Fig. 1. ryr mutant embryos exhibit slow swimming and weak muscle contractions in response to touch. (A-E) Mechanosensory stimulation induced a wild-type embryo (48 hpf) to swim away rapidly. (F-O) Touch induced an ryr mutant embryo (48 hpf) to swim, but only slowly. (P) Superimposition of all the frames from a video showing normal displacement of the trunk and tail during a swimming episode induced by tactile stimulation of a wild-type sibling. (Q) Displacement of the trunk and tail during swimming in ryr mutants is smaller compared with that of wild-type siblings. For P and Q, the heads of embryos were pinned on a Sylgard dish leaving most of the trunk and tail free.