Expression of G proteins in a Δric8 mutant. (A) Gα− and Gβ-protein levels. Samples containing 100 μg of protein from particulate fractions isolated from 16-hr submerged cultures were subjected to Western analysis using the GNA-1, GNA-2, and GNA-3 antibodies. The asterisk (*) denotes strains containing activated alleles of Gα genes. The double asterisk (**) indicates a background band observed in all GNA-3 Western blots. Strains used for analysis were wild type (FGSC 2489), Δric8 (R81a), Δric8 gna-1Q204L (R81*), Δric8 gna-2Q205L (R82*), and Δric8 gna-3Q208L (R83*). (B) Levels of Gα and Gβ transcripts. Samples containing 20 μg of total RNA isolated from 16-hr submerged cultures were subjected to Northern analysis using gene-specific probes. Strains used for analysis were wild type (FGSC 2489) and Δric8 (R81a).