Ush1c^dfcr

The dfcr mutation is 12.7kb deletion of the 28-exon Ush1c gene. The deletion includes the last 118 nucleotides of exon 12, all of exons 13 - 15 and of alternatively spliced, inner ear-specific exons A, B, C and D, and 110 base pairs of the intron following exon D. The transcription product is spliced in all tissues examined so that exon 11 is joined, in frame, to exon 16 to produce an mRNA lacking exons 12, 13, 14 and 15 of the wild-type message, encoding 132 of the 548 amino acids comprising the ubiquitously expressed harmonin isoform a1. In the inner ear, an additional, minor splice product of the mutant transcript results from in-frame splicing of exon 11 to inner ear-specific exon E; this mRNA lacks 1137 nucleotides derived from exons 12, 13, 14, 15, A, B, C and D, encoding 379 amino acids of the wild-type inner ear-specific harmonin isoform b.Whole mount analysis revealed that the mutant protein is mislocalized to the very tips of cochlear stereocilia. (J:85400, J:157359)