Cellular heredity in haploid cultures of somatic cells. Progress report, August 1978-September 1979

During the past year, studies were continued on the relation of ultraviolet mutagenesis to DNA repair in cultures of the haploid frog cell line ICR 2A. The method of irradiation of cells in suspension was improved by construction of an improved detector with major sensitivity to the 254 nm Hg resonance line, to give better estimates of actual exposure of the cells. Using this method, dose-response and dose-fractionation studies on irradiation of ouabain resistance were carried out. The uv induction of this phenotype in the ICR 2A cell line was found to be less than that necessary for adequate analysis of dose-response curves. Cell fusion experiments using frog and mouse cells revealed an enhancement of mutagenesis in the mouse parent that will be explored in further work