【作者】 张宇；

【导师】 王泽英； 豆兴堂；

【作者基本信息】 沈阳农业大学 ， 农业硕士（专业学位）， 2023， 硕士

【摘要】 辽宁绒山羊以遗传力稳定而闻名,是我国珍贵的物种资源,它产绒量大,绒纤维长,对纤维业和纺织业做出了巨大贡献,但是羊绒细度不够理想,随着人们对羊绒细度的追求越来越高,同时羊绒细度还是评定羊绒品质和价格的重要参考指标,因此降低羊绒细度是一个关键问题,那么寻找与羊绒细度相关的关键基因,并将其用于改善该表型的研究中就显得尤为重要。随着研究的不断深入,相关组学和测序技术在调控羊绒细度方面也随之向前发展,同时还发现翻译组学在识别与表型性状相关基因的研究中有着重要的意义。翻译组学是指对与核糖体结合的正在翻译的RNA片段进行测序,可以对正在进行翻译的基因进行精确定量,比较不同生理、病理条件下或不同处理下不同样本基因的翻译量变化。尽管做了这些努力,但从翻译组学角度筛选与羊绒细度相关的功能基因仍然是未知的,因此本研究从分子生物学角度出发,通过翻译组学方法筛选出与羊绒细度有关的功能基因及相关调控机制,为进一步改善羊绒品质提供理论基础,并为辽宁绒山羊遗传育种以及生产实践提供指导意义,我们根据试验分析和大量文献检索将COL6A5基因与产绒性能进行相关性研究。相关研究与获得结果如下:1.翻译组学筛选羊绒细度功能基因我们收集了(6只)辽宁绒山羊生长期皮肤样品,通过翻译组学核糖体印迹测序(Ribosome Profiling,Ribo-seq)方法对细型(3只)辽宁绒山羊(FT＿LCG)和粗型(3只)辽宁绒山羊(CT＿LCG)进行分析,得到FT＿LCG的Clean reads分别为50431480,50051017,51299342;CT＿LCG的Clean reads分别为47332796,51323088,59536550。共鉴定了27197个共表达基因,并发现有529个差异基因,其中上调343个,下调186个,而且对核糖体保护RNA片段(RPF)的长度进行了富集评估,发现RPF长度在22nt时富集频率最高,在对差异基因进行GO富集分析和KEGG富集分析中发现主要在细胞外区域发挥功能,富集的通路大多数在人乳头瘤病毒感染通路,由差异基因分析将COL6A5基因作为辽宁绒山羊羊绒细度研究的关键基因。2.羊绒细度关键基因COL6A5与产绒性能相关性研究本研究通过对羊绒细度候选基因COL6A5进行单核苷酸多态性(SNP)分析后发现该基因有3个突变位点,分别为G50985A,G51140T,G51175A,从不同位点的遗传多态性,基因替代效应对COL6A5基因与羊绒细度及产绒性能进行相关性分析,还将单倍型组合与产绒性能进行了相关性研究,结果发现3个位点的自然长度,细度,净绒率,有效纤维数以及产绒量的差异均不显著,说明在该群体中羊绒细度均值基本保持接近,但是G50985A位点AG基因型,G51140T位点GT基因型,G51175A位点AA基因型,单倍型组合H1H5:AGGGAG,H4H4:GGGGAA的产绒性状指标相对较优,该基因可作为绒山羊产绒性能的遗传辅助标记。更多还原

【Abstract】 Liaoning Cashmere Goat is famous for its stable heritability.It is a precious species resource in China.It produces a large amount of cashmere and has long cashmere fiber,which has made great contributions to the fiber industry and textile industry.However,the cashmere fineness is not ideal.With people’s pursuit of cashmere fineness becoming higher and higher,and cashmere fineness is also an important reference index to evaluate the quality and price of cashmere,so reducing cashmere fineness is a key issue,So it is particularly important to find the key genes related to cashmere fineness and use them to improve the phenotype.With the continuous deepening of research,the related genomics and sequencing technology have also developed in the control of cashmere fineness.At the same time,it is also found that translatomics has important significance in the identification of genes related to phenotypic traits.Translatomics refers to sequencing the RNA fragments being translated combined with ribosomes,which can accurately quantify the genes being translated,and compare the translation changes of different sample genes under different physiological and pathological conditions or different treatments.Despite these efforts,it is still unknown to screen the functional genes related to cashmere fineness from the perspective of translatomics.Therefore,from the perspective of molecular biology,this study intends to screen the functional genes related to cashmere fineness and related regulatory mechanisms through translatomics,providing a theoretical basis for further improving cashmere quality and guiding significance for genetic breeding and production practice of Liaoning cashmere goat.Based on experimental analysis and extensive literature search,we conducted a correlation study between the COL6A5 gene and cashmere production performance.Relevant studies and results are as follows:1.Selection of functional genes of cashmere fineness by translatomicsWe collected the growing period skin samples from six Liaoning cashmere goats and analyzed the fine(three)Liaoning cashmere goats(FT＿LCG)and coarse(three)Liaoning cashmere goats(CT＿LCG)by translatomics ribosome profiling(Ribo-seq).The clean reads of FT＿LCG were 50431480,50051017,51299342 respectively;The clean reads of CT＿LCG were 47332796,51323088,59536550 respectively.A total of 27197 co expressed genes were identified,and 529 differential genes were found,including 343 up-regulated and 186down-regulated.The enrichment evaluation of the length of ribosome protected RNA fragment(RPF)showed that the enrichment frequency was the highest when the RPF length was 22 nt.In the GO enrichment analysis and KEGG enrichment analysis of differential genes,it was found that they mainly function in the extracellular region,and most of the enrichment pathways are in the human papillomavirus infection pathway,the COL6A5 gene was identified as a key gene in the study of cashmere fineness in Liaoning cashmere goat through differential gene analysis.2.Correlation analysis between cashmere fineness key gene COL6A5 and cashmere production performanceIn this study,through the single nucleotide polymorphism(SNP)analysis of cashmere fineness candidate gene COL6A5,it was found that the gene has three mutation sites,namely G50985 A,G51140T and G51175 A.The correlation between COL6A5 gene and cashmere fineness and cashmere production performance was analyzed from the genetic polymorphism and gene substitution effect of different loci,and the correlation between haplotype combination and cashmere production performance was also analyzed.The results showed that there were no significant differences in natural length,fineness,net cashmere rate,number of effective fibers and cashmere yield among the three loci,indicating that the mean value of cashmere fineness remained close in this population.However,the AG genotype at G50985 A locus,GT genotype at G51140 T locus,AA genotype at G51175 A locus and haplotype combination H1H5: AGGGAG and H4H4: GGGGAA have relatively good cashmere production traits,this gene can serve as a genetic auxiliary marker for cashmere production performance in cashmere goat.更多还原