猪IGF1R、RasGRP1及InsR基因候选功能突变位点效应研究

发布时间：2018-04-15 13:53

本文选题：猪 + 选择信号　；参考：《华中农业大学》2017年硕士论文

【摘要】：我国作为第一养猪大国,猪肉类产品占我国肉类消费的65%左右。养猪业是我国畜牧业发展的重点,但目前我国养猪经济效益还有待改善。我国地方猪与西方猪之间经济性状有着较大差异。西方猪由于长期的人工选择使得猪的经济性能不断提高,而中国地方猪由于选择的目的不同且选择的强度较弱,目前在瘦肉率、生长速度等重要的经济性状上与西方猪还存在较大的差距。人工选择的不同是中国地方猪与西方猪的经济性状产生较大差异的原因。本研究首先利用高通量测序数据对中西方猪种的选择信号差异进行了分析,筛选中西方猪种中受到强烈选择的基因,结果显示IGF1R、Ras GRP1及Ins R基因在中西方猪种中受到强烈选择,然后对等位基因差异表达情况进行了研究并进行了位点保守性分析,预测出关键的功能调控位点进行后续的分子水平研究及群体研究,以期望找到对猪进行品种改良的关键分子标记。本研究得到的主要结果如下:(1)通过选择信号分析发现IGF1R、Ras GRP1及Ins R基因在中西方猪种中受到强烈选择,并通过等位基因差异表达研究和物种保守性分析找到3个很可能影响基因表达的候选功能位点。(2)凝胶迁移实验结果发现转录因子YY1能够结合IGF1R基因-61K A/G多态位点,且对等位基因G有更强的结合能力。双荧光素酶报告基因系统活性检测证明该位点能够促进下游基因表达,且G等位基因发挥的作用更强。然后通过RNA干扰实验发现转录因子YY1表达降低能够抑制IGF1R的表达。(3)凝胶迁移实验结果显示转录因子Myo D能够结合IGF1R基因Intron20 G/A多态位点,且对G等位基因有更强的结合能力。然后通过荧光定量PCR发现小鼠骨骼肌卫星细胞分化后IGF1R和Myo D的表达量都着极显著的升高。(4)对IGF1R基因-61K A/G多态与杜洛克×二花脸F2群体免疫及生长性状进行关联分析,结果表明该位点与33日龄嗜酸性粒细胞比率极显著关联(p0.01),与80日龄体重显著关联(p0.05),可以作为对猪生长及免疫性状改良的候选分子标记。(5)对IGF1R基因Intron20 G/A多态与杜洛克×二花脸F2群体免疫及生长性状进行关联分析,结果表明该位点与33日龄嗜酸性粒细胞比率及80日龄体重都显著关联(p0.05),可以作为对猪生长及免疫性状改良的候选分子标记。(6)对RasGRP1基因+1K A/G多态与杜洛克×二花脸F2群体免疫及生长性状进行关联分析,结果表明该位点与80日龄体重显著关联(p0.05),可以作为对猪生长性状改良的候选分子标记。
[Abstract]:As the largest pig-raising country in China, pork products account for about 65% of our meat consumption.Pig raising industry is the focus of animal husbandry development in China, but the economic benefit of pig raising in China needs to be improved at present.There are great differences in economic characters between local pigs and western pigs in China.Western pigs have improved their economic performance as a result of long-term artificial selection, while local Chinese pigs are currently in lean meat ratio because of their different purposes and weak selection intensity.There is still a big gap between the growth rate and other important economic traits compared with the western pigs.The difference of artificial selection is the reason for the difference of economic characters between Chinese local pigs and western pigs.In this study, high throughput sequencing data were used to analyze the difference of selection signal between Chinese and Western pig breeds. The results showed that the IGF1RN Ras GRP1 and Ins R genes were strongly selected in Chinese and Western pig breeds.Then the allelic differential expression was studied and the locus conserved analysis was carried out to predict the key functional regulatory sites for further molecular level and population studies.We hope to find the key molecular markers for the improvement of pig breeds.The main results obtained in this study are as follows: (1) through the selection signal analysis, it was found that IGF1RN Ras GRP1 and Ins R genes were strongly selected in Chinese and Western pig breeds.Through allelic differential expression study and species conservation analysis, we found three candidate functional sites that may affect gene expression. The results showed that the transcription factor YY1 could bind to the IGF1R gene -61K A / G polymorphic sites, and the results showed that the transcriptional factor YY1 could bind to the IGF1R gene -61K A / G polymorphic loci.And the allele G has stronger binding ability.The detection of the activity of double luciferase reporter gene system showed that this locus could promote downstream gene expression and G allele played a more important role.Then RNA interference assay showed that the reduced expression of transcription factor YY1 could inhibit the expression of IGF1R. The result of gel migration experiment showed that Myo D could bind to Intron20 G / A polymorphic site of IGF1R gene and had stronger binding ability to G allele.Then fluorescence quantitative PCR showed that the expression of IGF1R and Myo D in mouse skeletal muscle satellite cells were significantly increased after differentiation.) the association analysis between IGF1R gene -61K A / G polymorphism and Duroc 脳 Erhualian F2 population immune and growth traits was carried out.The results showed that this locus was significantly associated with the ratio of eosinophils at 33 days old and weight at 80 days old, and could be used as a candidate molecular marker for the improvement of growth and immune traits of pigs. It could be used as a candidate molecular marker for IGF1R gene Intron20 G / A polymorphism and Duroc gene polymorphism.Ke 脳 Erhualian F2 population immunity and growth traits were analyzed by association analysis.The results showed that this locus was significantly associated with the ratio of eosinophils at 33 days old and body weight at 80 days old, and could be used as a candidate molecular marker for the improvement of growth and immune traits of pigs. It could be used as a candidate molecular marker for RasGRP1 gene 1K A / G polymorphism and Duroc 脳 diflorescence.The immune and growth traits of face F2 population were analyzed by association analysis.The results showed that this locus was significantly associated with body weight at 80 days old and could be used as a candidate molecular marker for improving pig growth traits.
【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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