Littérature scientifique sur le sujet « Non-Embryonic development »
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Sommaire
Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Non-Embryonic development ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Articles de revues sur le sujet "Non-Embryonic development"
1
Hanlon, Caitlin D., et Deborah J. Andrew. « Drosophila FoxL1 non-autonomously coordinates organ placement during embryonic development ». Developmental Biology 419, no 2 (novembre 2016) : 273–84. http://dx.doi.org/10.1016/j.ydbio.2016.09.007.
Texte intégral
2
Yamauchi, Yasuhiro, Jeffrey A. Shaman et W. Steven Ward. « Non-genetic contributions of the sperm nucleus to embryonic development ». Asian Journal of Andrology 13, no 1 (18 octobre 2010) : 31–35. http://dx.doi.org/10.1038/aja.2010.75.
Texte intégral
3
Silva, Elisa Sant'Anna Monteiro da, José Carlos de Figueiredo Pantoja, José Nicolau Próspero Puoli et Cezinande Meira. « Ultrasonography of the conceptus development from days 15 to 60 of pregnancy in non-cyclic recipient mares ». Ciência Rural 45, no 3 (mars 2015) : 512–18. http://dx.doi.org/10.1590/0103-8478cr20140517.
Texte intégralRésumé :
The present study evaluated the development of equine conceptus transferred to non-cyclic recipient mares treated with altrenogest. Twenty four mares were used as embryo recipients during the ovulatory phase (Control group; n=8) or anestrus/transitional phases (Altrenogest group; n=16) and were evaluated by transrectal ultrasonography, at five day intervals, to monitor the development of embryonic vesicles from 15 to 45 days of pregnancy and embryo proper/fetus from 20 to 60 days. Embryonic vesicle's features such as shape, embryo location within the vesicle and umbilical cord development were similar between cyclic and non-cyclic recipient mares. The embryonic vesicle and embryo proper/fetus growth was significant (P<0.05) between 15 and 60 days of gestation in Altrenogest and Control groups, except for days 20 to 30, where embryonic vesicle growth decrease was observed (P>0.05). The embryonic vesicle and embryo proper/fetus growth was similar (P>0.05) when gestational days were compared between groups. The similarity in conceptus growth between cyclic and non-cyclic recipient mares during early pregnancy indicates that the uterine environment of non-cyclic recipient mares treated with progestins provides similar conditions for the development of transferred embryos
4
Al-Roubaie, Sarah, Espen D. Jahnsen, Masud Mohammed, Caitlin Henderson-Toth et Elizabeth A. V. Jones. « Rheology of embryonic avian blood ». American Journal of Physiology-Heart and Circulatory Physiology 301, no 6 (décembre 2011) : H2473—H2481. http://dx.doi.org/10.1152/ajpheart.00475.2011.
Texte intégralRésumé :
Shear stress, a mechanical force created by blood flow, is known to affect the developing cardiovascular system. Shear stress is a function of both shear rate and viscosity. While established techniques for measuring shear rate in embryos have been developed, the viscosity of embryonic blood has never been known but always assumed to be like adult blood. Blood is a non-Newtonian fluid, where the relationship between shear rate and shear stress is nonlinear. In this work, we analyzed the non-Newtonian behavior of embryonic chicken blood using a microviscometer and present the apparent viscosity at different hematocrits, different shear rates, and at different stages during development from 4 days (Hamburger-Hamilton stage 22) to 8 days (about Hamburger-Hamilton stage 34) of incubation. We chose the chicken embryo since it has become a common animal model for studying hemodynamics in the developing cardiovascular system. We found that the hematocrit increases with the stage of development. The viscosity of embryonic avian blood in all developmental stages studied was shear rate dependent and behaved in a non-Newtonian manner similar to that of adult blood. The range of shear rates and hematocrits at which non-Newtonian behavior was observed is, however, outside the physiological range for the larger vessels of the embryo. Under low shear stress conditions, the spherical nucleated blood cells that make up embryonic blood formed into small aggregates of cells. We found that the apparent blood viscosity decreases at a given hematocrit during embryonic development, not due to changes in protein composition of the plasma but possibly due to the changes in cellular composition of embryonic blood. This decrease in apparent viscosity was only visible at high hematocrit. At physiological values of hematocrit, embryonic blood viscosity did not change significantly with the stage of development.
5
Coomans, August, Gaëtan Borgonie et Kim Jacobsen. « Embryonic lineage evolution in nematodes ». Nematology 2, no 1 (2000) : 65–69. http://dx.doi.org/10.1163/156854100508908.
Texte intégralRésumé :
AbstractBecause of the high number of species and its ancient roots in evolution, the phylum Nematoda is well suited for comparative embryonic study. Using 4D microscopy we have reconstructed the embryonic lineages of several nematodes. This allows us to identify changing developmental strategies in the phylum Nematoda. Generally there has been a shift in the phylum from a non-determined, non-strict development to a faster, highly determined embryonic development. En raison du nombre élevé d’espèces et de ses racines anciennes dans l’évolution, le phylum Nematoda est bien approprié à des études d’embryologie comparée. A l’aide d’un microscope 4D, les lignages embryonnaires de plusieurs nématodes ont été reconstruits. Cela nous a permis d’identifier les modifications de stratégie développementales dans le phylum. Généralement, il y a eu un changement dans le phylum depuis un développement non déterminé et non précis jusqu’à un développement embryonnaire très rapide et hautement déterminé.
6
Rossant, Janet. « Stem cells and lineage development in the mammalian blastocyst ». Reproduction, Fertility and Development 19, no 1 (2007) : 111. http://dx.doi.org/10.1071/rd06125.
Texte intégralRésumé :
The mammalian blastocyst is the source of the most pluripotent stem cells known: embryonic stem (ES) cells. However, ES cells are not totipotent; in mouse chimeras, they do not contribute to extra-embryonic cell types of the trophectoderm (TE) and primitive endoderm (PrE) lineages. Understanding the genetic pathways that control pluripotency v. extra-embryonic lineage restriction is key to understanding not only normal embryonic development, but also how to reprogramme adult cells to pluripotency. The trophectoderm and primitive endoderm lineages also provide the first signals that drive patterned differentiation of the pluripotent epiblast cells of the embryo. My laboratory has produced permanent mouse cell lines from both the TE and the PrE, termed trophoblast stem (TS) and eXtra-embryonic ENdoderm (XEN) cells. We have used these cells to explore the genetic and molecular hierarchy of lineage restriction and identify the key factors that distinguish the ES cell v. the TS or XEN cell fate. The major molecular pathways of lineage commitment defined in mouse embryos and stem cells are probably conserved across mammalian species, but more comparative studies of lineage development in embryos of non-rodent mammals will likely yield interesting differences in terms of timing and details.
7
Zhou, Chune. « Knockdown of Novel lncRNA TCONS_00028652 in Zebrafish Affects Embryonic Vasculature Development ». International Journal of Agriculture and Biology 25, no 04 (1 avril 2021) : 831–37. http://dx.doi.org/10.17957/ijab/15.1735.
Texte intégralRésumé :
Long non-coding RNAs (lncRNA) are increasingly being regard as potential key regulators of biological process, however, little is known about the function of most of them. The involvement of a novel lncRNA (ENSDART000000150571), previously named TCONS_00028652, in intersegmental vessel development was investigated in this study. TCONS_00028652, having a single exon (568 bp), is located in chromosome 16 at position from 15786804 to 15786237, which was previously identified as an embryonic and adult heart-enrichedlncRNA. Bioinformatics analysis and annotation of TCONS_00028652 was performed using online databases. Its protein-coding potential was assessed using online softwares: the Coding Potential Assessing Tool (CPAT) and the Coding Potential Calculator (CPC). To verify its real existence, a cloned fragment was proliferated by designing primers against 5’ and 3’ exon-flanking sequence. Subsequently, spatiotemporal expression during zebrafish embryonic development was determined using real-time quantitative PCR (qPCR) and whole mount in situ hybridization. We found that lncRNA TCONS_00028652 was generally expressed throughout early stages of zebrafish embryonic development and predominantly in embryonic brain, tail, and heart. Knockdown of TCONS_00028652 using morpholino oligonucleotides (MO) resulted in intersegmental vessel defects, suggesting that TCONS_00028652 is indispensable for embryonic vascular development in zebrafish. Using Tg (flil:EGFP) transgenic fish expressing a cardiovascular marker gene, loss of function experiments confirmed that TCONS_00028652 was involved in embryonic intersegmental vessel development. Our results may lead to valuable understanding of lncRNAs functions in zebrafish embryonic development and molecular mechanisms of embryonic cardiovascular development. © 2021 Friends Science Publishers
8
Roeszler, Kelly. « Analysis of the long non-coding RNA, MHM, in avian embryonic development ». Developmental Biology 356, no 1 (août 2011) : 154. http://dx.doi.org/10.1016/j.ydbio.2011.05.186.
Texte intégral
9
Li, An et Zhang. « The Dynamic 3D Genome in Gametogenesis and Early Embryonic Development ». Cells 8, no 8 (29 juillet 2019) : 788. http://dx.doi.org/10.3390/cells8080788.
Texte intégralRésumé :
During gametogenesis and early embryonic development, the chromatin architecture changes dramatically, and both the transcriptomic and epigenomic landscape are comprehensively reprogrammed. Understanding these processes is the holy grail in developmental biology and a key step towards evolution. The 3D conformation of chromatin plays a central role in the organization and function of nuclei. Recently, the dynamics of chromatin structures have been profiled in many model and non-model systems, from insects to mammals, resulting in an interesting comparison. In this review, we first introduce the research methods of 3D chromatin structure with low-input material suitable for embryonic study. Then, the dynamics of 3D chromatin architectures during gametogenesis and early embryonic development is summarized and compared between species. Finally, we discuss the possible mechanisms for triggering the formation of genome 3D conformation in early development.
10
Ohazama, A., S. A. C. Modino, I. Miletich et P. T. Sharpe. « Stem-cell-based Tissue Engineering of Murine Teeth ». Journal of Dental Research 83, no 7 (juillet 2004) : 518–22. http://dx.doi.org/10.1177/154405910408300702.
Texte intégralRésumé :
Teeth develop from reciprocal interactions between mesenchyme cells and epithelium, where the epithelium provides the instructive information for initiation. Based on these initial tissue interactions, we have replaced the mesenchyme cells with mesenchyme created by aggregation of cultured non-dental stem cells in mice. Recombinations between non-dental cell-derived mesenchyme and embryonic oral epithelium stimulate an odontogenic response in the stem cells. Embryonic stem cells, neural stem cells, and adult bone-marrow-derived cells all responded by expressing odontogenic genes. Transfer of recombinations into adult renal capsules resulted in the development of tooth structures and associated bone. Moreover, transfer of embryonic tooth primordia into the adult jaw resulted in development of tooth structures, showing that an embryonic primordium can develop in its adult environment. These results thus provide a significant advance toward the creation of artificial embryonic tooth primordia from cultured cells that can be used to replace missing teeth following transplantation into the adult mouth.
Thèses sur le sujet "Non-Embryonic development"
1
Vasilopoulos, Georgios. « Local and non-local mathematical modelling of signalling during embryonic development ». Thesis, Heriot-Watt University, 2012. http://hdl.handle.net/10399/2574.
Texte intégralRésumé :
Embryonic development requires cells to communicate as they arrange into the adult organs and tissues. The ability of cells to sense their environment, respond to signals and self-organise is of crucial importance. Patterns of cells adopting distinct states of differentiation arise in early development, as a result of cell signalling. Furthermore, cells interact with each other in order to form aggregations or rearrange themselves via cell-cell adhesion. The distance over which cells can detect their surroundings plays an important role to the form of patterns to be developed, as well as the time necessary for developmental processes to complete. Cells achieve long range communication through the use of extensions such as filopodia. In this work we formulate and analyse various mathematical models incorporating long-range signalling. We first consider a spatially discrete model for juxtacrine signalling extended to include filopodial action. We show that a wide variety of patterns can arise through this mechanism, including single isolated cells within a large region or contiguous blocks of cells selected for a specific fate. Cell-cell adhesion modelling is addressed in this work. We propose a variety of discrete models from which continuous models are derived. We examine the models’ potential to describe cell-cell adhesion and the associated phenomena such as cell aggregation. By extending these models to consider long range cell interactions we were able to demonstrate their ability to reproduce biologically relevant patterns. Finally, we consider an application of cell adhesion modelling by attempting to reproduce a specific developmental event, the formation of sympathetic ganglia.
2
Tobias, Santos Vitória. « A Transcriptome-Level Comparison of Independently Evolved Non-Embryonic Development in Different Species of Styelidae (Tunicata) ». Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS401.pdf.
Texte intégralRésumé :
Les tuniciers (Chordata) sont les plus proches des vertébrés capables de régénérer leur corps entier (WBR pour Whole Body Regeneration) lors de blessures graves ou dans le cadre de leur cycle de reproduction asexuée. Chez différents tuniciers, la WBR est initiée par divers tissus non-homologues d’une espèce à l’autre, incluant le recrutement de cellules souches mésenchymateuses et/ou la dé/transdifférenciation de certains épithéliums. Néanmoins, les dynamiques cellulaires et les mécanismes moléculaires qui sous-tendent la WBR restent encore méconnus. Pour mieux comprendre les différences et les points communs entre différents modes de WBR acquis indépendamment, j’étudie la famille des Stylidae chez laquelle j'ai sélectionné deux espèces de tuniciers maintenues en laboratoire et qui ont développé de manière convergente la capacité de WBR: Botryllus schlosseri et Polyandrocarpa zorritensis. J'ai mis au point une technique de marquage fluorescent in vivo qui m'a permis d'obtenir le profil transcriptomique (RNAseq) de sept stades clefs de la WBR chez P. zorritensis. L'analyse différentielle de l'expression des gènes a révélé des groupes de gènes associés à chaque étape, de l'initiation de la WBR au début de la morphogenèse. Je compare maintenant ces résultats avec des jeux de données RNAseq de WBR chez d'autres espèces de tuniciers (B. schlosseri, B. leachii et P. misakiensis) en tirant parti des données transcriptomiques disponibles ainsi que des données génomiques de haute qualité récemment obtenus par notre équipe. Grâce à cela j’ai commencé à identifier des gènes orthologues partageant une expression dynamique au cours de différents modes de WBR acquis de manière convergente au cours de l’évolution. Une exploration plus approfondie du patron d'expression de ces gènes chez ces espèces me permettra de mieux comprendre les mécanismes sous-jacents à l'évolution plastique de la WBR chez les chordésTunicates (Chordata) are the closest relative to vertebrates able to undergo whole-body regeneration (WBR) upon severe injury or as part of their asexual life cycle. In different tunicate species, WBR starts from various non-homologous epithelia or mesenchymal cells, which either home adult stem cells or undergo de/transdifferentiation. The cell dynamics and the molecular players behind WBR are still elusive. To better understand differences and commonalities between independently evolved WBRs, I focused on the family of Styelidae, in which I selected two tunicate laboratory-reared species that independently evolved the capacity of WBR: Botryllus schlosseri and Polyandrocarpa zorritensis. Taking advantage of our previous morphological characterization of P. zorritensis WBR, I adapted a live-staining technique that allowed me to obtain the transcriptomic profile of seven informative stages of WBR in this species. Differential gene expression analysis revealed clusters of genes associated with each stage, from WBR initiation to the onset of morphogenesis. I’m now comparing these results with published and in-house RNAseq datasets of WBR in other species of tunicate (B. schlosseri, B. leachii, and P. misakiensis) taking advantage of available transcriptomic data as well as high quality genome data recently obtained by our team. This started to lead to the identification of orthologous genes sharing a dynamic expression during convergently acquired WBR. Further exploration of the expression pattern of these genes across species will allow us to identify common and different mechanisms underlying the plastic evolution of WBR in chordates
3
Scelzo, Marta. « Vasal budding : characterization of a new form of non-embryonic development in the colonial ascidian Polyandrocarpa zorritensis ». Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS467.
Texte intégralRésumé :
Les tuniciers coloniaux peuvent générer un nouveau corps par reproduction asexuée et par la régénération entière du corps, deux formes de développement non-embryonnaire (DNE). Les différents modes de DNE sont définis en fonction de la nature des tissus organogénétiques. Curieusement, cette capacité est dispersée au sein du sous-phylum, qui contient des espèces capables de DNE (colonial) proches phylogénétiquement d’espèces ou les capacités régénératives sont absentes ou réduites (solitaire). Cela suggère que le DNE a été acquis et perdu plusieurs fois au sein du groupe. L’espèce coloniale Polyandrocarpa zorritensis semble avoir indépendamment acquis la capacité de DNE. Au cours de ma thèse, j’ai caractérisé le DNE dans cette espèce, en identifiant les étapes de DNE en conditions de laboratoire ainsi que les tissus et cellules mises en jeu. J’ai mis en évidence la participation des cellules mesenchymales et de l’épithélium vasculaire dans ce type de DNE. Ça n’a été pas décrit auparavant, et nous avons décidé de l’appeler ‘bourgeonnement vasale’. J’ai observé des cellules mesenchymales non-différenciées se regrouper et proliférer au point de régénération. J’ai décrit les cellules mesenchymales, en identifiant dans les cellules qui prolifèrent un morphotype non-différencié, les hémoblastes, aussi connues comme étant des cellules-souches putatives chez d’autres ascidies coloniales. De plus, j’ai défini la présence d’une étape de quiescence, la sphérule, dans le cycle de vie de P. zorritensis et j’ai caractérisé les variables environnementales et les mécanismes moléculaires mis en jeu dans la quiescence de cette espèce et dans une espèce éloignée, Clavelina lepadiformisColonial tunicates can generate a new adult body by asexual reproduction and whole body regeneration, two forms of non-embryonic development (NED). Different modes of NED are defined depending on the nature of the organogenetic tissues. Interestingly, this capacity is scattered across the sub-phylum, with species able of NED (colonial) closely related to species where regenerative capabilities are absent or reduced (solitary). This suggests that NED has been acquired or lost several times among the group. In recent phylogeny of family Styelidae, the colonial species Polyandrocarpa zorritensis seems to have acquired independently the capability of NED. During my PhD, I characterized the NED in this species, identifying the stages of NED under laboratory conditions and the tissues/cells involved. By histological and ultrastructural analyses, I highlighted the participation to NED of vascular epithelium and mesenchymal cells. This type of NED was undescribed before, and we decided to call it “vasal budding”. During the early stages of vasal budding I observed undifferentiated mesenchymal cells cluster and proliferate at the regenerative point; their distribution varies during vasal budding, increasing in the developing areas. I described the mesenchymal cells, identifying in the proliferating cells an undifferentiated morphotype, the hemoblasts, known as putative stem cells in other colonial ascidian. In addition, I defined the presence of a dormant stage, the spherule, in the life cycle of P. zorritensis and I characterized the environmental variable and the molecular mechanisms involved in dormancy in this species and in a distantly related species, Clavelina lepadiformis
4
Messineo, Stefania. « Development of a gene targeting strategy (Recombinase-Mediated CAssette Exchange) to generate cellular models of MYH9-related disease ». Doctoral thesis, Università degli studi di Trieste, 2011. http://hdl.handle.net/10077/4603.
Texte intégralRésumé :
2009/2010La malattia MYH9-correlata (MYH9-RD) è una malattia autosomica dominante, caratterizzata da trombocitopenia congenita con piastrine di grandi dimensioni, aggregati nei neutrofili, sordità progressiva, cataratta e nefropatia. La MYH9-RD è causata da mutazioni nel gene MYH9 che codifica per la catena pesante della miosina non muscolare di classe II (miosina-9). I meccanismi patogenetici che causano questa malattia non sono ancora stati chiaramente identificati e il loro studio è complicato dalla mancanza di adeguati modelli cellulari e animali. Lo scopo di questo progetto è stato di generare un modello in vitro per studiare la funzione della miosina-9 e il ruolo di due mutazioni che incorrono nel gene MYH9: la R702C e la R1933X, che correlano rispettivamente con un fenotipo grave e lieve. Per questo motivo abbiamo deciso di manipolare le cellule staminali embrionali murine (ES), che sono pluripotenti e possono essere differenziate in diversi linee cellulari, compresa la linea megacariocitica. Per ingegnerizzare queste cellule ad alta efficienza abbiamo messo a punto una strategia nota come "scambio di cassette mediato da ricombinasi" (RMCE). Dopo l'integrazione di una cassetta fiancheggiata da siti FRT (sequenze di riconoscimento per l'enzima flippasi), il sistema ci ha permesso di scambiare diverse sequenze di DNA in presenza dell'enzima flippasi. Quindi il primo esone codificante del gene Myh9 è stato distrutto dall'inserimento, mediante ricombinazione omologa, di una cassetta fiancheggiata da due siti FRT contenente il gene reporter Beta-galattosidasi. Successivamente abbiamo scambiato questa cassetta con altre tre contenenti il cDNA Myh9 murino wild-type e i due mutati, generando i cloni ES che esprimono queste sequenze esogene sotto il controllo del promotore Myh9 endogeno. La caratterizzazione a livello dell'RNA e delle proteine di questi cloni ci ha portato a stabilire che gli alleli mutati e wild-type sono espressi allo stesso livello, suggerendo che le manipolazioni genetiche non interferiscono con i corretti meccanismi fisiologici di trascrizione e traduzione del gene Myh9. Tuttavia, mediante Western Blot abbiamo mostrato che la proteina miosina-9 è espressa a livello inferiore nei cloni mutati rispetto ai wild-type. Le analisi di immunofluorescenza per indagare la presenza di aggregati di miosina-9, che sono sempre presenti nei neutrofili di pazienti, non hanno rilevato alcuna variazione nella distribuzione della miosina-9, fatta eccezione per un segnale di intensità minore. Questi risultati indicano che, nonostante l'espressione dell'allele ingegnerizzato sia normale, la proteina mutata sembra essere degradata, almeno nelle cellule ES murine, determinando un effetto di aploinsufficienza delle mutazioni R702C e R1933X. Per accertare la loro pluripotenza, abbiamo differenziato dei cloni ES in corpi embrioidi e cardiomiociti, senza rivelare alcuna differenza tra i cloni mutanti e i wild-type. Dal momento che una caratteristica congenita dei pazienti MYH9-RD è la macrotrombocitopenia, abbiamo sviluppato un protocollo per differenziare i cloni mutati ES in megacariociti per indagare come le mutazioni in MYH9 portino a una impropria produzione di piastrine. In conclusione, per studiare la MYH9-RD abbiamo sviluppato una strategia che ci ha permesso di esprimere sequenze di interesse in cellule ES di topo sotto il controllo del promotore Myh9 endogeno. La differenziazione in vitro di queste cellule ci permetterà di studiare l'effetto delle mutazioni nel corso della megacariocitopoiesi. Inoltre, poiché le cellule ES possono anche essere usate per generare modelli animali, questa strategia ci permetterà di testare diverse ipotesi patogenetiche in vitro, prima di passare a studi in vivo.
XXIII Ciclo
1982
5
Yunusov, Dinar. « Characterization of HIPSTR highlights the heterogeneous expression pattern of lncRNAs in human embryos and stable cell lines ». Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-22082016-083421/.
Texte intégralRésumé :
There is a growing appreciation that eukaryotic genomes are transcribed into numerous, previously undetected - and thus uncharacterized regulatory long non-coding RNAs (lncRNAs). Recent studies are primarily focused on lncRNAs transcribed from intergenic regions and enhancers, leaving antisense lncRNAs the least studied group of lncRNAs. At the same time, antisense transcription occurs in up to 74 % of human gene loci, frequently - from the opposite strand of genes encoding proteins involved in regulation of transcription. Here, we identified HIPSTAR (Heterogeneously expressed from the Intronic Plus Strand of the TFAP2A-locus RNA), a novel conserved lncRNA that is transcribed antisense to the TFAP2A gene. Unlike previously reported antisense lncRNAs, HIPSTR expression does not correlate with the expression of its antisense counterpart. Although HIPSTAR and TFAP2A are co-expressed in in vitro derived neural crest and trophoblast cells, only HIPSTAR and not TFAP2A is specifically expressed in a subset of cells within 8-cell- and morula-stage human embryos. We show that, similar to HIPSTAR, in the individual cells of developing human embryos or of stable cell lines the expression of lncRNAs is more highly heterogeneous than the expression of mRNAs. Finally, we demonstrate that HIPSTAR depletion in HEK293 and H1BP, a human embryonic stem cell line, predominantly affects the expression levels of genes involved in early organismal development and cell differentiation. Together, we show that expression of HIPSTAR and hundreds other lncRNAs is highly heterogeneous in human embryos and cell lines. We use HIPSTAR to exemplify the functional relevance of lncRNAs with heterogeneous and developmental stage-specific expression patterns.Tem sido cada vez mais reconhecido que a transcrição dos genomas eucarióticos produz múltiplos transcritos novos, anteriormente não detectados e ainda não caracterizados, sendo que a maioria é constituida de RNAs não-codificantes longos (lncRNAs) regulatórios. Estudos recentes estão focados principalmente nos lncRNAs transcritos de regiões intergênicas e enhancers; assim, o grupo dos lncRNAs antisenso permanece o menos estudado de todos. Ao mesmo tempo, a transcrição antisenso ocorre em até 74% dos loci de genes humanos, frequentemente - a partir da fita oposta de genes que codificam proteínas envolvidas na regulação da transcrição. No presente trabalho, nós identificamos HIPSTR (Heterogeneously expressed from the Intronic Plus Strand of the TFAP2A-locus RNA), um lncRNA novo conservado que é transcrito a partir da fita antisenso do gene TFAP2A. Ao contrário do anteriormente relatado para os lncRNAs antisenso, a expressão de HIPSTR não está correlacionada com a expressão do gene da fita oposta. HIPSTR e TFAP2A são co-expressos em células da crista neural e em trofoblastos derivadas in vitro, mas somente HIPSTR e não TFAP2A está especificamente expresso num subconjunto de células de embriões humanos nos estágios de 8-células e mórula. Mostramos que, semelhante a HIPSTR, a expressão de lncRNAs é mais altamente heterogênea que a expressão de mRNAs em células individuais de embriões humanos em desenvolvimento ou em linhagens estáveis de células. Finalmente, nós demonstramos que a depleção de HIPSTAR em células HEK293 e H1BP, uma linhagem de células tronco embrionárias humanas, afeta predominantemente os níveis de genes envolvidos no início do desenvolvimento do organismo e na diferenciação de células. No conjunto, nós mostramos que a expressão de HIPSTR e de centenas de outros lncRNAs é altamente heterogênea em embriões humanos e linhagens celulares. Usamos HIPSTR para exemplificar a relevância funcional de lncRNAs com padrões de expressão heterogêneos e estágio-de-desenvolvimento específicos.
6
Mokrani, Sofiane. « Maintenance de la stabilité chromosomique des cellules souches neurales murines au cours du développement et après un stress génotoxique aiguë ou chronique Impaired brain development and behavior of Xlf null mice linked to chromosome instability-induced premature neurogenesis Higher Chromosome Stability in Mouse Embryonic Neural Stem and Progenitor Cells than in Fibroblasts in Response to Acute or Chronic Genotoxic Stress ». Thesis, Institut polytechnique de Paris, 2019. http://www.theses.fr/2019IPPAX010.
Texte intégralRésumé :
Une exposition prénatale aux radiations ionisantes est associée au développement de pathologies neurodéveloppementales liées à l’induction de dommages à l’ADN dans les cellules souches et progéniteurs neuraux (CSPN). Ainsi, la stabilité génétique des CSPN est cruciale pour le développement et l’homéostasie du cerveau. Cependant, des altérations génomiques au niveau des CSPN au cours du développement pourraient promouvoir la diversité neuronale. XLF est un composant de la voie de réparation d’ADN par NHEJ (pour Non-Homologous End-Joining). Nous avons montré une augmentation de l’instabilité des CSPN dans le cerveau embryonnaire des souris Xlf-/- qui pourrait perturber la neurogenèse au cours du développement, et ainsi être responsable d’altérations comportementales identifiées chez ces souris à l’âge adulte. A l’aide d’approches cytogénétiques, nous avons comparés la stabilité chromosomique des CSPN et des fibroblastes embryonnaires murins (MEF) exposés à un stress génotoxique aigue (irradiation γ) ou chronique (incorporation de thymidine tritiée dans l’ADN). Nos résultats démontrent que les CSPN maintiennent leur intégrité génétique de façon plus efficace que les MEF. En effet, les CSPN semblent avoir de meilleures capacités de réparation des dommages à l’ADN que les MEF, ce qui leur permet de développer une réponse adaptative à un stress génotoxique chronique. Cette réponse adaptative implique XLF et agit conjointement avec les points de contrôle du cycle cellulaire et l'apoptose pour préserver la stabilité du génome et éliminer les cellules endommagées. L’ensemble de nos résultats apporte la démonstration d’une réponse robuste aux dommages de l'ADN dans les CSPN et souligne l'importance de XLF lors du développement du cerveauPrenatal exposure to ionizing radiation has been associated with many neurodevelopmental disorders due to the DNA damage induced in neural stem and progenitors cells (NSPC). Thus, genetic stability of NSPC is crucial for brain development and homeostasis. Nevertheless, genomic alterations occurring during development in NSPC may have a potential impact on the physiological neuronal diversity. XLF is a component of the NHEJ (Non-Homologous End-Joining) repair pathway. Here, we show that NSPC from Xlf-/- embryos exhibit increased chromosome instability, leading to premature neurogenesis and consequently neurobehavioral disorders. Using cytogenetic approaches, we compared the chromosome stability of mouse embryonic NSPC and fibroblasts (MEF) exposed to acute (γ-irradiation) or chronic (incorporation of tritiated thymidine into DNA) genotoxic stress. Our results demonstrate the higher capacity of NSPC as compared to MEF to maintain their genomic integrity. We evidenced that NSPC have more efficient DNA repair activity than MEF, allowing them to develop an adaptive response to chronic genotoxic stress. This adaptive response involves XLF and acts together with apoptosis and cell cycle checkpoints to preserve the stability of the genome and to eliminate damaged cells. Altogether, our results provide new insights into the robust DNA damage response in NSPC and highlight the importance of Xlf during brain development
7
Bing, Xin Y. « Mechanistic Basis for Control of Early Embryonic Development by a 5’ tRNA Fragment ». eScholarship@UMMS, 2019. https://escholarship.umassmed.edu/gsbs_diss/1035.
Texte intégralRésumé :
Ancestral environmental conditions can instruct offspring development, although the mechanism(s) underlying such transgenerational epigenetic inheritance is unclear. In murine models focused on paternal dietary effects, we and others have identified tRNA fragments (tRFs) in mature sperm as potential carriers of epigenetic information. In our search for molecular targets of specific tRFs, we observed that altering the level of 5’-tRF Glycine-GCC (tRF-GG) in mouse embryonic stem cells (mESCs) and preimplantation embryos modulates the expression of the endogenous retrovirus MERV-L and genes regulated by MERV-L. Intriguingly, transient derepression of MERV-L is associated with totipotency of two-cell stage embryos and a subset of two-cell-like mESCs.
Here, I reveal the mechanistic basis for tRF-GG regulation of MERV-L. I show that tRF-GG supports the production of numerous small nuclear RNAs associated with the Cajal body, in mouse and human embryonic stem cells. In particular, tRF-GG modulates the levels of U7 snRNA to ensure an adequate supply of histone proteins. This in turn safeguards heterochromatin-mediated transcriptional repression of MERV-L elements. Importantly, tRF-GG effects on histone mRNA levels, activity of a histone 3’UTR reporter, and expression of MERV-L associated transcripts can all be suppressed by appropriate manipulation of U7 RNA levels. I also show that hnRNPF and H bind directly to tRF-GG, and display a stark overlap of in vivo functions to tRF-GG. Together, this data uncovers a conserved mechanism for a 5’ tRNA fragment in the fine-tuning of a regulatory cascade to modulate global chromatin organization during pre-implantation development.
8
Lefebvre, Fabio Alexis. « Approches de fractionnement biochimique couplé à la transcriptomique dans l’étude systématique de la localisation subcellulaire et extracellulaire des ARNs ». Thèse, 2018. http://hdl.handle.net/1866/21186.
Texte intégralLivres sur le sujet "Non-Embryonic development"
1
Coulson, Graeme, et Mark Eldridge, dir. Macropods. CSIRO Publishing, 2010. http://dx.doi.org/10.1071/9780643098183.
Texte intégralRésumé :
This book covers the proceedings of a major 2006 symposium on macropods that brought together the many recent advances in the biology of this diverse group of marsupials, including research on some of the much neglected macropods such as
the antilopine wallaroo, the swamp wallaby and tree-kangaroos.
More than 80 authors have contributed 32 chapters, which are grouped into four themes: genetics, reproduction and development; morphology and physiology; ecology; and management.
The book examines such topics as embryonic development, immune function, molar progression and mesial drift, locomotory energetics, non-shivering thermogenesis, mycophagy, habitat preferences, population dynamics, juvenile mortality in drought,
harvesting, overabundant species, road-kills, fertility control, threatened species, cross-fostering, translocation and reintroduction. It also highlights the application of new techniques, from genomics to GIS.
Macropods is an important reference for academics and students, researchers in molecular and ecological sciences, wildlife and park managers, and naturalists.
2
Ruiz-Villalba, Adrián, Nikolaos Frangogiannis et José Maria Pérez-Pomares. Origin and diversity of cardiac fibroblasts : developmental substrates of adult cardiac fibrosis. Sous la direction de José Maria Pérez-Pomares, Robert G. Kelly, Maurice van den Hoff, José Luis de la Pompa, David Sedmera, Cristina Basso et Deborah Henderson. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198757269.003.0012.
Texte intégralRésumé :
Cardiac connective tissues are primarily formed by cardiac fibroblasts (CF) of diverse embryonic origins. Whereas CF specific roles in cardiac morphogenesis remain under-researched, their involvement in adult cardiac fibrosis is clinically relevant. Cardiac fibrosis is a common element of several chronic cardiac conditions characterized by the loss of ventricular wall mechanical function, ultimately driving to heart failure. In the ischaemic heart early reparative fibrosis evidences the very restricted regenerative potential of the myocardium. In non-ischaemic diseases fibrosis is activated by unknown signals. We summarize current knowledge on the origin of CFs and their developmental roles, and discuss the differential disease-dependent response of different CF subpopulations to various pathological stimuli. We also describe the characteristic cell-cell and cell-matrix interactions that determine the fibrotic remodelling of the myocardium. We analyse experimental models for the study of cardiac fibrosis, and suggest future directions in the search for new markers and therapeutic targets.
Chapitres de livres sur le sujet "Non-Embryonic development"
1
Fu, Qiang, Chuan-Jiang Liu, Zhen-Sheng Zhai, Xu Zhang, Tao Qin et Hong-Wei Zhang. « Single-Cell Non-coding RNA in Embryonic Development ». Dans Single Cell Biomedicine, 19–32. Singapore : Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-0502-3_3.
Texte intégral
2
Tobita, Kimimasa, Jason B. Garrison et Bradley B. Keller. « Differential Effects of Cyclic Stretch on Embryonic Ventricular Cardiomyocyte and Non-Cardiomyocyte Orientation ». Dans Cardiovascular Development and Congenital Malformations, 177–79. Malden, Massachusetts, USA : Blackwell Publishing Ltd, 2007. http://dx.doi.org/10.1002/9780470988664.ch44.
Texte intégral
3
Latinkic, Branko V. « CCN FAMILY IN EMBRYONIC DEVELOPMENT (NON-MAMMALIAN MODELS) ». Dans CCN Proteins, 153–65. PUBLISHED BY IMPERIAL COLLEGE PRESS AND DISTRIBUTED BY WORLD SCIENTIFIC PUBLISHING CO., 2005. http://dx.doi.org/10.1142/9781860946899_0008.
Texte intégral
4
Deeming, D. C. « Embryonic development and utilisation of egg components ». Dans Avian Incubation, 43–53. Oxford University PressOxford, 2001. http://dx.doi.org/10.1093/oso/9780198508106.003.0004.
Texte intégralRésumé :
Abstract Development of bird embryos of domestic species is well reported but given the diversity of bird species there are relatively few descriptive reports of development in non-commercial species (Ricklefs and Starck 1998). Patterns of embryonic development in different species have been found to be largely similar and the domestic fowl (Gallus gallus) embryo has proved to be a useful general model for avian development. In this chapter space prevents an in-depth description of the pattern of embryonic development in any particular species and this would be largely redundant given previous publications (Romanoff 1960; Freeman and Vince 1974; Bellairs and Osmond 1998; Ricklefs and Starck 1998). Rather, an attempt is made to provide a basic description of embryonic development through to hatching, with emphasis on the changes in extra-embryonic environment within the shell. Freeman and Vince (1974) describe behavioural aspects of development and interactions between the developing embryo and the incubating adult as described in Chapter 7.
5
Topilko, P., et D. Meijer. « Transcription Factors that Control Schwann Cell Development and myelination ». Dans Glial Cell Development basic principles and clinical relevance second edition, 223–44. Oxford University PressOxford, 2001. http://dx.doi.org/10.1093/oso/9780198524786.003.0011.
Texte intégralRésumé :
Abstract It is now well established that the continuous dialog between neuron and Schwann cell underlies the development, maintenance and regeneration of peripheral nerves (see Chapters 1 and 15). Most of the Schwann cells within the developing nerve, as well as the other glial cell types in the peripheral nervous system (PNS), such as the satellite cells, the teloglia and enteric glial cells, derive from the neural crest (Le Douarin et al., 1991; Anderson, 1997). Immature Schwann cells proliferate, migrate, invade, bundle and sort the axonal fibers of the embryonic nerve. This process continues until the Schwann cells ensheath individual larger caliber axons or multiple lower caliber axons. Schwann cells then cease to proliferate and commence to myelinate the larger axons, while the non-myelin-forming Schwann cells further ensheath multiple smaller axons resulting in the mature Schwann cell phenotypes observed in the nerves of adult animals (Webster, 1993). The differentiation of the two types of Schwann cells takes place during the first weeks of postnatal life in rodents. A number of distinct steps in the generation of mature Schwann cells can be distinguished. (i) Pluripotent neural crest stem cells must acquire a glial cell fate during entry into, or within the embryonic nerve. (ii) This glial cell population expands and invades the nerve bundle. (iii) Immature cells will adopt a promyelin-forming or a pro-nonmyelin-forming configuration with axons and cease to proliferate.
6
Zimmer, Julia, Elisa Degenkolbe, Britt Wildemann et Petra Seemann. « BMP Signaling in Regenerative Medicine ». Dans Medical Advancements in Aging and Regenerative Technologies, 1–30. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2506-8.ch001.
Texte intégralRésumé :
More than 40 years after the discovery of Bone Morphogenetic Proteins (BMPs) as bone inducers, a whole protein family of growth factors connected to a wide variety of functions in embryonic development, homeostasis, and regeneration has been characterized. Today, BMP2 and BMP7 are already used in the clinic to promote vertebral fusions and restoration of non-union fractures. Besides describing present clinical applications, the authors review ongoing trials highlighting the future possibilities of BMPs in medicine. Apparently, the physiological roles of BMPs have expanded their range from bone growth induction and connective tissue regeneration to cancer diagnosis/treatment and cardiovascular disease prevention.
7
Granderath, S., et C. Klämbt. « Genetic analysis of gliogenesis in Drosophila ». Dans Glial Cell Development basic principles and clinical relevance second edition, 244–62. Oxford University PressOxford, 2001. http://dx.doi.org/10.1093/oso/9780198524786.003.0012.
Texte intégralRésumé :
Abstract Neural circuits are made up of interconnecting neurons, and processing of information can be explained purely on the basis of neuronal properties. However, in all complex nervous systems, non-neuronal cells—the glial cells—also have to be considered. During the evolution of metazoans, the number of glial cells increases in relation to the complexity of the nervous system. In the vertebrate central nervous system (CNS), glial cells even outnumber neuronal cells by a ratio of 10 to 1. In contrast, only 10% of the cells of the Drosophila nervous system are glia. Glial cells are found in the CNS as well as in the peripheral nervous system (PNS). In the following, we will focus on the development of the embryonic CNS glial cells of Drosophila, the determination and differentiation of which is best understood. Detailed descriptions of peripheral glial cells, and glial cells found in the adult nervous system, have been published (Campos-Ortega and Hartenstein, 1985; Winberg et al., 1992; Giangrande et al., 1993; Giangrande, 1995; Tix et al., 1997; Hartenstein et al.,1998).
8
Harvey Pough, F., William E. Bemis, Betty Mcguire et Christine M. Janis. « What Is a Vertebrate ? » Dans Vertebrate Life. Oxford University Press, 2022. http://dx.doi.org/10.1093/hesc/9780197558621.003.0002.
Texte intégralRésumé :
This chapter explains that vertebrates belong to the phylum Chordata, which along with the echinoderms and the hemichordates comprise the Deuterostomia. Deuterostomes and protostomes are the subdivisions of the more complex animals with bilateral symmetry and bodies that develop from three layers of tissue. The chapter looks at non-chordate deuterostomes, which are all small marine animals that are united by the presence of pharyngeal slits at some stage of their lives. The main characteristic of all chordates is the notochord, which is a dorsal stiffening rod to which muscles attach and are seen at some point of development in all chordates. The chapter shows that the notochord is a transient structure in most vertebrates. This is replaced during embryonic development by the vertebral column.
9
Becker, David, et Colin Green. « Gap junction-mediated interactions between cells ». Dans Cell–Cell Interactions, 47–70. Oxford University PressOxford, 2001. http://dx.doi.org/10.1093/oso/9780199638642.003.0003.
Texte intégralRésumé :
Abstract Gap junction channels are expressed in almost all types of cell. Their roles are diverse and are crucial for normal embryonic development and the functioning of adult organs. Point mutations, in a growing number of members of the gap junction family, appear to underlie several human diseases including profound non-syndromic deafness, heart disease, peripheral nerve myopathy, skin disorders, and cataract promotion. This has led to a rapid increase in the number of researchers investigating gap junctional communication in these disease conditions. In order to study gap junctional interactions between cells, there are three basic approaches which, when integrated, provide a rounded picture of communication in any particular system.
10
Luyten, Frank P. « Mesenchymal Stem Cells In Arthritis ». Dans Rheumatoid Arthritis, 551–59. Oxford University PressOxford, 2006. http://dx.doi.org/10.1093/oso/9780198566304.003.0043.
Texte intégralRésumé :
Abstract Recent advances in our understanding of the biology of stem cells have attracted the attention of the biomedical community1–4. Basic scientists and clinicians are moving in concert, trying to bridge the gap from ‘bench to bedside’, and to unravel the biology of stem cell populations in development, growth, homeostasis, and disease. Adult stem cells are found in most adult tissues. Adult stem cells, hematopoietic and non-hematopoietic, are more restricted than embryonic stem cells, although recent findings have revealed the existence, at least in vitro, of adult marrow-derived, pluripotent stem cells (MAPCs) with a differentiation potential close to embryonic stem cells . However, more critical studies directed toward hematopoietic stem cells have disputed the concept of stem cell plasticity, suggesting that experimental artifact or somatic cell fusion may account for some reported observations of plasticity. Animal and human models with appropriate cell tracking and in vivoimaging technologies to explore the biology and therapeutic potential of human stem cells will be vital to advance the field over the coming years . Regardless, cumulative data suggest that precursor cells, residing in ‘niches’ or recruited from circulating stem cells, can participate in tissue homeostasis and repair, but also potentially contribute to disease processes.
Actes de conférences sur le sujet "Non-Embryonic development"
1
Moran, Emma C., Pedro M. Baptista, Kenichiro Nishii, David Wasnick, Shay Soker et Jessica L. Sparks. « Expression of Primary Cilia on Liver Stem and Progenitor Cells : Potential Role for Mechanosensing in Liver Development ». Dans ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14122.
Texte intégralRésumé :
The primary cilium is a non-motile organelle that projects out from the plasma membrane of many cell types in the body. It consists of an axoneme with microtubules arranged in a 9+0 arrangement that extends from the mother centriole contained within the basal body. Once thought to be a non-essential organelle, it is now known that primary cilia have an important role in embryonic and post-natal development, as well as maintenance of adult tissues. Mutations affecting primary ciliary development result in a class of serious diseases known as ciliopathies [1, 2]. Recent research suggests that the primary cilia/ centrosomes might play a role in embryonic stem cell differentiation through cell cycle regulation and their association with the Hedgehog signaling pathway [3, 4].
2
Tan, Hao, Ya Su, Liya Wei, X. Steve Yao, Tongtong Mai et Xu Li. « Non-invasive 3D real time observation of physiological traits during the embryonic development of insects ». Dans Optics in Health Care and Biomedical Optics IX, sous la direction de Qingming Luo, Xingde Li, Yuguo Tang, Ying Gu et Dan Zhu. SPIE, 2019. http://dx.doi.org/10.1117/12.2537479.
Texte intégral
3
Bercha, Frank, Richard Prentki et Caryn Smith. « Prediction of Oil Spill Occurrence Probabilities in the Alaskan Beaufort and Chukchi Seas OCS ». Dans SNAME 8th International Conference and Exhibition on Performance of Ships and Structures in Ice. SNAME, 2008. http://dx.doi.org/10.5957/icetech-2008-118.
Texte intégralRésumé :
Probabilistic estimates of oil spill occurrences are used in the development of environment impact assessments for possible future developments in the US Chukchi and Beaufort Seas. Due to the embryonic state of offshore oil development in this region, it was not possible to base these oil spill probability estimates on empirical data. Rather, statistically significant non-Arctic empirical data from the US Gulf of Mexico and world-wide sources, together with their variance, were used as a starting point. Next, both the historical non-Arctic frequency distributions and spill causal distributions were modified to reflect specific effects of the Arctic setting, and the resultant fault tree model was evaluated using Monte Carlo simulation to adequately characterize uncertainties treated as probability distribution inputs to the fault tree. This paper summarizes the methodology and gives results of its application to the estimation of oil spill probabilities and their characteristics for the Chukchi and Beaufort Seas region for typical future offshore development scenarios.
4
Bercha, Frank G., Richard Prentki, Caryn Smith et Milan Cerovsek. « Prediction of Oil Spill Occurrence Probabilities in the Alaskan OCS ». Dans SNAME 7th International Conference and Exhibition on Performance of Ships and Structures in Ice. SNAME, 2006. http://dx.doi.org/10.5957/icetech-2006-115.
Texte intégralRésumé :
Probabilistic estimates of oil spill occurrences are required for the development of environment impact assessments for possible future developments in the US Beaufort Sea. Due to the embryonic state of offshore oil development in this region, it was not possible to base these oil spill probability estimates on empirical data. Rather, statistically significant non-Arctic empirical data, together with their variance, was used as a starting point. Next, both the frequency distributions and spill causal distributions were modified to reflect specific effects of the Arctic setting and the resultant fault tree model was evaluated using Monte Carlo simulation to adequately characterize the combinations of probability distribution inputs to the fault tree. This paper summarizes the methodology and gives results of its application to the prediction of oil spill probabilities and their characteristics for the Beaufort Sea region for typical future offshore development scenarios.
5
Oungoulian, Sevan R., Kelvin Chan, Jason Barritt, Casey A. McDonald, Alan B. Copperman, David Elad et Gerard A. Ateshian. « Influence of Zona Pellucida Area Expansion Stiffness on the Passive Response of Oocytes to Osmotic Loading ». Dans ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53826.
Texte intégralRésumé :
The zona pellucida (ZP) is a thick glycoprotein shell surrounding the mammalian egg cell (oocyte) that regulates spermatozoa access during fertilization and protects the zygote during early embryonic development [1]. Hardening of the zona pellucida over the cell fertilization cycle is a well-recognized phenomenon and has been investigated using contact methods to measure shear and bending elasticity from indentation and micropipette aspiration [2, 3]. However, the area elasticity of the ZP, which provides resistance to cell swelling under variable osmotic environments, has not yet been reported. A recently devised theoretical model [4] suggests that the ZP area expansion modulus may be determined through non-contact hypo-osmotic loading of the oocyte. If successful, this method may be suited for implementation by practicing fertility health professionals during routine manipulation.
6
Ataei, Abdol Hossain, et Figen Kırkpınar. « Application of In-Ovo Injection of Some Substances for Manipulation of Sex and Improving Performance in Chicken ». Dans International Students Science Congress. Izmir International Guest Student Association, 2021. http://dx.doi.org/10.52460/issc.2021.006.
Texte intégralRésumé :
In intensive production, freshly hatched cockerels are culled in the layer hatchery (7 billion males each year), On the other hand, for meat production rearing female birds has not economic benefits because of male broiler chicks have a faster growth rate and better feed efficiency than females. In this regards several methods are being developed for sex determination in the chick embryo during the incubation period. But these methods need to be rapid, cost-efficient, and suitable practical for commercial use. Additionally, sex determination should be done before pain perception has evolved in chick embryos. Biotechnology by in ovo technique to sex determination of between male and female chicks or sex reversal could improve production and eliminate ethical dilemmas for poultry industries. In birds, the differentiation of embryonic gonads is not determined by genetic gender with the certainty that occurs in mammals and can be affected by early treatment with a steroid hormone. During the development of the chick embryo, the genotype of the zygote determines the nature of the gonads, which then caused male or female phenotype. The differentiation of gonads during the period called the "critical period of sexual differentiation" is accompanied by the beginning of secretion of sexual hormones. Namely, any change in the concentration of steroid hormones during the critical period affects the structure of the gonads. Many synthetic anti-aromatases such as federazole and non-synthetic in plants, mushrooms, and fruits containing natural flavonoids have been used in the experiments in ovo injection of anti-aromatase had no negative effect on the growth performance of sexual reversal female chickens. In conclusion, administration of an aromatase inhibitor causes testicular growth in the genetic female gender, and estrogen administration leads to the production of the left ovotestis in the genetic male gender. Therefore, in the early stages of embryonic development, sexual differentiation can be affected by changing the ratio of sexual hormones. In this review, effects of some substances applied by in ovo injection technique on sex reversal and performance in chicks.
7
Bercha, Frank G. « Arctic and Northern Offshore Oil Spill Probabilities ». Dans SNAME 9th International Conference and Exhibition on Performance of Ships and Structures in Ice. SNAME, 2010. http://dx.doi.org/10.5957/icetech-2010-187.
Texte intégralRésumé :
Current catastrophic consequences of the Gulf of Mexico blowout have refocused interest on the probabilities of such events in both temperate and northern regions. This paper reviews some of the early studies on oil spill probabilities with emphasis on oil blowouts, and details more recent studies carried out specifically for the Alaskan OCS. Due to the embryonic state of offshore oil development in arctic regions, which has been the case since 1976 to the present, it is not possible to base oil spill probability estimates on empirical data. The early studies relied on a detailed fault tree analysis dealing with the operations as systems without history. More recent studies in northern but not arctic operations use world wide data as a starting point. In the recent and current Alaskan OCS studies, statistically significant non-Arctic empirical data from the US Gulf of Mexico and world-wide sources, together with their variance, were used as a starting point. Next, both the historical non-Arctic frequency distributions and spill causal distributions were modified to reflect specific effects of the Arctic setting, and the resultant fault tree model was evaluated using Monte Carlo simulation to adequately characterize uncertainties treated as probability distribution inputs to the fault tree.
8
Orendain, Adam, Jose Carrasco, Eniko T. Enikov et Gholam Peyman. « Evaluation of Electro-Spun Tubular Scaffolds to Create an Anastomosis Using the CAM Assay ». Dans ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-64687.
Texte intégralRésumé :
Central retinal vein occlusion (CRVO) is a vascular disease characterized by thrombosis of the retinal veins that can eventually lead to ischemia. Ischemic CRVO can then cause macular degeneration and neovascular glaucoma causing partial to full blindness. In this study, we determined the feasibility of electrospinning tubular scaffolds for treating CRVO and vascular disease. Electrospinning was utilized to produce customizable scaffolds from nano-bers using collagen type I. Scaffolds were treated with glutaraldehyde, glycine, ethanol, UV light, and combinations of the treatments for the purpose cross-linking and to study their angiogenic effects. Structural properties of the scaffolds were analyzed with scanning electron micrsoscopy (SEM). Scaffolds were immobilized with human recombinant vascular endothelial growth factor (rhVEGF165) to investigate the drug-delivering abilities of the electrospun materials and as a method to produce vascularization. The chick chorioallantoic membrane (CAM) assay was used to examine the effects of VEGF immobilizations and to evaluate the feasibility of creating an anastomosis to treat CRVO. Collagen onplants (non-electrospun) and electrospun implants were made on day 10 of embryonic development. Findings show collagen loaded with rhVEGF165 had improved vasculature and pro-angiogenic properties. The present study suggests that collagen can immobilize and release growth factor, be electrospun to mimic the ultrastructure of native blood vessels, and holds promise for vascular tissue engineering.
9
Rugonyi, Sandra, et Kent Thornburg. « Modeling the Effect of Hemodynamics on Cardiac Growth During Embryonic Development ». Dans ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology. ASMEDC, 2010. http://dx.doi.org/10.1115/nemb2010-13171.
Texte intégralRésumé :
Congenital heart disease (CHD) affects about 1% of newborn babies in the US, and is the leading cause of non-infectious death in children. Abnormal blood flow dynamics during early development can lead to CHD. Although the effect of hemodynamic conditions on cardiac development — even under normal conditions — has been widely accepted, the mechanisms by which blood flow influences cardiac cell responses are only starting to emerge. Mathematical models of cardiac growth could then help elucidate key aspects of cardiac development.
10
Liu, Aiping, Ruikang Wang, Kent L. Thornburg et Sandra Rugonyi. « Efficient Synchronization and Reconstruction of 4D Non-Gated Cardiac Images of Chick Embryos Obtained From Optical Coherence Tomography ». Dans ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-206383.
Texte intégralRésumé :
Four-dimensional (4D) imaging with optical coherence tomography (OCT) — a high-resolution, noninvasive tomographic imaging technique — applied to cardiac development can be used to study the interaction of cardiac morphology and function in vivo. However, to image the fast beating embryonic heart, the biggest challenge confronted by current OCT systems is the slow rate of 3D volume image data acquisition.
Rapports d'organisations sur le sujet "Non-Embryonic development"
1
Browdy, Craig, et 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, août 2002. http://dx.doi.org/10.32747/2002.7695849.bard.
Texte intégralRésumé :
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.
2
Uni, Zehava, et Peter Ferket. Enhancement of development of broilers and poults by in ovo feeding. United States Department of Agriculture, mai 2006. http://dx.doi.org/10.32747/2006.7695878.bard.
Texte intégralRésumé :
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.
3
Spencer, Thomas E., Elisha Gootwine, Arieh Gertler et Fuller W. Bazer. Placental lactogen enhances production efficiency in sheep. United States Department of Agriculture, décembre 2005. http://dx.doi.org/10.32747/2005.7586543.bard.
Texte intégralRésumé :
The key objectives of this BARD project were to: (1) study long-term effects of immunization of prepubertal ewes against recombinant ovine placental lactogen (roPL) on subsequent birth weights of their lambs and their milk production; (2) optimize the anti-roPL immunization protocol using adjuvant preparations acceptable to producers and regulatory agencies; and (3) determine the physiological mechanism(s) whereby immunization against oPL increases fetal growth and development and mammogenesis. These objectives were based on key findings from a previous BARD project that: (a) immunization of ewes against roPL increased lamb birth weight and ewe milk production during lactation; (b) roPL and recombinant ovine growth hormone (roGH) increased the proliferation and differentiated function of endometrial glands that, in turn, would enhance uterine secretions necessary for fetal and placental growth; and (c) exogenous roPL and roGH stimulated mammogenesis and milk production during lactation. The BARD projects address central problems in sheep production, including reproductive failure due to embryonic/fetal mortality, low birth weight of lambs especially in prolific breeds, and reduced milk yields which affect neonatal survival. The sheep placenta secretes both lactogenic (oPL) and somatogenic (oGH) hormones. The receptors for those hormones are present in the fetus and placenta as well as maternal uterus, and mammary gland. Our research has focused on determining the biological role of these placental hormones in development and differentiation of the uterus during gestation and the mammary gland during pregnancy and lactation. Studies conducted in the current BARD project indicated that the effects of anti-roPL immunization were variable in ewes and that commercially available and widely acceptable adjuvant preparations were not effective to produce high anti-roPL titers in pre-pubertal ewes. In the non-prolific Rambouillet ewe in Texas and in the Awassi and the Assaf in Israel, anti-roPL immunization increased lamb birth weight; however, the magnitude of this effect and the inherent variability precluded our ability to determine the physiological mechanism of how the immunization increases fetal growth. Collectively, our findings suggest that anti-roPL immunization is not currently feasible as an easy and efficacious tool for the producer to increase flock reproductive and production efficiency. The variability in response of individual ewes to anti-roPL immunization likely includes modifying the recombinant hormone and the type of adjuvant used for the immunization. In particular, the oPL may need to be modified to ensure maximum antigenicity in a broad range of breed types. Nonetheless, the investigators continue to collaborate on identifying fundamental mechanisms that can be improved by genetics or management to enhance the efficiency of uteroplacental function and, in turn, fetal growth and development. High prolificacy is a desirable trait in intensive sheep production systems. One of the main limitations of using prolific breeds of sheep is that increased litter size is associated with low birth weights and increased mortality of lambs. Further, low birth weight is associated with an increased propensity for adult diseases and decreased production efficiency. Indeed, our recent studies find that the birth weights of lambs born in large litters can be improved by both genetics and management. Future cooperative research will continue to focus on reproductive efficiency of sheep that have broader implications for improving production efficiency in all types of ruminant livestock.