Mef2a^tm1Eno

The second coding exon was replaced with a neomycin selection cassette. RT-PCR confirmed the absence of normal transcript. While no normal protein was detected, a truncated protein was identified by Western blot analysis of homozygous mutant heart tissue. The mutant protein was translated from an aberrantly spliced mRNA in which exon 1 joined sequence downstream of neo. Gel mobility shift assays indicated an of ablation of endogenous DNA binding activity in homozygous mutant mice. (J:79973)