China Animal Husbandry and Veterinary Medicine ›› 2022, Vol. 49 ›› Issue (12): 4707-4714.doi: 10.16431/j.cnki.1671-7236.2022.12.020

• Genetics and Breeding • Previous Articles     Next Articles

Effects of Vitamin A on the Maturation and Subsequent Development of Yak Oocytes in vitro

JI Wenhui1, WANG Yuling1, HE Honghong1, FU Wei1, LAN Daoliang1,2   

  1. 1. College Animal & Veterinary Sciences, Southwest Minzu University, Chengdu 610065, China;
    2. Ministry of Education of Key Laboratory of Qinghai-Tibet Plateau Animal Genetic Resource and Utilization, Chengdu 610065, China
  • Received:2022-05-24 Online:2022-12-05 Published:2022-12-01

Abstract: 【Objective】 The aim of this study was to explore the effects of vitamin A on in vitro maturation and subsequent embryo development of yak oocytes.【Method】 Yak oocytes were taken as the research object, and vitamin A of 0 (control group), 2, 5, 10 and 20 μmol/L was added to the in vitro maturation culture medium, and the first polar body excretion rate was counted after in vitro culture for 24 h.Parthenogenetic activation was carried out on matured oocytes in each group.After activation, the cleavage rate and blastocyst rate were counted at the 2nd and 8th days, respectively.The relative expression of node genes, including RARα, RARβ, RARγ, RXRα, RXRβ, RXRγ and STRA8 genes in typical signaling pathways and MEK and ERK1 genes in atypical signaling pathways were detected by Real-time quantitative PCR in MⅡ oocyte stage, and the optimal treatment concentration of vitamin A was selected.The optimal concentration of vitamin A was added to the in vitro maturation medium, and oocytes in MⅠ and MⅡ stage were collected at 6 and 24 hours of maturation.Some MⅡ oocytes were parthenogeneously activated, and blastocysts were collected at 8 days after activation.The relative expression of RARα, RXRα and STRA8 genes in GV, MⅠ and MⅡ oocytes and parthenogeneously activated blastocysts were detected by real-time fluorescence quantitative PCR.【Result】 Compared with control group, the first polar body excretion rate and cleavage rate of 2, 5 and 10 μmol/L vitamin A groups were significantly increased (P<0.05), and reached the highest in 2 μmol/L vitamin A group.The blastocyst rate of 2 μmol/L vitamin A group was increased significantly (P<0.05), while the first polar body excretion rate, cleavage rate and blastocyst rate of 20 μmol/L vitamin A group were decreased significantly (P<0.05).The results of Real-time quantitative PCR showed that compared with control group, the relative expressions of RARα, RXRα and STRA8 genes in 2, 5, 10 and 20 μmol/L vitamin A groups were significantly increased (P<0.05), among which the 2 μmol/L vitamin A group was the highest, so 2 μmol/L vitamin A had the best effect on the in vitro maturation of yak oocytes.Compared with GV stage oocytes, the relative expression of STRA8, RXRα and RARα genes in MⅡ stage oocytes were extremely significantly increased (P<0.01), but there was no significant difference between MⅠ stage oocytes and blastocyst (P>0.05).【Conclusion】 The addition of 2 μmol/L vitamin A could promote the maturation of yak oocytes in vitro and significantly increase the cleavage rate of the parthenogeneously activated blastocysts, and vitamin A regulated the maturation of yak oocytes mainly through typical signaling pathways.

Key words: vitamin A; oocytes; parthenogenetic activation; typical signal pathway

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