Fig. 5. gpc-1, adp-1 and osm-9 mutant animals are defective in adaptation to salts. Wild-type, gpc-1, gpc-1; gpc-1R, gpc-1XS, adp-1 and osm-9(n1603) animals were tested for chemotaxis to 25 mM NaAc (A), NaCl (B) and NH₄Cl (C), after pre-exposure to a low-salt buffer (non-adapted; black bars, na), 100 mM NaAc (A), NaCl (B), or NH₄Cl (C) (adapted; open bars, a). The genotypes are indicated below the assays. The chemotaxis index was determined 10 min after the animals were placed on the chemotaxis plates. Asterisks indicate a statistically significant difference between wild-type and mutant adapted animals (p <0.001).