engleski

Influence of homology size and polymorphysm on plasmid integration in the yeast CYC1 DNA region

We studied the influence of homology size and polymorphism on integration of circular plasmids into the yeast CYC1 region. The plasmids used also contained the URA3 gene and the proportion of Ura+ transformants resulting from plasmid integration into the CYC1 region was determined by Southern blot analysis. A size-dependent decrease in integration into the CYC1 region was observed from 858 bps to 363 bps of homology. However, with homology size of 321, 259 or 107 bps, about 2% of transformants still contained plasmid molecule integrated in the CYC1 region. A single point mutation in the 858 bp fragment decreased the proportion of integrations to the CYC1 gene but the presence of additional mutations did not have a cumulative effect. For plasmids isolated in single-stranded (ss) form, the presence of two or six point mutations did not influence integration. These results were compared with those obtained in other assays designed to study substrate requirements for homologous recombination

DNA homology; recombination; Integrative plasmids; yeast

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