereo Camera Digital Terrain Model, and Mars Orbiter Laser Altimeter data, we identified and characterized the morphology and distribution of 60 flank vents and 84 grabens on Olympus Mons. We find that effusive eruptions have dominated volcanic activity on Olympus Mons in the Late Amazonian. Explosive eruptions were rare, implying volatile-poor magmas and/or a lack of magma-water interactions during the Late Amazonian. The distribution of flank vents suggests dike propagation of hundreds of kilometers and shallow magma storage. Small grabens, not previously observed in lower-resolution data, occur primarily on the lower flanks of Olympus Mons and indicate late-stage extensional tectonism. Based on superposition relationships, we have concluded two stages of development for Olympus Mons during the Late Amazonian: (1) primarily effusive resurfacing and formation of flank vents followed by (2) waning effusive volcanism and graben formation and/or reactivation. This developmental sequence resembles that proposed for Ascraeus Mons and other large Martian shields, suggesting a similar geologic evolution for these volcanoes.

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.

Isozyme modifications and plant regeneration through somatic embryogenesis in sweet potato (Ipomoea batatas (L.) Lam.).

PubMed

Cavalcante Alves, J M; Sihachakr, D; Allot, M; Tizroutine, S; Mussio, I; Servaes, A; Ducreux, G

1994-05-01

The potential of somatic embryogenesis was evaluated for 10 cultivars of sweet potato through extensive embryogenic response and isozyme analysis. Embryogenic callus was induced by incubating lateral buds on Murashige and Skoog medium containing 10 μM 2,4-dichlorophenoxyacetic acid for 6-8 weeks. The frequency of embryogenic response was low, and varied with genotypes, ranging from 0 to 17%. Embryo to plantlet formation could be enhanced by the use of the combination of 2,4-dichlorophenoxyacetic acid with kinetin, both used at 0.01 μM. Embryogenic callus with its potential of plantlet formation has constantly been maintained for over two years. However, after several subcultures, 0.5 to 12% of embryogenic callus reverted irreversibly into friable fast-growing non-embryogenic callus whose ability to regenerate shoots was then definitively lost. The isozymes of esterase, peroxidase, glutamate oxaloacetate transaminase and acid phosphatase investigated in this study were found appropriate to distinguish compact embryogenic from friable non-embryogenic callus in sweet potato. In fact, the callus reversion was associated with a loss of bands or a decline in isozyme activity. On the contrary, very small changes in isozyme activity or no specific changes at all were observed during the differentiation of embryogenic callus into globular embryos.

Recovery of methamphetamine associated cardiomyopathy predicted by late gadolinium enhanced cardiovascular magnetic resonance.

PubMed

Lopez, Javier E; Yeo, Khung; Caputo, Gary; Buonocore, Michael; Schaefer, Saul

2009-11-11

Methamphetamine is known to cause a cardiomyopathy which may be reversible with appropriate medical therapy and cessation of use. Late gadolinium enhancement cardiovascular magnetic resonance (CMR) has been shown to identify fibrosis in ischemic and non-ischemic cardiomyopathies. We present a case of severe methamphetamine-associated cardiomyopathy in which cardiac function recovered after 6 months. Evaluation by CMR using late gadolinium enhancement was notable for an absence of enhancement, suggesting an absence of irreversible myocyte injury and a good prognosis. CMR may be useful to predict recovery in toxin-associated non-ischemic cardiomyopathies.

Recovery of methamphetamine associated cardiomyopathy predicted by late gadolinium enhanced cardiovascular magnetic resonance

PubMed Central

2009-01-01

Methamphetamine is known to cause a cardiomyopathy which may be reversible with appropriate medical therapy and cessation of use. Late gadolinium enhancement cardiovascular magnetic resonance (CMR) has been shown to identify fibrosis in ischemic and non-ischemic cardiomyopathies. We present a case of severe methamphetamine-associated cardiomyopathy in which cardiac function recovered after 6 months. Evaluation by CMR using late gadolinium enhancement was notable for an absence of enhancement, suggesting an absence of irreversible myocyte injury and a good prognosis. CMR may be useful to predict recovery in toxin-associated non-ischemic cardiomyopathies. PMID:19906310

Late effects of childhood leukemia therapy.

PubMed

Fulbright, Joy M; Raman, Sripriya; McClellan, Wendy S; August, Keith J

2011-09-01

As survival rates for children treated for childhood cancers become significantly better, the focus is increasingly on determining the late effects of treatments and the best ways to monitor for them and prevent their occurrence. This review focuses on recent literature discussing the late effects of treatment in patients treated for acute myeloid leukemia and acute lymphoblastic leukemia during childhood. The late effects of therapy for childhood leukemia include secondary malignancy, cardiotoxicity, obesity, endocrine abnormalities, reproductive changes, neurocognitive deficits, and psychosocial effects. As clinicians have become more aware of the late effects of therapy, treatment regimens have been changed to decrease late effects, but patients still require long-term follow-up for their prevention and treatment.

Quantitative optical coherence tomography analysis for late in-stent restenotic lesions.

PubMed

Fu, Qiang; Suzuki, Nobuaki; Kozuma, Ken; Miyagawa, Mutsuki; Nomura, Takahiro; Kawashima, Hideyuki; Shiratori, Yoshitaka; Ishikawa, Shuichi; Kyono, Hiroyuki; Isshiki, Takaaki

2015-01-01

Coronary optical coherence tomography (OCT) has the potential to identify in-stent neoatherosclerosis, which is a possible risk factor for late acute coronary events after drug-eluting stent implantation. The purpose of this study was to investigate differences between mid-term and late in-stent restenosis after stent implantation by quantitative and semiautomated tissue property analysis using OCT. In total, 1063 OCT image frames of 16 lesions in 15 patients were analyzed. This included 346 frames of 6 lesions in late in-stent restenosis, which was defined as restenosis that was not detected at 6 to 12 months but ≥ 12 months after follow-up coronary angiography. Signal attenuation was circumferentially analyzed using a dedicated semiautomated software. Attenuation was assessed along 200 lines delineated radially for analysis of the in-stent restenotic lesions (between the lumen and stent contours). All lines were anchored by the image wire to avoid artifacts resulting from wire location. Stronger signal attenuation at the frame level (2.46 ± 0.78 versus 1.47 ± 0.32, P < 0.001) and higher maximum signal intensity at the lesion level (9.19 ± 0.19 versus 8.84 ± 0.32, P = 0.018) were observed in late in-stent restenotic lesions than in mid-term in-stent restenotic lesions. OCT demonstrated stronger signal attenuation and higher maximum signal intensity in late in-stent restenotic lesions than in mid-term in-stent restenotic lesions, indicating the possibility of neoatherosclerosis.

Late Summer Frazil Ice-Associated Algal Blooms around Antarctica

NASA Astrophysics Data System (ADS)

DeJong, Hans B.; Dunbar, Robert B.; Lyons, Evan A.

2018-01-01

Antarctic continental shelf waters are the most biologically productive in the Southern Ocean. Although satellite-derived algorithms report peak productivity during the austral spring/early summer, recent studies provide evidence for substantial late summer productivity that is associated with green colored frazil ice. Here we analyze daily Moderate Resolution Imaging Spectroradiometer satellite images for February and March from 2003 to 2017 to identify green colored frazil ice hot spots. Green frazil ice is concentrated in 11 of the 13 major sea ice production polynyas, with the greenest frazil ice in the Terra Nova Bay and Cape Darnley polynyas. While there is substantial interannual variability, green frazil ice is present over greater than 300,000 km2 during March. Late summer frazil ice-associated algal productivity may be a major phenomenon around Antarctica that is not considered in regional carbon and ecosystem models.

Pre-procambial cells are niches for pluripotent and totipotent stem-like cells for organogenesis and somatic embryogenesis in the peach palm: a histological study.

PubMed

de Almeida, Marcilio; de Almeida, Cristina Vieira; Mendes Graner, Erika; Ebling Brondani, Gilvano; Fiori de Abreu-Tarazi, Monita

2012-08-01

The direct induction of adventitious buds and somatic embryos from explants is a morphogenetic process that is under the influence of exogenous plant growth regulators and its interactions with endogenous phytohormones. We performed an in vitro histological analysis in peach palm (Bactris gasipaes Kunth) shoot apexes and determined that the positioning of competent cells and their interaction with neighboring cells, under the influence of combinations of exogenously applied growth regulators (NAA/BAP and NAA/TDZ), allows the pre-procambial cells (PPCs) to act in different morphogenic pathways to establish niche competent cells. It is likely that there has been a habituation phenomenon during the regeneration and development of the microplants. This includes promoting the tillering of primary or secondary buds due to culturing in the absence of NAA/BAP or NAA/TDZ after a period in the presence of these growth regulators. Histological analyses determined that the adventitious roots were derived from the dedifferentiation of the parenchymal cells located in the basal region of the adventitious buds, with the establishment of rooting pole, due to an auxin gradient. Furthermore, histological and histochemical analyses allowed us to characterize how the PPCs provide niches for multipotent, pluripotent and totipotent stem-like cells for vascular differentiation, organogenesis and somatic embryogenesis in the peach palm. The histological and histochemical analyses also allowed us to detect the unicellular or multicellular origin of somatic embryogenesis. Therefore, our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to potential niche establishment, depending on the positioning of the competent cells and their interaction with neighboring cells. Our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to

A dehydrin-dehydrin interaction: the case of SK3 from Opuntia streptacantha

PubMed Central

Hernández-Sánchez, Itzell E.; Martynowicz, David M.; Rodríguez-Hernández, Aida A.; Pérez-Morales, Maria B.; Graether, Steffen P.; Jiménez-Bremont, Juan F.

2014-01-01

Dehydrins belongs to a large group of highly hydrophilic proteins known as Late Embryogenesis Abundant (LEA) proteins. It is well known that dehydrins are intrinsically disordered plant proteins that accumulate during the late stages of embryogenesis and in response to abiotic stresses; however, the molecular mechanisms by which their functions are carried out are still unclear. We have previously reported that transgenic Arabidopsis plants overexpressing an Opuntia streptacantha SK3 dehydrin (OpsDHN1) show enhanced tolerance to freezing stress. Herein, we show using a split-ubiquitin yeast two-hybrid system that OpsDHN1 dimerizes. We found that the deletion of regions containing K-segments and the histidine-rich region in the OpsDHN1 protein affects dimer formation. Not surprisingly, in silico protein sequence analysis suggests that OpsDHN1 is an intrinsically disordered protein, an observation that was confirmed by circular dichroism and gel filtration of the recombinantly expressed protein. The addition of zinc triggered the association of recombinantly expressed OpsDHN1 protein, likely through its histidine-rich motif. These data brings new insights about the molecular mechanism of the OpsDHN1 SK3-dehydrin. PMID:25346739

Late-onset rhabdomyolysis in burn patients in the intensive care unit.

PubMed

Bache, Sarah E; Taggart, Ian; Gilhooly, Charlotte

2011-11-01

Rhabdomyolysis (RML), defined as creatine phosphokinase (CPK) >1000 U/L, is relatively common immediately after a significant burn. Late-onset RML, occurring a week or more after a burn, is less well understood and recognised. All patients admitted to the Intensive Care Unit (ICU) following an acute burn between May 2006 and December 2009 were retrospectively identified. Patients with CPK>1000 U/L a week or more after their burn had a detailed notes review. Seventy-six patients were admitted during 43 months. Late-onset RML was demonstrated in 7/76 (9%) patients. They had a similar pattern of normal or mildly raised CPK on admission that resolved over the following days, but suddenly increased sharply to over 1000 U/L, a week or more after their burn, usually around day ten. A severe late-onset RML occurred in 5/76 (7%) patients, with a CPK rise of over 5000 U/L, and all required haemodialysis. Potential triggering factors for late-onset RML include sepsis, nephrotoxic drugs and hypophosphataemia. It is important to consider measuring CPK in all patients with the above complications, even after it has previously been observed to be normal, in order to initiate early treatment. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

Silencing of six susceptibility genes results in potato late blight resistance.

PubMed

Sun, Kaile; Wolters, Anne-Marie A; Vossen, Jack H; Rouwet, Maarten E; Loonen, Annelies E H M; Jacobsen, Evert; Visser, Richard G F; Bai, Yuling

2016-10-01

Phytophthora infestans, the causal agent of late blight, is a major threat to commercial potato production worldwide. Significant costs are required for crop protection to secure yield. Many dominant genes for resistance (R-genes) to potato late blight have been identified, and some of these R-genes have been applied in potato breeding. However, the P. infestans population rapidly accumulates new virulent strains that render R-genes ineffective. Here we introduce a new class of resistance which is based on the loss-of-function of a susceptibility gene (S-gene) encoding a product exploited by pathogens during infection and colonization. Impaired S-genes primarily result in recessive resistance traits in contrast to recognition-based resistance that is governed by dominant R-genes. In Arabidopsis thaliana, many S-genes have been detected in screens of mutant populations. In the present study, we selected 11 A. thaliana S-genes and silenced orthologous genes in the potato cultivar Desiree, which is highly susceptible to late blight. The silencing of five genes resulted in complete resistance to the P. infestans isolate Pic99189, and the silencing of a sixth S-gene resulted in reduced susceptibility. The application of S-genes to potato breeding for resistance to late blight is further discussed.

Dynamics of the concentration of IAA and some of its conjugates during the induction of somatic embryogenesis in Coffea canephora

PubMed Central

Ayil-Gutiérrez, Benajmín; Galaz-Ávalos, Rosa María; Peña-Cabrera, Eduardo; Loyola-Vargas, Victor Manuel

2013-01-01

Most of the somatic embryogenesis (SE) process requires the presence, either before or during the embryogenic process, of at least one exogenous auxin. This exogenous auxin induces the presence of endogenous auxins, which appears to be essential for SE induction. We found that during the preincubation period of SE in Coffea canephora, there is an important increase in both free and conjugated indole-3-acetic acid (IAA), as well as indole-3-butyric acid. This increase is accompanied by an increase in the expression of YUCCA (CcYUC), TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (CcTAA1), and GRETCHEN HAGEN 3 (GH3) genes. On the other hand, most of the IAA compounds decreased during the induction of SE. The results presented in this research suggest that a balance between free IAA and its amide conjugates is necessary to allow the expression of SE-related genes. PMID:24299659

The Identification and Assessment of Late-Life ADHD in Memory Clinics

ERIC Educational Resources Information Center

Fischer, Barbara L.; Gunter-Hunt, Gail; Steinhafel, Courtney Holm; Howell, Timothy

2012-01-01

Objective: Little data exist about ADHD in late life. While evaluating patients' memory problems, the memory clinic staff has periodically identified ADHD in previously undiagnosed older adults. The authors conducted a survey to assess the extent to which other memory clinics view ADHD as a relevant clinical issue. Method: The authors developed…

Geochronologic evidence for Late Cretaceous and Miocene tectonism in northern New England

NASA Astrophysics Data System (ADS)

Amidon, W. H.; Barr, M.; Walcott, C.; Kylander-Clark, A. R.

2017-12-01

The persistence of mountainous relief in the northeastern U.S. suggests post-rift tectonic rejuvenation has occurred, although specific mechanisms and timing have been difficult to identify. Here we present direct evidence for significant tectonism in New Hampshire and Vermont during the Late-Cretaceous ( 85-65 Ma) and Miocene periods ( 20-5 Ma). Low temperature thermochronology from a drill core in the White Mountains of New Hampshire suggests 2-3 km of accelerated exhumation during the Late Cretaceous. This exhumation is synchronous with compressional thrusting and rapid exhumation on many other Atlantic margins and also with a change in spreading direction in the Atlantic from 85-65 Ma. Recently obtained U-Pb ages of vein calcite from faults and fractures in the Champlain Valley of New York and Vermont suggest significant brittle fracturing occurred during the Late Cretaceous and also during the Miocene. Although many questions remain, this evidence points to tectonic rejuvenation by lateral tectonic stresses in the latest Cretaceous and possibly in the Miocene. The Late Cretaceous seems to have been a particularly significant tectonic episode in northern New England and elsewhere in the circum-Atlantic region.

Late Talkers: A Population-Based Study of Risk Factors and School Readiness Consequences.

PubMed

Hammer, Carol Scheffner; Morgan, Paul; Farkas, George; Hillemeier, Marianne; Bitetti, Dana; Maczuga, Steve

2017-03-01

This study was designed to (a) identify sociodemographic, pregnancy and birth, family health, and parenting and child care risk factors for being a late talker at 24 months of age; (b) determine whether late talkers continue to have low vocabulary at 48 months; and (c) investigate whether being a late talker plays a unique role in children's school readiness at 60 months. We analyzed data from the Early Childhood Longitudinal Study, a population-based sample of 9,600 children. Data were gathered when the children were 9, 24, 48, and 60 months old. The risk of being a late talker at 24 months was significantly associated with being a boy, lower socioeconomic status, being a nonsingleton, older maternal age at birth, moderately low birth weight, lower quality parenting, receipt of day care for less than 10 hr/week, and attention problems. Being a late talker increased children's risk of having low vocabulary at 48 months and low school readiness at 60 months. Family socioeconomic status had the largest and most profound effect on children's school readiness. Limited vocabulary knowledge at 24 and 48 months is uniquely predictive of later school readiness. Young children with low vocabularies require additional supports prior to school entry.

GWAS-identified risk variants for major depressive disorder: Preliminary support for an association with late-life depressive symptoms and brain structural alterations.

PubMed

Ryan, Joanne; Artero, Sylvaine; Carrière, Isabelle; Maller, Jerome J; Meslin, Chantal; Ritchie, Karen; Ancelin, Marie-Laure

2016-01-01

A number of genome-wide association studies (GWAS) have investigated risk factors for major depressive disorder (MDD), however there has been little attempt to replicate these findings in population-based studies of depressive symptoms. Variants within three genes, BICC1, PCLO and GRM7 were selected for replication in our study based on the following criteria: they were identified in a prior MDD GWAS study; a subsequent study found evidence that they influenced depression risk; and there is a solid biological basis for a role in depression. We firstly investigated whether these variants were associated with depressive symptoms in our population-based cohort of 929 elderly (238 with clinical depressive symptoms and 691 controls), and secondly to investigate associations with structural brain alterations. A number of nominally significant associations were identified, but none reached Bonferroni-corrected significance levels. Common SNPs in BICC1 and PCLO were associated with a 50% and 30% decreased risk of depression, respectively. PCLO rs2522833 was also associated with the volume of grey matter (p=1.6×10(-3)), and to a lesser extent with hippocampal volume and white matter lesions. Among depressed individuals rs9870680 (GRM7) was associated with the volume of grey and white matter (p=10(-4) and 8.3×10(-3), respectively). Our results provide some support for the involvement of BICC1 and PCLO in late-life depressive disorders and preliminary evidence that these genetic variants may also influence brain structural volumes. However effect sizes remain modest and associations did not reach corrected significance levels. Further large imaging studies are needed to confirm our findings. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

Mps1 (Monopolar Spindle 1) Protein Inhibition Affects Cellular Growth and Pro-Embryogenic Masses Morphology in Embryogenic Cultures of Araucaria angustifolia (Araucariaceae).

PubMed

Douétts-Peres, Jackellinne C; Cruz, Marco Antônio L; Reis, Ricardo S; Heringer, Angelo S; de Oliveira, Eduardo A G; Elbl, Paula M; Floh, Eny I S; Silveira, Vanildo; Santa-Catarina, Claudete

2016-01-01

Somatic embryogenesis has been shown to be an efficient tool for studying processes based on cell growth and development. The fine regulation of the cell cycle is essential for proper embryo formation during the process of somatic embryogenesis. The aims of the present work were to identify and perform a structural and functional characterization of Mps1 and to analyze the effects of the inhibition of this protein on cellular growth and pro-embryogenic mass (PEM) morphology in embryogenic cultures of A. angustifolia. A single-copy Mps1 gene named AaMps1 was retrieved from the A. angustifolia transcriptome database, and through a mass spectrometry approach, AaMps1 was identified and quantified in embryogenic cultures. The Mps1 inhibitor SP600125 (10 μM) inhibited cellular growth and changed PEMs, and these effects were accompanied by a reduction in AaMps1 protein levels in embryogenic cultures. Our work has identified the Mps1 protein in a gymnosperm species for the first time, and we have shown that inhibiting Mps1 affects cellular growth and PEM differentiation during A. angustifolia somatic embryogenesis. These data will be useful for better understanding cell cycle control during somatic embryogenesis in plants.

Mps1 (Monopolar Spindle 1) Protein Inhibition Affects Cellular Growth and Pro-Embryogenic Masses Morphology in Embryogenic Cultures of Araucaria angustifolia (Araucariaceae)

PubMed Central

Douétts-Peres, Jackellinne C.; Cruz, Marco Antônio L.; Reis, Ricardo S.; Heringer, Angelo S.; de Oliveira, Eduardo A. G.; Elbl, Paula M.; Floh, Eny I. S.; Silveira, Vanildo

2016-01-01

Somatic embryogenesis has been shown to be an efficient tool for studying processes based on cell growth and development. The fine regulation of the cell cycle is essential for proper embryo formation during the process of somatic embryogenesis. The aims of the present work were to identify and perform a structural and functional characterization of Mps1 and to analyze the effects of the inhibition of this protein on cellular growth and pro-embryogenic mass (PEM) morphology in embryogenic cultures of A. angustifolia. A single-copy Mps1 gene named AaMps1 was retrieved from the A. angustifolia transcriptome database, and through a mass spectrometry approach, AaMps1 was identified and quantified in embryogenic cultures. The Mps1 inhibitor SP600125 (10 μM) inhibited cellular growth and changed PEMs, and these effects were accompanied by a reduction in AaMps1 protein levels in embryogenic cultures. Our work has identified the Mps1 protein in a gymnosperm species for the first time, and we have shown that inhibiting Mps1 affects cellular growth and PEM differentiation during A. angustifolia somatic embryogenesis. These data will be useful for better understanding cell cycle control during somatic embryogenesis in plants. PMID:27064899

Adult Langerhans cells derive predominantly from embryonic fetal liver monocytes with a minor contribution of yolk sac-derived macrophages.

PubMed

Hoeffel, Guillaume; Wang, Yilin; Greter, Melanie; See, Peter; Teo, Pearline; Malleret, Benoit; Leboeuf, Marylène; Low, Donovan; Oller, Guillaume; Almeida, Francisca; Choy, Sharon H Y; Grisotto, Marcos; Renia, Laurent; Conway, Simon J; Stanley, E Richard; Chan, Jerry K Y; Ng, Lai Guan; Samokhvalov, Igor M; Merad, Miriam; Ginhoux, Florent

2012-06-04

Langerhans cells (LCs) are the dendritic cells (DCs) of the epidermis, forming one of the first hematopoietic lines of defense against skin pathogens. In contrast to other DCs, LCs arise from hematopoietic precursors that seed the skin before birth. However, the origin of these embryonic precursors remains unclear. Using in vivo lineage tracing, we identify a first wave of yolk sac (YS)-derived primitive myeloid progenitors that seed the skin before the onset of fetal liver hematopoiesis. YS progenitors migrate to the embryo proper, including the prospective skin, where they give rise to LC precursors, and the brain rudiment, where they give rise to microglial cells. However, in contrast to microglia, which remain of YS origin throughout life, YS-derived LC precursors are largely replaced by fetal liver monocytes during late embryogenesis. Consequently, adult LCs derive predominantly from fetal liver monocyte-derived cells with a minor contribution of YS-derived cells. Altogether, we establish that adult LCs have a dual origin, bridging early embryonic and late fetal myeloid development.

Adult Langerhans cells derive predominantly from embryonic fetal liver monocytes with a minor contribution of yolk sac–derived macrophages

PubMed Central

Hoeffel, Guillaume; Wang, Yilin; Greter, Melanie; See, Peter; Teo, Pearline; Malleret, Benoit; Leboeuf, Marylène; Low, Donovan; Oller, Guillaume; Almeida, Francisca; Choy, Sharon H.Y.; Grisotto, Marcos; Renia, Laurent; Conway, Simon J.; Stanley, E. Richard; Chan, Jerry K.Y.; Ng, Lai Guan; Samokhvalov, Igor M.

2012-01-01

Langerhans cells (LCs) are the dendritic cells (DCs) of the epidermis, forming one of the first hematopoietic lines of defense against skin pathogens. In contrast to other DCs, LCs arise from hematopoietic precursors that seed the skin before birth. However, the origin of these embryonic precursors remains unclear. Using in vivo lineage tracing, we identify a first wave of yolk sac (YS)–derived primitive myeloid progenitors that seed the skin before the onset of fetal liver hematopoiesis. YS progenitors migrate to the embryo proper, including the prospective skin, where they give rise to LC precursors, and the brain rudiment, where they give rise to microglial cells. However, in contrast to microglia, which remain of YS origin throughout life, YS-derived LC precursors are largely replaced by fetal liver monocytes during late embryogenesis. Consequently, adult LCs derive predominantly from fetal liver monocyte-derived cells with a minor contribution of YS-derived cells. Altogether, we establish that adult LCs have a dual origin, bridging early embryonic and late fetal myeloid development. PMID:22565823

[Hypochondriac symptoms in late-onset depression: the relationship between hypochondria and somatic state of patients].

PubMed

Ivanets, N N; Avdeeva, T I; Kinkul'kina, M A

2013-01-01

Authors studied 276 women with late-onset depression. Concomitant chronic somatic diseases were identified in 90%. The presence of disease and its nosological definition did not impact on the development of hypochondriac symptoms in patients with late-onset depression. Patients with hypochondriac late-onset depression more often had disability pension due to somatic disease because they more often referred to internists in case of similar objective severity of somatic pathology. It was singled out three variants of the relationship between hypochondria and somatic state: hypernosognostic (a complete coincidence of hypochondria content with actual somatic pathology; anosognostic (a lack of coincidence) and disharmonic (a partial coincidence). The themes of hypochondria in late-nset depressions were correlated with a total number of somatic diseases and their severity. At the same time, there was no correlation between the content of hypochondria and the character of somatic disease.

The Use of Proteomic Tools to Address Challenges Faced in Clonal Propagation of Tropical Crops through Somatic Embryogenesis.

PubMed

Chin, Chiew Foan; Tan, Hooi Sin

2018-05-04

In many tropical countries with agriculture as the mainstay of the economy, tropical crops are commonly cultivated at the plantation scale. The successful establishment of crop plantations depends on the availability of a large quantity of elite seedling plants. Many plantation companies establish plant tissue culture laboratories to supply planting materials for their plantations and one of the most common applications of plant tissue culture is the mass propagation of true-to-type elite seedlings. However, problems encountered in tissue culture technology prevent its applications being widely adopted. Proteomics can be a powerful tool for use in the analysis of cultures, and to understand the biological processes that takes place at the cellular and molecular levels in order to address these problems. This mini review presents the tissue culture technologies commonly used in the propagation of tropical crops. It provides an outline of some the genes and proteins isolated that are associated with somatic embryogenesis and the use of proteomic technology in analysing tissue culture samples and processes in tropical crops.

Coping – Late Side Effects

Cancer.gov

Cancer treatment can cause late side effects that may not show up for months or years after treatment. These late effects may include heart and lung problems, bone loss, eye and hearing changes, lymphedema, and other problems

Unmatched Case-Control Study on Late Presentation of HIV Infection in Santiago, Cape Verde (2004-2011).

PubMed

Moreira, António L; Fronteira, Inês; Augusto, Gonçalo Figueiredo; Martins, Maria Rosario O

2016-03-15

Access to free antiretroviral therapy (ART) in Sub-Saharan Africa has been steadily increasing over the past decade. However, the success of large-scale ART programmes depends on timely diagnosis and early initiation of HIV care. This study characterizes late presenters to HIV care in Santiago (Cape Verde) between 2004 and 2011, and identifies factors associated with late presentation for care. We defined late presentation as persons presenting to HIV care with a CD4 count below 350 cells/mm³. An unmatched case-control study was conducted using socio-demographic and behavioural data of 368 individuals (191 cases and 177 controls) collected through an interviewer-administered questionnaire, comparing HIV patients late and early presented to care. Logistic regression was performed to estimate odds ratio and 95% confidence intervals. Results show that 51.9% were late presenters for HIV. No differences were found in gender distribution, marital status, or access to health services between cases and controls. Participants who undertook an HIV test by doctor indication were more likely to present late compared with those who tested for HIV by their own initiative. Also, individuals taking less time to initiate ART are more likely to present late. This study highlights the need to better understand reasons for late presentation to HIV care in Cape Verde. People in older age groups should be targeted in future approaches focused on late presenters to HIV care.

The anatomy of a major late-stage thrust and implications for models of late-stage collisional orogenesis in the Caledonian crust of northern Scandinavia

NASA Astrophysics Data System (ADS)

Anderson, Mark; Hames, Willis; Stokes, Alison

2010-05-01

Within the stack of Caledonian crystalline thrust sheets of northern Scandinavia, a single amphibolite facies lithotectonic unit, the Småtinden nappe, is identified as a major, basement-coupled ("stretching") shear zone. This dominantly pelitic unit achieved peak metamorphic conditions of 535-550°C and 8-9kbars, and the stretching geometry suggests that this most likely occurred in response to overthrusting of a hot, pre-assembled Caledonian thrust stack. Along-strike variations in microstructural geometries and patterns of mineral zoning in widely developed porphyroblast phases suggest, however, subsequent strain partitioning within the zone during late-stage decoupling of the thrust stack from the basement along major out-of-sequence thrusts. Large parts of the nappe are characterised by relatively late, static growth preserving concordant Si-Se relationships, and typically symmetrical external fabrics consistent with formation under dominantly pure shear conditions. In the Salangen area, however, the nappe is characterised by early garnet growth, with discordant Si-Se relationships and asymmetric external fabric geometries consistent with formation during ESE-directed simple shear. Remarkably consistent thermometric estimates from chlorites in both regimes (post- and syn-shearing) suggest that out-of-sequence ramping occurred at temperatures in the range 370-400 ̊C, within the typical range of blocking temperatures for argon retention in muscovite. 40Ar-39Ar dating of muscovites from S-C fabrics in the out-of-sequence shear zone suggest that late-stage thrusting occurred during the middle-late Devonian (ca. 395-375 Ma). Hanging-wall and footwall geometries coupled with these radiometric dates indicate that the development of these late thrusts closely relates to reactivation of pre-Caledonian Baltic basement during the Devonian (400-370 Ma). East-west contraction during the upper end of this time frame is peculiar considering that this was the period of large

Late-stage galaxy mergers in cosmos to z ∼ 1

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

Lackner, C. N.; Silverman, J. D.; Salvato, M.

2014-12-01

The role of major mergers in galaxy and black hole formation is not well-constrained. To help address this, we develop an automated method to identify late-stage galaxy mergers before coalescence of the galactic cores. The resulting sample of mergers is distinct from those obtained using pair-finding and morphological indicators. Our method relies on median-filtering of high-resolution images to distinguish two concentrated galaxy nuclei at small separations. This method does not rely on low surface brightness features to identify mergers, and is therefore reliable to high redshift. Using mock images, we derive statistical contamination and incompleteness corrections for the fraction ofmore » late-stage mergers. The mock images show that our method returns an uncontaminated (<10%) sample of mergers with projected separations between 2.2 and 8 kpc out to z∼1. We apply our new method to a magnitude-limited (m{sub FW} {sub 814}<23) sample of 44,164 galaxies from the COSMOS HST/ACS catalog. Using a mass-complete sample with logM{sub ∗}/M{sub ⊙}>10.6 and 0.25« less

IVUS Findings in Late and Very Late Stent Thrombosis. A Comparison Between Bare-metal and Drug-eluting Stents.

PubMed

Fuentes, Lara; Gómez-Lara, Josep; Salvatella, Neus; Gonzalo, Nieves; Hernández-Hernández, Felipe; Fernández-Nofrerias, Eduard; Sánchez-Recalde, Ángel; Alfonso, Fernando; Romaguera, Rafael; Ferreiro, José Luis; Roura, Gerard; Teruel, Luis; Gracida, Montserrat; Marcano, Ana Lucrecia; Gómez-Hospital, Joan-Antoni; Cequier, Ángel

2018-05-01

Stent thrombosis (ST) is a life-threatening complication after stent implantation. Intravascular ultrasound is able to discern most causes of ST. The aim of this study was to compare intravascular ultrasound findings between bare-metal stents (BMS) and drug-eluting stents (DES) in patients with late (31 days to 1 year) or very late ST (> 1 year). Of 250 consecutive patients with late or very late ST in 7 Spanish institutions, 114 patients (45.5% BMS and 54.5% DES) were imaged with intravascular ultrasound. Off-line intravascular ultrasound analysis was performed to assess malapposition, underexpansion, and neoatherosclerosis. The median time from stent implantation to ST was 4.0 years with BMS and 3.4 years with DES (P = .04). Isolated malapposition was similarly observed in both groups (36.5% vs 46.8%; P = .18) but was numerically lower with BMS (26.6% vs 48.0%; P = .07) in patients with very late ST. Isolated underexpansion was similarly observed in both groups (13.5% vs 11.3%; P = .47). Isolated neoatherosclerosis occurred only in patients with very late ST and was more prevalent with BMS (22.9%) than with DES (6.0%); P = .02. At 2.9 years' follow-up, there were 0% and 6.9% cardiac deaths, respectively (P = .06) and recurrent ST occurred in 4.0% and 5.2% of patients, respectively (P = .60). Malapposition was the most common finding in patients with late and very late ST and is more prevalent with DES in very late ST. In contrast, neoatherosclerosis was exclusively observed in patients with very late ST and mainly with BMS. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Identifying novel members of the Wntless interactome through genetic and candidate gene approaches.

PubMed

Petko, Jessica; Tranchina, Trevor; Patel, Goral; Levenson, Robert; Justice-Bitner, Stephanie

2018-04-01

Wnt signaling is an important pathway that regulates several aspects of embryogenesis, stem cell maintenance, and neural connectivity. We have recently determined that opioids decrease Wnt secretion, presumably by inhibiting the recycling of the Wnt trafficking protein Wntless (Wls). This effect appears to be mediated by protein-protein interaction between Wls and the mu-opioid receptor (MOR), the primary cellular target of opioid drugs. The goal of this study was to identify novel protein interactors of Wls that are expressed in the brain and may also play a role in reward or addiction. Using genetic and candidate gene approaches, we show that among a variety of protein, Wls interacts with the dopamine transporter (target of cocaine), cannabinoid receptors (target of THC), Adenosine A2A receptor (target of caffeine), and SGIP1 (endocytic regulator of cannabinoid receptors). Our study shows that aside from opioid receptors, Wntless interacts with additional proteins involved in reward and/or addiction. Future studies will determine whether Wntless and WNT signaling play a more universal role in these processes. Copyright © 2017 Elsevier Inc. All rights reserved.

Late-onset Huntington's disease: diagnostic and prognostic considerations.

PubMed

Koutsis, Georgios; Karadima, Georgia; Kladi, Athina; Panas, Marios

2014-07-01

To address diagnostic and prognostic issues in patients with late-onset Huntington's disease (HD). We analyzed a cohort of 41 late-onset (≥60 years) HD patients and compared them to 39 late-onset patients referred for HD testing that were negative for the HD-expansion and to 290 usual-onset (20-59 years) HD patients. Disease severity was assessed by the Total Functional Capacity Scale. Late-onset HD comprised 11.5% of our HD cohort. In total, 70.7% of late-onset HD patients had positive family history compared to 15.4% of late-onset expansion-negative patients (p < 0.001). Clinical features at onset or presentation could not usefully distinguish between late-onset expansion-positive and negative patients, excepting hemichorea, which was absent from the HD group (p = 0.024). Chorea was the first clinical feature in 53.7% and a presenting feature in 90.2% of late-onset HD. The mutation hit rate for late-onset patients was 51.3%, lower than in usual-onset patients (p = 0.04). Frequencies of chorea, cognitive impairment and psychiatric manifestations at onset or presentation were not significantly different between late-onset and usual-onset HD patients. Gait unsteadiness however was more common at presentation in late-onset HD (p = 0.007). Late-onset HD patients reached a severe stage of illness on average 2.8 years earlier than usual-onset HD patients (p = 0.046). A positive family history suggestive of HD, although absent in a third of patients, remains a helpful clue in diagnosing late-onset HD. Prognosis of late-onset HD in terms of Total Functional Capacity appears no better and shows a trend of being somewhat less favorable compared to usual-onset HD. Copyright © 2014 Elsevier Ltd. All rights reserved.

Micropropagation of Codiaeum variegatum (L.) Blume and regeneration induction via adventitious buds and somatic embryogenesis.

PubMed

Radice, Silvia

2010-01-01

Codiaeum variegatum (L) Blume cv. "Corazon de oro" and cv. "Norma" are successfully micropropagated when culture are initiated with explants taken from newly sprouted shoots. The establishment and multiplication steps are possible when 1 mg/L BA or 1 mg/L IAA and 3 mg/L 2iP are added to MS medium, according to the cultivar respectively selected.Adventive organogenesis and somatic embryogenesis are induced from leaf explants taken from in vitro buds of croton. On leaf-sectioned of "Corazon de oro" cultured in vitro, 1 mg/L BA stimulates continuous somatic embryos development and induces some shoots too. Replacing BA with 1 mg/L TDZ induces up to 100% bud regeneration in the same explants. On the other hand, leaf-sectioned of C. variegatum cv. Norma does not start somatic embryo differentiation if 1 mg/L TDZ is not added to the MS basal medium. Incipient callus is observed after 30 days of culture, and then, subculture to MS with 1 mg/L BA allows the same process to show on the "Corazon de oro" cultivar. Somatic embryos show growth arrest that is partially overcome by transfer to hormone-free basal medium with activated charcoal. Root induction is possible on basal medium plus 1 mg/L IBA. Plantlets in the greenhouse have variegated leaves true-to-type.

Self- and Peer-Identified Victims in Late Childhood: Differences in Perceptions of the School Ecology.

PubMed

Dawes, Molly; Chen, Chin-Chih; Farmer, Thomas W; Hamm, Jill V

2017-11-01

Patterns of adjustment for youth victimized by peers vary depending on whether youth are identified as victims through self-reports, peer-reports, or both. In order to provide more targeted strategies that may help mitigate negative consequences associated with specific victimization groups, more information is needed about how these youth perceive their school ecology (bullying and academic ecology), their feelings of school belonging, and their valuing of school. Based on the convergence of self- and peer-reports of victimization, we identified four victim groups from a sample of students in 5th grade classrooms (N = 1360; 52.8% girls, 53.1% White, 34.6% Black or Hispanic, 12.2% Native American, Asian, or other) using Latent Profile Analysis (LPA): convergent victims (high self- and peer-reports), self-identified victims (high self-, low peer-reports), peer-identified victims (low self-, high peer-reports), and nonvictims (low self- and peer-reports). Convergent victims' perceptions were similar to nonvictims with key differences being convergent victims' greater willingness to protect peers being bullied but lower feelings of school belonging compared to nonvictims. Peer-identified and self-identified victims perceived differences in the bullying and academic ecology including peer-identified victims' greater willingness to protect peers and expectations for more peers to encourage bulling against them compared to self-identified victims. However, both peer- and self-identified victims perceived greater emotional risk of participating in class and had lower feelings of school belonging compared to nonvictims. Implications for supporting youth with divergent self- and peer-reported victimization status as they transition to middle school are discussed.

Late entry to HIV and AIDS care and treatment, Juba Teaching Hospital, Juba, South Sudan, 2013-2016.

PubMed

Johnson, Muki; Lemi, Benjamin L; Tonny, Hillary L; David, Adelina D; Boru, Waqo; Ransom, James

2018-05-10

Late diagnosis of HIV and enrolment to care are global public health challenges. This study aimed to characterise late HIV diagnoses and initiation of treatment among patients at Juba Teaching Hospital (JTH) in South Sudan. We conducted a retrospective review of lab-confirmed HIV patients at JTH, 2013-2016. Demographic, clinical, and laboratory data were entered into and descriptive statistics were calculated using Microsoft Excel. We identified 401 patients, with mean age 33.71±4.54 years, 235 (59%) were female, 307 (77%) were late entry, 64 (16%) were lost to follow-up, and 57 (14%) died within 12 months of diagnosis. Among patients who presented late, 122 (57%) were female, and 112 (53%) were <34 years old. Among patients who died, 33 (58%) were male, and 52 (91%) had CD4 counts <350 cells/mm3 and World Health Organization (WHO) stage >2 at diagnosis. Late diagnosis of HIV infection is a significant public health problem in South Sudan, particularly for younger and female patients.

Impact of Growing Up with a Chronically Ill Sibling on Well Siblings' Late Adolescent Functioning

PubMed Central

Fleary, Sasha A.; Heffer, Robert W.

2013-01-01

The purpose of this study was to explore the continuing impact of growing up with an ill sibling on well siblings' late adolescent functioning. Forty late adolescents (M age = 18.78, SD = 0.83), who identified themselves as growing up with an ill sibling, completed a semistructured interview, demographic questionnaire, Personality Assessment Screener, and My Feelings and Concerns Sibling Questionnaire. Participants reported clinically significant problems on some PAS scales, and gender differences were found for acting out and alienation. Significant relationships were reported for communication and social withdrawal and alienation. Both positive and negative themes about the experience were elicited from the responses in the semistructured interview. This study provides evidence for some lingering negative effects of growing up with an ill sibling on well siblings' late adolescent functioning. Additionally, evidence for siblings' development of positive characteristics that may act as protective variables as they face the stressors of late adolescence was also highlighted. PMID:24959574

Combining moderators to identify clinical profiles of patients who will, and will not, benefit from aripiprazole augmentation for treatment resistant late-life major depressive disorder

PubMed Central

Smagula, Stephen F.; Wallace, Meredith L.; Anderson, Stewart J.; Karp, Jordan F.; Lenze, Eric J.; Mulsant, Benoit H.; Butters, Meryl A.; Blumberger, Daniel M.; Diniz, Breno S.; Lotrich, Francis; Dew, Mary Amanda; Reynolds, Charles F.

2016-01-01

Personalizing treatment for late-life depression requires identifying and integrating information from multiple factors that influence treatment efficacy (moderators). We performed exploratory moderator analyses using data from a multi-site, randomized, placebo-controlled, double-blind trial of aripiprazole augmentation. Patients (n=159) aged ≥60 years had major depressive disorder that failed to remit with venlafaxine monotherapy. We examined effect sizes of 39 potential moderators of aripiprazole (vs. placebo) augmentation efficacy using the outcome of percentage reduction in depressive symptom after 12 weeks. We then incorporated information from the individually relevant variables in combined moderators. A larger aripiprazole treatment effect was related to: white race, better physical function, better performance on Trail-Making, attention, immediate, and delayed memory tests, greater psychomotor agitation and suicidality symptoms, and a history of adequate antidepressant pharmacotherapy. A smaller aripiprazole treatment effect was observed in patients with: more pain and more work/activity impairment and libido symptoms. Combining information from race and Trail-Making test performance (base combined moderator (Mb*)) produced a larger effect size (Spearman effect size=0.29 (95% confidence interval (CI): 0.15, 0.42)) than any individual moderator. Adding other individually relevant moderators in the full combined moderator (Mf*) further improved effect size (Spearman effect size=0.39 (95% CI: 0.25, 0.52)) and identified a sub-group benefiting more from placebo plus continuation venlafaxine monotherapy than adjunctive aripiprazole. Combining moderators can help clinicians personalize depression treatment. We found the majority of our patients benefited from adjunctive aripiprazole, but a smaller subgroup that is identifiable using clinical measures appeared to benefit more from continuation venlafaxine plus placebo. PMID:27438687

Molecular characterization of late stomal recurrence following total laryngectomy.

PubMed

Stephen, Josena K; Symal, Mausumi; Chen, Kang Mei; Ghanem, Tamer; Deeb, Robert; Shah, Veena; Havard, Shaleta; Worsham, Maria J

2011-03-01

The goal was to determine recurrent or second primary status for late stomal malignancies, 16 and 17 years post-total laryngectomy in two laryngeal squamous cell carcinoma (LSCC) patients, based on DNA methylation signatures and HPV typing. Adopting a literature review based definition of late stomal recurrences as new primaries at the site of the stoma or neopharynx occurring >5 years after total laryngectomy, we employed a multi-gene candidate approach to examine promoter methylation in 24 tumor suppressor genes and PCR-based assays for HPV status offered additional insights into whether the late stomal tumors post-total laryngectomy were related or not. The primary tumor for Patient 1 was negative for HPV but had aberrant hypermethylation of APC, MLH1 and BRCA1. The stomal biopsy 17-years later showed presence of HPV-16 without any methylated genes. In Patient 2, HPV-11 and promoter methylation of APC identified in the primary tumor was also observed in the stomal malignancy 16 years post-total laryngectomy. Additional information provided by molecular typing for HPV and methylation markers underscored Patient 1's and 2's late stomal presentation as most likely a second primary and recurrence, respectively. DNA methylation markers are particularly advantageous because DNA methylation is an early event in tumorigenesis, and the epigenetic modification, 5-methylcytosine, is a stable marker. Molecular marks to discern genetic heterogeneity or relatedness of stomal malignancies several years post-total laryngectomy can provide clues to their status as either second primaries or likely recurrences. Our results support the hypothesis that a subset of stomal recurrences after total laryngectomy represents second primary tumors.

Late-paleozoic granitoid complexes of the southwest Primorye: geochemistry, age and typification

NASA Astrophysics Data System (ADS)

Veldemar, A. A.; Vovna, G. M.

2017-12-01

The article presents the first data of geochemical studies of the Late Permian granitoids of the Gamov Complex located in the southwestern part of the Voznesenskiy terrane. The purpose of the study was to identify the main geochemical features of the Late Paleozoic granitoids of the southwestern Primorye, which in the future will allow us to draw conclusions about the petrogenesis of these granitoids. Elemental analysis of 20 samples was carried out, conducted statistical and mathematical processing of the data, have been constructed representative diagrams and graphs for this group of rocks. Elemental analysis was performed by atomic emission (ICP-AES) and inductively-coupled-plasma (ICP-MS) mass spectrometry, at the Analytical Center FEGI FEB RAS.

Late Pleistocene-Holocene volcanic activity in northern Victoria Land recorded in Ross Sea (Antarctica) marine sediments

NASA Astrophysics Data System (ADS)

Del Carlo, P.; Di Roberto, A.; Di Vincenzo, G.; Bertagnini, A.; Landi, P.; Pompilio, M.; Colizza, E.; Giordano, G.

2015-05-01

Eight pyroclastic fall deposits have been identified in cores of Late Pleistocene-Holocene marine sediments from the Ross Sea (Antarctica), and their components, granulometry and clast morphologies were analysed. Sedimentological, petrographic and geochemical analysis of clasts, with 40Ar-39Ar dating of alkali feldspar grains, indicate that during this period at least five explosive eruptions of mid to high intensity (plinian to subplinian) occurred, and that three of these eruptions took place from Mount Melbourne volcanic complex, between 137.1 ± 3.4 and 12 ka. Geochemical comparison of the studied tephra with micro- and crypto-tephra recovered from deep Antarctic ice cores and from nearby englacial tephra at Frontier Mountain indicates that eruptive activity in the Melbourne Volcanic Province of northern Victoria Land was intense during the Late Pleistocene-Holocene, but only a general area of provenance for the majority of the identified tephra can be identified.

Unmatched Case-Control Study on Late Presentation of HIV Infection in Santiago, Cape Verde (2004–2011)

PubMed Central

Moreira, António L.; Fronteira, Inês; Augusto, Gonçalo Figueiredo; Martins, Maria Rosario O.

2016-01-01

Access to free antiretroviral therapy (ART) in Sub-Saharan Africa has been steadily increasing over the past decade. However, the success of large-scale ART programmes depends on timely diagnosis and early initiation of HIV care. This study characterizes late presenters to HIV care in Santiago (Cape Verde) between 2004 and 2011, and identifies factors associated with late presentation for care. We defined late presentation as persons presenting to HIV care with a CD4 count below 350 cells/mm3. An unmatched case-control study was conducted using socio-demographic and behavioural data of 368 individuals (191 cases and 177 controls) collected through an interviewer-administered questionnaire, comparing HIV patients late and early presented to care. Logistic regression was performed to estimate odds ratio and 95% confidence intervals. Results show that 51.9% were late presenters for HIV. No differences were found in gender distribution, marital status, or access to health services between cases and controls. Participants who undertook an HIV test by doctor indication were more likely to present late compared with those who tested for HIV by their own initiative. Also, individuals taking less time to initiate ART are more likely to present late. This study highlights the need to better understand reasons for late presentation to HIV care in Cape Verde. People in older age groups should be targeted in future approaches focused on late presenters to HIV care. PMID:26999167

Viral DNA Replication Orientation and hnRNPs Regulate Transcription of the Human Papillomavirus 18 Late Promoter.

PubMed

Wang, Xiaohong; Liu, Haibin; Ge, Hui; Ajiro, Masahiko; Sharma, Nishi R; Meyers, Craig; Morozov, Pavel; Tuschl, Thomas; Klar, Amar; Court, Donald; Zheng, Zhi-Ming

2017-05-30

The life cycle of human papillomaviruses (HPVs) is tightly linked to keratinocyte differentiation. Although expression of viral early genes is initiated immediately upon virus infection of undifferentiated basal cells, viral DNA amplification and late gene expression occur only in the mid to upper strata of the keratinocytes undergoing terminal differentiation. In this report, we show that the relative activity of HPV18 TATA-less late promoter P 811 depends on its orientation relative to that of the origin (Ori) of viral DNA replication and is sensitive to the eukaryotic DNA polymerase inhibitor aphidicolin. Additionally, transfected 70-nucleotide (nt)-long single-strand DNA oligonucleotides that are homologous to the region near Ori induce late promoter activity. We also found that promoter activation in raft cultures leads to production of the late promoter-associated, sense-strand transcription initiation RNAs (tiRNAs) and splice-site small RNAs (spliRNAs). Finally, a cis -acting AAGTATGCA core element that functions as a repressor to the promoter was identified. This element interacts with hnRNP D0B and hnRNP A/B factors. Point mutations in the core prevented binding of hnRNPs and increased the promoter activity. Confirming this result, knocking down the expression of both hnRNPs in keratinocytes led to increased promoter activity. Taking the data together, our study revealed the mechanism of how the HPV18 late promoter is regulated by DNA replication and host factors. IMPORTANCE It has been known for decades that the activity of viral late promoters is associated with viral DNA replication among almost all DNA viruses. However, the mechanism of how DNA replication activates the viral late promoter and what components of the replication machinery are involved remain largely unknown. In this study, we characterized the P 811 promoter region of HPV18 and demonstrated that its activation depends on the orientation of DNA replication. Using single

Management of Immediate Post-Endovascular Aortic Aneurysm Repair Type Ia Endoleaks and Late Outcomes

PubMed Central

AbuRahma, Ali F; Hass, Stephen M; AbuRahma, Zachary T; Yacoub, Michael; Mousa, Albeir Y; Abu-Halimah, Shadi; Dean, L Scott; Stone, Patrick A

2017-01-01

BACKGROUND Post-endovascular aortic aneurysm repair (EVAR) endoleaks and the need for reintervention are challenging. Additional endovascular treatment is advised for type Ia endoleaks detected on post-EVAR completion angiogram. This study analyzed management and late outcomes of these endoleaks. STUDY DESIGN This was a retrospective review of prospectively collected data from EVAR patients during a 10-year period. All post-EVAR type Ia endoleaks on completion angiogram were identified (group A) and their early (30-day) and late outcomes were compared with outcomes of patients without endoleaks (group B). Kaplan-Meier analysis was used for survival analysis, sac expansion, late type Ia endoleak, and reintervention. RESULTS Seventy-one of 565 (12.6%) patients had immediate post-EVAR type Ia endoleak. Early intervention (proximal aortic cuffs and/or stenting) was used in 56 of 71 (79%) in group A vs 31 of 494 (6%) in group B (p < 0.0001). Late type Ia endoleak was noted in 9 patients (13%) in group A at a mean follow-up of 28 months vs 10 patients (2%) in group B at a mean follow-up of 32 months (p < 0.0001). Late sac expansion and reintervention rates were 9% and 10% for group A vs 5% and 3% for group B (p = 0.2698 and p = 0.0198), respectively. Freedom rates from late type Ia endoleaks at 1, 3, and 5 years for group A were 88%, 85%, and 80% vs 98%, 98%, and 96% for group B (p < 0.001); and for late intervention, were 94%, 92%, and 77% for group A, and 99%, 97%, and 95% for group B (p = 0.007), respectively. Survival rates were similar. CONCLUSIONS Immediate post-EVAR type Ia endoleaks are associated with higher rates of early interventions, late endoleaks and reintervention, which will necessitate strict post-EVAR surveillance. PMID:28017805

The Importance of Mid-to-Late-Life Body Mass Index Trajectories on Late-Life Gait Speed.

PubMed

Windham, B Gwen; Griswold, Michael E; Wang, Wanmei; Kucharska-Newton, Anna; Demerath, Ellen W; Gabriel, Kelley Pettee; Pompeii, Lisa A; Butler, Kenneth; Wagenknecht, Lynne; Kritchevsky, Stephen; Mosley, Thomas H

2017-08-01

Prior studies suggest being overweight may be protective against poor functional outcomes in older adults. Body mass index (BMI, kg/m2) was measured over 25 years across five visits (1987-2011) among Atherosclerosis Risk in Communities Study participants (baseline Visit 1 n = 15,720, aged 45-64 years). Gait speed was measured at Visit 5 ("late-life", aged ≥65 years, n = 6,229). BMI trajectories were examined using clinical cutpoints and continuous mixed models to estimate effects of patterns of BMI change on gait speed, adjusting for demographics and comorbidities. Mid-life BMI (baseline visit; 55% women; 27% black) was associated with late-life gait speed 25 years later; gait speeds were 94.3, 89.6, and 82.1 cm/s for participants with baseline normal BMI (<25), overweight (25 ≤ BMI < 30), and obese (BMI ≥ 30) (p < .001). In longitudinal analyses, late-life gait speeds were 96.9, 88.8, and 81.3 cm/s for participants who maintained normal, overweight, and obese weight status, respectively, across 25 years (p < .01). Increasing BMI over 25 years was associated with poorer late-life gait speeds; a 1%/year BMI increase for a participant with a baseline BMI of 22.5 (final BMI 28.5) was associated with a 4.6-cm/s (95% confidence interval: -7.0, -1.8) slower late-life gait speed than a participant who maintained a baseline BMI of 22.5. Being overweight in older age was not protective of mobility function. Maintaining a normal BMI in mid- and late-life may help preserve late-life mobility. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Late Treatment of Syndesmotic Injuries.

PubMed

Swords, Michael P; Sands, Andrew; Shank, John R

2017-03-01

Normal syndesmosis anatomy and alignment are essential to ankle function. Although injuries to the syndesmosis are common with ankle injuries, accurate diagnosis and reduction continue to be a challenge. Late reconstruction for syndesmosis is reviewed. A surgical technique for late reconstruction is outlined in detail. Copyright © 2016 Elsevier Inc. All rights reserved.

Evolving user needs and late-mover advantage

PubMed Central

Querbes, Adrien; Frenken, Koen

2016-01-01

We propose a generalized NK-model of late-mover advantage where late-mover firms leapfrog first-mover firms as user needs evolve over time. First movers face severe trade-offs between the provision of functionalities in which their products already excel and the additional functionalities requested by users later on. Late movers, by contrast, start searching when more functionalities are already known and typically come up with superior product designs. We also show that late-mover advantage is more probable for more complex technologies. Managerial implications follow. PMID:28596705

Rodents and lagomorphs (Mammalia) from the Hemphillian (late Miocene) of Utah

USGS Publications Warehouse

Korth, W.W.; De Blieux, D. D.

2010-01-01

Four species of rodents (two heteromyids and two cricetids) and one lagomorph are identified from the late Tertiary Sevier River Formation of Utah. The heteromyids include a new genus and species of heteromyine, Metaliomys sevierensis, which is intermediate in morphology between the Clarendonian and early Hemphillian Diprionomys Kellogg and the extant genera Liomys and Heteromys. A single specimen is referred to Diprionomys sp., cf. D. minimus (Kellogg). The cricetid Paronychomys lemredfieldi Jacobs is known from the Hemphillian of Arizona. The second cricetid is referred to a new genus Basirepomys. Peromyscus pliocenicus Wilson from the Hemphillian of California is designated as the type species of the new genus, to which the new species B. robertsi from Utah is referred. Basirepomys is viewed as intermediate between Peromyscus and the basal neotomyine Repomys May from the late Hemphillian and Blancan. The only lagomorph in the fauna is Hypolagus vetus (Kellogg). Four of the taxa recognized from the Sevier River Formation (Diprionomys, Paronychomys lemredfieldi, Basirepomys, and Hypolagus vetus) are elsewhere known from the Hemphillian of North America. However, it is not possible at this time to determine whether the fauna is early or late Hemphillian. ?? 2010 by the Society of Vertebrate Paleontology.

Acyl-CoA-Binding Protein ACBP1 Modulates Sterol Synthesis during Embryogenesis1[OPEN

PubMed Central

Hsiao, An-Shan; Xue, Yan

2017-01-01

Fatty acids (FAs) and sterols are primary metabolites that exert interrelated functions as structural and signaling lipids. Despite their common syntheses from acetyl-coenzyme A, homeostatic cross talk remains enigmatic. Six Arabidopsis (Arabidopsis thaliana) acyl-coenzyme A-binding proteins (ACBPs) are involved in FA metabolism. ACBP1 interacts with PHOSPHOLIPASE Dα1 and regulates phospholipid composition. Here, its specific role in the negative modulation of sterol synthesis during embryogenesis is reported. ACBP1, likely in a liganded state, interacts with STEROL C4-METHYL OXIDASE1-1 (SMO1-1), a rate-limiting enzyme in the sterol pathway. Proembryo abortion in the double mutant indicated that the ACBP1-SMO1-1 interaction is synthetic lethal, corroborating with their strong promoter activities in developing ovules. Gas chromatography-mass spectrometry revealed quantitative and compositional changes in FAs and sterols upon overexpression or mutation of ACBP1 and/or SMO1-1. Aberrant levels of these metabolites may account for the downstream defect in lipid signaling. GLABRA2 (GL2), encoding a phospholipid/sterol-binding homeodomain transcription factor, was up-regulated in developing seeds of acbp1, smo1-1, and ACBP1+/−smo1-1 in comparison with the wild type. Consistent with the corresponding transcriptional alteration of GL2 targets, high-oil, low-mucilage phenotypes of gl2 were phenocopied in ACBP1+/−smo1-1. Thus, ACBP1 appears to modulate the metabolism of two important lipid classes (FAs and sterols) influencing cellular signaling. PMID:28500265

Cognitive Impairment and Structural Abnormalities in Late Life Depression with Olfactory Identification Impairment: an Alzheimer's Disease-Like Pattern.

PubMed

Chen, Ben; Zhong, Xiaomei; Mai, Naikeng; Peng, Qi; Wu, Zhangying; Ouyang, Cong; Zhang, Weiru; Liang, Wanyuan; Wu, Yujie; Liu, Sha; Chen, Lijian; Ning, Yuping

2018-03-15

late-life depression with olfactory identification impairment patients were similar to those in Alzheimer's disease; olfactory identification may help identify late-life depression patients who are at a high risk of developing Alzheimer's disease.

Prosodic and Lexical Aspects of Maternal Linguistic Input to Late-Talking Toddlers

ERIC Educational Resources Information Center

D'Odorico, Laura; Jacob, Valentina

2006-01-01

Background: Children who have reached the age of 2 years without having acquired a 50-word vocabulary and/or who use no word combinations are referred to in the literature as "Late Talkers". Research has not yet identified the factors that cause slow development of expressive language; in particular, relatively little research has been carried out…

Combining moderators to identify clinical profiles of patients who will, and will not, benefit from aripiprazole augmentation for treatment resistant late-life major depressive disorder.

PubMed

Smagula, Stephen F; Wallace, Meredith L; Anderson, Stewart J; Karp, Jordan F; Lenze, Eric J; Mulsant, Benoit H; Butters, Meryl A; Blumberger, Daniel M; Diniz, Breno S; Lotrich, Francis E; Dew, Mary Amanda; Reynolds, Charles F

2016-10-01

Personalizing treatment for late-life depression requires identifying and integrating information from multiple factors that influence treatment efficacy (moderators). We performed exploratory moderator analyses using data from a multi-site, randomized, placebo-controlled, double-blind trial of aripiprazole augmentation. Patients (n = 159) aged ≥60 years had major depressive disorder that failed to remit with venlafaxine monotherapy. We examined effect sizes of 39 potential moderators of aripiprazole (vs. placebo) augmentation efficacy using the outcome of percentage reduction in depressive symptom after 12 weeks. We then incorporated information from the individually relevant variables in combined moderators. A larger aripiprazole treatment effect was related to: white race, better physical function, better performance on Trail-Making, attention, immediate, and delayed memory tests, greater psychomotor agitation and suicidality symptoms, and a history of adequate antidepressant pharmacotherapy. A smaller aripiprazole treatment effect was observed in patients with: more pain and more work/activity impairment and libido symptoms. Combining information from race and Trail-Making test performance (base combined moderator (Mb*)) produced a larger effect size (Spearman effect size = 0.29 (95% confidence interval (CI): 0.15, 0.42)) than any individual moderator. Adding other individually relevant moderators in the full combined moderator (Mf*) further improved effect size (Spearman effect size = 0.39 (95% CI: 0.25, 0.52)) and identified a sub-group benefiting more from placebo plus continuation venlafaxine monotherapy than adjunctive aripiprazole. Combining moderators can help clinicians personalize depression treatment. We found the majority of our patients benefited from adjunctive aripiprazole, but a smaller subgroup that is identifiable using clinical measures appeared to benefit more from continuation venlafaxine plus placebo. Copyright © 2016 Elsevier Ltd

National Institutes of Health Blood and Marrow Transplant Late Effects Initiative: The Healthcare Delivery Working Group Report

PubMed Central

Hashmi, Shahrukh K; Bredeson, Christopher; Duarte, Rafael F; Farnia, Stephanie; Ferrey, Susan; Fitzhugh, Courtney; Flowers, Mary ED; Gajewski, James; Gastineau, Dennis; Greenwald, Melissa; Jagasia, Madan; Martin, Patricia; Rizzo, J Douglas; Schmit-Pokorny, Kimberly; Majhail, Navneet S

2016-01-01

Hematopoietic cell transplantation (HCT) survivors are at risk for development of late complications and require lifelong monitoring for screening and prevention of late effects. There is an increasing appreciation of the issues related to healthcare delivery and coverage that are faced by HCT survivors. The 2016 National Institutes of Health Blood and Marrow Transplant Late Effects Initiative included an international and broadly representative Healthcare Delivery Working Group that was tasked with identifying research gaps pertaining to healthcare delivery and to identify initiatives that may yield a better understanding of the long-term value and costs of care for HCT survivors. There is a paucity of literature in this area. Critical areas in need of research include pilot studies of novel and information technology supported models of care delivery and coverage for HCT survivors along with development and validation of instruments that capture patient reported outcomes. Investment in infrastructure to support this research such as linkage of databases including electronic health records and routine inclusion of endpoints that will inform analyses focused around care delivery and coverage are required. PMID:27713091

Predictors of Severe Acute and Late Toxicities in Patients With Localized Head-and-Neck Cancer Treated With Radiation Therapy

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

Meyer, Francois, E-mail: francois.meyer@chuq.qc.ca; Fortin, Andre; Wang, Chang Shu

2012-03-15

Purpose: Radiation therapy (RT) causes acute and late toxicities that affect various organs and functions. In a large cohort of patients treated with RT for localized head and neck cancer (HNC), we prospectively assessed the occurrence of RT-induced acute and late toxicities and identified characteristics that predicted these toxicities. Methods and Materials: We conducted a randomized trial among 540 patients treated with RT for localized HNC to assess whether vitamin E supplementation could improve disease outcomes. Adverse effects of RT were assessed using the Radiation Therapy Oncology Group Acute Radiation Morbidity Criteria during RT and one month after RT, andmore » the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme at six and 12 months after RT. The most severe adverse effect among the organs/tissues was selected as an overall measure of either acute or late toxicity. Grade 3 and 4 toxicities were considered as severe. Stepwise multivariate logistic regression models were used to identify all independent predictors (p < 0.05) of acute or late toxicity and to estimate odds ratios (OR) for severe toxicity with their 95% confidence intervals (CI). Results: Grade 3 or 4 toxicity was observed in 23% and 4% of patients, respectively, for acute and late toxicity. Four independent predictors of severe acute toxicity were identified: sex (female vs. male: OR = 1.72, 95% confidence interval [CI]: 1.06-2.80), Karnofsky Performance Status (OR = 0.67 for a 10-point increment, 95% CI: 0.52-0.88), body mass index (above 25 vs. below: OR = 1.88, 95% CI: 1.22-2.90), TNM stage (Stage II vs. I: OR = 1.91, 95% CI: 1.25-2.92). Two independent predictors were found for severe late toxicity: female sex (OR = 3.96, 95% CI: 1.41-11.08) and weight loss during RT (OR = 1.26 for a 1 kg increment, 95% CI: 1.12-1.41). Conclusions: Knowledge of these predictors easily collected in a clinical setting

The Conformation of a Plasma Membrane-Localized Somatic Embryogenesis Receptor Kinase Complex Is Altered by a Potato Aphid-Derived Effector1[OPEN

PubMed Central

Peng, Hsuan-Chieh; Hicks, Glenn R.; Kaloshian, Isgouhi

2016-01-01

Somatic embryogenesis receptor kinases (SERKs) are transmembrane receptors involved in plant immunity. Tomato (Solanum lycopersicum) carries three SERK members. One of these, SlSERK1, is required for Mi-1.2-mediated resistance to potato aphids (Macrosiphum euphorbiae). Mi-1.2 encodes a coiled-coil nucleotide-binding leucine-rich repeat protein that in addition to potato aphids confers resistance to two additional phloem-feeding insects and to root-knot nematodes (Meloidogyne spp.). How SlSERK1 participates in Mi-1.2-mediated resistance is unknown, and no Mi-1.2 cognate pest effectors have been identified. Here, we study the mechanistic involvement of SlSERK1 in Mi-1.2-mediated resistance. We show that potato aphid saliva and protein extracts induce the Mi-1.2 defense marker gene SlWRKY72b, indicating that both saliva and extracts contain a Mi-1.2 recognized effector. Resistant tomato cultivar Motelle (Mi-1.2/Mi-1.2) plants overexpressing SlSERK1 were found to display enhanced resistance to potato aphids. Confocal microscopy revealed that Mi-1.2 localizes at three distinct subcellular compartments: the plasma membrane, cytoplasm, and nucleus. Coimmunoprecipitation experiments in these tomato plants and in Nicotiana benthamiana transiently expressing Mi-1.2 and SlSERK1 showed that Mi-1.2 and SlSERK1 colocalize only in a microsomal complex. Interestingly, bimolecular fluorescence complementation analysis showed that the interaction of Mi-1.2 and SlSERK1 at the plasma membrane distinctively changes in the presence of potato aphid saliva, suggesting a model in which a constitutive complex at the plasma membrane participates in defense signaling upon effector binding. PMID:27208261

The structure of late-life depressive symptoms across a 20-year span: a taxometric investigation.

PubMed

Holland, Jason M; Schutte, Kathleen K; Brennan, Penny L; Moos, Rudolf H

2010-03-01

Past studies of the underlying structure of depressive symptoms have yielded mixed results, with some studies supporting a continuous conceptualization and others supporting a categorical one. However, no study has examined this research question with an exclusively older adult sample, despite the potential uniqueness of late-life depressive symptoms. In the present study, the underlying structure of late-life depressive symptoms was examined among a sample of 1,289 individuals across 3 waves of data collection spanning 20 years. The authors employed a taxometric methodology using indicators of depression derived from the Research Diagnostic Criteria (R. L. Spitzer, J. Endicott, & E. Robins, 1978). Maximum eigenvalue analyses and inchworm consistency tests generally supported a categorical conceptualization and identified a group that was primarily characterized by thoughts about death and suicide. However, compared to a categorical depression variable, depressive symptoms treated continuously were generally better predictors of relevant criterion variables. These findings suggest that thoughts of death and suicide may characterize a specific type of late-life depression, yet a continuous conceptualization still typically maximizes the predictive utility of late-life depressive symptoms.

Curcumin alleviates ischemia reperfusion-induced late kidney fibrosis through the APPL1/Akt signaling pathway.

PubMed

Hongtao, Chen; Youling, Fan; Fang, Huang; Huihua, Peng; Jiying, Zhong; Jun, Zhou

2018-05-09

As a major cause of renal failure, transient renal ischemia and reperfusion induce both acute kidney injury and late fibrosis, which are the common pathological manifestations of end-stage renal disease. Curcumin is a biologically active polyphenolic compound found in turmeric. Increasing evidence has demonstrated that curcumin has a protective action against renal fibrosis, whereas mechanisms underlying the anti-fibrosis role of curcumin remain poorly defined. Here, we found that APPL1, an important intracellular binding partner for AdipoR, was involved in the pathogenesis of acute injury or fibrosis and was significantly upregulated by curcumin in a mouse model of ischemia reperfusion-induced late kidney fibrosis. Moreover, Akt signaling was the specific signaling pathway identified downstream of APPL1 in the pathogenesis of fibrosis. Our in vitro experiment demonstrated that curcumin alleviates ischemia reperfusion-induced late kidney fibrosis via the APPL1/Akt pathway. These data are helpful for understanding the anti-fibrosis mechanism of curcumin in the pathogenesis of AKI-induced late fibrosis. © 2018 Wiley Periodicals, Inc.

The fallacy of late-life divorce in Japan.

PubMed

Kumagai, Fumie

2006-01-01

Late-life divorces in Japan, that is, divorces by couples with more than 20 years' duration of marriage at the time of divorce, have become increasingly conspicuous since in the mid-1990s. However, an increase in the number of late-life divorces is not the same as an increase in the divorce rate. That is, the conspicuous phenomenon of late-life divorces may not reflect the true nature of the institution of divorce. It may be a fallacy of late-life divorce in Japan today. This is the starting point of the present study. Five major findings have emerged. First, late-life divorces did increase dramatically over the recent past. Second, late-life divorces will continue to increase after 2007, when the new old-age pension division scheme for couples who pursue divorce will be in effect. Third, the increment in late-life divorce cases is due primarily to the baby-boomers born between 1947 and 1949 who are pursuing such late-life divorces. Fourth, as the duration of marriage increases, Japanese married couples are less inclined to pursue divorce. Fifth, the reasons for late-life divorces differ from those expressed for divorces in general. It is hoped that these findings will provide valuable insights for Japanese couples married for many years who may wish to reconsider and to reconstruct their marital relationship for the better.

Lipidomics: the function of vital lipids in embryogenesis preventing autism spectrum disorders, treating sterile inflammatory diatheses with a lymphopoietic central nervous system component.

PubMed

Tallberg, Thomas; Dabek, Jan; Hallamaa, Raija; Atroshi, Faik

2011-01-01

The central role performed by billions of vital central nervous system (CNS) lipids "lipidomics" in medical physiology is usually overlooked. A metabolic deficiency embracing these vital lipids can form the aetiology for a variety of diseases. CNS lipids regulate embryogenesis, cell induction, mental balance by preventing autism spectrum disorders, depression, burn-out syndromes like posttraumatic stress disease PTSD, by guarding normal immunity, treating sterile inflammatory diatheses with a titanium containing lymphopoietic CNS lipid component. The propaganda driving for unphysiological fat-free diets is dangerous and can cause serious health problems for a whole generation. This article presents a broad list of various mental and motor bodily functions of which the healthy function depends on these vital CNS lipids. A rigorous fat-free diet can provoke these metabolic lipid deficiencies but they can fortunately be compensated by dietary supplementation, but not by pharmacologic treatment.

Late-Type Membership of the Open Cluster NGC 2232

NASA Technical Reports Server (NTRS)

Orban, Chris; Patten, Brian

2004-01-01

NGC 2232 is one of the nearest open clusters (approx.360 pc) with an age of approx.25 Myr. This places it in the unique position to study the transition from T Tauri activity to the Zero Age Main Sequence. In order for those studies to begin, late-type members must be identified for the cluster. X-ray observations combined with ground-based photometry and spectroscopy offers the best way to accomplish this goal. We present photometry in the VRI bands, 2MASS near-infrared measurements in the J, H , Ks bands and spectra for the suspected optical counterparts to the X-ray sources in the field of NGC 2232. 46 candidate members were identified through these efforts ranging from F5 to M5.

Waterlogging effects on growth and yield components in late-planted soybean.

PubMed

Linkemer, G; Board, J E; Musgrave, M E

1998-01-01

A major agronomic problem in the southeastern USA is low yield of late-planted soybean [Glycine max (L.) Merr.]. This problem is aggravated by the adverse effect of waterlogging on crop growth. Our objectives were to identify soybean growth stages sensitive to waterlogging; identify yield components and physiological parameters explaining yield losses induced by waterlogging; and determine the extent of yield losses induced by waterlogging under natural field conditions. Greenhouse and field studies were conducted during 1993 and 1994 near Baton Rouge, LA, (30 degrees N Lat) on a Commerce silt loam. Waterlogging tolerance was assessed in cultivar Centennial (Maturity Group VI) at three vegetative and five reproductive growth stages by maintaining the water level at the soil surface in a greenhouse study. Using the same cultivar, we evaluated the effect of drainage in the field for late-planted soybean. Rain episodes determined the timing of waterlogging; redox potential and oxygen concentration of the soil were used to quantify the intensity of waterlogging stress. Results of the greenhouse study indicated that the early vegetative period (V2) and the early reproductive stages (R1, R3, and R5) were most sensitive to waterlogging. Three to 5 cm of rain per day falling on poorly drained soil was sufficient to reduce crop growth rate, resulting in a yield decline from 2453 to 1550 kg ha-1. Yield loss in both field and greenhouse studies was induced primarily by decreased pod production resulting from fewer pods per reproductive node. In conclusion, waterlogging was determined to be an important stress for late-planted soybean in high rainfall areas such as the Gulf Coast Region.

The chromatin remodeler chd5 is necessary for proper head development during embryogenesis of Danio rerio.

PubMed

Bishop, Brett; Ho, Kwok Ki; Tyler, Kim; Smith, Amanda; Bonilla, Sylvia; Leung, Yuk Fai; Ogas, Joe

2015-08-01

The chromatin remodeler CHD5 plays a critical role in tumor suppression and neurogenesis in mammals. CHD5 contributes to gene expression during neurogenesis, but there is still much to learn regarding how this class of remodelers contributes to differentiation and development. CHD5 remodelers are vertebrate-specific, raising the prospect that CHD5 plays one or more conserved roles in this phylum. Expression of chd5 in adult fish closely mirrors expression of CHD5 in adult mammals. Knockdown of Chd5 during embryogenesis suggests new roles for CHD5 remodelers based on resulting defects in craniofacial development including reduced head and eye size as well as reduced cartilage formation in the head. In addition, knockdown of Chd5 results in altered expression of neural markers in the developing brain and eye as well as a profound defect in differentiation of dopaminergic amacrine cells. Recombinant zebrafish Chd5 protein exhibits nucleosome remodeling activity in vitro, suggesting that it is the loss of this activity that contributes to the observed phenotypes. Our studies indicate that zebrafish is an appropriate model for functional characterization of CHD5 remodelers in vertebrates and highlight the potential of this model for generating novel insights into the role of this vital class of remodelers. Copyright © 2015. Published by Elsevier B.V.

Enhanced induction of microspore embryogenesis after n-butanol treatment in wheat (Triticum aestivum L.) anther culture.

PubMed

Soriano, M; Cistué, L; Castillo, A M

2008-05-01

The aim of this study was the improvement of embryo production in wheat anther culture. Three butanol alcohols, n-butanol, sec-butanol and tert-butanol, were evaluated for their effect on microspore embryogenesis in two spring cultivars of wheat, Pavon and Caramba. Application of n-butanol, at 0.1 and 0.2% (v/v) in the induction media for 5 h, highly improved embryo production in both cultivars. Sec- and tert-butanol performed similarly to control plates. Regeneration ability was unaffected by any butyl-alcohol treatment. As a consequence of the higher embryo production after n-butanol treatment, the number of green regenerated plants increased up to five times in cultivar Pavon and up to three times in cultivar Caramba. The percentage of green plants was improved or unaffected by the treatment. Doubled haploid plant production was between 2 and 4 times higher after n-butanol treatment than in control plates. Therefore, n-butanol was successfully applied in the production of wheat doubled haploids. This primary alcohol is known as an activator of phospholipase D and has been previously reported to disrupt cortical microtubules and detach them from the plasma membrane in plants. Its effects on androgenetic induction could confirm the importance of microtubule regulation in plant cell fate, specifically in microspore development. A possible implication of phospholipase D is discussed.

Application of carbon isotope stratigraphy to late miocene shallow marine sediments, new zealand.

PubMed

Loutit, T S; Kennett, J P

1979-06-15

A distinct (0.5 per mil) carbon-13/carbon-12 isotopic shift in the light direction has been identified in a shallow marine sedimentary sequence of Late Miocene age at Blind River, New Zealand, and correlated with a similar shift in Late Miocene Deep Sea Drilling Project sequences throughout the Indo-Pacific. A dated piston core provides an age for the shift of 6.2 +/- 0.1 million years. Correlations based on the carbon isotopic change require a revision of the previously established magnetostratigraphy at Blind River. The carbon shift at Blind River occurs between 6.2 and 6.3 +/- 0.1 million years before present. A new chronology provides an age for the evolutionary first appearance datum of Globorotalia conomiozea at 6.1 +/- 0.1 million years, the beginning of a distinct latest Miocene cooling event associated with the Kapitean stage at 6.2 +/- 0.1 million years, and the beginning of a distinct shallowing of water depths at 6.1 +/- 0.1 million years. The Miocene-Pliocene boundary as recognized in New Zealand is now dated at 5.3 +/- 0.1 million years. Extension of carbon isotope stratigraphy to other shallow Late Miocene sequences should provide an important datum for international correlation of Late Miocene shallow and deep marine sequences.

Do negative emotions expressed during follow-up consultations with adolescent survivors of childhood cancer reflect late effects?

PubMed

Mellblom, Anneli V; Ruud, Ellen; Loge, Jon Håvard; Lie, Hanne C

2017-11-01

To explore whether negative emotions expressed by adolescent cancer survivors during follow-up consultations were associated with potential late effects (persisting disease or treatment-related health problems). We video-recorded 66 follow-up consultations between 10 pediatricians and 66 adolescent survivors of leukemia, lymphoma or stem-cell transplantations. In transcripts of the recordings, we identified utterances coded as both 1) expressions of negative emotions (VR-CoDES), and 2) late effect-related discussions. Principles of thematic content analysis were used to investigate associations between the two. Of the 66 video-recorded consultations, 22 consultations contained 56 (49%) utterances coded as both emotional concerns and discussions of potential late effects. Negative emotions were most commonly associated with late effects such as fatigue ("I'm struggling with not having energy"), psychosocial distress ("When I touch this (scar) I become nauseous"), pain ("I'm wondering how long I am going to have this pain?"), and treatment-related effects on physical appearance ("Am I growing?"). Negative emotions expressed by adolescent cancer survivors during follow-up consultations were frequently associated with potential late effects. These late effects were not the medically most serious ones, but reflected issues affecting the adolescents' daily life. Eliciting and exploring patients' emotional concerns serve as means to obtain clinically relevant information regarding potential late effect and to provide emotional support. Copyright © 2017 Elsevier B.V. All rights reserved.

Incidence of cognitively defined late-onset Alzheimer's dementia subgroups from a prospective cohort study.

PubMed

Crane, Paul K; Trittschuh, Emily; Mukherjee, Shubhabrata; Saykin, Andrew J; Sanders, R Elizabeth; Larson, Eric B; McCurry, Susan M; McCormick, Wayne; Bowen, James D; Grabowski, Thomas; Moore, Mackenzie; Bauman, Julianna; Gross, Alden L; Keene, C Dirk; Bird, Thomas D; Gibbons, Laura E; Mez, Jesse

2017-12-01

There may be biologically relevant heterogeneity within typical late-onset Alzheimer's dementia. We analyzed cognitive data from people with incident late-onset Alzheimer's dementia from a prospective cohort study. We determined individual averages across memory, visuospatial functioning, language, and executive functioning. We identified domains with substantial impairments relative to that average. We compared demographic, neuropathology, and genetic findings across groups defined by relative impairments. During 32,286 person-years of follow-up, 869 people developed Alzheimer's dementia. There were 393 (48%) with no domain with substantial relative impairments. Some participants had isolated relative impairments in memory (148, 18%), visuospatial functioning (117, 14%), language (71, 9%), and executive functioning (66, 8%). The group with isolated relative memory impairments had higher proportions with ≥ APOE ε4 allele, more extensive Alzheimer's-related neuropathology, and higher proportions with other Alzheimer's dementia genetic risk variants. A cognitive subgrouping strategy may identify biologically distinct subsets of people with Alzheimer's dementia. Copyright © 2017 the Alzheimer's Association. All rights reserved.

Second cancers and late mortality in Australian children treated by allogeneic HSCT for haematological malignancy.

PubMed

Nelson, A S; Ashton, L J; Vajdic, C M; Le Marsney, R E; Daniels, B; Nivison-Smith, I; Wilcox, L; Dodds, A J; O'Brien, T A

2015-02-01

We examined risk of second cancer and late mortality in a population-based Australian cohort of 717 pediatric allogeneic stem cell transplant (HSCT) recipients treated for a malignant disease during 1982-2007. Record linkage with population-based death and cancer registries identified 17 second cancers at a median of 7.9 years post HSCT; thyroid cancer being the most common malignancy (n=8). The cumulative incidence of second cancer was 8.7% at follow-up, and second cancers occurred 20 times more often than in the general population (standardised incidence ratio 20.3, 95% confidence interval (CI)=12.6-32.7). Transplantation using radiation-based conditioning regimens was associated with increased second cancer risk. A total of 367 patients survived for at least 2 years post HSCT and of these 44 (12%) died at a median of 3.1 years after HSCT. Relapse was the most common cause of late mortality (n=32). The cumulative incidence of late mortality was 14.7%. The observed rate of late mortality was 36 times greater than in the matched general population (standardised mortality ratio 35.9, 95% CI=26.7-48.3). Recipients who relapsed or who had radiation-based conditioning regimens were at higher risk of late mortality. Second cancers and late mortality continue to be a risk for pediatric patients undergoing HSCT, and these results highlight the need for effective screening and survivorship programs.

Late style as exile: De/colonising the life course.

PubMed

Hartung, Heike

2016-12-01

In the collection of essays On Late Style, Edward Said reflects on the new idiom achieved by great artists in their work near the end of their lives as "late style." Drawing on Adorno's essay on Beethoven's late style, Said also focuses on the aesthetic aspects of lateness. Defining the late works of artists as "a form of exile," however, Said moves beyond Adorno's aesthetic conception of late style. Highlighting the artist's abandonment of communication with the established social order, who achieves a contradictory, alienated relationship with it instead, Said compares artistic lateness with the experience of the subject in exile. Drawing on the analogy provided by Said, this article argues that the relationship between "self" and "other" in the different theoretical contexts of Postcolonial Studies and Age Studies can be usefully combined in the composite concept of "late style as exile." In order to explore how the concept of lateness correlates with that of exile, this contribution turns to theoretical and autobiographical texts by Edward Said. Copyright © 2016 Elsevier Inc. All rights reserved.

Gratkorn - A new late Middle Miocene vertebrate fauna from Styria (Late Sarmatian, Austria)

NASA Astrophysics Data System (ADS)

Gross, M.; Böhme, M.; Prieto, J.

2009-04-01

Integrated stratigraphic approaches provide precise correlations of global standard stages with regional Paratethys stages. Nevertheless, higher resolution stratigraphic matching of terrestrial deposits remains challenging due to the lack of a practical continental biostratigraphy. The mostly used tool for biostratigraphic correlation of non-marine deposits in the Old World is still the concept of Neogene Mammal-zones (MN-zones). However, at higher biostratigraphic resolution (<1 million years) this concept looses its practicability and has to be replaced by a taxon-range-zonation. To solve this problem a higher number of independently dated small-mammal localities are needed. This is especially crucial for the late Middle to earliest Late Miocene, for which vertebrate faunas in the (Central-)Paratethyan area rare. Recently, a new vertebrate fauna was discovered at the locality Gratkorn (clay pit St. Stefan) just beyond the northwestern margin of the Styrian Basin (Gratkorn Basin; 10 km NW Graz; 15°20'55"E/47°08'15"N). The fauna originates from a c. 0.5 m thick hydromorphic paleosol, underlain by fluvial sands and gravels and topped by c. 15 m thick limnic pelites (Gross, 2008). Sedimentological data as well as the gastropod (Harzhauser et al., 2008) and vertebrate faunas point to a highly structured, more or less vegetated alluvial fan/braided river landscape. Active and abandoned fluvial channels, moist floodplain-soils and ephemeral ponds but also nearby dryer open areas and limestone screes of the up-lifting Palaeozoic basement offered a wide range of habitats. The occurrence of xero- and thermophile terrestrial gastropods and ectothermic vertebrates correspond well with the late Middle/early Late Miocene dry-spell in Central Europe (Böhme et al., 2008). Furthermore, an overall semiarid climate is supported by the development of a calcrete horizon c. 0.6 m below the fossiliferous horizon. The vertebrate remains are irregularly distributed throughout the

Two-stage arterial switch operation: is late ever too late?

PubMed

Al Qethamy, Howaida O; Aizaz, Khawar; Aboelnazar, Saber A R; Hijab, Samina; Al Faraidi, Yahya

2002-09-01

Results of the two-stage arterial switch operation in 49 patients with transposition of the great arteries, performed between January 1995 and September 2000, were reviewed retrospectively. Twenty-one patients had a ventricular septal defect. Anatomical correction was carried out 21.89 +/- 9.86 months after pulmonary artery banding, with or without a modified Blalock-Taussig shunt. Hospital mortality was 8% (4 patients). During follow-up of 30.12 +/- 14.38 months, there was 1 late death and 1 patient required reoperation for pseudoaneurysm of the ascending aorta. Actuarial survival and freedom from reoperation at 5 years were 90% and 97%, respectively. Late anatomic correction (> 6 months) after the preliminary procedure can be performed with an acceptable mortality and morbidity, but undue delay may lead to left ventricular dysfunction, arrhythmias, and new aortic valve regurgitation or subaortic stenosis.

Late INa increases diastolic SR-Ca2+-leak in atrial myocardium by activating PKA and CaMKII

PubMed Central

Fischer, Thomas H.; Herting, Jonas; Mason, Fleur E.; Hartmann, Nico; Watanabe, Saera; Nikolaev, Viacheslav O.; Sprenger, Julia U.; Fan, Peidong; Yao, Lina; Popov, Aron-Frederik; Danner, Bernhard C.; Schöndube, Friedrich; Belardinelli, Luiz; Hasenfuss, Gerd; Maier, Lars S.; Sossalla, Samuel

2015-01-01

Aims Enhanced cardiac late Na current (late INa) and increased sarcoplasmic reticulum (SR)-Ca2+-leak are both highly arrhythmogenic. This study seeks to identify signalling pathways interconnecting late INa and SR-Ca2+-leak in atrial cardiomyocytes (CMs). Methods and results In murine atrial CMs, SR-Ca2+-leak was increased by the late INa enhancer Anemonia sulcata toxin II (ATX-II). An inhibition of Ca2+/calmodulin-dependent protein kinase II (Autocamide-2-related inhibitory peptide), protein kinase A (H89), or late INa (Ranolazine or Tetrodotoxin) all prevented ATX-II-dependent SR-Ca2+-leak. The SR-Ca2+-leak induction by ATX-II was not detected when either the Na+/Ca2+ exchanger was inhibited (KBR) or in CaMKIIδc-knockout mice. FRET measurements revealed increased cAMP levels upon ATX-II stimulation, which could be prevented by inhibition of adenylyl cyclases (ACs) 5 and 6 (NKY 80) but not by inhibition of phosphodiesterases (IBMX), suggesting PKA activation via an AC-dependent increase of cAMP levels. Western blots showed late INa-dependent hyperphosphorylation of CaMKII as well as PKA target sites at ryanodine receptor type-2 (-S2814 and -S2808) and phospholamban (-Thr17, -S16). Enhancement of late INa did not alter Ca2+-transient amplitude or SR-Ca2+-load. However, upon late INa activation and simultaneous CaMKII inhibition, Ca2+-transient amplitude and SR-Ca2+-load were increased, whereas PKA inhibition reduced Ca2+-transient amplitude and load and additionally slowed Ca2+ elimination. In atrial CMs from patients with atrial fibrillation, inhibition of late INa, CaMKII, or PKA reduced the SR-Ca2+-leak. Conclusion Late INa exerts distinct effects on Ca2+ homeostasis in atrial myocardium through activation of CaMKII and PKA. Inhibition of late INa represents a potential approach to attenuate CaMKII activation and decreases SR-Ca2+-leak in atrial rhythm disorders. The interconnection with the cAMP/PKA system further increases the antiarrhythmic potential of late

Responses to highly active antiretroviral therapy and clinical events in patients with a low CD4 cell count: late presenters vs. late starters.

PubMed

Waters, L; Fisher, M; Anderson, J; Wood, C; Delpech, V; Hill, T; Walsh, J; Orkin, C; Bansi, L; Gompels, M; Phillips, A; Johnson, M; Gilson, R; Easterbrook, P; Leen, C; Porter, K; Gazzard, B; Sabin, C

2011-05-01

We investigated whether adverse responses to highly active antiretroviral therapy (HAART) associated with late HIV presentation are secondary to low CD4 cell count per se or other confounding factors. A longitudinal analysis of the UK Collaborative HIV Cohort (CHIC) Study of individuals starting HAART in 1998-2007 was carried out, comparing late presenters (presenting/starting HAART at a CD4 count <200 cells/μL) with late starters (presenting at a CD4 count>350 cells/μL; starting HAART at a CD4 count<200 cells/μL), using 'ideal starters' (presenting at a CD4 count>350 cells/μL; starting HAART at a CD4 count of 200-350 cells/μL) as a comparator. Virological, immunological and clinical (new AIDS event/death) outcomes at 48 and 96 weeks were analysed, with the analysis being limited to those remaining on HAART for>3 months. A total of 4978 of 9095 individuals starting first-line HAART with HIV RNA>500 HIV-1 RNA copies/mL were included in the analysis: 2741 late presenters, 947 late starters and 1290 ideal starters. Late presenters were more commonly female, heterosexual and Black African. Most started nonnucleoside reverse transcriptase inhibitors (NNRTIs); 48-week virological suppression was similar in late presenters and starters (and marginally lower than in ideal starters); by week 96 differences were reduced and nonsignificant. The median CD4 cell count increase in late presenters was significantly lower than that in late starters (weeks 48 and 96). During year 1, new clinical events were more frequent for late presenters [odds ratio (OR) 2.04; 95% confidence interval (CI) 1.19-3.51; P=0.01]; by year 2, event rates were similar in all groups. Amongst patients who initiate, and remain on, HAART, late presentation is associated with lower rates of virological suppression, blunted CD4 cell count increases and more clinical events compared with late starters in year 1, but similar clinical and immunological outcomes by year 2 to those of both late and ideal

Genome-wide analyses of late pollen-preferred genes conserved in various rice cultivars and functional identification of a gene involved in the key processes of late pollen development.

PubMed

Moon, Sunok; Oo, Moe Moe; Kim, Backki; Koh, Hee-Jong; Oh, Sung Aeong; Yi, Gihwan; An, Gynheung; Park, Soon Ki; Jung, Ki-Hong

2018-04-23

Understanding late pollen development, including the maturation and pollination process, is a key component in maintaining crop yields. Transcriptome data obtained through microarray or RNA-seq technologies can provide useful insight into those developmental processes. Six series of microarray data from a public transcriptome database, the Gene Expression Omnibus of the National Center for Biotechnology Information, are related to anther and pollen development. We performed a systematic and functional study across the rice genome of genes that are preferentially expressed in the late stages of pollen development, including maturation and germination. By comparing the transcriptomes of sporophytes and male gametes over time, we identified 627 late pollen-preferred genes that are conserved among japonica and indica rice cultivars. Functional classification analysis with a MapMan tool kit revealed a significant association between cell wall organization/metabolism and mature pollen grains. Comparative analysis of rice and Arabidopsis demonstrated that genes involved in cell wall modifications and the metabolism of major carbohydrates are unique to rice. We used the GUS reporter system to monitor the expression of eight of those genes. In addition, we evaluated the significance of our candidate genes, using T-DNA insertional mutant population and the CRISPR/Cas9 system. Mutants from T-DNA insertion and CRISPR/Cas9 systems of a rice gene encoding glycerophosphoryl diester phosphodiesterase are defective in their male gamete transfer. Through the global analyses of the late pollen-preferred genes from rice, we found several biological features of these genes. First, biological process related to cell wall organization and modification is over-represented in these genes to support rapid tube growth. Second, comparative analysis of late pollen preferred genes between rice and Arabidopsis provide a significant insight on the evolutional disparateness in cell wall biogenesis

Paternal and maternal factors in preimplantation embryogenesis: interaction with the biochemical environment.

PubMed

Ménézo, Yves J R

2006-05-01

Paternal effect on embryonic development occurs as early as fertilization. Incorrect formation of the spermatozoon due to centrosome defects and abnormal concentrations of any components involved in the activation process lead to failure immediately or in the subsequent cell cycles. Sperm chromosomal abnormalities result in early embryo developmental arrests. Generally poor spermatozoa lead to poor blastocyst formation. Sperm DNA fragmentation may impair even late post-implantation development. The DNA repair capacity of the oocytes is of major importance. Early preimplantation development, i.e. until maternal to zygotic transition, is maternally driven. Maternal mRNAs and proteins are of major importance, as there is an unavoidable turnover of these reserves. Polyadenylation of these mRNAs is precisely controlled, in order to avoid too early or too late transcription and translation of the housekeeping genes. An important set of maternal regulations, such as DNA stability, transcriptional regulation and protection against oxidative stress, are impaired by age. The embryo biochemical endogenous pool is very important and may depend upon the environment, i.e. the culture medium. Paternal, maternal and environmental factors are unavoidable parameters; they become evident when age impairs oocyte quality.

Expression of Msx-2 during development, regeneration, and wound healing in axolotl limbs.

PubMed

Carlson, M R; Bryant, S V; Gardiner, D M

1998-12-15

Msx genes are transcription factors that are expressed during embryogenesis of developing appendages in regions of epithelial-mesenchymal interactions. Various lines of evidence indicate that these genes function to maintain embryonic tissues in an undifferentiated, proliferative state. We have identified the axolotl homolog of Msx-2, and investigated its expression during limb development, limb regeneration, and wound healing. As in limb buds of higher vertebrates, axolotl Msx-2 is expressed in the apical epidermis and mesenchyme; however, its expression domain is more extensive, reflecting the broader region of the apical epidermal cap in amphibians. Msx-2 expression is downregulated at late stages of limb development, but is reexpressed within one hour after limb amputation. Msx-2 is also reexpressed during wound healing, and may be essential in the early stages of initiation of the limb regeneration cascade.

Management of Immediate Post-Endovascular Aortic Aneurysm Repair Type Ia Endoleaks and Late Outcomes.

PubMed

AbuRahma, Ali F; Hass, Stephen M; AbuRahma, Zachary T; Yacoub, Michael; Mousa, Albeir Y; Abu-Halimah, Shadi; Dean, L Scott; Stone, Patrick A

2017-04-01

Post-endovascular aortic aneurysm repair (EVAR) endoleaks and the need for reintervention are challenging. Additional endovascular treatment is advised for type Ia endoleaks detected on post-EVAR completion angiogram. This study analyzed management and late outcomes of these endoleaks. This was a retrospective review of prospectively collected data from EVAR patients during a 10-year period. All post-EVAR type Ia endoleaks on completion angiogram were identified (group A) and their early (30-day) and late outcomes were compared with outcomes of patients without endoleaks (group B). Kaplan-Meier analysis was used for survival analysis, sac expansion, late type Ia endoleak, and reintervention. Seventy-one of 565 (12.6%) patients had immediate post-EVAR type Ia endoleak. Early intervention (proximal aortic cuffs and/or stenting) was used in 56 of 71 (79%) in group A vs 31 of 494 (6%) in group B (p < 0.0001). Late type Ia endoleak was noted in 9 patients (13%) in group A at a mean follow-up of 28 months vs 10 patients (2%) in group B at a mean follow-up of 32 months (p < 0.0001). Late sac expansion and reintervention rates were 9% and 10% for group A vs 5% and 3% for group B (p = 0.2698 and p = 0.0198), respectively. Freedom rates from late type Ia endoleaks at 1, 3, and 5 years for group A were 88%, 85%, and 80% vs 98%, 98%, and 96% for group B (p < 0.001); and for late intervention, were 94%, 92%, and 77% for group A, and 99%, 97%, and 95% for group B (p = 0.007), respectively. Survival rates were similar. Immediate post-EVAR type Ia endoleaks are associated with higher rates of early interventions, late endoleaks and reintervention, which will necessitate strict post-EVAR surveillance. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Early- versus Late-Onset Dysthymia

PubMed Central

Sansone, Lori A.

2009-01-01

In the current Diagnostic and Statistical Manual of Mental Disorders, dysthymic disorder is categorized as either early-onset or late-onset, based upon the emergence of symptoms before or after the age of 21, respectively. Does this diagnostic distinction have any meaningful clinical implications? In this edition of The Interface, we present empirical studies that have, within a single study, compared individuals with early-versus late-onset dysthymia. In this review, we found that, compared to those with late-onset dysthymia, early-onset patients are more likely to harbor psychiatric comorbidity both on Axis I and II, exhibit less psychological resilience, and have more prominent family loadings for mood disorders. These findings suggest that this distinction is meaningful and that the early-onset subtype of dysthymia is more difficult to effectively treat. PMID:20049145

Psychosocial Adjustment and Family Relationships: A Typology of Italian Families with a Late Adolescent.

ERIC Educational Resources Information Center

Scabini, Eugenia; Lanz, Margherita; Marta, Elena

1999-01-01

Derived a typology of family relationships for 692 Italian families with at least 1 late adolescent child and studied differences between the 2 extreme types (out of 8 identified) in terms of family satisfaction and adequate functioning. Results show a better communication process in the more satisfied families. (SLD)

A Machine Learning Approach to Identifying Placebo Responders in Late-Life Depression Trials.

PubMed

Zilcha-Mano, Sigal; Roose, Steven P; Brown, Patrick J; Rutherford, Bret R

2018-01-11

Despite efforts to identify characteristics associated with medication-placebo differences in antidepressant trials, few consistent findings have emerged to guide participant selection in drug development settings and differential therapeutics in clinical practice. Limitations in the methodologies used, particularly searching for a single moderator while treating all other variables as noise, may partially explain the failure to generate consistent results. The present study tested whether interactions between pretreatment patient characteristics, rather than a single-variable solution, may better predict who is most likely to benefit from placebo versus medication. Data were analyzed from 174 patients aged 75 years and older with unipolar depression who were randomly assigned to citalopram or placebo. Model-based recursive partitioning analysis was conducted to identify the most robust significant moderators of placebo versus citalopram response. The greatest signal detection between medication and placebo in favor of medication was among patients with fewer years of education (≤12) who suffered from a longer duration of depression since their first episode (>3.47 years) (B = 2.53, t(32) = 3.01, p = 0.004). Compared with medication, placebo had the greatest response for those who were more educated (>12 years), to the point where placebo almost outperformed medication (B = -0.57, t(96) = -1.90, p = 0.06). Machine learning approaches capable of evaluating the contributions of multiple predictor variables may be a promising methodology for identifying placebo versus medication responders. Duration of depression and education should be considered in the efforts to modulate placebo magnitude in drug development settings and in clinical practice. Copyright © 2018 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Economics of Home Monitoring for Apnea in Late Preterm Infants.

PubMed

Montenegro, Brian L; Amberson, Michael; Veit, Lauren; Freiberger, Christina; Dukhovny, Dmitry; Rhein, Lawrence M

2017-01-01

Apnea of prematurity affects a small proportion but large absolute number of late preterm infants, with out-patient management variably utilized despite relative clinical equipoise and potential for improved cost-effectiveness. Over a 5-y period, from 2009 to 2013, infants born at ≥34 weeks gestational age at a level IIIB academic center in Boston, Massachusetts, with discharge-delaying apnea, bradycardia, and desaturation (ABD) events were identified. In-patient costs for discharge-delaying ABD events were compared with hypothetical out-patient management. Out-patient costs took into account 4-10 d of in-patient observation for ABD events before caffeine initiation, 3-5 d of additional in-patient observation before discharge, daily caffeine until 43 weeks corrected gestational age, home pulse oximetry monitoring until 44 weeks corrected gestational age, and consideration of variable readmission rates ranging from 0 to 10%. A total of 425 late preterm and term infants were included in our analysis. Utilization of hypothetical out-patient management resulted in cost savings per eligible patient ranging from $2,422 to $62, dependent upon variable periods of in-patient observation. Sensitivity analysis demonstrated few instances of decreased relative cost-effectiveness. Out-patient management of discharge-delaying ABD events in a late preterm and term population was a cost-effective alternative to prolonged in-patient observation. Copyright © 2017 by Daedalus Enterprises.

Late Holocene and recent rainforest cultural landscapes of North Queensland, Australia

NASA Astrophysics Data System (ADS)

Steinberger, L. M.; Moss, P. T.; Haberle, S.; Cosgrove, R.; Ferrier

2011-12-01

The tropical rainforests of North Queensland, Australia, have been environments of significant human activity for several thousand years. Palaeoecological research has highlighted the long-term effects of Quaternary climate change on these environments at a broad spatial scale, including the expansion of tropical rainforest across the region following the termination of the Last Glacial Maximum. However, identifying the effects of a hunter-gatherer Aboriginal population has been more difficult. Palaeoecological suggestions of Pleistocene Aboriginal burning, based on pollen and charcoal records, have relied on coincident timing with a general narrative of colonisation rather than direct links with archaeological evidence. Current research is explicitly examining the environmental consequences of human activity in North Queensland rainforests by producing local palaeoecological data directly linked to sites and periods of human occupation. Pollen, macrocharcoal and phytolith records have been produced from sites of human activity within the rainforest. Late Holocene Aboriginal occupation of the rainforest is demonstrated to have had significant cultural links to patches of open vegetation that existed within the rainforest. While these patches are likely to have originated as edaphically controlled remnants of Pleistocene vegetation, their expansion and maintenance in the late Holocene is associated with increasing intensity of Aboriginal occupation of the rainforest. Late Holocene Aboriginal rainforest occupation is also contrasted with the historical European colonisation of the rainforest in the late 19th century, which resulted in the most significant environmental changes in the region since the early Holocene. Historical and ethnographic records provide important cultural context for understanding the transition between Aboriginal and European cultural landscapes of the rainforest.

49 CFR 630.6 - Late and incomplete reports.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Late and incomplete reports. 630.6 Section 630.6 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.6 Late and incomplete reports. (a) Late reports...

49 CFR 630.6 - Late and incomplete reports.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Late and incomplete reports. 630.6 Section 630.6 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.6 Late and incomplete reports. (a) Late reports...

49 CFR 630.6 - Late and incomplete reports.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Late and incomplete reports. 630.6 Section 630.6 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.6 Late and incomplete reports. (a) Late reports...

49 CFR 630.6 - Late and incomplete reports.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Late and incomplete reports. 630.6 Section 630.6 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.6 Late and incomplete reports. (a) Late reports...

49 CFR 630.6 - Late and incomplete reports.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Late and incomplete reports. 630.6 Section 630.6 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION NATIONAL TRANSIT DATABASE § 630.6 Late and incomplete reports. (a) Late reports...

Creating a Computer Adaptive Test Version of the Late-Life Function & Disability Instrument

PubMed Central

Jette, Alan M.; Haley, Stephen M.; Ni, Pengsheng; Olarsch, Sippy; Moed, Richard

2009-01-01

Background This study applied Item Response Theory (IRT) and Computer Adaptive Test (CAT) methodologies to develop a prototype function and disability assessment instrument for use in aging research. Herein, we report on the development of the CAT version of the Late-Life Function & Disability instrument (Late-Life FDI) and evaluate its psychometric properties. Methods We employed confirmatory factor analysis, IRT methods, validation, and computer simulation analyses of data collected from 671 older adults residing in residential care facilities. We compared accuracy, precision, and sensitivity to change of scores from CAT versions of two Late-Life FDI scales with scores from the fixed-form instrument. Score estimates from the prototype CAT versus the original instrument were compared in a sample of 40 older adults. Results Distinct function and disability domains were identified within the Late-Life FDI item bank and used to construct two prototype CAT scales. Using retrospective data, scores from computer simulations of the prototype CAT scales were highly correlated with scores from the original instrument. The results of computer simulation, accuracy, precision, and sensitivity to change of the CATs closely approximated those of the fixed-form scales, especially for the 10- or 15-item CAT versions. In the prospective study each CAT was administered in less than 3 minutes and CAT scores were highly correlated with scores generated from the original instrument. Conclusions CAT scores of the Late-Life FDI were highly comparable to those obtained from the full-length instrument with a small loss in accuracy, precision, and sensitivity to change. PMID:19038841

37 CFR 385.4 - Late payments.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 385.4 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS RATES AND TERMS... AND DISTRIBUTING OF PHYSICAL AND DIGITAL PHONORECORDS Physical Phonorecord Deliveries, Permanent Digital Downloads and Ringtones § 385.4 Late payments. A Licensee shall pay a late fee of 1.5% per month...

37 CFR 385.4 - Late payments.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 385.4 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS RATES AND TERMS... AND DISTRIBUTING OF PHYSICAL AND DIGITAL PHONORECORDS Physical Phonorecord Deliveries, Permanent Digital Downloads and Ringtones § 385.4 Late payments. A Licensee shall pay a late fee of 1.5% per month...

37 CFR 385.4 - Late payments.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 385.4 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS RATES AND TERMS... AND DISTRIBUTING OF PHYSICAL AND DIGITAL PHONORECORDS Physical Phonorecord Deliveries, Permanent Digital Downloads and Ringtones § 385.4 Late payments. A Licensee shall pay a late fee of 1.5% per month...

37 CFR 385.4 - Late payments.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 385.4 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS RATES AND TERMS... AND DISTRIBUTING OF PHYSICAL AND DIGITAL PHONORECORDS Physical Phonorecord Deliveries, Permanent Digital Downloads and Ringtones § 385.4 Late payments. A Licensee shall pay a late fee of 1.5% per month...

37 CFR 385.4 - Late payments.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 385.4 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS RATES AND TERMS... AND DISTRIBUTING OF PHYSICAL AND DIGITAL PHONORECORDS Physical Phonorecord Deliveries, Permanent Digital Downloads and Ringtones § 385.4 Late payments. A Licensee shall pay a late fee of 1.5% per month...

40 CFR 209.16 - Late intervention.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Late intervention. 209.16 Section 209.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS... Hearings for Orders Issued Under Section 11(d) of the Noise Control Act § 209.16 Late intervention...

40 CFR 209.16 - Late intervention.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Late intervention. 209.16 Section 209.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS... Hearings for Orders Issued Under Section 11(d) of the Noise Control Act § 209.16 Late intervention...

40 CFR 209.16 - Late intervention.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Late intervention. 209.16 Section 209.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS... Hearings for Orders Issued Under Section 11(d) of the Noise Control Act § 209.16 Late intervention...

40 CFR 209.16 - Late intervention.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Late intervention. 209.16 Section 209.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS... Hearings for Orders Issued Under Section 11(d) of the Noise Control Act § 209.16 Late intervention...

40 CFR 209.16 - Late intervention.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Late intervention. 209.16 Section 209.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS... Hearings for Orders Issued Under Section 11(d) of the Noise Control Act § 209.16 Late intervention...

49 CFR 225.13 - Late reports.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Late reports. 225.13 Section 225.13 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD ACCIDENTS/INCIDENTS: REPORTS CLASSIFICATION, AND INVESTIGATIONS § 225.13 Late reports. Whenever a railroad discovers tha...

Subduction Orogeny and the Late Cenozoic Evolution of the Mediterranean Arcs

NASA Astrophysics Data System (ADS)

Royden, Leigh; Faccenna, Claudio

2018-05-01

The Late Cenozoic tectonic evolution of the Mediterranean region, which is sandwiched between the converging African and European continents, is dominated by the process of subduction orogeny. Subduction orogeny occurs where localized subduction, driven by negative slab buoyancy, is more rapid than the convergence rate of the bounding plates; it is commonly developed in zones of early or incomplete continental collision. Subduction orogens can be distinguished from collisional orogens on the basis of driving mechanism, tectonic setting, and geologic expression. Three distinct Late Cenozoic subduction orogens can be identified in the Mediterranean region, making up the Western Mediterranean (Apennine, external Betic, Maghebride, Rif), Central Mediterranean (Carpathian), and Eastern Mediterranean (southern Dinaride, external Hellenide, external Tauride) Arcs. The Late Cenozoic evolution of these orogens, described in this article, is best understood in light of the processes that govern subduction orogeny and depends strongly on the buoyancy of the locally subducting lithosphere; it is thus strongly related to paleogeography. Because the slow (4–10 mm/yr) convergence rate between Africa and Eurasia has preserved the early collisional environment, and associated tectonism, for tens of millions of years, the Mediterranean region provides an excellent opportunity to elucidate the dynamic and kinematic processes of subduction orogeny and to better understand how these processes operate in other orogenic systems.

Comparison of Parent-Implemented and Clinician-Directed Intervention for Toddlers Identified as Late Talkers: A Literature Review. EBP Briefs. Volume 10, Issue 6

ERIC Educational Resources Information Center

DeVeney, Shari L.; Hagman, Jessica L.

2016-01-01

Clinical Questions: Would a child who is a late talker (P) show greater improvement with parent-implemented intervention models (I) or with clinician-directed intervention models (C) as shown by improvements in expressive language skills (O)? If so, under what circumstances? Method: Literature Review. Study Sources: Education Source, ERIC,…

Predictors of Cigarette Smoking Initiation in Early, Middle, and Late Adolescence.

PubMed

O'Loughlin, Jennifer; O'Loughlin, Erin K; Wellman, Robert J; Sylvestre, Marie-Pierre; Dugas, Erika N; Chagnon, Miguel; Dutczak, Hartley; Laguë, Johanne; McGrath, Jennifer J

2017-09-01

Little is known about age-related differences in risk factors for cigarette smoking initiation. We identified predictors of initiation in early, middle, and late adolescence from among sociodemographic factors, indicators of smoking in the social environment, psychological characteristics, lifestyle indicators, and perceived need for cigarettes. Data were drawn from a longitudinal study of 1,801 children recruited at age 10-11 years from 29 elementary schools in Montreal, Canada. Multivariable logistic regression within a generalized estimating equations framework was used to identify predictors among never smokers across three 2-year windows: age 11-13 years (n = 1,221); age 13-15 years (n = 737); and age 15-17 years (n = 690). Among the 18 risk factors investigated, two differed across age. Friends' smoking, a strong risk factor in early adolescence (odds ratio [95% confidence interval] = 5.78 [3.90-8.58]), lost potency in late adolescence (1.83 [1.31-2.57]). Depressive symptoms, a risk factor in early and middle adolescence (1.60 [1.26-2.02] and 1.92 [1.45-2.54], respectively), were inversely associated in late adolescence (.76 [.58-1.00]). Sex, TV viewing, and weight-related goals were not associated with initiation at any age. All other factors were significant in two or three age groups. Most risk factors for smoking initiation were stable across age. Tobacco control interventions may be robust for risk factors across age groups and may not need adjustment. At all ages, interventions should focus on eliminating smoking in the social environment and on reducing the availability of tobacco products. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Finding of two new radiolarian associations calibrated with ammonoids in the Vaca Muerta Formation (Late Jurassic-Early Cretaceous), Neuquén Basin, Argentina

NASA Astrophysics Data System (ADS)

Vennari, Verónica V.; Pujana, Ignacio

2017-04-01

An association of ammonoids and radiolarians retrieved from a sedimentary section of the Vaca Muerta Formation at Vega de Escalone, Neuquén Basin, Argentina, was analized under a strict stratigraphic control. Nine ammonoid assemblage biozones were identified, indicating an age span from Early Tithonian to Late Berriasian/earlymost Valanginian for the Vaca Muerta Formation at the studied section. In connection to the ammonoid record, two radiolarian faunas were identified and named J3A1 and J3B1. Fauna J3A1, corresponding to the Virgatosphinctes andesensis Biozone, is dominated by nasellarian genera and represents the first Lower Tithonian radiolarian fauna described from the Neuquén Basin. Fauna J3B1, linked to the interval assigned to the Substeueroceras koeneni Biozone (Late Tithonian-Early Berriasian), yields abundant representatives of the Pantanellid Family. The presence of Complexapora kozuri (Kiessling and Zeiss) and Loopus primitivus (Matsuoka and Yao), two important radiolarian primary markers of the Late Jurassic in North America, supports a Late Tithonian age for at least part of the S. koeneni Biozone in the studied area. Nor certain Berriasian radiolarian faunas nor elements of the Vallupinae Family were identified so far at the Vega de Escalone section.

National Institutes of Health Blood and Marrow Transplant Late Effects Initiative: The Healthcare Delivery Working Group Report.

PubMed

Hashmi, Shahrukh K; Bredeson, Christopher; Duarte, Rafael F; Farnia, Stephanie; Ferrey, Susan; Fitzhugh, Courtney; Flowers, Mary E D; Gajewski, James; Gastineau, Dennis; Greenwald, Melissa; Jagasia, Madan; Martin, Patricia; Rizzo, J Douglas; Schmit-Pokorny, Kimberly; Majhail, Navneet S

2017-05-01

Hematopoietic cell transplantation (HCT) survivors are at risk for development of late complications and require lifelong monitoring for screening and prevention of late effects. There is an increasing appreciation of the issues related to healthcare delivery and coverage faced by HCT survivors. The 2016 National Institutes of Health Blood and Marrow Transplant Late Effects Initiative included an international and broadly representative Healthcare Delivery Working Group that was tasked with identifying research gaps pertaining to healthcare delivery and to identify initiatives that may yield a better understanding of the long-term value and costs of care for HCT survivors. There is a paucity of literature in this area. Critical areas in need of research include pilot studies of novel and information technology supported models of care delivery and coverage for HCT survivors along with development and validation of instruments that capture patient-reported outcomes. Investment in infrastructure to support this research, such as linkage of databases including electronic health records and routine inclusion of endpoints that will inform analyses focused around care delivery and coverage, is required. Copyright © 2017 The American Society for Blood and Marrow Transplantation. All rights reserved.

Neurocognitive outcome in young adults born late-preterm.

PubMed

Heinonen, Kati; Lahti, Jari; Sammallahti, Sara; Wolke, Dieter; Lano, Aulikki; Andersson, Sture; Pesonen, Anu-Katriina; Eriksson, Johan G; Kajantie, Eero; Raikkonen, Katri

2018-03-01

This study examined whether late-preterm birth (34+0 to 36+6wks+d gestational age) was associated with neurocognitive deficit in young adulthood, and whether small for gestational age (SGA) birth amplified any adversity. Participants derived from the prospective regional cohort study, the Arvo Ylppö Longitudinal Study (n=786; 398 females, 388 males) (mean age 25y 4mo, SD 8mo), born 1985 to 1986 late-preterm (n=119; 21 SGA, <-2 SD) and at term (37+0 to 41+6wks+d; n=667; 28 SGA) underwent tests of intelligence, executive functioning, attention, and memory, and reported their education. Those born late-preterm scored -3.71 (95% confidence interval [CI] -6.71 to -0.72) and -3.11 (95% CI -6.01 to -0.22) points lower on Full-scale and Verbal IQ than peers born at term. Compared with those born at term and appropriate for gestational age (≥-2 to <2 SD) Full-scale, Verbal, and Performance IQ scores of those born late-preterm and SGA were -9.45 to -11.84 points lower. After adjustments, differences were rendered non-significant, except that scores in Full-scale and Performance IQ remained lower among those born late-preterm and SGA. Late-preterm birth, per se, may not increase the risk of poorer neurocognitive functioning in adulthood. But the double burden of being born late-preterm and SGA seems to increase this risk. Late-preterm birth did not increase the risk of poorer neurocognitive functioning in adulthood. But the double burden of being born late-preterm and being small for gestational age did increase this risk. © 2017 Mac Keith Press.

De novo assembly and characterization of global transcriptome of coconut palm (Cocos nucifera L.) embryogenic calli using Illumina paired-end sequencing.

PubMed

Rajesh, M K; Fayas, T P; Naganeeswaran, S; Rachana, K E; Bhavyashree, U; Sajini, K K; Karun, Anitha

2016-05-01

Production and supply of quality planting material is significant to coconut cultivation but is one of the major constraints in coconut productivity. Rapid multiplication of coconut through in vitro techniques, therefore, is of paramount importance. Although somatic embryogenesis in coconut is a promising technique that will allow for the mass production of high quality palms, coconut is highly recalcitrant to in vitro culture. In order to overcome the bottlenecks in coconut somatic embryogenesis and to develop a repeatable protocol, it is imperative to understand, identify, and characterize molecular events involved in coconut somatic embryogenesis pathway. Transcriptome analysis (RNA-Seq) of coconut embryogenic calli, derived from plumular explants of West Coast Tall cultivar, was undertaken on an Illumina HiSeq 2000 platform. After de novo transcriptome assembly and functional annotation, we have obtained 40,367 transcripts which showed significant BLASTx matches with similarity greater than 40 % and E value of ≤10(-5). Fourteen genes known to be involved in somatic embryogenesis were identified. Quantitative real-time PCR (qRT-PCR) analyses of these 14 genes were carried in six developmental stages. The result showed that CLV was upregulated in the initial stage of callogenesis. Transcripts GLP, GST, PKL, WUS, and WRKY were expressed more in somatic embryo stage. The expression of SERK, MAPK, AP2, SAUR, ECP, AGP, LEA, and ANT were higher in the embryogenic callus stage compared to initial culture and somatic embryo stages. This study provides the first insights into the gene expression patterns during somatic embryogenesis in coconut.

Archean inheritance in zircon from late Paleozoic granites from the Avalon zone of southeastern New England: an African connection

USGS Publications Warehouse

Zartman, R.E.; Don, Hermes O.

1987-01-01

In southeastern New England the Narragansett Pier Granite locally intrudes Carboniferous metasedimentary rocks of the Narragansett basin, and yields a monazite UPb Permian emplacement age of 273 ?? 2 Ma. Zircon from the Narragansett Pier Granite contains a minor but detectable amount of an older, inherited component, and shows modern loss of lead. Zircon from the late-stage, aplitic Westerly Granite exhibits a more pronounced lead inheritance -permitting the inherited component to be identified as Late Archean. Such old relict zircon has not been previously recognized in Proterozoic to Paleozoic igneous rocks in New England, and may be restricted to late Paleozoic rocks of the Avalon zone. We suggest that the Archean crustal component reflects an African connection, in which old Archean crust was underplated to the Avalon zone microplate in the late Paleozoic during collision of Gondwanaland with Avalonia. ?? 1987.

Plakophilin-3 Is Required for Late Embryonic Amphibian Development, Exhibiting Roles in Ectodermal and Neural Tissues

PubMed Central

Munoz, William A.; Kloc, Malgorzata; Hofmann, Ilse; Sater, Amy; Vleminckx, Kris; McCrea, Pierre D.

2012-01-01

The p120-catenin family has undergone a significant expansion during the evolution of vertebrates, resulting in varied functions that have yet to be discerned or fully characterized. Likewise, members of the plakophilins, a related catenin subfamily, are found throughout the cell with little known about their functions outside the desmosomal plaque. While the plakophilin-3 (Pkp3) knockout mouse resulted in skin defects, we find larger, including lethal effects following its depletion in Xenopus. Pkp3, unlike some other characterized catenins in amphibians, does not have significant maternal deposits of mRNA. However, during embryogenesis, two Pkp3 protein products whose temporal expression is partially complimentary become expressed. Only the smaller of these products is found in adult Xenopus tissues, with an expression pattern exhibiting distinctions as well as overlaps with those observed in mammalian studies. We determined that Xenopus Pkp3 depletion causes a skin fragility phenotype in keeping with the mouse knockout, but more novel, Xenopus tailbud embryos are hyposensitive to touch even in embryos lacking outward discernable phenotypes, and we additionally resolved disruptions in certain peripheral neural structures, altered establishment and migration of neural crest, and defects in ectodermal multiciliated cells. The use of two distinct morpholinos, as well as rescue approaches, indicated the specificity of these effects. Our results point to the requirement of Pkp3 in amphibian embryogenesis, with functional roles in a number of tissue types. PMID:22496792

12 CFR 560.33 - Late charges.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Late charges. 560.33 Section 560.33 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY LENDING AND INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.33 Late charges. A Federal savings association may...

Aortic Curvature Is a Predictor of Late Type Ia Endoleak and Migration After Endovascular Aneurysm Repair.

PubMed

Schuurmann, Richte C L; van Noort, Kim; Overeem, Simon P; Ouriel, Kenneth; Jordan, William D; Muhs, Bart E; 't Mannetje, Yannick; Reijnen, Michel; Fioole, Bram; Ünlü, Çağdaş; Brummel, Peter; de Vries, Jean-Paul P M

2017-06-01

To evaluate the association between aortic curvature and other preoperative anatomical characteristics and late (>1 year) type Ia endoleak and endograft migration in endovascular aneurysm repair (EVAR) patients. Eight high-volume EVAR centers contributed 116 EVAR patients (mean age 81±7 years; 103 men) to the study: 36 patients (mean age 82±7 years; 31 men) with endograft migration and/or type Ia endoleak diagnosed >1 year after the initial EVAR and 80 controls without early or late complications. Aortic curvature was calculated from the preoperative computed tomography scan as the maximum and average curvature over 5 predefined aortic segments: the entire infrarenal aortic neck, aneurysm sac, and the suprarenal, juxtarenal, and infrarenal aorta. Other morphological characteristics included neck length, neck diameter, mural neck calcification and thrombus, suprarenal and infrarenal angulation, and largest aneurysm sac diameter. Independent risk factors were identified using backward stepwise logistic regression. Relevant cutoff values for each of the variables in the final regression model were determined with the receiver operator characteristic curve. Logistic regression identified maximum curvature over the length of the aneurysm sac (>47 m -1 ; p=0.023), largest aneurysm sac diameter (>56 mm; p=0.028), and mural neck thrombus (>11° circumference; p<0.001) as independent predictors of late migration and type Ia endoleak. Aortic curvature is a predictor for late type Ia endoleak and endograft migration after EVAR. These findings suggest that aortic curvature is a better parameter than angulation to predict post-EVAR failure and should be included as a hostile neck parameter.