Stothard J R, Hughes S, Rollinson D
Dept of Zoology, The Natural History Museum, Cromwell Road, London UK.
Acta Trop. 1996 Mar;61(1):19-29. doi: 10.1016/0001-706x(95)00137-4.
Species within the genus Bulinus are responsible for transmission of schistosomes within the Schistosoma haematobium group. In order to provide a molecular insight into the species relationships within the genus, genetic variation between species representing the four species groups was assayed by Polymerase Chain Reaction (PCR) amplification of the ribosomal Internal Transcribed Spacer (ITS) region followed by Restriction Fragment Length Polymorphism (RFLP) analysis of this product with six restriction enzymes. This PCR-RFLP methodology detected considerable variation within the ITS region indicating that restriction profiles will be useful as genetic markers for identification purposes. The complete ITS1 spacer was sequenced for B. globosus, B. cernicus and B. truncatus. There were numerous nucleotide differences between taxa mainly insertions and deletions. Nucleotide divergence was calculated between species from the restriction profiles: the B. truncatus/tropicus complex and B. reticulatus group were most similar which were in turn more closely related to the B. africanus group than to the B. forskalii group. The nucleotide divergence between the species groups is substantial and questions the placement of these groups within the same genus.
水泡螺属的物种是埃及血吸虫组内血吸虫传播的媒介。为了从分子层面深入了解该属内的物种关系，通过聚合酶链反应（PCR）扩增核糖体内部转录间隔区（ITS），随后用六种限制性内切酶对该产物进行限制性片段长度多态性（RFLP）分析，测定了代表四个物种组的物种之间的遗传变异。这种PCR-RFLP方法检测到ITS区域内存在相当大的变异，表明限制性酶切图谱将作为用于鉴定目的的遗传标记。对球形水泡螺、塞氏水泡螺和截形水泡螺的完整ITS1间隔区进行了测序。不同分类单元之间存在许多核苷酸差异，主要是插入和缺失。根据限制性酶切图谱计算了物种之间的核苷酸差异：截形水泡螺/热带水泡螺复合体和网状水泡螺组最为相似，它们与非洲水泡螺组的关系又比与福氏水泡螺组更为密切。物种组之间的核苷酸差异很大，这对这些组在同一属内的分类提出了质疑。
