Figure 2.

Tyrosinase (TYR) exon 2 tandem duplication in cats. (a) Schematic illustration of the TYR structure in genomic DNA and complementary DNA (cDNA) of a wildtype cat. Primer positions for RT‐PCR are indicated. (b) Splicing alteration in the mocha coated cat's cDNA is indicated. Duplicated areas of partial exon 2 are indicated by mocha‐colored blocks. Duplicated intronic regions are shown by solid red lines. Duplicated positions of partial exon 2 and the intronic region are indicated as NC_018732.3:45 898 609_45 898 771dup and by the bidirectional arrow. In the splicing process of TYR of the mocha‐coated cat, the normal exon 2 was skipped; however, the duplicated partial exon 2 and intronic 6 bp upstream (shown as red bold) are demonstrated to be transcribed due to the presence of the novel splice acceptor site (ag) (highlighted in yellow). The cDNA deletion region is shown by the bidirectional arrow and indicated as c.820_936. (c) Schematic illustration of cDNA TYR structure in deduced amino acids of a wildtype cat and a mocha‐coated cat. The domains are colored gray and annotated as SP (signal peptide), EGF (epidermal growth factor‐like domain), CuA (copper‐binding domain A), CuB (copper‐binding domain B) and TM (transmembrane domain). Several temperature‐sensitive TYR variants in mammals, including cats, are also annotated, and bars below each allelic designation is indicated by a black bar. The deleted region found in a mocha cat is colored orange. The dotted lines represent boundaries of each exon.