Background: Intra-cytoplasmic sperm insemination, the ICSI, is considered as the one most routine treatment of male infertility. Although the genetic inheritance of an individual is based on the genetic contribution from both the oocyte and sperm, considering the fact that ICSI by passes all the barriers to natural fertilization much emphasis was given to oocyte quality to improve the ICSI outc...

DNA damage signaling and repair machineries operate in a nuclear environment where DNA is wrapped around histone proteins and packaged into chromatin. Understanding how chromatin structure is restored together with the DNA sequence during DNA damage repair has been a topic of intense research. Indeed, chromatin integrity is central to cell functions and identity. However, chromatin shows remark...

Current methods of analyzing sperm chromatin competency overlook the inner sperm compartment which is inaccessible to probes and reagents. By breaking the molecular protamine disulfide bridges, the DNA toroids are exposed to integrity analysis. The aim was to develop a simple nuclear toroid test and determine its association with fertilization, pregnancy, and miscarriage. The approach involved ...

BACKGROUND The influence of ejaculatory abstinence (EA) on semen parameters and subsequent reproductive outcome is still debatable; hence understanding the impact of EA on sperm structural and functional integrity may provide a valuable information on predicting successful clinical outcome. OBJECTIVE To understand the influence of EA on sperm chromatin maturity, integrity, longevity and globa...

We recently reported that reducing the levels of BRG1, the catalytic subunit of mammalian SWI/SNF chromatin remodeling enzymes, induces alterations in nuclear shape in a breast epithelial cell line. Immunostaining the BRG1 knockdown cells with nuclear lamina antibodies revealed a significantly increased frequency of grooves, or invaginations, in the nuclei. Disruption of each of the major cytop...

DNA double-strand breaks (DSBs) not only interrupt the genetic information, but also disrupt the chromatin structure, and both impairments require repair mechanisms to ensure genome integrity. We showed previously that RNF8-mediated chromatin ubiquitylation protects genome integrity by promoting the accumulation of repair factors at DSBs. Here, we provide evidence that, while RNF8 is necessary ...

Genomic DNA is organized three-dimensionally in the nucleus, and is thought to form compact chromatin domains. Although chromatin compaction is known to be essential for mitosis, whether it confers other advantages, particularly in interphase cells, remains unknown. Here, we report that chromatin compaction protects genomic DNA from radiation damage. Using a newly developed solid-phase system, ...

To maintain genome integrity, eukaryotic cells initiate DNA replication once per cell cycle after assembling prereplicative complexes (preRCs) on chromatin at the end of mitosis and during G1. In S phase, preRCs are disassembled, precluding initiation of another round of replication. Cdt1 is a key member of the preRC and its correct regulation via proteolysis and by its inhibitor Geminin is ess...

During cell division, genome integrity is maintained by faithful DNA replication during S phase, followed by accurate segregation in mitosis. Many DNA metabolic events linked with DNA replication are also regulated throughout the cell cycle. In eukaryotes, the DNA sliding clamp, proliferating cell nuclear antigen (PCNA), acts on chromatin as a processivity factor for DNA polymerases. Since its ...

Nucleosomes are the core units of cellular chromatin and are comprised of 147 base pairs (bp) of DNA wrapped around an octamer of histone proteins. Proteins such as chromatin remodelers, transcription factors, and DNA repair proteins interact dynamically with chromatin to regulate access to DNA, control gene transcription, and maintain genome integrity. The extent of association with chromatin ...