牛小腔前卵泡体外生长发育的研究

 在添加有ITS、丙酮酸钠、次黄嘌呤、血清、FSH、LH、E2的α-MEM基础液中加入表皮生长因子（EGF）和碱性成纤维生长因子(bFGF)及氢化可的松（HC），对直径＜100 ?m（平均直径61～70?m）的牛小腔前卵泡进行体外培养。结果表明，试验I，在FSH、LH、E2浓度分别为0.25 ?g·ml-1、5 iu·ml-1、0.5 ?g·ml-1时，卵泡体外培养7 d， EGF和bFGF联合存在好于分别单独存在时的培养效果，当bFGF（25 ng或50 ng）剂量保持不变，提高EGF含量（25 ng,50 ng）有抑制卵泡发育的作用；增加bFGF的剂量有助于腔前卵泡的发育。 试验II，当FSH、LH、E2分别调整到4 ?g·ml-1、10 iu·ml-1、0.1 ?g·ml-1，并添加了氢化可的松（40 ng·ml-1），卵泡体外培养13 d，在试验3组（EGF 25ng）和试验4组（EGF 25 ng+ bFGF 50 ng），卵泡发育率和卵泡平均增长直径均显著好于试验1组（未添加EGF、bFGF、氢化可的松）和试验2组（只添加氢化可的松）。体外培养第20 d，试验3组和试验4组卵泡发育率分别为15.79 %和25.58 %，卵泡最大增长直径分别为300和320 ?m，并形成小的卵泡腔（成腔率分别为7.69 %和17.65 %），而试验1组和试验2组其卵泡发育率均为0。表明体外培养腔前卵泡时，不同的培养体系对其生长发育有十分重要的影响，各种成分之间存在互作的关系。

Study on in vitro Growth and Development of Bovine Small Preantral Follicles

Bovine small preantral follicles whose diameter <100 μm (61-70 μm in average) were chosen to culture in vitro. EGF, bFGF and hydrocortione were added to α-MEM medium containing ITS, Sodium Pyruvate, and L-Glutamine, hypoxanthine, serum, FSH, LH, E2. The first experiment result showed that the follicles were cultured for 7 days in vitro when the concentration of FSH, LH, E2 were 0.25 μg·ml-1, 5 iu·ml-1, 0.5 μg·ml-1. The development of the follicles when using both EGF and bFGF was better than with EGF or bFGF individually. When the dose of bFGF（25 ng or 50 ng）was kept invariable, the development of the follicles would be inhibited with the increase of the concentration of EGF . If the dose of bFGF was increased, there would be a good development. The second experiment: the concentrations of FSH, LH and E2 were adjusted into 4 μg·ml-1, 10 iu·ml-1, 0.1 μg·ml-1 and hydrocortione (40 ng·ml-1) was added to α-MEM medium. After being cultured for 13 days in vitro, the developmental rates and the average increasement diameter of follicles in both the test group 3 (EGF 25 ng ) and the test group 4 (EGF 25 ng＋bFGF 50 ng) were significantly better than test group 1 (without EGF, bFGF, hydrocortione ) and test group 2 (only added with hydrocortisone). At the 20 day in vitro culture, in both the test group 3 and the test group 4, the ratio of development follicles were 15.79% and 25.58%, and the maximum increase diameter of follicles were 300 μm and 320 μm, and small antrum of follicles came into being (the rates of antrum formation were 7.69 % and 17.65 %, respectively). While in the test group 1 and test group 2, the developmental rate of the follicles was 0. The results showed that when the follicles were cultured in vitro, the variety of culture system had an important influence on the development of preantral follicles, and the components of medium influenced each other.