- A technique for producing "environmentally friendly"
GM crops has been called into question by a study showing how easily alien
genes can be transferred around a plant.
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- Scientists have found that genes can jump from one region
of a plant cell to another, making more likely the prospect of an introduced
gene contaminating the plant's pollen and escaping into the wild.
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- The research, led by Jeremy Timmis of Adelaide University
in Australia, focused on the DNA of chloroplasts ñ the photosynthetic
structures inside a plant cell ñ which lie outside a plant's nucleus.
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- Some researchers have suggested that by modifying the
DNA of chloroplasts, GM crops might be created with beneficial traits that
cannot be transferred to the plant's pollen and be released into the wild.
Pollen is made using DNA from the cell's nucleus.
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- But Dr Timmis has shown in a study published in the journal
Nature that genes introduced into the DNA of a chloroplast can indeed jump
into the chromosome of the cell's nucleus. By modifying the genes of chloroplasts,
therefore, the theoretical possibility exists to generate GM pollen that
could cross-fertilise with related species of plants, producing GM wild
flowers or "superweeds" resistant to weedkiller.
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- Dr Timmis's team used a gene that confers resistance
to an antibiotic as a "marker", to see how frequently this alien
DNA could move from the chloroplast to the nucleus of a tobacco plant.
They found DNA is transferred at a frequency of one in approximately 16,000
tobacco pollen grains.
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- Peter Riley, of Friends of the Earth, said: "This
research suggests that this is a bit of a shock to scientists. They didn't
expect the genes to jump from chloroplast to nucleus so readily. It underlines
the fact that we must know more about plant genetics before we start manipulating
the DNA of crops."
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- http://news.independent.co.uk/world/science_medical/story.jsp?story=375935
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