If you often get bitten by mosquitoes, you may be wondering how they always seem to find and feed off of us!
Well, it turns out that their very olfactory system is wired in such a way that there is a backup meant to detect human scents.
More precisely, they can smell CO2 or sweat coming off human beings thanks to the chemoreceptors found in their maxillary palp.
A new Boston University and Rockefeller University joint study explains in more detail why mosquitoes are so good at hunting us down even when scientists genetically disable human specific chemoreceptors.
The research team concluded that one species of mosquitoes in particular, Aedes aegypti, features a totally different way of organizing its olfactory system when compared to most other animals.
The researchers used CRISPR as a gene editing tool and created mosquitos whose olfactory neurons glow under the microscope by expressing fluorescent proteins whenever certain smells are close by.
This process allowed them to really see just how different smells can stimulate their olfactory system.
They learned that this species of mosquito connects a number of sensory receptors to the one neuron which overturns a basic principle of olfactory science, which suggests that each neuron has only one chemoreceptor linked to it.
Meg Younger, the senior author of the study and a neuroscientist at Boston University, admits that “This is shockingly weird. It’s not what we expected. The central dogma in olfaction is that sensory neurons, for us in our nose, each express one type of olfactory receptor.”
The study suggests that this species has a unique olfactory system that coexpresses a number of sensory receptors within individual neurons.
The expert goes on to assess that “The redundancy afforded by an olfactory system … may increase the robustness of the mosquito olfactory system and explain our long-standing inability to disrupt the detection of humans by mosquitoes.”
As you may or may not know, female mosquitos need to feed on human or animal blood in order to reproduce so the attraction to the smell of blood is strong.
Unfortunately, this unique talent for locating humans makes mosquitoes dangerous since they spread a number of scary viral diseases such as chikungunya, Zika, yellow fever, and dengue.
But Younger hopes this new information on how mosquitoes work can lead to the creation of new and more efficient products that can hide our scent or throw them off.