Hedgehog Signaling in Gonadal Development and Function.

Three distinct hedgehog (HH) molecules, (sonic, desert, and indian), two HH receptors (PTCH1 and PTCH2), a membrane bound activator (SMO), and downstream three transcription factors (GLI1, GLI2, and GLI3) are the major components of the HH signaling. These signaling molecules were initially identified in . Later, it has been found that the HH system is highly conserved across species and essential for organogenesis.