Biochemical Genetics

, Volume 18, Issue 11, pp 1109–1130

Genetic and functional analysis of tryptophan transport in Malpighian tubules of Drosophila

  • David T. Sullivan
  • L. Anne Bell
  • Duncan R. Paton
  • Marie C. Sullivan
Article

DOI: 10.1007/BF00484342

Cite this article as:
Sullivan, D.T., Bell, L.A., Paton, D.R. et al. Biochem Genet (1980) 18: 1109. doi:10.1007/BF00484342

Abstract

Dissected Malpighian tubules from wild type and the eye color mutant white of Drosophila were compared with respect to their abilities to transport tryptophan and kynurenine into tubule cells. It was determined that mutation at white greatly impairs the ability of Malpighian tubule cells to take up tryptophan. Functional studies on the extracellular spaces and ultrastructural observations indicated no differences in these respects between wild type and white tubules. It is consistent with several observations that much of the tryptophan associated with white exists in the intercellular spaces. Furthermore, the uptake of tryptophan by the w+ system of wild type tubules is inhibited by the analogue 5-methyl-tryptophan. However, the incorporation of radioactive tryptophan into protein in tubule cells from wild type and white occurs at the same rates and is not affected by 5-methyl-tryptophan. Therefore, it is apparent that Malpighian tubules have a transport system that enables entry of tryptophan into a cellular pool and that this cellular pool is initially independent of the tryptophan pool used for protein synthesis. The mutant white lacks this transport system. From these studies and others it appears that compartmentalization of cellular pools may be brought about via the utilization of specific membrane transport systems.

Key words

TryptophankynureninewhiteDrosophila melanogasteramino acid transportMalpighian tubules

Copyright information

© Plenum Publishing Corporation 1980

Authors and Affiliations

  • David T. Sullivan
    • 1
  • L. Anne Bell
    • 1
  • Duncan R. Paton
    • 1
  • Marie C. Sullivan
    • 1
  1. 1.Department of BiologySyracuse UniversitySyracuse