Linked Life Data

583426

Source:http://linkedlifedata.com/resource/pubmed/id/583426

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1980-5-23
pubmed:abstractText
Mouse blastocysts undergo developmental steps in culture analogous to those occurring during implantation in utero. We examined cultured blastocysts by scanning electron microscopy (SEM) as they passed through these stages. From the time of hatching to the acquisition of adhesiveness, most blastocysts were exhanded, with flattened cells possessing relatively small numbers of microvilli, centrally raised areas (presumably reflecting the location of the nuclei) and intercellular ridges often possessing microvilli. At, or shortly before, the trophoblast outgrowth stage, blastocysts appeared to contract; the cells bulged noticeably, microvilli covered the entire surface of most cells and intercellular ridges were no longer observable. Blastocysts removed from uteri on the seventh day of ovariectomy delay possessed a variety of morphologies and shapes. The blastocoel was frequently collapsed and cell outlines were difficult to discern. These blastocysts were initially adhesive in vitro, but subsequently disengaged from the substratum before becoming permanently adherent several hours later. During the initial phase of adhesiveness, blastocysts were elongated and had prominent intercellular ridges, particularly in the equatorial region. Detached blastocysts contained bulging cells with contours which obscured the intercellular ridges. Surface ultrastructure during subsequent phases resembled non-delayed blastocysts during attachment and outgrowth. On the basis of our studies, we propose that intercellular ridges play some role in blastocyst adhesiveness. However, we must conclude that there are other factors involved in the acquisition of adhesiveness by the blastocyst which are at least equally important but of a nature too subtle to be identified by our SEM analyses. Insofar as delayed blastocysts are concerned, we find that, within limits, the surface alterations that take place when blastocysts are activated in culture mirror those observed following reversal of delay in vivo by administration of hormones. Since delayed blastocysts placed in saline also undergo morphological changes resembling those seen at the onset of activation in utero, we suggest that reversal of implantation delay requires initially neither direct contact with steroid or macromolecular inducers nor an exogenous supply of metabolites.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-104X
pubmed:author
pubmed:issnType
Print
pubmed:volume
210
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
69-80
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Scanning electron microscopy of the surface of normal and implantation-delayed mouse blastocysts during development in vitro.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro