Where is the person's "unique id" in the genome?

Discussion in 'Health and medical' started by Ramon F Herrera, Jan 27, 2004.

  1. I was watching the excellent documental "DNA" in PBS, and they mentioned that there is a section in
    some chromosome which is unique for every individual. This is the section used in identifying
    criminals, etc.

    Where exactly is this section located? Where can I read more about it?

    TIA,

    -Ramon
     
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  2. Guy Hoelzer

    Guy Hoelzer Guest

    in article [email protected], Ramon F Herrera at
    [email protected] wrote on 1/27/04 10:58 AM:

    > I was watching the excellent documental "DNA" in PBS, and they mentioned that there is a section
    > in some chromosome which is unique for every individual. This is the section used in identifying
    > criminals, etc.
    >
    > Where exactly is this section located? Where can I read more about it?

    I think you misunderstood. There is no particular section of DNA designed to mark individual
    identities. There are, however, many (hundreds of thousands) of places in the genome that exhibit
    much higher mutation rates and current variation than other regions of the genome, and a small set
    of these regions (dozens of them) is commonly used to identify criminals, etc.. These hypervariable
    regions are called by many names, the most common of which is "microsatellites," which are
    characterized by a series of short (about 2-8 bases) tandemly repeated sequences. You find
    microsatellites everywhere you look in the genome.

    Guy
     
  3. J Moore

    J Moore Guest

    I was looking for a decent link to get some basics for you, but it turns out
    to be difficult because of having to wade through a lot of ads for DNA ID
    kits. I did find this one which is informative and straightforward.
    http://www.kgl900.com/html/body_dna.htm

    The upshot is that they don't check one area, and that to be absolutely accurate you'd want to check
    the whole genome, which is of course not practical now. So they check a number of areas where you
    usually see the most differences between individuals. Finding that just one of these matches doesn't
    necessarily make for a correct ID, but as you find more areas matching the odds go up that you're
    seeing a correct match. This is a bit like saying we've got a guy named Herrera, so is that you?
    Maybe, but there's a lot of people with that name. So they look for a first name, and an initial,
    and an address, and maybe an age, and height. Now if all those match, it's probably you. The odds
    are that there isn't somone else at that address with the same name, age, height, etc., and the odds
    get better the more things you check and find matches for. So that's what they're doing with DNA
    identification.

    Jim

    Ramon F Herrera <[email protected]> wrote in message news:[email protected]...
    > I was watching the excellent documental "DNA" in PBS, and they mentioned that there is a section
    > in some chromosome which is unique for every individual. This is the section used in identifying
    > criminals, etc.
    >
    > Where exactly is this section located? Where can I read more about it?
    >
    > TIA,
    >
    > -Ramon
     
  4. [email protected] (Ramon F Herrera) writes:

    > I was watching the excellent documental "DNA" in PBS, and they mentioned that there is a section
    > in some chromosome which is unique for every individual. This is the section used in identifying
    > criminals, etc.
    >
    > Where exactly is this section located? Where can I read more about it?

    The forensic use of DNA is discussed at some length in Richard Dawkins's _Unweaving the Rainbow_,
    chapter 5, "Barcodes at the bar".

    If I remember correctly, the most common thing to do is to check the number of tandem repeats in a
    particular piece of non-coding / junk DNA. Tandem repeat sequences in non-coding DNA typically (?)
    varies a lot in a population, it will likely differ on the maternal versus the paternal chromosome,
    and is easy to measure.

    Morten
    --
    Ees a sad an' beautiful world
     
  5. [email protected] (Ramon F Herrera) wrote in message news:<[email protected]>...
    > I was watching the excellent documental "DNA" in PBS, and they mentioned that there is a section
    > in some chromosome which is unique for every individual. This is the section used in identifying
    > criminals, etc.
    >
    > Where exactly is this section located? Where can I read more about it?
    >
    > TIA,
    >
    > -Ramon

    Are you referring to the Mitochondra DNA?
     
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