Fig. 4. prx-5(RNAi)-arrested nematodes do not initiate postembryonic cell divisions. Strain LT483 contains an integrated 2X rnr-1 promoter driving expression of GFP. We injected this strain with dsRNA targeted to prx-5 and examined the progeny. The animal in A and B has just two faint cells that contain GFP. Eggs from this strain were hatched in the absence of food to induce a post-hatching starvation-arrest (C,D). prx-5(RNAi) animals and starvation-arrested animals of this strain have similar GFP expression patterns, and in addition they lack autofluorescence in their guts (A,C). (E) A young p_rnr-1GFP L1 animal in which divided nuclei are apparent by their more robust GFP signal. (F) An older p_rnr-1GFP L1 animal that contains numerous dividing nuclei. (G) A 4 day arrested prx-5(RNAi). This animal has been arrested for 4 days, and does not contain the numerous refractile structures found in a 4-day old starvation-arrested worm (H). Bars, 10 µm.