FIG. 4.

Abnormal morphology and motility of sperm from Pol λ^−/− mice. (A and B) Analysis of the contents of the cauda epididymis of wild-type (A) and Pol λ^−/− (B) mice at 9 weeks of age. Sperm of Pol λ^−/− mice exhibited shorter and snaggy tails and round-shaped heads. (C) Frequency of motile sperm from Pol λ^+/+, Pol λ^+/−, and Pol λ^−/− mice. (D through G) Histological analysis of seminiferous tubules of 5-week-old wild-type (D and F) and Pol λ^−/− (E and G) mice at low (D and E) and higher (F and G) magnification at stage VIII. No mature spermatids were seen at stage VIII in Pol λ^−/− mice (G). (H and I) Histological analysis of the corpus epididymis of wild-type (H) and Pol λ^−/− (I) mice at 7 weeks of age. The epididymis of Pol λ^−/− mice contains immature sperm with snaggy tails, residual bodies, and basophilic monocuclear cells in the lumen (I).