Ctbp1^tm1Sor

The exon encoding amino acids 55 through 102 was replaced with a floxed neomycin selection cassette. RT-PCR and sequence analyses showed that the disrupted exon was excised and the resultant splicing of the adjacent exons introduced a frameshift mutation. The absence of protein was verifed by Western blot analysis of lysates obtained from homozygous mutant embyros. (J:77905)