TCF21+ mesenchymal cells contribute to testis somatic cell development, homeostasis, and regeneration in mice

Abstract Testicular development and function rely on interactions between somatic cells the germline, but similar to other organs, regenerative capacity declines in aging disease. Whether adult testis maintains a reserve progenitor population remains uncertain. Here, we characterize recently identified mouse interstitial expressing transcription factor Tcf21. We found that TCF21 lin are bipotential progenitors present fetal ovary, maintain homeostasis during aging, act as potential following injury. In vitro, multipotent mesenchymal which form multiple lineages including Leydig myoid cells. Additionally, + resemble resident fibroblast populations reported organs having roles tissue homeostasis, fibrosis, regeneration. Our findings reveal testis, like can be potentially leveraged of future therapies for hypoandrogenism and/or infertility.