a) Protein sequence, b) DNA sequence. The letters on the top line are the single letter codes for amino acids, for example, a P is proline, an N is asparagine, an R is arginine, and a G is glycine. The top line is the sequence for a normal, non-pointed cat. The second line is the sequence in humans, the third is the Siamese-pointed cat, and the bottom line is the sequence for the domestic dog. c) A Dominant white Siberian cat with yellow eyes had one allele for points but the other allele had a normal DNA variant. This variant did not change the amino acid, this is silent. A genetic test that incorporates this sequence surrounding the mutation for points may fail in some cats, producing allelic drop-out. The cat would have a result of homozygous for points. All pointed cats must have blue eyes, thus, this variant was identified and the genetic assay changed to account for this possibility in the flanking genetic sequencing.