splash x black sumatras all making black?

Discussion in 'General breed discussions & FAQ' started by Boggy Bottom Bantams, Jul 18, 2011.

  1. Boggy Bottom Bantams

    Boggy Bottom Bantams Overrun With Chickens

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    Alright, got one for all yall out there.
    A man e-mailed me the other day asking if I could help him figure something out.

    He has a pair of sumatras, rooster is splash came from blue to blue mating, hen is black from black to black mating.
    Threw the year he has bred and hatched from this pair 30 nice chicks. 29 are jet black and only 1 is blue.

    Problem is, as we know from splash to black all chicks are supposed to be blue.

    This was his question to me too , what was going on with them.

    Instantly, I thought, well he just has a blue and he's calling it splash. But no, he sent me pics of all the adult birds and chicks.
    In appearance the cock bird is a perfect splash in every way, and the chicks are just as black as they can be, the older ones are even getting the green shine to them already.
    Figured he may have just gotten some of those super dark near black looking blues, but after seeing the pics, that wasnt the case either.

    All I can figure at this point is genetically speaking, his splash really isnt a splash, but a blue, some how???

    Anyway, personally I have never had this happen. Just wondering if any of you may have an idea so I can relay it back to him as to what he has happening.

    OH, Yes the birds are penned together by themselves too, I asked that, he said they have been together since Jan or so with no other birds having access to the hen, plus the chicks are from half grown to a few weeks old, so it's been an on going process with his color ratios.
     
  2. tadkerson

    tadkerson Chillin' With My Peeps

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    This is what I love about chicken genetics- genetics that do not follow the norm.

    He needs to cross the splash with other blacks ( other breeds would be great) and see what happens.

    The young are inheriting a combination of genes that are preventing the blue allele from working.


    Hypothetically ( the simplest explanation), this could be a case of recessive epistasis with a penetrence level in the high 90 % area ( for blue). The high 90s would be normal for the blue color. Recessive epistasis would not be noticed unless you get an unusual circumstance ( with blue) where you know something is happening in the crossings. Usually crossings with blue produce splash, black and blue and people would not notice if there was recessive epistasis ( blue killer genes working) because they would assume the birds were a normal black.

    The failure of the recessive blue killer genes to be expressed would explain the one blue chick and the father being splash- the mother would have to carry two of the recessive genes ( blue killer) and could actually be blue. The blue chick and the father carries two recessive blue killer genes but the blue genes are still working.

    Father's genotype Bl/Bl and bk /bk and mother would be Bl/bl+, bk/bk or bl+/bl+, bk/bk.

    bk= blue killer gene

    The black chicks would have to carry two blue killer alleles one from each parent.


    It could also be another mechanism that is found in the promoter region of the blue gene.


    It would take some test crossing to determine the true nature of what is happening.

    This is a hypothesis and there is no data to support a blue killer gene- there is no such thing.

    Tim

    PS. Edited for clarification. I did not do a good job the first time.
     
    Last edited: Jul 20, 2011
  3. Sonoran Silkies

    Sonoran Silkies Flock Mistress

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    Love the theoretical explanation of a bk gene! Of course I am still figuring out the early part of your explanation on penetrance.
     
  4. Boggy Bottom Bantams

    Boggy Bottom Bantams Overrun With Chickens

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    haha me too Sonoran

    That's pretty much along the lines of what I told him I figured must be going on, just not in genetic terms. That something somewhere was either incorrect or stopping the blue genes from breeding threw in a "NORMAL" manor.

    So thanks Tim,
    I will copy and pass this along to him, he's not a member on here yet, so told him I'd ask
    I know the normal laws of genetics pretty well, but this abnormal stuff, well That's why I had to ask...just wasnt sure
     
  5. tadkerson

    tadkerson Chillin' With My Peeps

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    Quote:Genetics 101

    Genes are responsible for the production of some product by the cell ( this product causes a trait). If something interferes with the product, then the gene may not be expressed by the organism. Some genes are effected by the cells environment ( products due to other genes, sickness, lack of nutrition, etc.) or even the environment the organism lives within. If this happens then you get a number of organisms within the population that do not express the trait. If 3 out of 100 do not express a trait, then you have a 97 % penetrance in the population for the specific trait or gene. Normally extended black birds are black because of the E allele but occasionally a recessive white bird will pop up in a population.

    If a flock of black birds are allowed to freely mate, and 7 out of 100 birds from the flock were white, then the penetrance for extended black would be 93%.

    Expressivity is another term that is similar to penetrance. Expressivity deals with how the gene is expressed in each individual. The columbian gene is a good example because you can can get variation among birds that are genetically the same.


    Recessive white is an example of recessive epistasis. Epistasis is when one gene controls another gene. In this case the recessive white gene is controlling the extended black gene.





    Tim
     
  6. nicalandia

    nicalandia Overrun With Chickens

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    Quote:Genetics 101

    Genes are responsible for the production of some product by the cell ( this product causes a trait). If something interferes with the product, then the gene may not be expressed by the organism. Some genes are effected by the cells environment ( products due to other genes, sickness, lack of nutrition, etc.) or even the environment the organism lives within. If this happens then you get a number of organisms within the population that do not express the trait. If 3 out of 100 do not express a trait, then you have a 97 % penetrance in the population for the specific trait or gene. Normally extended black birds are black because of the E allele but occasionally a recessive white bird will pop up in a population.

    If a flock of black birds are allowed to freely mate, and 7 out of 100 birds from the flock were white, then the penetrance for extended black would be 93%.

    Expressivity is another term that is similar to penetrance. Expressivity deals with how the gene is expressed in each individual. The columbian gene is a good example because you can can get variation among birds that are genetically the same.


    Recessive white is an example of recessive epistasis. Epistasis is when one gene controls another gene. In this case the recessive white gene is controlling the extended black gene.





    Tim

    we sure miss you in the classroom at the coop...tim
     
  7. tadkerson

    tadkerson Chillin' With My Peeps

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    Thanks Nica,

    There are enough genetic types at The Coop.

    Tim
     
  8. nicalandia

    nicalandia Overrun With Chickens

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    Quote:true... but we have them here also... Henk has been a good teacher, wies, sonoran silkies, Mrs. KazJaps, all good people do you know where has Dr. Ron Okimoto gone? is he still working for the private sector?
     
  9. cubakid

    cubakid Chillin' With My Peeps

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    Is it possible the phenotipic "Splash" Cock might have been a genetic mutation in the birds, and it just looks splash and is actually something else( like Rec. White)?
    Zach
     
  10. Boggy Bottom Bantams

    Boggy Bottom Bantams Overrun With Chickens

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    Quote:That was the first thing I told my guy as well. I felt is was hiding it's true genetic ID. Visibly expressing splash but it's true genes were something of a different making.
    Relaid Tim's try a different breeding idea to him, will keep everyone posted on what hatches next.
     

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