FIGURE 1.

mi264 embryos exhibit weak touch-evoked coiling. A–H, tactile stimulation induced vigorous coiling in a wild-type embryo (26 hpf). The head and yolk of the embryo was embedded in an agarose gel, leaving the trunk and tail free to move. Superimposed (A) and individual movie frames (B–H) show vigorous coiling behavior in the wild-type embryo. I–P, tactile stimulation induced weak coiling in a mi264 embryo. Superimposed (I) and single frames (J–P) reveal weak coiling in the mutant embryo. Q, schematic of quantitative analysis of the amplitude of the coils as measured by the caudal trunk angle. R and S, superimposition of movie frames showing that the displacement of the trunk and tail in a wild-type embryo (R) and a mi264 mutant (S) during burst swimming are comparable at 48 hpf. T, histograms showing that the maximum amplitude of touch-induce coiling, but not burst swimming, is reduced in mutants. n.s., not significant.