Reductone effect on UV-irradiated starved E. coli cells
Creators
- 1. Universidade do Estado do Rio de Janeiro (Brazil). Inst. de Biologia
Description
A starvation-induced resistence enhancement (SIRE) to UV and reductone treatments was observed in repair-profient E. coli cells. The UV-reductone positive interaction, which is possibly related to excision repair mechanisms, was not modified by prestarvation when all cells in culture had completed their round of DNA replication. In irradiated prestarved reductone-treated cells, a decrease in the DNA degradation rate was detected after the removal of reductone and the induction of a lower number of DNA single-strand breaks. The induction kinectics of DNA single-strand breaks in prestarved UV-irradiated and the repair kinetics of these lesions are slower than in non-starved cells. The resistance enhancement demonstrated under these conditions could be justified either by the generation of fewer doubles strand breaks during repair or by the possibility of repair of these lesions. (Author)
Abstract (Portuguese)
Um aumento de resistencia ao UV e a redutona foi observado em celulas de E. colli proficientes nos mecanismos de reparo, quando carenciadas. No entanto, a interacao positiva UV-redutona, que estaria relacionada ao mecanismo de reparo por excisao, nao e modificada pela carencia previa, condicao na qual se propicia o termino da replicacao residual do DNA de celulas em cultura na fase exponencial. Detectou-se uma diminuicao na taxa de degradacao do DNA de celulas previamente carenciadas quando irradiadas, tratadas ou nao com redutona, apos remocao desta substancia, como tambem a formacao de um menor numero de roturas em seu DNA; as cineticas de formacao de roturas simples em DNA de celulas carenciadas, irradiadas e/ou tratadas com redutona, bem como o reparo dessas lesoes, se mostraram mais lentas em celulas carenciadas. O aumento de resistencia verificado nestas condicoes poderia ser justificado tanto pela formacao de um menor numero de roturas duplas durante o processo de reparo como pela possibilidade de reparo dessas lesoes. (Autor)Additional details
Publishing Information
- Journal Title
- Rev. Bras. Genet.
- Journal Volume
- 5
- Journal Issue
- 1
- Series
- Rev. Bras. Genet.
- Journal Page Range
- 15-29
- ISSN
- 0100-8455
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 14723864
- Subject category
- S63: RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS;
- Descriptors DEI
- BIOLOGICAL REPAIR; ESCHERICHIA COLI; FASTING; PHOTOSENSITIVITY; SURVIVAL CURVES; TRITIUM; ULTRAVIOLET RADIATION
- Descriptors DEC
- BACTERIA; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BIOLOGICAL RECOVERY; ELECTROMAGNETIC RADIATION; HYDROGEN ISOTOPES; ISOTOPES; LIGHT NUCLEI; MICROORGANISMS; NUCLEI; ODD-EVEN NUCLEI; RADIATIONS; RADIOISOTOPES; SENSITIVITY; YEARS LIVING RADIOISOTOPES