title: The LBP gene and its association with resistance to Aeromonas hydrophila in tilapia.
abstract: Resistance to pathogens is important for the sustainability and profitability of food fish production. In immune-related genes, the lipopolysaccharide-binding protein (LBP) gene is an important mediator of the inflammatory reaction. We analyzed the cDNA and genomic structure of the LBP gene in tilapia. The full-length cDNA (1901 bp) of the gene contained a 1416 bp open reading frame, encoding 471 amino acid residues. Its genomic sequence was 5577 bp, comprising 15 exons and 14 introns. Under normal conditions, the gene was constitutively expressed in all examined tissues. The highest expression was detected in intestine and kidney. We examined the responses of the gene to challenges with two bacterial pathogens Streptcoccus agalactiae and Aeromonas hydrophila. The gene was significantly upregulated in kidney and spleen post-infection with S. agalactiae and A. hydrophila, respectively. However, the expression profiles of the gene after the challenge with the two pathogens were different. Furthermore, we identified three SNPs in the gene. There were significant associations (p < 0.05) of two of the three SNPs with the resistance to A. hydrophila, but not with the resistance to S. agalactiae or growth performance. These results suggest that the LBP gene is involved in the acute-phase immunologic response to the bacterial infections, and the responses to the two bacterial pathogens are different. The two SNPs associated with the resistance to A. hydrophila may be useful in the selection of tilapia resistant to A. hydrophila.
authors.affiliation: Molecular Population Genetics & Breeding Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore. snow03221@163.com.
authors.forename: Gui Hong
authors.initials: GH
authors.lastname: Fu
authors.affiliation: Molecular Population Genetics & Breeding Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore. liufeng@tll.org.sg.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Molecular Population Genetics & Breeding Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore. xiajunh3@mail.sysu.edu.cn.
authors.forename: Jun Hong
authors.initials: JH
authors.lastname: Xia
authors.affiliation: Molecular Population Genetics & Breeding Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore. genhua@tll.org.sg.
authors.forename: Gen Hua
authors.initials: GH
authors.lastname: Yue
mesh_terms: D000209:Acute-Phase Proteins / Q000235:genetics* / Q000378:metabolism; D016980:Aeromonas hydrophila / Q000502:physiology*; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D003198:Computer Simulation; D018076:DNA, Complementary / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics* / Q000276:immunology; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D008040:Genetic Linkage; D016678:Genome; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D019655:Quantitative Trait, Heritable; D017422:Sequence Analysis, DNA; D017210:Tilapia / Q000235:genetics* / Q000254:growth & development / Q000276:immunology / Q000382:microbiology*; D000099231:Lipopolysaccharide-Binding Protein
chemical_list: D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D018076:DNA, Complementary; D029941:Fish Proteins; D008562:Membrane Glycoproteins; D000099231:Lipopolysaccharide-Binding Protein