Background: Although the pathophysiology of the testicular damage associated with varicocele remains unclear, but varicocelectomy is considered a suitable technique for the treatment of individuals with clinical varicocele. The current study was designed to assessed semen parameters, chromatin packaging, and pregnancy outcome before and after varicocelectomy. Materials and Methods: Semen sample...

Dinoflagellates are unique among eukaryotes in their unusual 'dinokaryons' - nuclei that lack bulk histones. A new study finds that acquisition of a novel dinoflagellate chromatin protein was an early step in the transition to a nucleus lacking detectable nucleosomes.

The quality of sperm ejaculated by bonnet monkeys and normal, healthy proven fertile volunteer men, both actively immunized with ovine follicle-stimulating hormone (oFSH), was examined at different times of study for chromatin packaging and acrosomal glycoprotein concentration by flow cytometry. Susceptibility of sperm nuclear DNA to dithiothreitol (DTT)-induced decondensation, as measured by e...

Sperm nuclear morphometry quantifies properties of the nucleus and allows comparison between semen samples. Chromatin packaging is one of the properties reflected by nuclear measures, and has been related to fertility as correct packaging is essential for not only fertilization but also successful early embryonic development. One such morphometric measure is texture. Nuclear texture is thought ...

In order to efficiently edit eukaryotic genomes, it is critical to test the impact of chromatin dynamics on CRISPR/Cas9 function and develop strategies to adapt the system to eukaryotic contexts. So far, research has extensively characterized the relationship between the CRISPR endonuclease Cas9 and the composition of the RNA-DNA duplex that mediates the system's precision. Evidence suggests th...

The alignment, folding and packaging of cricket chromatin was examined during late spermiogenesis by an electron-microscope study of nuclei dispersed by air--liquid surface tension forces after detergent treatment. Late developing spermatid genomes arrange themselves in multiple packaging units in a stepwise process which includes: (1) a loss of the beaded repeating structure of chromatin as nu...

Packaging of eukaryotic genomes into chromatin affects every process that occurs on DNA. The positioning of nucleosomes on underlying DNA plays a key role in the regulation of these processes, as the nucleosome occludes underlying DNA sequences. Here, we review the literature on mapping nucleosome positions in various organisms, and discuss how nucleosome positions are established, what effect ...

Eukaryotic genomic DNA is combined with histones, nonhistone proteins, and RNA to form chromatin, which is extensively packaged hierarchically to fit inside a cell's nucleus. The nucleosome-comprising a histone octamer with 147 base pairs of DNA wrapped around it-is the initial level and the repeating unit of chromatin packaging, which electron microscopy first made visible to the human eye as ...

When a eukaryotic cell divides, tension builds at centromeres as spindle forces pull chromosomes toward opposite poles during metaphase. New data show that centromeric chromatin stretches in response to these forces, revealing a mechanical role for chromatin packaging in mitosis.