Establishment of the steroid-producing Leydig cell lineage is an event downstream of Sry that is critical for masculinization of mammalian embryos. Neither the origin of fetal Leydig cell precursors nor the signaling pathway that specifies the Leydig cell lineage is known. Based on the sex-specific expression patterns of Desert Hedgehog (Dhh) and its receptor Patched 1 (Ptch1) in XY gonads, we ...

Hybridization between a mouse Leydig tumor cell line, MA-10, which produces cyclic AMP and progesterone under human chorionic gonadotropin (hCG) stimulation, and freshly isolated mouse Leydig cells gave rise to 54 hybrid clones, one of which, LK17, was capable of hCG-stimulated testosterone production. Subcloning of this hybrid resulted in the emergence of a subclone, K9, whose testosterone pro...

A review of the literature indicates that some compounds which produce hepatic peroxisome proliferation in rats also appear to produce Leydig cell adenomas, and some also affect the serum concentrations of testosterone and estradiol. Previous studies with the peroxisome proliferator ammonium perfluorooctanoate showed a direct effect on Leydig cells to alter steroidogenesis. It was therefore pro...