title: The influence of follicle size, FSH-enriched maturation medium, and early cleavage on bovine oocyte maternal mRNA levels.
abstract: Transcription is arrested in the bovine oocyte within the first few hours of in vitro maturation, thus the stored maternal mRNAs accumulated in the oocyte are essential to sustain development until the Maternal-Zygotic Transition. In vivo matured oocytes have superior blastocyst formation rates than in vitro matured oocytes, suggesting that the mRNA content of these oocytes is of higher quality. To determine which transcripts may be associated with developmental competence, a Suppressive Subtractive Hybridization was performed between oocytes collected by ovariectomy at 6 hr post-LH surge and oocytes from slaughterhouse collected after 6 hr of maturation, resulting in a library enriched in these functionally important mRNAs. The clones were spotted onto a cDNA microarray and transcripts potentially associated with developmental competence were hybridized onto these slides. Hybridizations were performed with transcripts up-regulated in oocytes cultured for 6 hr in the presence or absence of rFSH in vitro, and secondly with transcripts up regulated in early-cleaving embryos versus those at the one-cell stage at 36 hr postfertilization. From these hybridizations, 13 candidates were selected. Their functional association with embryonic competence was validated by measuring their relative transcript levels by quantitative real-time PCR in eight different conditions: oocytes cultured with or without rFSH, early--versus late-cleaving embryos, and oocytes from different follicle sizes (1-3, 3-5, 5-8, and >8 mm of diameter). The gene candidates CCNB2, PTTG1, H2A, CKS1, PSMB2, SKIIP, CDC5L, RGS16, and PRDX1 showed a significant quantitative association with competence compared to BMP15, GDF9, CCNB1, and STK6.
authors.affiliation: Département des Sciences Animales, Centre de Recherche en Biologie de la Reproduction, Université Laval, Sainte Foy, Québec, Canada.
authors.forename: Marina
authors.initials: M
authors.lastname: Mourot
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dufort
authors.forename: Catherine
authors.initials: C
authors.lastname: Gravel
authors.forename: Omran
authors.initials: O
authors.lastname: Algriany
authors.forename: Steph
authors.initials: S
authors.lastname: Dieleman
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Sirard
mesh_terms: D000818:Animals; D002417:Cattle; D002970:Cleavage Stage, Ovum / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000032:analysis / Q000494:pharmacology*; D018507:Gene Expression Regulation, Developmental; D020411:Oligonucleotide Array Sequence Analysis; D009865:Oocytes / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D006080:Ovarian Follicle / Q000033:anatomy & histology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism
chemical_list: D003470:Culture Media; D012333:RNA, Messenger; D005640:Follicle Stimulating Hormone