Genetic basis for Ly-6- defect: complementation between Ly-6- and Thy-1- mutant cell lines.

Selection of antigen loss variants from the BW5147 cell line after chemical mutagenesis, using antibodies to Thy-1.1, Ly-6.2 and H9/25 allospecificities, produced cell lines with a pleiotropic defect in cell surface antigen expression; selection against any antigen led to the loss of all three determinants. The genetic basis for the mutant phenotype has been analyzed by gene complementation by somatic cell hybridization between Ly-6- or H9/25- and Thy-1- mutants, which comprise different Thy-1 gene complementation classes. The Ly-6- and H9/25- mutants can be classified as belonging to either the A or E Thy-1- mutant class.