Kcnj5^tm1Clph

A neomycin selection cassette replaced exon 1, which encodes the amino and carboxyl termini, both transmembrane domains, and the putative pore-lining sequence. Northern blot analysis of total atrial RNA showed an absence of normal transcript in homozygous mutant mice. mRNA levels of other K+ inwardly-rectifying channels, were shown to be unaffected by the targeting event by rehybridization of the Northern blot using Kcnj3-, Kcnj6- and Kcnj9-specific probes. Western blot analysis of protein extracts derived from atrial cell membranes showed that the targeted Kcnj5 protein product was absent, and levels of both glycosylated and unglycosylated forms of Kcnj3 were significantly reduced in homozygous mutant mice. (J:45533)