• Question: Is the microsatellite you describe different from an intron or is it the same thing? I'm currently doing an Open University course in genetics and I'm wondering if i've just completely the wrong idea?!

    Asked by nadiaeg to Anouk on 20 Jun 2012.
    • Photo: Anouk Gouvras

      Anouk Gouvras answered on 20 Jun 2012:

      Hi nadieg,
      no they are not the same thing but I do see the logic.

      So, an intron is a part of DNA that does not get coded into mRNA, it is referred to as ‘junk DNA’, whereas exons do get coded into mRNA. An intron = non coding DNA, and exon = coding DNA.

      Microsatellites which are also called simple sequence repeats (SSR) or short tandem repeats (STR), are segments of DNA composed of small repeated units between 1-6 base pairs long. They can be found anywhere on the genome, in coding and non coding regions, so they can be found on exons and introns, although they are more common on introns.

      Here is a paper that might be helpful to you http://www.ncbi.nlm.nih.gov/pmc/articles/PMC310925/

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