Mehlmann Lisa M, Jones Teresa L Z, Jaffe Laurinda A
Department of Physiology, University of Connecticut Health Center, Farmington, CT 06032, USA.
Science. 2002 Aug 23;297(5585):1343-5. doi: 10.1126/science.1073978.
The mammalian ovarian follicle consists of a multilayered complex of somatic cells that surround the oocyte. A signal from the follicle cells keeps the oocyte cell cycle arrested at prophase of meiosis I until luteinizing hormone from the pituitary acts on the follicle cells to release the arrest, causing meiosis to continue. Here we show that meiotic arrest can be released in mice by microinjecting the oocyte within the follicle with an antibody that inhibits the stimulatory heterotrimeric GTP-binding protein Gs. This indicates that Gs activity in the oocyte is required to maintain meiotic arrest within the ovarian follicle and suggests that the follicle may keep the cell cycle arrested by activating Gs.
哺乳动物的卵巢卵泡由围绕卵母细胞的多层体细胞复合体组成。卵泡细胞发出的信号使卵母细胞的细胞周期停滞在减数分裂I的前期，直到垂体分泌的促黄体生成素作用于卵泡细胞解除停滞，使减数分裂继续进行。在此，我们表明，通过向卵泡内的卵母细胞显微注射一种抑制刺激性异三聚体GTP结合蛋白Gs的抗体，可在小鼠中解除减数分裂停滞。这表明卵母细胞中的Gs活性是维持卵巢卵泡内减数分裂停滞所必需的，并提示卵泡可能通过激活Gs来使细胞周期停滞。
