Dissertations / Theses on the topic 'Embryonic development'
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Salanga, Matthew Charles. "EMBRYONIC VASCULAR DEVELOPMENT." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/203435.
Full textHarrison, 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.
Full textLosa, 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.
Full textVaahtokari, 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.
Full textShivji, Nadia. "GnRH neuron migration during embryonic development." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611556.
Full textJörg, 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.
Full textAbdullah, A. R. "Mathematical modelling of embryonic tissue development." Thesis, University of Liverpool, 2018. http://livrepository.liverpool.ac.uk/3028456/.
Full textCheung, Kwok Kuen. "Purinergic signaling during rat embryonic development." Thesis, University College London (University of London), 2004. http://discovery.ucl.ac.uk/1446895/.
Full textMeadows, Stryder. "Transcriptional Regulation In Early Embryonic Development." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/194034.
Full textSneesby, Kyra, and n/a. "Gene Expression in Embryonic Chick Heart Development." Griffith University. School of Biomolecular and Biomedical Science, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030924.153514.
Full textDumoulin, Johannes Christianus Marie. "Taurine and preimplantation embryonic development in vitro." Maastricht : Maastricht : Universitaire Pers Maastricht ; University Library, Maastricht University [Host], 1997. http://arno.unimaas.nl/show.cgi?fid=5937.
Full textPupavac, Mihaela. "Mmachc is required for mouse embryonic development." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104863.
Full textLa forme cblC de l'acidurie méthylmalonique et l'homocystinurie combinée (OMIM 277400) est la maladie génétique la plus fréquente affectant le métabolisme de la vitamine B12 (cobalamine, Cbl), avec plus de 500 patients identifiés à travers le monde. En raison de mutations dans le gène MMACHC, les patients atteints de cette maladie sont incapables de convertir la cobalamine en les deux formes actives, soit la méthylcobalamine et l'adénosylcobalamine, qui sont des cofacteurs requis par les enzymes mammifères méthionine synthase et methylmalonyl-CoA mutase, respectivement. Les symptômes cliniques des patients peuvent être de l'ordre hématologique, neurologique, ophtalmologique ou d'un retard de développement. Dans cette étude, l'importance de MMACHC durant le développement embryonnaire de la souris est examinée. Le gène Mmachc est démontré comme étant exprimé dans le mésenchyme de la tête, les ganglions de la racine dorsale, le cœur, la trachée, les poumons, l'œsophage, l'intestin, mésenchyme mésonéphrique et la notochorde au cours de l'organogenèse chez l'embryon de souris. Une mutation de type « genetrap » a été insérée dans l'intron 1 du gène Mmachc, noté MmachcGT1, afin de bloquer la production d'une protéine fonctionnelle MMACHC. Les souris adultes hétérozygotes pour le « genetrap » Mmachc se sont avérées être fertiles et viables, même si un pourcentage d'embryons hétérozygotes possédait un phénotype anormal. Les souris et embryons hétérozygotes pour l'allèle MmachcGT1 ont été trouvés dans un nombre plus élevé que prévu par les ratios mendéliens. Les embryons homozygotes pour MmachcGT1 n'ont été observés qu'au jour embryonnaire 3.5. Ces résultats démontrent que le gène Mmachc est essentiel au cours du développement embryonnaire de la souris.
Karunadasa, Delicia Kumari. "Embryonic development of GnRH and vomeronasal neurons." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615881.
Full textZhang, Xiaoxiao. "Cell Fate Decisions in Early Embryonic Development." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:10792.
Full textGill, Mark E. "Dazl regulates mouse embryonic germ cell development." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/58372.
Full textCataloged from PDF version of thesis.
Includes bibliographical references.
In the mouse, germ cells can undergo differentiation to become either oocytes or spermatozoa in response to sex of their gonadal environment. The nature of the germ cell-intrinsic aspects of this signaling have not been well studied. The earliest known sex-specific difference in germ cells is the initiation of meiosis in female, but not male, embryonic germ cells. Experiments were performed showing that germ cells of both sexes transit through a state, the meiosis competent germ cell, that is required for initiation of meiosis. Acquisition of this state requires the function of the germ cellspecific RNA binding protein DAZL. The sufficiency for the absence of meiosis to drive male germ cell differentiation was then tested by examining non-meiotic XX germ cells in the Dazl-deficient ovary. These cells did not exhibit male differentiation indicating that the absence of meiosis is not sufficient for male differentiation. XX Dazl-deficient germ cells also failed to exhibit normal female differentiation. In addition, XY Dazl-deficient germ cells do not display characteristics of either male or female germ cells. Taken together, these results indicate that germ cells must first undergo a sex non-specific differentiation step prior to acquiring sexual fate.
by Mark E. Gill.
Ph.D.
Yu, Xiang. "Wingless signal transduction during Drosophila embryonic development." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624339.
Full textSneesby, Kyra. "Gene Expression in Embryonic Chick Heart Development." Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367647.
Full textThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Biomedical Sciences
Full Text
Dubuis, Julien. "Quantifying positional information during early embryonic development." Paris 6, 2012. http://www.theses.fr/2012PA066388.
Full textKoontz, Deborah Ann. "Protein phosphorylation during embryonic development in the carrot." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/25596.
Full textSingh, Manvendra [Verfasser]. "Human endogenous retroviruses aid embryonic development / Manvendra Singh." Berlin : Freie Universität Berlin, 2019. http://d-nb.info/1181097703/34.
Full textHeinemann, Johannes [Verfasser], and Heike L. [Akademischer Betreuer] Pahl. "The role of Jmjd1c in murine embryonic development." Freiburg : Universität, 2017. http://d-nb.info/1182226027/34.
Full textSiu, Kwan-yin, and 蕭君言. "Expression studies of secretin during mouse embryonic development." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29188179.
Full textPai, Y. J. "The glycine cleavage system in embryonic brain development." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1471014/.
Full textSpikings, Emma Catherine. "Mitochondrial DNA replication in pre-implantation embryonic development." Thesis, University of Birmingham, 2007. http://etheses.bham.ac.uk//id/eprint/45/.
Full textSolimena, Michele, Jakob Suckale, Olivia Wendling, Jimmy Masjkur, Melanie Jäger, Carla Münster, Konstantinos Anastassiadis, and A. Francis Stewart. "PTBP1 Is Required for Embryonic Development before Gastrulation." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-191525.
Full textMcNeil, Paul. "Environmental effects on the embryonic development of zebrafish." Thesis, University of the West of Scotland, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.731773.
Full textPinson, Jeni. "The role of Pax6 isoforms in embryonic development." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/29944.
Full textMcCoski, Sarah R. "Manipulating Embryonic Development and Endometrial Function in Ruminants." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/94375.
Full textPh. D.
Solimena, Michele, Jakob Suckale, Olivia Wendling, Jimmy Masjkur, Melanie Jäger, Carla Münster, Konstantinos Anastassiadis, and A. Francis Stewart. "PTBP1 Is Required for Embryonic Development before Gastrulation." Public Library of Science, 2011. https://tud.qucosa.de/id/qucosa%3A29128.
Full textBrown, Jessie Ann. "RUNX2 in Embryonic Heart Development and Heart Disease." Thesis, The University of Arizona, 2011. http://hdl.handle.net/10150/144250.
Full textTeperek, Marta. "Programming of the paternal nucleus for embryonic development." Thesis, University of Cambridge, 2016. https://www.repository.cam.ac.uk/handle/1810/262228.
Full textPonomarenko, Ekaterina. "The embryonic development of Elminius modestus Darwin, 1854." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2014. http://dx.doi.org/10.18452/17006.
Full textThe present work is devoted to the embryonic development of the thoracican barnacle Elminius modestus (Thecostraca: Cirripedia). The developmental process was investigated by means of different techniques like 4D microscopy, in vivo labelling, fluorescent histochemistry, and confocal laser scanning microscopy combined with 3D reconstructions. The cleavage of E. modestus is total, unequal with regards to the yolky cell, and asynchronous with an anterior-posterior gradient. The entire process appears to follow a strict pattern of divisions with very little variability, one of which includes the occurrence of mirror image embryos from the 4-cell stage on. The germ layer differentiation was mainly studied by means of in vivo labelling. The segregation of the endodermal and the endomesodemal germ layers are shown to happen after the fourth division, whereas the ectomesoderm segregates after the sixth division. The primordial germ cells are suggested to be a product of the seventh cleavage division of the yolky cells (3Da and 3Dp). During the research the cell lineage of each germ layer was established, the fates of the quadrant descendants are described up to the 16-cell stage. The ectoderm originates from four quadrants, as does the ectomesoderm (the last identified mesectoblasts are 3A, 3B, 3C, 1drp, and 1dlp). The endoderm and the endomesoderm develop from single precursors at the 16-cell stage (2D and 2d, respectively). The presence of only a single endoblastic cell, might represent an apomorphy for the entire group of Ecdysozoa. A singular mesendoblast is suggested to be a possible feature in the developmental ground pattern of all Protostomia.
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.
Full textMaster of Science
Psychoyos, Delphine. "Regeneration of the organizer." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299176.
Full textCanning, David Richard. "The mechanisms of formation of the embryonic axis." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329968.
Full textSchacker, Maria Anna. "Defining the transcriptional and epigenetic signature of mouse embryonic stem cells with compromised developmental potency." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/287725.
Full textBasuki, Edi 1957. "Ecdysteroid levels and implications for embryonic and post-embryonic development of the blowfly Lucilia cuprina (Wied.) (Diptera:Calliphoridae)." Monash University, Dept. of Biological Sciences, 2000. http://arrow.monash.edu.au/hdl/1959.1/8436.
Full textBrigden, Kurt. "Copper transporters in development." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17116.
Full textVrljičak, Pavle Josip. "Genomic analysis of embryonic heart development in the mouse." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/28814.
Full textSaad, Kawakeb Ali Omran. "The function and regulation of glypicans during embryonic development." Thesis, University of Reading, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627646.
Full textCheung, Ka-chun, and 張家進. "Roles of makorin-2 in embryonic development and carcinogenesis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45595197.
Full textAllcorn, Suzette. "Neurotransmitters and the development of the embryonic chick retina." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309514.
Full textHolm, Teresa M. "The role of imprinting in embryonic development and tumorigenesis." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/34187.
Full textIncludes bibliographical references (v. 2, leaves 150-197).
Imprinting is a mammalian adaptation that results in the mono-allelic expression of a subset of genes depending on their parental origin. It is believed that DNA methylation marks are responsible for maintaining imprinted gene expression patterns. The 'parental conflict' hypothesis was proposed to explain the evolution of imprinting and is based on the assumption that mammals arose from an ancestor that was polyandrous (multiple fathers within one litter). According to this hypothesis, conflict between the male and female over the allocation of maternal resources to the offspring led to the evolution of imprinting. Consistent with this, many imprinted genes are involved in embryonic or placental growth by regulating mitogenic pathways or the cell cycle. Loss of imprinting (LOI) has been found at specific loci in cancers, raising the possibility that altered expression of imprinted genes may also contribute to tumorigenesis. To investigate the effect of global LOI on embryonic development and cancer formation, imprint free (IF) embryonic stem (ES) cells were generated using conditional inactivation/reactivation of the DNA methyltransferase Dnmtl. Tetraploid complementation and chimera experiments revealed that IF-embryos fail to develop beyond E11.5 and display an overgrowth phenotype.
(cont.) As developmental comparisons, parthenogenetic and androgenetic (AT) embryos were derived and found to develop to E9.5 and E7.5, respectively. Removing the imprinted methyl marks from AT-ES cells rescued embryonic development to E9.5-10.5 and restored pluripotency. However, IFAT embryos were not developmentally equivalent to biparentally-derived IF-embryos, suggesting that mechanisms other than DNA methylation may be involved in maintaining parent-specific gene expression patterns. To study the effect of LOI on cell growth, murine embryonic fibroblasts (MEFs) were derived from E13.5 chimeric IF-embryos and analyzed in vitro. IF-MEFs grew faster, were resistant to the cytostatic effects of TGFI3, and formed tumors in SCID mice. In addition, IF-MEFs were immortal and when exposed to H-Ras became fully transformed. Western blot analysis of IF-MEFs revealed abnormally low levels of p19Arf and p53, two critical regulators of growth arrest and potent tumor suppressors. Somatic contribution of IF-ES cells in chimeric adults led to highly penetrant tumor formation by 12 months of age, causing multiple cancer types derived from the IF cells. Taken together, these data are consistent with global LOI having a causal role in tumorigenesis by affecting the regulation of the p53-p19Ar pathway and predisposing IF cells to transformation.
by Teresa M. Holm.
Ph.D.
Page, Damon Theron. "Development and evolution of the embryonic brain in Drosophila." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619556.
Full textPrieto, Godino Laura Lucía. "Embryonic development of the olfactory system in Drosophila melanogaster." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609400.
Full textBrand, Zanell. "Studies on embryonic development and hatchability of ostrich eggs." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20314.
Full textENGLISH ABSTRACT: The ostrich industry experiences high rates of embryonic mortalities during artificial incubation of eggs. Studies have been carried out to investigate factors influencing hatchability, as well as determining genotypic effects for commercial production. Eggs from the combination of South African Black (SAB) male ostriches crossed with Zimbabwean Blue (ZB) female ostriches had embryonic losses of 45.7%. The embryonic mortality of eggs produced by pure bred SAB or ZB breeding birds subjected to pure breeding was similar at around 33 - 34%, but embryonic mortality was improved in eggs produced by ZB males and SAB female crosses (27%). Female age had a significant effect on the proportion of chicks pipped, as well as on early and late the embryonic mortalities. Chicks from eggs stored for intermediate periods, i.e. 3, 4 and 6 days prior to being set, were more likely to pip than chicks from those eggs set directly after collection without storage. Embryonic mortality was increased in eggs that were set directly (32.0%) or subjected to longer than 6 days of storage (43.5%). Chicks that pipped in the correct position had a higher probability of successfully hatching than those pipping in the incorrect position. Transfer of eggs between setters (i.e. disturbance of eggs) during incubation reduced the number of ostrich chicks pipping in the correct position. Incubated ostrich eggs with intermediate levels of water loss, i.e. between 9.0 and 19% of fresh egg weight, were more likely to pip in the correct position than those with higher or lower levels of water loss. Such eggs were also less likely to sustain early, late or overall embryonic mortalities. To optimise hatching success it is important to understand embryonic development. After 2 days of incubation the blastoderm area in eggs from the SAB x ZB crosses (104.5 mm) was lower (P < 0.05) compared to the pure SAB (141.0 mm), pure ZB (161.7 mm) and ZB x SAB crosses (166.1 mm). For embryos incubated for 7 to 42 days, both embryonic and leg growth during the 42 days of incubation was similar and approximately linear, more or less doubling in size up to 35 days of incubation. The embryo eye size increased more rapidly than beak length and reached full size of approximately 16.2 mm by 28 days of incubation, whereas the beak length continued to increase until the chick hatched at 42 days. Incubation position, vertical or horizontal, did not affect any of the measurements of the developing embryo throughout the 42-day incubation period. Air cell volume at 29 day of incubation for infertile eggs (19.3%) was significantly (P < 0.05) higher when compared to dead-in-shell eggs (14.3%) and eggs that hatched successfully (13.8%). Air cell volume was largely independent of strain (SAB or ZB) and whether chicks were assisted to hatch or not. After 41 days of incubation there was a significantly greater (P < 0.05) air cell volume in eggs that hatched normally compared to dead-in-shell eggs (28.3% vs. 21.7%, respectively, suggesting that insufficient water loss contributed to reduced survival. This study provides an insight into the complexity of embryo development and all the factors playing a role in successful hatching of ostrich eggs. Data from a pair-mated ostrich flock were used to estimate genetic parameters for egg weight (EWT), weight of day-old chicks (CWT), water loss to 21 (WL21) and 35 (WL35) days of incubation, and pipping time (PT). Single-trait estimates of heritability (h2) were high and significant (P < 0.05) at 0.46 for EWT, 0.34 for CWT, 0.34 for WL21, 0.27 for WL35 and 0.16 for pipping time. Genetic correlations with EWT amounted to -0.21 for WL21 and to -0.12 for WL35. Corresponding correlations of CWT with WL were highly significant (P < 0.05) at -0.43 and -0.54. Physical characteristics of the eggshell were found to affect water loss and hatchability. Estimates of genetic parameters of 14 146 ostrich eggs for eggshell traits showed that heritability was 0.42 for pore count (PC), 0.33 for shell thickness (ST) and 0.22 for permeability (PERM). PC was negatively correlated with average pore diameter (-0.58) and ST (-0.23), while PC was positively correlated with total pore area (0.58), WL21 (0.24) and WL35 (0.34). The correlations of PC with total pore area and PERM were high and significant. ST was negatively correlated to WL21 and WL35. Additive genetic parameters strongly indicate that it should be possible to alter evaporative water loss and eggshell quality of ostrich eggs through genetic selection. When assessed as a trait of the individual egg or chick, embryonic mortalities exhibited moderate levels of genetic variation both on the normal scale (h2 = 0.16 - 0.22) and the underlying liability scale (h2 = 0.21 - 0.31). Early embryonic survival and late embryonic survival was governed mostly by the same genes (rg = 0.78). Late embryonic survival was genetically correlated to WL35, at -0.22. It was concluded that embryonic survival could be improved by using husbandry measures, a knowledge of the stage when incubation mortalities occur, and by genetic selection, using an integrated approach. Findings from this study will help to understand the mechanisms involved in hatching from artificial incubation better to improve hatchability and also implement selective breeding programs.
AFRIKAANSE OPSOMMING: Die volstruisbedryf ondervind tans ‘n baie hoë voorkoms van embrionale mortaliteite tydens die kunsmatige uitbroei van eiers. Studies is uitgevoer om die faktore wat uitbroeibaarheid beinvloed te ondersoek en om genotipiese effekte te bepaal vir kommersiële produsente. Eiers van die kombinasie van Suid-Afrikaanse swart (SAB) mannetjie volstruise, met Zimbabwean blou (ZB) wyfies, het embrionale mortaliteite van 45.7% gehad. Embrionale mortaliteite van eiers gelê deur suiwer SAB of ZB volstruise was dieselfde op omtrent 33 - 34%, maar embrionale mortaliteite was laer vir eiers geproduseer deur SAB wyfies wat gekruis was met ZB mannetjies (27%). Wyfie ouderdom het ‘n betekenisvolle effek gehad op die proporsie van kuikens wat gepik het, asook die aantal vroeë- en laat embrionale mortaliteite. Kuikens vanuit eiers wat vir die periode 3, 4 dae en 6 dae voor pak in die broeikaste gestoor is, was meer geneig om te pik as kuikens vanaf eiers wat direk na kolleksie gepak is. Embrionale mortalitiete het verhoog vir eiers wat direk na kolleksie gepak was (32.0%) of vir eiers wat langer as 6 dae gestoor was (43.5%). Kuikens wat in die korrekte posisie pik het ‘n hoër kans op uitbroei gehad as kuikens wat in die verkeerde posisie gepik het. Die skuif van eiers tussen verskillende broeikaste (of enige steurnisse) gedurende die broeiproses het ‘n verlaging in die aantal kuikens wat in die korrekte posisie pik, gehad. Volstruiseiers met ‘n gemiddelde vogverlies van tussen 9.0 en 19% van die vars eier massa, was meer geneig om in die korrekte posisie te pik as eiers met laer of hoër vlakke van vogverlies. Sulke eiers was ook minder geneig tot vroeë, laat en totale embrionale mortaliteite. Vir optimale uitbroeisukses is dit belangrik om die ontwikkeling van die embrio te verstaan. Na 2 dae van broei was die blastoderm area in eiers van SAB x ZB kruisings (104.5 mm) kleiner (P < 0.05) as die blastoderm area van suiwer SAB (141.0 mm), suiwer ZB (161.7 mm) en ZB x SAB kruise (166.1 mm). Beide embrionale- en beengroei tydens die 42 dae broeiproses was dieselfde en nagenoeg lineêr, met ‘n verdubbeling in grootte tot en met 35 dae broei. Die embrio se oog vergroot vinniger as wat die snawel verleng en bereik reeds volle grootte van ongeveer 16.2 mm op 28 dae van broei, terwyl die snawel aanhou groei tot uitbroei van die kuiken op 42 dae. Nie die vertikale of horisontale broeiposisie het enige invloed op die metings van die ontwikkelende embrio tot op 42 dae gehad nie. Lugsakvolume vir geil eiers (19.3%) op 29 dae van broei was groter (P < 0.05) as beide die lugsakke van eiers wat dood-in-dop (14.3%) en eiers wat suksesvol uitgebroei het (13.8%). Die lugsakvolume was onafhanklik van beide genotype en of die kuiken met of sonder hulp uitgebroei het. Na 41 dae broei was lugsakvolume groter (P < 0.05) vir eiers wat uitgebroei het teenoor eiers wat dood-in-dop was (28.3% vs. 21.7%, onderskeidelik), wat impliseer dat onvoldoende vogverlies moontlik kan bydrae tot ‘n verlaging in embrionale oorlewing. Hierdie studie gee ‘n insig in die kompleksiteit van embrionale ontwikkeling en al die faktore wat ‘n rol speel in die suksesvolle uitbroei van volstruiseiers. Tydens die bepaling van genetiese parameters vir spesifieke uitbroei-eienskappe in volstruise, is data gebruik afkomend van ‘n teelkudde in ‘n enkelparing stelsel om genetiese waardes vir eiermassa (EWT), dagoud kuikenmassa (CWT), vogverlies tot 21 dae broei (WL21), vogverlies tot 35 dae broei (WL35) en piktyd (PT) gebruik. Enkeleienskap-beraming vir oorerflikheid (h2) was hoog en betekenisvol teen 0.46 vir EWT, 0.34 vir CWT, 0.34 vir WL21, 0.27 vir WL35 en 0.16 vir piktyd. Genetiese korrelasies met EWT was -0.21 vir WL21 en -0.12 vir WL35. Ooreenkomstig was korrelasies van CWT met WL21 en WL35 hoog (P < 0.05) met -0.43 en -0.54 onderskeidelik. Fisiese eienskappe van die eiers het beide vogverlies en uitbroeibaarheid beinvloed. Beramings van genetiese parameters vir 14 146 volstruiseiers se dopeienskappe het gewys dat oorerflikehid 0.42 was vir die aantal porieë (PC), 0.33 vir dopdikte (ST) en 0.22 vir deurlaatbaarheid (PERM). PC was negatief gekorreleerd met gemiddelde porieë deursnee (-0.58) en ST (-0.23), terwyl PC positief gekorreleerd was met totale porieë area (0.58), WL21 (0.24) en WL35 (0.34). Die korrelasie van PC met totale porieë area en deurlaatbaarheid was hoog en betekenisvol. ST was negatief gekorreleerd met WL21 en WL35. Additiewe genetiese parameters het sterk daarop gedui dat dit moontlik sou wees om vogverlies en eierkwaliteit (bv. dopkwaliteit en poreusiteit) van volstruiseiers te verander deur genetiese seleksie. Indien embrionale mortaliteit geevalueer word as ‘n kenmerk van die eier of kuiken, toon dit matige vlakke van genetiese variasie op beide die normale (h2 = 0.16 - 0.22) en die onderliggende skale (h2 = 0.21 - 0.31). Beide vroeë- en laat embrionale oorlewing word deur dieselfde stel gene beheer (rg = 0.78). Laat embrionale oorlewing was geneties gekorreleerd met WL35 teen -0.22. Die gevolgtrekking was dat embrionale oorlewing verbeter kan word deur verbeterde broeikamerpraktyke, kennis van op watter stadium van ontwikkelings embrionale mortaliteite plaasvind en deur genetiese seleksie. Bevindinge vanuit hierdie studies sal help om die meganismes betrokke by die kunsmatige uitbroei van volstruiskuikens beter te verstaan om sodoende uitbroeibaarheid te verbeter en ook suksesvolle seleksie programme te implementeer.
Shah, Nupur R. "Functional studies of YAP1 in cancer and embryonic development." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=238733.
Full textLam, Chi Man. "The regulation of Sox3 function in zebrafish embryonic development." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/37930/.
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