Fig. 2. TLS deficiency is associated with defective spermatogenesis. (A) Photomicrographs of representative sections of mouse testes with the TLS genotype indicated. The arrows in panels 4 and 5 point to degenerating pre-meiotic spermatocytes, and in panels 6 and 7 arrows point to round spermatids that are conspicuously larger in the mutant testes. The asterisks in panel 7 point to deformed elongated spermatids. (B) Photomicrographs of representative sections of newborn mouse testes with the TLS genotype indicated.