Abstract
Oxidative DNA damages are mainly generated by reactive oxygen species produced during cellular metabolism as well as exposure to radiation. The spectrum of DNA damage includes a wide variety of modifications of purine and pyrimidine bases. Among these modified bases, 7,8-dihydro-8-oxoguanine is an important mutagenic lesion. The mutgenic base is removed from oxidatively damaged DNA by base excision repair. Genes coding for DNA repair enzymes that recognize 8-oxoguanine have been reported in bacteria and yeast. Until now there is no study with Ciona intestinalis . In this study, we identified and characterized Ciona intestinalis cDNAs encoding the 8-oxoguanine DNA glycosylase genes. The reasons why we choose Ciona intestinails are that firstly, it's genome is the smallest of any experimentally manipulable chordate. Secondly, Ciona intestinails has a short life cycle only 6~8 weeks. Thirdly, this configuration is the most simplified and primitive chordate body plan. We found that the cDNA library from Ciona intestinails contains homologs of the human Ogg1 gene. [J Radiat Res 44:408 (2003)]
