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...

Sperm head morphology has been identified as a characteristic that can be used to predict a male's semen quality. In the present study, we have developed an automated sperm head morphology analysis (ASMA) plug-in for open-source ImageJ software (http://rsbweb.nih.gov/ij/). We describe the plug-in's functionality, and confirm its validity for sperm head morphology analysis using fish sperm. Sper...

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...

introduction: the frequency of sperm pcc indiction in normal and infertile men was investigated. material and methods: zona – free hamster oocyte were retrieved after super ovulation by pmsg and hcg infection. following treatment with hyaloronidase, zona was removed by trypsin digestion. sperms were classified with sperms, and then transferred to fresh media containing colcemid. slides were pre...

The sperm of Nucella are long and threadlike. The fiagellar shaft runs from the acrosome at the front of the head to the tip of the tail. Its anterior portion, the head shaft, is ensheathed by the nucleus. If a suspension of sperm in normal-concentration sea water is observed under phase contrast, and allowed to dry out slowly, the nuclear material of sperm near the edge of the coverglass swell...

The exposure of male mice to radiofrequency radiations from mobile phone (GSM) base stations at a workplace complex and residential quarters caused 39.78 and 46.03%, respectively, in sperm head abnormalities compared to 2.13% in control group. Statistical analysis of sperm head abnormality score showed that there was a significant (p < 0.05) difference in occurrence of sperm head abnormalities ...

On terminally differentiated sperm cells, surface proteins are segregated into distinct surface domains that include the anterior and posterior head domains. We have analyzed the formation of the anterior and posterior head domains of guinea pig sperm in terms of both the timing of protein localization and the mechanism(s) responsible. On testicular sperm, the surface proteins PH-20, PH-30 and ...

This work evaluates sperm head morphometric characteristics in adolescents from 12 to 18 years of age, and the effect of varicocele. Volunteers between 150 and 224 months of age (mean 191, n = 87), who had reached oigarche by 12 years old, were recruited in the area of Barranquilla, Colombia. Morphometric analysis of sperm heads was performed with principal component (PC) and discriminant analy...

Post-copulatory sexual selection in the form of sperm competition is known to influence the evolution of male reproductive proteins in mammals. The relationship between sperm competition and regulatory evolution, however, remains to be explored. Protamines and transition nuclear proteins are involved in the condensation of sperm chromatin and are expected to affect the shape of the sperm head. ...

The sperm cell has a characteristic polarized morphology and its surface is also highly differentiated into different membrane domains. Junctional protein ring structures seal the surface of the mid-piece from the head and the tail respectively and probably prevent random diffusion of membrane molecules over the protein rings. Despite the absence of such lateral diffusion-preventing structures,...