Zhang Yinfeng, Arias Covadonga R
Department of Fisheries and Allied Aquacultures, Auburn University, 203 Swingle Hall, Auburn, AL-36849, USA.
Syst Appl Microbiol. 2007 Mar;30(2):93-101. doi: 10.1016/j.syapm.2006.04.004. Epub 2006 May 11.
Comparison of the 23S rRNA gene sequences of Edwardsiella tarda and Edw. ictaluri confirmed a close phylogenetic relationship between these two fish pathogen species and a distant relation with the 'core' members of the Enterobacteriaceae family. Analysis of the rrl gene for 23S rRNA in Edw. ictaluri revealed the presence of an intervening sequence (IVS) in helix-45. This new 98bp IVS shared 97% nucleotide identity with Salmonella typhimurium helix-45 IVS. Edw. ictaluri helix-45 IVS was present in all Edw. ictaluri strains analyzed and in at least six rrl operons within each cell. Fragmentation of 23S rRNA due to IVS excision by RNase III was observed by methylene blue staining of ribosomal RNA extracted from Edw. ictaluri isolates. This is the first report of an IVS in the 23S rRNA gene of the genus Edwardsiella.
迟缓爱德华氏菌和鲶鱼爱德华氏菌23S rRNA基因序列的比较证实了这两种鱼类病原体之间密切的系统发育关系，以及它们与肠杆菌科“核心”成员的远亲关系。对鲶鱼爱德华氏菌中23S rRNA的rrl基因分析显示，在螺旋-45中存在一个间隔序列（IVS）。这个新的98bp IVS与鼠伤寒沙门氏菌螺旋-45 IVS的核苷酸同一性为97%。鲶鱼爱德华氏菌螺旋-45 IVS存在于所有分析的鲶鱼爱德华氏菌菌株中，且每个细胞内至少有六个rrl操纵子中存在该序列。通过对从鲶鱼爱德华氏菌分离株中提取的核糖体RNA进行亚甲蓝染色，观察到由于RNase III切除IVS导致23S rRNA片段化。这是爱德华氏菌属23S rRNA基因中存在IVS的首次报道。
