The endogenous locus was disrupted by the insertion of a gene trap vector into intron 3. The vector consisted of an engrailed 2 intron, splice acceptor site, beta-geo, and polyadenylation signal. Northern blot and RT-PCR analyses of mutant mice identified truncated transcript encoding the first 47 residues. Wild-type transcript was undetected in homozygous mutant mice. (J:86562)