Malaria

According to the World Health Organization, there were 627,000 deaths reported due to malarial infection in the year 2020. Malaria is caused by a parasite called plasmodium. Due to its great adaptable power, it is of great challenge for researchers to completely eliminate the disease. 

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What is Gene Drive ?

According to Mendel 50% of the genes gets passed to the next progeny. The idea of gene drive technology was to pass genes greater than 50% into the next generation. In 2003, Burt put forward an idea of using self-gene elements (Hom endonuclease gene) for this purpose (Burt, 2003). Selfish gene elements break the chromosome which does not have them, and when cell repairs the damage, it copies itself to it. This could now enhance the percentage of organisms in the second generation to have much more of the desired gene than predicted by Mendel.

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Researchers carried out experiments on how to use a variety of selfish gene elements for the development of gene drives (Adelman et al., 2007). The next challenge faced by them was the lack of accurate tools required to cleave and insert these elements into the DNA. Then came the CRISPR technology (Cong et al., 2013). With this gene editing tool, they could now delete, insert or modify genes at targeted areas with great accuracy hence paving the way for the complete establishment of gene drive technology. 

Gene Drive & Malaria

In late 2015, two different research one by Anthony James and other by Austin Burt and Andrea Crisanti, developed gene drive modified mosquitos. Advanced knowledge in selfish gene elements and discovery of highly accurate tools like CRISPR led to an amazing breakthrough in less than four years in the area which was studied by scientists for more than 50 years. 

References

Adelman, Z. N., Jasinskiene, N., Onal, S., Juhn, J., Ashikyan, A., Salampessy, M., MacCauley, T., James, A.A. (2007). nanos gene control DNA mediates developmentally regulated transposition in the yellow fever mosquito Aedes aegypti. Proceedings of the National Academy of Sciences, 104(24), 9970–9975.

Burt, A. (2003). Site-specific selfish genes as tools for the control and genetic engineering of natural populations. Proceedings of the Royal Society B: Biological Sciences, 270(1518), 921–928.

Cong, L., Ran, F. A., Cox, D., Lin, S., Barretto, R., Habib, N., Hsu, P. D., Wu, X., Jiang, W., Marraffini, LA., Zhang, F. (2013). Multiplex genome engineering using CRISPR/Cas systems. Science, 339(6121), 819–823.