Gomes J E, Pesty A, Gouveia-Oliveira A, Cidadão A J, Plancha C E, Lefèvre B
Instituto de Histologia e Embriologia, Faculdade de Medicina de Lisboa, Portugal.
Int J Dev Biol. 1999 Nov;43(8):839-42.
The action of gonadotropins upon the oocyte is known to be crucial at later stages of follicular development in mammals. However, its influence on oocytes at early preantral stages is still a matter of debate. In the present study we evaluated the onset of mouse oocyte's capacity to exhibit calcium spikes during preantral stages of follicular development, prior to meiotic competence acquisition. In particular, through the use of confocal microscopy, we probed for the specific effects of age and gonadotropin stimulation upon the calcium dynamics of preantral follicle oocytes. We found that important developmental changes on the Ca2+ signalling mechanisms take place early during follicular development. Specifically we demonstrate that both age and gonadotropin stimulation increase the capacity of oocytes recovered from preantral follicles to exhibit calcium spikes. We propose that a strictly morphological staging of follicular development is insufficient to predict oocyte behaviour and must take in consideration animal age and gonadotropin environment.
已知促性腺激素对卵母细胞的作用在哺乳动物卵泡发育的后期阶段至关重要。然而，其在卵泡早期窦前阶段对卵母细胞的影响仍存在争议。在本研究中，我们评估了小鼠卵母细胞在卵泡发育窦前阶段、获得减数分裂能力之前表现出钙峰的能力的起始情况。特别是，通过使用共聚焦显微镜，我们探究了年龄和促性腺激素刺激对窦前卵泡卵母细胞钙动力学的具体影响。我们发现，在卵泡发育早期，Ca2+信号传导机制发生了重要的发育变化。具体而言，我们证明年龄和促性腺激素刺激均会增加从窦前卵泡中回收的卵母细胞表现出钙峰的能力。我们提出，仅基于卵泡发育的严格形态学分期不足以预测卵母细胞的行为，还必须考虑动物年龄和促性腺激素环境。
