EXPRESSION OF TASTE RECEPTION RESPONSE OF FLESHFLY IN XENOPUS OOCYTES

FUNCTIONAL expression of the gustatory sensitivity to amino acids and sugars was investigated in Xenopus oocytes injected with poly(A+) RNA extracted from fleshfly labellar taste organs. The current induced by the application of amino acids and sugars that stimulate fleshfly suga r receptor cells was recorded under voltage clamp conditions. L-Phenyl alanine and L-valine induced a large transient inward current in poly( A+) RNA-injected oocytes but only small responses in uninjected contro l oocytes. Glucose and fructose also produced inward currents in the R NA-injected oocytes. N-methylated compounds or D-isomers of these amin o acids induced either no response or a much smaller response than L-a mino acids as they did in the fleshfly sugar receptor cells. The oocyt e expression system is a useful tool for characterizing the taste tran sduction mechanism.