Are Combs and Wattles Genetically Linked?

[sjango]

This is something I've been curious about for a while. Is the expression for the appearance of the comb and wattle on the same loci, or are they separate genes?

 

[NatJ]

I am assuming that single comb is the default, and that everything else is different (or not different) compared to that.

The pea comb gene changes the shape of the comb, and two copies of the pea comb gene makes both comb and wattles smaller.

Any gene that affects comb color will affect wattle color too (like in Silkies, with their black skin.)

Muff/beard makes the wattles smaller, but does not affect the comb. (One gene, causes both muffs on the sides of the face and beard under the chin.)

I do not think the wattles are affected by the gene for rose comb or the genes for either form of duplex comb (V or Buttercup). V-comb changes the shape of the chickens' nostrils, Buttercup does not.

If you stack up multiple comb genes: any combination with two copies of pea comb should get the reduced wattles, but the comb may look different depending on what other genes are present. Walnut, strawberry, and cushion are all names for combs that are rose + pea. I don't think there is a specific name for duplex comb combined with rose or pea or both, and it's certainly not common.

 

[sjango]

I am assuming that single comb is the default, and that everything else is different (or not different) compared to that.

The pea comb gene changes the shape of the comb, and two copies of the pea comb gene makes both comb and wattles smaller.

Any gene that affects comb color will affect wattle color too (like in Silkies, with their black skin.)

Muff/beard makes the wattles smaller, but does not affect the comb. (One gene, causes both muffs on the sides of the face and beard under the chin.)

I do not think the wattles are affected by the gene for rose comb or the genes for either form of duplex comb (V or Buttercup). V-comb changes the shape of the chickens' nostrils, Buttercup does not.

If you stack up multiple comb genes: any combination with two copies of pea comb should get the reduced wattles, but the comb may look different depending on what other genes are present. Walnut, strawberry, and cushion are all names for combs that are rose + pea. I don't think there is a specific name for duplex comb combined with rose or pea or both, and it's certainly not common.

Thank you so much! I couldn't find this kind of info anywhere.

 

[NatJ]

Thank you so much! I couldn't find this kind of info anywhere.

I've been picking it up in bits and pieces for some time now. I don't think I've ever found it all neatly in one place, though.

Maybe it's because there are so few things that do affect wattles (beards and pea combs and skin color), so they tend to get overlooked or ignored.

Another comb-gene effect I neglected to mention:
Rose comb causes reduced fertility in roosters, but only for homozygotes (two copies of the rose comb gene). Heterozygotes (one copy of the rose comb gene) have the same appearance, but normal fertility. The effect only matters when you have large numbers of hens per rooster, so commercial raisers would care but most other folks don't.

http://www.edelras.nl/chickengenetics/mutations2.html
Plenty of interesting information there, but it can be a bit much to wade through unless you really like that kind of stuff.