Zebrafish is an excellent model animal to study vertebrate morphogenesis, organogenesis and behaviors by genetic approaches. We have developed novel genetic methodologies by using the medaka fish Tol2 transposable element in zebrafish. We developed the gene trap and enhancer trap methods and generated a large number of transgenic fish expressing a reporter gene or the Gal4 transcription activator in specific cells, tissues and organs during development. By analyzing these transgenic fish, we have discovered novel important developmental genes and neural circuits regulating behaviors. These studies should lead to understanding of genetic and molecular mechanisms underlying vertebrate development and behaviors.

Urasaki, A., Asakawa, K., and Kawakami, K. (2008). Efficient transposition of the Tol2 transposable element from a single-copy donor in zebrafish. Proc. Natl. Acad. Sci. USA 105, 19827-19832.

Urasaki, A., Mito, T., Noji, S., Ueda, R., and Kawakami, K. (2008). Transposition of the vertebrate Tol2 transposable element in Drosophila melanogaster . Gene 425, 64-68.

Kotani, T., and Kawakami, K. (2008). misty somites, a maternal effect gene identified by transposon-mediated insertional mutagenesis in zebrafish that is essential for the somite boundary maintenance. Developmental Biology 316(2), 383-396.

Asakawa, K., Suster, M.L., Mizusawa, K., Nagayoshi, S., Kotani, T., Urasaki, A., Kishimoto, Y., Hibi, M., and Kawakami, K. (2008). Genetic dissection of neural circuits by Tol2 transposon-mediated Gal4 gene and enhancer trapping in zebrafish. Proc. Natl. Acad. Sci. USA 105, 1255-1260.

Nagayoshi, S., Hayashi, E., Abe, G., Osato, N., Asakawa, K., Urasaki, A., Horikawa, K., Ikeo, K., Takeda, H., and Kawakami, K. (2008). Insertional mutagenesis by the Tol2 transposon-mediated enhancer trap approach generated mutations in two developmental genes: tcf7 and synembryn-like. Development 135, 159-169.

Kawakami, K. (2007). Tol2: a versatile gene transfer vector in vertebrates. Genome Biology 8, Suppl 1:S7 .