Studies On Associations Between Polymorphism Of LPL And H-FABP Gene And Performance Of Growth And Development Traits In Yaks

In order to obtain growth and development traits associated with the yak DNA marker, improve the performance and speed up the breeding process of yak.The bioinformatics, DNA sequencing and PCR-SSCP techniques were applied to not only clone the LPL gene, but also analyzed and the polymorphisms of its 9 exons and 3 introns were researched in 398 yaks, which comprised of five breeds, namely, Tianzhu Yak, Gannan Yak, Qinghai gao yuan Yak Xinjiang yak and Datong Yak. The two function genes including LPL gene(exon 1～9, intron 3), H-FABP gene( exon 1～4, intron 1～3) were analyzed in genetics and variation. The developmental traits include weight, body height, stem length, Heart-girth. The results were shown as the following:(1) The yak LPL gene, with a 1485 bp length coding region, codes 495 amino acid. Using the software online, Yak LPL protein secondary structure in the main spiral; no transmembrane structure, containing two domains: Pancreat and PLAT domain. The 23 amino acid in the front of LPL protein is a signal peptide.(2) The polymorphism site was found in the 7 exon LPL gene in yak for the first time. The reason causing the polymorphism is C→G transition and the polymorphism is controlled by a pair of allele A and B, and Allele A is the advantage of the five groups of alleles. The significantly associations of the polymorphism with weight, height and heart-girth were observed (P<0.05), individuals with genotype BB were surpass than that of genotype AA and AB in weight, height and heart-girth.(3) Three polymorphism sites were found in the yak's H-FABP gene, and these were only found in the intron 1, intron 2 and intron 3. In intron 1 polymorphism site showed that A→G transition caused this polymorphism. The associations of the polymorphism with weight were predominanced (P<0.05), with heart-girth were extremely predominanced (P<0.01).In intron 2 polymorphism site showed that T→C transition caused this polymorphism. In this site allele A and B are in balanced condition. The associations of the polymorphism with weight, stem length, and heart-girth were predominanced (P<0.05). Individuals with BB mutation were significantly higher than AA, AB Individuals in this data. In intron 3 polymorphism site we do not found mutational homozygote, and only few of mutants. The associations of the polymorphism with weight, body height, stem length, and heart-girth were not predominanced (P>0.05).In this study, we obtained three-point DNA marker with the yak traits related to growth and development, for yak genetic resources protection, development and utilization, as well as DNA markers in marker-assisted selection in the development and improvement provide a scientific basis.