We have developed an assay for detecting the acrosome reaction in mouse sperm using chlortetracycline (CTC) as a fluorescent probe . Sperm known to be intact with nonreacted acrosomes show CTC fluorescence in the presence of Ca" over the anterior portion of the sperm head on the plasma membrane covering the acrosome . Sperm which have undergone the acrosome reaction do not show fluorescence on ...

Theory predicts that males experiencing elevated levels of sperm competition will invest more in gonads and produce faster-swimming sperm. Although there is ample evidence in support of the first prediction, few studies have examined sperm swimming speed in relation to sperm competition. In this study, we tested these predictions from sperm competition theory by examining sperm characteristics ...

Recently, the conception rates after artificial insemination have been pointed out to decline continuously. To overcome this problem, the control of frozen and thawed sperm quality is required. However, the mechanism of bovine sperm functional regulation is still largely unknown. In mammals, the ejaculated sperm are capable of showing fertilizing ability during migration in the female reproduct...

The objective of this study was to compare (i) the intracytoplasmic sperm injection outcomes among groups with different total motile sperm count ranges, (ii) the intracytoplasmic sperm injection outcomes between groups with normal and abnormal total motile sperm count, and (iii) the predictive values of WHO 2010 cut-off values and pre-wash total motile sperm count for the intracytoplasmic sper...

Sperm morphology evolves rapidly, resulting in an exceptional diversity of sperm size and shape across animal phyla. This swift evolution has been thought to prevent fertilizations between closely related species. Alternatively, recent correlative analyses suggest that competition among sperm from more than one male may cause sperm diversity, but these hypotheses have not been tested. Here, we ...

We consider oscillator ensembles consisting of subpopulations of identical units, with a general heterogeneous coupling between subpopulations. Using the Watanabe-Strogatz ansatz, we reduce the dynamics of the ensemble to a relatively small number of dynamical variables plus constants of motion. This reduction is independent of the sizes of subpopulations and remains valid in the thermodynamic ...

Interspecific comparative studies have shown that, in most taxa, postcopulatory sexual selection (PCSS) in the form of sperm competition drives the evolution of longer and faster swimming sperm. Work on passserine birds has revealed that PCSS also reduces variation in sperm size between males at the intraspecific level. However, the influence of PCSS upon intra-male sperm size diversity is poor...

This study investigated the relationship between acrosin activation and pig sperm proacrosin binding protein (sp32) phosphorylation levels. Differently processed pig spermatozoa (fresh semen sperm, capacitation sperm, acrosome reaction sperm, capacitation-like sperm, and thawed sperm) were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot analysis. The fres...

The sperm quality index (SQI) and sperm mobility index (SMI) both predict sperm motility. Previous research was conducted comparing the SMI with the SQI; however, semen was diluted improperly for the SQI (40-fold). For an accurate comparison, semen must be diluted 10-fold for the SQI. Therefore, the overall objective of this study, utilizing 4 experiments, was to examine the relationship of the...

Most publications devoted to the cryopreservation of mollusc sperm have focused on the definition of technical protocols, avoiding the description of sperm quality after thawing. The present study investigated the effects of cryopreservation on sperm quality in the great scallop. Wild scallop were fished during the natural spawning period and conditioned in the hatchery before use. Sperm sample...