人类性染色体DNA回文序列分析

发布时间：2018-05-12 21:55

本文选题：Y染色体 + X染色体　；参考：《兰州大学》2011年硕士论文

【摘要】：为了研究基因突变、基因转变和同源重组对Y染色体的影响。我们利用分子生物学软件对人类和黑猩猩Y染色体各类序列进行了详细全面的比对,由各类序列的比对结果之间做两两对照,我们得出回文中基因转变对突变的修复呈中性以及过多的重复序列之间的同源重组会对Y色体造成损害的结论。我们定义回文破缺率是单个碱基突变率与平均回文碱基修复率之差,由此给出了平均回文碱基修复率与同源序列同源性和回文臂与臂一致性的关系。而同源序列同源性和回文臂与臂一致性都是可以通过序列比对得到,于是得出了平均回文碱基修复率的具体数值。 DNA回文序列是一种常见的特殊DNA结构,它具有旋转对称性。本文通过分子生物学软件对人类Y染色体Pl-P8八条DNA回文序列、人类X染色体上的二十条DNA回文序列和黑猩猩Y染色体上的十六条DNA回文序列进行比对,利用回文旋转对称性,寻找和统计了这些回文序列中对称性突变的具体位点及破缺碱基的具体信息。通过分析统计结果,发现回文序列中的破缺更容易发生在简单序列重复区域且破缺多发生在化学结构上的相似的嘧啶与嘧啶之间和嘌呤与嘌呤之间,另外还发现转换突变与颠换突变的比值与突变碱基紧邻的G+C含量成正相关。
[Abstract]:In order to study the effect of gene mutation, gene transformation and homologous recombination on Y chromosome. We made a detailed and comprehensive alignment between human and chimpanzee Y chromosome sequences by using molecular biology software. We conclude that the gene transformation in palindromes is neutral to the repair of mutation and that the homologous recombination of too many repeat sequences will damage the Y chromophore. We define the palindrome breaking rate as the difference between the single base mutation rate and the average palindrome repair rate. The relationship between the average palindrome repair rate and the homology between palindromes and the coherence between palindromes and palindromes is given. The homology of homologous sequences and the coherence of palindromes and arms can be obtained by sequence alignment, so the specific value of average palindrome repair rate is obtained. DNA palindromes are a common special DNA structure with rotational symmetry. Eight DNA palindromes on human Y chromosome, 20 DNA palindromes on human X chromosome and 16 DNA palindromes on chimpanzee Y chromosome were compared by molecular biology software. The specific sites of symmetry mutation and the specific information of breaking bases in these palindromes were found and counted. By analyzing the statistical results, it was found that the cleavage of palindromes was more likely to occur in the repeated regions of simple sequences and that the breaks occurred more frequently between pyrimidine and between purine and purine, which were similar in chemical structure. It was also found that the ratio of transition mutation to transversion mutation was positively correlated with the content of G C adjacent to the base of the mutation.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R346

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