Loss of sperm in juvenile spermatogonial depletion (jsd) mutant mice is ascribed to a defect of intratubular environment to support germ cell differentiation

Abstract

C57BL/6(B6)‐jsd/jsd mice are sterile due to the defective spermatogenesis in the testes. To know the cause of the deficient spermatogenesis in B6‐jsd/jsd mice, we examined whether the problem is within or outside the seminiferous tubules by transplanting tubules from cryptorchid testes of B6−+/+ mice into B6‐jsd/jsd testes or tubules from B6‐jsd/jsd mice into testes of (WB × C57BL/6)F1‐W/W (hereafter, WBB6F1‐W/W) mice. Type A spermatogonia differentiated into spermatids in seminiferous tubules from cryptorchid testes transplanted into B6‐jsd/jsd testes. In contrast, in B6‐jsd/jsd tubules transplanted into WBB6F1‐W/W testes, type A spermatogonia were stimulated to mitotic proliferation, but didn't proceed to any differentiated germ cells. The present results suggest that the cause of the deficient spermatogenesis in B6‐jsd/jsd mice is a defect of intratubular environment to support germ cell differentiation.