I have to admit that I’ve been really nerding out lately. Sorry, this post isn’t about denim, but rather genes. (See what I did there??). I absolutely love poultry genetics, especially when it’s regarding their color. With the impending breeding season coming in a few months with the guinea bugs, I’ve been quite curious what I’ll be getting if the different colors cross with each other now that I have 4 different colors. I figured it’d be interesting to my fellow aspiring geneticists (ha!) to make a few posts about it as I learn more. Keep in mind, this is MY understanding, and while it probably is correct, take my information with a grain of salt. I can be wrong and am allowed to be wrong. And if you have helpful information, I’d love to hear it! The only way I can prove what I have figured is to breed my birds and keep track of what I get. This is also my way of learning as I go. By typing these posts, I’m mapping their genetics out in my mind and putting it down to share with others that are wondering the same things I am…
I currently have Pearl Grey, Coral Blue, Lavender, and Buff Dundotte guineas. Therefore, these are the color patterns I am focusing on. I am also assuming at this point that none of the genes are sex-linked (meaning different expressions between males and females). What I really want to know is what will happen if these colors mix amongst each other, as in a Coral Blue breeds a Buff Dundotte.
First, when trying to figure out the possible phenotype and genotype of the first generation of keets is to understand what the underlying genotype of the parent birds is and also to understand what phenotype and genotype mean.
Phenotype: the physical appearance of the bird. You can see this.
Genotype: the genetic make-up of the bird. You cannot see this.
By looking at Cato, my Pearl Gray guinea male in this picture, I see that he is gray in color with white spots. This is his phenotype. Genetically, I know that he is a pure Pearl Gray guinea, meaning his parents were pure Pearl Grays and were not mixed with another color. Pearl Gray is considered the dominant color of all guineas, because if Pearl Gray is crossed with any other color, only Pearl Gray will be seen in the first generation.
I used Punnett Squares to help me cross my different colors of birds to find the genotype and then interpret phenotype of possible cross-pairings. I used the most basic genotypes (color and pearling) to use in the Punnett Squares, because I’m not going to do the 64×64 square one to guess leg coloring and wattle size and eye color, etc. Right now, I just don’t care about those things. I want the basic feather coloring and pearling. When figuring genotype, I use capital letters for dominant genes (AA) and lower-case letters for recessive genes (aa). There are three possible pairings between alleles:
- Homozygous dominant (AA): there is two copies of the dominant gene, meaning the parent will always give their offspring a dominant gene.
- Heterozygous dominant (Aa): there is one copy of the dominant gene and one copy of the recessive gene, meaning the phenotype will always show the dominant gene but the parent may pass either a dominant or recessive gene to its offspring. In the poultry world, this is also called a “split.”
- Homozygous recessive (aa): there is two copies of the recessive gene, meaning the recessive gene is expressed and a recessive gene will always be passed to the offspring but not necessarily expressed.
The two main things I am considering with my guineas are their background color and their pearling. The amount of pearling that a guinea has affects their background color. The main background colors I am dealing with in my guineas are gray, blue and buff:
- Gray (GG) is dominant and can be expressed homo- or heterozygous
- Blue (bb) is recessive and is only expressed homozygously
- Buff (uu) is recessive and is only expressed homozygously.
- Blue/Buff (bu) is a mix between a blue and buff bird that possibly creates the color opaline (buPP, buPp) and porcelain (bupp) depending on the pearling (PP, Pp, or pp).
As for pearling, there are three options:
- Pearled (PP) means the guinea is fully pearled with prominent “white spots”
- Semi-pearled (Pp) means the guinea has pearling but it is not prominent
- Non-pearled (pp) means the guinea is a solid color with no spots
Thus far, I am unsure about the semi-pearled, if it is expressed as such, since my only semi-pearled birds are my Coral Blues. My assumption is, if a bird is Pp rather than PP, they will appear much darker in contrast to the full pearled since they have less white spots on their feathers, which is true when comparing my Lavender guineas (PP) to my Coral Blues (Pp). The Corals are a much darker blue color in contrast.
How interesting is this?
Betcha can’t wait for the next post?