title: Developmental competence and gene expression of immature oocytes following liquid helium vitrification in bovine.
abstract: The objective of this study was to develop an effective ultra-rapid vitrification method and evaluate its effect on maturation, developmental competence and development-related gene expression in bovine immature oocytes. Bovine cumulus oocyte complexes were randomly allocated into three groups: (1) controls, (2) liquid nitrogen vitrification, and (3) liquid helium vitrification. Oocytes were vitrified and then warmed, the percentage of morphologically normal oocytes in liquid helium group (89.0%) was significantly higher (P<0.05) than that of the liquid nitrogen group (81.1%). When the vitrified-thawed oocytes were matured in vitro for 24h, the maturation rate in liquid helium group (50.6%) was higher (P<0.05) than liquid nitrogen group (42.6%). Oocytes of liquid helium vitrification had higher cleavage and blastocyst rates (41.1% and 10.0%) than that of liquid nitrogen vitrification (33.0% and 4.5%; P<0.05) after in vitro fertilization. Moreover, the expression of GDF9 (growth/differentiation factor-9), BAX (apoptosis factor) and ZAR1 (zygote arrest 1) was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) when the vitrified-thawed oocytes were matured 24h. The expression of these genes was altered after vitrification. Expression of GDF9 and BAX in the liquid helium vitrification group was not significantly different from that of the control, however there were significant differences between the liquid nitrogen vitrification group and control. In conclusion, it was feasible to use liquid helium for vitrifying bovine immature oocytes. There existed an association between the compromised developmental competence and the altered expression levels of these genes for the vitrified oocytes.
authors.affiliation: College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China; Henan Provincial Key Laboratory for Grass-Feeding Animal, Henan University of Science and Technology, Luoyang 471003, China.
authors.forename: Jun-Yi
authors.initials: JY
authors.lastname: Chen
authors.affiliation: College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China; Henan Provincial Key Laboratory for Grass-Feeding Animal, Henan University of Science and Technology, Luoyang 471003, China.
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Li
authors.affiliation: College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China; Henan Provincial Key Laboratory for Grass-Feeding Animal, Henan University of Science and Technology, Luoyang 471003, China.
authors.forename: Ya-Kun
authors.initials: YK
authors.lastname: Xu
authors.affiliation: College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China; Henan Provincial Key Laboratory for Grass-Feeding Animal, Henan University of Science and Technology, Luoyang 471003, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wu
authors.affiliation: College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China; Henan Provincial Key Laboratory for Grass-Feeding Animal, Henan University of Science and Technology, Luoyang 471003, China.
authors.forename: Jun-Jun
authors.initials: JJ
authors.lastname: Zheng
authors.affiliation: College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China; Henan Provincial Key Laboratory for Grass-Feeding Animal, Henan University of Science and Technology, Luoyang 471003, China. Electronic address: yxl4282333@126.com.
authors.forename: Xue-Li
authors.initials: XL
authors.lastname: Yu
mesh_terms: D000818:Animals; D002417:Cattle / Q000196:embryology / Q000502:physiology*; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D047108:Embryonic Development; D005260:Female; D005307:Fertilization in Vitro; D018507:Gene Expression Regulation, Developmental; D006371:Helium / Q000737:chemistry; D008297:Male; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D058989:Vitrification
chemical_list: D006371:Helium
keywords: Bovine; Developmental competence; Gene expression; Immature oocytes; Liquid helium vitrification; QRT-PCR