A Novel Role for Odorant Binding Proteins in Deactivation of Drosophila Olfactory Neurons
type: CreativeWork
description: In insects, odorant binding proteins are a large and diverse group of low molecular weight proteins secreted into the fluid bathing olfactory and gustatory dendrites. The best-characterized OBP, known as LUSH, is required in Drosophila melanogaster for the detection of physiological levels of the male-specific pheromone cVA. While LUSH acts as a sensitizing factor for pheromone detection, the role of other OBPs encoded in the Drosophila genome is largely unknown. In an effort to characterize members of this family, I used CRISPR-Cas9 to generate and characterize a deletion of two genes encoding the homologous OBPs OS-E and OS-F. These OBPs are nearly 70% identical and their expression is restricted to a small set of antennal chemosensory sensilla. Electrophysiological analysis of the olfactory neurons within these sensilla revealed no major difference in odorant sensitivity or specificity in the mutants but did reveal a striking deactivation defect to a subset of odorants. Surprisingly, other odorants detected by the same receptor are differentially affected by the absence of OS-E and OS-F, revealing an odorant-specific role for these OBPs in deactivation kinetics. Activation kinetics remain normal for the affected odorants in mutants. Genomic rescue experiments revealed that OS-E and OS-F are also functionally redundant, as either OBP is sufficient to revert the mutant phenotype. My findings reveal a new role for OBPs in deactivation of olfactory neurons and expand our understanding of the range of OBP functions.
abstract: In insects, odorant binding proteins are a large and diverse group of low molecular weight proteins secreted into the fluid bathing olfactory and gustatory dendrites. The best-characterized OBP, known as LUSH, is required in Drosophila melanogaster for the detection of physiological levels of the male-specific pheromone cVA. While LUSH acts as a sensitizing factor for pheromone detection, the role of other OBPs encoded in the Drosophila genome is largely unknown. In an effort to characterize members of this family, I used CRISPR-Cas9 to generate and characterize a deletion of two genes encoding the homologous OBPs OS-E and OS-F. These OBPs are nearly 70% identical and their expression is restricted to a small set of antennal chemosensory sensilla. Electrophysiological analysis of the olfactory neurons within these sensilla revealed no major difference in odorant sensitivity or specificity in the mutants but did reveal a striking deactivation defect to a subset of odorants. Surprisingly, other odorants detected by the same receptor are differentially affected by the absence of OS-E and OS-F, revealing an odorant-specific role for these OBPs in deactivation kinetics. Activation kinetics remain normal for the affected odorants in mutants. Genomic rescue experiments revealed that OS-E and OS-F are also functionally redundant, as either OBP is sufficient to revert the mutant phenotype. My findings reveal a new role for OBPs in deactivation of olfactory neurons and expand our understanding of the range of OBP functions.
author: Scheuermann, Elizabeth Anne
language: en
keywords: Carrier Proteins, Drosophila Proteins, Loss of Function Mutation, Phenotype
date published: 2021-09-17T17:59:48Z
date modified: 2026-07-24T05:52:31Z
provider: University of Texas Southwestern Medical Center
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Texas Southwestern Medical Center

PropertyValue
property ID: Handle
value: https://hdl.handle.net/2152.5/9626