| pubmed-article:2909865 | pubmed:abstractText | The effect of UV irradiation on viability and mutant colony frequency in the Mollicute Spiroplasma citri was investigated at 3 phases of growth. The first UV-induced mutants obtained in Mollicutes were selected: xylitol-resistant (XylR) and arsenic acid-resistant mutants (ArsR). Lethal and mutation frequency responses of S. citri cells increase with the age of the cell cultures. In all UV-irradiated populations, light exposure slightly increases the number of survivors and decreases the induced mutation frequency; liquid holding conditions increase the number of both survivors and mutant colonies. This suggests that, in UV-irradiated S. citri cells maintained under liquid holding conditions, there is no dark reactivation but induction of an error-prone repair system of the SOS type. In S. citri, the error-free light and dark repair systems are inefficient. Results allow the development of a method to select UV-induced mutations usable as markers in genetic studies of Spiroplasma cells. | lld:pubmed |
