Figure 6.

Expression and localization of HH signaling molecules in the gonads. (A) Role of the DHH signaling in fetal testis’ morphogenesis and differentiation. Schematic presentation of embryonic day 10.5 (E10.5) to E11.5 fetal mouse testis depicting SRY-induced SOX9 expression. SRY and SOX9-induced factors mediate proliferation and differentiation of Sertoli cells (SCs), which express DHH. (B) DHH secreted from the SCs acts on the PTCH and SMO expressed in Leydig cells (LCs) and induce activation of GLI transcription factors. DHH signaling induce steroidogenesis in differentiated LCs. (C) In the ovary, the granulosa cells express IHH/DHH, which act on PTCH-positive TC precursor cells. HH binding to PTCH1 releases SMO, which activate the GLI2 TFs and differentiate the TCs.