One of the interesting side effects of the new DNA technologies is the ability to tweak existing organisms to make them more what we would like. The most recent example involves releasing mosquitoes engineered to produce sterile offspring. Their larva are supposed to die before becoming adults.
Since it’s the adult females that do the biting, it’s hoped this will greatly reduce transmission of Dengue Fever.
“In April, the Institute for Medical Research in Kuala Lumpur indicated that it might release millions of male Aedes aegypti mosquitoes that have been genetically modified to produce offspring that die in the larval stage. The release of enough of the sterile males would theoretically swamp fertile wild-type competitors and crash the population…..
Oxitec integrated a genetic element, LA 513, into the DNA of the mosquitoes. This genetic modification kills any offspring in the larval stage if they are not fed the drug tetracycline. In the lab, the mosquitoes are fed tetracycline and grow in the millions. In the wild, the modified gene kicks in, and, in theory, would be able to crash the local A. aegypti population (H. K. Phuc et al. BMC Biol. doi:10.1186/1741-7007-5-11; 2007).”
The two big questions are “Is this safe?” and “will it work?”
The mosquitoes are unquestionably genetically modified organisms, and that is scary to a lot of people. It seems like this would be relatively safe since the mosquitoes are rendered non-functional by having a gene inserted that makes them dependent on an antibiotic to finish development–which they won’t get in the wild.
Will it work? Only time will tell. I very much hope it does work, since the potential for alleviating human suffering is huge. However, the critical element in all sterile insect releases is how well the sterile males compete with wild males. If the wild, unaltered males are more attractive, or better competitors, then they will mate with the females.
Preliminary studies indicate these GM males do well against wild mosquitoes in mating with females.
Keep your fingers crossed.