[Locomotion research with zebrafish].

Recent genetic analysis of behavior was successfully performed in C. elegans and Drosophila. However, since the organization and morphology of their nervous system is different from those of vertebrates, it is unclear how applicable these findings are for vertebrates. Additionally, electrophysiological analysis is difficult in these invertebrates. On the other hand, electrophysiology is well established in vertebrate animals, such as mice and Xenopus, but large-scale mutagenesis is costly and difficult with these vertebrates. I started a genetic analysis of behavior in zebrafish to overcome these difficulties. First, zebrafish can be studied using large-scale mutagenesis. Second, electrophysiological methods are available to analyze the CNS, NMJ and muscles in zebrafish. Third, the early behaviors are simple and stereotyped in zebrafish embryos. Fourth, zebrafish embryos are transparent making it possible to visualize dynamic events in vivo such as Ca transients and axon outgrowth. These advantages make the zebrafish an ideal research tool for functional development of neurons and muscles. I characterized accordion and bandoneon mutants, which were defective in calcium pump in muscle and glycine receptor in the CNS, respectively. Interestingly, both of these mutants exhibited similar simultaneous bilateral muscle contraction and shortening of the tail in response to touch.