We have developed the highly efficient transposon system in vertebrates by using the Tol2 transposable element from Japanese medaka fish. Further, in a model vertebrate zebrafish, we have developed powerful genetic methods, including the transposon-mediated transgenesis, gene trap, enhancer trap, and Gal4-UAS methods. By using these methods, we created a large number of transgenic fish lines that express the yeast Gal4 transcription activator in specific cells, tissues and organs. We are collaborating researchers all over the world based on the transgenic fish resources. Furthermore, we are studying the structure and function of specific neuronal circuits that regulate complex behaviors such as learning and memory by genetic approaches and calcium imaging.
(A) Adult zebrafish. (B, C) Neuronal circuits essential for fear conditioning in zebrafish (Lal et al. 2018). (D) Prey hunting in zebrafish (Muto et al. 2017). (E) A developmental mechanism of abducens neurons in zebrafish (Asakawa and Kawakami 2018).
Shiraki T, Kawakami K. A tRNA-based multiplex sgRNA expression system in zebrafish and its application to generation of transgenic albino fish. Sci Rep. 2018 Sep 6;8(1):13366.
Lal P, Tanabe H, Suster ML, Ailani D, Kotani Y, Muto A, Itoh M, Iwasaki M, Wada H, Yaksi E, Kawakami K. Identification of a neuronal population in the telencephalon essential for fear conditioning in zebrafish. BMC Biol. 2018 Apr 25;16(1):45.
Asakawa K, Kawakami K. Protocadherin-Mediated Cell Repulsion Controls the Central Topography and Efferent Projections of the Abducens Nucleus. Cell Rep. 2018 Aug 7;24(6):1562-1572.
Muto A, Lal P, Ailani D, Abe G, Itoh M, Kawakami K. Activation of the hypothalamic feeding centre upon visual prey detection. Nat Commun. 2017 Apr 20;8:15029.