The Distribution of Sulphur in the Differentiating Visceral Cartilage of Xenopus

Development ◽  
1960 ◽  
Vol 8 (1) ◽  
pp. 54-59
Author(s):  
T. S. Okada ◽  
J. L. Sirlin
Keyword(s):  
Embryonic Development ◽  
Neural Crest ◽  
Early Embryo ◽  
Embryonic Tissues ◽  
Early Embryos ◽  
Neural Crest Origin ◽  
Different Tissues

During embryonic development the differentiation of different tissues depends largely on the synthesis of specific substances characteristic of each tissue. From this viewpoint it is of interest to study the uptake of sulphur by the early embryo, especially since the incorporation and retention of this isotope in sulpho-muco-polysaccharides has now been well established by various authors working on fully differentiated tissues (see review by Dziewiatkowski, 1958). So far some work has been done on the distribution of radiosulphate in early embryos (Amprino, 1955 a, b; Friberg & Ringertz, 1956; Johnston & Comar, 1957), but for amphibians in particular no information is yet available. The present paper deals with the incorporation of radiosulphate in various embryonic tissues of Xenopus, in particular in the visceral cartilage of ectomesodermal (neural crest) origin. Embryos of X. laevis in stages 29–47 (Nieuwkoop & Faber, 1956) were used.

Oxidative stress induced by methomyl exposure reduces the quality of early embryo development in mice

Zygote ◽  
2021 ◽  
pp. 1-8
Author(s):  
Daohong He ◽  
Guobo Han ◽  
Xiaomeng Zhang ◽  
Jingyu Sun ◽  
Yongnan Xu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Embryonic Development ◽  
Embryo Development ◽  
Early Embryo ◽  
Early Embryonic Development ◽  
Control Group ◽  
Blastocyst Formation ◽  
Early Embryo Development ◽  
Early Embryos

Summary Methomyl is a widely used carbamate insecticide and environmental oestrogen that has adverse effects on the reproductive system. However, there have been no reports on the effect of methomyl on early embryos in mammals. In this study, we explored the effect of methomyl exposure on the quality of early embryonic development in mice and the possible mechanisms. During in vitro culture, different concentrations of methomyl (10, 20, 30 and 35 μM) were added to mouse zygote medium. The results showed that methomyl had an adverse effect on early embryonic development. Compared with the control group, the addition of 30 μM methomyl significantly reduced the rate of early embryo blastocyst formation. Methomyl exposure can increase oxidative stress and impair mitochondrial function, which may be the cause of blastocyst formation. In addition, we found that methomyl exposure promoted apoptosis and autophagy in mouse blastocysts. The toxic effect of methomyl on early embryos may be the result of oxidative stress induction. Taken together, our results indicate that methomyl can cause embryonic development defects in mice, thereby reducing the quality of early embryo development.

scholarly journals Expression and Potential Role of microRNA-29b in Mouse Early Embryo Development

2015 ◽  
Vol 35 (3) ◽  
pp. 1178-1187 ◽  
Author(s):  
Junqiang Zhang ◽  
Ying Wang ◽  
Xiaoguang Liu ◽  
Shenglin Jiang ◽  
Chun Zhao ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Embryonic Development ◽  
Dna Methyltransferase ◽  
Biological Function ◽  
Expression Patterns ◽  
Early Embryo ◽  
Early Embryonic Development ◽  
Preimplantation Embryos ◽  
Early Embryos

Background/Aims: MicroRNA-29b (miR29b) has been previously identified in early mouse embryos through miRNA microarray analysis. Recent research has indicated that miR29b participates in DNA methylation by regulating DNA methyltransferase 3a/3b (Dnmt3a/3b) expression. However, the expression pattern and biological function of miR29b in mouse preimplantation embryonic development remain unknown. Methods: In this study, we examined the expression patterns of miR29b and Dnmt3a/3b in mouse early embryos at different developmental stages. Subsequently, expression and localization of DNMT3A/3B protein was analyzed in mouse early embryos by immunofluorescence staining. The biological function of miR29b in mouse early embryos was analyzed by microinjection of commercially available miRNA-specific inhibitors and mimics. Results: Our data showed that Dnmt3a/3b mRNA expression is negatively regulated by miR29b in mouse early embryos. Immunofluorescence analysis revealed that DNMT3A/3B protein expression is predominantly localized within the nucleoplasm of embryos. Alterations to the activity of miR29b could change the DNA methylation levels in mouse preimplantation embryos and lead to a developmental blockade, from the morula to the blastocyst stage. Conclusion: These results indicated a role for the miR29b-Dnmt3a/3b-DNA methylation axis in mouse early embryonic development, and we provide evidence that miR29b is indispensable for mouse early embryonic development. This study contributes to a preliminary understanding of the role of miR29b during mouse embryonic development.

scholarly journals Reproductive biology, embryonic development and matrotrophy in the phylactolaemate bryozoan Plumatella casmiana

2021 ◽  
Author(s):  
Julian Bibermair ◽  
Andrew N. Ostrovsky ◽  
Andreas Wanninger ◽  
Thomas Schwaha
Keyword(s):  
Embryonic Development ◽  
Embryo Sac ◽  
The Body ◽  
Transcellular Transport ◽  
Cell Contacts ◽  
Transmission Electron ◽  
Distal Side ◽  
Early Embryos ◽  
Mesoderm Formation ◽  
Cytoplasmic Processes

AbstractBryozoa is a phylum of aquatic, colonial suspension-feeders within the Lophotrochozoa. In the Phylactolaemata embryonic development occurs in an internal brood sac on the body wall accompanied by extraembryonic nutrition. Owing to previous contradictive descriptions, many aspects of their sexual reproduction require restudy. Consequently, this study analyses embryogenesis of the freshwater bryozoan Plumatella casmiana by serial sections, 3D reconstruction and transmission electron microscopy. Early embryos cleave and soon develop into blastulae with a small central cavity. The mesoderm forms by delamination starting from the distal side towards the proximal end. In later embryos two polypides form on the posterior side that ultimately will be covered by a ciliated mantle in the larva. Embryos increase in size during development and form temporary cell contacts to the embryo sac. Mesodermal cells of the embryo sac show signs of transcellular transport indicating that embryos are nourished by transferring nutrients from the maternal coelom towards the brood cavity. This study clarifies several details such as mesoderm formation and the onset of bud development. Embryos are connected to their respective embryo sacs by a variety of temporary cytoplasmic processes formed by both tissues during embryogenesis, including a ‘placental’ ring zone. Although ultrastructural data of these cell contacts are not entirely conclusive about their function, we suggest that embryos absorb nutrients via the entire surface. The close opposition of embryos to the embryo sac implies placentation as matrotrophic mode in phylactolaemate bryozoans, with embryo sacs acting as placental analogues.

scholarly journals Unfolded protein response triggers differential apoptotic mechanisms in ovaries and early embryos exposed to maternal type 1 diabetes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aslı Okan ◽  
Necdet Demir ◽  
Berna Sozen
Keyword(s):  
Embryonic Development ◽  
Er Stress ◽  
Unfolded Protein Response ◽  
Molecular Mechanisms ◽  
Early Embryonic Development ◽  
Unfolded Protein ◽  
Caspase 12 ◽  
Early Embryos ◽  
Protein Response

AbstractDiabetes mellitus (DM) has profound effects on the female mammalian reproductive system, and early embryonic development, reducing female reproductive outcomes and inducing developmental programming in utero. However, the underlying cellular and molecular mechanisms remain poorly defined. Accumulating evidence implicates endoplasmic reticulum (ER)-stress with maternal DM associated pathophysiology. Yet the direct pathologies and causal events leading to ovarian dysfunction and altered early embryonic development have not been determined. Here, using an in vivo mouse model of Type 1 DM and in vitro hyperglycaemia-exposure, we demonstrate the activation of ER-stress within adult ovarian tissue and pre-implantation embryos. In diabetic ovaries, we show that the unfolded protein response (UPR) triggers an apoptotic cascade by the co-activation of Caspase 12 and Cleaved Caspase 3 transducers. Whereas DM-exposed early embryos display differential ER-associated responses; by activating Chop in within embryonic precursors and Caspase 12 within placental precursors. Our results offer new insights for understanding the pathological effects of DM on mammalian ovarian function and early embryo development, providing new evidence of its mechanistic link with ER-stress in mice.

scholarly journals Single cell RNA-seq reveals genes vital to in vitro fertilized embryos and parthenotes in pigs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhi-Qiang Du ◽  
Hao Liang ◽  
Xiao-Man Liu ◽  
Yun-Hua Liu ◽  
Chonglong Wang ◽  
...  
Keyword(s):  
Embryo Development ◽  
Gene Networks ◽  
Regulatory Networks ◽  
Rna Binding ◽  
Expression Patterns ◽  
Early Embryo ◽  
Specific Factor ◽  
Early Embryos ◽  
Genome Activation

AbstractSuccessful early embryo development requires the correct reprogramming and configuration of gene networks by the timely and faithful execution of zygotic genome activation (ZGA). However, the regulatory principle of molecular elements and circuits fundamental to embryo development remains largely obscure. Here, we profiled the transcriptomes of single zygotes and blastomeres, obtained from in vitro fertilized (IVF) or parthenogenetically activated (PA) porcine early embryos (1- to 8-cell), focusing on the gene expression dynamics and regulatory networks associated with maternal-to-zygote transition (MZT) (mainly maternal RNA clearance and ZGA). We found that minor and major ZGAs occur at 1-cell and 4-cell stages for both IVF and PA embryos, respectively. Maternal RNAs gradually decay from 1- to 8-cell embryos. Top abundantly expressed genes (CDV3, PCNA, CDR1, YWHAE, DNMT1, IGF2BP3, ARMC1, BTG4, UHRF2 and gametocyte-specific factor 1-like) in both IVF and PA early embryos identified are of vital roles for embryo development. Differentially expressed genes within IVF groups are different from that within PA groups, indicating bi-parental and maternal-only embryos have specific sets of mRNAs distinctly decayed and activated. Pathways enriched from DEGs showed that RNA associated pathways (RNA binding, processing, transport and degradation) could be important. Moreover, mitochondrial RNAs are found to be actively transcribed, showing dynamic expression patterns, and for DNA/H3K4 methylation and transcription factors as well. Taken together, our findings provide an important resource to investigate further the epigenetic and genome regulation of MZT events in early embryos of pigs.

Nutritional Status Impacts Epigenetic Regulation in Early Embryo Development: A Scoping Review

2021 ◽  
Author(s):  
Shuang Cai ◽  
Shuang Quan ◽  
Guangxin Yang ◽  
Meixia Chen ◽  
Qianhong Ye ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Embryo Development ◽  
Epigenetic Regulation ◽  
Scoping Review ◽  
Epigenetic Modification ◽  
Reproductive Technologies ◽  
Early Embryo ◽  
Epigenetic Modifications ◽  
Nutrition Status ◽  
Early Embryo Development

ABSTRACTWith the increasing maternal age and the use of assisted reproductive technology in various countries worldwide, the influence of epigenetic modification on embryonic development is increasingly notable and prominent. Epigenetic modification disorders caused by various nutritional imbalance would cause embryonic development abnormalities and even have an indelible impact on health in adulthood. In this scoping review, we summarize the main epigenetic modifications in mammals and the synergies among different epigenetic modifications, especially DNA methylation, histone acetylation, and histone methylation. We performed an in-depth analysis of the regulation of various epigenetic modifications on mammals from zygote formation to cleavage stage and blastocyst stage, and reviewed the modifications of key sites and their potential molecular mechanisms. In addition, we discuss the effects of nutrition (protein, lipids, and one-carbon metabolism) on epigenetic modification in embryos and emphasize the importance of various nutrients in embryonic development and epigenetics during pregnancy. Failures in epigenetic regulation have been implicated in mammalian and human early embryo loss and disease. With the use of reproductive technologies, it is becoming even more important to establish developmentally competent embryos. Therefore, it is essential to evaluate the extent to which embryos are sensitive to these epigenetic modifications and nutrition status. Understanding the epigenetic regulation of early embryo development will help us make better use of reproductive technologies and nutrition regulation to improve reproductive health in mammals.

An experimental study on neural crest migration in Barbus conchonius (Cyprinidae, Teleostei), with special reference to the origin of the enteroendocrine cells

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 309-323
Author(s):  
C. H. J. Lamers ◽  
J. W. H. M. Rombout ◽  
L. P. M. Timmermans
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Ganglion Cells ◽  
Neural Crest Cells ◽  
Enteroendocrine Cells ◽  
Pigment Cells ◽  
Transplantation Technique ◽  
Spinal Ganglion Cells ◽  
Neural Crest Origin ◽  
Neural Crest Migration

A neural crest transplantation technique is described for fish. As in other classes ofvertebrates, two pathways of neural crest migration can be distinguished: a lateroventral pathway between somites and ectoderm, and a medioventral pathway between somites and neural tube/notochord. In this paper evidence is presented for a neural crest origin of spinal ganglion cells and pigment cells, and indication for such an origin is obtained for sympathetic and enteric ganglion cells and for cells that are probably homologues to adrenomedullary and paraganglion cells in the future kidney area. The destiny of neural crest cells near the developing lateral-line sense organs is discussed. When grafted into the yolk, neural crest cells or neural tube cells appear to differentiate into ‘periblast cells’; this suggests a highly activating influence of the yolk. Many neural crest cells are found around the urinary ducts and, when grafted below the notochord, even within the urinary duct epithelium. These neural crest cells do not invade the gut epithelium, even when grafted adjacent to the developing gut. Consequently enteroendocrine cells in fish are not likely to have a trunkor rhombencephalic neural crest origin. Another possible origin of these cells will be proposed.

scholarly journals Dynamics of Structural Barriers and Innate Immune Components during Incubation of the Avian Egg: Critical Interplay between Autonomous Embryonic Development and Maternal Anticipation

2018 ◽  
Vol 11 (2) ◽  
pp. 111-124 ◽  
Author(s):  
Maxwell T. Hincke ◽  
Mylène Da Silva ◽  
Nicolas Guyot ◽  
Joël Gautron ◽  
Marc D. McKee ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Innate Immune ◽  
Vitelline Membrane ◽  
Structural Barriers ◽  
Embryonic Tissues ◽  
Egg Incubation ◽  
Evolutionary Success ◽  
Protective Structures ◽  
Amniotic Membranes ◽  
Autonomous Development

The integrated innate immune features of the calcareous egg and its contents are a critical underpinning of the remarkable evolutionary success of the Aves clade. Beginning at the time of laying, the initial protective structures of the egg, i.e., the biomineralized eggshell, egg-white antimicrobial peptides, and vitelline membrane, are rapidly and dramatically altered during embryonic development. The embryo-generated extra-embryonic tissues (chorioallantoic/amniotic membranes, yolk sac, and associated chambers) are all critical to counteract degradation of primary egg defenses during development. With a focus on the chick embryo (Gallus gallus domesticus), this review describes the progressive transformation of egg innate immunity by embryo-generated structures and mechanisms over the 21-day course of egg incubation, and also discusses the critical interplay between autonomous development and maternal anticipation.

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