Fig. 4.

Immunogold localization of MMP2 in bull spermatozoa and spermatid at end of cap phase. a In ejaculated sperm immunogold labeling, utilizing anti-tMMP2 antibody, is found through the apical (AS) and principal segments (PS) of the acrosome, a large portion associated with the IAM. See Suppl. Fig. 1b for preimmune control. Bar 0.2 μm. b In step 7-8 spermatid labeling with anti-pMMP antibody is seen along the inner acrosomal membrane (arrows) of the acrosome. AG acrosomic granule. Bar 0.2 μm