Dmd^mdx-3Cv

A T to A transversion creates a novel splice acceptor site 14 bp upstream of the natural site in exon 66. Splicing at this mutant site results in the inclusion of 14 bp of intronic sequence and shifts the reading frame of the encoded mRNA. While a low level of a smaller transcript is expressed from this allele, western blot analysis failed to detect any isoform of protein in various tissues from homozygous mutant mice (J:12150). However, a second report shows that the transcript generated by skipping exons 65 and 66 (D65/66) generates an in-frame transcript that produces low levels of dystrophin (J:250658). (J:12150, J:250658)