title: Gene expression profile of cumulus cells derived from cumulus-oocyte complexes matured either in vivo or in vitro.
abstract: Although it is well established that maturation conditions have a clear influence on oocyte developmental competence, it is not known whether this could be due to downstream effects of perturbation of the transcript profile of the oocyte's adjacent cumulus cells. Therefore, the aim of the present study was to compare the transcript profiles of cumulus cells derived from cumulus-oocyte complexes (COCs) matured in vitro or in vivo. Using a previously validated combined synchronisation and superstimulation protocol, COCs were recovered from beef heifer ovaries just before the expected time of the LH surge and matured in vitro, while in vivo-matured COCs were recovered just before ovulation (20 h after the LH surge). A custom-made cDNA microarray containing 2278 granulosa/cumulus transcripts was used for target and dye-swap hybridisations. In all, 64 genes were differentially expressed between the two groups. Transcript abundance of key genes associated with cumulus expansion (TNFAIP6) and regulation of oocyte maturation (INHBA and FST) were upregulated in in vivo-derived cumulus cells. However, cumulus cells derived from IVM COCs were enriched with genes involved in response to stress (HSPA5 and HSP90AB1). Quantitative real-time polymerase chain reaction confirmed the array results for eight of 10 genes selected for validation. The data presented here reveal that differences in oocyte developmental capacity after maturation in vitro or in vivo are accompanied by distinct differences in transcript abundance of the surrounding cumulus cells.
authors.affiliation: Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, 53115 Bonn, Germany.
authors.forename: Dawit
authors.initials: D
authors.lastname: Tesfaye
authors.forename: Nasser
authors.initials: N
authors.lastname: Ghanem
authors.forename: Fiona
authors.initials: F
authors.lastname: Carter
authors.forename: Trudee
authors.initials: T
authors.lastname: Fair
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Sirard
authors.forename: Michael
authors.initials: M
authors.lastname: Hoelker
authors.forename: Karl
authors.initials: K
authors.lastname: Schellander
authors.forename: Patrick
authors.initials: P
authors.lastname: Lonergan
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D054885:Cumulus Cells / Q000737:chemistry* / Q000502:physiology*; D005260:Female; D020869:Gene Expression Profiling / Q000662:veterinary*; D007986:Luteinizing Hormone / Q000097:blood; D020411:Oligonucleotide Array Sequence Analysis / Q000662:veterinary; D009865:Oocytes / Q000254:growth & development*; D010060:Ovulation; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D012333:RNA, Messenger; D007986:Luteinizing Hormone