Gene transfer of a putative mammalian K+ channel gene from genomic and cosmid DNA

We have successfully transfected mouse genomic DNA containing a mutant putative K+ channel gene into murine LMTK- cells. Incorporation of the mutant gene allowed primary transformants to express the mutant cell phenotype of growth at a subthreshold K+ concentration and, furthermore, caused these primary transformants to display the same characteristics of growth and unidirectional K+ flux as the mutant cell line, LTK-1, from which the genomic DNA was derived. A cosmid genomic library was formed from LTK-1 mutant DNA and shown by transfection experiments to contain at least one unique cosmid clone containing a functional copy of the mutant putative K+ channel gene.