Background: H2AX is a histone variant that is systematically found and ubiquitously distributed throughout the genome. DNA double-strand breaks (DSBs) induce phosphorylation of H2AX at serine 139 (γH2AX), an immunocytochemical assay with antibodies recognizing γH2AX has become the gold standard for the detection of DSBs. The importance of this assay to investigate different individu...

Sample preparation procedures for the pulsed-field gel electrophoresis (PFGE) assay usually involve a lysis step at temperatures as high as 50 degrees C. During this warm-lysis procedure, multiply damaged sites containing heat-labile sites (HLS) can be converted into double-strand breaks (DSB). Once formed, these DSB cannot be distinguished from the DSB formed directly by ionizing radiation. Th...

Meiotic recombination, an essential aspect of sexual reproduction, is initiated by programmed DNA double-strand breaks (DSBs). DSBs are catalyzed by the widely-conserved Spo11 enzyme; however, the activity of Spo11 is regulated by additional factors that are poorly conserved through evolution. To expand our understanding of meiotic regulation, we have characterized a novel gene, dsb-1, that is ...

For most organisms, chromosome segregation during meiosis relies on deliberate induction of DNA double-strand breaks (DSBs) and repair of a subset of these DSBs as inter-homolog crossovers (COs). However, timing and levels of DSB formation must be tightly controlled to avoid jeopardizing genome integrity. Here we identify the DSB-2 protein, which is required for efficient DSB formation during C...

The purpose of this study was to determine whether there are any consistent spirometric or Dsb findings in patients with LV dysfunction characterized by a clinical diagnosis of CHF and an EF less than 40 percent. We performed spirometry and Dsb in 34 patients, and found that EF correlated only with Dsb. When we separated the patients into those with rales and those without, Dsb correlated stron...

Emerging evidence indicate that the mammalian checkpoint kinase ATM induces transcriptional silencing in cis to DNA double-strand breaks (DSBs) through a poorly understood mechanism. Here we show that in Saccharomyces cerevisiae a single DSB causes transcriptional inhibition of proximal genes independently of Tel1/ATM and Mec1/ATR. Since the DSB ends undergo nucleolytic degradation (resection) ...

Homologous recombination plays a key role in the repair of double-strand breaks (DSBs), and thereby significantly contributes to cellular tolerance to radiotherapy and some chemotherapy. DSB repair by homologous recombination is initiated by 5' to 3' strand resection (DSB resection), with nucleases generating the 3' single-strand DNA (3'ssDNA) at DSB sites. Genetic studies of Saccharomyces cere...

Homologous recombination (HR) initiates double-strand break (DSB) repair by digesting 5'-termini at DSBs, the biochemical reaction called DSB resection, during which DSBs are processed by nucleases to generate 3' single-strand DNA. Rad51 recombinase polymerizes along resected DNA, and the resulting Rad51-DNA complex undergoes homology search. Although DSB resection by the Mre11 nuclease plays a...

To expand the known spectrum of genes that maintain genome stability, we screened a recently released collection of temperature sensitive (Ts) yeast mutants for a chromosome instability (CIN) phenotype. Proteasome subunit genes represented a major functional group, and subsequent analysis demonstrated an evolutionarily conserved role in CIN. Analysis of individual proteasome core and lid subuni...