Genetically Modified Mosquitoes

Why in news?

The Department of Biotechnology (DBT) is hesitant to permit field trials to release GM mosquitoes to tackle certain diseases.

What is the initiative?

• Aedes aegypti mosquito is the carrier of diseases such as Zika, dengue and chikungunya.
• A new initiative thus aims at reducing the population of Aedes aegypti mosquito.
• It comes from the Mumbai-based company, Gangabishan Bhikulal Investment and Trading Limited (GBIT).

What is the new gene?

• Diseases such as Zika, dengue and chikungunya are transmitted when an infected, pregnant female mosquito bites somebody.
• Males do not bite and are, therefore, harmless.
• So GBIT wants to introduce a new Genetically Modified (GM) male Aedes aegypti mosquito.
• This GM insect has been bred by Oxitec, an R&D biotech company with roots in the University of Oxford.
• Oxitec has bio-engineered a transgenic male Aedes aegypti mosquito.
• This carries a new gene fatal only to female mosquitoes.

What does it do?

• The idea is to release a large number of such GM male mosquitoes into the trial zone.
• These will then breed with normal females in the wild.
• In the next generation, only the males would survive and these would breed again, with normal females.
• After a few generations, the female population will be drastically reduced.
• Eventually this cycle will result in a reduction of the entire mosquito population.

How is it justified?

• The life cycle of a mosquito is only around two-three weeks.
• So the effects of the trial should be apparent in a few months.
• Transgenic males do not bite and the modified genes are said to be harmless to humans.
• The so-called “Friendly Aedes” project launched “closed cage” trials at the Oxitec facility in Maharashtra.
• Trials have been launched in Malaysia, Brazil, and Florida as well.
• Given these, permission has now been sought for open field trials in India.

Why is DBT hesitant to approve?

• Indian policy has been very cautious about allowing the genetically modified technologies.
• DBT scientists fear that there may be unknown hazards associated with large scale trials.
• It is thus feared that it could result in harmful consequences to the environment or ecology.
• Notably, the Aedes aegypti is part of the food chain.
• During its life cycle, it is consumed by fishes.
• Also, during its early aquatic phase, it is consumed by frogs and then by birds, lizards and spiders.
• A drastic reduction in the mosquito population could thus impact prey species.
• This could also potentially result in ecological collapse.
• There is also a possibility that the engineered genes could directly harm the species that consume mosquitoes.
• More research may be required to ensure that there are no unforeseen consequences.

Source: Business Standard