Employing High Probability Gene Choice Elements to Understand Singular Odorant Receptor Expression
type: CreativeWork
description: The ability to detect odorous chemicals in the environment is the oldest of the senses necessary for survival, from escaping danger, finding mates, to locating food. It is said that humans can identify and discriminate up to a trillion different odor mixtures. For chemoreception to have such a high discriminatory power, would require a diverse population of cells dedicated for odor detection. These detector cells are the olfactory sensory neurons (OSNs), which express odorant receptors (ORs) that bind to chemical odors in the environment. In order to increase specificity and sensitivity, an essential property in olfaction is for each OSN to express an OR in a monogenic and monoallelic fashion. Out of a large repertoire of OR genes, it is curious how a single OSN will choose not just one OR gene but only one allele of that gene to be expressed. The mechanisms establishing how one OR is expressed per OSN, referred to as singular gene choice, remain to be fully resolved. Current models stipulate OR co-expression is possible, but limited to immature OSNs due to competition for transcription and negative feedback mechanisms that ensure only one OR is expressed in a mature cell. This work aims to understand how singular gene choice may be regulated by employing a unique platform that can test whether singularity can be broken. We make use of a high probability (HP) gene choice element to test whether it is possible to express two ORs in a single OSN so we can directly test both the competition for transcription and negative feedback models. We have previously shown that this element results in a dramatic increase in the population of OSNs expressing a defined cloned OR coding sequence (CDS) in transgenic mice, while seemingly using the same endogenous expression and choice mechanism for wild type ORs. These HP transgenes range in representation in the main olfactory epithelium (MOE); from ~2% to about ~50% of OSNs expressing the defined OR. We crossed several HP transgene…
abstract: The ability to detect odorous chemicals in the environment is the oldest of the senses necessary for survival, from escaping danger, finding mates, to locating food. It is said that humans can identify and discriminate up to a trillion different odor mixtures. For chemoreception to have such a high discriminatory power, would require a diverse population of cells dedicated for odor detection. These detector cells are the olfactory sensory neurons (OSNs), which express odorant receptors (ORs) that bind to chemical odors in the environment. In order to increase specificity and sensitivity, an essential property in olfaction is for each OSN to express an OR in a monogenic and monoallelic fashion. Out of a large repertoire of OR genes, it is curious how a single OSN will choose not just one OR gene but only one allele of that gene to be expressed. The mechanisms establishing how one OR is expressed per OSN, referred to as singular gene choice, remain to be fully resolved. Current models stipulate OR co-expression is possible, but limited to immature OSNs due to competition for transcription and negative feedback mechanisms that ensure only one OR is expressed in a mature cell. This work aims to understand how singular gene choice may be regulated by employing a unique platform that can test whether singularity can be broken. We make use of a high probability (HP) gene choice element to test whether it is possible to express two ORs in a single OSN so we can directly test both the competition for transcription and negative feedback models. We have previously shown that this element results in a dramatic increase in the population of OSNs expressing a defined cloned OR coding sequence (CDS) in transgenic mice, while seemingly using the same endogenous expression and choice mechanism for wild type ORs. These HP transgenes range in representation in the main olfactory epithelium (MOE); from ~2% to about ~50% of OSNs expressing the defined OR. We crossed several HP transgene…
author: Mina, Raena
keywords: Biology, Molecular and Cellular Neuroscience, Molecular Genetics, Gene regulation, olfaction, odorant receptors
date published: 2020-09-01T07:00:00Z
date modified: 2026-07-24T01:58:57Z
provider: City University of New York - Graduate Center
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The Graduate School and University Center of The City University of New York