Recently we reported that mouse germ cells in the testis contain active P450 aromatase (P450arom), the enzyme that converts androgens to estrogens. This finding suggested that germ cells have the ability to produce estrogen. Further studies have shown that germ cells in the testis of several species contain P450arom. The goal of this study was to determine if epididymal sperm contain P450arom a...

The human sperm head vacuoles and their role in male infertility are still poorly understood. The aim of this study was to identify the clinical and ultrastructural features of human sperm head vacuoles in men included in the in vitro fertilization programme: men with normal (normozoospermia) and impaired sperm morphology (teratozoospermia). The sperm samples were observed under 6000-time magni...

In nematode, sperm activation (or spermiogenesis), a process in which the symmetric and non-motile spermatids transform into polarized and crawling spermatozoa, is critical for sperm cells to acquire fertilizing competence. SPE-8 dependent and SPE-8 independent pathways function redundantly during sperm activation in both males and hermaphrodites of Caenorhabditis elegans. However, the downstre...

When under competition for fertilisations, males are thought to increase their reproductive success by releasing as many sperm as possible into the reproductive arena and in many species, this prediction holds. For marine invertebrates, which utilise the ancestral strategy of broadcast spawning eggs and sperm, however, it appears that males tend to release their sperm more slowly than females r...

BACKGROUND Curcumin has shown to affect sperm motility and function in vitro and fertility in vivo. The molecular mechanism(s) by which curcumin affects sperm motility has not been delineated. Since modulation of intracellular pH (pHi) and plasma membrane polarization is involved in sperm motility, the present study was conducted to investigate the effect of curcumin on these sperm (human and m...

We explored the relationship between sperm chromatin integrity, hormone levels, seminal plasma total antioxidant capacity (TAC), and routine sperm parameters in men with male factor (MF, n = 81) and non-male factor (NMF, n = 52) infertility. Semen and blood were collected and examined from men undergoing evaluation for infertility in the Avicenna Infertility Clinic. We have examined each patien...

While sperm competition risk favours males transferring many sperm to secure fertilizations, females of a variety of species actively reduce sperm numbers reaching their reproductive tract, e.g. by extrusion or killing. Potential benefits of spermicide to females include nutritional gains, influence over sperm storage and paternity, and the elimination of sperm bearing somatic mutations that wo...

Understanding why there is extensive variation in sperm form and function across taxa has been a challenge because sperm are specialized cells operating at a microscopic level in a complex environment. This comparative study collates published data to determine whether the evolution of sperm morphometry (sperm total length and separate component dimensions) is associated with sperm competition ...

BACKGROUND There is a discrepancy between the use of terminology employed by clinicians and basic scientists concerning the cytoplasmic droplets of sperm. Most clinicians consider their presence on sperm to be indicative of abnormal sperm, whereas basic scientists consider them to be attributes of normal sperm. METHODS The presence of cytoplasmic droplets on human sperm was examined using con...

This study aimed to explore the association between body mass index (BMI), other anthropometric indexes and semen quality in a general male population in Taiwan. In this cross-sectional cohort study, the study cohort consisted of 7941 healthy male individuals aged 18 years or older who participated in a standard medical screening program run by a private firm from January 2008 to May 2013. Seme...