Figure 3. SYS-1, BAR-1, and VANG-1 Expression in VPC Progeny. (A) Subcellular localization of qIs95, a VNS::SYS-1 translational fusion. qIs95 is expressed at very low levels. To characterize the localization, we captured a still fluorescence image using a long exposure time (8 s) and then applied the 'Auto Contrast' function of Adobe Photoshop CS2. The resulting localization pattern was readily classifiable by eye into one of the three categories: SYS-1 was enriched in the anterior P7.p daughter nucleus (P7.pa > P7.pp), SYS-1 was present at similar levels in both P7.p daughter nuclei (P7.pa = P7.pp), or SYS-1 was enriched in the posterior P7.p daughter nucleus (P7.pa < P7.pp). A representative image is shown above each category, and the number of worms in each category is listed. The VNS::SYS-1 localization pattern in P5.p daughters was unaffected in all of the genotypes examined, with the exception of symmetric distribution in a single
lin-17(lf);
egl-20(lf) double-mutant worm and in two
lin-17(lf);
egl-20(lf);
lin-18(lf) triple mutants.(B) Nomarski (above) and fluorescence (below) images show VNS::SYS-1 localization during cell division. For the wild-type and
lin-17(lf) mutants, the images on the right were taken 5 min after the images on the left. The two spots seen in the fluorescent images on the left are putative centrosomes. Arrowheads point to anterior daughter nuclei, and arrows point to posterior daughter nuclei.(C) BAR-1::GFP translation fusion; display is the same as in (A).(D) A
bar-1::GFP reporter that contains 5.1 kb of the
bar-1 5' regulatory region driving expression of nucleolus/nuclear-localized GFP. This promoter region is the same as in (C) (Eisenmann et al., 1998).(E)
vang-1::YFP reporter is expressed in the VPC progeny (arrowheads). The bright
vang-1::YFP-expressing cell (arrow) is a ventral cord neuron.