The effect of <i>MRK1</i> deletion or depletion of internally initiated <i>MRK1</i> on sporulation and spore wall integrity.

<p>Strains of indicated genotypes were sporulated in liquid (WT-AN120; <i>chs3</i>Δ-AN262; <i>mrk1</i>Δ-ySZ102; <i>mck1</i>Δ-ySZ23; <i>mrk1</i>Δ <i>mck1</i>Δ-ySZ46; <i>rim11-md</i>-ySZ39; <i>mrk1</i>Δ <i>rim11-md</i>-ySZ135; <i>mrk1-mMSE rim11-md</i>-ySZ98; <i>rim11-md</i>+vector-ySZ317; <i>mrk1</i>Δ <i>rim11-md</i>+vector-ySZ318; <i>mrk1</i>Δ <i>rim11-md</i>+<i>sMRK1</i>-ySZ315). Cells were allowed to sporulate either at 30°C for >48 h, or at 16°C for >96 h. <b>(A) Sporulation efficiency.</b> At least 300 cells of each strain were counted in each experiment. Bar plots represent the mean sporulation efficiency of at least 3 independent experiments. Error bars represent standard error of the mean. Statistical differences of strains in <i>rim11-md</i> background were examined by Student's t-test. Symbols denote statistical significance (* = p<0.05). <b>(B) Ascal type distribution.</b> At least 125 ascus of each strain were counted in each experiment. Bar plots represent the mean ascal type distribution of at least 3 independent experiments. <b>(C) Ether resistance of spores.</b> Each sporulation culture was diluted to a concentration of 10⁶ asci/ml, and 5-fold serial dilutions were spotted onto YPD plates. Left panels, plates unexposed to ether. Right panels, plates exposed to ether vapor for 30 minutes.