用cDNA微阵列技术快速筛选粗毛栓菌的表达基因(英文)

Rapid Screening of Expressed Genes of Trametes gallica by cDNA Microarray

利用cDNA微阵列技术快速筛选具有较强降解木质纤维素能力的白腐真菌粗毛栓菌 (Trametesgallica)的表达基因 .利用木质素生物降解模式菌株黄孢原毛平革菌 (Phanerochaetechrysosporium)的cDNA制备研究所用微阵列 .在含有2 5 96个cDNA片段的芯片上共检测到 172个阳性克隆 ,其中有 16 5个克隆的荧光信号比值 (Cy 5 /Cy 3)在 0 5和 2 0之间 ,占所检测阳性克隆数的 95 9% .对应于在限氮条件下生长 5天和 12天的粗毛栓菌培养物 ,分别有 3个和 4个时序特异性差异表达基因 .随机挑取 12 2个克隆进行测序和序列比对 ,发现所测序列中有 118个能够很好地定位于黄孢原毛平革菌的基因组上 .结果显示 ,粗毛栓菌与黄孢原毛平革菌在表达序列上存在较大差异 ,表明这两种真菌之间存在着较远的亲缘关系 .通过同源性比对分析 ,发现 2个令人感兴趣的克隆 ,一个对应于黄孢原毛平革菌过氧化物酶基因lpoB的部分片段 ,另一个为编码一种热激蛋白的基因 .

Effort was made to screen expressed genes of a white-rot fungus Trametes gallica by using cDNA microarray from Phanerochaete chrysosporium, a well known model strain used for studying lignin-degrading systems. The results showed that there were only 172 positive clones detected on the microarray and 95.9% of the clones had a ratio of Cy-5/Cy-3 from 0.5 to 2.0. However, only 3 and 4 clones with the Cy-5/Cy-3 ratio over 2.0 and lower than 0.5 respectively, were found, which are corresponding to 5- and 12-day cultures of T. gallica. One hundred and twenty-two clones were randomly selected and sequenced, of which 118 clones could be perfectly located in the genome of P. chrysosporium. The result indicates that there is obvious sequence difference between probes from T. gallica and inserts on the chip from P. chrysosporium, exhibiting far relative between these two fungi. Two interesting clones have been obtained from homology comparison, one corresponding to a fragment of peroxidase lpoB gene of P. chrysosporium and the other encoding a sort of heat shock protein.