• Question: How exactly is the cloning of an organism achieved?

    Asked by rhooper821 to Ben, Dave, Ed, Sam, Susana on 19 Jun 2013.
    • Photo: David Briggs

      David Briggs answered on 19 Jun 2013:

      Well, the easiest way it probably to take a fertilised embryo, take the nucleuses (the bits with all the DNA) of the cells out with a micromanipulator and then insert nucleuses from what ever it is you want to clone, then re-implant the embryo in a surrogate mother.

      That might work.

    • Photo: Benjamin Hall

      Benjamin Hall answered on 20 Jun 2013:

      Dave has answered for animals so I’ll give you plant cloning for absolute beginners:

      1. Find yourself a plant. One that you want to clone.

      2. Acquire some cells from this plant. From anywhere. Plants are so cool because, unlike animals, most plant cells are what we call totipotent. That means they can differentiate, from a single cell, to the extent where a whole new plant can be formed given the right conditions. So you could simply get a few root cells and culture these to form what’s known as callus (a mass of undifferentiated cells) or you could take a whole leaf and induce that to form roots and shoots.

      3. Once you have your cells, you might want to just make an exact copy of the plant you started with. Or… you might want to add something. At this point you can use agrobacterium to transfer genes to the plant tissue to create a stable genetically modified plant.

      4. Grow the cells with specific nutrients. Two plant hormones are important here; auxin and cytokinins. Auxin encourages roots to grow and cytokinins encourage shoots to grow. People typically grow the cells in a media which has a good balance between the two hormones which causes callus to grow, then slice off the shoots before transfering them to an auxin rich medium to encourage root growth.

      5. Once these little plants are big enough, you can transfer them to regular soil and they’ll end up more or less the same as their parent, allowing for environmental factors.

    • Photo: Sam Horrell

      Sam Horrell answered on 21 Jun 2013:

      Dave and Ben got animals and plants so I’ll give you the bacterial version. This is also very relavent to our work producing proteins.

      First thing to do is take a little circle of DNA called a plasmid. These contain antibiotic resitance genes so we can select for certain bacteria and other sequences that we can use to turn on protein production.

      You then cut the circle with an enzyme so you can add a gene you’re interested in and stick the circle back together. This gene is normally a protein we’re interested in producing.

      The next step is tranforming the bacteria, this involved taking your plasmid and putting it into the bacteria. All you really need to do is add the 2 together in a test tube, warm them up for 2 minutes and leave them for an hour.

      Once that’s all done we grow our bacteria on agar (a kind of seaweed jelly) in a perti dish. There are antibiotics in the agar that kill all the bacteria apart from the bacteria with our plasmid, because of the antibiotic resistance genes we added.

      And that is molecular cloning. A simple days work.

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