Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: thedoc on 05/08/2012 21:30:01
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Luke Bizeray asked the Naked Scientists:
Is there a way to make sure the genetic differences in GM crops are recessive genes? That way if they got out into the wild, the genetic changes wouldn't carry through.
Luke
What do you think?
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Hi,
making genes recessive will only prevent them to not show up in the first generation after crossing a GM plant with a natural one. However, the genes are still there and will show up in the next generation. If they are advantagous, they can of course spread much more. If not they will disappear. So making genes recessive will not help.
To the first part of your question: A typical recessive gene is the absense of a protein (or the presense of a defective form of a protein). However, this is not why a genetic manipulated plant is made. You do the genetic manipulation to produce additional proteines. This means typically also you add new genes (and do not replace natural ones by others). So typically (and systematically) they are not recessive. A generic mechanism to make a single new gene only work in the case that it is present on both (or in the case of plants on all equivalent) chromosomes is hard to imagine and harder to design.
What you can think of is, if two genes (or multiple) or needed for one desired feature, that one gene is on one chromosome and the other on the other analaogous chromosome. This way all the immediate offspring will not have the feature and only in the next generation (if two different "bastards" are the parents) the feature can appear again. However, over time a crossing over, can bring them on a single chromosome. But that again requires that this is an advantagous feature also in wild life (otherwise it will quickly disappear anyhow).