BACKGROUND Human spermatogenesis is regulated by complex networks, and estrogens are recognized as one of the significant regulators of spermatogenesis. We tested the associations between variants of estrogen-related genes and semen parameters. METHODS We performed genotyping for genetic variants of estrogen-related genes and quantitative trait analysis of fertile and infertile men with well-...

Onabotulinumtoxin A (onabotA) is gaining wide medical use in children. The present study was planned to investigate the influence of its injection on the maturing testicular structures in rats. Immature rats were injected in the bilateral cremaster muscles by onabotA with three doses of (10, 20, and 40 U/kg) three times in a 2-week interval. The effect of these injections on fertility indices w...

Along with many of the genome-wide transitions in chromatin composition throughout spermatogenesis, epigenetic modifications on histone tails and DNA are continuously modified to ensure stage specific gene expression in the maturing spermatid. Recent findings have suggested that the repertoire of epigenetic modifications in the mature sperm may have a potential role in the developing embryo and...

Sperm competition appears to be an important aspect of any mating system in which individual female organisms mate with multiple males and store sperm. Post-copulatory sexual selection may be particularly important in species that store sperm throughout long breeding seasons, because the lengthy storage period may permit extensive interactions among rival sperm. Few studies have addressed the p...

Sperm competition has been studied in many gonochoric animals but little is known about its occurrence in simultaneous hermaphrodites, especially in land snails. The reproductive behaviour of the land snail Helix aspersa involves several features, like multiple mating, long-term sperm storage and dart-shooting behaviour, which may promote sperm competition. Cryptic female choice may also occur ...

Activities of total lactate dehydrogenase, which plays an important role in providing energy for cell metabolism, lactate dehydrogenase-X, an isoenzyme of lactate dehydrogenase supposed to be specific for germinal epithelium activity, diluted semen absorbance and some other properties have been measured in 51 seminal plasma samples. Aiming to study its clinical use as a marker of seminiferous e...

Along with many of the genome-wide transitions in chromatin composition throughout spermatogenesis, epigenetic modifications on histone tails and DNA are continuously modified to ensure stage specific gene expression in the maturing spermatid. Recent findings have suggested that the repertoire of epigenetic modifications in the mature sperm may have a potential role in the developing embryo and...