Replication forks stall at different DNA obstacles such as those originated by transcription. Fork stalling can lead to DNA double-strand breaks (DSBs) that will be preferentially repaired by homologous recombination when the sister chromatid is available. The Rrm3 helicase is a replisome component that promotes replication upon fork stalling, accumulates at highly transcribed regions and preve...

DNA sequences capable of adopting non-canonical secondary structures have been associated with gross-chromosomal rearrangements in humans and model organisms. Previously, we have shown that long inverted repeats that form hairpin and cruciform structures and triplex-forming GAA/TTC repeats induce the formation of double-strand breaks which trigger genome instability in yeast. In this study, we ...

Cigarette smoking is considered to be the single most important acquired cause of cancer mortality. Studies of chromosome aberrations, sister chromatid exchanges, and fragile sites in peripheral blood or bone marrow are useful methods to detect the effects of the environmental mutagens or carcinogens found in cigarette smoke. The effects of smoking on the immature cells in the bone marrow have ...

Lymphocytes from 15 untreated patients with non-Hodgkin lymphoma (NHL) and 15 controls were exposed to 0.08 micrograms/ml mitomycin C, and the frequency and distribution of structural chromosome aberrations (chromatid and chromosome gaps, breaks, and exchanges) were analyzed in 100 mitoses per subject. The mean frequencies of aberrant cells, and gap, break, and gap + break events were 8.7, 0.9,...

The rate of chromatid breaks was studied in cows with a history of sub-fertility by means of a test based on measurement of the average of breaks induced in lymphocytes of peripheral blood cultures. Fourteen female specimens were divided into two groups: fertile and sub-fertile. Peripheral blood lymphocytes were cultured and prepared for cytogenetic analysis. Two types of culture were establish...

In budding yeast, the mitotic spindle is comprised of 32 kinetochore microtubules (kMTs) and approximately 8 interpolar MTs (ipMTs). Upon anaphase onset, kMTs shorten to the pole, whereas ipMTs increase in length. Overlapping MTs are responsible for the maintenance of spindle integrity during anaphase. To dissect the requirements for anaphase spindle stability, we introduced a conditionally fun...

DNA damage (alkaline filter elution) and sister chromatid exchange (SCE) frequencies were measured in lymphocytes of 39 welders and 39 controls. The welders showed a significantly higher rate of DNA single-strand breakages and significantly elevated SCE values. These results are not in accordance with those of a former study in which only DNA-protein cross-links were measured. The different res...

Spontaneous and clastogen-induced chromosomal instability in a high-risk group (i.e, 33 patients with rectal carcinomas) was investigated using peripheral blood lymphocytes as target cells. In addition to the analysis of spontaneous and clastogen-induced chromosome aberrations, this study also included classical karyotype analysis and scoring of sister chromatid exchanges (SCE) in some of the p...

BACKGROUND Chromosome instability is the most common form of genomic instability. Genomic instability can lead to tumorogenesis. High level of chromosomal aberrations in peripheral blood lymphocytes can be used as a biomarker for cancer. Air pollution is one of the most important factors that cause chromosomal instability (CIN). In this comparative study we used classic Cytogenetic technique to...