Amid global protests, scientists find a new way to control malaria by modifying mosquito sperm to produce only male offspring
Scientists can now modify mosquito sperm to produce only male offsprings
THE THOUGHT of the world being rid of mosquitoes is enough to give many a good night’s sleep. The idea is close to being a possibility. Scientists from Imperial College, London, have successfully demonstrated a genetic vector control strategy that wiped out most of the female mosquitoes in a cage. The experiment was part of a research on dealing with malaria, a vector-borne disease spread by the bite of female mosquitoes.
In June, their research paper, published in the journal Nature Communication, established that wiping out mosquitoes by sterile insect technique is possible. In the experiment, scientists inserted a dna-cutting enzyme, called I-PpoI, into the Anopheles gambiae mosquito, the most efficient malaria vector known. In normal reproduction, half of the sperms bear the X chromosome and produce female offspring, and the other half bear the Y chromosome and produce male offspring. The enzyme that the researchers used ensured that almost no sperm carried the female chromosome.As a result, the offspring of the genetically modified (GM) mosquito was almost exclusively male.
The mosquitoes were tested in a lab and it was found that the method created a fertile mosquito strain that produced 95 per cent of male offspring. This is the first time scientists were able to manipulate the sex ratio of mosquitoes. It took the researchers six years to produce an effective variant of the enzyme.
Nikolai Windbichler, lead researcher from the department of life sciences at Imperial College, says, “What is most promising about our results is that they are self-sustaining. Once modified mosquitoes are introduced, males will start to produce mainly sons, and their sons will do the same, so essentially they carry out the work for us.”
The result has generated hope as morbidity and mortality from vector-borne diseases have posed significant challenges to public health. According to the World Health Organization (who), vector-borne diseases account for 17 per cent of the global burden of all infectious diseases.The most deadly vector-borne disease, malaria, caused 627,000 deaths in 2012.Dengue—the fastest growing vector-borne disease in the world— has seen a 30-fold increase in incidence over the last 50 years.
AJIT BAJAJ / CSE