采用地衣红染色和免疫荧光的方法,观察了培养在基础培养液加BsA、血清、BSA+EGF和BSA+TGFα四组成熟培养液中绵羊卵母细胞的核成熟状态和α-微管蛋白分布。以及成熟培养后皮质颗粒(CG)的分布情况。结果表明培养22h的上述各组卵母细胞的核成熟率分别为63.5%、75.2%、73.1%、69.8%,处于第一次减数分裂末期的比率分别为27.0%、16.3%、15.9%、16.9%,EGF、TGFα和血清的添加明显提高了核的成熟率(P〈0.05),显著减少了处于第一减数分裂末期的比例(P〈0.05):α-微管蛋白的正常率(66.6%、66.6%、73.6%)也显著高于BSA组(43.3%)(P〈0.05):CG发生迁移较好的卵母细胞比率分别为33.9%、58.8%、54.7%、47.9%,与BSA组相比,EGF和血清的添加明显促进了CG向皮质区的迁移(P〈0.05)。实验表明TGFα和EGF均促进了绵羊卵母细胞成熟过程中从第一减数分裂末期向第二减数分裂中期的转变,并且能够替代血清中的某些成分促进和改善体外成熟卵母细胞核成熟的质量,EGF比TGFα更能促进绵羊卵母细胞胞质的成熟。
The effects of TGFα and EGF on nuclear and cytoplasm maturation of ovine oocytes cultured in basical medium + BSA, serum, BSA+EGF and BSA+TGFct respectively were investigated by immunofluorescence and orcein staining. The results showed that the maturation rate of oocyte cultured in the four medium as above after 22 hours were 63.5%, 75.2%, 73.1%, 69.8% and the rates of oocytes stayed at telophase of meiosis I were 27.0%, 16.3%, 15.9%, 16.9%, respectively. Supplement of serum, EGF or TGFα significantly enhanced the maturation rates of the oocytes and reduced the rate of oocyte stayed at telophase of meiosis I (P〈0.05); Significant higher rates of normal distribution of α-tubulin in oocytes cultured in serum, BSA+EGF and BSA+TGFα (66.6%, 66.6%, 73.6%) were compared to BSA group (43.3%) (P〈0.05); The rates of oocyte with cortical granules in cortex were 33.9%, 58.8%, 54.7%, 47.9%, respectively, there was significant difference between oocytes cultured with serum, EGF and BSA (P〈0.05). In conclusion, TGFα and EGF can promote the oocyte nuclear transition from telophase I to metaphase of meiosis Ⅱ, and could substitute some substance in serum to improve the quality of oocyte matured in vitro, but EGF might be more functional than TGFα to promote the maturation of ovine ooplasm.