Insects are the largest and most diverse arthropod group. Many insect species are agricultural pests or vectors of numerous diseases. In fact, the mosquito is the deadliest animal on the earth killing around 725,000 people per year. Traditional methods of insect population control relying on insecticides are not effective and harmful to ecological habitats. In 2003, Austin Burt suggested that gene drives would revolutionize insect population control. According to the standard Mendelian inheritance, one copy of any gene has a 50% chance in being transmitted to the offspring. A single copy of a gene drive can promote its transmission to 95% of offspring. This super-Mendelian inheritance results in the spread of a gene drive and linked cargo genes into a local population, even when their carriers are not completely fit. The recent discovery of CRISPR/Cas9 technology simplified engineering synthetic gene drives for diverse animal species. Nowadays, synthetic gene drives have been engineered in laboratory mosquitoes for population repression or replacement. In other words, the release of gene drive mosquitoes into a natural population could block transmission of a mosquito-borne disease such as malaria, dengue fever, zika, etc. by suppressing mosquito numbers or by replacing wild mosquitos for lab-engineered disease refractory counterparts. However, many gene drives induce resistance mutations that accumulate and eventually suppress the spread of gene drives. To address these concerns, the CRISPR/Cas9 technology was leveraged to develop novel systems, such as resistance-proof gene drives and precision guided Sterile Insect Technique (pgSIT). In my presentation, I will explain how gene drives force their inheritance, and discuss the current progress and future applications of CRISPR/Cas9 technology for insect population control.

Learning objectives:
1. Comprehend how CRISPR/Cas9-mediated gene drive works
2. Learn how and why CRISPR/Cas9-mediated gene drive fails