Correlation between glucocorticoid receptor and cytolytic response of murine lymphoid cell lines

By fusion between murine thymoma lines which are either homozygous (r+/r+ or r-/r-) or hemizygous (r+/r-) for the glucocorticoid receptor structural gene r, hybrid clones have been obtained which carry one, two three, or four copies of the r+ allele. These hybrids contain different amounts of normal glucocorticoid receptor as the result of a r+ gene dosage effect. Measurements of the cytolytic response of these hybrids to dexamethasone indicate a tight correlation between receptor content and sensitivity.