银杏细胞转录组高通量测序及分析

Sequencing and Analysis of the Transcriptome of Ginkgo biloba L.Cells

利用Illumina的Genome Analyzer IIx对银杏(Ginkgo Biloba)细胞转录组进行高通量测序,挖掘银杏内酯和紫杉醇生物合成基因,特别是新的羟基化酶基因,为今后最终完善红豆杉细胞紫杉醇生物合成途径中未知的羟基化步骤作准备。通过测序,获得了银杏细胞69 286个contig,56 387个scaffold,32 032个unigene。Unigene平均长度636bp。另外从gap分布、GC含量、基因组coverage等方面对unigene进行评估,数据显示测序质量好,可信度高。通过分析unigene的表达和功能注释等信息,发现66个属于CYP450基因家族,726个参与次生代谢物合成,其中59个与萜类合成有关,17个与二萜类合成相关。利用生物信息学方法从Michigan State University银杏成熟叶、侧根、成熟果实、无菌苗以及次生茎的转录组数据中找到了与银杏细胞CYP450高度同源的紫杉烷羟基化酶候选基因15个,为后续研究奠定了基础。

To sequence the transcriptome of Ginkgo biloba L. cells, Illumina Genome Analyzer IIx was used. One purpose is to discover candidate genes involved in ginkgolide biosynthesis and new hydroxylases in Ginkgo biloba cells such as taxoid 9-alpha hydroxylase, which will complete the unknown hydroxylation steps in taxol biosynthesis pathway in Taxus sp. A total of 69 286 contigs, 56 387 scaffolds and 32 032 unigenes with average length of 636bp were generated. Unigene qualities from several aspects like gap distribution, GC content, gene coverage were assessed. The results indicate that the sequencing data is good with high quality and reliability. Analyzed the information of unigene expression and functional annotation, we found that 66 unigenes belong to CYP450 gene family, 726 relate to secondary metabolism among which 59 involved in terpenoid metabolism and 17 involved in diterpenoid biosynthesis. At last, 15 hydroxylase candidates were selected by bioinformatics analysis our transcriptome data of Ginkgo biloba L. cells and the Michigan State University transcriptome data of Ginkgo biloba L. tissues. These candidate genes selection work set foundation for the further research.