The increased sensitivity of ataxia telangiectasia cells towards ionizing radiation may be related to their inability to incise DNA near sites of radiation-induced base damages. When compared to 3 unaffected controls, crude extracts from 5 lines of fibroblast cells derived from ataxia telangiectasia patients were capable of incising γ-irradiated DNA to the same extent as normal cells as determined in a nicking assay, using the circular replicative form of φX174. However, the types of alterations introduced into DNA by γ-irradiation could be distinguished from sites of base loss due to depurination or depyrimidination and from sites of base modification by OsO4. The specific endonuclease involved was demonstrated to be distinct from the apurinic endonuclease by its rate of temperature inactivation.
|Original language||English (US)|
|Number of pages||6|
|Journal||Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis|
|State||Published - Dec 1979|
ASJC Scopus subject areas
- Molecular Biology
- Health, Toxicology and Mutagenesis