title: Association of IGF-I gene polymorphisms with milk yield and body size in Chinese dairy goats.
abstract: The association of IGF-I gene polymorphisms with certain traits in 708 individuals of two Chinese dairy-goat breeds (Guanzhong and Xinong Saanen) was investigated. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing methods were employed in screening for genetic variation. Two novel mutations were detected in the 5'-flanking region and in intron 4 of IGF-I gene, viz., g.1617 G > A and g.5752 G > C (accession D26119.2), respectively. The associations of the g.1617 G > A mutation with milk yield and the body size were not significant (p > 0.05). However, in the case of g.5752 G > C, Xinong Saanen dairy goats with the CG genotype presented longer bodies (p < 0.05). Chest circumference (p < 0.05) was larger in Guanzhong goats with the GG genotype. In Xinong Saanen dairy goats with the CC genotype, milk yields were significantly higher during the first and second lactations (p < 0.05). Hence, the g.5752 G > C mutation could facilitate association analysis and serve as a genetic marker for Chinese dairy-goat breeding and genetics.
authors.affiliation: Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest AF University, Yangling, Shaanxi China.
authors.forename: Chanjuan
authors.initials: C
authors.lastname: Deng
authors.forename: Rongnuan
authors.initials: R
authors.lastname: Ma
authors.forename: Xiangpeng
authors.initials: X
authors.lastname: Yue
authors.forename: Xianyong
authors.initials: X
authors.lastname: Lan
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.forename: Chuzhao
authors.initials: C
authors.lastname: Lei