title: Identification and expression analysis of cobia (Rachycentron canadum) Toll-like receptor 9 gene.
abstract: Cobia culture is hindered by bacterial infection (Photobacterium damselae subsp. piscicida) and in order to study the effect of P. damselae subsp. piscicida challenge and CpG ODN stimulation on cobia Toll like receptor 9 (RCTLR9), we used PCR to clone RCTLR9 gene and qRT-PCR to quantify gene expression. The results indicated that RCTLR9 cDNA contains 3141 bp. It encodes 1047 amino acids containing 16 typical structures of leucine-rich repeats (LRRs) including an LRRTYP, LRRCT and a motif involved in PAMP binding was identified at position 240-253 amino acid. Broad expression of RCTLR9 was found in larval, juvenile and adult stages irrespective of the tissues. In larval stage, RCTLR9 mRNA expression decreased at 5 d and then increased at 10 dph. At juvenile stage cobia, the expression was significantly high (p < 0.05) in spleen and intestine compared to gill, kidney, liver and skin. However, at adult stage, the significant high expression was found in gill and intestine. Cobia challenged with P. damselae subsp. piscicida showed significant increase in RCTLR9 expression at 24 h post challenge in intestine, spleen and liver, while in kidney the expression was peak at 12 h and later it decreased at 24 h. The highest expression was 40 fold increase in spleen and the lowest expression was ∼3.6 fold increase in liver. Cobia stimulated with CpG oligonucleotides showed that the induction of these genes was CpG ODN type and time dependent. In spleen and liver, CpG ODNs 1668 and 2006 injected group showed high expression of RCTLR9, IL-1β, chemokine CC compared to other groups. Meanwhile, CpG ODN 2006 has induced high expression of IgM. The CpG ODNs 2395 have induced significant high expression of Mx in spleen and liver. These results demonstrates the potential of using CpG ODN to enhance cobia resistance to P. damselae subsp. piscicida infection and use as an adjuvant in vaccine development.
authors.affiliation: Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Pingtung, Taiwan.
authors.forename: Omkar
authors.initials: O
authors.lastname: Byadgi
authors.affiliation: Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Pingtung, Taiwan; Department of Fisheries and Marine Science, University of Brawijaya, Malang, Indonesia.
authors.forename: Dinda
authors.initials: D
authors.lastname: Puteri
authors.affiliation: Tungkang Biotechnology Research Center, Fisheries Research Institute, Council of Agriculture, Pingtung, Taiwan.
authors.forename: Yan-Horn
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Pingtung, Taiwan.
authors.forename: Jai-Wei
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Pingtung, Taiwan. Electronic address: cheng.tachih@gmail.com.
authors.forename: Ta-Chih
authors.initials: TC
authors.lastname: Cheng
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007075:Immunoglobulin M / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010473:Perciformes / Q000235:genetics* / Q000254:growth & development / Q000276:immunology*; D010776:Photobacterium / Q000502:physiology; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D051217:Toll-Like Receptor 9 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D016207:Cytokines; D018076:DNA, Complementary; D029941:Fish Proteins; D007075:Immunoglobulin M; D012333:RNA, Messenger; D051217:Toll-Like Receptor 9
keywords: CpG ODNs; Innate immunity; Photobacterium damselae subsp. piscicida; Rachycentron canadum; Toll-like receptor 9