Figure 3.

Behavior of golden hamster spermatozoa in fertilization-supporting medium. (A) The flagellar beating pattern of epididymal spermatozoon shortly after release into medium. Note the shallow, symmetrical waves that originate near the head (labeled 1, 2 and 3). Spermatozoa first move freely in the medium, but soon agglutinate head to head, beating their tails stiffly. (B) Two sperm attach to each other by the acrosomal region of the head. (C) A large group of sperm agglutinated head to head. (D, E) After a few hours in capacitation medium, spermatozoa become free from agglutination and swim vigorously, entering the state called “hyperactivation.” Note the deep flagellar bends. (F) When hyperactivated sperm enter a viscous medium or cumulus oophorus, they display a serpentine movement. When they return to nonviscous medium, they resume hyperactivated (“jumping around”) motion (E).