Genetically modified insects leave the laboratory
We have all heard a lot about genetic engineering in plants designed to give them resistance and different properties. We also heard about genetic changes in mammals designed to produce, for example, human insulin in their milk. But who needs genetically engineered insects? Well, some experimental hi-tech insects may come out of the lab: a fly genetically engineered to fight malaria; a silkworm capable of producing bulletproof suits; Moth caterpillar feeding on cotton pods designed to destroy themselves before they destroy the cotton bush.
Transgenic insects hold the promise of helping millions in the fight against diseases and epidemics that cause hunger in developing countries. However, despite the good intentions, there are scientists who warn that these guards may cause unexpected damage to humans or the environment.
Fast multiplying insects anchor the food supply chain in many parts of the world. However, the effect of genetically modified insects is only now beginning to be studied, even though the scientists are pressing to send the genetically modified insects out of the laboratory and into the wild.
Such questions are particularly important, in particular when it comes to trying to genetically change the structure of entire species (in the case of the tsa-tsa flies, the intention is that the genetically engineered, non-dangerous insects will replace the natural flies). Unlike the use of biotechnology in agricultural crops or animals used by humans, which can at least be designed so that they are controlled, the goal of most insect research is to introduce the genetic change into the natural insect population - for example, as mentioned, making the tsa-tsa flies incapable of transmitting the deadly sleeping sickness , malaria, which affects millions in Africa.
No biotechnological insect has been out of bounds so far, but in several projects it is close - an idea presented in a report published by the environmental organization Pew in the field of food and biotechnology, and which were summarized in a recently published report, calling on the US government to adopt strict standards.
"Usually biotechnology advances faster than the government's attempt to regulate it" says Michael Fernandez, PEW's scientific director. "But in this case, we have time."
No US law addresses biotechnological insects. The Ministry of Agriculture requests approval of any experiment with insects, if it may harm the plants.
Bob Rose, the USDA's chief scientist, says federal agencies can creatively classify their experiments and avoid approval. Rose said the Department of Agriculture has the authority to oversee experiments on insects that cause disease in animals. Flies and mosquitoes transmit diseases to animals, so it is necessary to bring experiments on them for approval.
Rose also said that biotech insect research is in its infancy. But he still says that severe restrictions of the type proposed by PWE will eliminate loopholes in the legislation by biotech companies.
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For example, it is not legally possible to track goldfish, and recently a goldfish that glows in the dark with a fluorescent light was put on the market, with shields transferred to it from a jellyfish, and this is because the issue of domestic animals is not within the purview of any federal agency. The Ministry of Agriculture received only one request for an open-air test of a genetically engineered insect: the pink cotton caterpillar, which was genetically engineered to destroy itself before it harms the cotton plant. The experiment may be carried out this year.
There are other experiments in the twilight zone where the goldfish is also found: for example the experiment to convince silkworms to mass-produce hard spider silk. According to its weight, this material is stronger than steel and harder than the artificial fibers that are used today for body armor, for example by the soldiers in Iraq and elsewhere. Other researchers seek to engineer honeybees to be more resistant to disease, and wild flies to cause less damage to plants.
Anthony James from the University of California at Irvine is trying to synthesize a gene that speeds up the flies' immune system, causing them to get rid of malaria parasites. Malaria affects 300 to 500 million people a year, killing over 3 million of them. Simultaneous publications of the tza-tza genome and the malaria parasite published in 2002, expanded the developments in the scientific field in which James was once the only leader.
While he doesn't think flies are a gold mine, James believes they will be important, along with drugs and vaccines, in the fight against malaria. He hopes his research will not be slowed by the concerns raised in the PEW report and elsewhere.
Thomas Miller at the University of California at Riverside, also believes in genetically engineered insects - but for him the reason is to increase the farmers' profit on healthier crops. He received a $XNUMX million grant from the California cotton industry to produce cotton-eating caterpillars that would be sexually active but unable to reproduce properly. The idea is that these insects will reproduce in the wild and insert the lethal gene instead of the gene to create offspring.
An experiment he wants to carry out in Arizona will not contain the lethal gene for now. Instead, the scientists plan to release thousands of such worms carrying genetic markers inside them to assess how their genes will assimilate into the natural population. For his part, Miller believes that many experiments are needed to assess the impact of genetically modified insects on the environment. "I have no idea. What could they do to nature." said.
Good idea with a survival problem
There are many arguments for and against genetic engineering. One of the strongest arguments in favor refers to the possibility that genetic modification of disease-carrying parasites will help in the extinction of these diseases from the world. Mainly the things are said in flies that have been engineered by researchers so that they cannot transmit diseases such as malaria and yellow fever.
But the results of a recent study by scientists from the University of California at Riverside and the University of Maryland are encouraging. The findings, reported in the journal "National Academy of Sciences Proceedings of the ", show that genetically engineered flies will have difficulty surviving in conditions outside the laboratory.
The researchers genetically engineered mosquitoes from a species that transmits yellow fever. They then checked the fertility rates of the insects, their ability to survive to adulthood and other aspects, and compared these indicators to those of mosquitoes of the same species that were not engineered.
A higher rate of infertility was found in the genetically engineered mosquitoes. In addition, they produced on average fewer eggs than the normal mosquitoes, and the proportion of adult mosquitoes that developed from their eggs was lower compared to the non-transgenic mosquitoes. The findings mean that if the genetically engineered mosquitoes were released into the wild, they would lose out in competition with their more robust cousins.
This is a problem, because the hope inherent in mosquito breeding is that they can be released into the wild, where they will crowd out the disease-carrying non-transgenic mosquitoes. The researchers write that it is necessary to engineer the mosquitoes more carefully so that the changes do not harm their ability to survive.
