Chicken Genetics 101

[nicalandia]

More info on the subject from a few posts made by me from 2012, post direct link: https://www.backyardchickens.com/th...andotte-with-single-comb.714166/#post-9749762

its a "Well known" secret that some lines of Wyandottes are not pure for the Rose Comb gene, breeders do this on purpose, there is only one main reazon some breeders do this, and its because pure Rose Comb birds(R/R) have lower fertility rate than Heterozygous Rose Comb Males(R/r+) http://www.ncbi.nlm.nih.gov/pubmed/8072931 and there is the fact that the Rose Comb gene is one of the few completely dominant gene, what does this means? it means that you cant tell apart a heterozygous rose comb rooster(R/r+) from a Homozygous Rose Comb rooster(R/R) so some single comb wyandottes are to be expected...

Post Direct Link: https://www.backyardchickens.com/th...andotte-with-single-comb.714166/#post-9750344

Source
http://www.genetics.org/content/48/9/1141.full.pdf

So Far, Single Comb, Pea Comb and Rose Comb have been identified as simple autosomal genes, where Single comb is p+/p+, r+/r+. Pea comb is P/P, r+/r+ and Rose Comb is R/R, is only when you combine both dominant mutations P/P, R/R when you get what is called Walnut comb!

 

[Brahma Chicken5000]

@nicalandia you mentioned that the rose comb gene has been linked to low sperm mobility and low fertilization in rose comb breeds like Wyandotte, Sebright, and the Rose Comb Bantam. Do Dominiques have this problem too? I’ve never heard of a single comb sport Dominique.

 

[Amer]

@nicalandia you mentioned that the rose comb gene has been linked to low sperm mobility and low fertilization in rose comb breeds like Wyandotte, Sebright, and the Rose Comb Bantam. Do Dominiques have this problem too? I’ve never heard of a single comb sport Dominique.

Actually, it does have this problem. Though you have never seen one, they do exist as well. Usually, Dominique breeders are responsible though and only use them in breeding, while Wyandottes are a more popular hatchery breed, so the single combs pop up.


D'Anvers also would probably have low fertility, but their aggressiveness prevents it.

 

[Brahma Chicken5000]

Leg feathering is usually dominant.
Clean legs are usually recessive.

What letter(s) represent it?

 

[Amer]

What letter(s) represent it?

Idk. That's the problem.
Unfortunately, leg feathering is also somewhat polygenetic.
Kip calls it "Pti" I guess.

 

[Brahma Chicken5000]

Incomplete Dominant Muffs & Beards are represented as (Mb).
Birds lacking Muffs & Beards are (mb+).
So what are birds like Ameraucanas that have full Muffs & Beards? (MB)?

 

[Brahma Chicken5000]

The presentation was a hit! Thank you all for your help!

 

[Amer]

You're very welcome!

 

[renk777]

Hijacking thread just because I'm up at 2 AM and got to thinking... I have a barnyard mutt roo I'm rehoming. The thing is, i really want to keep him for a number of reasons but to keep this short, I won't list them. He's out of a blue/blue-green/green egg and has black skin. I confirmed Ayam Cemani run in flock but couldn't get any more info out of seller. She just didn't know what cross(es) produced him or the other chicks she hatched with him. Both pullets are similar in size and had dark down. One is white skinned; the other is black. I'll include a pic of the three now and as chicks. If I were to cross the roo with these pullets and also cross him with our blue partridge brahma (to increase body/egg size and get feathered feet), what might the resulting birds look like? (Not including pic of brahma because I assume you probably know genetics on her). Roo is predominantly white, ivory, and black but there is brown in some of his feathers. Girls are similar is size/shape but I do not know if they share parents. He's just so unique. Would I get just a big pile of ugly or something really cool?

 

[nicalandia]

The rooster is confirmed id+/id+(if he had a copy of Id his skin would have been White) he has atleast one copy of the Fibromelanotic mutation(Fm) seems to be golden(S/s+) and Birchen(ER) with Columbian. The white skin hen is id+/- fm+/fm+, the one with black skin is Fm/fm+ id+/-.

When crossed with those hens you get 50% chance of getting more black skin birds, when crossed with the Brahma hen you have 25% chance of getting black skin birds(50% of the pullets, the other 50% of pullets will be white skin and 100% of males will be white skin)