Gene Drive. You have probably not have heard of it, but it is an underestimated and certainly, understated tool that has only recently started to lift off. Scientists are excited at the prospect that finally, they may have hacked the rules of inheritance using gene drive, and hence, they may have discovered the cure to malaria.
Malaria. You have definitely heard of it. It is rife in areas such as Sub-Saharan Africa and India and unfortunately, many that do die from it are under the age of five. There has been radically improving treatment of malaria, and methods of prevention, such as using antimalarial drugs and mosquito nets and coupled by targets set by the World Health Organization, there has been steady increase in the knowledge of malaria and people’s accessibility to treatment. Yet these improvements have not reached the most affected areas, as people struggle to afford medication and cost-efficient prevention techniques. So scientists now believe it is up to them – not the people suffering the disease – to combat the evergreen crisis that is malaria, and by discovering the power of gene drive, they have taken a huge step into achieving their aim.
Essentially, a gene drive biases inheritance so that a genetic modification has a greater than 50% chance of being passed onto an offspring. The discovery of CRISPR, a powerful genome editing tool, allows scientists to build gene drive systems capable of editing almost any gene in sexually reproducing species. What scientists do is that they insert the gene editing tool itself into a particular area of the mosquito’s DNA. CRISPR then cleverly causes the cell that contains the genes to copy the tool onto the corresponding chromosome. Hence, as a mosquito reproduces, it would pass onto the edited gene to their offspring, who would then pass their genes onto their own offspring, and the occurrence of the edited gene multiplies. Over time, the edited gene would dominate the genome of the new generation of mosquitos. The edited gene could display either one of the two characteristics, which are:
- Spread female infertility, shrinking the mosquito population into obscurity
- Make mosquitos resistant to the malaria parasite, so they do not transmit it between humans
This is certainly a long-term solution, and hence any short term problems will not be alleviated. Its impacts in an ecological sense have to be considered too, as eliminating mosquitos as a whole affects the balance of food chains and ecosystems. Social considerations need to be measured against the length of research and testing too, as every year gene drive is not introduced, that means 700000 more children die. Yet the argument for scientists is that by rushing the process of testing, it may lead to errors in the modified gene, and as it is an irrevocable change, it is very hard to correct the wrongs. Also, speeding up the process is limited by money and funding, as building and labs still need to be built closer to where the new mosquitos will be released, so in Africa.
Hence, it is important to remember that whilst gene drive is a probable solution, testing for sustainability and long term use has to be prioritized before any use in the near future.
Photo Credits due to: https://www.sciencenews.org/article/gene-drives-spread-their-wings