Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-9-21
pubmed:abstractText
Oxygen concentrations used during in vitro embryo culture can influence embryo development, cell numbers, and gene expression. Here we propose that the preimplantation bovine embryo possesses a molecular mechanism for the detection of, and response to, oxygen, mediated by a family of basic helix-loop-helix transcription factors, the hypoxia-inducible factors (HIFs). Day 5 compacting bovine embryos were cultured under different oxygen tensions (2%, 7%, 20%) and the effect on the expression of oxygen-regulated genes, development, and cell number allocation and HIFalpha protein localization were examined. Bovine in vitro-produced embryos responded to variations in oxygen concentration by altering gene expression. GLUT1 expression was higher following 2% oxygen culture compared with 7% and 20% cultured blastocysts. HIF mRNA expression (HIF1alpha, HIF2alpha) was unaltered by oxygen concentration. HIF2alpha protein was predominantly localized to the nucleus of blastocysts. In contrast, HIF1alpha protein was undetectable at any oxygen concentration or in the presence of the HIF protein stabilizer desferrioxamine (DFO), despite being detectable in cumulus cells following normal maturation conditions, acute anoxic culture, or in the presence of DFO. Oxygen concentration also significantly altered inner cell mass cell proportions at the blastocyst stage. These results suggest that oxygen can influence gene expression in the bovine embryo during postcompaction development and that these effects may be mediated by HIF2alpha.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3363
pubmed:author
pubmed:issnType
Print
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1108-19
pubmed:dateRevised
2007-4-11
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Oxygen-regulated gene expression in bovine blastocysts.
pubmed:affiliation
Research Centre for Reproductive Health, Department of Obstetrics and Gynaecology, The University of Adelaide, The Queen Elizabeth Hospital, Woodville, South Australia 5011, Australia. alexandra.harvey@adelaide.edu.au
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't