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16 August 2006

Top 5 coolest things to do with genetic engineering

Biotechnology is my passion. After being inspired by Arcadia's Week Of The List, I would like to share 5 really cool things that 21st century biotechnology can do.

1. Ripe and ready to eat. CalGene's Flavr Savr tomato will always have a special place in history. It was the first ever GM food to be approved by the FDA way back in 1994. Normal tomatoes are picked green and hard and then left to ripen in the grocer's cooler. Flavr Savr tomatoes promised juicy vine-ripeness without spoiling during the picking, transportation and storage steps. This exceptional shelf-life worked by silencing the gene responsible for producing ethylene. This gas is produced by ripening fruit, especially bananas and avocados, and keeps the ripening process going. Without the ability to make ethylene, Flavr Savr tomatoes ripen on the vine to a pink blush and then stay in that state until they can be treated with exogenous ethylene right before putting them on display in the store. These GM beauties were last seen on shelves in 1997. Why were they pulled from the market? Not because of any fears about frankenfood, but because they were still picked and transported using traditional hard green tomato methods and equipment. Damage to the soft and squishy Flavr Savr tomatoes was as much as 30% by the time a desperate housewife could lay her hands on one. It was just not economically viable to keep the Flavr Savr going.


2. Got silk? Spider silk has a myriad of potential uses. For a start, it's a really strong protein: stronger than kevlar or reinforced steel, we're told. It's of obvious interest to structural engineers and fashionistas who like their ball gowns bullet proof. But spider silk is a precious commodity and spiders do not cope well with being farmed. Nexia Biotechnology in Quebec Canada has produced transgenic goats that secrete spider silk in their milk. That's right. Just skim it off, stretch, leave to dry, spin into fibres. A visionary technique for mass-producing the fibre of the future.

3. Red alert. The Danish company
Aresa has genetically modified the thale cress (Arabidopsis thaliana), a humble weed, to turn a bright red colour when it encounters unexploded land mines underground. This would help alleviate the suffering of people in countries riddled with dormant mines. The explosives slowly release nitrogen dioxide which then causes the leaves of the plant to turn their autumn colours. The genes responsible for producing the red pigment anthocyanin are usually switched off for most of the year, but these scientists have inserted an extra gene that turns on this whole biochemical pathway in the presence of nitrogen dioxide. In true Jurassic Park style, the company has made their patented BioSensor plants dependent on a specific fertilizer mix, so they won't escape into the wild.

4. Something fishy. Certain fish that live in Arctic and Antarctic waters secrete special proteins that protect them from freezing. If such a fish swallows a small ice crystal, these antifreeze glycoproteins bind to it and prevent it from growing larger. Scientists have already produced varieties of potatoes and tomatoes expressing these genes, with the potential to thrive where the dangers of frost would kill lesser crops. But would your salad still be vegetarian?

5. Hot stuff. This is an idea I had in my Honours year for a biotech experiment. Since tomatoes and chillies are in the same plant family, the Solanaceae, they share several characteristics. One feature exclusive to chillies is their burn. This is caused by the capsaicinoid molecules produced by the placenta (the membrane that connects the seeds to the fruit wall). Incidentally, capsaicinoids are produced by chillies to prevent mammals from eating the fruit. The mammalian digestive system destroys chilli seeds, whereas those of birds leave them intact to germinate. Birds do not have the pain receptors sensitive to capsaicinoids and therefore experience no heat rush when feasting on a habanero bush. How cool would it be to transform tomatoes with the genes for the enzymes in the capsaicinoid pathway? It should be a breeze, as the two crops are related. You then get hot tomatoes, useful in relishes and hot salsa. Land used for the production of tomatoes and chillies will be used for growing hot tomatoes with twice the yield. Simple? Not really. The enzymes that produce capsaicinoids haven't all been discovered yet. But if you give me some money, I'll gladly do it for you...

17 comments:

  1. dude, ek check elke dag hierdie blog en het vandag eers die lys gesien...weird. dankie vir die saamspeel, though!

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  2. Coolness. Enjoyed that one.

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  3. What's with the lists! Everyone has got list fever. I did enjoy yours though. I remember your chilli-tomatoe days. I always thought your idea was genius.

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  4. what a brilliant list - really enjoyed reading it

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  5. I loved this list - there was so much weird and wonderful stuff in it that I'd never heard of bfore. I told my whole family about it.

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  6. great list!

    chilli tomatoes! thats pretty kewl.

    is there some way to then make chilli's that arent hot? for all the senior citizens who insist on eating things (like spicy food) when their systems cant handle it anymore...

    seems the possibilities are endless.

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  7. It should be really easy to make mild chillies - it'll be the same kind of gene silencing as in the Flavr Savr tomato. Basically, you would knock out one of the enzymes in the phenylpropanoid pathway, preventing capsaicinoids from being made. Voila!

    However, chilli plants are notorious outcrossers, so the next generation sown from seed would probably have their burn reinstated. Yup, the grannies would have to buy their seeds directly from me, their friendly faceless corporation. *Evil scientist laughter*

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  8. Re the flower which detects landmines. If it can't grow out in the wild, then how are they going to find dormant land mines? I mean, are you going to have to plant fields of the flower in order to find mines? I don't envy the guys digging holes in a landmine field to plant these flowers...

    Or am I getting it completely wrong, and you're saying that you just need to carry a leaf of it around with you? :)

    Either way - interesting list! Amazing what science can do for us these days.

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  9. The usual method of sowing really fine seed is to mix it with sand, a binder, or a fertilizer. Therefore, the BioSensor Arabidopsis plants could be delivered via low-flying aircraft, together sufficient nutrients to see them through their job, but not the first winter. Sorted.

    NOTE: these plants have not as yet been employed in actual mine fields. But the field trials look promising.

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  10. i love your blog!!!! its like a well of interesting facts :)

    (just a little note of appreciation)

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  11. Here's what Karen and I want to know.

    What is it that makes us choose a particular flower to love?

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  12. cool list......it's covered my learning something new for the next little bit

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  13. Facehugger?
    Is that what you guys in Africa call goats?

    Hee hee!

    Thank you passing by. Been a busy-ass summer, huh?!

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  14. Did you read the book on the Calgene work? It was a pretty good insight on how science isn't the only part of the problem - they totally failed to see how tomatoes are marketed and shipped (also how many damn varieties there were to deal with). It's a better book than Lords of the Harvest imo.

    Cool list.

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  15. You read First Fruit?! I am impressed. It's gone out of print now, and nobody seems to have ever heard of it. But, yeah, you're right - a cool idea is no good if you haven't done the market research.

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  16. First Fruit - yes, I'd just spaced on the title. I was particularly impressed by the marketing input that wanted them to get the tomatoes to grow faster.

    So what's your take on genes being crossed out into natural species?

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