Leucistic genes in peafowl

Discussion in 'Peafowl' started by Garden Peas, Nov 21, 2014.

  1. Garden Peas

    Garden Peas Chillin' With My Peeps

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    Okay, this is a topic that has fascinated me for a long time, and I've read lots of different opinions over the past several years. I thought I more or less understood what appeared to be the general consensus on silver pied birds...

    Appearance-wise -- 80-90% white, plus white eye

    Genetically -- white gene plus pied gene plus white eye gene(s) -- some folks say TWO white eye genes are needed.

    And perhaps the white "needs" to be a white from a white-eye bird...

    The clearest thread I ever read on it is here:

    https://www.backyardchickens.com/t/571197/inheritance-of-silver-pied

    But then -- oh my -- I joined BYC a few months ago and suddenly started reading about "silver dusting" -- and there doesn't seem to be a lot of consensus about it.

    In the thread I linked above, there is some mention that perhaps silver dusting results from having two copies of the white eye gene, but I don't know whether that has been verified.

    It seems to me that another possibility is that there is a variant white eye gene mutation, or possibly another leucistic gene which causes that silver dusting. Or maybe it really is just the two white eye genes working together.

    If two white eye genes alone are enough to cause silvering, than all homozygous white eye birds should be silver dusted.

    It seems to me that there are two different things we are talking about (as @DylansMom has been asking):

    First, there is the question of the amount of white compared to the amount of "color" on the bird (i.e., what percent white is the bird?)

    Second, there is the question of the presence or absence of the "silver dusting," which may be a result of homogeneity for white eye (TWO white eye genes).

    The percentage of color is reportedly controlled by whether the bird is heterozygous for white & pied (believed to be alleles, resulting in a visibly pied bird), or homozygous for white (visibly a white bird), or homozygous for pied (visibly a dark pied bird).

    In order to get "silver pied," you supposedly need to add white eye gene(s) to get the loud pied (%50 percent white) up to 80-90% white. It sounds as though if you do that and the bird has one white eyed gene, it may not get the silver dusting, and perhaps the silver dusting shows up only when there are TWO of them (homozygous for white eye)

    Or then again, what if there's a "different" gene out there?

    @DylansMom has a bird which would appear to be 50% white or so -- which by consensus would typically indicate heterozygous for pied/white, and the bird is clearly, visibly "dusted," which would theoretically mean homozygous for white eye -- IF that is how it "works" to get the silver dusting. But theoretically, based on the explanations I've read, then the bird should have much less color on him, if indeed the addition of the white eye leucistic gene is also responsible for reducing the amount of color expressed on a loud pied (white gene/pied gene) bird.

    So far, the leucistic genes I've read about in peafowl consist of:

    white gene -- requires two to create a white (leucistic) bird
    pied gene -- an allele (or so it is thought) for the white gene which results in partial (or patchy) leucism
    white eye gene -- a leucistic gene which operates at a different place than the white/pied alleles, and which results in suppressing color (partial leucism) at a very specific location on the bird -- the center of the eyes in the train. It also apparently can express on some feathers in a hen. It is dominant -- so only one gene is required to express it -- but by most accounts, having TWO white eye genes results in a much stronger expression and is necessary in order to have a completely white eyed train. And possibly two white eye genes results in a silver dusted looking bird.

    Also unexplained is the possibility of "progressive" pied... a pied that increases the amount of white as the bird gets older, which is reported to happen to some birds. And reportedly, some white eye birds gain increasing numbers of leucistic ocelli as they age? So perhaps that would be a progressive gene as well -- or maybe a phenotypically pied bird with the progressive pied gene (if it exists) combined with white eye gene(s), most likely a single one (since two white eye genes would presumably result in a totally white eyed train from the outset?)

    Is it possible that DylansMom's bird is homozygous for pied (genetically a "dark" pied) as well as homozygous for white eyed? If the doubled white eye genes do act to further restrict the color on a pied bird, then instead of appearing mostly colored as a bird with two pied genes (rather than one white/one pied) would usually look, perhaps the addition of the doubled white eye could result in a bird which appears "loud pied" rather than "silver pied 80-90% white)" but with the silver dusting normally seen in the "silver pied with silver dusting" birds?

    The only other explanation I can think of is again, that maybe not all our white eye and/or pied and/or white genes are identical mutations, and there could be some variants floating around out there.

    Thoughts?
     
    Last edited: Nov 21, 2014
  2. connerhills

    connerhills Chillin' With My Peeps

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    Garden Peas.... If you will look on my web site and check under Bronze colors . There is a ( going on three this summer ) almost white and one in the same pen that is his brother all bronze. They came from a bronze male with no white at all on him and a female blue possibly split to bronze.. both of the males started out with a small amount of white flaking in the body one lost his and the other started to get a lot of pied effect and this year he has went almost white .. Now this is progressive pied and it is progressing to What ? I assume to a totally white bird.. All of the bronze are from a bird that was a bronze body and a white train with ONE Bronze feather in it. When it molted it came back in bronze , never to be white again . I have seen all white bronze with only a bronze head . Now this is not understood by most people and is not explained by all of the experts. I think if you did not know the start of something it is harder to put a finish to it ... George connerhills.com
     
  3. Garden Peas

    Garden Peas Chillin' With My Peeps

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    That is totally fascinating... really interesting, thanks! There have to be some more mutations that are out there we just haven't figured out.

    You know white horses start out dark, and gradually become whiter each year until they are all white... their coats lighten each time they go through a shedding cycle.

    Those bronze are gorgeous [​IMG]
     
  4. connerhills

    connerhills Chillin' With My Peeps

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    There are new mutations but no one has found them yet. A lot of people don't look for that little something that brings a gleam in your eye. George
     
  5. Garden Peas

    Garden Peas Chillin' With My Peeps

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    [​IMG]
     
  6. Dany12

    Dany12 Chillin' With My Peeps

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    Are there albino peacocks?
    Almost all animal species have albino mutations!
    Sometimes in wild Blue peacocks groups in India there is a white peacock .... albino or leucistic?
    If albino peacock existed it will appear in breeding farms!

    [​IMG]

    Strange color for a white wild peacock from Madurai India..... spotted !!!
    Genetically speaking .... a BOMB !
    But the Indians there don't care ... they are dancing!
    I go there for the next breeding season with two white peahen!
    Imagine Appaloosa peacock ... or Knabstrupper peacock !
    https://www.breyerhorses.com/files/...LEOPARD_APP_knabstrupper_heimdal_90811_LR.jpg
     
    Last edited: Nov 22, 2014
  7. Garden Peas

    Garden Peas Chillin' With My Peeps

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    Albino anything rarely survives in the wild. That is probably a leucistic (NOT albino) peafowl, as otherwise it would probably already have died.

    Leucism is not the same as albinism, the mechanisms biologically and genetically are different. The most obvious visual difference (and easiest for most of us to see) is eye color. Leucistic critters have normally tinted eyes (maybe faded looking), albinos have pink eyes due to the lack of melanin pigments.

    There is a BIG difference between leucism and albinism. These links explain it well:

    http://www.bto.org/volunteer-surveys/gbw/gardens-wildlife/garden-birds/behaviour/plumage/leucism

    http://en.wikipedia.org/wiki/Leucism

    http://birding.about.com/od/identifyingbirds/a/leucism.htm

    I'm still thinking about the two WE genes... it seems to result not just in white ocelli, but also in what the leucism articles call "dilution" -- a lightening or washing out of the color, which we see as dusting or silvering in our peas...
     
  8. DylansMom

    DylansMom RIP 1969-2017

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    Also if you play the video Dany12 posted, you can see what appear to be several colored feathers in various spots on the bird, I don't think a true albino would have any would it? I've seen pictures of Peas that were all white save 2 or 3 feathers and they were always called Silver Pied. I read some where that the presence of just 1 colored feather would make the bird a Silver Pied not a White. [​IMG]
     
  9. Garden Peas

    Garden Peas Chillin' With My Peeps

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    I guess I am trying to figure out why that one specific gene -- WE -- would act in two different ways on the bird.... #1 whiting out the ocelli -- a very specific location on very specific feathers, and #2 diluting the color or "silvering" feathers in other areas of the bird.

    Those are pretty different, pretty selective things... One of the reasons that I wonder occasionally whether there might be yet another gene involved that serves as a dilution gene. But so far, everything I have heard is that only birds with double WE genes show the dilution effect. I guess the test would be whether there are any silvered birds that do not have double WE genes?
     
  10. Garden Peas

    Garden Peas Chillin' With My Peeps

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    Yes, I believe you are exactly correct [​IMG]

    eta, and our white peas in captivity are leucistic white, NOT albinos, in case that wasn't 100% clear to anyone [​IMG]
     
    Last edited: Nov 22, 2014

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