• Question: Chemical modifications to the DNA can make a gene more or less active is this right?

    Asked by Ayse to Tristan, Sophie, Ravinder, Matt, Barbara on 7 Mar 2015.
    • Photo: Barbara Shih

      Barbara Shih answered on 7 Mar 2015:

      :p Did you ask the same question three times?

      Man, you guys learn about this so early. I only learnt about epigenetics at the university! Anyway, I think this video explained it well. https://m.youtube.com/watch?v=kp1bZEUgqVI

    • Photo: Matthew Moore

      Matthew Moore answered on 10 Mar 2015:

      That’s true!

      In all your cells there is the same DNA, yet a liver cell and a skin cell or a white blood cell look really quite different. Epigenetics is the term given to chemical modifications to DNA or to histones which hold chromosomes together.

      Chemical modifications of either the DNA (usually methylation) or of the histones which hold the DNA together in a compact form allow different genes to be turned on or off with quite different results!

    • Photo: Sophie Robinson

      Sophie Robinson answered on 10 Mar 2015:

      This is very true. All our cells have exactly the same genes and DNA inside them, however a muscle cell and a white blood cell are very different. The reason they can be different and have the same DNA is because different genes are turned on and off in each of the cells by chemical modifications. This process is called epigenetics.

      When this process goes wrong it can have severe consequences. For instance a disease called FOP causes sufferers to be slowly imprisoned in their own skeletons. This happens when the gene for bone growth stays switched on in muscle cells when it would normally be turned off by epigenetic modifications. This results in patients’ muscle tissue slowly turning to bone. A very nasty disease indeed.

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