Scientists have discovered a method to turn the dangerous dengue-transmitting mosquitoes into harmless insects: changing their sex. An US research team has successfully isolated a gene that can be manipulated to turn the deadly females into harmless males.
The gene was identified by researchers from Virginia Tech’s Fralin Life Science Institute. The team also suggested that they have developed the required technique to ensure that the gene can be effectively pushed into the next generation of mosquitoes.
However, a moral dilemma emerges. The mutation will make the mosquito population produce exclusively males, leaving it with no means to reproduce. Just because the scientists have the means to completely exterminate the dengue-transmitting mosquitoes, this doesn’t mean they should do so.
“If you release such an animal, it only produces males until eventually the population crashes,” argued Zack Adelman, one of Virginia Tech’s molecular biologists. “We need the technology to control these systems before that can be used.”
What makes female mosquitoes so dangerous is that they are the only individuals of the species who actually bite, since they need the blood in order to sustain egg development. Researchers argue that limiting the number of females would drastically limit the transmission of several potentially deadly diseases, such as dengue, yellow fever and chikungunya viruses.
The gene responsible for the sex switch, called by the scientists Nix, is relatively easy to play with. After injecting the gene in mosquito embryos, about two-thirds of the females have developed male reproductive systems.
“Nix provides us with exciting opportunities to harness mosquito sex in the fight against infectious diseases because maleness is the ultimate disease-refractory trait,” believes Professor Zhijian Jake Tu. However, the researchers argue that until they come up with a method to control the procedure, the strategy cannot be applied.
All the scientists have now is the foundation for future control over the disease-transmitting insects. The dengue-transmitting mosquito menace should be contained, the team argues, but not at the expense of their complete extinction.
The dengue-transmitting mosquito, or Aedes aegypti, is one of the few species that are actually responsible for transmitting pathogens to humans. However, the mosquitoes are very dangerous due to the fact that they can easily adapt to various human environments, and their spreading has stepped up significantly since they were first brought from Africa in the 18th century.
The British biotech firm Oxitec has suggested the possibility of releasing an experimental genetically modified mosquito population in Florida to see how things develop. Their project, however, needs to earn FDA’s approval first.
Image Source: sintomasdadengue