A single-nucleus transcriptomic atlas of primate testicular aging reveals exhaustion of the spermatogonial stem cell reservoir and loss of Sertoli cell homeostasis

The testis plays a crucial role throughout life in spermatogenesis and production of male sex hormones, pivotal processes in male fertility and multiple physiological functions in men (Oatley and Brinster, 2012; Finkelstein et al., 2013). In aging, spermatogenesis undergoes progressive decline, a leading cause of male infertility that also increases the risk for genetic or other types of abnormalities in offspring (Basaria, 2013). In addition, testicular aging is accompanied by changes in sex hormone metabolism, which may contribute to a series of male reproductive diseases (i.e., late-onset hypogonadism [LOH], erectile dysfunction and so on), reducing quality of life in the elders (Sampson et al., 2007). Therefore, acquiring a comprehensive mechanistic understanding of primate testicular aging remains an outstanding challenge.