[关键词]
[摘要]
为研究野生冬虫夏草的基因表达谱和挖掘其功能基因,在前期构建的冬虫夏草高质量cDNA文库基础上,挑选21845个克隆测序,筛选出了20136条EST序列,最终获得6434条非重复序列,包括2462条重叠群,3972条单一序列,代表本物种的转录序列。与GenBank中已知序列BLAST比对(E值10-5),获得部分同源基因的功能注释。基因功能分属7个不同的类别。本文重点讨论了营养物质消化吸收相关基因与抗性基因,旨在说明冬虫夏草菌适应寄生环境的机制,为进一步从分子水平研究活性成分及开发利用这一基因资源提供了条件。
[Key word]
[Abstract]
Two complementary DNA(cDNA) libraries were constructed from the tissues isolated from Cordyceps sinensis (Berk.) Sacc. Using single-pass sequencing of 21845 cDNA clones, 20136 expressed sequence tags(ESTs) were found to be assembled into 2462 contigs sequences and 3972 singletons representing 6434 putative transcripts. Via BLAST searches with a similarity cut off of E≤10-5, unigenes were annotated based upon matches in the NCBI nr. The BLASTX search revealed that 4028 ESTs had similarities with protein sequences available from databases; 350 of these ESTs were categorized according to their putative functions. Most ESTs were observed to function in primary metabolism, protein and RNA metabolism, cell structure, cell growth and division, protein destination and storage, transport and secretion, or signal transduction. The remaining ESTs with putative homologues were classified into 10 additional categories. These results indicate that EST may be a useful tool for investigating the functional genomics of this fungal.
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[基金项目]
国家中医药管理局资助项目(2000-J-P-56):冬虫夏草cDNA文库,蛋白质图谱的建立及功能基因的确定,负责人:金永三。