四点屠体背膘厚在莱芜猪和二花脸猪中的全基因组关联分析研究

发布时间：2018-05-27 14:09

本文选题：猪 + 背膘厚　；参考：《江西农业大学》2015年硕士论文

【摘要】：背膘厚反映脂肪沉积能力,也是生产中用来度量瘦肉率的指标,因此对背膘厚的遗传解析具有重要经济价值。背膘厚受品种的影响非常大,在中西方猪种之间存在显著差异:大白、长白、杜洛克等西方瘦肉型猪种背膘薄;而莱芜、二花脸等脂肪型猪种背膘厚。随着分子生物技术的发展以及猪60K SNP芯片的出现,国内外许多学者对猪的背膘厚进行了遗传解析,定位了许多的QTL,鉴别到一些与背膘厚关联的SNP以及少量候选基因。这些研究主要集中在资源群体和商业群体中,对我国特有的地方猪种的研究相对较少。本研究测量了316头莱芜猪和334头二花脸猪的肩部、胸部(第6至第7肋之间)、腰部和臀部的屠体背膘厚。在这两个群体中,四个部位的背膘厚均超过25毫米,其中肩部背膘最厚,腰部背膘最薄。这两个品种的背膘厚存在差异,莱芜猪各部位背膘均厚于二花脸猪相应部位的背膘。在这两品种中,性别对背膘厚的影响也不一样。性别对莱芜猪的背膘厚没有影响;而在二花脸群体中阉公猪的背膘显著厚于母猪的背膘。另外,还计算了背膘厚、板油重、花油重和腹脂重8个脂肪沉积性状之间的表型相关。结果显示这些性状之间均呈显著正相关,其中平均背膘与6-7肋膘厚的相关性最强,相关系数达0.9以上。接下来利用猪60K SNP芯片对这650个个体进行SNP分型,并进行单群体的全基因组关联分析(GWAS)以及荟萃分析(GWAS-meta)。在二花脸猪的4号和7号染色体上均检测到与背膘厚达到基因组或染色体水平(建议水平)显著关联的SNP。在莱芜猪的11号染色体上鉴别到1个与肩部膘厚关联达染色体水平的SNP;在12号染色体上检测到2个与胸部膘厚关联达染色体水平的SNP。GWAS meta分析结果显示,在4号、7号、12号和X号染色体上均检测到与背膘厚显著关联的SNP。Meta分析的检验效率比单群体的检验效率高。除11号染色体上的信号在Meta分析中消失外,其他的染色体上的关联在Meta分析中均可检测到,且在X染色体上鉴别到了一个与背膘厚显著关联的SNP。本研究在4号、7号11号、12号和X号染色体上发现的关联信号鉴证了前人的报道。为背膘厚的遗传解析及莱芜猪和二花脸猪背膘厚的选育提高奠定了基础。
[Abstract]:Backfat thickness is an indicator of fat deposition, and it is also an indicator of lean meat rate in production. Therefore, the genetic analysis of backfat thickness is of great economic value. Backfat thickness is greatly influenced by varieties, and there are significant differences between Chinese and Western pig species: large white, long white, Duroc and other lean meat pig breeds in the west, while Laiwu, two face, etc. Fat type pigs have thick back fat. With the development of molecular biotechnology and the emergence of 60K SNP chips, many domestic and foreign scholars have inherited the genetic analysis of backfat thickness of pigs, located a lot of QTL, and identified some SNP associated with backfat thickness and a small number of candidate genes. These studies are mainly concentrated in resource and commercial groups. The study of local pig species is relatively small in our country. This study measured the shoulders of 316 Laiwu pigs and 334 two face pigs, the chest (sixth to seventh ribs), the thick back fat of the waist and buttocks. In these two groups, the back fat of four parts was more than 25 mm. The back fat of the middle shoulder was the thickest and the back fat of the waist was the thinnest. These two varieties were two varieties. The back fat of all parts of the Laiwu pig was thicker than the back fat in the corresponding part of the two Hualian pig. In these two varieties, the effect of sex on backfat thickness was different. The sex had no effect on the backfat thickness of the Laiwu pig, but the back fat of the castrate was thicker than the back fat of the sow in the two flower face population. The results showed that the correlation between the average back fat and the 6-7 ribs thickness was the strongest, and the correlation coefficient was over 0.9. Then the 650 individuals were typed by the pig 60K SNP chip, and the whole genome of the single population was carried out. Combined analysis (GWAS) and meta-analysis (GWAS-meta). On chromosome 4 and chromosome 7 of the two Hualian pigs, a significant association with the back fat thickness to the genome or chromosome level (suggested level) was detected on chromosome 11 of the Laiwu pig on chromosome 11 of Laiwu pig to identify 1 SNP associated with the shoulder fat thickness associated with the chromosome level; and 2 on chromosome 12. The SNP.GWAS meta analysis, which was associated with the chromosome level of the chest fat thickness, showed that the efficiency of the SNP.Meta analysis that was significantly associated with the back fat thickness on chromosome 4, No. 7, 12 and X was higher than that of the single population. The correlation on other chromosomes except for the signal on chromosome 11 disappeared in Meta analysis. It was detected in the Meta analysis, and on the X chromosome, a SNP. related to the back fat thickness was identified. The related signals found on chromosome 4, No. 7, No. 11, No. 12 and X were identified by previous reports. The genetic analysis for back fat thickness and the breeding and raising of the back fat thickness of Laiwu pigs and two Hualian pigs lay the foundation.
【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S828

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