Lifeact-mEGFP in Plant Cells Figure 1. Maximal projections of confocal sections in moss and lily. (A) Maximal projection of a Physcomitrella caulonemal cell expressing Lifeact-mEGFP shows a prominent focal point at the apex along with cortical filaments in the subapical region. The insets show the bracketed area rotated 90u. (B) Maximal projection of a Physcomitrella chloronemal cell highlights the intense apical signal, which forms a patch with filaments emanating towards the rear of the cell. The insets show the bracketed area rotated 90u. For moss, bars represent 5 mm. (C) A maximal projection of Lifeact-mEGFP signal in lily highlights the cortical actin fringe. Inset shows the same cell rotated to exhibit cortical localization of actin signal at the tip. (D) A maximal projection of Lifeact-mEGFP signal in tobacco shows the longitudinal actin filaments in the shank. Inset shows the same cell rotated 90u highlighting the cortical bias to the apical F-actin network. In both pollen species, the bar represents 10 mm. doi:10.1371/journal.pone.0005744.g001 Significantly, the probes co-localize throughout the cell, both in cells that have an apical F-actin network and those that lack apical labeling (compare top and bottom frames in Figure 2B). These data demonstrate that Lifeact-mEGFP is labeling the same F-actin as labeled by rhodamine phalloidin in fixed cells. They also suggest that MBS-EGS fixation alters the localization of the apical F-actin PLoS ONE | www.plosone.org 3 May 2009 | Volume 4 | Issue 5 | e5744