title: Characterization of F-spondin in Japanese flounder (Paralichthys olivaceus) and its role in the nervous system development of teleosts.
abstract: F-spondin was originally isolated from the developing embryonic floor plate of vertebrates, secreting numerous kinds of neuron-related molecules. The protein performs a positive function in nervous system development, which is attributed to the high conservation of F-spondin protein, an extracellular matrix (ECM) protein in several species. However, its precise function remains unknown, especially in marine fish. In this study, the F-spondin of Japanese flounder (Paralichthys olivaceus). was cloned, and its expression pattern and structural characteristics were analyzed. The 2421bp-long cDNA ORF of PoF-spondin was obtained and divided into 14 exons spread over 61,496bp of the genomic sequence. Phylogenetic analysis showed that PoF-spondin was actually the ortholog of the human spon1 gene and shared high identities with other teleost spon1a genes. Quantitative RT-PCR analysis showed that PoF-spondin was maternally expressed, and transcripts were present from one-cell stage to hatching stage, peaking at tailbud stage. Tissue distribution analysis indicated that PoF-spondin was detectable mainly in the gonads (especially in the ovary) and the brain. Whole mount in situ hybridization analysis revealed that the PoF-spondin transcription distributed throughout the cleavage of the ball in the early stage and expressed at a high level in the floor plate of the trunk at tailbud and pre-hatching stages. Furthermore, the expression of genes related to nervous system development (spon1b, foxo3b, and foxj1a) was significantly increased after the injection of PoF-spondin into the embryos of wild-type zebrafish. Furthermore, PoF-spondin significantly suppressed the expression of the chordamesoderm marker gene ntl, increased the expression of otx2/krox20, ectoderm mark genes, and left the expression of dorsal mesodermal marker gene gsc unaffected at 50% epiboly stage in zebrafish. In short, our results suggest that PoF-spondin functions in the development of the teleost nervous system.
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ocean University of China, 266003 Qingdao, Shandong, China.
authors.forename: Hongshuang
authors.initials: H
authors.lastname: Hu
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ocean University of China, 266003 Qingdao, Shandong, China.
authors.forename: Nian
authors.initials: N
authors.lastname: Xin
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ocean University of China, 266003 Qingdao, Shandong, China.
authors.forename: Jinxiang
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ocean University of China, 266003 Qingdao, Shandong, China.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Liu
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ocean University of China, 266003 Qingdao, Shandong, China.
authors.forename: Zhenwei
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ocean University of China, 266003 Qingdao, Shandong, China.
authors.forename: Wenji
authors.initials: W
authors.lastname: Wang
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ocean University of China, 266003 Qingdao, Shandong, China.
authors.forename: Quanqi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, Ocean University of China, 266003 Qingdao, Shandong, China. Electronic address: qijie@ouc.edu.cn.
authors.forename: Jie
authors.initials: J
authors.lastname: Qi
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D016326:Extracellular Matrix Proteins / Q000235:genetics* / Q000378:metabolism*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005432:Flounder / Q000033:anatomy & histology* / Q000196:embryology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006066:Gonads / Q000378:metabolism; D009420:Nervous System / Q000254:growth & development* / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny
chemical_list: D016326:Extracellular Matrix Proteins; D029941:Fish Proteins
keywords: F-spondin; Japanese flounder; Nervous system development; Zebrafish