Recovering a Chemotopic Feature Space from a Group of Fruit Fly Antenna Chemosensors

Abstract

The ensemble of odorant receptors on the antenna of the fruit fly Drosophila melanogaster acts as an encoder for chemical molecules. Chemically similar odorants elicit activity in similar subsets of the receptors, spanning a so-called chemotopic feature space that enables chemical similarity search. A compound signal of receptor activity can be read out by calcium imaging of the antenna, yet without revealing corresponding receptors on different antennae. Employing Canonical Correlation Analysis (CCA) for multiple sets, we show that a consensus feature space can nevertheless be recovered from a group of variable antenna sensors that all respond to a common sequence of odorants. In the chemotopic consensus feature space, properties of novel odorants can be inferred, demonstrating how fruit fly antenna chemosensors may be employed as an alternative to electronic noses.