Recessive and/or Dominant genes...

[Miami Leghorn]

I would like to open this topic up with a couple of questions.
And I'm sure it will lead to others.

Are dominant colors dominant all the time?
Do/can recessive genes have the genetic potential that leads to a different color create changes in your breeding program due to undesired results?

In other words, if you are working with two chickens that have certain visible colors that you are using as a point of reference to either, maintain, develop, or change the resulting progeny's color, those would be I guess the dominant colors that are tangibly visible.
What about those that are not?
Would say, a rooster that shows a certain outer color has the genetic potential to derail your plans due to a recessive gene that can throw a wrench in your plans? Something that pops up unexpectedly?
Would say, a hen, that has undesired coloring have the genetic potential to hatch chicks with colors that are closer to what you want?

The reason why I ask is that I have a bit of experience with dogs and there are many cases where you would have a male or female that were from excellent performance bloodlines that were mediocre performers at best, but they, in turn, produced champions themselves. This is from a behavior standpoint I'm speaking of, not color, so I'm not sure if this applies to chickens and color.

 

[Ridgerunner]

Are dominant colors dominant all the time?

Yes but not really. There are different examples of that. Extended Black is the dominant color. It will trump Wheaten, Birchen, or anything else at that gene locus. But that does not mean you will always see black when it is present. The Barring gene can change a black feather to black and white or a red feather to red and white. Dominant White will modify a black feather to show only white but not affect other colors. Two copies of the B/B/S gene will modify a black feather to show Splash, while one copy if the BB/S gene will modify a black feather to show Blue. Again, this only affects Black feathers. Melanizers can turn red feathers black. Barring is dominant but you can't see it on a solid white chicken.

So while a dominant gene will trump a recessive gene, there are a lot of other genes in the mix that can modify a dominant gene.

Do/can recessive genes have the genetic potential that leads to a different color create changes in your breeding program due to undesired results? Would say, a rooster that shows a certain outer color has the genetic potential to derail your plans due to a recessive gene that can throw a wrench in your plans? Something that pops up unexpectedly?

Absolutely, happens all the time. It is hard to get rid of a recessive gene because you never know it is there hiding under the dominant gene. They can skip generations before they pair up.

There is a way to test that. If you have a bird that might be pure for a dominant gene or might be split for a dominant and a recessive, breed that bird to one that is pure for the recessive. Say Black and Wheaten. If you hatch several chicks and all are black, then the black parent is pure. If a wheaten chick shows up, then it is split. This may cost you a generation in your breeding program but you would know.

Would say, a hen, that has undesired coloring have the genetic potential to hatch chicks with colors that are closer to what you want?

In genetics anything is possible but some things are a lot more likely than others. Unless you know she at least has the potential for the recessive gene you are after I would not try it. Talk about shooting blind.

I have done that under controlled conditions. The mottling gene is recessive. I bred a mottled rooster to not-mottled hens. The pullets were not mottled, but when I bred them to a mottled rooster, about half the offspring was mottled. But breeding that mottled rooster to a flock of random hens, the likelihood of a mottled chick is highly unlikely.

 

[ChicKat]

Thanks for starting this thread Miami Leghorns. Ridgerunner, great insights in your post. This is going to be interesting!

Some folks have great patience with test breeding -- and as Ridgerunner states that is probably the only way to learn what is in any one particluar chicken that you yourself don't have the pedigree of from a long history of breeding the ancestors of that chicken -- and then there still could be hidden recessives. ALSO there are so many possible combinations of genes. Yikes.

Logically the genes that are visible are there. If it is a recessive like lavender -- only shows with two copies of the recessive you are home free...and if you do your own outcross or get splits from someone how keeps careful track, you know on that locus you have heterozygous for lavender. (One reason I like lavender -- it is obviously two recessive lavs when it shows up on the bird.)

In UK -- they have a specific bird --( I'll see if I can find my seminar notes), that they use to test another bird. I think it is wildtype -- which would show all the "non-mutated" genes. Pair that bird with the one you want to find out what it has -- and what shows up that is not Wildtype would at least show the dominant genes in a single copy in the case of the next generation. Or extrapolating from that...pair the one you are wondering about with one lacking that trait completely and check the chicks. I guess that is pretty much just another way of repeating something Ridgerunner said. LOL

There's a lot to this topic.

 

[Ted_Harrell]

Fascinating..

 

[ChicKat]

Okay, went through the hand out from the March 2014 Genetics seminar that Grant Brereton had in Morganton NC, and didn't locate a reference to this basic bird -- somehow I think it was a silkie..? I'll look again later. Maybe it was a bird that had none of the wild-type genes and all of the mutations or a lot of the mutations to help detect what a particlular chicken is carrying.

There was one interesting point that struck me on this though. It was a discussion of mating brothers to sisters. Someone with a prize winning line of Blue German Langshan Bantams mated a splash parent to a black parent. The result was all blue chicks. If one of the parent birds were to be lost and this particular strain of birds was the world's best hands down...by the owner doing a brother-sister pairing the results would be 50%blue chicks, 25% black chicks and 25% splash chicks. Then from that set, one could be chosen and bred back to the remaining surviving parent -- for example if the splash had been killed, another splash could be paired with the parent bird that was black and then all blue offspring with the good genetics of that breeder's strain would be continued.

Grant Brereton also said in the handouts
"The sibling mating is carried out to release recessive genes or purify dominant ones. In this case, it would be to purify the incompletely dominant blue Blue gene and hence produce some splash breeding birds. Ironically to avoid having splash in future generations" i.e if the breeder had only blue to blue to breed some chicks would always be unacceptable.

Google for any articles on the internet you can find by Grant Brereton -- it's a good way to learn a lot.

 

[Miami Leghorn]

Time for coffee and note pad. You guys are dropping some quality information here...

 

[Ted_Harrell]

I know right...