基于比较基因组学方法的丝状子囊菌同源序列分析

为探讨丝状子囊菌基因组的同源保守序列作为标记基因,利用Standalone BLASTN方法将构巢曲霉全基因组基因分别与30种丝状子囊菌基因组比较.构巢曲霉与每个丝状子囊菌基因组之间的同源匹配基因数量似乎可反映子囊菌之间的进化关系,构巢曲霉（10,560个基因）与15种散囊菌纲其他真菌间的匹配基因数量为5,179-7,747个,其中与另外7个同属的种匹配的基因数量为7,434-7,747个,而与亲缘关系较远的2种锤舌菌纲真菌灰葡萄孢和核盘菌的匹配基因数量分别仅有4,318个和4,242个.构巢曲霉的10,560个基因与20余种子囊菌基因组同时匹配的基因数为3,509个,占33.2％,构巢曲霉基因与30种子囊菌共同匹配的基因仅924个.此外,E值大小在10-30_0.1范围的同源序列变异性大,而在0-10-100范围的同源序列高度保守.随着基因组序列数据的增加,比较基因组方法将会在真菌系统学研究领域发挥更大的作用.

Investigation of homologous sequences in filamentous ascomycetes based on comparative genomics

To investigate conserved homologs of filamentous ascomycete genomes as marker genes, the complete gene set of Aspergillus nidulans was compared against 30 other genomes of filamentous ascomycetes separately using Standalone BLASTN. The number of matches between A. nidulans and each genome seemed to reflect the evolutionary relationships. The comparison of the A. nidulans genome (10,560 genes) against 15 other Eurotiomycetes showed the number of pairwise matching homologs ranged from 5,179 to 7,747, while matches between A. nidulans and seven other Aspergillus species ranged from 7,434 to 7,747. The matches between A. nidulans and two more distantly related species, Botrytis cinerea and Sclerotinia sclerotiorum (Leotiomycetes), were 4,318 and 4,242, respectively. Of 10,560 genes in A. nidulans, the total number of matches found in common in over 20 other filamentous ascomycete genomes was 3,509, accounting for over 33% of all the genes, of which 924 genes were found in all 30 other filamentous ascomycetes tested. Furthermore, the homologous sequences at E-values in the ranges of 10-30 to 0.1 showed greater polymorphisms, while those at E-values of 0 to 10-100 were highly conserved. With increasing genome sequence data, comparative genomics will play an increasing important role in fungal systematics.