Investigation of ttbk2a and ttbk2b function in the zebrafish

• Main Authors: Yu-Ting Wang, 王又婷
• Other Authors: Bon-Chu Chung
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/262mh6

碩士 === 國立中央大學 === 生命科學系 === 106 === The primary cilium plays a critical role in the development of vertebrate nervous system. However, the function of primary cilia in brain remains unclear. Tau tubulin kinase 2 (TTBK2) is a regulator required for primary cilium formation, and its transcript can be detected in the brain. In human, mutations in TTBK2 serine rich domain cause spinocerebellar ataxia type 11 (SCA11) and the cerebellum will undergo degeneration. TTBK2 is essential for brain development, yet the mechanism is still elusive. Therefore, I focus on ttbk2a and ttbk2b in zebrafish. Zebrafish is a powerful model for the study of human disease. In this study, I characterized ttbk2a and ttbk2b RNA expression pattern during embryogenesis and in the adult tissues using RT-PCR and in situ hybridization. The ttbk2a and ttbk2b transripts started to be expressed after 3 dpf, and ttbk2b was also expressed transiently from the 1-cell stage to 50％ epiboly. Both ttbk2a and ttbk2b transcripts were detected in several adult fish brain regions, such as ventral telencephalic area (Vd), medial zone of dorsal telencephalic area (Dm), periventricular grey zone of optic tectum (PGZ), lateral division of valvula cerebelli (Val), and corpus cerebelli (Cce). To investigate ttbk2 function, I generated ttbk2 mutants by CRISPR-Cas9 system to create mutations mimicking human patients and disrupting the most important domains of ttbk2. I already obtained 5 lines of F1 fish. One G0 fish had reduced ability to swim in the swim tunnel assay, indicating that ttbk2 mutation may affect zebrafish swimming behavior. These mutant fish will be a useful tool to investigate the function and mechanism of ttbk2 and primary cilia.