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Treatment of Starfish Sperm with Egg Jelly Induces the Degradation of Histones
Author(s) -
Amano Tosikazu,
Okita Yoshihito,
Hoshi Motonori
Publication year - 1992
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1992.00099.x
Subject(s) - acrosome reaction , nigericin , histone , monensin , chemistry , sperm , biochemistry , microbiology and biotechnology , biophysics , starfish , biology , botany , ecology , membrane , gene
When spermatozoa of Asterina pectinifera are treated with a solution of homologous egg jelly, besides undergoing the acrosome reaction, they begin to degrade their histones gradually. The degradation is most prominent with histone H1, almost 75% of which is degraded within one hour at 20°C. The jelly‐induced histone degradation, like the acrosome reaction, requires external Ca 2+ , prefers high pHs and is susceptible to Ca 2+ ‐channel antagonists such as verapamil and diltiazem. Histone degradation is also induced by nigericin as well as monensin in normal seawater, but not in Ca 2+ ‐free seawater. Calcium ionophore A23187, that greatly facilitates the monensin‐induced histone degradation, also induces histone degradation by itself, slightly in normal seawater and markedly in Ca 2+ ‐enriched seawater. Concanavalin A inhibits the jelly‐induced histone degradation but not the jelly‐induced acrosome reaction. These results suggest that egg jelly induces the histone degradation by enhancing Ca 2+ ‐influx via a Ca 2+ ‐channel(s) and by increasing cytoplasmic pH, through a pathway which is closely related to, but not entirely the same as, the one leading to the acrosome reaction.