PLK-1 and CDC-25.1 asymmetries depend on PAR and MEX-5/MEX-6 proteins. PLK-1 and CDC-25.1 in two-cell embryos (left); and DNA (DAPI, blue) and tubulin (red; right). Cytoplasmic PLK-1 and nuclear CDC-25.1 show symmetric distributions in each mutant. par-3 mutant and mex-5; mex-6 double RNAi embryos show low cytoplasmic PLK-1 and nuclear CDC-25.1 levels and par-1, -2, and -4 embryos show high cytoplasmic PLK-1 and nuclear CDC-25.1 levels. Quantification is shown in Fig. 5. Bar, 10 μm.