Fig. 5. Ssm4p is expressed during fission yeast mating and localises to microtubules. (A) cyr1 sxa2 ssm4GFP cells were induced for 6 hours with pheromone, cells were then fixed in methanol and immunostained with anti-tubulin (MT) and anti-Sad1 antibodies. Arrows indicate the SPB and arrowheads the point where microtubule plus ends contact the cell surface. (B) cyr1 sxa2 ssm4GFP cells were induced for 6 hours with pheromone, treated with MBC and imaged on a fluorescent microscope before and after the treatment. (C) cyr1 sxa2 ssm4GFP cells were induced with pheromone for 6 hours, placed on a slide and filmed with a fluorescence microscope. Frames are 8-10 seconds apart. White arrows indicate the microtubule tips and yellow arrowheads the fluorescent dot at the SPB, which can be identified as a point where more than one microtubule originates. The microtubular tip is anchored in a fixed position in a, c and d and the SPB is moving towards it as the microtubule depolymerises. In b, the SPB is not moving and the microtubule is depolymerising back towards it. Bars, 3 µm. (D) Fluorescence at the tip of microtubules in C (marked by the white arrow) was measured with NIH image for each frame and plotted.