Acrosome reaction of spermatozoa in the Chinese mitten crab, Eriocheir sinensis (Decapoda, Grapsidae): induced by anti-spermatozoal membrane proteins antiserum.

摘要

Three kinds of spermatozoal proteins, i.e., spermatophore matrix proteins, spermatozoal membrane proteins (SMPs), and proteins released during the acrosome reaction (AR), were extracted from good quality fresh spermatozoa of the Chinese mitten crab, Eriocheir sinensis (Decapoda, Grapsidae) and used to immunize three groups of ICR (Institute of Cancer Research) female mice to yield the respective antisera. Incubations of spermatozoa with or without the antisera obtained, were carried out in order to evaluate their effects on the acrosomal status and AR percentage. The results show that the anti-spermatophore matrix proteins antiserum, control serum, or Ca2+-free artificial seawater, all failed to induce AR, and the anti-proteins released during AR antiserum only just induced an AR of 4.7%. In contrast, there was a score of more than 90% AR in spermatozoa incubated with the anti-SMPs antiserum, which presented all four steps of AR in about 1.5 h, and an extremely significant difference in the AR percentages (P<0.01) between the anti-SMPs antiserum and other media. These results demonstrate that, on the spermatozoal membrane, there is/are a/some protein(s) inhibiting AR. AR may occur when the protein(s) is/are combined and blocked by its/their antiserum. In addition, the discovery that the anti-SMPs antiserum activates spermatozoa represents a novel, efficient, and operational method for inducing AR in E. sinensis.