title: Expression profiles of select genes in cumulus-oocyte complexes from young and aged mares.
abstract: There is compelling evidence that oocytes from mares >18 years of age have a high incidence of inherent defects that result in early embryonic loss. In women, an age-related decrease in oocyte quality is associated with an increased incidence of aneuploidy and it has recently been determined that the gene expression profile of human oocytes is altered with advancing age. We hypothesised that similar age-related aberrations in gene expression occur in equine oocytes. Therefore, the aim of the present study was to compare gene expression profiles of individual oocytes and cumulus cells from young and aged mares, specifically evaluating genes that have been identified as being differentially expressed with advancing maternal age and/or aneuploidy in human oocytes. Expression of 48 genes was compared between 14 cumulus-oocyte complexes (COCs) from mares aged 3-12 years and 10 COCs from mares ≥18 years of age. Three genes (mitochondrial translational initiation factor 3 (IF3), heat shock transcription factor 5 (HSF5) and Y box binding protein 2 (YBX2)) were differentially expressed in oocytes, with all being more abundant in oocytes from young mares. Three genes (ADP-ribosylation factor-like 6 interacting protein 6 (ARL6IP6), BCL2-associated X protein (BAX) and hypoxia upregulated 1 (HYOU1)) were differentially expressed in cumulus cells, with all being more abundant in aged mares. The results of the present study confirm there are age-related differences in gene expression in equine COCs, which may be associated with the lower quality and decreased developmental competence of oocytes from aged mares.
authors.affiliation: Department of Animal, Dairy and Veterinary Sciences, 4815 Old Main Hill, Utah State University, Logan, UT 84322-4815, USA.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Cox
authors.affiliation: Department of Animal, Dairy and Veterinary Sciences, 4815 Old Main Hill, Utah State University, Logan, UT 84322-4815, USA.
authors.forename: Dirk K
authors.initials: DK
authors.lastname: Vanderwall
authors.affiliation: Department of Animal, Dairy and Veterinary Sciences, 4815 Old Main Hill, Utah State University, Logan, UT 84322-4815, USA.
authors.forename: Kate C
authors.initials: KC
authors.lastname: Parkinson
authors.affiliation: Department of Animal, Dairy and Veterinary Sciences, 4815 Old Main Hill, Utah State University, Logan, UT 84322-4815, USA.
authors.forename: Alexis
authors.initials: A
authors.lastname: Sweat
authors.affiliation: Department of Animal, Dairy and Veterinary Sciences, 4815 Old Main Hill, Utah State University, Logan, UT 84322-4815, USA.
authors.forename: S Clay
authors.initials: SC
authors.lastname: Isom
mesh_terms: D000367:Age Factors; D000818:Animals; D054885:Cumulus Cells / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D000076249:Heat Shock Transcription Factors; D006736:Horses; D009865:Oocytes / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D000076249:Heat Shock Transcription Factors; D016601:RNA-Binding Proteins; D014157:Transcription Factors