Peafowl 201: Further Genetics- Colors, Patterns, and More

[Birdrain92]

[COLOR=0000CD]Definitely much more in depth than we ever got in college! But that was eons ago and I have tried to keep up but certainly can't. Just understanding the basics helps though. Thank you for continuously talking about it. I learn a little that way.[/COLOR]

Anytime.

 

[Dany12]

They say .... :

"A white bird may also be genotypically a purple bird, or a bronze bird, but the 'white' would mask these colors completely because the pigment for them would not be deposited on the feathers. Thus, a bird could genotypically be purple or bronze or any other color, but would phenotypically be white, and would breed true to white."


....I have an idea !


Opal pied X Opal pied = 25% Dark Pied Opal + 50% Opal Pied and ... and ...25% White.

Those White are in fact genetiquelly Opal !
They are Opal but White color !

The Opale mutation has two specific characteristics :
1 - the shape and size of the eyes.



2 - the top of the nape has short feathers like down feathers.




If what they say it's true, the white peacocks coming from Opale must have these characteristics!
It is very difficult to see it on white peacocks ... but on Pied peacocks !

The problem is that pictures of peacock Pied Opale are very ... very rare !

Have you a picture of a peacock Pied Opal?

 

[Midnightman14]

I had to catch up on this post a bit due to being absent for awhile but to address the red peafowl question there already are some reddish peas. The Red Buff birds are rust colored so they're about as close as we can get. A true red peafowl likely will never happen so the Red Buffs are as close as we'll get. Unfortunately since a Red Buff is just an interesting interaction between the BS gene and Spalding blood it doesn't breed true most of the time. As for the discussion on the Peach it's one of the 3 co-dominant split colors and is by far the easiest of the two to find. Hazel and Indigo are both still very rare due to them being non sex linked co-dominant splits. What makes them so hard to breed is that a bird cannot be truly split to indigo or hazel. When out crossing is done it takes 3 generations to produce more male chicks. The female Indigos and hazels will only comprise about 25% of the young in the 2nd generation cross. You can see how this makes establishing the colors a slow and confusing process.

 

[Dany12]

Red buff ... for sure came from green blood !

 

[Rosa moschata]

When a Purple hen was bred to a Cameo cock it produced an IB split to Cameo and Purple cock. Because it didn't have two of the same alleles it didn't show. Since the two alleles were not on the same chromosome, it wasn't split to Peach. When the cock was fertile, during Prophase I, the two homologous chromosomes bound together. While they were bound, Purple or Cameo was copied onto the other chromosome, cross over. Then when Meiosis was complete, 1 of the 4 sperm cells carried a Peach allele. Then when the sperm cell fertilized an egg cell with a W chromosome it produced a Peach hen. Then the cock was bred to the Peach hen, because one sperm contained a Peach allele, and the egg cell carrying a Z chromosome was Peach it produced a Peach cock. Purple and Cameo mixed together leads to Incomplete dominance creating a new color.

Your answer is not entirely accurate, and some terms are used incorrectly.

By definition, alleles are on the same chromosome because alleles are two versions of the same gene -- unless you're talking about the other homologous chromosome of the pair, as in one Z or the other Z, such as being heterozygous. But in any case, see next segment.

Purple and Cameo are not alleles, but they do both exist on the Z chromosome. An example of peafowl mutations which are alleles would be White and Pied. Peafowl with two White are White. Peafowl with two Pied are Dark Pied. Peafowl with one White and one Pied are "Pied". Yes, the terms peafowl breeders chose for phenotype and genotype are confusing, but that's how it works. As a result, a White can't be split to Pied, nor vice versa.

Don't refer to Peach as "an allele" or "a gene". It is not. It is the result of Purple and Cameo together on the same Z chromosome, which exist at separate loci -- two separate traits, two separate genes.

Incomplete dominance is not an accurate term to describe Peach. Incomplete dominance is when an individual is heterozygous at one particular locus, and both alleles show their effects together. It doesn't refer to being homozygous (or hemizygous, in the case of hens) for two separate mutations which are not alleles.

The general process which led to Peach is found within the essence of what you posted. I've posted it previously -- including earlier in this very thread, which I've linked below.


post #17

 

[casportpony]

@minihorse927, post 405 might interest you.

 

[WestKnollAmy]

Fascinating reading! Thanks for all the input, you all!

 

[Dany12]

Christopher ... if I say that the Peach mutation took place once ... and that not everyone can reproduce "this time" simply by mating a Purple cock with a female cameo?
There was a crossover?
My post 407 ... is logical ?

 

[Rosa moschata]

Christopher ... if I say that the Peach mutation took place once ... and that not everyone can reproduce "this time" simply by mating a Purple cock with a female cameo?
There was a crossover?
My post 407 ... is logical ?

"Peach" is not a mutation. It is the condition of being visual for both Purple and Cameo. Peach can certainly be recreated by crossing Purple and Cameo. To do so, take a male offspring from such a cross and breed him to a female of any color -- even IB. And it doesn't matter which parent is Purple and which is Cameo. Some of his daughters will be Purple, some Cameo, and a few either Peach or IB.

 

[Rosa moschata]

I'll explain further.

Cameo female X Purple male = Purple daughters and IB split to Purple and Cameo sons
Purple female X Cameo male = Cameo daughters and IB split to Purple and Cameo sons

Note that sons from both crosses will be the same for breeding purposes. Now take a son from either cross above and breed to an IB hen.

IB female X IB split to Purple and Cameo male

The daughters from the cross above will get their Z from only their father. As-is, their father has one Z with the Purple mutation, and the other with the Cameo mutation. Both are on the Z chromosome, but at different locations, or loci. Now, keep something else in mind -- the Z with the Purple mutation will also have the "normal" or "non-Cameo" version of the gene of which Cameo is a mutation, and the Z with the Cameo mutation will also have the "normal" or "non-Purple" version of the gene of which Purple is a mutation.

OK, so now to introduce the phenomenon of crossover. I linked the Wikipedia article on it because I don't want to repeat myself again out of consideration to those who have read my descriptions of it before. I do want to note that this is a known phenomenon and not some crazy made-up thing. It happens. We know it because it's been studied for decades.

So this IB split to Purple and Cameo male will be making some sperm. Each sperm has one member of each pair of chromosomes contained in his body cells, but which member of the pair will be random. And often, the chromosome will be a recombined version made from pieces of both pairs stitched together after crossover. If the Zs crossover at a point between the loci for the Purple and Cameo mutations, the result would be two newly recombined Zs -- one with both mutations, the other with neither. In other words, the original two Zs were one with Purple and "non-Cameo", and the other with "non-Purple" and Cameo. Recombined, you'd get one with Purple and Cameo (i.e. "Peach"), the other with "non-Purple" and "non-Cameo" (i.e. "normal IB").

OK, now let's get back to breeding the next generation.

IB female X IB split to Purple and Cameo male =
Daughters -- Purple, Cameo, IB, Peach
Sons -- IB split to Purple, IB split to Cameo, IB split to Peach, IB

I chose an IB female to focus on the only variable which concerns this discussion -- how Purple and Cameo together become Peach. As-is, the male above can pass on a Z with Purple or a Z with Cameo. Adding crossover possibilities, he can also pass on a Z with both Purple and Cameo (i.e. "Peach"), or a Z with neither Purple nor Cameo (i.e. "IB"). Because his daughters don't get a Z from their mother, her color in this situation doesn't matter.

How often will crossover occur at a point between the Purple and Cameo mutation loci? I don't know. It depends on the relative distance between the two points on the Z chromosome -- the greater the distance, the more places for crossover to occur between them. In other species, genes described as being "tightly linked" don't separate often because they lie close together on the chromosome -- thus less space for (and fewer chances of) crossover occurring between them. Considering the accounts of the original breeder of Peach, the two mutations aren't very close together, since the mutations came together in the first and second clutches.

You'll find some of my other ramblings on the inheritance of Peach by searching through old threads here. My former username was AquaEyes. I linked those discussions in the post below.

post #246