Q. What is a gene drive? Examine the opportunities and challenges of this advance in genetic technology.
Recently, DNA alteration of a small group of mosquitoes was undertaken so that they no longer carry malaria parasite. A unique process called ‘gene drive’ was put to use.
It is a genetic engineering technology through which a particular trait drives on to the entire population. Naturally, the probability of a genotype being passed is 50%. This possibility is increased using gene drive technology.
Public health and biodiversity and ecosystem conservation are two main areas where gene drive technology has potential applications.
• Vector Control: One potential application of gene drive is to reduce the burden of vector borne diseases like dengue and malaria which cause more than 7,00,000 deaths annually
o For malaria, a gene drive system can be introduced into a mosquito species reducing their capacity to transmit malaria
• Eradicating invasive rodents: Biodiversity can be protected by reducing population of invasive species on islands. Invasive species are the 2nd greatest cause of plant and animal species loss globally.
o Currently, rodenticides are used but they are costly and the process is complicated. Gene drive methods present a potential alternative in this regard. (The Predator Free 2050 Project by New Zealand govt to eliminate invasive mammalian predator species will use gene drives as a part of its efforts)
• Generations to spread through populations: The total time depends on reproduction cycle of organism, no. of gene carrying individuals introduced, efﬁciency of drive etc.
• Gene drives cannot alter asexually reproducing populations such as bacteria and viruses
• Some types of alterations would need to be continually reintroduced. For instance, a driven trait that is somewhat harmful to the organism will eventually break. New drives would be needed in that case.
• There is a worry that removing a species from the food chain could have unintended consequences.
• Genetically modiﬁed crops can be contained but animals carrying gene drives are mobile. One country’s decision to use gene drives could impact the neighbours.
• There could also be nefarious uses of the technology. A mosquito, engineered to inject toxins, could be used as a weapon.
Though it is a welcome step, sincere caution must be taken in this regard. Following safety measures can be put in place :-
• We can begin studying how the alteration might affect the ecosystem by releasing a lot of organisms that have alterations but not the drive, ideally in a contained setting.
• Driven alterations can be reversed with another drive. If something goes wrong, reversal drive can be quickly released
• Population can be immunised against gene drives if we’re concerned about drive affecting a particular set of population.
In this way, adequate optimisation can be done to make the best use of this technology