# Genome-engineering with CRISPR-Cas9 in the mosquito Aedes aegypti

## TL;DR

Scientists used CRISPR-Cas9 to edit the genome of Aedes aegypti mosquitoes, a major disease vector, making genetic modifications easier and more efficient.

## Contribution

This is the first successful application of CRISPR-Cas9 in Aedes aegypti, enabling efficient and flexible genome editing.

## Key findings

- CRISPR-Cas9 can generate targeted mutations in Aedes aegypti using RNA-DNA base-pairing for specificity.
- The system efficiently produces various mutation types through different repair mechanisms.
- Stable germ-line mutations are achievable at most genomic loci tested.

## Abstract

The mosquito Aedes aegypti is a potent vector of the Chikungunya, yellow fever, and Dengue viruses, which result in hundreds of millions of infections and over 50,000 human deaths per year. Loss-of-function mutagenesis in Ae. aegypti has been established with TALENs, ZFNs, and homing endonucleases, which require the engineering of DNA-binding protein domains to generate target specificity for a particular stretch of genomic DNA. Here, we describe the first use of the CRISPR-Cas9 system to generate targeted, site-specific mutations in Ae. aegypti. CRISPR-Cas9 relies on RNA-DNA base pairing to generate targeting specificity, resulting in cheaper, faster, and more flexible genome-editing reagents. We investigate the efficiency of reagent concentrations and compositions, demonstrate the ability of CRISPR-Cas9 to generate several different types of mutations via disparate repair mechanisms, and show that stable germ-line mutations can be readily generated at the vast majority of genomic locitested. This work offers a detailed exploration into the optimal use of CRISPR-Cas9 in Ae. aegypti that should be applicable to non-model organisms previously out of reach of genetic modification.