Figure 5. Thin section electron microscopy (EM) analysis shows polarized accumulation of secretory vesicles in the sso2M5 and sso2M7 strains.
A control sso1Δ SSO2 strain and sso1Δ sso2 mutants were grown in YPD medium at 25°C to an OD600 of 0.5, then 10 OD600 units of cells were collected and processed for EM analysis: (A) sso1Δ SSO2, (B) sso1Δ sso2M5, (C) sso1Δ sso2M6, and (D) sso1Δ sso2M7. Scale bar, 0.5 µm. sso2M5 and sso2M7 cells contain more secretory vesicles in the bud compared to SSO2 and sso2M6 cells. (E) Quantitation of secretory vesicles. The number of vesicles/cell was scored in 46 control cells, 49 sso2M5 cells, 51 sso2M6 cells, and 45 sso2M7 cells. (F) Measurement of vesicle size. The measurement was analyzed using ImageJ; 23–91 vesicles were measured.