Fig. 6. The mdy2 mutant shows defects in microtubule orientation and mislocalizes Kar9 in response to pheromone. (A) Cells containing pMET-GFP-TUB1 (pGX388) plasmids were grown to log phase and induced in methionine-free medium for 2 hours; then 5 µM -factor was added for another 3 hours. After brief fixation, wild-type (WT; HZH638) and mdy2 (HZH386) cells were scored for GFP-Tub1 localization (n>100). Cells were scored as having (from top to bottom): a single bundle of cytoplasmic tubules directed to the shmoo tip, a single bundle of cytoplasmic microtubules going to the shmoo tip plus other bundles oriented away from the shmoo tip, no cytoplasmic microtubules going to the shmoo tip and a spray of microtubules localized on the opposite side to the shmoo. (B) Cells containing pGAL-GFP-KAR9 were grown in 3% raffinose and 1% galactose for 2 hours, and then pheromone was added for another 3 hours. After brief fixation, wild-type (WT; W303-1A), mdy2 cells were scored for GFP-Kar9 localization (n>250). Cells were scored as having (from top to bottom): a single cortical dot, a line of localization, multiple dots forming a cap near the shmoo tip, or dispersed dots elsewhere in the cell body, possibly on misoriented microtubules.