title: Functional role of the bovine oocyte-specific protein JY-1 in meiotic maturation, cumulus expansion, and subsequent embryonic development.
abstract: Oocyte-expressed genes regulate key aspects of ovarian follicular development and early embryogenesis. We previously demonstrated a requirement of the oocyte-specific protein JY-1 for bovine early embryogenesis. Given that JY-1 is present in oocytes throughout folliculogenesis, and oocyte-derived JY-1 mRNA is temporally regulated postfertilization, we hypothesized that JY-1 levels in oocytes impact nuclear maturation and subsequent early embryogenesis. A novel model system, whereby JY-1 small interfering RNA was microinjected into cumulus-enclosed germinal vesicle-stage oocytes and meiotic arrest maintained for 48 h prior to in vitro maturation (IVM), was validated and used to determine the effect of reduced oocyte JY-1 expression on nuclear maturation, cumulus expansion, and embryonic development after in vitro fertilization. Depletion of JY-1 protein during IVM effectively reduced cumulus expansion, percentage of oocytes progressing to metaphase II, proportion of embryos that cleaved early, total cleavage rates and development to 8- to 16-cell stage, and totally blocked development to the blastocyst stage relative to controls. Supplementation with JY-1 protein during oocyte culture rescued effects of JY-1 depletion on meiotic maturation, cumulus expansion, and early cleavage, but did not rescue development to 8- to 16-cell and blastocyst stages. However, effects of JY-1 depletion postfertilization on development to 8- to 16-cell and blastocyst stages were rescued by JY-1 supplementation during embryo culture. In conclusion, these results support an important functional role for oocyte-derived JY-1 protein during meiotic maturation in promoting progression to metaphase II, cumulus expansion, and subsequent embryonic development.
authors: Laboratory of Mammalian Reproductive Biology and Genomics, Michigan State University, East Lansing, Michigan.
authors: Kyung-Bon
authors: KB
authors: Lee
authors: Gabbine
authors: G
authors: Wee
authors: Kun
authors: K
authors: Zhang
authors: Joseph K
authors: JK
authors: Folger
authors: Jason G
authors: JG
authors: Knott
authors: George W
authors: GW
authors: Smith
mesh_terms: D000818:Animals; D001755:Blastocyst; D002417:Cattle; D002970:Cleavage Stage, Ovum / Q000187:drug effects; D054885:Cumulus Cells / Q000502:physiology*; D004527:Egg Proteins / Q000235:genetics / Q000502:physiology*; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D055785:Gene Knockdown Techniques; D008540:Meiosis / Q000502:physiology*; D008845:Microinjections; D009865:Oocytes / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D004527:Egg Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering
keywords: JY-1; cattle; cumulus; embryo; in vitro fertilization; oocyte; oocyte maturation; preimplantation