摘要：转录因子又称反式作用因子，能与顺式作用元件结合参与基因调控。Trihelix是最先被鉴定的一类转录因子家族，如今在植物中已发现60余种该基因家族。最早对他们的研究仅限于光应答调控方面，近些年随着生物技术的进一步发展，其在植物生长发育、抗逆境胁迫等方面的功能逐渐被发现。经聚类及结构域分析发现，Trihelix含强保守性三螺旋结构，我们通过分析结构域的不同，将其分为5个亚家族。同时针对染色体区段复制情况进行了一系列的分析，图示化结果发现，一些Trihelix 转录因子在同一植物及不同植物间分别存在着不同密度的种内及种间的染色体线性复制关系，因而相应地表现出不同程度的染色体区段同源性。借助已发表的水稻等基因组草图和数据，在本研究中，我们将水稻、二穗短柄草中的Trihelix转录因子家族进行了筛选。借助生物信息学软件分析了Trihelix转录因子家族在植物中存在的数目，并依据结构域特点的不同将其分为了五个亚家族，同时进行了系统发生学分析。该研究有助于我们全面了解植物Trihelix基因家族的分类和特点，对植物Trihelix基因的克隆、功能鉴定具有重要意义。78555

毕业论文关键词：水稻；二穗短柄草；Trihelix；转录因子家族；进化

Abstract: Transcription factor, also known as trans acting factor, which can bind to the promoter to play a role in gene-regulation。 The Trihelix transcription factor family is one of the family of transcription factors which were identified in the earliest, and 60 species have been found in the plant。 The earliest research is limited to the regulation of light response, and then its function in plant growth and development, and other aspects of stress resistance with the further development of biotechnology and bioinformatics is found。 Through this sequence clustering and functional domain analysis, we can find that Trihelix transcription factor family with conservative strong, special "helix loop helix loop helix" structure, according to the analysis of the structure characteristics and genetic distance between, which is pided into five subfamilies。 We also set a series of analysis for chromosomal replication, through the software chart analysis, we found that some Trihelix transcription factor in one plant and between different plants, there are different density within species and between species of the linear chromosome complex of relations, and accordingly showed different degrees of chromosome homology phenomenon。 In this study, the Trihelix transcription factors in plants were screened by the Trihelix transcription factor family, which was published by the rice genome and the data。 With the help of bioinformatics software we analysed the number of Trihelix family of transcription factors in plants , and on the basis of special structure characteristics of different we pided the gene-family into five subfamilies, and made the phylogenetic analysis and comparison。 This study has a comprehensive understanding of the kinds and characteristics of the plant Trihelix gene family, which has important significance for the cloning and functional identification of plant Trihelix gene。

Keywords: rice; Brachypodium distachyum;Trihelix; Transcription factor family; evolution

目录

1引言 6

1。1 转录因子的概念 6

1。2 Trihelix转录因子的来源 6

1。3 Trihelix转录因子的结构特点 6

1。4 Trihelix转录因子的功能 7

2 材料与方法 8

2。1 植物Trihelix转录因子数据获取与鉴定 8

2。2 Trihelix保守序列的鉴定和分析