Mosquitoes carry malaria (疟疾), which kills thousands of people each year. Now some researchers are trying to use genetic engineering to make the annoying insects into partners in the fight against the disease.
For years, public health officials have tried to limit the disease by controlling mosquito populations. “But that approach is temporary,” says Anthony James, a professor of biology and genetics at the University of California, Irvine, “Because mosquitoes are extremely tough little insects, and their populations can quickly rebound.”
Therefore, James and his colleagues want to try a different approach: making mosquitoes themselves into malaria-fighting warriors, which is a complete departure from traditional ways of controlling malaria.
To understand how it works, it helps to understand the life cycle of malaria. The malaria pathogen (病原体) is a parasite (寄生虫) that grows inside humans. It’s passed via mosquitoes that move from person to person, sucking blood. “If we can make the mosquitoes difficult for the pathogens to survive, we can wipe out the disease,” he says. But making mosquitoes uninviting to malaria is a tough job.
To solve the problem, the team used a gene-editing technique called CRISPR. They started with genes from mice, whose immune systems do fight human malaria, engineered those genes, and then gave them to the mosquitoes.
It turned out the malaria-fighting antibodies which gene-edited mosquitoes produced worked very well. They reduced the number of parasites in the mosquito before they were passed to a human host.
James’ team are now working on planning a field trial, which he hopes could be conducted on an island or in another isolated location.
But genetically changing wild animals does not sit well with environmentalists. “There’s no need to engineer a mosquito,” says Dana Perls, senior program manager for the emerging technology program at the non-profit Friends of the Earth. Perls points out that naturally occurring methods for reducing malaria appear to be showing promise, as does a new vaccine (疫苗) against the disease. “Why take unnecessary risks and release a species that can’t be recalled once it’s released into the wild?” she asks.
12. What can we know from the second and third paragraphs?
A.Mosquitoes reproduce quickly. |
B.Mosquitoes depart from malaria. |
C.Mosquitoes are malaria-fighting warriors. |
D.Mosquitoes’ populations are under control. |
13. According to the text, which of the following are attractive to the malaria pathogen?
A.Mice. | B.Parasites. | C.Mosquitoes. | D.Gene-edited mosquitoes. |
14. What is environmentalists’ attitude toward this new approach?
A.Tolerant. | B.Favorable. | C.Objective. | D.Disapproving. |
15. What is the best title for the text?
A.Limiting Malaria by Controlling Mosquito Populations |
B.Controlling Malaria by editing Mosquitoes’ genes |
C.Curing Malaria with Gene-edited Mosquitoes |
D.Preventing Malaria with a new vaccine |