Homologous recombinational repair (HRR) restores chromatid breaks arising during DNA replication and prevents chromosomal rearrangements that can occur from the misrepair of such breaks. In vertebrates, five Rad51 paralogs are identified that contribute in a nonessential but critical manner to HRR proficiency. We constructed and characterized a knockout of the paralog Rad51D in widely studied C...

During meiosis, homologues become juxtaposed and synapsed along their entire length. Mutations in the cohesin complex disrupt not only sister chromatid cohesion but also homologue pairing and synaptonemal complex formation. In this study, we report that Pds5, a cohesin-associated protein known to regulate sister chromatid cohesion, is required for homologue pairing and synapsis in budding yeast...

OBJECTIVE To present the initial results of first three years of implementation of a genetic evaluation test for bone marrow-derived mesenchymal stem cells in a Cell Technology Center. METHODS A retrospective study was carried out of 21 candidates for cell therapy. After the isolation of bone marrow mononuclear cells by density gradient, mesenchymal stem cells were cultivated and expanded at ...

Aberrant DNA replication is a major source of the mutations and chromosomal rearrangements associated with pathological disorders. In bacteria, several different DNA lesions are repaired by homologous recombination, a process that involves sister chromatid pairing. Previous work in Escherichia coli has demonstrated that sister chromatid interactions (SCIs) mediated by topological links termed p...

Amplification of the copy number of oncogenes is frequently associated with tumor progression. Often, the amplified DNA consists of large (tens to hundreds of kilobases) 'head-to-head' inverted repeat palindromes (amplicons). Several mechanisms have been proposed to explain palindrome formation but their relative contributions in nature have been difficult to assess without precise knowledge of...

The observation was made previously that the reduction in radiosensitivity in Vicia faba (as measured by postirradiation root growth) by prolonging the exposure time from about 10 minutes to 24 hours is much less marked at 3 degrees C. than at 19 degrees C. If chromosome damage is mainly responsible for the reduced root growth, this observation might be explained by a smaller drop in the "two-h...

In thymidylate synthase-negative mutants of mouse FM3A cells, thymidine starvation rapidly decreased mitotic activity and resulted in cell death (thymineless death). When the thymidine starvation was reversed by an addition of thymidine, mitotic activity was recovered, but the majority of mitotic cells exhibited extensive chromosome aberrations, including chromatid breaks, chromatid exchanges, ...

The combined treatment of cultures of human embryonic lung cells with herpes simplex virus type 2 and cytosine arabinoside produced a significantly increased number of cells containing multiple chromatid and chromosome breaks. The incidence of such cells was found to be approximately two and one half times greater than the additive effects of virus and cytosine arabinoside induced separately an...

The Saccharomyces cerevisae RAD3 gene is the homolog of human XPD, an essential gene encoding a DNA helicase of the TFIIH complex involved in both nucleotide excision repair (NER) and transcription. Some mutant alleles of RAD3 (rad3-101 and rad3-102) have partial defects in DNA repair and a strong hyper-recombination (hyper-Rec) phenotype. Previous studies showed that the hyper-Rec phenotype as...