Berchtold M, Breunig A, König H
Abteilung Angewandte Mikrobiologie, Universität Ulm, Germany.
J Eukaryot Microbiol. 1995 Jul-Aug;42(4):388-91. doi: 10.1111/j.1550-7408.1995.tb01599.x.
A trichomonad flagellate strain R1 was isolated from the hindgut contents of the termite Reticulitermes santonensis Feytaud. The flagellate was cultivated at 28 degrees C in anaerobic medium containing yeast extract, minerals and vitamins. The isolate fed on living bacteria. It showed the typical morphological and ultrastructural features of the trichomonads, closely resembling Trichomitus trypanoides. In order to determine its phylogenetic position the small subunit ribosomal DNA (SSU rDNA) of the flagellate was amplified in vitro using the polymerase chain reaction (PCR), cloned in a plasmid vector and sequenced. Comparison of the obtained sequence with so far available SSU rRNA/rDNA sequences showed strongest similarity (89%) to the sequence of Tritrichomonas foetus. The phylogenetic analysis with parsimony and distance matrix methods placed Trichomitus trypanoides strain R1 near by the root of the phylogenetically so far analyzed eukaryotic organisms. This confirms that termites harbour hindgut symbionts, which originate from very early evolved eukaryotes.
从桑氏散白蚁（Reticulitermes santonensis Feytaud）的后肠内容物中分离出一株毛滴虫鞭毛虫R1。该鞭毛虫在含有酵母提取物、矿物质和维生素的厌氧培养基中于28℃培养。该分离株以活细菌为食。它表现出毛滴虫典型的形态和超微结构特征，与类锥虫三毛滴虫（Trichomitus trypanoides）极为相似。为了确定其系统发育位置，使用聚合酶链反应（PCR）在体外扩增该鞭毛虫的小亚基核糖体DNA（SSU rDNA），克隆到质粒载体中并进行测序。将所得序列与目前可用的SSU rRNA/rDNA序列进行比较，结果显示与胎儿三毛滴虫（Tritrichomonas foetus）的序列相似度最高（89%）。用简约法和距离矩阵法进行的系统发育分析表明，类锥虫三毛滴虫菌株R1位于迄今为止系统发育分析的真核生物的根部附近。这证实了白蚁体内存在起源于非常早期进化的真核生物的后肠共生体。
