In the present work, we chose a series of DRM-resident proteins to investigate their localization in sperm. These proteins were not restricted to one sperm region but were distributed among different sperm compartments; our findings regarding localization of these proteins are illustrated in Figure  7 . Some of these molecules (e.g., CAV2, GM3, IZUMO, and FLOT2) change their localization during the acrosome reaction. While CAV2 and GM3 appear to be lost, IZUMO and FLOT2 show a different pattern of localization in a fraction of the capacitated sperm population. The new patterns were found only in acrosome-reacted sperm, suggesting that the changes were due not to capacitation but to the acrosome reaction.