Fig 1. Genomic DNA sequencing chromatograms of regions of exons 5, 7 and 10 and splice site of intron 10 and putative branch site of intron 11 of the SLC7A9 gene from a healthy and cystinuric cats, and the amino acid sequence homology of the feline SLC7A9 gene among species and the site of missense variants (box).

The homozygous single nucleotide substitutions in exons 5, 7 and 10 are unique to the cystinuric cats and are predicted to change the amino acids from aspartic acid (Asp, D) to asparagine (Asn, N), valine (Val, V) to glutamic acid (Glu, E) and threonine (Thr, T) to methionine (Met, M), respectively. Additionally, a heterozygous and homozygous single nucleotide substitution are identified at the donor splicing site of intron 10 and putative branchpoint of intron 11 in two different cystinuric cats. Variants identified in cystinuric cats are bolded and the conserved areas among mammals are shaded.