Zi Xiang-Dong, Lu Hong, Yin Rong-Hua, Chen Shao-Wei
College of Life Science and Technology, Southwest University for Nationalities, Chengdu, Sichuan 610041, PR China.
Anim Reprod Sci. 2008 Oct;108(1-2):208-15. doi: 10.1016/j.anireprosci.2007.08.005. Epub 2007 Aug 19.
The objectives of this study were to investigate differences in fertilization and development of embryos after in vitro fertilization of Bos taurus (cow) oocytes with sperm from either yaks (Bos grunniens) or Holstein bulls. Frozen-thawed spermatozoa (Holstein n=5 sires; yak n=5 sires) were evaluated for motility (forward progression) and acrosomal status immediately post-thaw and then 1, 2, 3, and 8h later. In vitro-matured cow oocytes (n=1652) were inseminated with either Holstein bull or yak spermatozoa and after an 18-h co-incubation period, a proportion of the oocytes were fixed and examined for sperm penetration, polyspermy, and male pronuclear formation. The remaining oocytes were cultured in vitro and evaluated for cleavage and blastocyst production rates. Overall, there were species differences (P<0.05) and an effect of time (P<0.01) in sperm motility and acrosome integrity. An effect (P<0.01) of a species-by-time interaction was detected for motility, but not for acrosome integrity. The percentage of oocytes penetrated and the formation of two pronuclei when cow oocytes were inseminated with yak spermatozoa (97.4% and 81.6%, respectively) were greater (P<0.01) than that achieved with Holstein bull spermatozoa (77.8% and 65.9%, respectively), but the incidence of polyspermy (>2 pronuclei) was similar (P>0.05; 10.8% vs. 15.8%). The yak male symbolxcow combination gave a higher cleavage rate than the Holstein male symbolxcow combination (P<0.05; 76.3% vs. 63.3%), but there was no difference in the blastocyst rate (17.9% vs. 14.5%). It is concluded that yak spermatozoa could successfully fertilize cattle oocytes and their hybrid embryos had normal competence to develop to blastocysts.
本研究的目的是调查用牦牛（牦牛属）或荷斯坦公牛的精子对黄牛（牛）卵母细胞进行体外受精后，胚胎受精和发育的差异。对冷冻解冻后的精子（荷斯坦公牛5头；牦牛5头）在解冻后立即以及随后1、2、3和8小时评估其活力（向前运动）和顶体状态。将体外成熟的牛卵母细胞（n = 1652）用荷斯坦公牛或牦牛精子进行授精，在18小时的共同孵育期后，一部分卵母细胞被固定并检查精子穿透、多精受精和雄原核形成情况。其余卵母细胞进行体外培养，并评估其分裂率和囊胚产生率。总体而言，精子活力和顶体完整性存在物种差异（P<0.05）和时间效应（P<0.01）。检测到物种与时间相互作用对活力有影响（P<0.01），但对顶体完整性无影响。当用牦牛精子对牛卵母细胞进行授精时，卵母细胞穿透率和双原核形成率（分别为97.4%和81.6%）高于用荷斯坦公牛精子授精（分别为77.8%和65.9%，P<0.01），但多精受精（>2个原核）发生率相似（P>0.05；10.8%对15.8%）。牦牛♂×牛♀组合的分裂率高于荷斯坦公牛♂×牛♀组合（P<0.05；76.3%对63.3%），但囊胚率无差异（17.9%对14.5%）。得出的结论是，牦牛精子能够成功使牛卵母细胞受精，并且它们的杂交胚胎具有发育到囊胚的正常能力。
