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Updated: May 12, 2026
Functional Evaluation of Olfactory Pathways in Living Xenopus Tadpoles
Published on: December 11, 2018
Functional assay of mammalian and insect olfactory receptors using Xenopus oocytes
Charles W Luetje1, Andrew S Nichols, Ana Castro
1Department of Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami, Miami, FL, USA.
Abstract:
The large number of olfactory receptors (ORs) expressed by various mammalian and insect species, as well as the large number of potential odorant ligands, has made the pairing of odorants with receptors -(de-orphaning) exceedingly difficult. These efforts are further complicated by difficulties in expressing ORs in many standard expression systems. Xenopus laevis oocytes offer a versatile expression platform for the de-orphaning and functional characterization of ORs. Two-electrode voltage clamp electrophysiology is a common and relatively straightforward approach to the functional assay of receptors expressed in Xenopus oocytes, and this technique has been discussed extensively in the literature. However, laboratories that are new to the use of Xenopus oocytes are often stymied by some of the peculiarities of the Xenopus oocyte expression system. We discuss some of the key methodological issues in Xenopus care, oocyte -isolation and receptor expression, with a focus on using this expression system to study the ORs of mammals and insects.
Insights
De-orphaning olfactory receptors (ORs) is challenging due to their vast numbers. Xenopus laevis oocytes provide a versatile system for OR functional characterization, overcoming expression difficulties.
Area of Science:
- Olfactory receptor research
- Neuroscience
- Xenopus oocyte expression systems
Background:
- The vast number of olfactory receptors (ORs) and odorant ligands presents a significant challenge for identifying specific odorant-receptor interactions (de-orphaning).
- Standard expression systems often encounter difficulties when expressing ORs, hindering functional studies.
Purpose of the Study:
- To highlight Xenopus laevis oocytes as a powerful and versatile platform for the de-orphaning and functional characterization of olfactory receptors.
- To address common methodological challenges faced by new laboratories utilizing the Xenopus oocyte system for OR research.
Main Methods:
- Utilizing Xenopus laevis oocytes as an expression system for olfactory receptors.
- Employing two-electrode voltage clamp electrophysiology for functional assays of expressed ORs.
- Discussing key methodological considerations in Xenopus care, oocyte isolation, and receptor expression.
Main Results:
- Xenopus oocytes facilitate the expression and functional characterization of olfactory receptors, aiding in the de-orphaning process.
- The study provides practical insights into overcoming specific challenges associated with the Xenopus oocyte expression system.
Conclusions:
- Xenopus laevis oocytes offer a robust and adaptable system for studying olfactory receptor function, particularly for de-orphaning efforts.
- Addressing methodological peculiarities in Xenopus oocyte handling and receptor expression is crucial for successful olfactory research in both mammalian and insect systems.
