Abstract:

【Objective】 This study was made to investigate the effect of LH on maturation and fertilization in vitro of ovine oocytes. 【Method】 The ovine oocytes were matured in vitro with or without LH, and checked by confocal laser scanning microscope to observe the distribution of cortical granules during different durations stained with FITC-LCA. Meanwhile, some in vitro matured oocytes were also fertilized in vitro for analysis of their developmental potentiality further. 【Result】 After 4 h of culture, there were significant differences in the rate of GVBD between the treatment (with LH) and control (without LH) groups (36.76% vs 50%, P＜0.05), moreover, there were also significant differences in cleavage rate and blastocyst rate, respectively, between these two groups (67.15% vs 42.37%, 21.9% vs 12.71%, P＜0.05). The distribution of cortical granules appeared to spread from the edges to the central site of sheep oocytes following their in vitro maturation durations. 【Conclusion】 LH plaies a role to delay the occurrence of germinal vesicle, prolong the maturation duration of cytoplasm,enhance the nuclear and cytoplasm synchronization of ovine oocytes matured in vitro, and finally improve the potentiality of their in vitro development.

Key words: ovine, oocyte, luteinizing hormone, in vitro maturation, nuclear and cytoplasm synchronization