(a) Growth of transformants on glucose (Left) and galactose (Right) medium. On each plate, the SK1006 (ste4) derivatives are on the left and the SK1007 (ste4 gpa1) derivatives are on the right. Plasmids are, from top to bottom: pGT5 (vector), pG1501 (GPA1), pGT-STE4–1 (STE4), pSTE4-GPA1-a (STE4-GPA1-a), pSTE4-GPA1-b (STE4-GPA1-b). (b) Mating of transformants on glucose (Left) and galactose (Right) medium. Cells were patched onto a lawn of tester strain NKY102 (MATα ade8) on an SD-glucose or SD-galactose plate lacking uracil (10), and incubated at 30°C. The mixture was replicated to an SD-glucose plate with no supplements and incubated at 30°C, to select for diploids.