Protozoology Laboratory, Scientific Institute of Public Health - Louis Pasteur, J. Wytsmanstraat 14, B-1050 Brussels, Belgium.
Protist. 1998 Sep;149(3):221-8. doi: 10.1016/S1434-4610(98)70030-6. Epub 2009 Jul 13.
The ribosomal internal transcribed spacer (ITS), including the 5.8S rDNA, from the majority of the 11 described species of the amoeboflagellate Naegleria and from Willaertia magna have a size between 300 and 450 bp. In N. jadini and N. minor these products are approximately 750 bp long. The products from strains of the pathogenic N. fowleri vary between 323 and 423 bp. These length variations in N. fowleri are due to insertions of short repeats in the ITS1, causing the elongation of one stem-loop in the putative secondary structure. In all other species the sizes were identical from strains of the same species. In N. jadini and N. minor there are long inserts in the ITS2. Naegleria italica, N. clarki and N. galeacystis have shorter inserts in the ITS2. These inserts cause the elongation of one stem-loop in the putative secondary structure proposed for the ITS2. Because of the small differences in sequence between N. fowleri and N. lovaniensis the ITS does not provide target sequences for specifically identifying the pathogenic N. fowleri. However, differences in ITS1 do allow to distinguish different N. fowleri isolates. The ITS and 5.8S rDNA sequences will be of additional help in describing new Naegleria spp., which becomes more based on molecular data because morphological differences are scarce in these organisms.
核糖体内部转录间隔区（ITS），包括 5.8S rDNA，来自已描述的 11 种变形鞭毛虫中的大多数，包括棘阿米巴属 Naegleria 和巨滴虫属Willaertia magna，其大小在 300 到 450 bp 之间。在 N. jadini 和 N. minor 中，这些产物大约有 750 bp 长。致病性 N. fowleri 的菌株产生的产物在 323 到 423 bp 之间变化。N. fowleri 中的这些长度变化是由于 ITS1 中的短重复插入，导致假定二级结构中的一个茎环延长。在所有其他物种中，来自同一物种的菌株的大小是相同的。在 N. jadini 和 N. minor 中，ITS2 中有长插入。棘阿米巴属 Naegleria italica、N. clarki 和 N. galeacystis 在 ITS2 中有较短的插入。这些插入导致假定二级结构中一个茎环的延长。由于 N. fowleri 和 N. lovaniensis 之间序列的微小差异，ITS 不能提供特定识别致病性 N. fowleri 的靶序列。然而，ITS1 的差异确实允许区分不同的 N. fowleri 分离株。ITS 和 5.8S rDNA 序列将有助于描述新的棘阿米巴属，这将更多地基于分子数据，因为这些生物体的形态差异很少。
