Why dominant males experiencing intense sperm competition sometimes show low investments in sperm production is not always obvious. One well-documented example is that of the external fertilizing teleost, the Arctic charr (Salvelinus alpinus), where individuals becoming dominant reduce sperm production and sperm swimming speed in water compared to subordinates. Here, we report how ovarian fluid...

Sperm competition, in which the ejaculates of multiple males compete to fertilize a female's ova, results in strong selection on sperm traits. Although sperm size and swimming velocity are known to independently affect fertilization success in certain species, exploring the relationship between sperm length, swimming velocity and fertilization success still remains a challenge. Here, we use the...

BACKGROUND In human fertilization, sperm centrosome function is essential for male and female pronuclear movement and fusion. In this study, we investigated the possibility of restoring human sperm centrosomal function in sperm exhibiting abnormalities in microtubule organization. METHODS Semen was obtained from both a fertile donor and a patient with dysplasia of the fibrous sheath (DFS). Fo...

Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may ...

It is thought that differences in conception rate between feline epididymal sperm and ejaculate sperm occur because, unlike ejaculated sperm, caudal epididymal sperm have not been sensitized with seminal plasma (SP). In this study, we investigated whether collection of feline epididymal sperm with SP influences sperm qualities after freezing-thawing. Sperm were sensitized with SP for 10 min at ...

BACKGROUND DNA adducts are widely used marker of DNA damage induced by environmental pollutants. The present study was designed to explore whether sperm polycyclic aromatic hydrocarbon-DNA adducts were associated with sperm DNA integrity and semen quality. METHODS A total of 433 Han Chinese men were recruited from an infertility clinic. Immunofluorescence was applied to analyze sperm PAH-DNA ...

Sperm competition favors increases in relative testes mass and production efficiency, and changes in sperm phenotype that result in faster swimming speeds. However, little is known about its effects on traits that contribute to determine the quality of a whole ejaculate (i.e., proportion of motile, viable, morphologically normal and acrosome intact sperm) and that are key determinants of fertil...

the presence of anti-sperm antibodies (asa) in semen or serum may impair sperm function leading to immunological infertility. the aim of this study was to investigate the presence of asa on the surface of sperm and in circulating blood of infertile couples. in this cross sectional study, we studied 49 couples suffering from infertility for at least one year. serum asa (igg and iga classes) was ...

Endogenous membrane and cytosolic and nuclear protein phosphorylations were compared among three well-characterized subpopulations of human colonic carcinoma cells that were originally isolated from a single human primary colon tumor. These intratumoral subpopulations of cells were found to differ significantly in their biological properties. Analysis of phosphoproteins by two-dimensional elect...