Round spermatids contain high levels of extremely varied mRNAs that are synthesized either throughout early spermatogenesis or during spermiogenesis from the haploid genome. Concomitantly, with major changes in the chromatin organization, arrest of transcription occurs at midspermiogenesis. However, previous investigations using RT-PCR have revealed the persistence of numerous and different tra...

The purpose of this study was to investigate the efficiency of the water test to evaluate the functional membrane integrity of ejaculated canine sperm after collecting, cooling, and freezing-thawing. Twenty-five ejaculates were obtained from 12 stud dogs by digital manipulation. Sperm-rich fractions were evaluated, diluted, cooled at 5oC and frozen-thawed. A conventional hypo-osmotic swelling t...

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 ...

Sperm competition theory predicts that males should increase their expenditure on the ejaculate with increasing risk of sperm competition, but decrease their expenditure with increasing intensity. There is accumulating evidence for sperm competition theory, based on examinations of testes size and/or the numbers of sperm ejaculated. However, recent studies suggest that ejaculate quality can als...

During their epididymal maturation, stabilizing factors such as cholesterol sulfate are associated with the sperm plasma membrane. Cholesterol is sulfated in epididymal spermatozoa by the enzyme estrogen sulfotransferase. Because of its role in the efflux of sulfate conjugates formed intracellularly by sulfotransferases, the ATP-binding cassette membrane transporter G2 (ABCG2) might have a role...

The dimensions of spermatozoa from different levels of the reproductive tract were measured in 6 buffalo-bulls castrated under local anesthesia ; the same measurements were taken in the semen of 6 breeding buffalo-bulls. During transit from caput to cauda epididymis the sperm showed a significant increase in the length of head and main piece. However, a significant decrease was observed in midd...

Sections of ejaculated spermatozoa from rabbits with known fertility were observed by transmission electron microscopy. Acrosome defects, odd head shapes, the presence of spermatids and the decondensation of sperm nuclei were recorded. The fertility negatively correlated with the number of acrosomal defects, while litter size was negatively related to nuclear decompaction. Sperm nuclear deconde...

The aim of this study is to underline the role of transmission and scanning electron microscopy analysis in the diagnosis of human sperm pathologies. Among the possible causes of male infertility, defects of sperm morphology represent an important factor that may explain decreased fertilizing potential of sperm. Electron microscopy allowed us to identify systematic sperm defects that affect the...

AIM To study the influence of enterococci on human sperm membrane in vitro. METHODS Ejaculated human sperm were artificially infected with beta-hemolytic or non-beta-hemolytic enterococci at the bacteria: sperm ratio of 50:1 at 37 degrees . Sperm membrane integrity was examined after incubation for 1, 3 and 5 h by hypoosmotic swelling (HOS) test and electron microscopy. RESULTS Sperm infect...