The primary pigment in the fur of common house cats is eumelanin, also known as the "black" pigment, though that is a little oversimplified, and it's only called that to distinguish it from phomelanin, or "red" pigment, which I'll cover in a different post.
Eumelanin comes in three distinct colors: Black (B), Chocolate (b), and Cinnamon (bl). Black is exactly what it sounds like, and is a pure black pigment. Chocolate is a plain but rich dark brown color. And Cinnamon is reddish brown and resembles, well, cinnamon.
Examples (all images found on google):
Black -
Chocolate -
Cinnamon -
Black is the dominant allele, so it is the most common color. So common, in fact, that most people have never even seen a chocolate or cinnamon cat. Which is a shame, because they're beautiful.
Chocolate is one rung down, recessive to black but dominant over cinnamon. Let's show a very simple punnet square:
In this scenario, we have two black parents, but they both carry an allele for chocolate. Therefore there is a 25% chance that a kitten will be chocolate instead of black (remember, it's a 25% chance for EACH KITTEN, not that 25% of the kittens will be chocolate).
Cinnamon is the ultimate recessive, and you need two cinnamon alleles to get a cinnamon kitten. Here's a slightly more complicated punnet square:
In this scenario, we have a black parent and a chocolate parent, but they both carry cinnamon.
Therefore, there is a 50% chance a kitten will be black, a 25% chance of chocolate, and a 25% chance of cinnamon.
That's all for this post! I'll cover the Dilute gene next.
this is all really interesting. learning stuff like this outside of class for the pure joy of it is way more interesting than any textbook ive ever read. you explained this really well!!