6.6kb genomic fragment containing the complete RNaseZ coding region plus 3kb upstream and 1kb downstream sequence. A single nucleotide mutation has been introduced into each of the three PAM sites targeted by RNaseZ^U6.3xsgRNA, so that this transgene is resistant to CRISPR/Cas9 targeting using RNaseZ^U6.3xsgRNA (the first nucleotide change (G to T) is in non-coding sequence, the remaining two changes (G to A and G to C) are silent mutations within the open reading frame). A T494I amino acid substitution has been introduced into the coding sequence. This change is equivalent to a variant that is linked with cardiomyopathy in the orthologous human gene. The coding sequence is tagged with Tag:V5.