When I first started in rabbits, I became fascinated by the colors and the genetics. It took a lot of reading and research, but I have learned a lot about how to determine potential color outcomes and genetics for my rabbits. The Vienna gene throws a bit of a wrench in it with the covering up, but its always fun to try to figure out what “real” color is hiding behind my BEWs.
Let’s start with basic genetics and go from there:
All rabbit’s genetics including color are made up with what we call a genotype. This is the “code” for the genes that make a rabbits color and determine the genetic output of that rabbit. Each set of genes (always in pairs) carries one genetic code from the Doe and one from the Buck. Depending on if they are dominant or recessive gene, some are easier to discern and others take time and breeding. The physical color shown on the rabbit and that we see is made up from the Phenotype which are the dominate genes that show through. Lets take a look at how this works. (Please note that basic rabbit colors are made up of genes represented by A-E lettering and we are only looking at “D” for this example).
Example: The Dilute gene:
d – Dilute
At this point you may be trying to remember what your high school science teacher told you about why some genes are capitalized and others lower cased. Well for most genetic purposes and to keep it simple for use non science people, the Uppercase is for a dominate gene and lower case for recessive. This works most of the time until you get into additional genes with multiple outcomes, but we will touch on that later.
So, let’s take a dense rabbit (Black) and look at what makes it “dense”. The black rabbit has two genes for this genetic makeup so it can either be DD or Dd. I know your going “what?”. How can it have two possibilities? Well the dominate gene is one “D” which will mask or cover up any recessive gene. So he could be carrying both dominate genes or he could be carrying a hidden recessive dilute gene.
See the above? One can carry the dilute gene while the other doesn’t and both are still “Black” with the one on the right just hiding that little recessive “d” waiting to pop up later in breeding.
Lets see what happens when we breed them both to a recessive Blue (dd) and show you what could happen.
With this pairing you would get Dd, Dd, Dd, Dd. That means all of the offspring will be Dense (in this case black), but carry the dilute gene hidden.
With this pairing above you would get Dd, Dd, dd, dd. You would end up with half dense carrying dilute and half dilute. (In this example, half black and half blue).
Now most times we can look at the pedigree and have a decent idea of what the rabbit carries for color based on parents and depending on the color itself (a dilute always carries “dd”). But if it is a dense and we aren’t sure about the hidden gene, you will show this as “D_” with the underscore representing an unknown gene.
Black Color in Rabbit: aaB_C_D_E_
I hope this brief tutorial was helpful. I will publish more on the individual genes as I get the time.