Single strand and double strand DNA damage-induced recombination were compared in the yeast Saccharomyces cerevisiae. The non-replicating plasmid pUC18-HIS3 was damaged in vitro and introduced into yeast cells; plasmid-chromosome recombinants were selected as stable His+ transformants. Single strand damage was produced by UV irradiation at 254 nm or by psoralen photoreaction at 390 nm. Double strand damage was produced by psoralen photoreaction at 350 nm or by restriction endonuclease digestion. Recombinants were classified as resulting from gene conversion without crossing over, single plasmid integration, or multiple plasmid integration. Single and double strand DNA damage produced different patterns of recombination. In repair proficient cells double strand damage induced primarily multiple plasmid integrations, while single strand damage induced higher proportions of gene conversions and single integrations. Reciprocal recombination depended on the RAD1 gene, which is involved in both excision repair and recombination; plasmid integration induced by all forms of damage was decreased in a rad1 disruption strain. Mutation of the RAD3 excision repair gene decreased plasmid integration induced by far UV irradiation and psoralen crosslinks, but not by double strand breaks, which are not substrates of nucleotide excision repair. Double strand break-induced plasmid integration was also decreased by disruption of RAD10, which forms a complex with RAD1; disruption of RAD4 had no effect. Thus, while nucleotide excision repair genes are involved in the processing of damaged DNA to generate recombination intermediates, RAD1 and RAD10 are additionally involved in reciprocal exchange.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.