Expression of theDrosophila melanogastermetallothionein genes in yeast

Abstract
The metallothionein system in Drosophila melanogaster is composed of two genes, Mto and Mn, that code for distinctly different proteins. In order to compare the properties of Mto and Mtn, we transformed yeast with several fusion plasmids. The Mto and Mtn cDNAs, when placed under the control of CUP1 or PGK promoters, can confer a copper‐resistance phenotype to copper‐hypersensitive cells. Both Mto and Mtn proteins can be characterized in extracts from transformed yeast cells.