The arrangement of immature germ cells changes regularly and periodically along the axis of the seminiferous tubule, and is used to describe the progression of spermatogenesis. This description is based primarily on the changes in the acrosome and the nuclear morphology of haploid spermatids. However, such criteria cannot be applied under pathological conditions with arrested spermatid differentiation. In such settings, the changes associated with the differentiation of premeiotic germ cells must be analyzed. Here, we found that the unique bipolar motor protein, KIF11 (kinesin-5/Eg5), which functions in spindle formation during mitosis and meiosis in oocytes and early embryos, is expressed in premeiotic germ cells (spermatogonia and spermatocytes). Thus, we aimed to investigate whether KIF11 could be used to describe the progression of incomplete spermatogenesis. Interestingly, KIF11 expression was barely observed in haploid spermatids and Sertoli cells. The KIF11 staining allowed us to evaluate the progression of meiotic processes, by providing the time axis of spindle formation in both normal and spermatogenesis-arrested mutant mice. Accordingly, KIF11 has the potential to serve as an excellent marker to describe spermatogenesis, even in the absence of spermatid development.

未成熟生殖细胞的排列沿着生精小管的轴定期且周期性地变化，并用于描述精子发生的进程。该描述主要基于单倍体精子的顶体和核形态的变化。但是，这种标准不能在精子细胞分化停止的病理条件下应用。在这种情况下，必须分析与减数分裂前生殖细胞分化有关的变化。在这里，我们发现独特的双极运动蛋白KIF11（驱动蛋白5 / Eg5）在卵母细胞和早期胚胎的有丝分裂和减数分裂过程中在纺锤体形成中起作用，并在减数分裂前的生殖细胞（精原细胞和精细胞）中表达。因此，我们旨在研究KIF11是否可用于描述不完全精子发生的进展。有趣的是，在单倍体精子细胞和Sertoli细胞中几乎未观察到KIF11表达。KIF11染色使我们能够通过提供正常和精子发生停止的突变小鼠中纺锤体形成的时间轴来评估减数分裂过程的进展。因此，即使在没有精子细胞发育的情况下，KIF11也有可能成为描述精子发生的优秀标记。