Abstract：
Spermatogenesis is a continual process that relies on the activities of undifferentiated spermatogonia, which contain spermatogonial stem cells (SSCs) that serve as the basis of spermatogenesis. The gene expression pattern and molecular control of fate decisions of undifferentiated spermatogonia are not well understood. Rho guanine nucleotide exchange factor 15 (ARHGEF15, also known as EPHEXIN5) is a guanine nucleotide-exchange factor (GEF) that activates the Rho protein. Here, we reported that ARHGEF15 was expressed in undifferentiated spermatogonia and spermatocytes in mouse testes; however, its deletion did not affect spermatogenesis. Arhgef15-/- mice were fertile, and histological examination of the seminiferous tubules of Arhgef15-/- mice revealed complete spermatogenesis with the presence of all types of spermatogenic cells. Proliferation and differentiation of the undifferentiated spermatogonia were not impacted; however, further analysis showed that Arhgef15 deletion resulted in decreased expression of Nanos2, Lin28a and Ddx4. Together, these findings suggest that ARHGEF15 was specifically enriched in undifferentiated spermatogonia and regulated gene expression but dispensable for spermatogenesis in mice.
摘要：
精子发生是一个持续的过程，依赖于未分化的精原细胞的活动，其中含有精原干细胞（SSC），作为精子发生的基础。未分化精原细胞命运决定的基因表达模式和分子控制尚不清楚。Rho鸟嘌呤核苷酸交换因子15（ARHGEF15，也称为EPHEXIN5）是激活Rho蛋白的鸟嘌呤核苷酸交换因子（GEF）。这里,我们报道ARHGEF15在小鼠睾丸的未分化精原细胞和精母细胞中表达;其缺失不影响精子发生。Arhgef15-/-小鼠可育，Arhgef15-/-小鼠的生精小管的组织学检查显示，所有类型的生精细胞都存在，精子发生完全。未分化精原细胞的增殖和分化不受影响；然而，进一步分析显示Arhgef15缺失导致Nanos2、Lin28a和Ddx4的表达降低。一起,这些发现表明ARHGEF15在未分化的精原细胞中特异性富集并调节基因表达,但对小鼠精子发生没有影响.
