Col4a4^m1Btlr

The mutation has been identified as a G to A transition that impairs the donor splice site of intron 8. Reverse transcription of mRNA followed by PCR amplification revealed a deletion of 8 nucleotides in the transcript, resulting in a frame-shift that causes the addition after amino acid 176 of 13 aberrant amino acids followed by a premature termination codon. (J:158794) Additional incidental mutations were detected in sequencing for the causative mutation, Col4a4m1Btlr, and may be present in stocks carrying this mutation.