卵泡表面直径判断山羊卵母细胞的发育能力

Judging the Developmental Potential of Caprine Oocytes by Surface Diameters of Follicles

试验探讨了山羊卵泡表面直径与实际直径的相关性及卵泡直径与卵母细胞直径和卵母细胞发育能力的关系。结果显示:(1)山羊卵巢表面直径1.5～2.5mm以上卵泡,其表面直径和实测直径相关性显著(r=0.72),可以利用表面直径对这群卵泡进行分类;(2)表面直径1.5～2.5mm以上卵泡,其卵母细胞已经达到最大直径(约130μm),透明带体积也达到最大(约7×105μm3);在此之前的有腔卵泡,卵母细胞直径和透明带体积均随着卵泡直径增加而增加;(3)不同直径卵泡其卵母细胞减数分裂能力不同:≤0.5mm直径卵泡卵母细胞未获得恢复减数分裂的能力;0.8～1.2mm直径卵泡卵母细胞可恢复减数分裂,但只能发育到M 期;1.5～2.5mm和3.0～5.0mm直径卵泡卵母细胞可恢复减数分裂并发育到M 期,24h时M 期比率分别为93%和91%。

In this study, the correlations of the surface diameter (SD) with the dissected diameter (DD) of follicles and with diameter and developmental capacity of oocytes were investigated in goats. The results were summarized as follows: (1) The SD and DD in follicles with a SD larger than 1.5~2.5 mm were closely correlated (r= 0.72), indicating that follicles in this group could be classified in accordance with their surface diameter. (2) Oocytes from follicles larger than 1.5～2.5 mm in surface diameter had achieved the maximal diameter (about 130μm) and the maximal volume of zona pellucida (ZP) (about 7×10~5 μm^3). In the antral-follicles smaller than 1.5 mm, oocyte diameter and ZP volume increased with follicular growth. (3) Oocytes from different sized follicles showed different meiotic competence. Oocytes from ≤0.5 mm follicles were unable to resume meiosis; Oocytes from 0.8～1.2 mm follicles were able to resume meiosis, but stopped at MⅠ (metaphase-Ⅰ) stage; Oocytes from 1.5～2.5 mm and 3.0～5.0 mm follicles resumed meiosis and developed to MⅡ (metaphase-Ⅱ) at 93% and 91%, respectively, after 24 h of culture.