台灣輪生細胞黏菌分子類緣關係研究

Abstract

摘要 將台灣各地及金門地區森林土壤中所採集分離而得的26個純培養菌株，併以日本地區4 種輪生細胞黏菌，抽取基因體DNA, 以適當引子，利用PCR反應及DNA序列得到rDNA ITS1-5.8S-ITS2 區域之分子序列。引用NCBI網站之GenBank登錄之3種輪生細胞黏菌之ITS1-5.8S-ITS2 區域之分子序列，經排序後，以Mega2，PAUP 4.0等軟體分析，建構出親緣關係樹。結果紫色輪生細胞黏菌（P. violaceum）和其他菌株之輪生細胞黏菌序列差異甚大，難以排序。引用GenBank中5種網柱細胞黏菌（Dictyostelium），以5.8S序列排序，發現Polysphondylium violaceum親緣關係較接近網柱細胞黏菌（Dictyostelium），不和其他輪生細胞黏菌形成一單系群。另以GenBank登錄之9種網柱細胞黏菌及3種輪生細胞黏菌之rDNA 部分18S序列做分析，亦得到相同結論。去除P. violaceum後之其他輪生細胞黏菌，以ITS1-5.8S-ITS2序列做分析，發現純白輪生細胞黏菌（P. candidum）和偽純白輪生細胞黏菌（P. pseudocandidum）親緣關係非常接近，可能同屬一種。而台灣各地所採得之透明輪生細胞黏菌（P. pallidum）並和其類似八個種類，經形態特徵及rDNA分子序列的比對，應為新種。

Abstract Twenty-six polysphondylid strains isolated from forest soils of Taiwan and Ginmen county, together with four polysphondylid strains from Japan were used in this study. Genomic DNA were extracted from these pure cultures, then the ITS and 5.8S rDNA were amplified by polymerase chain rection (PCR). The rDNA sequences of the tested isolates and three rDNA sequences of polysphondylid registered in NCBI were analyzed. Sequences were aligned by Clustal X, and the phylogenetic relationship tree was constructed by MEGA2 and PAUP 4.0 softwere. The results were shown as follows: In 5.8S and 18S sequences analysis, the phylogenetic relationship of P. violaceum was closer to Dictylstelium than the other Polysphondylium. In ITS and 5.8S rDNA sequences of Polysphondylium , P. candidum and P. pseudocandidum were so close that they may be concluded as the same species. The other isolates of Polysphondylium collected in Taiwan were identified as P. pallidum and different eight species. Base on morphological studies and molecular analysis, these eight species could be new to science in the world.