wnt signaling is required for early development of zebrafish swimbladderwnt信号是斑马鱼swimbladder的早期发展所需.pdf

Wnt Signaling Is Required for Early Development of Zebrafish Swimbladder 1 1 1 1,2 1 Ao Yin , Svitlana Korzh , Cecilia L. Winata , Vladimir Korzh *, Zhiyuan Gong * 1 Department of Biological Sciences, National University of Singapore, Singapore, Singapore, 2 Laboratory of Fish Developmental Biology, Genes and Development Division, Institute of Molecular and Cell Biology, Singapore, Singapore Abstract Background: Wnt signaling plays critical roles in mammalian lung development. However, Wnt signaling in the development of the zebrafish swimbladder, which is considered as a counterpart of mammalian lungs, have not been explored. To investigate the potential conservation of signaling events in early development of the lung and swimbladder, we wish to address the question whether Wnt signaling plays a role in swimbladder development. Methodology/Principal Findings: For analysis of zebrafish swimbladder development, we first identified, by whole-mount in situ hybridization (WISH), has2 as a mesenchymal marker, sox2 as the earliest epithelial marker, as well as hprt1l and elovl1a as the earliest mesothelial markers. We also demonstrated that genes encoding Wnt signaling members Wnt5b, Fz2, Fz7b, Lef1, Tcf3 were expressed in different layers of swimbladder. Then we utilized the heat-shock inducible transgenic lines hs:Dkk1-GFP and hs:DTcf-GFP to temporarily block canonical Wnt signaling. Inhibition of canonical Wnt signaling at various time points disturbed precursor cells specification, organization, anterioposterior patterning, and smooth muscle differentiation in all three tissue layers of swimbladder. These observations were also confirme