title: Ultraviolet irradiation mutagenesis and recombination in Spiroplasma citri.
abstract: A method for obtaining and screening uv-induced mutants from Spiroplasma citri is described. Lethality response curves showed that S. citri is more sensitive to uv irradiation than are other microorganisms. The presence of a shoulder in the lethality response curve showed the existence of systems able to repair uv-induced DNA damages. Toxic-resistant mutants have been obtained. A uv fluence equal to 10 J/m2 multiplied by 2.5 X 10(3) gave the spontaneous mutation frequency. Arsenic acid- and xylitol-resistant mutants were used to investigate transfer of genetic information in S. citri. After 90 min of incubation, the recombination frequency was 5 X 10(-5).
mesh_terms: D001149:Arsenates / Q000494:pharmacology; D004269:DNA, Bacterial / Q000528:radiation effects; D004352:Drug Resistance, Microbial; D009154:Mutation / Q000528:radiation effects*; D011995:Recombination, Genetic / Q000528:radiation effects*; D013149:Spiroplasma / Q000235:genetics / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014993:Xylitol / Q000494:pharmacology
chemical_list: D001149:Arsenates; D004269:DNA, Bacterial; C025657:arsenic acid; D014993:Xylitol