Can anyone explain genetis of the comb, which one is the dominant one and what co-dominant one means?

[Nenad]

Which of I guess 6 types of combs is the dominant to other 5 and what is recessive or least dominant? What is co dominant mean? Thanks

 

[pipdzipdnreadytogo]

Both rose and pea combs are dominant over single combs. Rose combs are completely doimnant over single combs, while pea combs are partially dominant over them. With one pea comb gene, you see taller pea combs that may even resemble a single comb with bumps on the sides, while with two genes you see smaller pea combs that are closer to the head. With either one or two rose comb genes, you get a rose comb. The pea comb gene also reduces the size of the wattles, whereas the rose comb gene does not. A bird with both pea and rose comb genes has a walnut comb.

There is also a gene that smooths out the comb, causing fewer serrations in single combs and causing smooth rose combs versus spiky rose combs. A walnut comb plus this smoothing gene causes a cushion comb. I do not know the dominance of this gene off hand.

V-combs and buttercup combs are related genes, both alleles at the duplex comb locus. I don't know if I fully understand their dominance, but from what I understand, both are incompletely dominant to single combs. When you cross a V-comb to a single comb, you get something that outwardly looks like a small buttercup comb, but is genetically different. When you cross a buttercup comb to a single comb, you get a single comb that splits at the back. V-comb is apparently completely dominant to buttercup comb, so V-comb to buttercup comb makes combs that outwardly look like V-combs.

I don't know anything about carnation combs, honestly. There's also a combless gene found in Breda, which I believe is recessive to all other comb types. I believe single combs are the least dominant besides the combless gene.

Edited to remove something I misremembered about​

 

[Nenad]

Codominance is basically when two genes express at the same time to produce something different than what those genes would produce on their own. Walnut combs are an example of this; they're a result of both rose and pea comb genes being expressed.

Both rose and pea combs are dominant over single combs. Rose combs are completely doimnant over single combs, while pea combs are partially dominant over them. With one pea comb gene, you see taller pea combs that may even resemble a single comb with bumps on the sides, while with two genes you see smaller pea combs that are closer to the head. With either one or two rose comb genes, you get a rose comb. The pea comb gene also reduces the size of the wattles, whereas the rose comb gene does not.

There is also a gene that smooths out the comb, causing fewer serrations in single combs and causing smooth rose combs versus spiky rose combs. A walnut comb plus this smoothing gene causes a cushion comb. I do not know the dominance of this gene off hand.

V-combs and buttercup combs are related genes, both alleles at the duplex comb locus. I don't know if I fully understand their dominance, but from what I understand, both are incompletely dominant to single combs. When you cross a V-comb to a single comb, you get something that outwardly looks like a small buttercup comb, but is genetically different. When you cross a buttercup comb to a single comb, you get a single comb that splits at the back. V-comb is apparently completely dominant to buttercup comb, so V-comb to buttercup comb makes combs that outwardly look like V-combs.

I don't know anything about carnation combs, honestly. There's also a combless gene found in Breda, which I believe is recessive to all other comb types. I believe single combs are the least dominant besides the combless gene.

Thank you so much, It really helped me out.

 

[Nenad]

Thank you so much, It really helped me out.

I don't want to look like a short answer to your answer but I really appreciate this

 

[pipdzipdnreadytogo]

Haha, you're fine! I'm glad I could help!

 

[Amer]

Actually, none of the comb genes are co-dominant. Rose and pea combs are caused by separate genes, not just separate alleles. Both genes in the same bird cause walnut combs.
Codominance is expression of both genes on different parts, it would have to be one part of the comb is rose and another is pea, caused by one heterozygous gene. Which would be a bit odd looking. Paint is an example of codominance with dominant white.
Incomplete dominance is a perfect blend of two alleles, like the duplex comb allele with the single comb allele.

 

[Amer]

Other than that, you got it all right. I actually had to look up codominance to make sure I was using it correctly because I mix it up with incomplete dominance.

 

[pipdzipdnreadytogo]

Actually, none of the comb genes are co-dominant. Rose and pea combs are caused by separate genes, not just separate alleles. Both genes in the same bird cause walnut combs.
Codominance is expression of both genes on different parts, it would have to be one part of the comb is rose and another is pea, caused by one heterozygous gene. Which would be a bit odd looking. Paint is an example of codominance with dominant white.
Incomplete dominance is a perfect blend of two alleles, like the duplex comb allele with the single comb allele.

Oooh, you're right, I was not remembering correctly. Too many years since genetics class!