Open AccessUV Stimulation of Chromosomal Marker Exchange in Sulfolobus acidocaldarius: Implications for DNA Repair, Conjugation and Homologous Recombination at Extremely High Temperatures
Author(s) -
Katherine Schmidt,
Kristen E. Beck,
Dennis W. Grogan
Publication year - 1999
Publication title -
genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.792
H-Index - 246
eISSN - 1943-2631
pISSN - 0016-6731
DOI - 10.1093/genetics/152.4.1407
Subject(s) - sulfolobus acidocaldarius , homologous recombination , biology , dna , recombination , dna repair , stimulation , chromosome , homologous chromosome , genetics , biophysics , microbiology and biotechnology , archaea , bacteria , gene , neuroscience
The hyperthermophilic archaeon Sulfolobus acidocaldarius exchanges and recombines chromosomal markers by a conjugational mechanism, and the overall yield of recombinants is greatly increased by previous exposure to UV light. This stimulation was studied in an effort to clarify its mechanism and that of marker exchange itself. A variety of experiments failed to identify a significant effect of UV irradiation on the frequency of cell pairing, indicating that subsequent steps are primarily affected, i.e., transfer of DNA between cells or homologous recombination. The UV-induced stimulation decayed rather quickly in parental cells during preincubation at 75 degrees, and the rate of decay depended on the incubation temperature. Preincubation at 75 degrees decreased the yield of recombinants neither from unirradiated parental cells nor from parental suspensions subsequently irradiated. We interpret these results as evidence that marker exchange is stimulated by recombinogenic DNA lesions formed as intermediates in the process of repairing UV photoproducts in the S. acidocaldarius chromosome.