牛卵泡液对牛卵母细胞体外成熟的影响

EFFECTS OF BOVINE FOLLICULAR FLUID ON THE IN VITRO MATURATION OF BOVINE OOCYTES

本研究系统探讨了牛卵泡液（ＢＦＦ）对牛卵母细胞体外成熟的影响。在成熟培养液中添加１０％的ＢＦＦ，明显提高牛卵母细胞体外成熟后的囊胚发育率（４５．１％比２８．２％，Ｐ＜０．０５），虽然该处理对牛卵母细胞体外成熟后的受精分裂率无明显影响（８７．５％比８７．５％）。然而，当ＢＦＦ在成熟培养液中的浓度提高到４０％时，卵母细胞体外成熟后的受精分裂率（６８．６％）和囊胚发育率（１６．６％）均明显下降（Ｐ＜０．０５）。来自不同大小卵泡（２～５ｍｍ，５．１～８ｍｍ和大于８ｍｍ）ＢＦＦ的卵母细胞体外成熟培养效果无明显差异，只是来自大于８ｍｍ卵泡的ＢＦＦ将卵母细胞粘在一起，明显地降低成熟培养后的可用卵母细胞数。在成熟培养液中加入激素（２．５×１０３ｉｕ／Ｌ促性腺激素（ＨＣＧ），５０ｉｕ／Ｌ促乳素，０．０５ｍｇ／Ｌ胰岛素、睾酮和雌二醇）对ＢＦＦ的卵母细胞成熟培养效果无影响。这些结果表明，在成熟培养液中添加一定浓度的ＢＦＦ可促进牛卵母细胞获得胚胎发育能力，ＢＦＦ的这一作用与其来源的卵泡大小和激素的存在与否无关。

This study was undertaken to examine the effect of bovine follicular fluid (BFF) on the in vitro maturation of bovine oocytes. The supplementation of 10% BFF to the maturation medium resulted more bovine oocytes developed to the blastocyst stage (P <0. 05 ) in comparison with the oocytes matured in TCM-199 alone or TCM-199 plus 10% oestrous cow serum (45. 1% vs 28. 2% ), although the cleavage rate of oocytes was unaffected by this treatment (87. 5% vs 87. 5%, P>0. 05). However, when the proportion of BFF in the maturation medium was increased to 40%, the cleavage rate and blastocyst development rate of oocytes were decreased significantly (68. 6% and 16. 6%, P< 0. 05).There was no significant difference in the frequency of oocytes undergoing either cleavage or development to the blastocyst stage among the groups treated with BFF from follicles of different sizes,but BFF from follicles above 8 mm in diameter led to the adhesion of oocytes that reduced the number of oocytes that were suitable for IVF. The addition of hormones(2. 5 X 103 in/L HCG, 50 in/L prolatin, 0. 05 mg/L insulin, testosterone and estradiol) to the maturation medium did not affect the positive effect of BFF on the in vitro maturation of bovine oocytes.In conclusion, supplementation of a certain proportion of BFF to the maturation medium can facilitate the acquisition of developmental competence by bovine oocytes during maturation, and this action of BFF is independent of the presence of hormones and the size of follicles from which BFF is collected.