Premium
F‐actin in guinea pig spermatozoa: Its role in calmodulin translocation during acrosome reaction
Author(s) -
MorenoFierros Leticia,
Hernández Enrique Othon,
Salgado Zaira O.,
Mújica Adela
Publication year - 1992
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.1080330209
Subject(s) - biology , calmodulin , acrosome , actin , acrosome reaction , cytochalasin , cytochalasin d , microbiology and biotechnology , polyclonal antibodies , phalloidin , cytoskeleton , sperm , biochemistry , antibody , immunology , cell , genetics , enzyme
The presence of actin has been determined in mammalian spermatozoa. However, its function in these cells is still almost unknown. Only in boar spermatozoa has evidence for F‐actin and a possible function for it been presented. In this work, actin distribution and F‐actin were determined in uncapacitated, capacitated, and acrosomal‐reacted guinea pig spermatozoa, by means of monoclonal and polyclonal antibodies, using an indirect immunoperoxidase technique, and by the use of rhodamine‐phalloidin. With the last probe we found filamentous actin in these cells. By both techniques, actin was detected in the acrosome and in the entire tail. In some cells with acrosomal reaction, actin was also detected in the equatorial and in the postacrosomal regions. SDS‐PAGE and Western blots immunostained with monoclonal and polyclonal anti‐actin antibodies confirmed the presence of actin in extracts of guinea pig spermatozoa. Actin was also detected in preparations of Percoll‐purified spermatozoa. We have communicated that guinea pig spermatozoa show a change on calmodulin location during the acrosome reaction. They present it first in the equatorial region and later in the postacrosomal region. To determine if F‐actin participates in this calmodulin translocation, we studied the effect of cytochalasin D. It was found that the number of cells with calmodulin in the equatorial region increased in the presence of cytochalasin D while the number of cells with calmodulin in the postacrosomal region decreased. We also found that after cytochalasin D treatment acrosome loss was increased and sperm motility was slightly inhibited. Our results suggest that actin participate in calmodulin translocation to the postacrosomal region during acrosome reaction, in maintaining the acrosome structure, and perhaps also in sperm motility. © 1992 Wiley‐Liss, Inc.