Can anyone explain the term "sex-link"?

Discussion in 'Ducks' started by QuackerJackFarms, Jul 22, 2011.

  1. QuackerJackFarms

    QuackerJackFarms Chillin' With My Peeps

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    I keep seeing people use this term, and instead of googling, I'm just asking here. The main reason I want to know is pertaining to my supposed Rhode Island Reds that I got from TSC. But..... they don't look like RIR's and the supposed Rouens I got there ended up being Mallards.

    I saw a post that says TSC sells "sex-links" so now I'm curious.
     
  2. Senna95

    Senna95 Chillin' With My Peeps

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    Actually, that is a good question, since it used in different ways, but all relating to the same basic thing:

    Sex-linked gene: a gene (or piece of genetic information) that is contained on a part of the sex-chromosome that determines the sex of the offspring. Males have 2 long matching chromosomes, and females have one long, and one short. Offspring inherrit one from each parent. Each get a long chromosome from the father, and either a short or a long from the mother: if they inherrit a long one from mom, the baby will be a boy (2 long chromosomes), and if they get a short one it will be a girl (one long from dad, and one short from mom). Any genes contained on the part of the long chromosome (in both males and females) that is missing on the female shorter chromosome is a sex-linked gene. Female offspring would only be able to inherrit these genes from the father, since the mother didn't donate any due to the chromosome being shorter.

    How does that relate to color breeding?

    Well, Brown dilution for example: let's take a chocolate male and a black female. Brown dilution is carried on the sex-chromosome. So dad (the chocolate male) would carry 2 recessive brown dilution genes. The female wouldn't carry any, because she only has one loci for this gene because she is "missing" the second long-part of the chromosome, so she would only need one recessive brown dilution gene for it to show (it would have no competition for dominance). And she is black, so she has no brown dilution. So you mate these 2 ducks, and all babies inherrit one brown dilution gene from dad, but none from mom. All males babies will have one brown dilution gene, but also one dominant non-brown gene. All males would be phenotypically black. The females however, would all inherrit one brown dilution gene, but no other gene to compete with it. So all females would be brown.

    With chickens the barred pattern is sex linked. That's why you can cross a red rooster with a barred hen. All male offspring will be barred, and females are black/brown.

    This comes in handy when you want to know the sex of the babies so you can choose and raise them accordingly.
     
  3. duck15

    duck15 Chillin' With My Peeps

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    ^ i dont get it to
    can you explain more?
     
  4. birdboy508

    birdboy508 Chillin' With My Peeps

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    sex-link i think it means they bread well.
     
  5. groundpecker

    groundpecker Chillin' With My Peeps

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    My inferior example of a type of sex link

    One example of a Red sex link: When you take a White leghorn male and breed it with a rhode island red female.

    Red sex link hen [​IMG]

    The purpose of this kind of breeding is to be able to select the males from females upon hatch, from what i understand.

    Look more closely in the forum. I believe this has been explained in more depth in the breeding thread, there are others with more experience than me about sex linking.
     
  6. Egghead_Jr

    Egghead_Jr Overrun With Chickens

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    Quote:Uh, no. Sex, as in male or female, is linked by color. Red sex link females will be red with white leaking, males all white. Black sex link females will be black with some red leaking, males will be barred. Amber sex links, comets etc. etc. are variations of these two most common cross breeds which are sexable by color the first generation, there after are mutts and randomly colored. There are a few pure sex links, in that they are a pure breed and sexable at birth. The legbar and ... I forget, not many of them.
     
  7. Senna95

    Senna95 Chillin' With My Peeps

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  8. roocrazy

    roocrazy Chillin' With My Peeps

    Jun 11, 2009
    minnesota!!!!
    Quote:no. you cant use leghorns as they do not carry the silver gene. and the rooster must be red(gold, buff) and the hen must be silver(colombian, light, silverlaced, RIW) it cannot be revesed. the rooster passes the gold gene to his daughters making them red/gold, the hen passes the silver gene to her sons, making them silver, with some red leakage occasionally.
     
  9. QuackerJackFarms

    QuackerJackFarms Chillin' With My Peeps

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    Wow. Thanks for the posts. I have alot to learn here but that is a great start.
     
  10. 70%cocoa

    70%cocoa Chillin' With My Peeps

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    I think that Senna95's explanation is really good. Come back to it when you've read Rollyard's description (also excellent).

    Basically, to get parents to produce males in one colour and females in another colour (sex linking) you need a male with two recessive genes that are carried on the Z (long) chromasome and a female with a dominant gene, also carried on the Z chromasome (she will have only one of these as she only has one Z chromosome). That is the general principle. In ducks, you'd want a chocolate male and a black female (as per Senna's example). The female offspring will look like the father and the male offspring will look like the mother.
     

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