The FTO Gene Is Associated with Growth and Omega-3/-6 Ratio in Asian Seabass
Polymorphisms in the FTO gene are associated with obesity and body mass index in humans and livestock. Little information of whether FTO plays an important role in aquaculture fish species is available. We cloned and characterized the FTO gene in an economically important food fish species: Asian seabass (Lates calcarifer). The full-length cDNA of the gene is 3679 bp, containing an ORF of 1935 bp encoding 644 amino acids, a 216 bp 5′ UTR and a 1538 bp 3′ UTR. The gene consisted of nine exons and eight introns and was 117,679 bp in length. Phylogenetic analysis revealed that the gene in Asian seabass was closely related to those of Japanese flounder and Nile tilapia. Analysis of its expressions using qRT-PCR showed that it was expressed ubiquitously, but was higher in the liver, stomach and intestine. Comparative analysis of the genomic sequences of part of intron 1 of the gene among 10 unrelated individuals identified two SNPs. Analysis of associations between SNPs and traits (i.e. growth, oil content, omega-3 and -6 contents) in an F2 family demonstrated that the two SNPs were significantly associated with growth, oil content, omega-3 content and omega-3/-6 ratio. Altogether, our data suggest that the gene or/and its linked genes play an important role in growth and fatty acid synthesis, and that the SNPs associated with traits may be used as markers for selecting quicker growth and higher omega-3/-6 ratio at the fingerling stage.
KeywordsFTO Polymorphism Trait Breeding Aquaculture
We thank our colleagues Zi Yi Wan, Hong Yan Pang, Yan Fei Wen and Bing Liang for supplying technical support for this work, and Baoqing Ye for editing the English of this manuscript.
This research was supported by the National Research Foundation, Prime Minister’s Office, Singapore, under its Competitive Research Program (CRP Award No. NRF-CRP7-2010-01) and the internal fund of Temasek Life Sciences Laboratory, Singapore.
Compliance with Ethical Standards
All handling of fish was conducted in accordance with the guidelines on the care and use of animals for scientific purposes set up by the Institutional Animal Care and Use Committee (IACUC) of the Temasek Life Sciences Laboratory, Singapore. The IACUC has specially approved this study within the project “Breeding of Asian seabass” (approval number is TLL (F)-12-004).
Conflict of Interest
The authors declare that they have no competing interests.
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