The search for the aldehyde receptor: Understanding the preference for biting humans in the mosquito Aedes aegypti

Aedes aegypti is a pan-tropical mosquito that vectors pathogens that cause diseases such as dengue, yellow fever, chikungunya, and Zika. This global invasive has a distinct preference for biting human beings versus other animals. Ae. aegypti is native to Africa, where some populations do not show the marked human preference that characterizes populations of the globally invasive “domestic form.” Previous studies suggest that the populations which developed human preference did so by honing in on odor blends unique to human beings, especially long-chain aldehydes. Using a combination of single cell RNA data and glomerular size, the first ten odorant receptors of a partial atlas of the Ae. aegypti antennal were selected. Candidate genes were then compared with genes at loci previously linked to human preference. From these two approaches, genes were chosen for making transgenic knock-in strains via CRISPR for antennal lobe imaging. Receptors that map to the region of the glomerulus associated with human preference and also respond to long chain aldehydes will then be tested for human preference in behavioral assays. These transgenic mosquitoes will serve as the basis for further investigations into the underlying genomic and neuronal basis of human preference in Ae. aegypti.