Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2002-10-25
pubmed:databankReference
pubmed:abstractText
In contrast to other species, the preovulatory rise in gonadotropins in mares causes a remarkable expansion of the entire granulosa cell layer in vivo, suggesting that hyaluronan (HA) synthesis may be regulated in mural granulosa cells in this species. The objectives of this study were to clone and characterize equine hyaluronan synthase 2 (HAS2) and investigate the regulation of its transcript and of HA synthesis in equine follicles during human chorionic gonadotropin (hCG)- induced ovulation. Results showed that the equine HAS2 cDNA contains a 5'-untranslated region of 436 bp, an open reading frame of 1659 bp, and a 3'-untranslated region of 707 bp. The open reading frame encodes a 552-amino acid protein that is highly conserved (98-99% identity), compared with other known mammalian homologs. The regulation of HAS2 mRNA was studied in equine follicles isolated during estrus between 0 and 39 h after an ovulatory dose of hCG and in corpora lutea obtained on d 8 of the estrous cycle. Results from semiquantitative RT-PCR/Southern blotting analyses revealed a transient induction of HAS2 during the ovulatory process. Levels of HAS2 transcripts were undetectable in follicles before hCG treatment (0 h), increased markedly after gonadotropin treatment (P < 0.05), but returned to undetectable levels in corpora lutea. Analyses performed on isolated preparations of theca interna and granulosa cells showed that the granulosa cell layer was the predominant site of HAS2 expression. An immunohistochemical approach showed that this induction of HAS2 transcript was accompanied by a dramatic increase in HA production after hCG treatment. The isolation and characterization of a 1.8-kb fragment of genomic sequence located immediately upstream of equine HAS2, and comparison with corresponding human and mouse genomic regions identified several conserved putative cis-acting elements. Thus, this study describes the primary structure of equine HAS2, demonstrates for the first time the regulation of HAS2 in mural granulosa cells during the ovulatory process in vivo and identifies a valuable model in which to study the molecular control of HAS2 gene expression.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
143
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4375-84
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:12399434-Amino Acid Sequence, pubmed-meshheading:12399434-Animals, pubmed-meshheading:12399434-Base Sequence, pubmed-meshheading:12399434-Chorionic Gonadotropin, pubmed-meshheading:12399434-Corpus Luteum, pubmed-meshheading:12399434-DNA, Complementary, pubmed-meshheading:12399434-Female, pubmed-meshheading:12399434-Gene Expression Regulation, Enzymologic, pubmed-meshheading:12399434-Glucuronosyltransferase, pubmed-meshheading:12399434-Granulosa Cells, pubmed-meshheading:12399434-Horses, pubmed-meshheading:12399434-Humans, pubmed-meshheading:12399434-Hyaluronic Acid, pubmed-meshheading:12399434-Mice, pubmed-meshheading:12399434-Molecular Sequence Data, pubmed-meshheading:12399434-Organ Specificity, pubmed-meshheading:12399434-Ovarian Follicle, pubmed-meshheading:12399434-Ovulation, pubmed-meshheading:12399434-Promoter Regions, Genetic, pubmed-meshheading:12399434-RNA, Messenger, pubmed-meshheading:12399434-Sequence Homology
pubmed:year
2002
pubmed:articleTitle
Induction of hyaluronan synthase 2 by human chorionic gonadotropin in mural granulosa cells of equine preovulatory follicles.
pubmed:affiliation
Centre de Recherche en Reproduction Animale, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec J2S 7C6, Canada.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't