Excision of gamma-ray induced thymine lesions by preparations from ataxia telangiectasia fibroblasts.

The capacity of whole cell sonicates of skin fibroblasts of normal individuals and patients with the autosomal recessive disease Ataxia telangiectasia (AT) to remove aerobic gamma-ray products of the 5,6-dihydroxydihydrothymine type (tgamma02) from exogenous DNA substrates was investigated. All four AT strains (AT CRL 1312, AT CRL 1343, AT GM 367, AT 4BI) possessed normal capabilities to excise tgamma02 from irradiated bacteriophage DNA and irradiated chromatin isolated from normal and AT-skin fibroblasts.