Polymorphisms and DNA methylation level in the CpG site of the GHR1 gene associated with mRNA expression, growth traits and hormone level of half-smooth tongue sole (Cynoglossus semilaevis)
The objectives of the present study were to estimate the GHR1 gene mutations and methylation status of CpGs, and whether those mutations and methylation were involved in the regulation of GHR1 gene expression, hormone level and growth traits in half-smooth tongue sole (Cynoglossus semilaevis). Identification of single-nucleotide polymorphisms was performed on 43 male fish. Through polymerase chain reaction-single-strand conformation polymorphism and sequencing, two SNPs were found. SNP1 [c.G1357A (p.Val376Ile)] creating one CpG site located in exon 8 was named L1 locus, and SNP2 (c.G1479A) located in exon 9 was named L2 locus. Individuals were divided into three genotypes, AA, AG and GG according to L1 locus (GG genotype had one more CpG site because of the mutation), and into two genotypes, AA- and GG-based on L2 locus. The results showed that only L1 locus was significantly associated with body weight (P < 0.01), gonad weight (P ≤ 0.05), triiodothyronine (T3) level (P ≤ 0.05) and mRNA expression (P < 0.01). At L1 locus, newly created CpG site in GG genotype was highly methylated (93.3 %), while there was no difference of methylation level in the other two CpG sites among three genotypes. AA genotype and AG genotype having higher T3 level were significantly different (P ≤ 0.05) from GG genotype. There were significant differences among body weights of AA, AG and GG genotypes (P < 0.01). Gonad weights of AA genotype and AG genotype were significantly lower than GG genotype. The GHR1 mRNA expression of GG genotype was significantly lower than AA and AG genotypes (P < 0.01). These implied that mutations and methylation status of GHR1 gene might influence the hormone level, growth traits and gene expression in male half-smooth tongue sole and the L1 locus could be regarded as a potential candidate genetic and epigenetic marker in half-smooth tongue sole selection.
KeywordsGHR gene SNPs DNA methylation Gene expression Growth traits Half-smooth tongue sole (Cynoglossus semilaevis)
This work was supported by State 863 High-Technology R&D Project of China (2012AA10A403) and National Nature Science Foundation of China (31130057).
- Calduch-Giner JA, Mingarro M, Vega-Rubin de Celis S, Boujard D, Perez-Sanchez J (2003) Molecular cloning and characterization of gilthead sea bream (Sparus aurata) growth hormone receptor (GHR). Assessment of alternative splicing. Comp Biochem Physiol B: Biochem Mol Biol 136:1–13CrossRefGoogle Scholar
- Chen SL, Zhang GJ, Shao CW, Huang QF, Liu G, Zhang P, Song WT, An N, Chalopin D, Volff J-N, Hong YH, Li QY, Sha ZX, Zhou HL, Xie MS, Yu QL, Liu Y, Xiang H, Wang N, Wu K, Yang CG, Zhou Q, Liao XL, Yang LF, Hu QM, Zhang JL, Meng L, Jin LJ, Tian YS, Lian JM, Yang JF, Miao GD, Liu SS, Liang Z, Yan F, Li YZ, Sun B, Zhang H, Zhang J, Zhu Y, Du M, Zhao YW, Schart M, Tang QS, Wang J (2014) Whole-genome sequence of a flatfish provides insights into ZW sex chromosome evolution and adaptation to a benthic lifestyle. Nat Genet 46(3):53–260CrossRefGoogle Scholar
- Fox BK, Breves JP, Davis LK, Pierce AL, Hirano T, Grau EG (2010) Tissue-specific regulation of the growth hormone/insulin-like growth factor axis during fasting and re-feeding: importance of muscle expression of IGF-I and IGF-II mRNA in the tilapia. Gen Comp Endocrinol 166(3):573–580PubMedCrossRefGoogle Scholar
- Godowski PJ, Leung DW, Meacham LR, Galgani JP, Hellmiss R, Keret R, Rotwein PS, Parks JS, Laron Z, Wood WI (1989) Characterization of the human growth hormone receptor gene and demonstration of a partial gene deletion in two patients with Laron-type dwarfism. Proc Natl Acad Sci USA 86:8083–8087PubMedCentralPubMedCrossRefGoogle Scholar
- Maj A, Strzałkowska N, Słoniewski K, Krzyzewski J, Oprzadek J, Zwierzchowski L (2004) Single nucleotide polymorphism (SNP) in the 5′-noncoding region of the bovine growth hormone receptor gene and its association with dairy production traits in Polish Black-and-White cattle, Czech. J Anim Sci 49:419–429Google Scholar
- Ni J, You F, Yu SH, Zhang PJ, Xu DD, Wu ZH, Wen AY, Xu YL (2008) Microsatellite polymorphism analysis of GHR gene promoter region in Paralichthys olivaceus hatchery stocks and its association with growth traits. Periodic Ocean Univ China 38(5):719–725Google Scholar
- Saera-Vila A, Calduch-Giner JA, Prunet P, Pérez-Sánchez J (2009) Dynamics of liver GH/IGF axis and selected stress markers in juvenile gilthead sea bream (Sparus aurata) exposed to acute confinement: differential stress response of growth hormone receptors. Comp Biochem Physiol A: Mol Integr Physiol 154(2):197–203CrossRefGoogle Scholar
- Tao WJ, Ma LJ, Ruan RX, Yu JH (2011) SNP loci associated with weight gain on growth hormone receptor genes in Cyprinus carpio var. Jian. Acta Hydrobiol Sin 35(4):622–629Google Scholar
- Tollet P, Enberg B, Mode A (1990) Growth hormone (GH) regulation of cytochrome P-450IIC1, insulin-like growth factor-I (IGF-I), and GH receptor messenger RNA expression in primary rat hepatocytes: a hormonal interplay with insulin, IGF-I, and thyroid hormone. Mol Endocrinol 4:1934–1942PubMedCrossRefGoogle Scholar
- Zhang L, Huang XG, Jiao BW, Wu FR, Wang DS (2006) The structure analysis, tissue distribution and hormonal regulation of two distinct growth hormone receptors in southern catfish Silurus meridionalis. Acta Zool Sin 52(6):1096–1106Google Scholar
- Zhao R, Muehlbauer E, Decuypere E, Grossmann R (2004) Effect of genotype–nutrition interaction on growth and somatotropic gene expression in the chicken. Gen Comp Endocrinol 136(1):2–11Google Scholar