title: Estrus synchronization and ovarian hyper-stimulation treatments have negligible effects on cumulus oocyte complex gene expression whereas induction of ovulation causes major expression changes.
abstract: The effects of exogenous hormones, used for estrus synchronization and ovarian hyper stimulation, on cumulus oocyte complexes (COCs) gene expression in sexually mature rats were determined using microarrays. Gene expression in COCs collected from GnRH (G(trt)), GnRH + eCG (G + E(trt)), and GnRH + eCG + hCG (G + E + H(trt)) treatments were compared to COCs from naturally cycling (NC) rats before the preovulatory luteninizing hormone surge. There was no significant difference in gene expression among NC, G(trt), and G + E(trt); however, over 2,600 genes were significantly different between NC and G + E + H(trt) (P < 0.05). Genes upregulated in G + E + H(trt) encode for: proteins that are involved in prostaglandin synthesis (Ptgs2, Pla2g4a, and Runx1) and cholesterol biosynthesis (Hmgcr, Sc4mol, and Dhcr24); receptors that allow cholesterol uptake (Ldlr and Scarb1), regulate progesterone synthesis (Star), and inactivate estrogen (Sult1e1); and downstream effectors of LH signal (Pgr, Cebpb, Creb3l1, Areg, Ereg, and Adamts1). Conversely, G + E + H(trt) downregulated genes encoding proteins involved in: DNA replication and cell cycle progression (Ccne2, Orc5l, Rad50, and Mcm6); reproductive developmental process; and granulosa cell expansion (Gdf9, Bmp15, Amh, Amhr2, Bmpr1b, Tgfb2, Foxl2, Pde3a, Esr2, Fshr, Ybx2, Ccnd2, Ccnb1ip1, and Zp3); maternal effect genes required for embryo development (Zar1, Npm2, Nlrp5, Dnmt1, H1foo, and Zfp57); amino acid degradation; and ketogenesis (Hmgcs2, and Cpt1b). These results from the rat show that hormones used for estrus synchronization (G(trt)) and ovarian hyper stimulation (G + E(trt)) had minimal effects on gene expression, whereas induction of ovulation (G + E + H(trt)) caused major changes in gene expression of rat COCs. This study provides comprehensive information about regulated genes during late follicle development and ovulation induction.
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, Missouri 65211, USA.
authors.forename: Cansu
authors.initials: C
authors.lastname: Agca
authors.forename: Akin
authors.initials: A
authors.lastname: Yakan
authors.forename: Yuksel
authors.initials: Y
authors.lastname: Agca
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism; D054885:Cumulus Cells / Q000166:cytology / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004973:Estrus Synchronization / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007150:Immunohistochemistry; D046228:Microarray Analysis; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D010060:Ovulation / Q000502:physiology*; D010062:Ovulation Induction / Q000379:methods*; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D018797:Cell Cycle Proteins; D017931:DNA Primers; D007987:Gonadotropin-Releasing Hormone