Sunlight mutagenesis: changes in mutational specificity during the irradiation of phage M13mp2.
Mutat Res
; 438(1): 53-62, 1999 Jan 02.
Article
em En
| MEDLINE
| ID: mdl-9858683
ABSTRACT
We reported previously that the mutations in phage M13mp2, a single-stranded DNA phage, induced by sunlight exposure are predominated by G-to-C transversions. We have now made an unexpected observation that an exposure to sunlight for a short period of time results in induction mainly of C-to-T transitions while a longer exposure results in the induction of G-to-C transversions. This peculiar phenomenon suggests that DNA damage formed by initial sunlight exposure can be transformed during an elongated exposure. 7, 8-Dihydro-8-oxoguanine (8-oxoG) in DNA might be involved in the shift of the mutational specificity, as 8-oxoG was formed in the phage DNA upon the sunlight exposure. We also compared the mutagenic activity of UVB irradiation with that of sunlight exposure. The results demonstrate that the genotoxic properties of sunlight and UVB in phage M13mp2 mutagenesis are different. The shift in the mutational specificity associated with the dose of the sunlight may call for general cautions in the studies of agent-induced mutagenesis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Luz Solar
/
Raios Ultravioleta
/
Bacteriófago M13
/
Escherichia coli
Idioma:
En
Revista:
Mutat Res
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Japão