Fig. 1. cnox-2 expression in the interstitial cell, mechanoreceptor and neuronal cell lineages. (A) cnox-2 expression in adult polyps of Hv. (B) Apical cnox-2⁺ pairs of dividing i-cells (arrow) and differentiated neurons. (C) Gastric cnox-2⁺ i-cells, either single or twins, and clusters of synchronously dividing nematoblasts. (D) cnox-2⁺ apical multipolar neurons (arrows) detected with anti-ß-tubulin staining (see Fig. S1 in the supplementary material). (E) cnox-2⁺ gastric cells that correspond to i-cells and nematoblast clusters but not neurons (arrowheads). D and E are confocal views. (F) Distribution of the i-cells and nematoblast clusters among the gastric cnox-2⁺ cells during starvation counted on ten hydra. (G-J) cnox-2 expression in the sf-1 mutant maintained at permissive (18°C, G,H) or restrictive (26°C, I,J) temperatures for 2 days. (K-N) Absence of cnox-2 expression during oogenesis (K,L, arrows) and spermatognesis (M,N, arrowheads). Scale bars: 400 µm in A,G,I,K,M; 100 µm in H,J,L,N; 20 µm in B,C; 10 µm in D,E. ic, i-cell; nb, nematoblast; ne, neuron; oo, oocyte; te, testes.