Linked Life Data

16319287

Source:http://linkedlifedata.com/resource/pubmed/id/16319287

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-2-21
pubmed:abstractText
Mammalian immature oocytes contain large nuclei referred to as germinal vesicles (GVs). The translocation of maturation/M-phase promoting factor (MPF) into GVs just before the activation of MPF has been reported in several species. To examine whether the GV is required for MPF activation in mammalian oocytes, porcine immature oocytes were enucleated and their MPF activity and CCNB (also known as cyclin B) levels were investigated. The activation of MPF at the start of maturation was detected at normal levels in enucleated oocytes, whereas reactivation to induce the second meiosis was not observed. Although protein synthesis was found to be normal both qualitatively and quantitatively, even in the absence of the nucleus, CCNB1 did not sufficiently accumulate in the enucleated oocytes. The defects in the enucleated oocytes were reversed by the injection of GV material into the enucleated oocytes. Furthermore, the inhibition of CCNB1 degradation revealed drastic accumulation of CCNB1, indicating active synthesis of CCNB1 in enucleated oocytes. The mitogen-activated protein kinase cascade remained unaffected by enucleation. These results indicate that GV is not required for the activation of MPF during the first meiosis, but that it is required for the second meiosis because of its promotion of CCNB1 accumulation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3363
pubmed:author
pubmed:issnType
Print
pubmed:volume
74
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
593-600
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Study of germinal vesicle requirement for the normal kinetics of maturation/M-phase-promoting factor activity during porcine oocyte maturation.
pubmed:affiliation
Department of Animal Resource Sciences, Graduate School of Agricultural Sciences, University of Tokyo, Tokyo 113-8657, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't