DNA repair and the evolution of transformation in Bacillus subtilis. II. Role of inducible repair

Journal Article · Wed Mar 01 04:00:00 EST 1989 · Genetics; (United States)

OSTI ID:6068703

Wojciechowski, M F; Hoelzer, M A; Michod, R E

In Bacillus subtilis, DNA repair and recombination are intimately associated with competence, the physiological state in which the bacterium can bind, take up and recombine exogenous DNA. Previously, we have shown that the homologous DNA transformation rate (ratio of transformants to total cells) increases with increasing UV dosage if cells are transformed after exposure to UV radiation (UV-DNA), whereas the transformation rate decreases if cells are transformed before exposure to UV (DNA-UV). In this report, by using different DNA repair-deficient mutants, we show that the greater increase in transformation rate in UV-DNA experiments than in DNA-UV experiments does not depend upon excision repair or inducible SOS-like repair, although certain quantitative aspects of the response do depend upon these repair systems. We also show that there is no increase in the transformation rate in a UV-DNA experiment when repair and recombination proficient cells are transformed with nonhomologous plasmid DNA, although the results in a DNA-UV experiment are essentially unchanged by using plasmid DNA. We have used din operon fusions as a sensitive means of assaying for the expression of genes under the control of the SOS-like regulon in both competent and noncompetent cell subpopulations as a consequence of competence development and our subsequent experimental treatments. Results indicate that the SOS-like system is induced in both competent and noncompetent subpopulations in our treatments and so should not be a major factor in the differential response in transformation rate observed in UV-DNA and DNA-UV treatments. These results provide further support to the hypothesis that the evolutionary function of competence is to bring DNA into the cell for use as template in the repair of DNA damage.

• Research Organization: Univ. of Arizona, Tucson (USA)
• OSTI ID: 6068703
• Journal Information: Genetics; (United States), Journal Name: Genetics; (United States) Vol. 121:3; ISSN GENTA
• Country of Publication: United States
• Language: English

Related Subjects

560130* -- Radiation Effects on Microorganisms
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACILLUS
BACILLUS SUBTILIS
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL EVOLUTION
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
CELL TRANSFORMATIONS
DNA REPAIR
ELECTROMAGNETIC RADIATION
ENZYME INDUCTION
ENZYMES
GALACTOSIDASE
GENE OPERONS
GENE RECOMBINATION
GENE REGULATION
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
GLYCOSYL HYDROLASES
HYDROLASES
MICROORGANISMS
MUTATIONS
O-GLYCOSYL HYDROLASES
PLASMIDS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
ULTRAVIOLET RADIATION