Characteristics of sperm from Mll5 +/+ and -/- mice.

aSperm from the both epididymides and vasa deferentia of freshly sacrificed male mice (age 4-6 months) were counted on a haemocytometer to determine the concentrations per mouse, following capacitation (for motility studies) or fixation (for sperm counts).bSperm head morphology was assessed by light microscopy.