Fig 2: Macroscopic quorum sensing enables macroscopic colony to autonomously survive.a, Extracellular FGF4 concentrations, measured with ELISA, in N2B27 of a high-density population (seeded 8,620 cells per cm2) (Methods). Error bars are s.e.m.; n = 3 biological replicates. b, Cartoon: PD173074 inhibits FGFRs (Methods). Graphs: data from 46C cells after 6 days in N2B27 with RA. Red triangles: started differentiation with 2 µM of PD173074. Black and green points: differentiation without PD173074 but with the same DMSO concentration as for the red data points. Error bars are s.e.m.; n = 3 biological replicates. c, Cartoon: how Yap1 and VP function. Data, after 6 days of differentiation, for a high-density population (seeded 5,172 cells per cm2) and a low-density population that was rescued with supernatant from 2-day-old high-density population (seeded 862 cells per cm2). Error bars are s.e.m. All conditions show n biological replicates as follows. Black: n = 16 for high density, n = 3 for low density. Red: n = 3 for both densities. Last column: n = 4 for both densities. d, Normalized amount of phosphorylated Yap1 (inactive Yap1) measured with ELISA for 46C cells in N2B27 with RA (Methods). Densities are defined in c. Gray: low-density population rescued after 2 days by supernatant from 2-day-old high-density population. Green: low-density population starting with 200 ng ml-1 of FGF4. Error bars are s.e.m.; n = 3 biological replicates. e, Usual cell seeding protocol for a low-density population (~5,000 cells per ml). Representative images from n = 3 biological replicates. Scale bars, 200 µm. f, Seeding cells as one liquid droplet. Representative images from n = 3 biological replicates. Both images are from stitching together multiple fields of view. Each field is 1.40 mm × 0.99 mm. White outline: visual guide. Scale bars, 2 mm. g, Macroscopic colonies after 10 days in N2B27 with RA. Representative images from n = 3 biological replicates. Left column: pictures from a phone camera (estimated scale bar, 2 cm). Top row: 10-cm-diameter dish (left) and a zoomed-in view of a macroscopic colony (right). Bottom row: 6-cm-diameter dish (left) and a zoomed-in microscope image: stitched together multiple fields of view.