diffrence between cuckoo and barred

[Chris09]

The gene that makes good clean barring on any Barred bird is the Slow Feathering Gene (K), the Barring gene (B) is just a on off switch.

Barring Gene: B
Barring is a Sex-link gene that stops and starts pigment production as in feather growth to give the well-known barring pattern as seen on Barred Rocks. The extremely narrow and sharp barring seen on the Barred Plymouth Rocks is achieved by the presence of the gene (K) for very slow feathering growth, which allows for a lot of on/off sequences in the time it takes for a feather to grow. The same barring gene ('B') when on a rapid feathering breed gives wide, coarse, fuzzy "Cuckoo Barring" as seen on Cuckoo Marans, Cochins, Dominique and others. The barring gene also interacts with the gene on the E locus, all of the above examples being based on the E locus plus melantoics. Thus all these barring and cuckoo breeds would be self-black if they did not have the barring gene. This gene has greater pigment-restricting effect on black pigment than it does on red or gold pigment. When the barring gene is applied to the Wild Type pattern, the Crele variety is produced; and the barring on Columbian pattern combination is seen on Rhodebars, one of the autosexing breed


Chris

 

[centrarchid]

We need to stress more than one loci is slowing feather growth in many breeds; and that they may be additive. Relative to American games, dominques are slow feathering even though in most instances the latter is not considered to be slow feathering, especially when compared to other dual purpose or meat production breeds. Even the slow slow feathering can be sex-linked as evident in the feather sexable hatchery lines.

 

[Chris09]

Quote:
The order of dominance among the genes. (first is more dominate than last)
K^n - very slow
K^s - slow
K - late
k+ - rapid feathering

Chris

 

[centrarchid]

Quote:
The order of dominance among the genes. (first is more dominate than last)
K^n - very slow
K^s - slow
K - late
k+ - rapid feathering

Chris

Chris,

As written above, only one locus with four alleles is involved. There are at least two loci.

 

[Chris09]

Quote:
The order of dominance among the genes. (first is more dominate than last)
K^n - very slow
K^s - slow
K - late
k+ - rapid feathering

Chris

Chris,

As written above, only one locus with four alleles is involved. There are at least two loci.

Do you have information on the other loci ?

Chris

 

[Sonoran Silkies]

Maybe he meant that each bird has two genes? I'm only aware of one gene (locus) related to feathering rate, but each bird has two copies. So a K^n/K^n bird might have better barring than a K^n/k+.

 

[Chris09]

Quote:
Now that might be.

Chris

 

[centrarchid]

Quote:
Chris,

As written above, only one locus with four alleles is involved. There are at least two loci.

Do you have information on the other loci ?

Chris

One is the sex-linked version used in sex-linked populations where males feather out slower.


Evidence for second autosomal locus may be causing the greater number of feather rate morphs popping up in my dominique crosses. No hard evidence there. It may be simple such as the typical autosomal locus may have been duplicated and has some or all of same alleles as the first you already indicated.

 

[Chris09]

Quote:
Do you have information on the other loci ?

Chris

One is the sex-linked version used in sex-linked populations where males feather out slower.


Evidence for second autosomal locus may be causing the greater number of feather rate morphs popping up in my dominique crosses. No hard evidence there. It may be simple such as the typical autosomal locus may have been duplicated and has some or all of same alleles as the first you already indicated.

There is Barring as seen on a Barred Rock, Cochins, and Dominique then there is Autosomal (non-sex-linked) Barring like what is found on Hamburg and Campine chickens.
Could that be what you are talking about?


Chris

 

[centrarchid]

I am referring to loci influencing rate of feather developement.


Autosomal loci you indicate with alleles as follows.
K^n - very slow
K^s - slow
K - late
k+ - rapid feathering

The Z-chromosome version with alleles as follows.
Kz^S - slow feathering
kz+ - rapid feathering

Male of feather sexable lines has double dose of Kz^S - slow feathering while female has only one. Affect is additive so male has slower developing feathers than female siblings. Female with only one copy of Kz^S / w-chromosome still has slower feathering than either kz+ / kz+ male or kz+ / w-chromosome female.