Figure 2.  Analysis of ASH1-particle movement in yeast.  

Yeast that expresses both the ASH1 (asymmetric synthesis of HO endonuclease) reporter gene, which contains MS2 stem–loops, and the green fluorescent protein (GFP)–MS2 protein were observed using epifluorescence and bright-field microscopy. Movement of the GFP–MS2-coated ASH1 mRNA particle was recorded and followed over time. Images are presented at indicated intervals.
a–f. Movement of the particle from the mother cell to the bud (total distance: 23 µm in 128 s).
g. The diagram shows the total path of the particle movement (43 µm in 240 s). Intervals of 30 s each are represented by different colours and images a–f are indicated by white dots on the travel line. The particle spends 180 out of 240 s in the bud and ~60 s localized at or near the bud tip.
h. A yeast strain that contains a deletion of she1 (a microfilament motor that is required for the localization of ASH1 to the bud tip) and was analysed by the same approach showed significantly less net displacement and stayed within the mother cell, never localizing to the bud tip. Bar, 2 µm.

Reproduced with permission from Bertrand E, et al, 1998.