Xenopus Oocytes as a Heterologous Expression System

Oocytes of the South African clawed toad, Xenopus laevis , have proved a versatile and powerful heterologous expression system for eukaryotic genes (1 ). Xenopus oocytes were first used to express plant genetic material in 1979 (2 ), and in the past decade it has become increasingly evident that they are an appropriate and useful system to study plant proteins. As several comprehensive reviews of expression in oocytes have been published recently (1 , 3 –6 ), this chapter will concentrate specifically on those issues which are particularly relevant to the expression of plant genes with particular emphasis on the expression of plant transport proteins.