Fspondin Gene Clone And Its Preliminaryfunction Study In Japanese Flounder (Paralichthys Olivaceus)

The nervous system plays an important roles for regulation to the creature, the livebeing with advanced nervous system was more sensitive to the external simulationand surroundings information, so that they can evolutionary survive in the drasticenvironment owning to the stronger predation ability. In the development of nervoussystem, it is crucial that the nervous cells differentiation and circuit formation for thefunctional establishment. The secretion cells in the floor plate appeared in the earlierdevelopment of nervous system, secreting the various important molecules for theneurogenesis including Fspondin expressed highly at the floor plate. Fspodin is highconservative in the structure, indicating the high similarity between different species.In this study, the full-length of Po-Fspondin was cloned and its structure character andexpression pattern were analyzed. The function of Po-Fspondin to the development ofnervous system was investigated preliminarily by the zebrafish model in vivo. Themethod used and result obtained in this study were provided an example for geneanalysis of the commercial fishes by the zebrafish model in vivo.In this study, the full-length of Po-Fspondin was achieved including215bp5’UTR region,749bp3’UTR region,2421open reading frame (ORF) and808deduced amino acids.The data of biology information analysis indicated thathPo-Fspondin was high conserved in structure and evolution, containingN-terminalReelin domain, Spondin domain and six proper C-terminalthrombospondin type1repeat(TSR1).The real-time quantitative PCR result indicated that Po-Fspondin wassignificantly expressed at the tail bud stages owning to the formation of nervous tube.The analysis of Po-Fspondin expression in tissues showed that the expression wasdetected in the brain, kidney, testis and ovary. The expression of Po-Fspondin wassignificantly expressed in ovary, implying the other function of Po-Fspondin.The gene function of Po-Fspondin to thenervous developmentwas investigated in the model of zebrafish embryos injected into Po-Fspondin mRNA by microinjection,quantitative real time PCR, in situ hybridization (ISH), and observation of greenfluorescence protein (GFP). The result showed that Po-Fspondin could promote thenervous system development in the stage of50%epiboly and36h,72h after incubationin zebrafish, even induce middle precursor cells differentiation to the floor plate, sothat have a profound and wide influence to the nervous system development ofzebrafish.