Fig. 2. Quantitative summary of PAL-1 and MEX-3 localization data. (A) PAL-1 localization patterns in four-cell embryos. Wild-type, par-1, par-4 or par-3 hermaphrodites, as indicated below the graphs, were injected with dsRNA, as indicated on the left. PAL-1 was scored as being present in none of the nuclei, all of the nuclei or patterned (see key). Patterned embryos express PAL-1 only in posterior blastomeres (see Fig. 1A), with the exception of par-3(it71) and par-3(RNAi) embryos, which express PAL-1 in two of four blastomeres but do not have an obvious polarity. Data for uninjected par-4(it57ts) and uninjected par-3(it71) embryos are taken from Bowerman et al. (Bowerman et al., 1997). (B) PAL-1 localization in embryos at different stages. Genotypes are indicated to the left and embryo stage is indicated below the graphs. In all cases in which PAL-1 was scored as patterned, PAL-1 was expressed only in posterior blastomeres (see Fig. 3B-D). (C) MEX-3 localization in wild-type and mutant embryos at different stages. Genotypes are indicated to the left and embryo stage is indicated below the graphs. In all two- and four-cell embryos in which MEX-3 was scored as patterned, MEX-3 was clearly brighter in the anterior blastomere(s) than in the posterior blastomere(s), as in the wild-type four-cell embryo in Fig. 5A2. In two- and four-cell embryos that were scored as ‘all’, MEX-3 was detected in all blastomeres with no clear asymmetries in signal intensity between anterior and posterior. Eight-cell and 14- to 18-cell embryos were not scored for MEX-3 patterning and were scored only for the presence or absence of MEX-3 in the majority of blastomeres. In this way, wild-type embryos expressing MEX-3 in P₂ blastomere descendants (see Fig. 5A4) were scored as ‘none’ because they do not express MEX-3 in the majority of blastomeres. The data presented in these graphs reflect only the presence or absence of MEX-3 and do not reflect the intensity of MEX-3 signal, with the exception of clearly ‘patterned’ embryos, as described above. The total number of embryos scored is indicated above each bar in each case.