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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1998-2-6
pubmed:abstractText
A decrease in insulin-like growth factor (IGF) binding protein (BP) amount occurs within the follicular fluid of dominant ovarian follicles. At the same time, concentrations of follicular fluid IGF-I do not change. The mRNA for IGF-I, IGF-II, IGFBP-2, and IGFBP-3, in dominant and subordinate follicles were measured to determine if changes in IGF or IGFBP gene expression are associated with follicular dominance. Heifers were ovariectomized during a follicular wave, either during early-dominance (emerging dominant follicle, 9 mm diameter) or mid-dominance (established dominant follicle, 14-16 mm diameter). Follicles were classified as either dominant (DF), subordinate (SF), or not-recruited (NRF; small antral follicles). mRNA was localized by in situ hybridization and measured by image analyses. The IGF-I mRNA (granulosa cells) was greatest in DF and increased in DF, SF, and NRF from early- to mid-dominance. Likewise, IGF-II mRNA (theca cells) was greatest in DF compared with SF or NRF. The IGFBP-2 mRNA (granulosa cells), however, was nearly undetectable in DF, whereas adjacent SF expressed abundant IGFBP-2 mRNA. The NRF were not uniform in their IGFBP-2 expression because only 5 of 13 NRF had IGFBP-2 mRNA. The IGFBP-3 mRNA (granulosa cells) was found only in two NRF, suggesting that local synthesis is not a predominant source of follicular fluid IGFBP-3. These data show that changes in gene expression for IGFBP-2 are opposite to those for IGF-I or IGF-II. Increased IGF-I and IGF-II mRNA and decreased IGFBP-2 mRNA within the DF may be one mechanism leading to follicular dominance. The opposite pattern of IGFBP-2 gene expression in SF and some NRF may lead to follicular atresia.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0739-7240
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
55-63
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Follicular dominance in cattle is associated with divergent patterns of ovarian gene expression for insulin-like growth factor (IGF)-I, IGF-II, and IGF binding protein-2 in dominant and subordinate follicles.
pubmed:affiliation
Department of Animal Sciences, University of Missouri, Columbia 65211, USA.
pubmed:publicationType
Journal Article