Eppig J J, O'Brien M J, Pendola F L, Watanabe S
The Jackson Laboratory, Bar Harbor, Maine 04609-1500, USA.
Biol Reprod. 1998 Dec;59(6):1445-53. doi: 10.1095/biolreprod59.6.1445.
This study was undertaken to test the hypothesis that FSH treatment of cultured oocyte-granulosa cell complexes promotes acquisition of competence to complete preimplantation embryo development. Oocyte-granulosa cell complexes were isolated from the preantral follicles of 12-day-old mice and cultured for 10 days in serum-free medium, supplemented with insulin (5 microgram/ml), transferrin (5 microgram/ml), and selenium (5 ng/ml) and containing a highly potent preparation of FSH (0-5 ng/ml). Oocytes were matured and fertilized in vitro and embryos cultured to determine the frequency of development to the blastocyst stage. There was no effect of FSH on oocyte size, general morphology, or competence to resume meiosis. However, addition of FSH to medium containing insulin had a deleterious effect on the percentage of mature oocytes competent to develop to the blastocyst stage. Deletion of insulin from the medium for culture of oocyte-granulosa cell complexes prevented the deleterious effect of FSH, but FSH still did not promote acquisition of competence to complete preimplantation development. Culture of oocyte-granulosa cell complexes with FSH resulted in elevated expression of LH receptor (LHR) mRNA by granulosa cells and stimulated the production of functional LHRs, whether or not insulin was present. However, FSH-induced expression of LHR mRNA reached a maximum steady-state level by 4 days of culture in the presence of insulin, but this level was not reached until 10 days of culture without insulin. Granulosa cells encompassing growing mouse oocytes in vivo do not express LHR mRNA. Thus, expression of LHR mRNA by granulosa cells closely associated with growing oocytes in vitro indicates inappropriate or ambiguous development. In conclusion, conditions occurring during oocyte growth can have profound detrimental effects on oocyte developmental competence to complete preimplantation development, even when oocyte growth, general morphology, and competence to resume meiosis appear unaffected.
对培养的卵母细胞 - 颗粒细胞复合体进行促卵泡激素（FSH）处理可促进其获得完成植入前胚胎发育的能力。从12日龄小鼠的窦前卵泡中分离出卵母细胞 - 颗粒细胞复合体，并在无血清培养基中培养10天，该培养基添加了胰岛素（5微克/毫升）、转铁蛋白（5微克/毫升）和硒（5纳克/毫升），并含有高效的FSH制剂（0 - 5纳克/毫升）。卵母细胞在体外成熟并受精，然后培养胚胎以确定发育至囊胚阶段的频率。FSH对卵母细胞大小、一般形态或恢复减数分裂的能力没有影响。然而，在含有胰岛素的培养基中添加FSH对有能力发育至囊胚阶段的成熟卵母细胞百分比有有害影响。从用于培养卵母细胞 - 颗粒细胞复合体的培养基中去除胰岛素可防止FSH的有害作用，但FSH仍未促进获得完成植入前发育的能力。无论是否存在胰岛素，用FSH培养卵母细胞 - 颗粒细胞复合体都会导致颗粒细胞中促黄体生成素受体（LHR）mRNA表达升高，并刺激功能性LHR的产生。然而，在有胰岛素存在的情况下，培养4天时FSH诱导的LHR mRNA表达达到最大稳态水平，但在没有胰岛素的情况下，直到培养10天才达到该水平。在体内围绕生长中的小鼠卵母细胞的颗粒细胞不表达LHR mRNA。因此，在体外与生长中的卵母细胞紧密相关的颗粒细胞中LHR mRNA的表达表明发育不当或不明确。总之，卵母细胞生长期间出现的条件可能对卵母细胞完成植入前发育的发育能力产生深远的有害影响，即使卵母细胞生长、一般形态和恢复减数分裂的能力似乎未受影响。
