Fig. 4. daf-5 controls cell cycle arrest in the seam cells of dauer larvae by regulating expression of a cyclin kinase inhibitor. (A,B) rnr-1::GFP expression in N2 and daf-5; daf-1 double mutants. A corresponding Nomarski image can be found in Fig. S2 at http://dev.biologists.org/supplemental. White arrowheads show seam cells that express rnr-1::GFP in N2 and in daf-5; daf-1, respectively, at early L3 stage. (C,D) cki-1::GFP expression in daf-1 and daf-5; daf-1 mutants. A corresponding Nomarski image can be found in Fig. S2 at http://dev.biologists.org/supplemental. (C) cki-1 is expressed along the seam cells in all daf-1 dauer larvae with an average of 16 green cells. White arrowheads (E) show seam cell nuclei. (D) cki-1 is expressed in a subset of daf-5; daf-1 mutants in early L3. Two daf-5; daf-1 animals are shown. The top animal is representative of the 37% of animals of this genotype that had no GFP in the seam at all. The bottom animal is representative of the 34% that expressed GFP faintly in many seam cells (between five and ten). White arrows point to the seam cells that do not express cki-1::GFP in the nuclei. Scale bars: 1 µm.