(University of California - Riverside) To be able to reproduce and become effective disease carriers, mosquitoes must first attain optimal body size and nutritional status. A pair of researchers at the University of California, Riverside, have succeeded in using CRISPR-Cas9, a powerful tool for altering DNA sequences and modifying gene function, to decrease mosquito body size, moving the research one step closer to eliminating mosquitoes that carry dengue fever and Zika virus.