Genetic engineering a ‘long way from making an impact’

Press, 13 May 1987, Page 25

Genetic engineering a ‘long way from making an impact’

PA Palmerston North Genetic engineering is a long way from making an impact on New Zealand’s export earnings, according to a molecular geneticist in the Department of Scientific and Industrial Research, Dr Tom Broad. Dr Broad, leader of the department’s Biotechnology Division animal gene technology programme, was commenting on a report from Washington that biotechnology businesses may one day own the rights to new types of gene-altered sheep, cattle and other animals. \ The report was based on a United, States Patent and. Trademark Office decision to let inventors patent animal breeds, produced through gene splicing and other reproductive techniques. Proponents of the technology say it could produce leaner cattle and lambs and more milk from cows and enhance disease resistance. Dr Broad said molecular biology was about transferring a few genes for limited characteristics. The possibilities were immense, but -so was the scientist’s ignorance of genetic processes even

'though the technology . existed to transfer genes between animals. “It is possible to improve the products animals make for us by protein engineering, but at the moment we are talking of small biochemical changes. "We can transfer a gene which makes leaner lamb, but we’re ignorant of the processes by which animals make. meat, let alone lean meat. We are at the kindergarden stage. “We are a long way away from even knowing the mechanics of moving genes around properly,” he said. There were two big unresolved challenges, Dr , Broad said. One was identifying the functions of different gene. Scientists believed there were as many as 100,000 in any given animal. The other was accurately placing genes when they were transferred. The positioning of genes in relation to each other was critical to their function, but when a gene was transferred scientists had no control over its destination. In the wrong place it could malfunction or not function at all. “It can disrupt normal genes or become dor-

mant It is a matter of pot luck. “It is possible to manipulate characteristics independently of each other but you are at the mercy of where that gene might end up. “Failure in gene transfer is very high. It is at its best in mice and there is still an 80 to 90 per cent failure rate. In sheep, pigs and rabbits we are talking of a success rate of about 2 per cent.” In other fields, such as breeding racehorses, knowledge was even slimmer. Most of the genes that had been studied affected hormones. Genes for performance traits had not been identified at all. According to Dr Broad, further difficulties in the way of genetic transfer becoming an industry include the fact that there are differences between individuals as well as between species — and even when a gene can be identified, the way it functions is still unknown. Genes are not static. They change within an individual and between generations. Another factor still unfathomed is the dominance of some genes. “All the big characteristics — meat and wool

quality, body size, appearance — we do not understand at all in the terms of genetic influence,” Dr Broad said. “We are really at a single-gene level and what we want to work with is believed to be influenced by large groups of genes.” Scientists also had not defined the relationship between genetic influence and environmental influence. The American decision to allow patents for genealtered animals has refuelled controversy about genetic engineering. Animal welfare and other groups are moving to persuade, Congress to reverse it. A prominent American critic of genetic engineering, Mr Jeremy Rifkin, forecast a “big political battle ... between corporations and people concerned about the ethics of this policy.” He said creating animal patents could lead only to “the wholesale genetic altering and mutation of animals.” Dr Broad does not agree. “I think people see the fear of a line of monsters, totally bizarre, damaging to us. What can be done for animals can be done for humans, and it is

getting abit close to home.. “People seem to fear that a race of potentially dangerous creatures might eventuate through genetic engineering in the hands of unscrupulous people. ; “Perhaps I am naive, but I do not believe there are many people like that.” ; The potential for good, he said, was enormous. i "For example, the concept of genetic therapy is becoming, reality in the United States — the transfer of genes to overcome problems. The idea is to establish a gene in the patient’s bone marrow so it can produce cells to correct deficiencies.” Some forms of muscular dystrophy could be treated that way. “But they cannot make permanent genetic change by embryo injection because they cannot control where the gene goes, so they have pulled back from that sort of work in humans because the risk is too great.” Dr Broad said there would be a technique eventually for clipping out and replacing bad genes .;. “but right now that is really just a dream.”.