Regulated gene expression in yeast and method of use

The present invention relates to methods and compositions for regulated expression of specific genes in . The invention can be used to identify and clone genes of interest and to identify antifungal agents using high-throughput screening techniques. The invention also relates to the use of the strains of the invention in the isolation and analysis of antifungal agents. The invention provides novel yeast cells comprising genes whose expression can be modulated by growth in the presence or absence of metal ions, methods for making such yeast cells, and methods of using such yeast cells for determining the requirement for expression of particular genes for the growth or viability of the yeast cells. The invention also provides methods of using such yeast cells in the isolation, screening and analysis of candidate antifungal compounds.