Frk^tm1Liu

Exons 1a and 1b were replaced with a neomycin selection cassette. The deleted region contained the 5' untranslated region, the start codon, and sequence encoding the amino terminal residues and the SH2 and SH3 domains. No transcript was detected by Northern blot anlysis of homozygous mutant mice. Western blot analysis confirmed the absence of protein. (J:77207)