Academic literature on the topic 'Embryonic developmenet'

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Journal articles on the topic "Embryonic developmenet"

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Güralp, H., K. Pocherniaieva, M. Blecha, T. Policar, M. Pšenička, and T. Saito. "Early embryonic development in pikeperch (Sander lucioperca) related to micromanipulation." Czech Journal of Animal Science 61, No. 6 (July 15, 2016): 273–80. http://dx.doi.org/10.17221/35/2015-cjas.

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Doetschman, Thomas C., Harald Eistetter, Margot Katz, Werner Schmidt, and Rolf Kemler. "The in vitro development of blastocyst-derived embryonic stem cell lines: formation of visceral yolk sac, blood islands and myocardium." Development 87, no. 1 (June 1, 1985): 27–45. http://dx.doi.org/10.1242/dev.87.1.27.

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The in vitro developmental potential of mouse blastocyst-derived embryonic stem cell lines has been investigated. From 3 to 8 days of suspension culture the cells form complex embryoid bodies with endoderm, basal lamina, mesoderm and ectoderm. Many are morphologically similar to embryos of the 6- to 8-day egg-cylinder stage. From 8 to 10 days of culture about half of the embryoid bodies expand into large cystic structures containing alphafoetoprotein and transferrin, thus being analagous to the visceral yolk sac of the postimplantation embryo. Approximately one third of the cystic embryoid bodies develop myocardium and when cultured in the presence of human cord serum, 30 % develop blood islands, thereby exhibiting a high level of organized development at a very high frequency. Furthermore, most embryonic stem cell lines observed exhibit similar characteristics. The in vitro developmental potential of embryonic stem cell lines and the consistency with which the cells express this potential are presented as aspects which open up new approaches to the investigation of embryogenesis.
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Derebail, Suchitra, Casthri Krishnamurthy, Ong Hong Boon, Ang Kailin, Nur Amilia Bte M. Isa, Nur Ayuni Bte Hassan Jaya, and Orr Hui Min. "REVIEW." Asia-Pacific Biotech News 18, no. 01 (January 2014): 47–51. http://dx.doi.org/10.1142/s0219030314000068.

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Faria, Claudia, Rita Borges, Fátima Gil, Vitor C. Almada, and Emanuel J. Gonçalves. "Embryonic and larval development of Lipophrys pholis (Pisces: Blenniidae)." Scientia Marina 66, no. 1 (March 30, 2002): 21–26. http://dx.doi.org/10.3989/scimar.2002.66n121.

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Ross, Sharon A., Peter J. McCaffery, Ursula C. Drager, and Luigi M. De Luca. "Retinoids in Embryonal Development." Physiological Reviews 80, no. 3 (July 1, 2000): 1021–54. http://dx.doi.org/10.1152/physrev.2000.80.3.1021.

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The key role of vitamin A in embryonal development is reviewed. Special emphasis is given to the physiological action of retinoids, as evident from the retinoid ligand knockout models. Retinoid metabolism in embryonic tissues and teratogenic consequences of retinoid administration at high doses are presented. Physiological and pharmacological actions of retinoids are outlined and explained on the basis of their interactions as ligands of the nuclear retinoid receptors. Immediate target genes and the retinoid response elements of their promoters are summarized. The fundamental role of homeobox genes in embryonal development and the actions of retinoids on their expression are discussed. The similarity of the effects of retinoid ligand knockouts to effects of compound retinoid receptor knockouts on embryogenesis is presented. Although much remains to be clarified, the emerging landscape offers exciting views for future research.
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Murray, Patricia, and David Edgar. "Regulation of Programmed Cell Death by Basement Membranes in Embryonic Development." Journal of Cell Biology 150, no. 5 (September 4, 2000): 1215–21. http://dx.doi.org/10.1083/jcb.150.5.1215.

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The formation of the proamniotic cavity in the mammalian embryo is the earliest of many instances throughout development in which programmed cell death and the formation of epithelia play fundamental roles (Coucouvanis, E., and G.R. Martin. 1995. Cell. 83:279–287). To determine the role of the basement membrane (BM) in cavitation, we use embryoid bodies derived from mouse embryonic stem cells in which the LAMC1 genes have been inactivated to prevent BM deposition (Smyth, N., H.S. Vatansever, P. Murray, M. Meyer, C. Frie, M. Paulsson, and D. Edgar. 1999. J. Cell Biol. 144:151–610). We demonstrate here that LAMC1−/− embryoid bodies are unable to cavitate, and do not form an epiblast epithelium in the absence of a BM, although both embryonic ectodermal cells and extraembryonic endodermal cells do differentiate, as evidenced by the expression of cell-specific markers. Acceleration or rescue of BM deposition by exogenous laminin in wild-type or LAMC1−/− embryoid bodies, respectively, results in cavitation that is temporally and spatially associated with restoration of epiblast epithelial development. We conclude that the BM not only directly regulates development of epiblast epithelial cells, but also indirectly regulates the programmed cell death necessary for cavity formation.
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Przyborski, S. A., V. B. Christie, M. W. Hayman, R. Stewart, and G. M. Horrocks. "Human Embryonal Carcinoma Stem Cells: Models of Embryonic Development in Humans." Stem Cells and Development 13, no. 4 (August 2004): 400–408. http://dx.doi.org/10.1089/scd.2004.13.400.

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Jakobsson, Lars, Johan Kreuger, and Lena Claesson-Welsh. "Building blood vessels—stem cell models in vascular biology." Journal of Cell Biology 177, no. 5 (May 29, 2007): 751–55. http://dx.doi.org/10.1083/jcb.200701146.

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Spheroids of differentiating embryonic stem cells, denoted embryoid bodies, constitute a high-quality model for vascular development, particularly well suited for loss-of-function analysis of genes required for early embryogenesis. This review examines vasculogenesis and angiogenesis in murine embryoid bodies and discusses the promise of stem cell–based models for the study of human vascular development.
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Yuan, Jianbo, Yuehui Chao, and Liebao Han. "Uncovering a Phenomenon of Active Hormone Transcriptional Regulation during Early Somatic Embryogenesis in Medicago sativa." International Journal of Molecular Sciences 23, no. 15 (August 3, 2022): 8633. http://dx.doi.org/10.3390/ijms23158633.

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Somatic embryogenesis (SE) is a developmental process in which somatic cells undergo dedifferentiation to become plant stem cells, and redifferentiation to become a whole embryo. SE is a prerequisite for molecular breeding and is an excellent platform to study cell development in the majority of plant species. However, the molecular mechanism involved in M. sativa somatic embryonic induction, embryonic and maturation is unclear. This study was designed to examine the differentially expressed genes (DEGs) and miRNA roles during somatic embryonic induction, embryonic and maturation. The cut cotyledon (ICE), non-embryogenic callus (NEC), embryogenic callus (EC) and cotyledon embryo (CE) were selected for transcriptome and small RNA sequencing. The results showed that 17,251 DEGs, and 177 known and 110 novel miRNAs families were involved in embryonic induction (ICE to NEC), embryonic (NEC to EC), and maturation (EC to CE). Expression patterns and functional classification analysis showed several novel genes and miRNAs involved in SE. Moreover, embryonic induction is an active process of molecular regulation, and hormonal signal transduction related to pathways involved in the whole SE. Finally, a miRNA–target interaction network was proposed during M. sativa SE. This study provides novel perspectives to comprehend the molecular mechanisms in M. sativa SE.
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Wheeler, MB. "Development and validation of swine embryonic stem cells: a review." Reproduction, Fertility and Development 6, no. 5 (1994): 563. http://dx.doi.org/10.1071/rd9940563.

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The establishment of embryonic cell lines from swine should be useful for studies of cell differentiation, developmental gene regulation and the production of transgenics. This paper summarizes the establishment of porcine (Sus scrofa) embryonic stem (ES) cell lines from preimplantation blastocysts and their ability to develop into normal chimaeras. ES cells can spontaneously differentiate into cystic embryoid bodies with ectodermal, endodermal, and mesodermal cell types. Further, culture of ES cells to confluence or induction of differentiation with retinoic acid or dimethylsulfoxide results in morphological differentiation into fibroblasts, adipocytes, and epithelial, neuronal, and muscle cells. These ES cells have a normal diploid complement of 38 chromosomes. Scanning electron microscopy of the ES cells reveals a rounded or polygonal, epithelial-like cell with numerous microvilli. The differentiation of these embryonic cell lines into several cell types indicates a pluripotent cell. Furthermore, chimaeric swine have been successfully produced using such ES cells.
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Dissertations / Theses on the topic "Embryonic developmenet"

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Salanga, Matthew Charles. "EMBRYONIC VASCULAR DEVELOPMENT." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/203435.

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The formation of the embryonic vasculature is essential for life. The components driving this process are well conserved across vertebrate species. At the core of vascular development is the specification of endothelial precursor cells from nascent mesoderm. Transcription factors of the ETS family are important regulators of endothelial specification. In this document we characterize the role of the ETS transcription factors, ETV2, during embryonic vascular development.Expression analysis shows that Etv2 is highly expressed in hematopoietic and endothelial precursor cells in the Xenopus embryo. In gain-of-function experiments, ETV2 is sufficient to activate ectopic expression of vascular endothelial markers. In addition, ETV2 activated expression of hematopoietic genes representing the myeloid but not the erythroid lineage. Loss-of-function studies indicate that ETV2 is required for expression of all endothelial markers examined. However, knockdown of ETV2 has no detectable effects on expression of either myeloid or erythroid markers. This contrasts with studies in mouse and zebrafish where ETV2 is required for development of the myeloid lineage. Our studies confirm an essential role for ETV2 in endothelial development, but also reveal important differences in hematopoietic development between organisms.Although ETV2 is a pivotal molecule in development it remains unidentified in the chicken genome. We hypothesize that chicken Etv2 is expressed in the early Gallus embryo, and is necessary for endothelial specification consistent with its role in other species. To test this hypothesis we attempted to amplify Etv2 transcripts from Gallus embryos using degenerate PCR. Disappointingly this strategy did not reveal a putative Etv2 candidate. However, some important findings were uncovered, including the cloning of a previously uncharacterized Gallus ETS protein, SPDEF. Additionally the identification of an annotation error mis-identifying Ets gene "Erf" as "Etv3" (also an Ets gene) provided details on gene arrangement previously unknown. The workflow described could be used in future studies for the identification of other members of gene families that exhibit gaps, keeping in mind the goal of the study and the limitations of each technology.
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Ladd, Sabine Margaret. "Effects of Diethylstilbestrol on Murine Early Embryonic Stem Cell Differentiation Using an Embryoid Body Culture System." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/31999.

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Objectives: The effects of estrogens on immune system formation and function are well documented. Diethylstilbestrol (DES), a synthetic estrogen, has been linked to neoplasia and immune cell dysfunction in humans and animals exposed in-utero. In-vitro effects of DES exposure of murine embryonic stem (ES) cells on the early embryonic immune system development and the expression of cellular surface markers associated with common hemangioblastic and hematopoietic precursors of the endothelial, lymphoid & myeloid lineages were investigated. Hypothesis: Early ES cell expression of CD45 a marker common to lymphoid lineage hematopoietic stem cells and differentiation of lymphoid lineage precursors are affected by in-vitro exposure to DES. Methods: Murine ES cells were cultured using a variety of techniques: an OP9 co-culture system, and formation of embryoid bodies (EBs) in a liquid medium and hanging drop system. The OP9 co-culture system did not appear to give rise to well differentiated lymphoid lineage cells during 12 days of differentiation. The hanging drop EB culture system, previously shown to promote differentiation of endothelial and lymphoid precursor cells, was chosen for further studies of ES cell differentiation. ES cells were harvested at five time points: undifferentiated (day 0), and differentiated (days 3, 8, 12 and 16). Differentiating ES cells were treated with DES beginning on day 3. The synthetic estrogen, DES, was chosen as a treatment because of its similar potency to 17β estradiol and documented association with neoplasia in women exposed in-utero. Surface marker expression, measured by real-time RT-PCR amplification, was recorded using fluorogenic TaqMan(R) probes designed specifically for the surface proteins of interest: oct4, c-Kit, Flk1, ERα, ERβ, CD45, Flt1, & VE-cadherin. Analysis & Results: Changes in surface marker gene expression between day 0 and day 16 of differentiation were analyzed using the RT-PCR threshold counts (CT) and the comparative threshhold cycle method. The expression of each target mRNA was normalized internally to a housekeeping gene (18s rRNA) and calculated relative to day 0. ANOVA (Type 3 fixed-effects analysis, SAS) was performed using the unexponentiated ΠΠCT values. The effects of DES, time, and the interaction between DES and time were evaluated for days 8, 12 and 16. Additionally, the effects of DES on the expression of each marker were evaluated for day 16. Expression of estrogen receptor receptor α & β (ERα & β) in the EBs was established, and did not appear to be affected at any time by treatment with DES. ERα was expressed in significant levels on day 16, while ERβ was expressed in low levels throughout the period of differentiation. The expression of the cell surface marker, c-Kit was significantly (P<0.0001) altered by the presence of DES between the three time points sampled. The expression of the VEGF receptor, Flt1, and the adhesion molecule, VE-cadherin, markers of endothelial cells, were also significantly (P<0.026) altered by treatment with DES on day 16 of differentiation. Treatment with DES appeared to have no effect on the expression of CD45, a marker common to lymphoid precursor cells. Conclusions: These results indicate the presence of estrogen receptors in differentiating ES cells as early as day three in-vitro (ERβ) until day 16 (ERα). DES alters expression of common hemangioblastic and hematopoietic precursor, as well as endothelial lineage markers, but has no effect on expression of the marker of lymphoid lineage development before day 16. These effects coincided with the expression of ERα. The enduring effects of DES exposure in-utero may not be manifest in this ES model, or may occur at later stages of differentiation or in selected subpopulations of CD45+ cells.
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Matsuura, Rie, Hiroshi Kogo, Takunori Ogaeri, Takashi Miwa, Masaki Kuwahara, Yoshiakira Kanai, Takumi Nakagawa, et al. "Crucial transcription factors in endoderm and embryonic gut development are expressed in gut-like structures from mouse ES cells." Alpha Med Press, 2006. http://hdl.handle.net/2237/7444.

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Harrison, Sarah Ellys. "Utilising embryonic and extra-embryonic stem cells to model early mammalian embryogenesis in vitro." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/275424.

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Successful mammalian development to term requires that embryonic and extra-embryonic tissues communicate and grow in coordination, to form the body. After implanting into the uterus, the mouse embryo is comprised of three cell lineages: first, the embryonic epiblast (EPI) that forms the embryo proper, second, the extra-embryonic ectoderm (ExE) which contributes to the foetal portion of the placenta, and third, the visceral endoderm (VE) that contributes to the yolk sac. These three tissues form a characteristic ‘egg-cylinder’ structure, which allows signals to be exchanged between them and sets the stage for body axis establishment and subsequent tissue patterning. The mechanisms underlying this process are difficult to study in vivo because a different genetically manipulated mouse line must be generated to investigate each factor involved. This difficulty has prompted efforts to model mammalian embryogenesis in vitro, using cell lines, which are more amenable to genetic manipulation. The pluripotent state of the EPI can be captured in vitro as mammalian embryonic stem cells (ESCs). Although mouse ESCs have been shown to contribute to all adult tissues in chimeric embryos, they cannot undertake embryogenesis when allowed to differentiate in culture. Previous studies have shown that ESCs formed into three-dimensional (3D) aggregates, called embryoid bodies, can become patterned and express genes associated with early tissue differentiation. However, embryoid bodies cannot recapitulate embryonic architecture and therefore may not accurately reflect what happens in the embryo. In this study, a new technique was developed to model early mouse development which is more faithful to the embryo. ESCs were co-cultured with stem cells derived from the ExE, termed trophoblast stem cells (TSCs), embedded within extracellular matrix (ECM). These culture conditions lead to the self-assembly of embryo-like structures with similar architecture to the mouse egg cylinder. They were comprised of an embryonic compartment derived from ESCs abutting an extra-embryonic compartment derived from TSCs, and hence were named ‘ETS-embryos’. These structures developed a continuous cavity at their centre, which formed via a similar sequence of events to those that lead to pro-amniotic cavity formation in the mouse embryo, and required active Nodal/Activin signalling. After cavitation, ‘ETS-embryos’ developed regionalised mesodermal tissue and primordial germ cell-like cells originating at the boundary between embryonic and extra-embryonic compartments. Inhibitor studies revealed that this occurred in response to endogenous Wnt and BMP signalling, pathways which also govern these tissue specification events in the early mouse embryo. To demonstrate that ‘ETS-embryos’ were comparable to mouse embryos at the global transcriptional level, RNA-sequencing was then performed on different tissue regions of ‘ETS-embryos’ and the resulting transcriptomes were compared to datasets from mouse embryos. These data showed that ‘ETS-embryos’ were highly similar to mouse embryos at post-implantation stages in their overall gene expression patterns. Taken together, these results indicate that ‘ETS-embryos’ are an accurate in vitro model of mammalian embryogenesis, which can be used to complement studies undertaken in vivo to investigate early development.
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Losa, Llabata Marta. "Gene regulation in embryonic development." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/gene-regulation-in-embryonic-development(8a9efb79-1ca9-409e-89b9-9d66213e593f).html.

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Branchial arches (BAs) are a series of transient structures that develop on the ventro-lateral surface of the head in vertebrate embryos. BAs initially appear as a series of similar segments; as development proceeds each BA will contribute to different structures. Here, it was investigated the transcriptional mechanisms that instruct the different fates of the BAs in development. Initially, each BA contains a blood vessel, known as aortic arch (AA) artery, that connects the dorsal aorta with the heart. Remodelling of the AAs is crucial to form the adult heart circulation. This process leads to regression of the anterior AAs, running though the first and second BAs (BA1 and BA2), and persistence of the AAs contained in more posterior BAs (PBA). To identify the mechanisms that control remodelling of the AAs, we compared the transcriptomes and epigenomic landscapes of different BAs. Using RNA-seq and H3K27Ac ChIP-seq, we uncovered the activation of a vascular smooth muscle cell (VSMC) differentiation transcriptional program exclusively in the PBAs (and not in BA1/BA2). In support of this finding, we show that VSMC differentiation occurs specifically in the PBAs, but not BA1-2 in mouse embryonic development. Despite the absence of VSMC differentiation in developing BA1-2, cells harvested from these tissues reveal a spontaneous tendency to differentiate towards VSMC fate when grown in vitro, and activate several VSMC-specific genes (Myocd, Acta2, Tagln, Jag1). Together, our results suggest that forming VSMCs is a key process for the persistence of AAs. We also showed that cells derived from all BAs have the potential to differentiate to VSMCs in vitro. However, only cells in the PBAs differentiate to VSMCs in vivo, resulting in the maintenance of posterior AAs. In this study, we also uncovered a novel transcriptional principle that specifies the fate of BA2. Using ChIP-seq, we found that binding of Meis transcription factors establish a ground pattern in the BAs. Hoxa2, which specifies BA2 identity, selects a subset of Meis-bound sites. Meis binding is strongly increased at these sites, which coincide with active enhancers, linked to genes highly expressed in the BA2 and regulated by Hoxa2. Thus, Hoxa2 modifies a ground state binding of Meis to instruct segment-specific transcriptional programs.
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Vaahtokari, Anne. "Molecular mechanisms in embryonic tooth development." Helsinki : Dept. of Dentistry, Division of Pedodontics and Orthodontics, Institute of Biotechnology and Dept. of Biosciences, Division of Biochemistry, University of Helsinki, 1996. http://catalog.hathitrust.org/api/volumes/oclc/35253532.html.

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Shivji, Nadia. "GnRH neuron migration during embryonic development." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611556.

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Jörg, David Josef. "Genetic Oscillations and Vertebrate Embryonic Development." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-159034.

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Recurrent processes are a general feature of living systems, from the cell cycle to circadian day-night rhythms to hibernation and flowering cycles. During development and life, numerous recurrent processes are controlled by genetic oscillators, a specific class of genetic regulatory networks that generates oscillations in the level of gene products. A vital mechanism controlled by genetic oscillators is the rhythmic and sequential segmentation of the elongating body axis of vertebrate embryos. During this process, a large collection of coupled genetic oscillators gives rise to spatio-temporal wave patterns of oscillating gene expression at tissue level, forming a dynamic prepattern for the precursors of the vertebrae. While such systems of genetic oscillators have been studied extensively over the past years, many fundamental questions about their collective behavior remain unanswered. In this thesis, we study the behavior and the properties of genetic oscillators from the single oscillator scale to the complex pattern forming system involved in vertebrate segmentation. Genetic oscillators are subject to fluctuations because of the stochastic nature of gene expression. To study the effects of noisy biochemical coupling on genetic oscillators, we propose a theory in which both the internal dynamics of the oscillators as well as the coupling process are inherently stochastic. We find that stochastic coupling of oscillators profoundly affects their precision and synchronization properties, key features for their viability as biological pacemakers. Moreover, stochasticity introduces phenomena not known from deterministic systems, such as stochastic switching between different modes of synchrony. During vertebrate segmentation, genetic oscillators play a key role in establishing a segmental prepattern on tissue scale. We study the spatio-temporal patterns of oscillating gene expression using a continuum theory of coupled phase oscillators. We investigate the effects of different biologically relevant factors such as delayed coupling due to complex signaling processes, local tissue growth, and tissue shortening on pattern formation and segmentation. We find that the decreasing tissue length induces a Doppler effect that contributes to the rate of segment formation in a hitherto unanticipated way. Comparison of our theoretical findings with experimental data reveals the occurrence of such a Doppler effect in vivo. To this end, we develop quantification methods for the spatio-temporal patterns of gene expression in developing zebrafish embryos. On a cellular level, tissues have a discrete structure. To study the interplay of cellular processes like cell division and random cell movement with pattern formation, we go beyond the coarse-grained continuum theories and develop a three-dimensional cell-based model of vertebrate segmentation, in which the dynamics of the segmenting tissue emerges from the collective behavior of individual cells. We show that this model is able to describe tissue formation and segmentation in a self-organized way. It provides the first step of theoretically describing pattern formation and tissue dynamics during vertebrate segmentation in a unified framework involving a three-dimensional tissue with cells as distinct mechanical entities. Finally, we study the synchronization dynamics of generic oscillator systems whose coupling is subject to phase shifts and time delays. Such phase shifts and time delays are induced by complex signaling processes as found, e.g., between genetic oscillators. We show how phase shifts and coupling delays can alter the synchronization dynamics while leaving the collective frequency of the synchronized oscillators invariant. We find that in globally coupled systems, fastest synchronization occurs for non-vanishing coupling delays while in spatially extended systems, fastest synchronization can occur on length scales larger than the coupling range, giving rise to novel synchronization scenarios. Beyond their potential relevance for biological systems, these results have implications for general oscillator systems, e.g., in physics and engineering. In summary, we use discrete and continuous theories of genetic oscillators to study their dynamic behavior, comparing our theoretical results to experimental data where available. We cover a wide range of different topics, contributing to the general understanding of genetic oscillators and synchronization and revealing a hitherto unknown mechanism regulating the timing of embryonic pattern formation.
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Abdullah, A. R. "Mathematical modelling of embryonic tissue development." Thesis, University of Liverpool, 2018. http://livrepository.liverpool.ac.uk/3028456/.

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Cheung, Kwok Kuen. "Purinergic signaling during rat embryonic development." Thesis, University College London (University of London), 2004. http://discovery.ucl.ac.uk/1446895/.

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Adenosine 5'-triphosphate (ATP) has been shown to be an important extracellular signaling molecule that mediates various physiological activities via the P2 (P2X and P2Y) receptors. However, information on the expression patterns of the P2 receptors during mammalian embryogenesis is limited. We therefore examined the expression patterns of different P2 receptor subtypes in rat embryos. In the hindbrain neural tube, the P2X3 receptor was transiently expressed at embryonic day E11 in the cranial motor neurons and the outgrowing axons. ATP significantly inhibited neurite outgrowth from neural tube explants. P2X3 receptors were also prominently expressed in sensory ganglia at this early stage and were coexpressed with P2X2 receptors in El6.5 embryos. Other P2X receptor subtypes were observed in different brain regions such as subventricular zones, the site of postnatal neurogenesis. In addition, the P2Y receptor expression was detected in the somites and subsequently in the developing skeletal muscle but was downregulated as development proceeded. While the P2Y1 receptor was no longer expressed in the adult skeletal muscle, the expression of P2Y2 receptor was present, although restricted in the satellite cells and the P2Y4 receptor showed reduced expression in adult skeletal muscle. Likewise, the expression of the P2Y receptors was initially expressed throughout the myocardium (El2) but was gradually restricted to the trabeculated myocardium (El4-18). Studies on Ca2+ influx showed that particular P2 receptor subtypes of P2X2, P2X4, P2Y1, P2Y2, P2Y4 and P2Y6 receptors responded to nucleotides in E14 cardiomyocytes. P2X7 receptor expression was detected in developing pancreatic islet cells and later coexpressed with glucagon in ?-cells. In addition, transient expression of the P2X7 receptor in insulin-expressing cells was observed in the embryonic, but not in adult, islet cells. Together, the results indicated that widespread and dynamic expression of P2 receptors was found in the three-germ layer-derived embryonic tissues, particularly in some transient embryonic structures during development, which suggested they may be important in embryonic organogenesis.
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Books on the topic "Embryonic developmenet"

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Spemann, Hans. Embryonic development and induction. New York: Garland Pub., 1988.

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George, Lefevre, ed. Introduction to embryonic development. 3rd ed. Boston: Allyn and Bacon, 1989.

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S, Baranov V., ed. Cytogenetics of mammalian embryonic development. Oxford: Clarendon Press, 1987.

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Ormestad, Mattias. FoxF genes in embryonic development. Göteborg: Department of Cell and Molecular Biology, Göteborg University, 2006.

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Hennig, Wolfgang, ed. Early Embryonic Development of Animals. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-540-47191-2.

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Campos-Ortega, José A., and Volker Hartenstein. The Embryonic Development of Drosophila melanogaster. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-662-02454-6.

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Campos-Ortega, José A., and Volker Hartenstein. The Embryonic Development of Drosophila melanogaster. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-662-22489-2.

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Kavlock, Robert J., and George P. Daston, eds. Drug Toxicity in Embryonic Development I. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60445-4.

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Kavlock, Robert J., and George P. Daston, eds. Drug Toxicity in Embryonic Development II. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60447-8.

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Campos-Ortega, José A. The embryonic development of Drosophila melanogaster. 2nd ed. Berlin: Springer, 1997.

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Book chapters on the topic "Embryonic developmenet"

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Gillott, Cedric. "Embryonic Development." In Entomology, 569–94. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-017-4380-8_20.

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Dancygier, Henryk. "Embryonic Development." In Clinical Hepatology, 7–10. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-540-93842-2_1.

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Weis, Judith S. "Embryonic Development." In Physiological, Developmental and Behavioral Effects of Marine Pollution, 169–214. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-6949-6_6.

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Punzo, Fred. "Embryonic Development." In Adaptations of Desert Organisms, 15–45. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-662-04090-4_2.

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Dettlaff, Tatiana A., Anna S. Ginsburg, and Olga I. Schmalhausen. "Embryonic Development." In Sturgeon Fishes, 49–154. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-77057-9_3.

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Baets, Kenneth De, Neil H. Landman, and Kazushige Tanabe. "Ammonoid Embryonic Development." In Topics in Geobiology, 113–205. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-9630-9_5.

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Landman, Neil H., Kazushige Tanabe, and Yasunari Shigeta. "Ammonoid Embryonic Development." In Topics in Geobiology, 343–405. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4757-9153-2_11.

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Campos-Ortega, José A., and Volker Hartenstein. "Mesoderm Development." In The Embryonic Development of Drosophila melanogaster, 103–8. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-662-22489-2_3.

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Hall, Brian K. "Homology and Embryonic Development." In Evolutionary Biology, 1–37. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4615-1847-1_1.

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Alvarez, Laura Macias, Jesus Revuelta-Cervantes, and Isabel Dominguez. "CK2 in Embryonic Development." In Protein Kinase CK2, 129–68. Oxford, UK: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118482490.ch4.

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Conference papers on the topic "Embryonic developmenet"

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Carraro, G., G. Turcatel, A. El-Hashash, and D. Warburton. "miR-17 Regulate Embryonic Lung Development." In American Thoracic Society 2009 International Conference, May 15-20, 2009 • San Diego, California. American Thoracic Society, 2009. http://dx.doi.org/10.1164/ajrccm-conference.2009.179.1_meetingabstracts.a3276.

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Larina, Irina V. "Live biophotonic analysis of embryonic development." In Dynamics and Fluctuations in Biomedical Photonics XIX, edited by Valery V. Tuchin, Martin J. Leahy, and Ruikang K. Wang. SPIE, 2022. http://dx.doi.org/10.1117/12.2631528.

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Wang, Yajuan, Onur Dur, Michael J. Patrick, Joseph P. Tinney, Kimimasa Tobita, Kerem Pekkan, and Bradley B. Keller. "Hemodynamic Investigation of Normal Developing Aortic Arch in the Chick Embryo." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-193264.

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Governed by genetic and epigenetic feedback [1], during embryonic cardiac development, the anatomy of aortic arches demonstrates drastic three dimensional (3D) changes that interact with the function of cardiovascular system. Six major pairs of aortic arches appear at different embryonic periods and eventually form the two brachiocephalic arteries (left and right third), an aortic arch (left fourth) and pulmonary arteries and ductus arteriosus (left and right sixth) [2–4], Fig 1. Flow-driven hemodynamic loading plays a major role in this dynamic process. Morphological studies on the embryonic aortic arches began over 100 years ago while the recent remarkable developments include understanding genetic determinants such as the effects of neural crest cells [5,6]. However the relationship between hemodynamic factors and the dynamic 3D geometry changes is still limited requiring an interdisciplinary research effort [7,8].
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Al-Saaidah, Bayan, Waleed Al-Nuaimy, Majid Al-Taee, Ali Al-Ataby, Iain Young, and Qussay Al-Jubouri. "Analysis of Embryonic Malformations in Zebrafish Larvae." In 2016 9th International Conference on Developments in eSystems Engineering (DeSE). IEEE, 2016. http://dx.doi.org/10.1109/dese.2016.7.

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Liu, Aiping, Kent Thornburg, Ruikang Wang, and Sandra Rugonyi. "Changes in Biomechanical Environment of Cardiac Cells in Chick Embryos After Cardiac Outflow Tract Banding." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53732.

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Embryonic cardiac cells are constantly exposed to biomechanical environments including cyclic stretch and wall shear stress (WSS), which regulate behaviors of cardiac cells, critical to heart development and function [1]. Disturbances in biomechanical environment may contribute to the heart defects that affect 1% of newborns each year in US. However, changes in the biomechanical signals that affect heart development remain undescribed, partly due to a lack of methodology to quantify the biomechanical environment in the embryonic heart.
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Li, Changlei, Xiji Shu, Xiaoqing Chen, Yuwei Liu, Huiling Yi, and Baomiao Ma. "Effect of Methamphetamine on Embryonic Development in Rats." In 2017 7th International Conference on Applied Science, Engineering and Technology (ICASET 2017). Paris, France: Atlantis Press, 2017. http://dx.doi.org/10.2991/icaset-17.2017.4.

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"Hydroxymethylation changes during early embryonic development in zebrafish." In Bioinformatics of Genome Regulation and Structure/ Systems Biology. institute of cytology and genetics siberian branch of the russian academy of science, Novosibirsk State University, 2020. http://dx.doi.org/10.18699/bgrs/sb-2020-044.

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Larina, Irina V. "In vivo biophotonic analysis of preimplantation embryonic development." In Biomedical Spectroscopy, Microscopy, and Imaging II, edited by Jürgen Popp and Csilla Gergely. SPIE, 2022. http://dx.doi.org/10.1117/12.2626872.

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Varner, Victor D., Dmitry A. Voronov, and Larry A. Taber. "Mechanics of Embryonic Head Fold Morphogenesis." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-193032.

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Head fold morphogenesis constitutes the first discernible epithelial folding event in the embryonic development of the chick. It arises at Hamburger and Hamilton (HH) stage 6 (approximately 24 hours into a 21-day incubation period) and establishes the anterior extent of the embryo [1]. At this stage, the embryonic blastoderm is composed of three germ layers (endoderm, mesoderm, and ectoderm), which are organized into a flat layered sheet that overlies the fibrous vitelline membrane (VM). Within this blastodermal sheet, a crescent-shaped head fold develops just anterior to the elongating notochord, spanning across the embryonic midline at the rostral end of neural plate. At the crest of this fold, the bilateral precardiac plates fuse in a cranial to caudal direction and give rise to the primitive heart tube and foregut [2, 3]. An understanding of head fold morphogenesis may thus offer insight into how embryonic tissues are arranged to make ready for proper cardiac formation.
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Troyanova-Wood, Maria, Zhaokai Meng, Hannah Silverberg, and Vladislav V. Yakovlev. "Brillouin microspectroscopy assessment of tissue differentiation during embryonic development." In SPIE BiOS, edited by Melissa C. Skala and Paul J. Campagnola. SPIE, 2017. http://dx.doi.org/10.1117/12.2253377.

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Reports on the topic "Embryonic developmenet"

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Harada, John J. Final Report for Regulation of Embryonic Development in Higher Plants. Office of Scientific and Technical Information (OSTI), October 2013. http://dx.doi.org/10.2172/1097049.

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Gershon, Eran, and Alan Ealy. Fibroblast growth factor signaling requirements for embryonic and placental development in ruminants. United States Department of Agriculture, January 2016. http://dx.doi.org/10.32747/2016.7600044.bard.

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Wright, Elane C., Cai-Xia Yang, Christopher K. Tuggle, and Jason W. Ross. Heat Stress during Pig Oocyte In Vitro Maturation Impacts Embryonic Development and Gene Expression. Ames (Iowa): Iowa State University, January 2012. http://dx.doi.org/10.31274/ans_air-180814-1373.

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Browdy, Craig, and Esther Lubzens. Cryopreservation of Penaeid Shrimp Embryos: Development of a Germplasm Cryo-Bank for Preservation of High Health and Genetically Improved Stocks. United States Department of Agriculture, August 2002. http://dx.doi.org/10.32747/2002.7695849.bard.

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The objectives of the project were to develop a successful protocol for cryopreservation of penaeid germ plasm in order to preserve a pathogen-free broodstock nucleus for commercial exploitation of marine shrimp in aquaculture. The critical parameters to be characterized in the project were: 1. Determination of chill sensitivity and chill tolerant embryonic stages, including a full description and time course study of embryonic developmental stages. 2. Development of protocols for loading and removal of cryoprotectant agents (CPAs) from embryos; determination of optimal concentrations and duration of loading. 3. Characterization of the toxicity of the selected CP As and 4. Establishing optimal cooling and thawing procedures. Studies were performed on two penaeid species: Litopenaeus vannamei (in the USA) and P. semisulcatus (in Israel). The effect of incubation temperature on embryonic development rate and hatching success was studied in L. vannamei, showing that spawns maybe maintained at temperatures ranging from 24°C to 30°C, without compromising hatchability. Embryonic development extends from 12 hr to 19 hr at 30°C and 24°C, respectively. Studies showed that advanced embryonic developmental stages were chill tolerant in the two studied species, but P. semisulcatus could better endure lower temperatures than L. vannamei. A large number of experiments were performed to determine the optimal CP As, their concentration and duration of loading. Permeating (e.g. glycerol, methanol, DMSO, 1,2- propanediol, ethylene glycol, glucose) and non-permeating CPAs (sucrose, PVP, polyethylene glycol) were tested and several combinations of permeating and non-permeating CP As, on fertilized eggs (embryos), nauplii and protozoeae. In general, nauplii tolerated higher CPA concentrations than eggs and nauplii were also more permeable to radiolabeled methanol. Chlorine treatment intended to remove the chitinous envelop from eggs, did not increase dramatically the permeation of radiolabled methanol into eggs. Cooling eggs, nauplii or protozoeae to cryogenic temperatures, by either vitrification or slow cooling protocols, did not result in full survival of thawed samples, despite exhaustive attempts testing various protocols and CP As. Results seemed more encouraging in freezing of nauplii in comparison to eggs or protozoeae. Successful preliminary results in cryopreservation of spermatozoa of P. vannamei, will facilitate preservation of genetic specific to some extent.
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Halevy, Orna, Zipora Yablonka-Reuveni, and Israel Rozenboim. Enhancement of meat production by monochromatic light stimuli during embryogenesis: effect on muscle development and post-hatch growth. United States Department of Agriculture, June 2004. http://dx.doi.org/10.32747/2004.7586471.bard.

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The original objectives were: A. To determine the critical embryonic age for monochromatic green light stimulation. B. To follow the ontogeny of embryos exposed to monochromatic green light vs. darkness. C. To investigate the effects of monochromatic green light illumination on myoblast and fiber development in the embryo. D. To investigate the stimulatory effect of light combinations during embryo and post-hatch periods on growth and meat production. E. To evaluate the direct effect of monochromatic green light on cultured embryonic and adult myoblasts. The overall purpose of this study was to investigate the effect of monochromatic light stimuli during incubation period of broilers on muscle development and satellite cell myogenesis. Based on previous studies (Halevy et al., 1998; Rozenboim et al., 1999) that demonstrated the positive effects of green-light illumination on body and muscle growth, we hypothesized that monochromatic light illumination accelerates embryo and muscle development and subsequently enhances muscle growth and meat production. Thus, further decreases management costs. Under the cooperation of the laboratories at the Hebrew University of Jerusalem and University of Washington we have conducted the following: 1. We have established the critical stage for exposure to green monochromatic light which has the maximal effect on body and muscle growth (Objective A). We report that embryonic day 5 is optimal for starting illumination. The optimal regime of lighting that will eliminate possible heat effects was evaluated by monitoring egg core temperature at various illumination periods. We found that intermitted lighting (15 min. on; 15 min. off) is optimal to avoid heat effects. 2. We have evaluated in detail gross changes in embryo development profile associated to green light stimuli vs. darkness. In addition, we have investigated the stimulatory effect of light combinations during embryo and post-hatch periods on body and muscle growth (Objective B,D). 3. We have studied the expression profile of muscle regulatory proteins during chicken muscle cell differentiation in cultures using newly developed antibodies. This study paved the way for analyzing the expression of these proteins in our photo stimulation experiments (Objective C). 4. We have studied the pattern ofPax7 expression during myogenesis in the posthatch chicken. Experimental chick pectoralis muscles as well adult myoblast cultures were used in this study and the results led us to propose a novel model for satellite cell differentiation and renewal. 5. The effects of monochromatic green light illumination during embryogenesis have been studied. These studies focused on fetal myoblast and satellite cell proliferation and differentiation at pre- and posthatch periods and on the effects on the expression of muscle regulatory proteins which are involved in these processes. In addition, we have analyzed the effect of photo stimulation in the embryo on myofiber development at early posthatch (Objective C). 6. In follow the reviewers' comments we have not conducted Objective E. The information gathered from these studies is of utmost importance both, for understanding the molecular basis of muscle development in the posthatch chicks and for applied approach for future broiler management. Therefore, the information could be beneficial to agriculture in the short term on the one hand and to future studies on chick muscle development in the embryo and posthatch on the other hand.
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Yahav, Shlomo, John Brake, and Orna Halevy. Pre-natal Epigenetic Adaptation to Improve Thermotolerance Acquisition and Performance of Fast-growing Meat-type Chickens. United States Department of Agriculture, September 2009. http://dx.doi.org/10.32747/2009.7592120.bard.

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: The necessity to improve broiler thermotolerance and performance led to the following hypothesis: (a) thethermoregulatory-response threshold for heat production can be altered by thermal manipulation (TM) during incubation so as to improve the acquisition of thermotolerance in the post-hatch broiler;and (b) TM during embryogenesis will improve myoblast proliferation during the embryonic and post-hatch periods with subsequent enhanced muscle growth and meat production. The original objectives of this study were as follow: 1. to assess the timing, temperature, duration, and turning frequency required for optimal TM during embryogenesis; 2. to evaluate the effect of TM during embryogenesis on thermoregulation (heat production and heat dissipation) during four phases: (1) embryogenesis, (2) at hatch, (3) during growth, and (4) during heat challenge near marketing age; 3. to investigate the stimulatory effect of thermotolerance on hormones that regulate thermogenesis and stress (T₄, T₃, corticosterone, glucagon); 4. to determine the effect of TM on performance (BW gain, feed intake, feed efficiency, carcass yield, breast muscle yield) of broiler chickens; and 5. to study the effect of TM during embryogenesis on skeletal muscle growth, including myoblast proliferation and fiber development, in the embryo and post-hatch chicks.This study has achieved all the original objectives. Only the plasma glucagon concentration (objective 3) was not measured as a result of technical obstacles. Background to the topic: Rapid growth rate has presented broiler chickens with seriousdifficulties when called upon to efficiently thermoregulate in hot environmental conditions. Being homeotherms, birds are able to maintain their body temperature (Tb) within a narrow range. An increase in Tb above the regulated range, as a result of exposure to environmental conditions and/or excessive metabolic heat production that often characterize broiler chickens, may lead to a potentially lethal cascade of irreversible thermoregulatory events. Exposure to temperature fluctuations during the perinatal period has been shown to lead to epigenetic temperature adaptation. The mechanism for this adaptation was based on the assumption that environmental factors, especially ambient temperature, have a strong influence on the determination of the “set-point” for physiological control systems during “critical developmental phases.” In order to sustain or even improve broiler performance, TM during the period of embryogenesis when satellite cell population normally expand should increase absolute pectoralis muscle weight in broilers post-hatch. Major conclusions: Intermittent TM (39.5°C for 12 h/day) during embryogenesis when the thyroid and adrenal axis was developing and maturing (E7 to E16 inclusive) had a long lasting thermoregulatory effect that improved thermotolerance of broiler chickens exposed to acute thermal stress at market age by lowering their functional Tb set point, thus lowering metabolic rate at hatch, improving sensible heat loss, and significantly decreasing the level of stress. Increased machine ventilation rate was required during TM so as to supply the oxygen required for the periods of increased embryonic development. Enhancing embryonic development was found to be accomplished by a combination of pre-incubation heating of embryos for 12 h at 30°C, followed by increasing incubation temperature to 38°C during the first 3 days of incubation. It was further facilitated by increasing turning frequency of the eggs to 48 or 96 times daily. TM during critical phases of muscle development in the late-term chick embryo (E16 to E18) for 3 or 6 hours (39.5°C) had an immediate stimulatory effect on myoblast proliferation that lasted for up to two weeks post-hatch; this was followed by increased hypertrophy at later ages. The various incubation temperatures and TM durations focused on the fine-tuning of muscle development and growth processes during late-term embryogenesis as well as in post-hatch chickens.
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Wolfenson, David, William W. Thatcher, Rina Meidan, Charles R. Staples, and Israel Flamenbaum. Hormonal and Nutritional Stretegies to Optimize Reproductive Function and Improve Fertility of Dairy Cattle during Heat Stress in Summer. United States Department of Agriculture, August 1994. http://dx.doi.org/10.32747/1994.7568773.bard.

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The BARD program includes two main parts. In the first, experiments were conducted to complete our understanding of the mechanisms responsible for the impairment of reproductive functions under heat stress. Experiments focused on follicular development and function, since results obtained in our previous BARD project indicate that the preovulatory follicle is susceptible to heat stress. The theca cells, sensitive to thermal stress, produced less androgen during the summer, as well as during the autumn. Similarly, luteinized theca cells obtained from cows in summer produced much less progesterone than in winter. Granulosa cells and luteinized granulosa cells were less susceptible to heat stress. A delayed effect of heat stress on follicular development, on suppression of dominance and on steroid production by theca and granulosa cells was noted. This may be related to the low fertility of cows during the cool months of autumn. In the second part, experiments were conducted aiming to improve fertility in summer. The timed AI program was developed using two injections of GnRH coupled with PGF2a. It was found effective in improving reproductive performance in lactating cows. Limitations induced by heat stress on estrus detection were eliminated with the timed AI management program. Replacing the second injection of GnRH with hCG instead of GnRH agonist increased plasma progesterone levels post ovulation but did not improve fertility. Use of the timed AI program in summer, shortened days open and increased the net revenue per cow, however, it did not protect the embryo fiom temperature-induced embryonic mortality. Incorporation of a GnRH-agonist implant into the timed AJ program was examined. The implant increased plasma progesterone and LH concentrations and altered follicular dynamics. The use of a GnRH-implant enhanced pregnancy rate in cows with low body conditions. In a timed embryo transfer experiment, the use of fresh or frozen in vitro produced embryos was compared in the summer to improve fertility. The use of flesh embryos (but not frozen ones) improved pregnancy rate, however, substantial embryonic death occurred between 21 and 45 days. The timed AI program, which is now being used commercially, shortened days open, and increased pregnancy rate during summer. Other approaches which were found to improve fertility in small-scale studies, need to be tested again in large-scale field trials.
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Agresar, Grenmarie, and Michael A. Savageau. Final Report, December, 1999. Sloan - US Department of Energy joint postdoctoral fellowship in computational molecular biology [Canonical nonlinear methods for modeling and analyzing gene circuits and spatial variations during pattern formation in embryonic development]. Office of Scientific and Technical Information (OSTI), December 1999. http://dx.doi.org/10.2172/811376.

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Uni, Zehava, and Peter Ferket. Enhancement of development of broilers and poults by in ovo feeding. United States Department of Agriculture, May 2006. http://dx.doi.org/10.32747/2006.7695878.bard.

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The specific objectives of this research were the study of the physical and nutritional properties of the In Ovo Feeding (IOF) solution (i.e. theosmostic properties and the carbohydrate: protein ratio composition). Then, using the optimal solution for determining its effect on hatchability, early nutritional status and intestinal development of broilers and turkey during the last quarter of incubation through to 7 days post-hatch (i.e. pre-post hatch period) by using molecular, biochemical and histological tools. The objective for the last research phase was the determination of the effect of in ovo feeding on growth performance and economically valuable production traits of broiler and turkey flocks reared under practical commercial conditions. The few days before- and- after hatch is a critical period for the development and survival of commercial broilers and turkeys. During this period chicks make the metabolic and physiological transition from egg nutriture (i.e. yolk) to exogenous feed. Late-term embryos and hatchlings may suffer a low glycogen status, especially when oxygen availability to the embryo is limited by low egg conductance or poor incubator ventilation. Much of the glycogen reserve in the late-term chicken embryo is utilized for hatching. Subsequently, the chick must rebuild that glycogen reserve by gluconeogenesis from body protein (mostly from the breast muscle) to support post-hatch thermoregulation and survival until the chicks are able to consume and utilize dietary nutrients. Immediately post-hatch, the chick draws from its limited body reserves and undergoes rapid physical and functional development of the gastrointestinal tract (GIT) in order to digest feed and assimilate nutrients. Because the intestine is the nutrient primary supply organ, the sooner it achieves this functional capacity, the sooner the young bird can utilize dietary nutrients and efficiently grow at its genetic potential and resist infectious and metabolic disease. Feeding the embryo when they consume the amniotic fluid (IOF idea and method) showed accelerated enteric development and elevated capacity to digest nutrients. By injecting a feeding solution into the embryonic amnion, the embryo naturally consume supplemental nutrients orally before hatching. This stimulates intestinal development to start earlier as was exhibited by elevated gene expression of several functional genes (brush border enzymes an transporters , elvated surface area, elevated mucin production . Moreover, supplying supplemental nutrients at a critical developmental stage by this in ovo feeding technology improves the hatchling’s nutritional status. In comparison to controls, administration of 1 ml of in ovo feeding solution, containing dextrin, maltose, sucrose and amino acids, into the amnion of the broiler embryo increased dramatically total liver glycogen in broilers and in turkeys in the pre-hatch period. In addition, an elevated relative breast muscle size (% of broiler BW) was observed in IOF chicks to be 6.5% greater at hatch and 7 days post-hatch in comparison to controls. Experiment have shown that IOF broilers and turkeys increased hatchling weights by 3% to 7% (P<0.05) over non injected controls. These responses depend upon the strain, the breeder hen age and in ovo feed composition. The weight advantage observed during the first week after hatch was found to be sustained at least through 35 days of age. Currently, research is done in order to adopt the knowledge for commercial practice.
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Hansen, Peter J., and Amir Arav. Embryo transfer as a tool for improving fertility of heat-stressed dairy cattle. United States Department of Agriculture, September 2007. http://dx.doi.org/10.32747/2007.7587730.bard.

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The overall objective of the current proposal is to develop procedures to improve the pregnancy rate achieved following transfer of fresh or cryopreserved embryos produced in the laboratory into heat-stress recipients. The overall hypothesis is that pregnancy rate in heat-stressed lactating cows can be improved by use of embryo transfer and that additional gains in pregnancy rate can be achieved through development of procedures to cryopreserve embryos, select embryos most likely to establish and maintain pregnancy after transfer, and to enhance embryo competence for post-transfer survival through manipulation of culture conditions. The original specific objectives were to 1) optimize procedures for cryopreservation (Israel/US), 2) develop procedures for identifying embryos with the greatest potential for development and survival using the remote monitoring system called EmbryoGuard (Israel), 3) perform field trials to test the efficacy of cryopreservation and the EmbryoGuard selection system for improving pregnancy rates in heat-stressed, lactating cows (US/Israel), 4) test whether selection of fresh or frozen-thawed blastocysts based on measurement of group II caspase activity is an effective means of increasing survival after cryopreservation and post-transfer pregnancy rate (US), and 5) identify genes in blastocysts induced by insulin-like growth factor-1 (IGF-1) (US). In addition to these objectives, additional work was carried out to determine additional cellular determinants of embryonic resistance to heat shock. There were several major achievements. Results of one experiment indicated that survival of embryos to freezing could be improved by treating embryos with cytochalasin B to disrupt the cytoskeleton. An additional improvement in the efficacy of embryo transfer for achieving pregnancy in heat-stressed cows follows from the finding that IGF-1 can improve post-transfer survival of in vitro produced embryos in the summer but not winter. Expression of several genes in the blastocyst was regulated by IGF-1 including IGF binding protein-3, desmocollin II, Na/K ATPase, Bax, heat shock protein 70 and IGF-1 receptor. These genes are likely candidates 1) for developing assays for selection of embryos for transfer and 2) as marker genes for improving culture conditions for embryo production. The fact that IGF-1 improved survival of embryos in heat-stressed recipients only is consistent with the hypothesis that IGF-1 confers cellular thermotolerance to bovine embryos. Other experiments confirmed this action of IGF-1. One action of IGF-1, the ability to block heat-shock induced apoptosis, was shown to be mediated through activation of the phosphatidylinositol 3-kinase pathway. Other cellular determinants of resistance of embryos to elevated temperature were identified including redox status of the embryo and the ceramide signaling pathway. Developmental changes in embryonic apoptosis responses in response to heat shock were described and found to include alterations in the capacity of the embryo to undergo caspase-9 and caspase-3 activation as well as events downstream from caspase-3 activation. With the exception of IGF-1, other possible treatments to improve pregnancy rate to embryo transfer were not effective including selection of embryos for caspase activity, treatment of recipients with GnRH.and bilateral transfer of twin embryos. In conclusion, accomplishments achieved during the grant period have resulted in methods for improving post-transfer survival of in vitro produced embryos transferred into heat-stressed cows and have lead to additional avenues for research to increase embryo resistance to elevated temperature and improve survival to cryopreservation. In addition, embryo transfer of vitrified IVF embryos increased significantly the pregnancy rate in repeated breeder cows.
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