John Castillo

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Bio

I was a biological sciences major at Florida International University. I enjoy the arts, food, and exercising. I am interested in a career in molecular genetics. I am currently a Ph.D. student in the DeGennaro lab.

Project

The primary objective of this project is to understand the mechanism by which Aedes aegypti sense lactic acid, a major component of human sweat. IRs are a family of odor-gated ion channels that are employed by insects to detect chemicals in their environment. IR’s are members of the Ionotropic glutamate receptor (iGluRs) family of ligand-gated ion channels that possess divergent ligand binding domains that sense odors. IRs usually respond to acids and amines, while ORs are broadly tuned to aromatics, alcohols and esters. Studying the IR8a pathway can allow us to understand a crucial sensory cue that allows mosquitoes to detect humans. Our previous work has shown that mosquitoes lacking the Ir8a receptor have reduced attraction to lactic acid as well as other human odor components. Targeting receptors associated with Ir8a we can help uncover the specific protein-protein interactions responsible for eliciting a behavioral response towards human odor. The genetic interactions involved in human host detection dependent on mosquito IR’s have only recently prematurely been explored. Assessing the Ae. aegypti odor specific IRs function through genetic manipulation can help us understand mosquito human host preference. Due to the ability to genetically modify animals using CRISPR/Cas9, Ae. aegypti has become highly accessible to genetic studies. In the DeGennaro lab using this technique we have created multiple null mutant alleles that we use to study different mosquito behaviors. More specifically we have shown that removal of Ir8a from the Ae. aegypti genome reduces female mosquito attraction to humans. Understanding the genes involved in sensing major human odor components can allow us to develop receptor specific attractants and repellents that can be used to control mosquito host seeking behavior. The mosquito is the deadliest animal on the planet and by designing mosquito repellents that reduce the ability for Ae. aegypti to host seek we can reduce the spread of endemic viruses such as Zika, dengue, and chikungunya.

The over arching objective of this project has two parts: (i) identify the receptor responsible for mosquito attraction to lactic acid; and (ii) establish a list of odor-specific IRs that are IR8a-dependent and assess their response to different chemicals in Xenopus laevis oocytes.

 

Email: jcast341@fiu.edu