Mutation affecting taste perception in Drosophila melanogaster

Abstract

ANALYSIS of mutant organisms can elucidate by contrast the development of the normal phenotype and this approach can be used to break down behavioural characteristics into their embryological and physiological components. Taste in insects is a characteristic suitable for such a study. Genetic analysis of taste in Drosophila melanogaster can complement the electrophysiological and anatomical information on taste organs of flies obtained mainly from Calliphora and Phormia. The taste organs of flies are located predominantly on the labella at the tip of the proboscis, and on the tarsi. On each half labellum of Drosophila there are 36–42 taste bristles on the surface and some 25 taste pegs between the pseudotracheae. All but five or six bristles are penetrated by the dendrites of four chemoreceptors (the remaining ones having two dendrites), while there is only one chemoreceptor in each interpseudotracheal peg. Each taste organ is also provided with a mechano-receptor neurone (R. F., Bleiser-Avivi and J. A., in preparation). Of the four dendrites penetrating to the pore at the tip of the taste bristles in Phormia^1–3, one is a water sensor, one reacts to sugars and two react to salts^4–6.