Following elongation of spermatids in mammals, the histones are replaced by a set of basic nuclear transition proteins; in the rat there are four, named TP1-TP4. Of these, TP1 and TP2 are well characterized. Here we report the purification to homogeneity of TP4 from rat spermatids. It is a low molecular mass (about 13-20 kDa) basic protein with arginine and lysine constituting 24 mol % and hist...

Sperm whales (Physeter macrocephalus) have followed fishing vessels off the Alaskan coast for decades, in order to remove sablefish (”depredate”) from longlines. The Southeast Alaska Sperm Whale Avoidance Project (SEASWAP) has found that whales respond to distinctive acoustic cues made by hauling fishing vessels, as well as to marker buoys on the surface. Between 15-17 August 2010 a simple two-...

The objectives were to separate canine seminal plasma proteins (with SDS-PAGE) and to determine the correlation between specific proteins and semen characteristics. Three ejaculates from 20 mixed-breed dogs, of unknown fertility, were collected by digital manipulation. Ejaculate volume and color, sperm motility, sperm vigor, percentage of morphologically normal spermatozoa, and membrane integri...

background: anti-sperm antibody (asa) can decrease sperm motility and, therefore, it is a cause of male infertility. the aim of this study was to evaluate the effects of varicocelectomy on anti-sperm antibody in patients with varicocele. methods: this observational study was conducted on 90 patients with varicocele at sina and imam khomeini hospitals during 2006 to 2009. all varicocelectomy can...

background: spinal cord injury (sci) occurs most often to young men at the peak of their reproductive health. only 10% of sci men can father children without medical assistance due to potential impairments in ejaculation and sperm quality. objective: the main objective of this experimental study was to evaluate the epididymal necrospermia- sperm death, after chronic sci in rat. materials and me...

With the recognition, afforded by recent evolutionary science, that female infidelity was a recurrent feature of modern humans’ evolutionary history has come the development of a unique area in the study of human mating: sperm competition. A form of male–male postcopulatory competition, sperm competition occurs when the sperm of two or more males concurrently occupy the reproductive tract of a ...