Figure 4. Sequence of the 3′ end of canine S-antigen messenger ribonucleic acid and the deduced translated protein. Uppercase plain letters=coding nucleotide sequence; lower case letters=3′ untranslated region (UTR); Uppercase bolded letters=deduced amino acid translation; Period (.) indicates Stop codon. Bold underlined lowercase nucleotides ( aataaa)=the polyadenylation signal. The sequence ends where a poly A tail was observed in X98460 messenger RNA (mRNA) deposited in the NCBI database. A: Sequence from a normal Basenji dog is presented. The normal stop codon (TGA) is codon 406. A single nucleotide polymorphism (SNP) (r=A/G) is observed in the 3′ UTR of normal dogs as indicated in bold italics. B: Sequence from a Basenji dog affected with progressive retinal atrophy (PRA) is presented. The red-boxed nucleotide (C) in panel B is the mutation that alters the normal stop codon (TGA) to code for arginine (R=CGA). Amino acids in red are the additional ones introduced by the nonstop mutation.