title: SNP and haplotype analysis reveal IGF2 variants associated with growth traits in Chinese Qinchuan cattle.
abstract: Insulin-like growth factor 2 (IGF2) is a potent cell growth and differentiation factor and is implicated in mammals' growth and development. The objective of this study was to evaluate the effects of the mutations in the bovine IGF2 with growth traits in Chinese Qinchuan cattle. Four single nucleotide polymorphisms (SNPs) were detected of the bovine IGF2 by DNA pool sequencing and forced polymerase chain reaction-restriction fragment length polymorphism (forced PCR-RFLP) methods. We also investigated haplotype structure and linkage disequilibrium (LD) coefficients for four SNPs in 817 individuals representing two main cattle breeds from China. The result of haplotype analysis showed eight different haplotypes and 27 combined genotypes within the study population. The statistical analyses indicated that the four SNPs, combined genotypes and haplotypes are associated with the withers height, body length, chest breadth, chest depth and body weight in Qinchuan cattle population (P < 0.05 or <0.01). The mutant-type variants and mutant haplotype (Hap 8: ATGG; likely to be the beneficial QTN allele) was superior for growth traits; the heterozygote diplotype was associated with higher growth traits compared to wild-type homozygote. Our results provide evidence that polymorphisms in the IGF2 gene are associated with growth traits, and may be used for marker-assisted selection in beef cattle breeding program.
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China.
authors.forename: Yong-Zhen
authors.initials: YZ
authors.lastname: Huang
authors.forename: Zhao-Yang
authors.initials: ZY
authors.lastname: Zhan
authors.forename: Xin-Yi
authors.initials: XY
authors.lastname: Li
authors.forename: Sheng-Ru
authors.initials: SR
authors.lastname: Wu
authors.forename: Yu-Jia
authors.initials: YJ
authors.lastname: Sun
authors.forename: Jing
authors.initials: J
authors.lastname: Xue
authors.forename: Xian-Yong
authors.initials: XY
authors.lastname: Lan
authors.forename: Chu-Zhao
authors.initials: CZ
authors.lastname: Lei
authors.forename: Chun-Lei
authors.initials: CL
authors.lastname: Zhang
authors.forename: Yu-Tang
authors.initials: YT
authors.lastname: Jia
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
mesh_terms: D000818:Animals; D001835:Body Weight / Q000235:genetics*; D001947:Breeding; D002417:Cattle; D002681:China; D005838:Genotype; D006239:Haplotypes; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D015810:Linkage Disequilibrium; D020641:Polymorphism, Single Nucleotide; D019655:Quantitative Trait, Heritable
chemical_list: C035170:IGF2 protein, human; D007335:Insulin-Like Growth Factor II