An
example of how genes can affect the patterns in cat fur is a pattern
known as Agouti. Some cats have different colored bands along the
shafts of their tails, and the gene that causes this pattern is the
“Agouti Signaling Protein,” and a mutation or change in this gene
can have drastic affects on the pattern in a cat's fur. The banding
is based on the dominance of the Agouti gene and occurs when a cat
carries one or two copies of the gene. When the banded fur and solid
fur alternate, it is called tabbying, which is common in many cats.
If a cat has two copies of the non-agouti gene, then the fur will be
solid. In most tabby cats, the stripes are defined and evenly spaced.
There is also the tabby gene, as well, that effect the pattern. There
are three different stripe patterns which are inherited through the
tabby gene: Mackerel, Classic, and Abyssinian. A mutation in any of
these genes can cause variations of those patterns.
Tabby patterns only show up when cats begin to grow
hair, which is within their first seven weeks of gestation, carried
out while the embryo develops, by changing levels of Edn3. During
gestation, levels of Taqpep increase. The Taqpep mutation happening
earlier on in a cat's life may determine why spots and stripes don't
change as the cat grows older. The main researcher in the study
speculated that the gene has other functions, and may do more for the
cats than simply change their patterns, such as helping boost
immunity against disease and infections.