FIG. 5.

Usp2 −/− mice show subtle defects in late stage maturation of spermatids in the testis. A) Shown are representative sections of the testis stained with hematoxylin and eosin and viewed with low (top) or high (bottom) magnification. Note in bottom the abnormal clustering of elongating spermatids (black arrowheads) and the round structures that are most likely multinucleated cells/bodies (white arrowheads). B) Overall normal morphologic appearance of the epididymis. Top panel: low-power magnification of the cauda of the epididymis from Usp2 +/+ or −/− mice. Middle and lower panels: high-power magnifications of the cauda from Usp2 +/+ or −/− mice. Arrowheads indicate, in the Usp2 −/−, probable multinucleated cells derived from aberrant maturation of elongating spermatids. C) Dark field images of epididymal spermatozoa from Usp2 +/+ or −/− mice. No evident differences seen. Original magnifications are as follows: For A, ×10 (top), ×40 (middle), and ×100 (bottom); for B, ×10 (top), ×40 (middle), and ×100 (bottom); and for C, ×40.