Effect of serum and cumulus cell expansion on marker gene transcripts in bovine cumulus-oocyte complexes during maturation in vitro.
OBJECTIVE
To determine the distribution of transcripts encoding the FSH receptor (FSHr), LH receptor (LHr), connexin 43 (Cx43), cyclooxygenase-2 (COX-2), and prostaglandin E(2) receptors 2 and 3 (EP2 and EP3) within bovine cumulus-oocyte complexes (COCs) and denuded oocytes and investigate the influence of gonadotropins, serum, and cumulus cell expansion on the abundance of transcripts encoding these genes.


METHODS
Prospective controlled animal study.


METHODS
University research laboratory.


METHODS
Animal models for human studies.


METHODS
Cumulus-oocyte complexes were treated in culture with serum and gonadotropin-supplemented media to examine the effects to mRNA transcript levels.


METHODS
Variation in mRNA transcript levels.


RESULTS
Luteinizing hormone receptor, FSHr, and EP3 mRNAs were detected in intact COCs and not in cumulus cell-denuded oocytes, whereas Cx43, COX-2, and EP2 mRNAs were found in both COCs and oocytes. The relative abundance of marker gene mRNAs did not vary in media containing no additives or FSH alone, independent of whether the media induced cumulus cell expansion. However, the presence of serum in maturation media significantly decreased expression of all mRNAs except LHr.


CONCLUSIONS
The relative abundance of COC mRNAs is altered by serum in the maturation medium, which may signify long-term consequences for embryonic development.
Calder
Michele D
MD
Department of Obstetrics and Gynecology, University of Western Ontario, London, Ontario, Canada. Michele.Calder@fmd.uwo.ca
Caveney
Anita N
AN
Sirard
Marc-Andre
MA
Watson
Andrew J
AJ
D000818:Animals; D001798:Blood Proteins / Q000494:pharmacology*; D002417:Cattle; D051546:Cyclooxygenase 2; D005260:Female; D005307:Fertilization in Vitro; D015870:Gene Expression / Q000187:drug effects; D005819:Genetic Markers; D006062:Gonadotropins / Q000494:pharmacology; D066298:In Vitro Techniques; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D011962:Receptors, FSH / Q000235:genetics; D011974:Receptors, LH / Q000235:genetics; D018078:Receptors, Prostaglandin E / Q000235:genetics; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058308:Receptors, Prostaglandin E, EP3 Subtype; D014158:Transcription, Genetic / Q000187:drug effects*
D001798:Blood Proteins; D005819:Genetic Markers; D006062:Gonadotropins; C545644:PTGER2 protein, human; C545647:PTGER3 protein, human; D012333:RNA, Messenger; D011962:Receptors, FSH; D011974:Receptors, LH; D018078:Receptors, Prostaglandin E; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058308:Receptors, Prostaglandin E, EP3 Subtype; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases