Knowledge of the molecular basis of life has advanced a lot in recent decades. Public understanding of this science has lagged, which has led to misinformation and disinformation taking root in people’s minds. For example, ‘‘genetically modified food’’ might conjure up an image of a hybrid of a salmon and a cucumber.
The science is simple. A gene is just a stretch of DNA that gives an organism a particular attribute - such as red hair or the ability to digest a certain food.
Genes are the recipes for proteins. The tools of molecular biology let us work out the DNA sequence of any organism (genome sequencing), change the sequence of any gene (and therefore the protein it makes), and take DNA from one organism and introduce it into another (making a GM organism).
Our research group (based at the University of Sydney) used these tools every day. We made mutant genes for proteins that can have pathologically abnormal shapes, made GM bacteria and other organisms to produce these mutant proteins and then studied their properties. Our work has helped in the understanding of incurable diseases such as diabetes, Parkinson’s and Alzheimer’s.
There is some hysteria about ‘‘frankenfoods’’ - foods that derive from GM organisms.
This is nonsense - any time somebody who is not an exclusive cannibal eats a meal they will ingest non-human proteins. There is no difference between eating a tomato containing a GM protein from fish, for example and eating an unmodified tomato with a piece of fish - in both cases there will be a mixture of tomato and fish proteins in your gut. A protein may or may not be toxic but whether it is in a GM food is irrelevant to that question.
Feeding the world’s growing population is a big challenge; the world will need 70 to 100 per cent more food by 2050. GM crops can make an important contribution to this.
Drought-resistant GM maize crops are in advanced field trials in the US; this technology will become increasing important if climate changes occur as predicted.
Much plant food is lost through weed or insect infestation. GM crops, resistant to herbicides and/or predatory insects, are part of the solution. In the US, a minimum of 86 per cent of cotton, canola, alfalfa and corn crops have been modified in this way. A recent report concluded that this was a positive development.
For example, vitamin A deficiency affects about 120 million people, mainly in Africa and South-East Asia. It is responsible for 1 to 2 million deaths each year because vitamin A is important in ensuring that the immune system can fight off infections. GM rice (‘‘golden rice’’), which makes high levels of a vitamin A precursor, will help - it is scheduled for release in 2012.
In Australia there are robust regulatory mechanisms for GM foods. They require approval from Food Standards Australia and New Zealand and the use of molecular biology methods in research requires approval from the Office of the Gene Technology Regulator. Neither have any commercial affiliations and both are tough - the OGTR regularly arranges ‘‘surprise’’ visits to labs where molecular biology methods are used to check that rules are being followed.
GM plants and animals are only part of the story. DNA fingerprinting is now a major part of forensic biology. Soon any human genome will be able to be sequenced for less than $1000. That sequence will allow assessment of genetic risk for many diseases, while GM is used in treatments and vaccines for a range of diseases.
Most of the insulin used to treat people with Type I diabetes is made in GM yeast. The HPV vaccine, which protects women against cervical cancer, is made using GM methods.
There are ethical issues here. For some non-adoptive children, the man they know as their father is not their biological father. That is easy to establish using DNA fingerprinting. Who should have access to that information?
Who should have access to your genome sequence - your GP, your life insurance company, your employer?
Research grants using molecular biology tools are awarded based on the opinions of professional assessors. Should there also be lay grant assessors to assess the ethics of the application of those tools?
Farmers who plant GM crops may be beholden to the commercial companies who made the GM seeds. What are the ethical duties in this relationship?
The Nobel prize-winning chemist Robert F. Curl said that the 20th century was ‘‘. . . the century of physics and chemistry. But it is clear that the next century will be the century of biology’’. He was talking about molecular biology. Like it or not, he is right, the more people learn about molecular biology, the better informed public debate will be.
Around the science webs:
About a million people a year die from malaria. Mosquitoes transmit the malaria parasite from person to person. GM mosquitoes resistant to malaria have been made in the lab; a recent report shows how this resistance can be spread efficiently in wild mosquito populations.
Multiple sclerosis is an incurable disease of the nervous system. It seems that a combination of lack of exposure to the sun combined with glandular fever is a major risk factor for it.
Every year more than 10000 Australians are treated for melanoma and about 1500 die from it. Molecular biology in action has identified a novel mutant gene, important in melanoma, which is a promising therapeutic target.
Drought is a perennial part of Australian life. The Antarctic ozone hole seems to be about one-third to blame for Australia’s recent series of droughts.
Dr Simon Easterbrook-Smith is a biochemist who worked for many years as a teaching and research academic in the school of molecular bioscience, University of Sydney. He is a member of the Australian Society for Molecular Biology and Biochemistry.
Copyright © 2011 Fairfax Media
