LncRNA Arsa-DT is required for spermatogenesis and male fertility by regulating G2/M progression.

Male infertility is a major reproductive health burden worldwide, yet its molecular etiology remains largely unknown. The testis expresses numerous long non-coding RNAs (lncRNAs), although their involvement in the pathophysiology of male infertility remains unexplored. Here, we identified Arsa-DT, a testis-predominant divergent lncRNA of Arsa, and demonstrated its essential role in maintaining male fertility. Loss of Arsa-DT leads to subfertility, characterized by reduced sperm production, increased sperm abnormalities, and decreased serum testosterone levels. Notably, Arsa-DT deficiency alters the testosterone-to-estradiol ratio through upregulation of aromatase expression. Specifically expressed in the nuclei of spermatogonia and spermatocytes, Arsa-DT regulates spermatogenesis in the seminiferous tubules. Mechanistically, Arsa-DT regulates G2/M phase progression and chromosome segregation in male germ cells. Collectively, our findings identify Arsa-DT, a testis-predominant lncRNA, as a regulator of spermatogenesis by controlling G2/M phase progression of male germ cells. This study provides mechanistic insights into the pathogenesis of male infertility.