The DNA of most vertebrate sperm cells is packaged by protamines. The primary structure of mammalian protamine I can be divided into three domains, a central DNA binding domain that is arginine-rich and amino- and carboxyl-terminal domains that are rich in cysteine residues. In native bull sperm chromatin, intramolecular disulfide bonds hold the terminal domains of bull protamine folded back on...

Contrary to public opinion on the causes of infertility, male factor accounts for over 50% of infertility during reproductive age of couples and even there are several reports on its increase during the recent years. Semen analysis as one of the main laboratory tests provides valuable information about male fertility status. In spite of huge development in diagnostic tests and laboratory innova...

Understanding how DNA is packaged in the mammalian sperm cell has important implications for human infertility as well as for the cell biology. Recent advances in the study of mammalian sperm chromatin structure and function have altered our perception of this highly condensed, inert chromatin. Sperm DNA is packaged very tightly to protect the DNA during the transit that occurs before fertiliza...

The integrity of the paternal genome is essential as the spermatozoon can bring genetic damage into the oocyte at fertilization and contribute to the development of abnormal pregnancy outcome. During the past two decades, many assays have been developed to measure sperm DNA strand breaks, chromatin structure and compaction and assess the proteins associated with the DNA, as well as epigenetic m...

Background: Acrylamid (AA) is found in carbohydraterich foods that are prepared at high temperatures, such as French fries and potato chips. The toxic effects of AA in male animals include degeneration of epithelial cells of seminiferous tubules, decreased number of sperm and elevation in abnormal spermatozoa. The aim of this study was to evaluate the detrimental effects of AA on sperm paramete...

Sperm competition, a prevalent evolutionary process in which the spermatozoa of two or more males compete for the fertilization of the same ovum, leads to morphological and physiological adaptations, including increases in energetic metabolism that may serve to propel sperm faster but that may have negative effects on DNA integrity. Sperm DNA damage is associated with reduced rates of fertiliza...

gibberellic acid (ga3) is a group of plant hormones identified in various plants. the aim of this study was to determine the effects of ga3 on sperm parameters and in vitro fertilization (ivf). fifty six adult male rats were divided into seven groups as, control, treatment and sham. following 15, 30 and 45 days of ga3 and methanol alcohol (ma) administration, rats were euthanized and epididymis...

background: it has been claimed that by using different washing methods, the sperms can be separated according to size, motility, density, chromosomal content and surface markings and charge. these methods also reduce sperm chromatin deficiencies and screen the sperms before applying in assisted reproduction techniques. objective: this study compared simple density gradient methods and a combin...

Background The aim of present study is to evaluate the effect of PolyVinyl Pyrrolidone (PVP) routinly used during ICSI procedure on sperm membrane integrity, and sperm chromatin status. MaterialsAndMethods This study was carried out on 21 semen samples from the infertile men referring to Isfahan Fertility and Infertility Center. The processed semen samples were divided into two portions. One po...

Background: Vitamin E is believed to be the primary component of the antioxidant system in spermatozoa. There is a relationship between activity of these antioxidant and function of sperm. Vitamins E and C which are belong to non-enzymatic antioxidant are used as a supplemented drug to improve sperm quality and male fertility. The present study was carried out to investigate the positive effect...