title: Mapping quantitative trait loci for omega-3 fatty acids in Asian seabass.
abstract: Omega-3 fatty acids are essential fatty acids for human health. Therefore, increasing both percentage of omega-3 and a better fatty acid profile in fish fillets is one of the breeding goals in aquaculture. However, it is difficult to increase the omega-3 content in fish fillets, as the phenotypic selection of these traits is not easily feasible. To facilitate the genetic improvement of the Asian seabass for optimal fatty acid profiles, a genome-wide scan for quantitative trait loci (QTL) affecting fatty acid level in the flesh of the Asian seabass was performed on an F2 family containing 314 offspring. All family members were genotyped using 123 informative microsatellites and 22 SNPs. High percentages of n-3 polyunsaturated fatty acids (PUFA), especially C22:6 (DHA 16.48 ± 3.09 %) and C20:5 (EPA 7.19 ± 0.86 %) were detected in the flesh. One significant and 54 suggestive QTL for different fatty acids and a water content trait were detected on the whole genome. QTL for C18:0b was located on linkage groups (LG) 5. QTL for total n-3 PUFA content in flesh were mapped onto LG6 and LG23 with the phenotypic variance explained ranging from 3.8 to 6.3 %. Four QTL for C22:6 were detected on LG6, LG23, and LG24, explaining 3.9 to 4.9 % of the phenotypic variance, respectively. Mapping of QTL for contents of different fatty acids is the first step towards improving the omega-3 content in the fillets of fish by using marker-assisted selection and is important for understanding the biology of fatty acid deposition.
authors.affiliation: Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604, Singapore.
authors.forename: Jun Hong
authors.initials: JH
authors.lastname: Xia
authors.forename: Grace
authors.initials: G
authors.lastname: Lin
authors.forename: Xiaoping
authors.initials: X
authors.lastname: He
authors.forename: Bu
authors.initials: B
authors.lastname: Yunping
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Fei
authors.initials: F
authors.lastname: Sun
authors.forename: Rongjian
authors.initials: R
authors.lastname: Tu
authors.forename: Gen Hua
authors.initials: GH
authors.lastname: Yue
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D015525:Fatty Acids, Omega-3 / Q000032:analysis* / Q000235:genetics*; D005819:Genetic Markers / Q000235:genetics; D005828:Genetics, Population; D005838:Genotype; D008126:Lod Score; D008957:Models, Genetic; D010473:Perciformes / Q000235:genetics*; D010641:Phenotype; D040641:Quantitative Trait Loci / Q000235:genetics*
chemical_list: D015525:Fatty Acids, Omega-3; D005819:Genetic Markers