The GM Crop Forum
Threads - Fw: Media Release on GM
Crops Forum Convened By AIAST
On
14/6/2002, Podargus posted:
Media release
Issued June 19, 2003
Ag Science Institute tackles GM deadlock
New South Wales has out-capitulated Victoria on the genetic
engineering front, imposing a three-year moratorium on the release
of genetically modified (GM) food crops last week.
But what happens when GM-crops are eventually released? What will be
the consequences on the environment, farm productivity, trade and
human health? A moratorium does not answer these fundamental
questions.
According to the Australian Institute for Agricultural Science &
Technology (AIAST), the industry has reached a critical milestone
and must now face some tough decisions about the future of crop
production in this country.
"As an industry and as a profession, we now face a real moment of
truth,” said Turlough Guerin, president of the NSW branch of AIAST and
convenor of a forum to be held in Sydney next month to debate the GM
issue. Dr Guerin hopes the debate will help lead the industry out of the
current deadlock. "Focused debate is urgently needed to communicate the
genuine risks and rewards of this technology," he said. "We are the
leading body of professionals in agriculture and natural resource
management and are well placed to sponsor this debate in an open and
objective way.”This process will also help identify where R&D funds
are needed to fill the gaps in our knowledge of the risks," he said.
Dr Guerin said the GM-crop issue lay at the heart of agricultural
sustainability because the potential flow-on effects would reach into
many industries and communities, ultimately impacting on markets and
export revenues. He said the forum would be titled "Release of
Genetically Engineered Crops in NSW - What are the Human Health,
Environmental, Commercial and Trade Issues?"
One of six speakers to be invited is Lindsay Cook, chief of NSW
Agriculture’s Division of Plant Industries. Dr Cook will present the
import of the recently passed NSW legislation titled Gene Technology (GM
Crop Moratorium) Bill 2003.
TJ Higgins, assistant chief of CSIRO Plant Industry, will provide
insights into the science behind the GM-crop debate. "Selective breeding
by humans over thousands of years has led to improved forages and
crops and has given us most of the commercial crop varieties
we use today," said Dr Higgins. "Traditional breeding, however,
runs into some insurmountable hurdles and certain advances in plant
improvement can only be made through gene technology.”Already,
genetically modified plants have significantly reduced pesticide use in
Australia," he said.
However, Dr Higgins also issued a caution: "As with all new
technologies, there may be risks associated with gene technology. But
testing, identifying and addressing the potential risks is helping to
build confidence that the benefits of these technologies will outweigh
any risk," he said.
A former head of Sydney University's plant breeding program, Don
Marshall of Plant Breeding Solutions, also stresses the need
for the assessment of risks from the flow of genes from
genetically modified crops to the wider environment.
"Contamination of non GM-crops and plants from gene flow through pollen
or seed is often cited as a major environmental risk posed by GM-crops,"
said Dr Marshall. "However, the potential risk of such contamination
varies markedly between crops from virtually zero to 100%.”The factors
that affect the probability of contamination include the size of the
crop, its mating system, the nature of the commercial product and the
propensity of the species to survive in feral populations."
Dr Marshall said there were issues to consider from the conventional
crop grower’s perspective as well. "On the receptor side, some of the
major factors affecting the risk of contamination include the size,
distribution and proximity of non GM-crops, volunteer populations or
related weeds and wild relatives.” The potential for hybrid
formation between the GM-crop and the recipient population - and their
likelihood of survival in the cropping system - must also be assessed,"
he said.
Bruce Finney, central regional manager for Twynam Agricultural Group,
will provide a grower's perspective. Twynam is one of Australia's
largest producers of GM-crops and the group recognise that biotechnology
is a valuable tool for improving the sustainability of farming. Mr
Finney said the introduction of GM-cotton in Australia had been a real
success story, bringing significant reductions in pesticide use. But the
group also believe that genetically engineered traits need to be
assessed on their individual merits, inferring that some GM-crops may
not be acceptable. "Australia has a highly regarded regulatory system
that assesses the risks of each proposed GM-crop to human health and the
environment," he said. "By contrast, the ongoing debate on the release
of GM canola has highlighted that we are yet to develop an equally
effective process to manage the commercial risks.”Grower views need to
be sought and their interests protected. Freedom to operate GM,
conventional and organic production systems in co-existence must not be
compromised by cost burdens and failures in risk assessment," he said.
Vice-president of the National Farmers Federation, Wayne Cornish, who
is calling for balanced debate on the issue of growing GM-crops, will
also speak. Mr Cornish has acknowledged there are potential benefits for
Australian farmers through the integration of biotechnology within
production systems. He believes GM-crops have the potential to reduce
pesticide and herbicide use, increase water use efficiency, tolerate
adverse growing conditions and improve yields. "While the adoption of
GM-crops may result in more efficient production, it is important that
producers understand and assess potential risks and implement strategies
to manage these," he said. "It is also important that agricultural
supply chains allow for all producers to continue meeting the
requirements of their chosen markets.” Farmers must be afforded
choice in the method of production that best meets their needs and
allows them to meet market expectations," he said.
The forum will be held 2-6 pm on Monday July 14, 2003, at the Duxton
Hotel, 88 Alfred Street, Milsons Point, NSW. At $70 per head,
refreshments will be provided and delegates are invited to stay for
drinks from 6:30 pm. To register contact Roger Fitzsimmons at
aiastensw@optusnet.com.au.
Ray
responded:
I'd
like it noted, that my objection to any lack of caution in releasing
herpes contraceptive has nothing to do with its genetically engineered
source.
It's
the viral nature of the problem, and our apparent history and current
ignorance in knowledge of how to contain them.
Mass
production of human proteins, and other biochemicals, by genetically
engineered bacteria, we can live with as long as we can kill the bug,
but virus gave us smallpox and HIV and SARS.
If
no other argument, we're just not ready to take that kind of risk.
Rod Olsen
replied:
Please do not
jump up & down on this old bloke but - how is "engineering viruses"
different from "engineering crops"?
As I understand
it, the concern over GM Canola is that its seed would spread on the wind
to farms that choose not to grow GM canola but the traditional
variety. IF this is a legitimate concern:
- how do you stop the wind blowing the GM seed into areas where it
is not wanted by traditional farmers?
- given that genetic drift and other randomness comes into play,
how certain are the GM proponents that there are no potential problems
(yield, pest/disease susceptibility, etc) arising from GM &
traditional crops mixing in the wild?
- I can appreciate the GM benefits from modified cotton but it is
not a food crop - the risk to food crop productivity from unintended GM
consequences is not an issue, however I have considerable concern about
cotton's huge demand for water and for artificial fertilisers in an
environment as fragile as the arid Darling river basin.
Please
understand that we civilians have had some nasty experiences with
unintended consequences with agricultural & related sciences
(pesticide residues and their impact on humans, food animals, river
systems, native fauna & flora). Us oldies are not expert in
all the science/technology involved, we just have some concerns which
seem legitimate to us.
At the risk of
being flamed, would you accept GM humans eg introducing genetic
material into developing human embryos to introduce "natural immunity"
to diseases affecting humans, such as GM sickle cell anaemia to provide
immunity against malaria as readily as you
appear to accept GM food crops?
In case I have
upset/annoyed some supporters of GM technology/science on this Forum,
please remember that the old bloke you flame is somebody's granddad.
Ray
answered:
Rod,
plants can be controlled with fire, with weedkiller, with machette and
flood (if you're so lucky). Also you can see macro plants, you
can't see virus without assistance.
No
equivalent controls exists for too many virus.
The
only treatment for virus like the common cold and herpes, is relief for
the symptoms.
That
is the difference.
Peter Macinnis
responded:
>
Please do not jump up & down on this old bloke but - how is
"engineering
> viruses" different from "engineering crops"?
Possibly because
qualified scientists could be concerned about risks from the virus, but
few without an axe to grind would carry on about GM canola. A
scientific case could be made for the virus doing harm -- I am not
saying it would be a feasible case, but one could be made, and it needs
to be shown to be improbable. There IS a middle ground, and that is
where we will end up.
>
As I understand it, the concern over GM Canola is that its seed would
spread
> on the wind to farms that choose not to grow GM canola but the
traditional
> variety. IF this is a legitimate concern:
No, it is more
the spread of pollen than the spread of seed, though this is all a bit
of a red herring. The gene for Roundup resistance does not, in and
of itself, make the GM canola nasty, and I am *fairly
sure* the
gene is not found in canola oil. The usual bleat is about "genes
in our food", as though there aren't genes in everying we eat.
The next effort
is to call it "unnatural", when horizontal gene transfer happens all the
time.
My beef with the
loopy left is that they carry on like a regimented array of pork chops
without knowing what they are talking about, and so deaden Joe Public to
the issues that should cause concern. They should spend more time
studying, so they are able to point to REAL risks.
We have a
budding biotechnologist in our house, and we were discussing methods
over dinner last night -- he referred to the use of 'grass organisms' -
'grass' being GRAS, generally regarded as safe. If you are
modifying a lactobacillus to make better yoghurt, you cannot source
genes from E. coli, you cannot even use an E. coli promoter -- the whole
industry is based on being doubly safe. This was news to me, and I'll
bet it would be news to most of the protesters.
>
- given that genetic drift and other randomness comes into play, how
certain
> are the GM proponents that there are no potential problems (yield,
> pest/disease susceptibility, etc) arising from GM &
traditional crops mixing
> in the wild?
"Genetic drift"
has a specific meaning, relating to random changes in gene
frequencies. I can't see how it is relevant here: can you amplify
this a bit?
>
I can appreciate the GM benefits from modified cotton but it is not a
food
> crop - the risk to food crop productivity from unintended GM
consequences is
> not an issue
Google "golden
rice", which the loopies hate, because it only has benefits, is not
owned by Big Agribusiness, and it saves lives. they accuse the
scientists of "cheating" by doing good, and say it is only done with
malicious intent, in order to get GM accepted. They would rather see
people starve (here, sadly, I have to agree with Dubya, though I doubt
that we share many motives).
With no
self-promotion intended, may I refer you to http://www.abc.net.au/rn/science/ockham/stories/s289416.htm where I
explore the way
technologies advance? GM is too new, and we have no way at all of
knowing what the benefits of a new industry may be, and even less of
guessing what the disadvantages will be. (With full self-promotion
intended, I will bury here the note that a book called "Rockets: Sulfur
Sputnik and Scramjets" is to be let loose on the world on July 11, and
it also uses this question of how technologies mature and produce
unexpected effects.)
>
At the risk of being flamed, would you accept GM humans eg
>
> - introducing genetic material into developing human embryos to
introduce
> "natural immunity" to diseases affecting humans, such as GM sickle
cell
> anaemia to provide immunity against malaria
This is gene
therapy, and yes, I would be inclined to do accept it in the long term
-- but not just yet, as there have been a number of cases of unusual
cancer associated with attempts to treat children with SCID (severe
combined immunodeficiency disease) -- Google those names or Alain
Fischer at the Necker Hospital. In this case, it may have been the
carrier that was used -- last I saw, nobody was certain, but there were
definite suspicions.
Be aware that
SCID is not necessarily a fatal condition IF a perfect-match bone marrow
transplant can be arranged, but finding a suitable donor may not be
easy, and as many as 30% or 40% of victims die of the disease. On that
basis, it was deemed appropriate to try, but once the cancer cases
started to show, the trials around the world were stopped.
The whole matter
is a slippery slope -- do we then modify a tennis player's genes to give
him/her longer arms? My long bones are two standard deviations
shorter than they ought to be for my body size -- it is not dwarfism,
but causes a few MINOR annoyances -- like having trouble reaching my
toes. Should I get the arm and leg lengthening, but not the tennis
player? Or should we modify trees to produce more cellulose and less
lignin to generate 'greener' paper? Maybe we would be better
concentrating on finding alternatives to paper?
>
In case I have upset/annoyed some supporters of GM technology/science on
> this Forum, please remember that the old bloke you flame is
somebody's
> granddad.
Speaking as one
of the more rabid pro-GM advocates, the questions you raise should not
provoke flaming, nor should an expressed opinion based on an ethical
stance. In the end, people started shouting at Wolfie because he kept
raising the same issues, even when they had been answered, a bit like
the creationists. If you raised the "tomato with fish genes"
story, and were told that it never existed, and you kept asserting that
it did, with no evidence, then people might get a bit frosty, rather
than flaming you.
As I implied in
the tennis-player example, at some point, we will need to draw a line in
the sand, and that will come down to values and ethics. Flaming is
inapposite, but some of the disputation is bound to get a little
heated, since logic and facts will not be relevant data.
Hopefully, by
then the facts will be agreed and understood. That agreement and
understanding will not come from brutally beating down the questioners.
Toby Fiander responded:
>
I am *fairly sure* the gene is not found in canola oil.
The
process is intended to collect oil, which has no genes. However,
no process is perfect and there is a minute amount of material
that might be referred to as DNA in most edible oil. It is even
likely that the cheaper and nastier the product the less perfect
the extraction process, but the amounts are probably still tiny.
There
are issues about GM canola and multiple pesticide resistance, but they
are probably relatively minor and not as represented
in the article in the British papers this week, which has the same
misunderstandings that they had 12 months ago. Wolfie's
characteristic, to ignore sound data-based argument because it did not
fit his worldview, is widespread.
The
Land newspaper this week (from its website) suggests that Australian
producers are likely to reject GM canola, but this is almost
certainly due to the marketing issues created by the very effective
anti-information campaign run in Europe. As a marketing
decision, it probably has merit - the loss of yield from using only
non-GM varieties is probably only 0.5t/ha and the market
advantage could be considerable.
The
gene for resistance to glyphosate-resistance is now found in half a
dozen countries and in most of the major crops. It is naturally
occurring. I am not sure that encouraging its propagation is
responsible, but merely using glyphosate will do that. It is
irresponsible of the companies involved to say that there would be less
herbicide used overall if you use their Roundup-ready variety, because
this is not true in the long-term. But the plain fact is that
there is a battle between farmers and weeds, which has a genetic aspect
to it and always has. GM crops are just another tool.
As
to the danger of GM oil crops, well... I am afraid as Australia has
been importing about half of its edible oils for years, then most
Australians have eaten significant quantities of GM oil... it is in
nearly every manufactured food, it seems and the oil produced in the US
has used GM varieties for several years. There are a few
manufactured foods that advertise that the oil from GM free crops, but I
wonder if the effort is worthwhile.
Incidentally,
Wolfie claims to have lost all interest in science since leaving the
list, but there is an argument that he was never
interested in SCIENCE in the first place.
Zero Sum wrote:
> > Please do not jump up &
down on this old bloke but - how is
> > "engineering viruses" different from "engineering crops"?
> Possibly because qualified scientists could be concerned about
risks
> from the virus, but few without an axe to grind would carry on
about
> GM canola. A scientific case could be made for the virus
doing
> harm -- I am not saying it would be a feasible case, but one could
be
> made, and it needs to be shown to be improbable. There IS a middle
> ground, and that is where we will end up.
With canola,
that is probably fine, but with engineered viruses there is currently no
middle ground. Since we lack the technology to deal with viruses
(it wasn't technology that beat SARS - iff beaten - but plain old
fashioned medecine) in a safe and secure manner, we would be wiser to
avoid any risks, even potential ones.
[snip]
> Google "golden rice", which the loopies hate, because it only has
> benefits, is not owned by Big Agribusiness, and it saves
lives. they
> accuse the scientists of "cheating" by doing good, and say it is
only
> done with malicious intent, in order to get GM accepted. They would
> rather see people starve (here, sadly, I have to agree with Dubya,
> though I doubt that we share many motives).
Just a
question...
If the genes for
golden rice do get spread uncontrolably will we have to give up eating
rice to avoid hypervitimanosis? I'm not against it (golden rice)
or GM in general. I do think that we must take almost infinite
pains with it as the consequences...
>
With no self-promotion intended, may I refer you to
> http://www.abc.net.au/rn/science/ockham/stories/s289416.htm where I
> explore the way technologies advance? GM is too new, and we
have no
> way at all of knowing what the benefits of a new industry may be,
and
> even less of guessing what the disadvantages will be. (With full
> self-promotion intended, I will bury here the note that a book
called
> "Rockets: Sulfur Sputnik and Scramjets" is to be let loose on the
> world on July 11, and it also uses this question of how
technologies
> mature and produce unexpected effects.)
Yes it is new,
very new, and we have yet to learn what all the problems will be.
Even the use of asbestos was once new...
Our history
contains a list of disasters caused by new technology (maybe the first
was agriculture) and as our new technologies become more powerful it
behooves us to take greater and greater care.
>
> At the risk of being flamed, would you accept GM humans eg
> > - introducing genetic material into developing human embryos
to
> > introduce "natural immunity" to diseases affecting humans,
such as GM
> > sickle cell anaemia to provide immunity against malaria
>
This is gene therapy, and yes, I would be inclined to do accept it in
> the long term -- but not just yet, as there have been a number of
> cases of unusual cancer associated with attempts to treat children
> with SCID (severe combined immunodeficiency disease) -- Google
those
> names or Alain Fischer at the Necker Hospital. In this case, it may
> have been the carrier that was used -- last I saw, nobody was
certain,
> but there were definite suspicions.
>
> Be aware that SCID is not necessarily a fatal condition IF a
> perfect-match bone marrow transplant can be arranged, but finding a
> suitable donor may not be easy, and as many as 30% or 40% of
victims
> die of the disease. On that basis, it was deemed appropriate to
try,
> but once the cancer cases started to show, the trials around the
world
> were stopped.
Hang fire, this
is a really bad example to use. Sickle cell anaemia is either
beneficient or otherwise depending on the environment. Eliminating
it or giving it to 100% of the population would decrease the viability
(and adaptability) of our species, would it not?
>
The whole matter is a slippery slope -- do we then modify a tennis
> player's genes to give him/her longer arms?
You don't.
There is no point.
>
My long bones are two standard deviations shorter than they ought to be
> for my body size --
Have you been
check for diabetes recently? A shorter humerous (by only one
standard deviation) is apparently a strong indicator for the development
of type II diabetes. Better get that checked out.
>
it is not dwarfism, but causes a few MINOR annoyances -- like having
> trouble reaching my toes. Should I get the arm and leg lengthening,
> but not the tennis player? Or should we modify trees to produce
more
> cellulose and less lignin to generate 'greener' paper? Maybe we
would
> be better concentrating on finding alternatives to paper?
Since arm and
leg length is not going to be know until close to maturity, there isn't
much you can do about it in the adult organism.
With the paper,
obviously the less energetic solution the better.
>
> In case I have upset/annoyed some supporters of GM
> > technology/science on this Forum, please remember that the
old bloke
> > you flame is somebody's granddad.
>
Speaking as one of the more rabid pro-GM advocates, the questions you
> raise should not provoke flaming, nor should an expressed opinion
> based on an ethical stance. In the end, people started shouting at
> Wolfie because he kept raising the same issues, even when they had
> been answered, a bit like the creationists. If you raised
the "tomato
> with fish genes" story, and were told that it never existed, and
you
> kept asserting that it did, with no evidence, then people might
get a
> bit frosty, rather than flaming you.
I always thought
that people were a little hard on Wolfie. he lacked the experience
in science to express his point properly and got repeatedly trashed for
expressing it poorly. The bottom line for Wolfie was that he
didn't want risks taken on the say-so of people (scientists) who had
repeatedly made blunders in the past. That is quite rational as I
see it.
He no longer trusts scientists.
Possibly with good reason.
There are some
risks you do not take even when you are sure,simply because you
may have made a mistake and the potential consequences of that mistake
are to severe to be ignored.
Prince Charles
has good reason to be worried about nanotech "grey goo".
Eventually we will be able to build such. Only the insane
would actually do so but we have plenty of them around (even running
countries).
[snip]
> Hopefully, by then the facts will be agreed and understood.
That
> agreement and understanding will not come from brutally beating
down
> the questioners.
The facts may be
agreed and understood but the risks are always an opinion, as are the
magnitude of the consequences. Some people may consider that a one
in ten billon chance of wiping our species out is just fine.
Others won't.
Peter
Macinnis responded:
>
With canola, that is probably fine, but with engineered viruses there is
> currently no middle ground. Since we lack the technology to
deal with
> viruses (it wasn't technology that beat SARS - iff beaten - but
plain old
> fashioned medecine) in a safe and secure manner, we would be wiser
to
> avoid any risks, even potential ones.
yes
-- I meant a middle ground between the virus on one side and GM stuff
on the other. The most effective SARS treatment, at cost to the
medical staff involved, was that undertaken in Vietnam, where they
nailed it down and splatted it in isolation.
>
Just a question...
> If the genes for golden rice do get spread uncontrolably will we
have to
> give up eating rice to avoid hypervitimanosis? I'm not
against it (golden
> rice) or GM in general. I do think that we must take almost
infinite
> pains with it as the consequences...
From
memory, the makers took that into account -- not with wild spread of
many genes (unlikely), but people consuming too much rice. Golden rice
makes only the precursors of vitamin A, so no probs -- as I recall it.
>
Yes it is new, very new, and we have yet to learn what all the problems
> will be. Even the use of asbestos was once new...
If
we knew how many people cars would kill, would we allow them if they
were proposed?
>
Hang fire, this is a really bad example to use. Sickle cell
anaemia is
> either beneficient or otherwise depending on the environment.
Eliminating
> it or giving it to 100% of the population would decrease the
viability
> (and adaptability) of our species, would it not?
That
is why SCID was a good example to use. Have we the right to say
"No, sorry, we need you as a parking spot for genes that are bad for
you, but MIGHT be needed later?" that is where you come to casuistry,
sophistry, and all the other value-laden arguments. Your question
will need to be asked, though.
> > My long bones are two
standard deviations shorter than they ought to be
> > for my body size --
> Have you been check for diabetes recently? A shorter
humerous (by only one
> standard deviation) is apparently a strong indicator for the
development
> of type II diabetes. Better get that checked out.
There
is a family history of diabetes, but mine appears to be environmental
rather than genetic -- I was a wartime baby, subjected to gin, nicotine
and other undesirable items, which may have something to do with it.
>
Prince Charles has good reason to be worried about nanotech "grey goo".
Perhaps
because his head is already full of it? I don't accept that a
dysfunctional inbred pampered upper-class twit with no qualifications
has a valid role here.
Zero Sum replied:
On Wed, 25 Jun
2003 10:58, Peter Macinnis wrote:
> > Prince Charles has good
reason to be worried about nanotech "grey
> > goo".
> Perhaps because his head is already full of it? I don't
accept that a
> dysfunctional inbred pampered upper-class twit with no
qualifications
> has a valid role here.
Grr... You
snipped the "why"...
If you have a
disinclination for pampered upper-class twits, then you must have
contempt for a lot of histories scientists. Ad hominem does not
cut it.
and :
On Wed, 25 Jun
2003 11:13, Podargus wrote:
>
It can be equally argued that the fact that you have reached your
> advanced age in good health, and a with a great standard of
living, is
> the result of these 'nasty experiences. What bit do you
eschew?
The bit that our
children and grandchildren will have to (or fail to) endure.
Peter
Macinnis added:
Lunchtime,
and this just in form Guy Nolch at "Australasian Science":
GM
Benefits Don¹t Outweigh Risks: Survey of Canola Farmers
A
survey of canola farmers has found that they do not support genetic
modification of the crop. Published in the July issue of Australasian
Science magazine, the survey found that genetic modification of
agricultural produce was only supported if it ³demonstrated
specific agricultural benefits, such as resistance to fungal
disease².
In
contrast, ³canola modified to be herbicide-tolerant was considered
unacceptable by a majority of respondents regardless of its potential
benefits. A majority of respondents (70%) felt that the benefits of
herbicide-tolerant GM canola did not outweigh the risks, and were not
willing to support it.²
The
survey was conducted by Anne Parkinson, a PhD student at La Trobe
University¹s School of Social Sciences, and Dr Richard Hindmarsh of
Griffith University¹s Australian School of Environmental Sciences.
They
write: ³The survey is unusual because the traditional focus on GM
opinions has been on consumers, not producers. Yet, producers occupy a
crucial position in the marketing of GM crops if they¹re not
willing to grow GM crops then GM crops will not be sent to market unless
GM corporations pursue direct farming, which seems highly
unlikely.²
Parkinson
and Hindmarsh write that ³canola farmers do not support growing GM
canola for three main reasons:
- export markets may increasingly reject GM produce;
- herbicide tolerance may spread to both non-GM crops and weeds,
and the latter will become more difficult to control and will also
result in more chemical use; and
- concerns with increasing corporate ownership of the technology
and a potential loss of farmers¹ autonomy.²
Parkinson
and Hindmarsh say their findings ³align with the concerns of many
farmers¹ organisations. With Tasmania, Western Australia and NSW
placing moratoriums on the commercial release of GM food crops, and
Victoria recently placing a 1-year moratorium specifically on GM canola,
the findings of the survey thus appear significant and to be in
accordance with current trends.²
Please
cite AUSTRALASIAN SCIENCE MAGAZINE as the source of this story.
Podargus posted, in reply to a previous post by Peter Macinnis:
>
We have a budding biotechnologist in our house, and we were discussing
> methods over dinner last night -- he referred to the use of 'grass
> organisms' - 'grass' being GRAS, generally regarded as safe.
If you
> are modifying a lactobacillus to make better yoghurt, you cannot
> source genes from E. coli, you cannot even use an E. coli promoter
--
> the whole industry is based on being doubly safe. This was news to
me,
> and I'll bet it would be news to most of the protesters.
The use of
modified lactobacillus for yoghurt was news to me until I did some
research for an article on GMOs. The implication was that all/most
yoghurt used it, I didn't need to look deeply into it at the time, do
you or your colleague know how widespread the use is?
Peter
replied:
>The
use of modified lactobacillus for yoghurt was news to me until I did
>some research for an article on GMOs. The implication was
that all/most
>yoghurt used it, I didn't need to look deeply into it at the time,
do you or
>your colleague know how widespread the use is?
Well
I got it wrong -- it was Lactococcus, not Lactobacillus, and apparently
the work is being done by DMM at Moorebank -- happy Googling!
Duncan
is not sure how common the GM versions are.
Jason Chantarat
posted:
How do you stop
the wind blowing the GM seed into areas where it is not wanted by
traditional farmers?
Hi everyone
This is a rather
naive comment coming from my view on GM crops.
"Why not just
'genetically modify' the crops so they won't blow with the wind...
quite simple
really..."
Peter
Macinnis replied:
Not
naive, fresh -- and since when was naive, unblinkered thinking bad in
any case? Funnily enough, I learned this week that it is possible
that there may be a solution. It is all rather complex, but it
involves inteins, where one half of the required gene is in the
chloroplast, which does not travel with the pollen -- like mitochondria
coming from Mum, chloroplasts also come from the ovum only. The
pollen can never transfer the gene.
I
started reading up on this last night, and planned to master the
methodology of this technology and pass my account to the list
sometime
next week -- if anybody knows much and weighs in early, that may save
me some brain frazzling. It is another neat bit of work my son has
passed on to me.
The
intein route also makes transfer by any of the other lateral transfer
routes less likely as well.
More
when I know enough of what I am talking about. The stuff in
"Nature" is bad news, there is some easier stuff in "Science".
and:
At
16:08 26/06/03 +1000, I wrote:
>Funnily
enough, I learned this week that it is possible
>that there may be a solution. It is all rather complex, but it
>involves inteins, where one half of the required gene is in the
<snip>
>I
started reading up on this last night, and planned to master the
>methodology of this technology and pass my account to the list
>sometime next week
Well,
next week came a little early. I am still a bit shaky on this, so
any expert advice on how to clarify matters will be welcome, and I can
only undertake to answer questions as well as I can. This should
give readers the general idea -- and it is certainly easier to read than
the stuff I have ploughed through today. My thanks to my son,
Duncan, who filled me in, trained me up, and turned me loose.
I
would also welcome any helpful Web resources.
******************
TECHNICAL:
skip over this if you wish, and come back later.
Inteins
occur primarily in yeast, algae, viruses, bacteria, and archaea, and
they are pieces of protein that break free when the section of protein
on the carboxyl end of the intein, the so-called C-extein, grabs onto
its N-extein counterpart and tears it off the intervening intein,
attaching it to itself. The intein then cuts itself loose from the newly
connected exteins. The reaction is spontaneous, occurring as soon as a
protein folds.
The
first intein was discovered in 1987 (or 1990, depending on who tells
the tale), and a search on the Web reveals remarkably little helpful
information about the inteins. A good technical reference of about 20
pages: www.sp.uconn.edu/~gogarten/bioinf/InteinReview.pdf,
where one can read:
"Inteins
(internal proteins) are genetic elements similar to self-splicing
introns; however, inteins are transcribed and translated together with
their host protein. [Introns are not transcribed.] Only at the protein
level do the inteins excise themselves from the host protein. The two
portions of the host protein separated by the intein are called exteins
(external proteins). . . . During the splicing process the intein is
excised, the two exteins are joined by a peptide bond, and the host
protein assumes its normal folding and function."
There
is a technical database at www.neb.com/neb/inteins.html
, and Francine Perler and Ming Xu are two of the leading researchers, so
their names may be worth Googling. A brief paper in 'Science' for June
13 by Ingrid Wickelgren is worth accessing. Volume 300, Number
5626, Issue of 13 Jun 2003, pp. 1646-1649. She has a bit more on
the PNAS paper cited below.
GENERAL
Let
us turn now, a little eccentrically, with the notion of an intron,
often referred to as 'junk DNA', sections of DNA that are spliced out
when DNA is being transcribed to RNA. When similar pieces of 'junk
protein' were discovered, it seems they were dubbed "inteins". We can
ignore the introns now, as their only role here is in providing a name.
We cannot, however, ignore the inteins.
Inteins
are pieces that are attached to two component sections of protein that
need to be linked together to make a working protein. The two proteins
may be specified on nuclear DNA, chloroplast DNA or mitochondrial DNA.
If they come from different parts of the cell, they are referred to as
'split inteins', and it is these split inteins that we need to look at
most closely.
The
important thing to note is that the two halves of the protein do not
need to be coded for in the same place: they have no problem with being
split inteins. They can come from different chromosomes, or one may come
from a chromosome while the other comes from DNA located, for example,
in the chloroplast. When the two halves come together, the 'junk' parts
line
up
against each other, and also align the active parts, so when the 'junk'
pieces break off and drift away, a new protein is left behind, ready to
play a role in the cell.
Now
keep in mind that just about everything happening in the cell is under
the control and direction of proteins. If a plant is to be
herbicide-resistant, or to make a vitamin, a special protein needs to be
made, an enzyme that has just the right shape, size, and charge
distribution to control a reaction. The protein is made of a string of
amino acids, a polypeptide, that folds up in just the right way, so as
to make the proper shape. When the intein portions are clipped off, two
remnants remain which can fold up into just the right shape, delivering
a new enzyme.
Now
we need to consider the nature of pollen grains and sperm cells. Sexual
reproduction is an effective basis for evolution because it produces
reasonable numbers of offspring, and gives them all a freshly shuffled
set of genes to work with, so as to bring about new combinations faster.
Over time, evolution has favoured those organisms which develop a large
cell, the ovum, loaded with extra food and other useful bits and
pieces, and stripped-down sperm and pollen cells, carrying half the
standard number of chromosomes only.
Most
of the sperm cells and pollen cells are destined to be wasted, and they
are produced in amazing profusion. If they were larger, they would
travel more slowly, and all the 'extras' would be wasted in almost every
case. It gives a better advantage for organisms to produce male sex
cells, pollen and sperm, with a bare minimum load to carry. The extra
bits that our cells need come from the ovum.
Most
biologists now accept serial endosymbiosis theory, which suggests that
our complicated cells arose from several components, so that the
presence of genes in the chloroplasts of plants and in mitochondria is
easily explained: these were once independent organisms that fused
together to form a stronger unit. The process of sexual reproduction may
well have evolved before our ancestors added in the new residents, but
they got around it by ensuring that the residents always travelled with
the ovum.
A
major concern with genetically modified organisms has long been that
pollen grains can travel long distances with insects or on the wind, and
carry GM genes with them, causing what opponents of GM love to call
'contamination'. They then go on to argue that herbicide-resistant
canola, for example, produces contaminated canola oil, which is somehow
unclean and perverted. This is, of course, entirely without a sound
basis, and goes to show how the opponents of GM, in their ignorance,
take no notice of the REAL concern that they should be expressing.
Many
crops are closely related to plants that we now regard as weeds, and
plants have much weaker barriers to the interchange of genes from one
species to another. It would be a serious problem if those weeds were to
acquire herbicide-resistance from crops, and that is a likely situation
if pollen just blows around anywhere, carrying the genes with it.
'Contaminated' crops are not the problem, but weed-resistant
weeds ARE. Of course, as far back as 1997, the weed rye grass had
evolved a natural
resistance
to glyphosate (or 'Roundup'), so the herbicide will eventually cease to
be of use against weeds, but it would be nice to keep using glyphosate
for as long as possible, since herbicide farming is far more
soil-friendly than conventional tilling, but it relies on having crops
that are unaffected and weeds that are affected.
So
there is a good and valid scientific reason to limit the spread of GM
genes. Added to that, there is a good political reason to do so, because
it will stop the protesters from carrying on about their precious
'contamination'. At the very least, this might release their minds to
look again, and identify genuine problems with GM methodology. Science
is not above being questioned, but right now, it is not being
questioned, just slandered, because those who should be questioning know
no better.
Now
we need to turn back to the inteins, and why they are of interest here:
if a split intein that delivers herbicide resistance can be engineered
so that one half is in a chloroplast, and the other half is in the
nucleus, the likelihood of a whole resistance gene ever being delivered
becomes vanishingly small, on a par with being hit simultaneously by two
asteroids from two different directions. Even if the entire chloroplast
half of the gene were to be transferred to a host plant, it would need
to get into the tiny
number of cells that become ova, and it would need to be fertilised by
a pollen grain carrying the other half.
I
originally wrote that as yet, this is merely a theoretical hope, but
the potential is there for some remarkably clever work. Now I find
that Sriharsa Pradhan's team at New England Biolabs (where most of the
best work is going on -- they mainatin the database cited above) has
already conferred herbicide resistance on tobacco plants. They attached
one of two parts of an algal intein to each half of a
herbicide-resistant gene, they report in the 15 April Proceedings of the
National Academy of Sciences. One fragment went into the chloroplast
genome, the other into the nucleus. The intein-containing
fragments reassembled in the chloroplast and spliced to yield an intact
protein that protected the plant.
**************
Well,
you can guess which encyclopedia is going to be the first on the block
with this topic. Happy reading!
Chris
Forbes-Ewan wrote:
Going over old
mail, to discard it or place it in folders as appropriate, I came across
the following question from Zero Sum (Sent: Wednesday, June 25, 2003
10:41 AM)
>
If the genes for golden rice do get spread uncontrolably will we
> have to give up eating rice to avoid hypervitimanosis?
The unequivocal
answer to this question is 'no!'
Golden rice
provides beta-carotene, also known as provitamin A. The body regulates
the conversion of carotene to vitamin A according to its vitamin A
status--if you are deficient in vitamin A, carotene will be converted to
the active vitamin at the maximum rate. If you already have adequate
vitamin A, the conversion rate is reduced accordingly. So
hypervitaminosis A will never occur as a result of eating Golden Rice.
Zero's message
also contained:
>
Our history contains a list of disasters caused by new technology
> (maybe the first was agriculture) ...
Our history also
contains a lot of successes due to technology (maybe the *first* was
agriculture).
>
A shorter humerus (by only one standard deviation) is apparently
> a strong indicator for the development of type II diabetes.
Do you have a
reference for this? The only anthropometric variable associated with
type 2 diabetes that I know of is obesity (and the association is very
strong in this case).
David
Allen added:
But,
this brings to mind the extensive and now well publicised study of a
decade or so ago; curtailed due to some adverse reactions detected as a
result of imbibing beta-carotene in isolation from other phytochemicals
normally accompanying it in nature, it is suspected.
I
wonder if these other phytochemicals which appear to be synergistic
with b-c are present in appropriate quantities in 'Golden Rice'? It
seems unlikely as, as far as I know, such chemicals and their synergies
have not even been identified.
........."Conflicting
results on beta carotene point out the need for many studies before
epidemiologists and other specialists can recommend dietary supplements
to reduce cancer risk. By looking at people's diets and comparing cancer
rates among different ethnic and geographic populations,
epidemiologists are working to get clues that may help identify cancer
inhibitors and, thus, further refine dietary recommendations. Because
large population studies are never exactly the same -there may be a
different
population
group, different cancers, or a different combination of food and
nutrients - public health specialists look at the total body of evidence
before drawing conclusions.
"...........
http://www.biorap.org/rg/rgcancerdietfact.html
http://www.diabetesselfmanagement.com/article.cfm?aid=978&sid=6
refer,
amongst others.
Zero Sum
replying to Chris Forbes-Ewan:
>
Our history also contains a lot of successes due to technology (maybe
> the *first* was agriculture).
You know I am
not an anti-technologist. I'm merley pointing out that it is a two
edged sword (as are all things).
> > A shorter humerous (by only
one standard deviation) is apparently
> > a strong indicator for the development of type II diabetes.
> Do you have a reference for this? The only anthropometric variable
> associated with type 2 diabetes that I know of is obesity (and the
> association is very strong in this case).
Unfortunately,
no. It was something I came across in my reading into diabetes to
discover what I need to know. It is on the web somewhere. As an
aside, it fits perfectly with my family (both sides).
Chris
Forbes-Ewan wrote, in response to David Allen's comment:
We're
getting away from the point of Zero's question, which was along the
lines of what would happen if the gene for beta-carotene in Golden Rice
were to somehow spread through all varieties of rice.
In
the very unlikely event that this did happen, the point I was making is
that hypervitaminosis A (i.e. toxicity due to excessive vitamin A
ingestion) will not be a problem.
David's
point about high levels of supplementary beta-carotene being associated
with increased cancer risk is valid, but not relevant to this
discussion. Golden Rice will not provide a high level of beta-carotene
intake. In fact, one of the criticisms by the anti-GM lobby is that
Golden Rice is a relatively poor source of vitamin A (or rather of
beta-carotene, the most common form of pro-vitamin A).
The
Australian Recommended Daily Intake of vitamin A is 750 micrograms per
day for adults. Golden Rice provides about 2 micrograms of
beta-carotene per gram of rice. The conversion rate of beta-carotene to
vitamin A is not known exactly, but estimates range from 1:6 to 1:12
(i.e. between 6 and 12 micrograms of beta-carotene are required to
produce 1 microgram of vitamin A).
Eating
200 grams (before cooking)--a large quantity by western standards--of
Golden Rice would provide you with about 400 micrograms of
beta-carotene, which is the equivalent of (at most) ~70 micrograms of
vitamin A. This is about 10% of the recommended daily intake. It is
enough to make a difference if you are vitamin A deficient (as hundreds
of millions are in developing
countries), but it is nowhere near enough to be toxic.
