FIG. 6.
Degeneration of elongate spermatids in Bclw-deficient mice. A) Light micrograph showing degeneration of step 13 spermatids (white arrowheads), appearing as very dense material, in seminiferous tubules from a Bclw homozygous mutant. Symplasts of round spermatids (S) were also commonly seen in mutants. ×275. B) Light micrograph showing a comparable stage I tubule in a control animal. Normally developing round (black arrowheads) and elongate (white arrowheads) spermatids are marked. ×170. C) Electron micrograph of a stage VI seminiferous tubule from a Bclw-deficient animal. Step 6 (6) spermatids are associated with a dense, degenerating symplast of step 13 (13) spermatids (lower left) that is contained in a single, dense cytoplasmic mass in contact with Sertoli cells (S). Step 13 spermatid nuclei (n) are indicated. ×3200.