Feline Genetics: Dilution

Hello all!

The next part to learn about feline genetics is a rather simple one. This is dilute. Okay, so what have we already learned? We've learned black factor, which is black, chocolate, and lilac. The dilute gene basically "washes out" the base color. This is determined by the allele labeled with D. Now, dilution is a gene that is either displayed or not. The other version of dilution is solid. The technical, genetic term for solid is dense. So a cat is either dense or dilute.

So what does this mean for our cats? At the most basic level, it boils down to this.

Now I know we haven't discussed red or cream tabbies yet, so I'll be mentioning them again when it comes time to learn that! So how do we know what kind of outcome there is for the litters? We do two punnet squares. Let's take a chocolate father with a blue mother. So we know that chocolate can be bb or bb^l and it is a dense, so we know that it can be DD or Dd. We also know that blue can be BB or Bb and it is dilute so it must be dd. To further get into it, we need to know the parents of the parents. But since we can't trace it back, let's assume the chocolate is bb and Dd and the blue is BB and dd.

This tells us 100% of the offspring will be Bb, or black base.

This tells us the 50% of the offspring will be Dd, or dense, and 50% of the offspring will be dd, or dilute. Now it's random chance what two will pair with the other two. But since the first outcome is all Bb, we can assume that 50% of the offspring will be BbDd and 50% of the offspring will be Bbdd. That means 50% will be black carrying both chocolate and dilute and 50% will be blue carrying lilac (because blue and lilac are dilute).

Blue

(Image by Jans Canon, found at Flickr.com)

Lilac

(Image by libodyssey, found on Flickr.com)

Fawn

(Image by Chris Pearson, found at Photobucket.com)