Difference between revisions of "Blastocyst Development"

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[[File:Mouse-hatching blastocyst.jpg|thumb|200px|Blastocyst hatching from zona pellucida (mouse)]]
[[File:Mouse-hatching blastocyst.jpg|thumb|Blastocyst hatching from zona pellucida (mouse)]]
 
 
(Greek, ''blastos'' = sprout + ''cystos'' = cavity) or blastula, the term used to describe the hollow cellular mass that forms in early development. The blastocyst consists of cells forming an outer trophoblast layer, an inner cell mass and a fluid-filled cavity. The blastocyst inner cell mass is the source of true embryonic stem cells capable of forming all cell types within the embryo. In humans, this stage occurs in the first and second weeks after the [[zygote]] forms a solid cellular mass [[morula]] stage) and before implantation.
 
(Greek, ''blastos'' = sprout + ''cystos'' = cavity) or blastula, the term used to describe the hollow cellular mass that forms in early development. The blastocyst consists of cells forming an outer trophoblast layer, an inner cell mass and a fluid-filled cavity. The blastocyst inner cell mass is the source of true embryonic stem cells capable of forming all cell types within the embryo. In humans, this stage occurs in the first and second weeks after the [[zygote]] forms a solid cellular mass [[morula]] stage) and before implantation.
  

Revision as of 11:13, 8 October 2010

Blastocyst hatching from zona pellucida (mouse)

(Greek, blastos = sprout + cystos = cavity) or blastula, the term used to describe the hollow cellular mass that forms in early development. The blastocyst consists of cells forming an outer trophoblast layer, an inner cell mass and a fluid-filled cavity. The blastocyst inner cell mass is the source of true embryonic stem cells capable of forming all cell types within the embryo. In humans, this stage occurs in the first and second weeks after the zygote forms a solid cellular mass morula stage) and before implantation.


--Mark Hill 19:01, 5 August 2009 (EST) Page under development - notice removed when completed.


Inner Cell Mass

Trophoblast Layer

  • trophectoderm epithelium
  • transport of Na+ and Cl- ions through this layer into the blastocoel

Development Processes

Compaction

  • E-cadherin mediated adhesion initiates at compaction at the 8-cell stage
  • regulated post-translationally via protein kinase C and other signalling molecules

Blastocoel Formation

  • trophectoderm transports of Na+ and Cl- ions through this layer into the blastocoel
  • generates an osmotic gradient driving fluid across this epithelium
  • distinct apical and basolateral membrane domains specific for transport
  • facilitates transepithelial Na+ and fluid transport for blastocoel formation
  • transport is driven by Na, K-adenosine triphosphatase (ATPase) in basolateral membranes of the trophectoderm [1]


Molecular Factors

  • E-cadherin - Calcium ion-dependent cell adhesion molecule, a cell membrane adhesive protein required for morula compaction
  • epithin - A type II transmembrane serine protease, identified in mouse for compaction of the morula during preimplantation embryonic development. Expressed from 8-cell stage at blastomere contacts and co-localises in the morula with E-cadherin. PMID: 15848395
  • Na, K-adenosine triphosphatase - A sodium potassium pump that generates an osmotic gradient for fluid flow into the blastocoel
  • Zonula occludens-1 - (ZO-1) Tight junction protein involved in morula to blastocyst transformation in the mouse PMID: 18423437

References

  1. <pubmed>16139691</pubmed>


Articles

<pubmed>19289087, 18817772, 18083014</pubmed>

<pubmed>20157423</pubmed>

Search PubMed

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Search Pubmed: blastocyst development | blastocoel development | inner cell mass development | trophectoderm |


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Cite this page: Hill, M.A. (2021, March 8) Embryology Blastocyst Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Blastocyst_Development

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© Dr Mark Hill 2021, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G