title: Characterization of the duodenase-1 gene and its associations with resistance to Streptococuus agalactiae in hybrid tilapia (Oreochromis spp.).
abstract: Tilapia is a group of cultured teleost fishes whose production is threatened by some diseases. Identification of DNA markers associated with disease resistance in candidate genes may facilitate to accelerate the selection of disease resistance. The gene encoding a duodenase, which can trigger immune response, has not been studied in fish. We characterized the cDNA of duodenase-1 gene of hybrid tilapia. Its ORF is 759 bp, encoding a serine protease of 252 amino acids. This gene consisted of five exons and four introns. Its expression was detected in all 10 tissues examined, and it was highly expressed in the intestine and kidney. After a challenge with the bacterial pathogen, Streptococcus agalactiae, its expression was up-regulated significantly in the intestine, liver and spleen. We identified seven SNPs in the gene and found that four of them were significantly associated with the resistance to S. agalactiae (P < 0.05). The CGTCC haplotype, CAGTC/CGGTC and CGTCC/CGTCC diplotype were significantly associated with the resistance to S. agalactiae (P = 0.00, 0.04 and < 0.0001, respectively). In addition, one SNP was associated significantly with growth traits (P < 0.05). These findings suggest that the duodenase-1 gene plays an important role in the resistance to S. agalactiae in tilapia. The SNP markers in the duodenase-1 gene associated with resistance to the bacterial pathogen, may facilitate the selection of tilapia resistant to the bacterial disease.
authors.affiliation: Molecular Population Genetics & Breeding Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore.
authors.forename: Yubang
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Molecular Population Genetics & Breeding Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore.
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, Republic of Singapore.
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, Republic of Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Republic of Singapore; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore. Electronic address: genhua@tll.org.sg.
authors.forename: Gen Hua
authors.initials: GH
authors.lastname: Yue
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D060467:Disease Resistance / Q000235:genetics* / Q000276:immunology; D029941:Fish Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000276:immunology; D007668:Kidney / Q000276:immunology / Q000378:metabolism; D008099:Liver / Q000276:immunology / Q000378:metabolism; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D012333:RNA, Messenger / Q000378:metabolism; D012697:Serine Endopeptidases / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D012867:Skin / Q000378:metabolism; D013154:Spleen / Q000276:immunology / Q000378:metabolism; D013290:Streptococcal Infections / Q000276:immunology; D013292:Streptococcus agalactiae; D017210:Tilapia / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D012333:RNA, Messenger; D012697:Serine Endopeptidases; C078261:duodenase
keywords: Duodenase-1; Resistance; SNP; Streptococcus agalactiae; Tilapia