Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi , Japan.
PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan.
Biol Reprod. 2023 Oct 13;109(4):474-481. doi: 10.1093/biolre/ioad087.
The mammalian epididymis is the organ for functional sperm maturation. In rodents, the initial segment, the most proximal region of the epididymis, plays a critical role in sperm maturation. The luminal epithelial differentiation and the following gene expression of the initial segment are regulated by the lumicrine signaling, a testis-epididymis transluminal secreted signaling. Adhesion G protein-coupled receptor G2 (ADGRG2) is expressed in the efferent duct and the initial segment epididymis. In the preceding study, Adgrg2 ablation decreased the expression of several genes expressed in the initial segment. Such downregulated genes include those known to be regulated by lumicrine signaling, suggesting the involvement of ADGRG2 in lumicrine signaling. The present study examined whether ADGRG2 is associated with the lumicrine signaling regulating epididymal initial segment differentiation and gene expression. Adgrg2-null mice were generated by CRISPR/CAS9-mediated genome editing. The postnatal differentiation of the Adgrg2-null male epididymal initial segment was histologically comparable with that of control wild-type animals. The RNA-seq of Adgrg2-null mice was performed together with those of efferent duct-ligated and W/Wv mice in both of which lumicrine signaling is defective. The comparative transcriptome analyses clarified that the expressions of genes expressed in the initial segment and regulated by lumicrine signaling were decreased by Adgrg2 nullification. However, the extent of such downregulations observed in Adgrg2-null epididymis was not so prominent compared with those of lumicrine signaling deficient Nell2-/-, efferent duct-ligated, or W/Wv mice. Collectively, these findings indicate that ADGRG2 is dispensable for the lumicrine regulation of epididymal initial segment differentiation.
哺乳动物的附睾是精子功能成熟的器官。在啮齿类动物中，附睾的起始段是附睾最近端的区域，在精子成熟过程中起着关键作用。初始段的管腔上皮分化和随后的基因表达受管腔分泌信号的调节，该信号是一种睾丸-附睾管腔分泌的信号。粘附 G 蛋白偶联受体 G2（ADGRG2）在输出小管和附睾初始段表达。在之前的研究中，Adgrg2 缺失降低了几个在初始段表达的基因的表达。这些下调的基因包括已知受管腔分泌信号调节的基因，表明 ADGRG2 参与了管腔分泌信号。本研究旨在研究 ADGRG2 是否与调节附睾初始段分化和基因表达的管腔分泌信号有关。通过 CRISPR/CAS9 介导的基因组编辑生成 Adgrg2 敲除小鼠。Adgrg2 敲除雄性附睾初始段的出生后分化在组织学上与对照野生型动物相似。对 Adgrg2 敲除小鼠进行了 RNA-seq 分析，并与Nell2-/-、输出小管结扎和 W/Wv 小鼠进行了比较，这些小鼠的管腔分泌信号均有缺陷。比较转录组分析表明，Adgrg2 缺失导致初始段表达和受管腔分泌信号调节的基因表达降低。然而，与 Nell2-/-、输出小管结扎或 W/Wv 小鼠相比，Adgrg2 敲除附睾中这些下调的程度并不那么显著。这些发现表明，ADGRG2 对于附睾初始段分化的管腔分泌调节是可有可无的。
