The mosquito endoscopy, or how do mosquitoes orient proboscis in the human skin: connecting mosquito saliva, cuticle of the mouth and nervou

The mosquito Aedes albopictus is an invasive species that has colonised the south of Europe and it's expanding its range toward the North. It is a vector of multiple human and animal pathogens and its bites cause itching bumps, thanks to the saliva that is injected in the skin during the acquisition of a blood meal. The saliva helps mosquito to find a vessel in the skin and we have previously demonstrated that one protein, named LIPS-2, binds the tip of the labrum, which is one of the component of the mosquito proboscis that are inserted in the skin. This interaction is mediated by a cuticular protein, Cp19, and causes a modification of the cuticle of the labral ridges; concomitantly, this interaction induces the probing movements of the mouth. But how a protein-protein interaction can mediate a behavioural change? We believe that this interaction changes the conformation of the chitin fibrils and that this change can be sensed by nerve dendrites.