Yoon J H, Lee S T, Kim S B, Goodfellow M, Park Y H
Bioinformatics & Systematics Laboratory, Korean Collection for Type Cultures, Korea Research Institute of Bioscience and Biotechnology, Korea Institute of Science and Technology, Taejeon, Republic of Korea.
Int J Syst Bacteriol. 1997 Jul;47(3):661-9. doi: 10.1099/00207713-47-3-661.
In order to clarify interspecific relationships and to investigate the intraspecific phylogenetic structure of the genus Saccharomonospora, 16S to 23S ribosomal DNA (16S-23S) and 23S to 5S ribosomal DNA (23S-5S) internally transcribed spacers (ITSs) were used for sequence analyses. The 16S-23S and 23S-5S ITSs from 22 Saccharomonospora strains were amplified by PCR and directly sequenced. The average levels of nucleotide similarity of the 16S-23S and 23S-5S ITSs for the four valid species were 87.6% +/- 3.9% and 83% +/- 2.2%, respectively. For the most part, intraspecific sequence differences were not found in the two ITSs; the only exception was Saccharomonospora glauca K194, which differed from other S. glauca strains by 1 bp in the 23S-5S ITS. The Saccharomonospora viridis strains had a smaller 16S-23S ITS region than the other strains, which may be useful for differentiating these organisms from other Saccharomonospora species. The characteristics of the two ITS regions make them more useful than 16S rRNA sequences as a tool for defining and identifying Saccharomonospora strains. However, Saccharomonospora azurea K161T had two types of 23S-5S ITSs; rrnB, separated by XhoI digestion, had two additional nucleotides inserted between positions 52 and 55. Most of the 16S-23S and 23S-5S ITS sequences of S. azurea K161T and strains of "Saccharomonospora caesia" were identical; the only exception was rrnB in S. azurea K161T. The lengths and levels of sequence divergence of the two ITSs of Saccharomonospora sp. strain K180 were different from the lengths and levels of sequence divergence of the ITSs of other species. These findings suggest that a taxonomic revision of the genus Saccharomonospora is necessary. Two trees based on 16S-23S and 23S-5S ITS sequences revealed distinct interspecific relationships in the genus Saccharomonospora.
为了阐明糖单孢菌属种间关系并研究其种内系统发育结构，利用16S至23S核糖体DNA（16S - 23S）和23S至5S核糖体DNA（23S - 5S）内转录间隔区（ITS）进行序列分析。通过PCR扩增22株糖单孢菌菌株的16S - 23S和23S - 5S ITS，并直接测序。4个有效种的16S - 23S和23S - 5S ITS核苷酸相似性平均水平分别为87.6%±3.9%和83%±2.2%。在这两个ITS中，大部分情况下未发现种内序列差异；唯一的例外是绿糖单孢菌K194，其23S - 5S ITS与其他绿糖单孢菌菌株相比有1个碱基对的差异。绿色糖单孢菌菌株的16S - 23S ITS区域比其他菌株小，这可能有助于将这些菌株与其他糖单孢菌属物种区分开来。这两个ITS区域的特征使其作为定义和鉴定糖单孢菌菌株的工具比16S rRNA序列更有用。然而，天蓝糖单孢菌K161T有两种类型的23S - 5S ITS；经XhoI酶切分离的rrnB在第52和55位之间插入了两个额外的核苷酸。天蓝糖单孢菌K161T和“浅蓝糖单孢菌”菌株的大部分16S - 23S和23S - 5S ITS序列相同；唯一的例外是天蓝糖单孢菌K161T中的rrnB。糖单孢菌属菌株K180的两个ITS的长度和序列分歧水平与其他物种ITS的长度和序列分歧水平不同。这些发现表明有必要对糖单孢菌属进行分类修订。基于16S - 23S和23S - 5S ITS序列构建的两棵树揭示了糖单孢菌属中不同的种间关系。
