Functional assays for insect olfactory receptors in Xenopus oocytes.

Reconstitution of olfactory or pheromone receptors in heterologous expression systems greatly facilitates the functional analysis of these receptors. Xenopus laevis oocytes can be used to efficiently express insect olfactory or pheromone receptors. In this chapter, we describe how to use Xenopus laevis oocytes for functional assays of insect olfactory receptors. The procedure can be subdivided into the four following steps: (1) in vitro complementary RNA (cRNA) synthesis, (2) isolation of oocytes from female Xenopus laevis, (3) cRNA microinjection into oocytes, and (4) two-electrode voltage-clamp recording. This system can be used to identify odor or pheromone ligands and to analyze structure-function relationships involving receptor proteins of interest.