Ko Kwan Soo, Jung Hack Sung
School of Biological Sciences, Seoul National University, San 56-1 Shinrim-dong, Kwanag-gu, Seoul 151-742, Republic of Korea.
Mol Phylogenet Evol. 2002 May;23(2):112-22. doi: 10.1016/S1055-7903(02)00009-X.
To explore phylogenetic relationships of Trichaptum species, internal transcribed spacer (ITS) regions of nuclear ribosomal DNAs were sequenced and analyzed. Gene trees from ITS1 and ITS2 sequences showed striking discrepancy in relationships of eight T. abietinum strains. All strains of T. abietinum had a single orthologous ITS2 type, but there were three paralogous types in the ITS1 region, which were designated Types I, II, and III. PCR amplification tests using type-specific primers showed that Types I and II are present in all strains of T. abietinum. The results suggest that gene duplication of the ancestral ITS1 region might have occurred prior to evolutionary radiation of Trichaptum and both types have been maintained in Trichaptum. However, Type III was amplified only in three T. abietinum strains collected from Korea, indicating that a new local geographic subtype has arisen in Korean strains.
为了探究拟层孔菌属物种的系统发育关系，对核糖体DNA的内部转录间隔区（ITS）进行了测序和分析。来自ITS1和ITS2序列的基因树在8株冷杉拟层孔菌的关系上显示出显著差异。所有冷杉拟层孔菌菌株都有单一的直系同源ITS2类型，但在ITS1区域有三种旁系同源类型，分别命名为I型、II型和III型。使用类型特异性引物的PCR扩增试验表明，I型和II型存在于所有冷杉拟层孔菌菌株中。结果表明，祖先ITS1区域的基因复制可能发生在拟层孔菌进化辐射之前，并且这两种类型在拟层孔菌中都得以保留。然而，III型仅在从韩国采集的3株冷杉拟层孔菌菌株中扩增出来，表明韩国菌株中出现了一种新的本地地理亚型。
