title: Identification of molecular markers for oocyte competence in bovine cumulus cells.
abstract: Cumulus cells (CCs) have an important role during oocyte growth, competence acquisition, maturation, ovulation and fertilization. In an attempt to isolate potential biomarkers for bovine in vitro fertilization, we identified genes differentially expressed in bovine CCs from oocytes with different competence statuses, through microarray analysis. The model of follicle size, in which competent cumulus-oocyte complexes (COCs) were recovered from bigger follicles (≥8.0 mm in diameter) and less competent ones from smaller follicles (1-3 mm), was used. We identified 4178 genes that were differentially expressed (P < 0.05) in the two categories of CCs. The list was further enriched, through the use of a 2.5-fold change in gene expression as a cutoff value, to include 143 up-regulated and 80 down-regulated genes in CCs of competent COCs compared to incompetent COCs. These genes were screened according to their cellular roles, most of which were related to cell cycle, DNA repair, energy metabolism, metabolism of amino acids, cell signaling, meiosis, ovulation and inflammation. Three candidate genes up-regulated (FGF11, IGFBP4, SPRY1) and three down-regulated (ARHGAP22, COL18A1 and GPC4) in CCs from COCs of big follicles (≥8.1 mm) were selected for qPCR analysis. The selected genes showed the same expression patterns by qPCR and microarray analysis. These genes may be potential genetic markers that predict oocyte competence in in vitro fertilization routines.
authors.affiliation: Embrapa- Genetic Resources and Biotechnology, Brasília, DF, 70770-917, Brazil.
authors.forename: E O
authors.initials: EO
authors.lastname: Melo
authors.affiliation: School of Agriculture and Veterinary Medicine, University of Brasilia, Brasília, DF, 70910-900, Brazil.
authors.forename: D M
authors.initials: DM
authors.lastname: Cordeiro
authors.affiliation: Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
authors.forename: R
authors.initials: R
authors.lastname: Pellegrino
authors.affiliation: Department of Computer Science, New Jersey Institute of Technology, Newark, NJ, 07102, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Division of Epidemiology and Biostatistics, University of Arizona, Tucson, AZ, 85721, USA.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Daye
authors.affiliation: School of Agriculture and Veterinary Medicine, University of Brasilia, Brasília, DF, 70910-900, Brazil.
authors.forename: R C
authors.initials: RC
authors.lastname: Nishimura
authors.affiliation: Embrapa- Genetic Resources and Biotechnology, Brasília, DF, 70770-917, Brazil.
authors.forename: M A N
authors.initials: MA
authors.lastname: Dode
mesh_terms: D000818:Animals; D002417:Cattle; D054885:Cumulus Cells / Q000502:physiology*; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D005819:Genetic Markers; D046228:Microarray Analysis; D009865:Oocytes / Q000502:physiology*; D009866:Oogenesis / Q000235:genetics
chemical_list: D005819:Genetic Markers
keywords: cattle; gene expression; microarray; oocyte quality