Centromeres exert vital cellular functions in mitosis and meiosis. A specialized histone and other chromatin-bound factors nucleate a dynamic protein assembly that is required for the proper segregation of sister chromatids. In several organisms, including the fission yeast, Schizosaccharomyces pombe, the RNAi pathway contributes to the formation of silent chromatin in pericentromeric regions. ...

background: pyridaben, a pyridazinone derivative, is a new acaricide and insecticide for control of mites and some insects such as white flies, aphids and thrips. objective: this study was designed to elucidate how pyridaben can affect the sperms' morphological parameters, its dna integrity, and to estimate the effect of various quantities of pyridaben on in vitro fertilization rate. materials ...

objective: surgery is considered the primary treatment for male infertility from clinical varicocele. one of the main events associated with varicocele is excessive production of reactive oxygen species (ros). n-acetyl-l-cysteine (nac), an antioxidant that scavenges free radicals, is considered a supplement to alleviate glutathione (gsh) depletion during oxidative stress. despite beneficial eff...

The integrity of DNA molecules is constantly challenged. All organisms have developed mechanisms to detect and repair multiple types of DNA lesions. The basic principles of DNA damage repair (DDR) in prokaryotes and unicellular and multicellular eukaryotes are similar, but the association of DNA with nucleosomes in eukaryotic chromatin requires mechanisms that allow access of repair enzymes to ...

In eukaryotes, each of the more than 100 copies of ribosomal RNA (rRNA) genes exists in either an RNA polymerase I transcribed open chromatin state or a nucleosomal, closed chromatin state. Open rRNA genes guarantee the cell's supply with structural components of the ribosome, whereas closed rRNA genes ensure genomic integrity. We report that the observed balance between open and closed rRNA ge...

R loops are transcription byproducts that constitute a threat to genome integrity. Here we show that R loops are tightly linked to histone H3 S10 phosphorylation (H3S10P), a mark of chromatin condensation. Chromatin immunoprecipitation (ChIP)-on-chip (ChIP-chip) analyses reveal H3S10P accumulation at centromeres, pericentromeric chromatin, and a large number of active open reading frames (ORFs)...

The integrity of DNA molecules is constantly challenged. All organisms have developed mechanisms to detect and repair multiple types of DNA lesions. The basic principles of DNA damage repair (DDR) in prokaryotes and unicellular and multicellular eukaryotes are similar, but the association of DNA with nucleosomes in eukaryotic chromatin requires mechanisms that allow access of repair enzymes to ...

Abnormalities in the male genome are a clear potential reason for post fertilization failure. Male infertility may arise due to high levels of loosely packaged chromatin and damaged DNA. The achievement of a correct chromatin packaging level is essential for successful fertilization. The chromatin contained in the nuclei of mammalian spermatozoa is an extremely compact and stable structure. The...