绵羊TYRP基因快速进化以适应海拔变化
发布时间：2018-11-23 21:01
【摘要】：为研究高海拔绵羊群体强紫外线辐射适应性的分子机制,为绵羊群体间毛色多样性形成机制研究提供理论参考。本研究以分布于不同海拔高度的绵羊群体:高原型藏羊、欧拉型藏羊、山谷型藏羊、乌珠穆沁羊、苏尼特羊、滩羊、广灵大尾羊、小尾寒羊和湖羊作为试验材料,选择与黑色素合成相关的光保护基因TYRP1和TYRP2,采用混合样测序技术检测绵羊群体内这两个基因的SNP位点,采用直接测序的方法对其进行分型,并对这些位点的基因频率及基因的单倍型频率与海拔高度进行关联分析;同时对12个物种的TYRP1和TYRP2基因系统发生关系、基因相似性和选择方向进行系统分析,并且用Lositan软件对9个绵羊群体内检测到的TYRP基因的SNP位点进行受选择状况分析;利用生物信息学的方法对TYRP蛋白的结构进行预测分析,分析TYRP基因变异位点和TYRP蛋白结构的关系,进一步阐述TYRP的基因结构与其蛋白质功能之间的关系,为中国绵羊的选育工作和遗传资源保护利用提供理论参考。研究结果如下:1.混合样测序在绵羊群体内TYRP基因中共检测到35个SNP位点,其中TYRP1基因检测到21个位点,TYRP2基因中检测到14个位点。对这些位点的等位基因频率与各绵羊群体所在海拔高度进行关联分析发现,TYRP1基因中有5个SNP位点的等位基因频率和海拔高度显著相关,分别是g.11121CT、g.11124TC、g.26549CG、g.26682CT和g.26730CA,其中g.26682CT位点所在密码子编码的氨基酸为绵羊TYRP1蛋白磷酸化位点,g.26730CA位点所在密码子编码的氨基酸位于绵羊TYRP1蛋白的跨膜区域,g.11121CT位点的等位基因频率在高海拔群体分别与中低海拔两个绵羊群体间差异显著,同时在TYRP1基因中还有3个单倍型频率与海拔高度显著相关;TYRP2基因中没有检测到与海拔变化显著相关的变异。由此推测,TYRP1基因的变异在绵羊毛色形成中可能发挥着重要的作用。2.对绵羊TYRP基因编码的蛋白的生物信息学预测分析得到,绵羊TYRP1基因编码537个氨基酸,1-24位氨基酸区间为信号肽区域,跨膜区域有两段,分别是7-24和479-501,磷酸化位点有27个,二级结构预测结果显示其螺旋结构(Helix)占14.71%,延链(Strand)占5.59%,环状结构(Loop)占79.70%,86-465位氨基酸为TYRP1蛋白的功能域;绵羊TYRP2基因编码517个氨基酸,1-23位氨基酸区间为信号肽区域,跨膜区域为469-491,磷酸化位点有23个,二级结构预测结果显示其螺旋结构占17.02%,延链结构占3.48%,环状结构占79.50%,82-456位氨基酸为TYRP2蛋白的功能域。TYRP1和TYRP2蛋白的结构具有很高的相似性。3.TYRP基因在12个物种间正选择检验发现,TYRP1基因受到显著的正选择作用,TYRP2基因主要受到纯化选择的作用。9个绵羊群体间35个SNP位点正选择检验结果显示,TYRP1基因中有5个SNP位点受到正选择作用,一个位点受到平衡选择。正选择位点分别是g.10941CG、g.11055CG、g.11168CA、g.26717CT和g.26790AC,其中g.10941CG位点所在密码子编码的氨基酸位于TYRP1蛋白的信号肽区域,g.26717CT位点所在密码子编码的氨基酸在绵羊TYRP1蛋白的跨膜区域,g.11055CG位点所在的密码子编码的氨基酸位于绵羊TYRP1蛋白氨基酸序列的第46位,该氨基酸位点在物种间基因选择方向检验结果中同样受到显著的正选择作用,两者检测的结果相一致;TYRP2基因中检测到3个位点受到平衡选择的作用,分别是g.28506CA、g.28629CT和g.40404AC,其中g.28629CT位点所在密码子编码的氨基酸位于绵羊TYRP2蛋白的功能域,g.40404AC位点所在密码子编码的氨基酸为绵羊TYRP2蛋白的跨膜区域。由此可以推测,TYRP1基因受到的正选择作用和TYRP2基因受到的平衡选择的作用在绵羊群体适应不同海拔高度的不同紫外线辐射强度的环境中可能发挥着重要作用。
[Abstract]:In order to study the molecular mechanism of the adaptability of the high-altitude sheep population to the strong ultraviolet radiation, a theoretical reference is provided for the study of the formation mechanism of the wool-color diversity among the sheep. The research is to distribute the sheep group with different altitude: the plateau-type Tibetan sheep, the Euler-type Tibetan sheep, the valley-type Tibetan sheep, the black-pearl-muqin sheep, the Suits sheep, the beach sheep, the wide-and-long-tailed sheep, the small-tail cold sheep and the lake sheep as the test materials, selecting the light protection genes TYRP1 and TYRP2 related to the synthesis of melanin, detecting the SNP sites of the two genes in the sheep population by adopting a mixed sample sequencing technology, and typing the SNP sites of the two genes in the sheep population by adopting a direct sequencing method, and carrying out the correlation analysis on the gene frequency and the single-fold frequency of the gene and the altitude of the genes, and simultaneously carrying out system analysis on the relationship between the TYRP1 and TYRP2 gene systems of the 12 species, the gene similarity and the selection direction, and the structure of the TYP protein is predicted and analyzed by using the bioinformatics method, the relationship between the TYP gene mutation site and the TYP protein structure is analyzed, The relationship between the gene structure and its protein function of TYP is further elaborated, which provides a theoretical reference for the breeding of Chinese sheep and the protection of genetic resources. The results of the study are as follows: 1. A total of 35 SNP sites were detected in the TYP gene in the sheep population by the hybrid-like sequencing, of which the TYRP1 gene was detected at 21 sites and 14 sites were detected in the TYRP2 gene. The allele frequency of these sites was correlated with the altitude of each sheep population, and the allele frequency and altitude of the five SNP loci in the TYRP1 gene were significantly related, g. 11121CT, g. 11124TC, g. 26549CG, g. 26682CT and g. 26730CA, respectively. wherein the amino acid encoded by the codon of the g. 26682CT site is the phosphorylation site of the sheep TYRP1 protein, the amino acid encoded by the codon at the position where the g. 26730CA site is located is located in the transmembrane region of the sheep TYRP1 protein, There were also 3 single-fold frequencies in the TYRP1 gene that were significantly related to the altitude; there was no variation in the TYRP2 gene that was significantly related to altitude change. It is suggested that the variation of the TYRP1 gene may play an important role in the formation of the color of the wool. The bioinformatics prediction of the protein encoded by the sheep TYP gene is obtained, 537 amino acids are encoded by the sheep TYRP1 gene, the 1-24 position amino acid interval is a signal peptide region, two sections of the transmembrane region are respectively 7-24 and 479-501, and the phosphorylation sites are 27, The results of the two-stage structure show that the helix structure (Helix) is 14.71%, the strand (Strand) is 5.59%, the loop structure (Loop) is 77.9%, the 86-465 amino acid is the functional domain of the TYRP1 protein, the sheep TYRP2 gene encodes 517 amino acids, the 1-23 position amino acid interval is the signal peptide area, the transmembrane region is 469-491, The results of the two-stage structure prediction showed that the helical structure was 17. 02%, the structure of the extension chain was 3.48%, the ring-like structure was 70.50%, and the 82-456-position amino acid was the functional domain of the TYRP2 protein. TYRP1 and TYRP2 protein have a very high similarity. Five SNP sites in the TYRP1 gene are under positive selection and one site is balanced. The positive selection sites are g. 10941CG, g. 11055CG, g. 11168CA, g. 26717CT and g. 26790AC, wherein the amino acid encoded by the codon of the g. 10941CG site is located in the signal peptide region of the TYRP1 protein, the amino acid encoded by the codon at which the g. 26717CT site is located is in the transmembrane region of the sheep TYRP1 protein, g. the amino acid encoded by the codon at which the 11055CG site is located is located at the 46th position of the amino acid sequence of the sheep TYRP1 protein, and the amino acid site is also subjected to a significant positive selection effect in the test result of the inter-species gene selection direction, and the result of the two detection is consistent; The three sites detected in the TYRP2 gene were selected by the balance selection, g. 28506CA, g. 28629CT and g. 40404AC, where g. 28629CT site's codon-encoded amino acid is located in the functional domain of the sheep TYRP2 protein, and the amino acid encoded by the codon of the g. 40404AC site is the transmembrane region of the sheep TYRP2 protein. It is thus possible to speculate that the positive selection action of the TYRP1 gene and the effect of the balanced selection of the TYRP2 gene play an important role in the environment where the sheep population is adapted to different ultraviolet radiation intensity at different altitudes.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S826
本文编号：2352685
[Abstract]:In order to study the molecular mechanism of the adaptability of the high-altitude sheep population to the strong ultraviolet radiation, a theoretical reference is provided for the study of the formation mechanism of the wool-color diversity among the sheep. The research is to distribute the sheep group with different altitude: the plateau-type Tibetan sheep, the Euler-type Tibetan sheep, the valley-type Tibetan sheep, the black-pearl-muqin sheep, the Suits sheep, the beach sheep, the wide-and-long-tailed sheep, the small-tail cold sheep and the lake sheep as the test materials, selecting the light protection genes TYRP1 and TYRP2 related to the synthesis of melanin, detecting the SNP sites of the two genes in the sheep population by adopting a mixed sample sequencing technology, and typing the SNP sites of the two genes in the sheep population by adopting a direct sequencing method, and carrying out the correlation analysis on the gene frequency and the single-fold frequency of the gene and the altitude of the genes, and simultaneously carrying out system analysis on the relationship between the TYRP1 and TYRP2 gene systems of the 12 species, the gene similarity and the selection direction, and the structure of the TYP protein is predicted and analyzed by using the bioinformatics method, the relationship between the TYP gene mutation site and the TYP protein structure is analyzed, The relationship between the gene structure and its protein function of TYP is further elaborated, which provides a theoretical reference for the breeding of Chinese sheep and the protection of genetic resources. The results of the study are as follows: 1. A total of 35 SNP sites were detected in the TYP gene in the sheep population by the hybrid-like sequencing, of which the TYRP1 gene was detected at 21 sites and 14 sites were detected in the TYRP2 gene. The allele frequency of these sites was correlated with the altitude of each sheep population, and the allele frequency and altitude of the five SNP loci in the TYRP1 gene were significantly related, g. 11121CT, g. 11124TC, g. 26549CG, g. 26682CT and g. 26730CA, respectively. wherein the amino acid encoded by the codon of the g. 26682CT site is the phosphorylation site of the sheep TYRP1 protein, the amino acid encoded by the codon at the position where the g. 26730CA site is located is located in the transmembrane region of the sheep TYRP1 protein, There were also 3 single-fold frequencies in the TYRP1 gene that were significantly related to the altitude; there was no variation in the TYRP2 gene that was significantly related to altitude change. It is suggested that the variation of the TYRP1 gene may play an important role in the formation of the color of the wool. The bioinformatics prediction of the protein encoded by the sheep TYP gene is obtained, 537 amino acids are encoded by the sheep TYRP1 gene, the 1-24 position amino acid interval is a signal peptide region, two sections of the transmembrane region are respectively 7-24 and 479-501, and the phosphorylation sites are 27, The results of the two-stage structure show that the helix structure (Helix) is 14.71%, the strand (Strand) is 5.59%, the loop structure (Loop) is 77.9%, the 86-465 amino acid is the functional domain of the TYRP1 protein, the sheep TYRP2 gene encodes 517 amino acids, the 1-23 position amino acid interval is the signal peptide area, the transmembrane region is 469-491, The results of the two-stage structure prediction showed that the helical structure was 17. 02%, the structure of the extension chain was 3.48%, the ring-like structure was 70.50%, and the 82-456-position amino acid was the functional domain of the TYRP2 protein. TYRP1 and TYRP2 protein have a very high similarity. Five SNP sites in the TYRP1 gene are under positive selection and one site is balanced. The positive selection sites are g. 10941CG, g. 11055CG, g. 11168CA, g. 26717CT and g. 26790AC, wherein the amino acid encoded by the codon of the g. 10941CG site is located in the signal peptide region of the TYRP1 protein, the amino acid encoded by the codon at which the g. 26717CT site is located is in the transmembrane region of the sheep TYRP1 protein, g. the amino acid encoded by the codon at which the 11055CG site is located is located at the 46th position of the amino acid sequence of the sheep TYRP1 protein, and the amino acid site is also subjected to a significant positive selection effect in the test result of the inter-species gene selection direction, and the result of the two detection is consistent; The three sites detected in the TYRP2 gene were selected by the balance selection, g. 28506CA, g. 28629CT and g. 40404AC, where g. 28629CT site's codon-encoded amino acid is located in the functional domain of the sheep TYRP2 protein, and the amino acid encoded by the codon of the g. 40404AC site is the transmembrane region of the sheep TYRP2 protein. It is thus possible to speculate that the positive selection action of the TYRP1 gene and the effect of the balanced selection of the TYRP2 gene play an important role in the environment where the sheep population is adapted to different ultraviolet radiation intensity at different altitudes.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S826
【参考文献】
相关期刊论文 前1条
1 张琳西,王臻,郭树忠,夏炜,李巍;中波紫外线对体外培养的人黑色素细胞的影响[J];中国美容医学;2001年03期
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