title: Vitrification of in vitro matured ovine oocytes affects in vitro pre-implantation development and mRNA abundance.
abstract: The impact of vitrification procedures on in vitro matured (IVM) ovine oocytes mRNA content and ability to undergo successful fertilization, cleavage and embronic development was assessed. Vitrified-warmed (n = 113) and control (n = 140) IVM oocytes were in vitro fertilized and cultured up to blastocyst stage under standard conditions. Vitrified oocytes showed lower cleavage rate (47% vs. 75%, P < 0.001) and development to blastocyst stage (17% vs. 57%, P < 0.001) than controls. In addition, the timings of the first cleavage and blastocysts production were significantly delayed in the vitrified-warmed group (P < 0.001 in both cases). In parallel, we analyzed by reverse transcriptase real-time PCR the relative abundance of beta-actin, H2A.Z histone, Poli A Polimerase (PAP), Heat Shock Protein 90 beta (HSP90 beta), P34(cdc2), Cyclin b, Na/K-ATPase and Type I cadherin (E-Cad) transcripts in single IVM controls (n = 24) and vitrified-warmed oocytes (n = 40). Results were normalized against the exogenous rabbit alpha-globin mRNA standard and the beta-actin housekeeping gene and similarly described a lower abundance of most mRNAs in oocytes subjected to vitrification procedures. When normalized against the exogenous standard mRNA, all transcripts except for beta-actin and H2A.Z showed a significantly different abundance in the two classes of oocytes. The same results were obtained after normalization against the internal standard, except for HSP90 beta and E-Cad transcripts, whose lower abundance in vitrified-warmed oocytes resulted prominent, but not significant (P = 0.083 and P = 0.068, respectively). The oocyte lower transcripts abundance following vitrification might be an early indicator of poor quality in good correlation with the developmental data to blastocyst stage.
authors: Department of Animal Biology, University of Sassari, Sassari, Italy. succus@uniss.it
authors: Sara
authors: S
authors: Succu
authors: Daniela
authors: D
authors: Bebbere
authors: Luisa
authors: L
authors: Bogliolo
authors: Federica
authors: F
authors: Ariu
authors: Stefano
authors: S
authors: Fois
authors: Giovanni Giuseppe
authors: GG
authors: Leoni
authors: Fiammetta
authors: F
authors: Berlinguer
authors: Salvatore
authors: S
authors: Naitana
authors: Sergio
authors: S
authors: Ledda
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D015925:Cryopreservation; D004622:Embryo, Mammalian; D047108:Embryonic Development / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D009865:Oocytes / Q000502:physiology*; D009866:Oogenesis / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D012756:Sheep / Q000196:embryology*
chemical_list: D012333:RNA, Messenger