Haploid male gametes are produced through meiosis during gametogenesis. Whereas the cell biology of mitosis and meiosis is well studied in the nematode Caenorhabditis elegans, comparatively little is known regarding the physical division of primary spermatocytes during meiosis I. Here, we investigated this process using high-resolution time-lapse confocal microscopy and examined the spatiotemporal regulation of contractile ring assembly in C. elegans primary spermatocytes. We found that centralspindlin and RhoA effectors were recruited to the equatorial cortex of dividing primary spermatocytes for contractile ring assembly before segregation of homologous chromosomes. We also observed that perturbations shown to promote centralspindlin oligomerization regulated the cortical recruitment of NMY-2 and impacted the order in which primary spermatocytes along the proximal–distal axis of the gonad enter meiosis I. These results expand our understanding of the cellular division of primary spermatocytes into secondary spermatocytes during meiosis I.

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单倍体雄性配子是在配子发生过程中通过减数分裂产生的。虽然有丝分裂和减数分裂的细胞生物学在秀丽隐杆线虫中得到了很好的研究，但对于减数分裂 I 期间初级精母细胞的物理分裂知之甚少。在这里，我们使用高分辨率延时共聚焦显微镜研究了这一过程并检查了秀丽隐杆线虫收缩环组装的时空调控初级精母细胞。我们发现，在分离同源染色体之前，中央纺锤体和 RhoA 效应器被招募到分裂初级精母细胞的赤道皮层进行收缩环组装。我们还观察到，促进中央纺锤体寡聚化的扰动调节了 NMY-2 的皮质募集，并影响了初级精母细胞沿性腺近端 - 远端轴进入减数分裂 I 的顺序。这些结果扩展了我们对初级细胞分裂的理解。减数分裂过程中精母细胞变为次级精母细胞 I。

本文与论文的第一作者进行了相关的第一人称采访。