Establishment And Research Of Gal4-UAS System In Zebrafish

Development of embryos is a very complicated process, in which many genes andsignaling pathways, including TGF-β, Fgf, Wnt and BMP, etc, play important rolestogether.Gal4-UAS system, as a dual expression system, is made up by two parts: the GAL4gene, encoding the yeast transcription activator protein Gal4, and the UAS (UpstreamActivation Sequence), an enhancer to which Gal4specifically binds to activategene transcription. This system enables more effectively study of the signalingpathways or the genes function in a specialized developmental process or a particularorgan. Gal4-UAS system is widely used in drosophila. We aimed to establish it inzebrafish in our study, and try to search the function of BMP signal in specific tissues ororgan through this system.Based on prior work of our lab，in this project, we together made4new UAStransgenic fish through the Gateway method, including4×nrUAS:bmp2b-GFP,4×nrUAS:bmp4-GFP,4×nrUAS:bmp7a-GFP and4×nrUAS:tBr-GFP transgenic fish.Using the target clones GM2:KalTA4-GIpA-5×UASE1b-mCherry-GIpA andef1a:KalTA4-GIpA-5×UASE1b-mCherry-GIpA, we got27tissue-specific expressingGal4VP16/KalTA4fusion protein transgenic lines (short for Gal4lines) together. Bycrossing different tissue-specific Gal4lines with UAS-GFP lines, GFP could bedetected in their offspring embryos in specific tissues. It is proved that the Gal4-UASsystem is successfully established. Furthermore, we preliminary tested the function ofBMP signal in neural tube, retina, heart, neural crest cells, brachial arch and pronephricduct with this system. It seems that the change of BMP signal intensity has no obviousinfluence on the development of these tissues and organs except in brachial arches. Thereason of this phenomenon will be further explored.