Medina A, Griffond B, Gomot P
Departamento de Biologia Celular, Facultad de Biologia, Sevilla, Spain.
Reprod Nutr Dev (1980). 1988;28(3A):617-23. doi: 10.1051/rnd:19880407.
Hibernating snails (Helix aspersa) were activated by placing them in environmental chambers under either long-day (LD 18:6) or short-day (LD 8:16) lighting conditions. One day after activation all the snails were injected with (3H-thymidine (5 microCi/g wet weight) in order to estimate the duration of spermatogenic phases under long and short-day cycles. Our histological and autoradiographic observations show that long-day cycles have a positive influence on the development of the male cell line, which becomes apparent from the third week of exposure. While in long-day snails labeled spermatozoa were identifiable 28 days after (3H)-thymidine injection, in short-day snails neither labeled spermatozoa nor spermatids were present in the gonads of animals killed as late as 39 days post-injection. These data strongly suggest that the photoperiod, besides acting on spermatogonial proliferation (Sokolove et al., 1983; Gomot and Griffond, 1987), has an important effect on the second meiotic division. In the course of spermatogenesis in Helix aspersa, the step from secondary spermatocyte to spermatid is probably the most sensitive to environmental factors.
将冬眠的蜗牛（散大蜗牛）置于环境箱中，分别在长日照（光照周期为18小时光照：6小时黑暗，LD 18:6）或短日照（光照周期为8小时光照：16小时黑暗，LD 8:16）条件下使其苏醒。苏醒一天后，给所有蜗牛注射³H-胸腺嘧啶核苷（5微居里/克湿重），以估计长日照和短日照周期下精子发生各阶段的持续时间。我们的组织学和放射自显影观察表明，长日照周期对雄性细胞系的发育有积极影响，从暴露的第三周开始这种影响就很明显。在注射³H-胸腺嘧啶核苷28天后，长日照蜗牛中可识别出标记的精子，而在短日照蜗牛中，直到注射后39天处死的动物性腺中，既没有标记的精子也没有精子细胞。这些数据有力地表明，光周期除了作用于精原细胞增殖（索科洛夫等人，1983年；戈莫和格里丰，1987年）外，对第二次减数分裂也有重要影响。在散大蜗牛的精子发生过程中，从次级精母细胞到精子细胞的阶段可能对环境因素最为敏感。
