Abé S, Asakura S, Ukeshima A
Department of Biology, Faculty of Science, Kumamoto University, Japan.
J Exp Zool. 1988 Apr;246(1):65-70. doi: 10.1002/jez.1402460109.
In cell culture, single motile flagella, 1 micron in length, were observed to grow from secondary spermatocytes of Xenopus laevis within 2-3 hours after telophase I, at 22 degrees C. About 90% of the secondary spermatocytes formed flagella as observed by phase-contrast microscopy. The flagella grew up to 2-6 microns in length during interphase II, which lasted about 18 hours. The presence of the "9 + 2" microtubular structure of the flagellar axonemes of secondary spermatocytes was confirmed by electron microscopy. When chromosomal condensation began (prophase II), the flagella were resorbed into the cells and, after the second meiotic division, a flagellum was formed again by each of the round spermatids. Thus, there appears to be a close relationship between the meiotic division cycle and the formation of flagella. The possible contribution of Sertoli cells to the formation of flagella in secondary spermatocytes was examined by reducing the number of Sertoli cells to less than ten per culture. Under these conditions, flagella formed in secondary spermatocytes with very high efficiency. It is very likely that secondary spermatocytes form flagella in vivo, since the secondary spermatocytes were observed to have flagella immediately after dissociation of the testes.
在细胞培养中，在22摄氏度下，观察到从非洲爪蟾的次级精母细胞在第一次减数分裂末期后2至3小时内长出长度为1微米的单个能动鞭毛。通过相差显微镜观察，约90%的次级精母细胞形成了鞭毛。在持续约18小时的第二次减数分裂间期，鞭毛长度增长至2至6微米。通过电子显微镜证实了次级精母细胞鞭毛轴丝存在“9 + 2”微管结构。当染色体开始浓缩（减数分裂前期II）时，鞭毛被吸收回细胞内，并且在第二次减数分裂后，每个圆形精子细胞再次形成一根鞭毛。因此，减数分裂周期与鞭毛形成之间似乎存在密切关系。通过将支持细胞数量减少到每培养物少于十个，研究了支持细胞对次级精母细胞中鞭毛形成的可能贡献。在这些条件下，次级精母细胞中鞭毛形成效率非常高。很可能次级精母细胞在体内形成鞭毛，因为在睾丸解离后立即观察到次级精母细胞具有鞭毛。
