Figure 4

Confocal images of Fz-GFP and actin in aristae. All panels are projections from confocal stacks and are from Alexa 568 phalloidin stained arm-fz-GFP containing pupae. GFP is in green and phalloidin in red. The four panels on the right show aristae at progressively more advanced developmental stages. All of these animals are wild type except for carrying the arm-fz-GFP transgene. Note that Fz accumulated preferentially on the distal sides of cells (arrows). In the oldest arista (40 hr) the more distal central core cells have become far more elongated and in these it is difficult to assess if Fz is still present preferentially along the distal edge. Even in the proximal cells in this arista the preferential distal accumulation appears less prominent. Particularly in 31 and 36 hr aristae the actin-stained laterals are located in the distal part of the cell, but do not directly overlap the region where Fz-GFP has accumulated. The distal accumulation of Fz-GFP is also seen in cells that do not form laterals. In the arm-fz-GFP ; in arista we still see the preferential accumulation of Fz-GFP at the distal borders of cells. Note however that lateral formation is not restricted to the distal part of the cell and that one cell in this image (see arrowhead) is forming two closely juxtaposed laterals. Once again the arrow points to small non-lateral producing cells where Fz-GFP accumulated along the distal/proximal boundary of the cells. In the fy; arm-fz-GFP the situation is similar to the arm-fz-GFP ; in arista. In the dsh¹; arm-fz-GFP arista the preferential distal localization of Fz-GFP is lost. Actin is accumulating at a central location in the lateral producing cells. Note the formation of laterals is no longer restricted to the distal region of the cells in the in, fy or dsh mutants (marked by arrowheads). We also find that Dsh-GFP accumulates preferentially at the distal side of cells. The bottom two panels are higher magnification images of Fz-GFP in wing and arista cells. Note the preferential accumulation of Fz-GFP at the distal edges and that it is not uniform. Both images are from cells that where hairs or laterals are partly developed. The arista image is from the 36 hr arista panel in this figure.