Transcription and double-strand breaks induce similar mitotic recombination events in Saccharomyces cerevisiae.
We have made a comparative analysis of double-strand-break (DSB)-induced recombination and spontaneous recombination under low- and high-transcription conditions in yeast. We constructed two different recombination substrates, one for the analysis of intermolecular gene conversions and the other for intramolecular gene conversions and inversions. Such substrates were based on the same leu2-HOr allele fused to the tet promoter and containing a 21-bp HO site. Gene conversions and inversions were differently affected by rad1, rad51, rad52, and rad59 single and double mutations, consistent with the actual view that such events occur by different recombination mechanisms. However, the effect of each mutation on each type of recombination event was the same, whether associated with transcription or induced by the HO-mediated DSB. Both the highly transcribed DNA and the HO-cut sequence acted as recipients of the gene conversion events. These results are consistent with the hypothesis that transcription promotes initiation of recombination along the DNA sequence being transcribed. The similarity between transcription-associated and DSB-induced recombination suggests that transcription promotes DNA breaks.
González-Barrera
Sergio
S
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Spain.
García-Rubio
María
M
Aguilera
Andrés
A
D007446:Chromosome Inversion; D004249:DNA Damage; D045643:DNA Repair Enzymes; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004720:Endonucleases / Q000235:genetics / Q000378:metabolism; D005785:Gene Conversion / Q000502:physiology; D051135:Rad51 Recombinase; D051721:Rad52 DNA Repair and Recombination Protein; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; C497197:RAD52 protein, S cerevisiae; C400213:RAD59 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; C495151:RAD51 protein, S cerevisiae; D051135:Rad51 Recombinase; D004720:Endonucleases; C069266:RAD1 protein, S cerevisiae; D045643:DNA Repair Enzymes