Talk:Blastocyst Development - Revision history

Z8600021 at 07:48, 7 December 2021

2021-12-07T07:48:38Z

← Older revision		Revision as of 17:48, 7 December 2021
Line 1:		Line 1:
	{{Talk Page}}		{{Talk Page}}

			==2021==

			Human blastoids model blastocyst development and implantation

			Harunobu Kagawa # 1 , Alok Javali # 1 , Heidar Heidari Khoei # 1 , Theresa Maria Sommer 1 , Giovanni Sestini 1 , Maria Novatchkova 1 2 , Yvonne Scholte Op Reimer 1 , Gaël Castel 3 , Alexandre Bruneau 3 , Nina Maenhoudt 4 , Jenna Lammers 3 5 , Sophie Loubersac 3 5 , Thomas Freour 3 5 , Hugo Vankelecom 4 , Laurent David 3 6 , Nicolas Rivron 7
			Affiliations expand
			PMID: 34856602 DOI: 10.1038/s41586-021-04267-8
			Abstract

			One week after fertilization, human embryos implant into the uterus. This event requires that the embryo forms a blastocyst consisting of a sphere encircling a cavity lodging the embryo proper. Stem cells can form a blastocyst model, which we termed blastoid1. Here we show that naive human pluripotent stem cells (PXGL hPSCs)2 triply inhibited for the Hippo, TGF-β, and ERK pathways efficiently (>70%) form blastoids generating blastocyst-stage analogs of the 3 founding lineages (>97% trophectoderm, epiblast, and primitive endoderm) according to the sequence and timing of blastocyst development. Blastoids spontaneously form the first axis and we observe that the epiblast induces the maturation of the polar trophectoderm that consequently acquires the specific capacity to attach to hormonally-stimulated endometrial cells, as during implantation. Such a human blastoid is a faithful, scalable, and ethical model to explore human implantation and development3,4.

	==2019==		==2019==

Z8600021 at 02:34, 27 Haziran 2019

2019-06-27T02:34:40Z

← Older revision		Revision as of 12:34, 27 Haziran 2019
Line 2:		Line 2:

	==2019==		==2019==

			===Computational analysis of single-cell transcriptomics data elucidates the stabilization of Oct4 expression in the E3.25 mouse preimplantation embryo===
			Sci Rep. 2019 Jun 20;9(1):8930. doi: 10.1038/s41598-019-45438-y.

			Gerovska D1,2, Araúzo-Bravo MJ3,4,5,6.

			Our computational analysis focuses on the 32- to 64-cell mouse embryo transition, Embryonic day (E3.25), whose study in literature is concentrated mainly on the search for an early onset of the second cell-fate decision, the specification of the inner cell mass (ICM) to primitive endoderm (PE) and epiblast (EPI). We analysed single-cell (sc) microarray transcriptomics data from E3.25 using Hierarchical Optimal k-Means (HOkM) clustering, and identified two groups of ICM cells: a group of cells from embryos with less than 34 cells (E3.25-LNCs), and another group of cells from embryos with more than 33 cells (E3.25-HNCs), corresponding to two developmental stages. Although we found massive underlying heterogeneity in the ICM cells at E3.25-HNC with over 3,800 genes with transcriptomics bifurcation, many of which are PE and EPI markers, we showed that the E3.25-HNCs are neither PE nor EPI. Importantly, analysing the differently expressed genes between the E3.25-LNCs and E3.25-HNCs, we uncovered a non-autonomous mechanism, based on a minimal number of four inner-cell contacts in the ICM, which activates Oct4 in the preimplantation embryo. Oct4 is highly expressed but unstable at E3.25-LNC, and stabilizes at high level at E3.25-HNC, with Bsg highly expressed, and the chromatin remodelling program initialised to establish an early naïve pluripotent state. Our results indicate that the pluripotent state we found to exist in the ICM at E3.25-HNC is the in vivo counterpart of a new, very early pluripotent state. We compared the transcriptomics profile of this in vivo E3.25-HNC pluripotent state, together with the profiles of E3.25-LNC, E3.5 EPI and E4.5 EPI cells, with the profiles of all embryonic stem cells (ESCs) available in the GEO database from the same platform (over 600 microarrays). The shortest distance between the set of inner cells (E3.25, E3.5 and E4.5) and the ESCs is between the E3.25-HNC cells and 2i + LIF ESCs; thus, the developmental transition from 33 to 34 cells decreases dramatically the distance with the naïve ground state of the 2i + LIF ESCs. We validated the E3.25 events through analysis of scRNA-seq data from early and late 32-cell ICM cells.
			PMID: 31222057 DOI: 10.1038/s41598-019-45438-y


	===Physiological profile of undifferentiated bovine blastocyst-derived trophoblasts===		===Physiological profile of undifferentiated bovine blastocyst-derived trophoblasts===

Z8600021 at 08:47, 5 Mayıs 2019

2019-05-05T08:47:49Z

← Older revision		Revision as of 18:47, 5 Mayıs 2019
Line 1:		Line 1:
	{{Talk Page}}		{{Talk Page}}

			==2019==

	==~~10 Most Recent~~==		===Physiological profile of undifferentiated bovine blastocyst-derived trophoblasts===
	{{10 ~~Most Recent}}~~
	~~===~~Blastocyst~~===~~		Biol Open. 2019 May 1;8(5). pii: bio037937. doi: 10.1242/bio.037937.
	~~<pubmed limit=10>Blastocyst</pubmed>~~
			Pillai VV1, Siqueira LG2,3, Das M1, Kei TG1, Tu LN1, Herren AW4, Phinney BS4, Cheong SH5, Hansen PJ2, Selvaraj V6.

			Trophectoderm of blastocysts mediate early events in fetal-maternal communication, enabling implantation and establishment of a functional placenta. Inadequate or impaired developmental events linked to trophoblasts directly impact early embryo survival and successful implantation during a crucial period that corresponds with high incidence of pregnancy losses in dairy cows. As yet, the molecular basis of bovine trophectoderm development and signaling towards initiation of implantation remains poorly understood. In this study, we developed methods for culturing undifferentiated bovine blastocyst-derived trophoblasts and used both transcriptomics and proteomics in early colonies to categorize and elucidate their functional characteristics. A total of 9270 transcripts and 1418 proteins were identified and analyzed based on absolute abundance. We profiled an extensive list of growth factors, cytokines and other relevant factors that can effectively influence paracrine communication in the uterine microenvironment. Functional categorization and analysis revealed novel information on structural organization, extracellular matrix composition, cell junction and adhesion components, transcription networks, and metabolic preferences. Our data showcase the fundamental physiology of bovine trophectoderm and indicate hallmarks of the self-renewing undifferentiated state akin to trophoblast stem cells described in other species. Functional features uncovered are essential for understanding early events in bovine pregnancy towards initiation of implantation.

			© 2019. Published by The Company of Biologists Ltd.

			KEYWORDS:
			Blastocyst; Implantation; Placenta; Pregnancy; Stem cells; Trophoblast
			PMID: 30952696

	==2017==		==2017==

Z8600021 at 23:42, 6 Mayıs 2018

2018-05-06T23:42:26Z

← Older revision		Revision as of 09:42, 7 Mayıs 2018
Line 8:		Line 8:

	==2017==		==2017==
			===Mechanics of blastocyst morphogenesis===
			Biol Cell. 2017 Sep;109(9):323-338. doi: 10.1111/boc.201700029. Epub 2017 Aug 4.

			Maître JL1.

			Abstract
			During pre-implantation development, the mammalian zygote transforms into the blastocyst, the structure that will implant the embryo in the maternal uterus. Consisting of a squamous epithelium enveloping a fluid-filled cavity and the inner cell mass, the blastocyst is sculpted by a succession of morphogenetic events. These deformations result from the changes in the forces and mechanical properties of the tissue composing the embryo. Here, I review the recent studies, which, for the first time, informed us on the mechanics of blastocyst morphogenesis.
			KEYWORDS:
			Cell adhesion; Cytoskeleton; Development; Mammals
			PMID: 28681376 DOI: 10.1111/boc.201700029

	===Four simple rules that are sufficient to generate the mammalian blastocyst===		===Four simple rules that are sufficient to generate the mammalian blastocyst===

Z8600021 at 05:51, 9 August 2017

2017-08-09T05:51:10Z

← Older revision		Revision as of 15:51, 9 August 2017
Line 7:		Line 7:
	<pubmed limit=10>Blastocyst</pubmed>		<pubmed limit=10>Blastocyst</pubmed>

			==2017==

			===Four simple rules that are sufficient to generate the mammalian blastocyst===

			PLoS Biol. 2017 Jul 12;15(7):e2000737. doi: 10.1371/journal.pbio.2000737. eCollection 2017 Jul.

			Nissen SB1, Perera M2, Gonzalez JM3, Morgani SM2, Jensen MH1, Sneppen K4, Brickman JM1,2, Trusina A1.

			Abstract

			Early mammalian development is both highly regulative and self-organizing. It involves the interplay of cell position, predetermined gene regulatory networks, and environmental interactions to generate the physical arrangement of the blastocyst with precise timing. However, this process occurs in the absence of maternal information and in the presence of transcriptional stochasticity. How does the preimplantation embryo ensure robust, reproducible development in this context? It utilizes a versatile toolbox that includes complex intracellular networks coupled to cell-cell communication, segregation by differential adhesion, and apoptosis. Here, we ask whether a minimal set of developmental rules based on this toolbox is sufficient for successful blastocyst development, and to what extent these rules can explain mutant and experimental phenotypes. We implemented experimentally reported mechanisms for polarity, cell-cell signaling, adhesion, and apoptosis as a set of developmental rules in an agent-based in silico model of physically interacting cells. We find that this model quantitatively reproduces specific mutant phenotypes and provides an explanation for the emergence of heterogeneity without requiring any initial transcriptional variation. It also suggests that a fixed time point for the cells' competence of fibroblast growth factor (FGF)/extracellular signal-regulated kinase (ERK) sets an embryonic clock that enables certain scaling phenomena, a concept that we evaluate quantitatively by manipulating embryos in vitro. Based on these observations, we conclude that the minimal set of rules enables the embryo to experiment with stochastic gene expression and could provide the robustness necessary for the evolutionary diversification of the preimplantation gene regulatory network.
			PMID: 28700688 PMCID: PMC5507476 DOI: 10.1371/journal.pbio.2000737

	==2016==		==2016==

Z8600021 at 00:38, 20 August 2016

2016-08-20T00:38:32Z

← Older revision		Revision as of 10:38, 20 August 2016
Line 8:		Line 8:


	==~~2015~~==		==2016==

			===Asymmetric division of contractile domains couples cell positioning and fate specification===

			Maître JL, et al. Nature. 2016.

			Abstract
			During pre-implantation development, the mammalian embryo self-organizes into the blastocyst, which consists of an epithelial layer encapsulating the inner-cell mass (ICM) giving rise to all embryonic tissues. In mice, oriented cell division, apicobasal polarity and actomyosin contractility are thought to contribute to the formation of the ICM. However, how these processes work together remains unclear. Here we show that asymmetric segregation of the apical domain generates blastomeres with different contractilities, which triggers their sorting into inner and outer positions. Three-dimensional physical modelling of embryo morphogenesis reveals that cells internalize only when differences in surface contractility exceed a predictable threshold. We validate this prediction using biophysical measurements, and successfully redirect cell sorting within the developing blastocyst using maternal myosin (Myh9)-knockout chimaeric embryos. Finally, we find that loss of contractility causes blastomeres to show ICM-like markers, regardless of their position. In particular, contractility controls Yap subcellular localization, raising the possibility that mechanosensing occurs during blastocyst lineage specification. We conclude that contractility couples the positioning and fate specification of blastomeres. We propose that this ensures the robust self-organization of blastomeres into the blastocyst, which confers remarkable regulative capacities to mammalian embryos.

			PMID 27487217

	==2014==		==2014==

Z8600021 at 12:05, 3 March 2015

2015-03-03T12:05:55Z

← Older revision		Revision as of 22:05, 3 March 2015
Line 8:		Line 8:


			==2015==

			==2014==

			===Oct4 is required for lineage priming in the developing inner cell mass of the mouse blastocyst===

			Development. 2014 Mar;141(5):1001-10. doi: 10.1242/dev.096875. Epub 2014 Feb 6.

			Le Bin GC1, Muñoz-Descalzo S, Kurowski A, Leitch H, Lou X, Mansfield W, Etienne-Dumeau C, Grabole N, Mulas C, Niwa H, Hadjantonakis AK, Nichols J.

			Abstract

			The transcription factor Oct4 is required in vitro for establishment and maintenance of embryonic stem cells and for reprogramming somatic cells to pluripotency. In vivo, it prevents the ectopic differentiation of early embryos into trophoblast. Here, we further explore the role of Oct4 in blastocyst formation and specification of epiblast versus primitive endoderm lineages using conditional genetic deletion. Experiments involving mouse embryos deficient for both maternal and zygotic Oct4 suggest that it is dispensable for zygote formation, early cleavage and activation of Nanog expression. Nanog protein is significantly elevated in the presumptive inner cell mass of Oct4 null embryos, suggesting an unexpected role for Oct4 in attenuating the level of Nanog, which might be significant for priming differentiation during epiblast maturation. Induced deletion of Oct4 during the morula to blastocyst transition disrupts the ability of inner cell mass cells to adopt lineage-specific identity and acquire the molecular profile characteristic of either epiblast or primitive endoderm. Sox17, a marker of primitive endoderm, is not detected following prolonged culture of such embryos, but can be rescued by provision of exogenous FGF4. Interestingly, functional primitive endoderm can be rescued in Oct4-deficient embryos in embryonic stem cell complementation assays, but only if the host embryos are at the pre-blastocyst stage. We conclude that cell fate decisions within the inner cell mass are dependent upon Oct4 and that Oct4 is not cell-autonomously required for the differentiation of primitive endoderm derivatives, as long as an appropriate developmental environment is established.
			KEYWORDS:
			Blastocyst; Chimaera; Nanog; Oct4 (Pou5f1); Primitive endoderm; Sox17

			PMID 24504341

			http://dev.biologists.org/content/141/5/1001.full?sid=77cc8ffa-dfd4-4195-b2f4-4bb11fa084e4

	==2012==		==2012==

Z8600021: /* 2012 */

2012-10-25T01:33:18Z

2012

← Older revision		Revision as of 11:33, 25 October 2012
Line 11:		Line 11:

	==2012==		==2012==

			===Cross-Species Genome Wide Expression Analysis during Pluripotent Cell Determination in Mouse and Rat Preimplantation Embryos===

			PLoS One. 2012;7(10):e47107. doi: 10.1371/journal.pone.0047107. Epub 2012 Oct 15.

			Casanova EA, Okoniewski MJ, Cinelli P.
			Source
			Institute of Laboratory Animal Science, University of Zurich, Zurich, Switzerland.

			Abstract

			The transition between morula and blastocyst stage during preimplantation development represents the first differentiation event of embryogenesis. Morula cells undergo the first cellular specialization and produce two well-defined populations of cells, the trophoblast and the inner cell mass (ICM). Embryonic stem cells (ESCs) with unlimited self-renewal capacity are believed to represent the in vitro counterpart of the ICM. Both mouse and rat ESCs can be derived from the ICM cells, but their in vitro stability differs. In this study we performed a microarray analysis in which we compared the transcriptome of mouse and rat morula, blastocyst, and ICM. This cross-species comparison represents a good model for understanding the differences in derivation and cultivation of ESCs observed in the two species. In order to identify alternative regulation of important molecular mechanisms the investigation of differential gene expression between the two species was extended at the level of signaling pathways, gene families, and single selected genes of interest. Some of the genes differentially expressed between the two species are already known to be important factors in the maintenance of pluripotency in ESCs, like for example Sox2 or Stat3, or play a role in reprogramming somatic cells to pluripotency like c-Myc, Klf4 and p53 and therefore represent interesting candidates to further analyze in vitro in the rat ESCs. This is the first study investigating the gene expression changes during the transition from morula to blastocyst in the rat preimplantation development. Our data show that in the pluripotent pool of cells of the rat and mouse preimplantation embryo substantial differential regulation of genes is present, which might explain the difficulties observed for the derivation and culture of rat ESCs using mouse conditions.

			PMID 23077551


	Yamagata K, Iwamoto D, Terashita Y, Li C, Wakayama S, et al. (2012) Fluorescence Cell Imaging and Manipulation Using Conventional Halogen Lamp Microscopy. PLoS ONE 7(2): e31638. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031638		Yamagata K, Iwamoto D, Terashita Y, Li C, Wakayama S, et al. (2012) Fluorescence Cell Imaging and Manipulation Using Conventional Halogen Lamp Microscopy. PLoS ONE 7(2): e31638. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031638

Z8600021: /* 2012 */

2012-10-25T01:31:45Z

2012

← Older revision		Revision as of 11:31, 25 October 2012
Line 13:		Line 13:

	Yamagata K, Iwamoto D, Terashita Y, Li C, Wakayama S, et al. (2012) Fluorescence Cell Imaging and Manipulation Using Conventional Halogen Lamp Microscopy. PLoS ONE 7(2): e31638. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031638		Yamagata K, Iwamoto D, Terashita Y, Li C, Wakayama S, et al. (2012) Fluorescence Cell Imaging and Manipulation Using Conventional Halogen Lamp Microscopy. PLoS ONE 7(2): e31638. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031638


			===Functional Analysis of Lysosomes During Mouse Preimplantation Embryo Development===
			J Reprod Dev. 2012 Oct 19.

			Tsukamoto S, Hara T, Yamamoto A, Ohta Y, Wada A, Ishida Y, Kito S, Nishikawa T, Minami N, Sato K, Kokubo T.
			Source
			Laboratory Animal and Genome Sciences Section, National Institute of Radiological Sciences, Chiba 263-8555, Japan.

			Abstract

			Lysosomes are acidic and highly dynamic organelles that are essential for macromolecule degradation and many other cellular functions. However, little is known about lysosomal function during early embryogenesis. Here, we found that the number of lysosomes increased after fertilization. Lysosomes were abundant during mouse preimplantation development until the morula stage, but their numbers decreased slightly in blastocysts. Consistently, the protein expression level of mature cathepsins B and D was high from the one-cell to morula stages but low in the blastocyst stage. One-cell embryos injected with siRNAs targeted to both lysosome-associated membrane protein 1 and 2 (LAMP1 and LAMP2) were developmentally arrested at the two-cell stage. Pharmacological inhibition of lysosomes also caused developmental retardation, resulting in accumulation of lipofuscin. Our findings highlight the functional changes in lysosomes in mouse preimplantation embryos.

			PMID 23080372

	==2011==		==2011==

Z8600021 at 01:29, 25 October 2012

2012-10-25T01:29:41Z

← Older revision		Revision as of 11:29, 25 October 2012
Line 1:		Line 1:
	{{Talk Page}}		{{Talk Page}}


			==10 Most Recent==
			{{10 Most Recent}}
			===Blastocyst===
			<pubmed limit=10>Blastocyst</pubmed>




	==2012==		==2012==