FIG. 2.

Glutamate auxotrophy of rtg mutant cells coincides with RTG-dependent gene expression. Wild-type (WT) PSY142 [rho⁺] and [rho⁰] cells and rtg1Δ, rtg2Δ or rtg3Δ mutant derivatives of those strains were streaked on YNBR or YNBD medium with or without 0.02% glutamate. (A) YNBR plus glutamate; (B) YNBR alone; (C) YNBD plus glutamate; (D) YNBD. Only the [rho⁰] mutant derivatives are glutamate auxotrophs in derepressed cells, whereas both [rho⁺] and [rho⁰] mutant derivatives are glutamate auxotrophs in glucose-repressed cells.