Rhodes L D, Grayson T H, Alexander S M, Strom M S
REUT Division, Northwest Fisheries Science Center, NMFS, NOAA, US Department of Commerce, Seattle, WA 98112, USA.
Gene. 2000 Feb 22;244(1-2):97-107. doi: 10.1016/s0378-1119(99)00573-9.
Renibacterium salmoninarum, a slowly growing, Gram-positive bacterium, is responsible for bacterial kidney disease in salmonid fishes world-wide. To date, no mobile genetic elements have been reported for this pathogen. Here, we describe the first insertion sequence (IS) identified from R. salmoninarum. This element, IS994, has a significant predicted amino acid sequence homology (64.8 and 71.9%) to the two open reading frames encoding the transposase of IS6110 of Mycobacterium tuberculosis. Protein parsimony and protein distance matrix analyses show that IS994 is a member of group IS51 of the IS3 family. From a conservative estimate, there are at least 17 chromosomal insertions of IS994 or closely related elements. Sequence analysis of seven of these loci reveals single nucleotide polymorphisms throughout the element (including the terminal inverted repeats), a 15bp insertion in three of the seven loci, and an absence of flanking direct repeats or conserved insertion site. Restriction fragment length polymorphism analysis of XbaI-digested chromosomal DNA shows variations among European and North American isolates, indicating that IS994 may be a useful molecular marker for epizootiological studies.
鲑肾杆菌是一种生长缓慢的革兰氏阳性菌，在全球范围内导致鲑科鱼类细菌性肾病。迄今为止，尚未报道该病原体存在移动遗传元件。在此，我们描述了从鲑肾杆菌中鉴定出的首个插入序列（IS）。这个元件，即IS994，与编码结核分枝杆菌IS6110转座酶的两个开放阅读框具有显著的预测氨基酸序列同源性（分别为64.8%和71.9%）。蛋白质简约分析和蛋白质距离矩阵分析表明，IS994是IS3家族IS51组的成员。据保守估计，IS994或与之密切相关的元件在染色体上至少有17个插入位点。对其中7个位点的序列分析揭示了整个元件（包括末端反向重复序列）存在单核苷酸多态性，7个位点中的3个位点有一个15bp的插入，并且不存在侧翼直接重复序列或保守插入位点。用XbaI消化染色体DNA后的限制性片段长度多态性分析表明，欧洲和北美分离株之间存在差异，这表明IS994可能是用于流行病学研究的有用分子标记。
