Inactivation of the IGF-I receptor gene in primary Sertoli cells IG

ran ie de ctio physiology, we established a system for Cre-mediated con- contributes significantly to Sertoli cell homeostasis. The (FSH; McLachlan et al. 2002), and by a network of factors originating from both the different somatic cells of the testis acting on, testicular cells, knockout models or spontaneous factors (such as IGF-I, TGF-b) may be expressed by several cell types in the testis and their role can change during and/or quantity could result from Sertoli cell dysfunction. 557Journal of Endocrinology (2007) 194, 557–568genetic defects have allowed us to understand their role on the early steps of spermatogenesis (e.g. stem cell factor (SCF), IGF-I, a pleiotropic cytokine, stimulates metabolism, proliferation, differentiation, and survival of numerous cell DOI: 10.1677/JOE-07-0258(Sertoli cells, Leydig cells, and peritubular cells) and the ger