Gene Drive Technology to Control Mosquitoes – 11-09-2023

Syllabus: GS3/Developments in Science And Technology 

In News

• With insecticide resistance in mosquitoes rising to alarming proportions, it has become imperative that newer approaches should be developed to control them.

About

• The earliest known mosquitoes from the fossil record date back at least 70 million years, and evidence of mosquito-borne diseases like malaria dates back to Egyptian mummies from 2000 BC.
• Apart from malaria, which claims the lives of over half a million people every year, mosquitoes serve as vectors for various other diseases- dengue, Zika, lymphatic filariasis, and yellow fever. 

Recent Trends

• The rapid urbanisation of the world’s populations, especially in many large and economically developing countries like India, has led to annual surges in mosquito-borne illnesses like dengue. 
• Together with climate change and its cascading consequences, mosquito-borne diseases have expanded into new territories. A notable example is the indigenous cases of dengue in France in recent years.
• Hence, mosquito control has taken centre stage today and the battle continues unrelentingly with an array of tools – from mosquito nets to insecticides and the use of symbionts like Wolbachia. 
• Further, the ability to read or sequence the genomes of organisms, and edit and manipulate these genomes, has given us new tools in this fight. Researchers have helped prepare high-quality reference genomes for Anopheles stephensi, a major malaria-vector mosquito. 

The Gene Drive Technology

• The fundamental idea behind genetic manipulation of mosquitoes is to systematically control their populations by interfering with their reproduction. The end result for mosquitoes is to selectively inherit some genes, rather than the whole inheritance.
• This technology was conceived by Austin Burt, professor at Imperial College London, in 2003.
• Here, a protein cuts the mosquito’s DNA at a part that doesn’t encode a particular sequence in the genome. This triggers a natural mechanism in the cell containing the DNA to repair it and forces the cell to incorporate a sequence, called the drive sequence, into the damaged portion.
• It focuses on reducing mosquito populations’ reproductive capabilities or rendering them sterile. As a result, the malaria parasite won’t be able to replicate inside the mosquito’s gut.

Risks Associated

• An immediate implication is that the drastic reduction in the mosquito population could alter food chains and ecosystems that involve mosquitoes. So it’s likely that the gap in the food chain could be ‘invaded’ by other mosquitoes or in fact other insects. 
• Critics have expressed concerns about unintended consequences, such as unforeseen ecological disruptions or the potential for engineered genes to spread beyond target mosquito populations.
• Since the consequences will be shared by individuals, communities, and populations, in that order, what constitutes a right decision and what processes are to be followed remains a dilemma to policymakers.

Way Ahead

• Some of the concerns associated with the gene drive are valid and require extensive data collection, close monitoring, and multistakeholder discussions surrounding the adoption of this technology. 
• Closer home, on the regulatory front, the Department of Biotechnology in India released comprehensive guidelines for genetically engineered insects. They provide a roadmap for researchers, outlining procedures and regulations for working with such insects in the country.

Source: TH