title: A genome scan revealed significant associations of growth traits with a major QTL and GHR2 in tilapia.
abstract: Growth is an important trait in animal breeding. However, the genetic effects underpinning fish growth variability are still poorly understood. QTL mapping and analysis of candidate genes are effective methods to address this issue. We conducted a genome-wide QTL analysis for growth in tilapia. A total of 10, 7 and 8 significant QTLs were identified for body weight, total length and standard length at 140 dph, respectively. The majority of these QTLs were sex-specific. One major QTL for growth traits was identified in the sex-determining locus in LG1, explaining 71.7%, 67.2% and 64.9% of the phenotypic variation (PV) of body weight, total length and standard length, respectively. In addition, a candidate gene GHR2 in a QTL was significantly associated with body weight, explaining 13.1% of PV. Real-time qPCR revealed that different genotypes at the GHR2 locus influenced the IGF-1 expression level. The markers located in the major QTL for growth traits could be used in marker-assisted selection of tilapia. The associations between GHR2 variants and growth traits suggest that the GHR2 gene should be an important gene that explains the difference in growth among tilapia species.
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.
authors.forename: Fei
authors.initials: F
authors.lastname: Sun
authors.affiliation: Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore.
authors.forename: Jun Hong
authors.initials: JH
authors.lastname: Xia
authors.affiliation: Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
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: Grace
authors.initials: G
authors.lastname: Lin
authors.affiliation: Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore.
authors.forename: Rong Jian
authors.initials: RJ
authors.lastname: Tu
authors.affiliation: Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore.
authors.forename: Zi Yi
authors.initials: ZY
authors.lastname: Wan
authors.affiliation: Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore.
authors.forename: Delia
authors.initials: D
authors.lastname: Quek
authors.affiliation: 1] Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore [2] Department of Biological Sciences, National University of Singapore, 14 Science Drive, Singapore 117543.
authors.forename: Gen Hua
authors.initials: GH
authors.lastname: Yue
mesh_terms: D000818:Animals; D001483:Base Sequence; D001835:Body Weight / Q000235:genetics*; D002874:Chromosome Mapping / Q000379:methods; D016678:Genome / Q000235:genetics*; D008969:Molecular Sequence Data; D040641:Quantitative Trait Loci / Q000235:genetics*; D011986:Receptors, Somatotropin / Q000235:genetics*; D012727:Sex Characteristics; D017210:Tilapia / Q000235:genetics* / Q000254:growth & development*
chemical_list: D011986:Receptors, Somatotropin