Background During mammalian spermatogenesis unique and dynamic epigenetic events occur leading to chromatin condensation. Through these events, histone demethylases such as JMJD1A play important roles in compaction of sperm chromatin, due to regulation of histone methylation dynamics and alteration of chromatin structure. As �histone methylation� is one of the best-characterized modifications i...

The mammalian spermatozoon has a unique chromatin structure where the majority of DNA is packaged by protamines, while a small fraction (∼8%) remains associated with nucleosomes. However, the chromatin affinity and repertoire of the additional proteins constituting the different sperm chromatin fractions have not yet been explored. To address this we have carried out a genomic and proteomic cha...

Background: Cytoplasm and mitochondria are considered as the major origins of sperm ROS production. Sperm is prone to DNA damage by exposure to ROS or due impaired chromatin remodeling or low DNA protamination. Therefore, the aim of this study was to see if there is any association between impaired chromatin packaging and origin of ROS production. Materials and Methods: Cytosolic ROS, mitochond...

BACKGROUND Methamphetamine (MA) was shown to have harmful effects on male reproductive system. OBJECTIVE To investigate probable effects of daily administration of MA on sperm parameters and chromatin/DNA integrity in mouse. MATERIAL AND METHODS Thirty-five NMRI male mice were divided into five groups including low, medium, and high dosage groups which were injected intraperitoneally with 4...

Sperm chromatin/DNA damage can be measured by a variety of assays. However, it has been reported that these tests may lose prognostic value in Assisted Reproductive Technology (ART) cycles when assessed in post-prepared samples, possibly due to the normalizing effect promoted by sperm preparation procedures. We have recently implemented a modified version of the Diff-Quik staining assay that al...

Sperm chromatin integrity has been being recognized as an important factor in male fertility. During normal fertilization, high quality sperm with intact chromatin are selected through natural selection in journey from vagina to fallopian tube. However, using Assisted Reproductive Techniques, particularly ICSI, the natural selection is bypassed. Therefore sperm with DNA breakage have the opport...

background: it is estimated that about 50% of causes of recurrent pregnancy loss (rpl) cases remain unknown. sperm factors are suggested to have probable role in cases with rpl. objective: the goal was to determine the possible relationship between semen bacterial contaminations with unexplained rpl. also, the correlation between number of bacterial colony and sperm chromatin condensation was e...

This study was conducted to determine chromatin integrity and DNA damage by DNA electrophoresis and comet assays of buffalo fresh and frozen semen. Semen samples were collected from four buffalo bulls and evaluated after freezing for semen motility, viability, sperm abnormalities, chromatin integrity and DNA damage. A significant variation was found in semen parameters after thawing. Highly sig...

Zona-free oocytes of the mouse were inseminated at prometaphase I or metaphase I of meiotic maturation in vitro, and the behavior of the sperm nuclei within the oocyte cytoplasm was examined. If the oocytes were penetrated by up to three sperm, maturation continued during subsequent incubation and became arrested at metaphase II. Meanwhile, each sperm nucleus underwent the following changes. Fi...

background: exposures to lead above the threshold value of 50–60 μg/dl have been linked to diminished semen quality parameters. worldwide, the lead exposure has been diminished during the last years. therefore, it has become of a great concern to examine the effects of lead exposures on semen quality at low levels of exposure. objective: to evaluate the effect of low level (<20 μg/dl) blood lea...