The first 2 exons and half of exon 3 were replaced by cDNA encoding lacZ and a pGK neo cassette, bringing the beta-galactosidase cDNA under the control of the endogenous promoter while ablating the endogenous gene. Northern and Western blot analysis on skeletal muscle confirmed absence of Ankrd2 RNA and protein, respectively. (J:125819, J:214867)