Observations on the Menkes' and brindled mouse phenotypes in cell hybrids

Somatic cell fusion was used to study the genetic defect in Menkes' disease and in the brindled mouse mutant. Eight hybrids derived from fusion of Menkes' fibroblasts with HeLa cells and 11 hybrids between a brindled mouse fetal cell line and a mouse A9 cell were studied. The hybrids showed copper isotope uptake intermediate between the mutant and nonmutant lines and copper isotope efflux similar to that of the nonmutant parent. These results indicate that complementation studies between the mutants should be possible.