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随着国际上转录组数据及本室22周孕龄人胎肝表达序列标签数据的不断增加,先前该组织表达谱的研究有必要进行更新与完善.本研究首先将22周孕龄人胎肝每一表达序列标签与自身数据库,UniGene,DoTS,MGC以及Twinscan预测的人类转录组数据库进行比对以归类.然后,经过电子拼接和基因鉴定,对已知基因进行GO(gene ontology)分类,对未知基因进行Pfam和ScanProsite功能预测.最后,对人胎肝、成人肝、骨髓、胸腺及淋巴结这些拥有造血作用或可表明人胎肝特性的5种组织进行了层次聚类分析.结果表明:(ⅰ)与5种最新人类转录组数据库比对,极大地降低了那些属于一个基因但互不交叠的序列被划分到不同簇的可能性,因此在进行EST归类时,推荐与互联网上有关最新数据进行比对;(ⅱ)一些先前未知EST已被鉴定为已知基因,1379个EST被鉴定为本室独有的全新序列;(ⅲ)通过GO分类,对22周孕龄人胎肝有了一个大致了解,同时获得了6个细胞迁移基因和6个造血相关基因;(ⅳ)通过基因功能预测获得了277个模体(profile),其中有5个类型可分布于10个以上基因之中;(ⅴ)层次聚类表明,5种组织关系与它们的功能相一致;(ⅵ)建立了世界上最大的22周孕龄人胎肝表达序列标签数据库.总之,22周孕龄人胎肝表达序列标签数据的更新与初步分析将有助于对人胎肝造血机制及细胞迁移机制的了解,可促进未来对该组织进行全面深入的研究。
With the continuous increase of transcriptome data and sequence tag data of fetal liver in 22 weeks of pregnancy in our country, previous research on the expression profile of this tissue needs to be updated and perfected.In this study, Each expressed sequence tag was compared with its own database, UniGene, DoTS, MGC, and Twinscan human transcriptome database for classification.After the electronic splicing and gene identification, GO (gene ontology) classification of known genes, Pfam and ScanProsite function prediction of unknown genes.Finally, the hierarchical clustering analysis of five kinds of tissues which have hematopoiesis or human fetal liver characteristics, such as human fetal liver, adult liver, bone marrow, thymus and lymph nodes, (I) alignments with the five most recent human transcriptome databases, greatly reducing the likelihood that sequences that belong to one gene but do not overlap are grouped into different clusters, so EST classification is recommended for use on the Internet (Ii) some of the previously unknown ESTs have been identified as known genes and 1379 ESTs have been identified as unique new sequences in this locality; (iii) by GO classification, 22 weeks of gestational age There was a general understanding of human fetal liver and at the same time 6 cellular migratory genes and 6 hematopoietic related genes were obtained; (iv) 277 profiles were obtained by genetic function prediction, of which 5 were distributed in 10 (Iv) Hierarchical clustering indicates that the five tissue relationships are consistent with their function (iv) Established the world’s largest database of 22-week gestational human fetal liver expression sequence tags. In summary, at 22 weeks Updating and preliminary analysis of sequence tagging data for gestational age human fetal liver will contribute to understanding human fetal liver hematopoietic mechanisms and cell migration mechanisms and may facilitate a comprehensive and in-depth study of the organization in the future.