title: Cloning of TPO gene and associations of polymorphisms with chicken growth and carcass traits.
abstract: Thyroid peroxidase (TPO), which located on the apical membrane surface of thyrocytes, is the key enzyme involved in thyroid hormone synthesis, mainly catalyses the iodination of tyrosine residues and the coupling of iodotyrosines on thyroglobulin to form thyroxine and triiodothyronine. The objectives of this study were to identify genetic polymorphisms of the chicken TPO gene and to analyze potential association between single nucleotide polymorphisms (SNPs) and growth and carcass traits in chicken. Partial sequences of TPO gene were cloned firstly. The nucleotide sequence was found to have 72 % identity with that of humans. The chicken TPO amino acid sequence was 71 %. Through polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods, three novel mutations of the chicken TPO gene were detected in the F2 resource population from Gushi chickens and Anka broilers. The association analysis indicated that all of the three SNPs showed association with chicken growth at different periods. The g.29996C>T polymorphisms was significantly associated with body weight, breast bone length, pectoral angle at 12 weeks, claw weight and leg muscle weight (P < 0.05). In addition, individuals with the TT genotype had higher value for almost all the traits than CC and CT genotype. Meanwhile for CLW, the additive effects were significant (P < 0.05). Hence, we suggest that genotype TT can be regarded as a potential molecular marker for later growth and carcass traits in chicken.
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Henan Innovative Engineering Research Center of Poultry Germplasm Resource, Zhengzhou 450002, People's Republic of China. lhnhxy@sina.com
authors.forename: Xinyan
authors.initials: X
authors.lastname: Hou
authors.forename: Ruili
authors.initials: R
authors.lastname: Han
authors.forename: Yadong
authors.initials: Y
authors.lastname: Tian
authors.forename: Wanying
authors.initials: W
authors.lastname: Xie
authors.forename: Guirong
authors.initials: G
authors.lastname: Sun
authors.forename: Guoxi
authors.initials: G
authors.lastname: Li
authors.forename: Ruirui
authors.initials: R
authors.lastname: Jiang
authors.forename: Xiangtao
authors.initials: X
authors.lastname: Kang
mesh_terms: D000818:Animals; D001835:Body Weight / Q000235:genetics; D002645:Chickens / Q000235:genetics / Q000254:growth & development*; D003001:Cloning, Molecular; D017124:Conserved Sequence; D056726:Genetic Association Studies; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007453:Iodide Peroxidase / Q000235:genetics* / Q000378:metabolism; D008460:Meat; D020641:Polymorphism, Single Nucleotide; D019655:Quantitative Trait, Heritable; D017422:Sequence Analysis, DNA
chemical_list: D007453:Iodide Peroxidase