title: Cloning and characterization of the gene for L-amino acid oxidase in hybrid tilapia.
abstract: Tilapia is the common name for a group of cichlid fishes. Identification of DNA markers significantly associated with important traits in candidate genes may speed up genetic improvement. L-Amino acid oxidase (LAO) plays a crucial role in the innate immune defences of animals. Previously, whether LAO variants were associated with economic traits had not been studied in fish. We characterized the cDNA sequence of the LAO gene of hybrid tilapia (Oreochromis spp.). Its ORF was 1536 bp, encoding a flavoenzyme of 511 amino acids. This gene consisted of seven exons and six introns. Its expression was detected in the intestine, blood, kidney, skin, liver. It was highly expressed in the intestine. After a challenge with a bacterial pathogen, Streptococcus agalactiae, its expression was up-regulated significantly in the liver, intestine and spleen (P < 0.05). We identified one SNP in the genomic sequence of the gene and found that this SNP was associated significantly with body length (P < 0.05), but not with resistance to S. agalactiae. The results of this study suggest that the LAO gene plays an important role in innate immune responses to the bacterial pathogen in tilapia. The investigation of relationship between polymorphism of LAO gene and disease resistance and growth in tilapia showed that one SNP was associated significantly with body length. Further experiments on whether SNPs in the LAO gene are associated with growth in tilapia and other populations could be useful in understanding more functions of the LAO gene.
authors.affiliation: Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604, Republic of Singapore.|Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China.
authors.forename: Yubang
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Molecular Population Genetics 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 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 Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604, Republic of Singapore. genhua@tll.org.sg.|Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Republic of Singapore. genhua@tll.org.sg.|School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore. genhua@tll.org.sg.
authors.forename: Gen Hua
authors.initials: GH
authors.lastname: Yue
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D060467:Disease Resistance / Q000235:genetics; D005260:Female; D029941:Fish Proteins / Q000235:genetics*; D005786:Gene Expression Regulation; D050830:L-Amino Acid Oxidase / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D016415:Sequence Alignment; D013290:Streptococcal Infections; D013292:Streptococcus agalactiae; D017210:Tilapia / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology
chemical_list: D029941:Fish Proteins; D050830:L-Amino Acid Oxidase
keywords: L-Amino acid oxidase; SNP; Streptococcus agalactiae; Tilapia