Transcriptional control of male-specific pathway in temperature-dependent sex determination

How temperature affects the direction of sexual differentiation pathways in temperature-dependent sex determination (TSD) remains a mystery despite decades of scientific investigation. In the accompanying study, we demonstrated the thermal switch mechanism within thermosensitive steroidogenic cells (TSSCs) that triggers the male development pathway in turtles (Trachemys scripta elegans). However, the transcriptional regulatory mechanisms linking TSSCs' cold sensitivity with pre-Sertoli cell specification remain elusive. Herein, we elucidate the regulatory schema governing the male determination pathway, including Ca²⁺-induced aldosterone synthesis in TSSCs and subsequent aldosterone-driven transcriptional modulation in pre-supporting cells. Aldosterone-bound NR3C1, a master regulator of the male determination pathway, activates DMRT1 gene expression, culminating in pre-Sertoli specification. Therefore, this study discovers a novel male-specific pathway by which temperature initiates male sex determination in TSD species.