Figure 2. Gene Structures of Cat Tas1r3, Human TAS1R3, and Cat Tas1r2, Human TAS1R2 .

The exons are shown in black (size in bp of each exon is in parentheses). Boundaries of gene sequences used to produce probes for in situ hybridization studies (Figure 3) are shown by the horizontal lines labeled “P1” and “P2” under the sketch of the cat Tas1r3 and cat Tas1r2. Boundaries of sequence used to generate peptide antigens for immunohistochemical studies (Figure 4) are shown by the horizontal lines labeled “A” under the sketch of the cat Tas1r3 and cat Tas1r2. The locations referred to in the vertical explanation text above the asterisks and the spade symbol indicate the position in bp within each exon. Intron sizes shown in the figure are not proportionally scaled on both (A) and (B) because of the large size of Tas1r2 introns. Under each human exon is the percent similarity between each human exon and its cat counterpart at the nucleotide level (Figure 2B). The exons for cat Tas1r2 refer to parts corresponding to human exons. The spade symbol (♠) indicates the position of microdeletion in exon 3 of cat Tas1r2. Asterisks (*) indicate the stop codon positions in exon 4 and 6 of cat Tas1r2. Note that nucleotide numbers of the exon 3 in human TAS1R2 and cat Tas1r2 are not identical.