大白猪MC4R、IGF2和VRTN基因的多态性及其与生产性状的关联分析

发布时间：2018-03-24 20:04

本文选题：猪　切入点：MC4R基因　出处：《华中农业大学》2017年硕士论文

【摘要】：随着分子生物学和现代生物技术的发展,分子标记辅助选择已广泛应用于动物育种中,新一代分子标记SNP(single nucleotide polymorphism,单核苷酸多态性)的出现使得从DNA水平上对猪的相关性状进行选择成为可能,加快了种猪育种进程。本研究以美系大白猪和法系大白猪群体为实验材料,采用PCR-RFLP技术对MC4R(melanocortin-4 receptor,黑素皮质素受体4)、IGF2(insulin-like growth factor 2,胰岛素样生长因子2)和VRTN(vertebrae development homolog,椎体发育同源物)三个功能基因进行了SNP多态性检测及生产性状关联分析,得到以下结果:(1)MC4R基因是与脂肪沉积调控有关的功能基因。本研究关联分析结果表明,在美系和法系大白猪中,MC4R基因Asp298Asn位点(A/G突变)多态性与背膘厚、达100 kg体重日龄等性状存在极显著关联(P0.01);携带G等位基因的个体具有更低的背膘厚度和更快的生长速度,为优势等位基因,并且MC4R基因加性效应达到极其著水平(P0.01)。(2)IGF2基因是与细胞、胚胎生长和组织分化相关的一个关键的生长因子,本研究关联分析结果表明,IGF2基因Intron3中G3072A位点多态性与背膘厚、初生重、达100 kg体重日龄和眼肌面积之间存在极显著关联(P0.01),A等位基因为优势等位基因,对降低背膘厚、增加初生重、增加眼肌面积和提高生长速度有显著影响,并且IGF2基因加性效应均达极显著水平(P0.01)。(3)VRTN基因是影响猪的脊椎数发育的功能基因,本研究关联分析结果表明,VRTN g.20311_20312ins291位点多态性与左乳头数、总乳头数等性状存在显著关联(P0.05),与体长和达100 kg体重日龄存在极显著相关(P0.01),该等位基因是增加体长、增加乳头数和提高生长速度的有利等位基因;在总乳头数性状上,VRTN基因加性效应均达显著水平(P0.05),在体长和达100 kg体重日龄性状上,VRTN基因加性效应达到极显著水平(P0.01)。本研究通过验证了MC4R、IGF2和VRTN基因内的SNP位点与猪生产性状之间的关系,为大白猪重要经济性状的分子标记辅助选择提供了理论依据。
[Abstract]:With the development of molecular biology and modern biotechnology, molecular marker-assisted selection has been widely used in animal breeding. The emergence of a new generation of molecular marker SNP(single nucleotide polymorphisms (SNP) made it possible to select the associated traits of pigs at the DNA level, thus speeding up the breeding process of pigs. PCR-RFLP technique was used to detect the SNP polymorphism of MC4R(melanocortin-4 receptor, IGF2insulin-like growth factor 2 (insulin-like growth factor 2) and VRTN(vertebrae development homologue (homologue of vertebral body). The following results were obtained: the MC4R gene is a functional gene related to the regulation of fat deposition. The results of association analysis showed that the polymorphism of MC4R gene Asp298Asn locus and backfat thickness were found in American and legal white pigs. There was a significant correlation between the traits of 100 kg BW / d and other traits, and the individuals with G allele had lower backfat thickness and faster growth rate, so they were the dominant alleles. Moreover, the additive effect of MC4R gene reached an extremely high level. The gene P0.01P0.01. Gf2 was a key growth factor related to cell, embryonic growth and tissue differentiation. The results of association analysis showed that the G3072A locus polymorphism and backfat thickness, primary weight in Intron3 of the IGF2 gene were related to the growth of cells, embryo growth and tissue differentiation, and the results of association analysis showed that the G3072A locus polymorphism was associated with backfat thickness. There was a very significant correlation between 100 kg BW / d age and eye muscle area. The P0.01A allele was the dominant allele, which had a significant effect on reducing backfat thickness, increasing birth weight, increasing eye muscle area and increasing growth rate. In addition, the additive effect of IGF2 gene was very significant. P0.01N. 3VRTN gene was a functional gene affecting the development of pig spinal cord. The results of association analysis showed that the polymorphism of VRTN g.20311_20312ins291 locus and the number of left nipples were related to the number of left nipples. There was a significant correlation between total nipple number and body length and 100 kg body weight. The allele was a favorable allele to increase body length, nipple number and growth rate. The additive effect of VRTN gene on total nipple number was significant (P0.05), and on body length and 100kg BW / day traits, the additive effect of VRTN gene reached very significant level (P0.01). In this study, the SNP loci in MC4RRIGF2 and VRTN genes were verified. The relationship between pig production traits, It provides a theoretical basis for molecular marker-assisted selection of important economic traits in large white pigs.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S828

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