Fig. 3.

Schematic illustration of human testicular diseases associated with impairment of Cx43. In physiological situations, Sertoli cell Cx43 independently or dependently of gap junction channels participates in the control of germ cell proliferation, differentiation, survival, and apoptosis required for spermatogenesis. In physiopathological conditions, for example under the influence of genetic, epigenetic and/or environmental factors, a decreased or complete rupture of the control of germ cells by Sertoli cells through Cx43 can conduce either to hypospermatogenesis, which first leads to man hypofertility, or to abnormal tumor cell proliferation, which finally leads to testicular germ cell tumors