Department of Biomedical Science, College of Life Sciences, Ritsumeikan University, Noji Higashi 1–1–1, Kusatsu,Shiga 525–8577, Japan.
Microbes Environ. 2010;25(4):313-6. doi: 10.1264/jsme2.me10129.
The nuclear ribosomal RNA gene operon is interrupted by internal transcribed spacer (ITS) 1 and ITS2. Although the secondary structure of ITS2 has been widely investigated, less is known about ITS1 and its structure. In this study, the secondary structure of ITS1 sequences for Paramecium and other ciliates was predicted. Each Paramecium ITS1 forms an open loop with three helices, A through C. Helix B was highly conserved among Paramecium, and similar helices were found in other ciliates. A phylogenetic analysis using the ITS1 sequences showed high-resolution, implying that ITS1 is a good tool for species-level analyses.
核核糖体 RNA 基因操纵子被内部转录间隔区 (ITS) 1 和 ITS2 打断。尽管 ITS2 的二级结构已被广泛研究，但对 ITS1 及其结构的了解较少。在这项研究中，预测了 Paramecium 和其他纤毛虫的 ITS1 序列的二级结构。每个 Paramecium ITS1 形成一个带有三个螺旋 A 到 C 的开放环。螺旋 B 在 Paramecium 中高度保守，在其他纤毛虫中也发现了类似的螺旋。使用 ITS1 序列进行的系统发育分析显示出高分辨率，这意味着 ITS1 是进行种水平分析的良好工具。
