COMPLEX GANGLIOSIDES ARE ESSENTIAL IN SPERMATOGENESIS OF MICE - POSSIBLE ROLES IN THE TRANSPORT OF TESTOSTERONE

Mice, homozygous for disrupted ganglioside GM2/GD2 synthase (EC 2.4.1. 94) gene and lacking all complex gangliosides, do not display any majo r neurologic abnormalities. Further examination of these mutant mice, however, revealed that the males were sterile and aspermatogenic, In t he seminiferous tubules of the mutant mice, a number of multinuclear g iant cells and vacuolated Sertoli cells were observed. The levels of t estosterone in the serum of these mice were very low, although testost erone production equaled that produced in wild-type mice. Testosterone was found to be accumulated in interstitial Leydig cells, and intrate sticularly injected testosterone was poorly drained in seminiferous fl uid in the mutant mice, These results suggested that complex gangliosi des are essential in the transport of testosterone to the seminiferous tubules and bloodstream from Leydig cells. Our results provide insigh ts into roles of gangliosides in vivo.