Fig. 1. C. elegans form colonies at high density in the absence of bacteria.
a N2 C. elegans formed colonies on an NG plate upon consumption of bacteria. Inserts: blue: dispersed worms; orange: colonies. b, c Washed adult N2 C. elegans seeded at a low concentration (0.02 worms/mm2) (b) did not form stable colonies on an agarose plate (Inserts show individual worms), but those seeded at high density (0.18 worms/mm2) (c) did. d, f Dauer-stage worms were seeded on agarose pads (d) or adults on agarose plates (f) at various densities and the systems were allowed to equilibrate for 30 min. Colonies appeared on pads with higher seeding density (arrows) but not with lower. e, g Measured densities of dispersed dauer worms (e) or adult worms (g) as a function of seeding density. Worms were seeded at various densities on agarose plates and the systems were allowed to equilibrate for 30 min. Plates where colonies formed are indicated with filled circles, and plates with no colonies with open circles. Data are from three independent experiments for either dauer (e) or adult worms (g).