Functional assay of mammalian and insect olfactory receptors using xenopus oocytes

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 dif fi cult. These efforts arefurther complicated by dif fi culties in expressingORs in many standard expression systems. Xenopus laevis oocytes offer a versatileexpression platform forthe de-orphaning and functional characterization of ORs. Two-electrode voltage clamp electrophysiology is acommon and relatively straightforward approach to the functional assay of receptors expressed inXenopus oocytes, and this techniquehas been discussed extensively in the literature. However, laboratoriesthat 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. © Springer Science+Business Media, LLC 2013.