Peafowl Genetics for Dummies (in other words us)

[Arbor]

It's not that I disagree with either of you, just that the question would come up eventually. I figured to ask to bring the question forth as a learning opportunity. The current Spalding charcoal hens are not 50/50 splits, and are likely higher % spaldings, therefore leading one to believe multiple generations of breeding with several genetically varied birds may have lead to this. The more we breed this colour ,the more it should be stressed to use stock that is as far from related as possible.

Perhaps the genes associated with fertility in hens is close in proximity to those which affects colour.

 

[Rosa moschata]

It's not that I disagree with either of you, just that the question would come up eventually. I figured to ask to bring the question forth as a learning opportunity. The current Spalding charcoal hens are not 50/50 splits, and are likely higher % spaldings, therefore leading one to believe multiple generations of breeding with several genetically varied birds may have lead to this. The more we breed this colour ,the more it should be stressed to use stock that is as far from related as possible.

Perhaps the genes associated with fertility in hens is close in proximity to those which affects colour.

You're assuming the "one gene, one effect" idea which is not true in many cases. In fact, it is well-known that genes have multiple effects (i.e. pleiotropy), and that was my point about discussing Charcoal -- we may think it's just a color mutation, but the very same gene mutation (rather than another independent mutation which just so happened to occur at the same time in a different but nearby gene, which is far less likely) can also be the cause of the infertility issues in the India Blue species. For whatever reason, the gene may not impart the same problems in the various Green species' mix of genes.

 

[AugeredIn]

....From all I've read, Silver Pied X Silver Pied does not result in 100% Silver Pied, but rather three different phenotypes assorted into the classic 1:2:1 ratio of a monohybrid cross. OK, so you many say that's because they need to be heterozygous White/Pied. Well, that alone tells you it requires more than one gene -- not counting White Eye. As a result of observing that pattern of inheritance, the Silver Pied phenotype is NOT the result of one gene mutation. There may be an additional gene in the mix which adds the "silver sheen" but there is no one, single gene which gives rise to the Silver Pied phenotype. That's my point.

I do not refer to silver pied as a single gene pair phenotype. I agree with the above and postulate that if there is truly a difference between a phenotypically pied white eye (one pied, one white, two white eye genes) and a phenotypically silver pied bird (one pied, one white, two "silver pied" genes) then silver pied must be an allele with white eye based upon phenotypes.

 

[Rosa moschata]

I do not refer to silver pied as a single gene pair phenotype. I agree with the above and postulate that if there is truly a difference between a phenotypically pied white eye (one pied, one white, two white eye genes) and a phenotypically silver pied bird (one pied, one white, two "silver pied" genes) then silver pied must be an allele with white eye based upon phenotypes.

But why add confusion by giving a name to a hypothetical gene that's already being used to describe a multiple-mutation phenotype? You agree that Silver Pied is not a single-gene phenotype, but then want to discuss the possibility of a "silver pied gene". Perhaps call it the "silver sheen gene" or "dusting gene" or something else. Otherwise, if it actually exists, you'll make things even more confusing, because people will learn about the "Silver Pied gene" and think that's all that's needed to turn an India Blue into Silver Pied -- and then come here asking why their "split to Silver Pied" pair don't get the expected 25% Silver Pied offspring.

 

[connerhills]

In the 2012 year I bred a Bronze male that had no white but did produce WY offspring to a Blue female split to Bronze and Silver pied, All I got were some Bronze females and some splits to Bronze. Last year this same breeding produces a few Bronze hens and 2 males ,one started out with some WY indications and at 8-9 months is all Bronze.. The other one has a lot of white and getting more a lot more,, I have discussed this with some other breeders and the thoughts is that this bird is like what is being called a progressive pied, but the pied is not coming in like a normal pied does. He is, as I stated less than 1 yr old. Some where I have the reported background of the Bronze and there is a cross of green into them and I think that is what give it the green sheen in the neck. connerhills

 

[Arbor]

You're assuming the "one gene, one effect" idea which is not true in many cases. In fact, it is well-known that genes have multiple effects (i.e. pleiotropy), and that was my point about discussing Charcoal -- we may think it's just a color mutation, but the very same gene mutation (rather than another independent mutation which just so happened to occur at the same time in a different but nearby gene, which is far less likely) can also be the cause of the infertility issues in the India Blue species. For whatever reason, the gene may not impart the same problems in the various Green species' mix of genes.

I assume nothing, it makes us both look bad. I misused the word gene. What I meant to say was perhaps the sequence of DNA bases that effect colour include those that could effect fertility in some way in charcoal hens. Multiple bases changed at the same time within the sequence could cause this.

 

[Rosa moschata]

In the 2012 year I bred a Bronze male that had no white but did produce WY offspring to a Blue female split to Bronze and Silver pied, All I got were some Bronze females and some splits to Bronze. Last year this same breeding produces a few Bronze hens and 2 males ,one started out with some WY indications and at 8-9 months is all Bronze.. The other one has a lot of white and getting more a lot more,, I have discussed this with some other breeders and the thoughts is that this bird is like what is being called a progressive pied, but the pied is not coming in like a normal pied does. He is, as I stated less than 1 yr old. Some where I have the reported background of the Bronze and there is a cross of green into them and I think that is what give it the green sheen in the neck. connerhills

OK, I'll bite. What, genetically, is a "Blue female split to Bronze and Silver Pied"? If Silver Pied requires one copy of White, and one copy of Pied, along with the White Eye mutation, AND the hypothetical "dusting" gene, and you say your hen that is "split" to all of that, what is she? She can't have a copy of White and a copy of Pied and not BE Pied, so she has one or the other. If two of the ingredients to put together the Silver Pied phenotype are alleles, she can't be split to both and ALSO have a "normal" version of the gene -- unless she's triploid.

Let's just assume she had one Silver Pied parent, and one Bronze parent -- which, if you want to use "Silver Pied" as though it was one gene, would result in a bird being "split to Silver Pied". Genetically, however, she'd be either:

1) IB single factor White Eye split to Bronze and White

or

2) IB single factor White Eye split to Bronze and Pied

Let's focus on the Pied/White part. Being as both Pied and White are necessary ingredients to make the Silver Pied phenotype, a bird technically can't be "split to Silver Pied" because that implies having one copy of each ingredient, balanced with the normal version of each. If she has one copy of White and one copy of Pied, she wouldn't be IB split to White, or IB split to Pied, or IB split to White and Pied. She'd be IB Pied. And with two different versions of the same gene, there's no third "space" left for the normal version to occupy -- again, unless you have a hen with three sets of each chromosome, i.e. a triploid bird.


This is why using phenotype names in genetic equations leads to confusion -- and why the same "what do I get if I cross...?" questions keep coming up on here. You might very well know what you mean when you say something like "split to Oaten" but the term itself is not clear.

 

[Rosa moschata]

I assume nothing, it makes us both look bad. I misused the word gene. What I meant to say was perhaps the sequence of DNA bases that effect colour include those that could effect fertility in some way in charcoal hens. Multiple bases changed at the same time within the sequence could cause this.

haha!

 

[Arbor]

I wonder if a second pied mutation occurred to allow for the frosting in silver pied? I've heard that several people have tried to replicate silver pied by trying to breed for W/P/we/we, with no success. Perhaps a change in bases on the gene for pied has allowed for this?

 

[AugeredIn]

Rosa, I feel you are so focused on my use of silver pied both as a phenotype and gene mutation description that you may be missing my point. From this point on I will use silver pied only to describe a bird that is pied with all white eyes but has silver saddle feathers instead of the base color.

First, connerhills and others are saying that there is a difference between a pied white eye bird and a silver pied bird.

Second, I am saying there is an allele to the white eye mutation and lets call it the silver white eye mutation.

Therefore, a bird with one white, one pied and two white eye genes is pied white eye (this bird has saddle feathers the same as the base color). A bird with one white, one pied and two silver white eye genes is a silver pied.

connerhills, do you get what I am saying?