Nid1^tm1Dong

A genomic fragment encompassing a portion of the promoter and exon 1 of the functional locus was replaced with a hygromycin selection cassette inserted by homologous recombination. Transcript was undetected by Northern blot and RT-PCR analyses of RNA obtained from homozygous mutant skeletal muscle. Western blot analysis of homozygous mutant ES cells indicated an absence of protein both in the absence and presence of retinoic acid. (J:80843)