Abstract
At ejaculation, the epididymal spermatozoa mix with the secretions produced by the seminal vesicles and the prostate. The glandular secretions immediately turns into a gel-like structure which entraps the spermatozoa. The ejaculated spermatozoa become progressively motile as the gel dissolves. The discovery, structure, and interactions of proteins involved in these post-ejaculatory phase reactions of semen are here reported.