Genetically Modified Mosquitoes

In News

• Recently, scientists have genetically modified mosquitoes to slow the growth of malaria-causing parasites in their guts which can also help prevent transmission of the disease to humans.

About Malaria 

• Parasites 
  • Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. 
  • The parasite develops into its next stage in the mosquito’s gut and travels to its salivary glands, ready to infect the next person it bites.
  •  Though only around 10 percent of mosquitoes live long enough for the infectious parasite to develop.
• Symptoms
  • People who have malaria usually feel very sick with a high fever and shaking chills.
• Distribution
  • While the disease is uncommon in temperate climates, malaria is still common in tropical and subtropical countries.
• Vaccine
  • It is preventable and curable.
• Data on Malaria 
  • Malaria remains one of the most devastating diseases globally, putting at risk about half of the world’s population. 
  • In 2021, it infected 241 million people and killed 627,000 people. 

Genetic modification in Mosquitoes 

• Lab-bred mosquitoes: GM mosquitoes are mass-produced in a laboratory to carry two types of genes:
  • A self-limiting gene that prevents female mosquito offspring from surviving to adulthood.
  • A fluorescent marker gene that glows under a special red light. This allows researchers to identify GM mosquitoes in the wild.
    • New tools are increasingly needed as mosquitoes develop resistance to insecticides and treatments.
• Shorter life span: The peptides impair the malarial parasite’s development and also cause the mosquitoes to have a shorter life span.
• Gene drive technology: Gene drive is one such powerful weapon that in combination with drugs, vaccines and mosquito control can help stop the spread of malaria and save human lives.  

Pros of Genetically Modified Mosquitoes

• GM mosquitoes have been successfully used in parts of Brazil, the Cayman Islands, Panama, and India to control Ae. aegypti mosquitoes.
• GM mosquitoes will only work to reduce numbers of target mosquito species and not other types of mosquitoes.
• There is no risk to people, animals, or the environment.
•  Scientists say the introduction of GMO mosquitoes will lower the population of disease-carrying biting insects over time.
• Reviews suggest the loss of invasive mosquito species will have little to no effect on local environments since they didn’t belong there to begin with.
• No pesticides are added to the environment when using GMO mosquitoes.
• Seeding areas with GMO male mosquitoes is relatively easy and a low-manpower activity.

Cons of Genetically Modified Mosquitoes

• GMO mosquitoes may carry or develop unknown pathogens that hurt humans.
• Critics say there has not been enough testing and observation of the GMO mosquitoes.
• Though the mosquito is an introduced species, native species are now reliant on these mosquitoes for their diet.
• GMO mosquitoes may mutate into a stronger mosquito that can reproduce, which poses a whole new threat.
• Fear that despite the gene modification, some of the hatched GMO mosquitoes will survive to adulthood and breed.
• The cost of producing GMO mosquitoes is too expensive and too time-consuming.

Way Forward/ Suggestions

• Planning: It would require extremely careful planning to minimise risks before any field trials.
• Two separate strains: there is a need of creating two separate but compatible strains of modified mosquitoes one with the anti-parasite modification and one with the gene drive.
• Integrated mosquito management: 
  • Educating the community about how they can control mosquitoes in and around their homes.
  • Conducting mosquito surveillance (tracking and monitoring the number of mosquitoes, and types of mosquitoes in an area).
  • Removing standing water where mosquitoes lay eggs.
  • Using larvicides and insecticides to control mosquito larvae, pupae, and adult mosquitoes.
  • Monitoring how effective mosquito programs are at reducing numbers of mosquitoes. 

Source: IE