草菇菌丝体与原基差异表达基因分析

Analysis of Differentially Expressed Genes between Mycelium and Primordium of Paddy Straw Mushroom(Volvariella volvacea)

采用Solexa测序技术,对草菇菌丝体和原基进行了数字基因表达谱(DGE)测序,在菌丝体和原基文库中分别得到5701781个和5659262个高质量测序标签(cleantags),对应的标签种数(distinct clean tags)分别为85626和95363。将所有高质量测序标签与参考基因库进行比对,在菌丝体和原基文库中,占标签种数的43.32%和52.57%的标签可以唯一定位(map)到参考序列上,占标签种数的21.65%和21.47%的标签可以被定位到基因组序列上。最终,被菌丝体和原基标签唯一定位的基因数(unambiguous tag-mapped genes)分别为14794和15534。差异基因分析显示,两个文库中共有显著性差异表达的基因4163个,其中在原基中上调、下调的基因数分别为2486和1677,只在原基中表达的基因321个。经过Blastnr比对,在原基中特异表达的基因,涉及蛋白质(氨基酸)合成与代谢、糖代谢、脂类代谢和抗逆反应等多个代谢途径。GO功能富集分析结果表明,葡萄糖、己糖和乙醇等代谢途径大部分基因下调表达。Pathway功能富集分析结果表明,合成核糖体蛋白的基因均下调表达,表明原基形成时细胞代谢减弱,蛋白质合成量减小。

The expression profiling of mycelium and primordium of Volvariella volvacea was analyzed by using high-throughput sequencing technology based on the Solexa Genome Analyzer platform.Totally 5 701 781 and 5 659 262 clean tags for mycelium and primordium libraries were obtained corresponding to 85 626 and 95 363 distinct clean tags respectively.Comparing all the clean tags with gene bank,in mycelium and primordium libraries,43.32% and 52.27% of the distinct clean tags were mapped unambiguously to the reference database respectively,and 21.65% and 21.74% of the distinct clean tags were mapped to the genome database of Volvariella volvacea.Finally,14 794 and 15 534 unambiguous tag-mapped genes were obtained.Analysis of differentially expressed genes shows that there are 4 163 genes differentially expressed between two libraries,and in the primordium library,2 486 of them are up-regulated while 1 677 of them are down-regulated.There are 321 genes that are only expressed in the primordium library.With Blastnr comparison,they are found to be related to protein and amino metabolism,glucose metabolism,lignin and cellulose degradation,lipid metabolism cytoskeleton,and so on.Gene ontology functional enrichment analysis reveals that most genes related to glucose metabolic process,monosaccharide catabolic process,hexose catabolic process,alcohol catabolic process,and glucose metabolic process are down-regulated.Pathway enrichment analysis shows that genes related to ribosome are all down-regulated,and this indicates that when primordium is developed the cell metabolism slows down and the protein synthesis decreases.