Hamburger J, Abbasi I, Ramzy R M, Jourdane J, Ruppel A
Kuvin Centre, Hebrew University, Hadassah Medical School, Jerusalem, Israel.
Am J Trop Med Hyg. 2001 Dec;65(6):907-11. doi: 10.4269/ajtmh.2001.65.907.
We have cloned from Schistosoma haematobium genome a repeated sequence, the DraI repeated sequence, which consists of tandemly arranged 121-bp-long units and which is highly abundant (approximately 15% of the S. haematobium genome). By these features, the DraI repeat is similar to the Sm1-7 sequence of Schistosoma mansoni previously described by us. However, their nucleotide sequences are profoundly different. Polymerase chain reaction (PCR) primers were designed on the basis of the DraI sequence information and were used in a PCR assay by which as little as 10 fg of schistosomal DNA as well as individual cercariae were detected. The DraI repeat cross-hybridized with DNA from Schistosoma bovis, Schistosoma magrebowiei, Schistosoma mattheei, Schistosoma curassoni, and Schistosoma intercalatum, but not with DNA from S. mansoni nor from Trichobilharzia ocellata and Echinostoma sp. A potential value of this PCR assay is suggested for monitoring free-living cercariae and infected snails only in bodies free of cross-hybridizing species.
我们从埃及血吸虫基因组中克隆出了一个重复序列，即DraI重复序列，它由串联排列的121个碱基对长的单元组成，且高度丰富（约占埃及血吸虫基因组的15%）。基于这些特征，DraI重复序列与我们之前描述的曼氏血吸虫的Sm1-7序列相似。然而，它们的核苷酸序列却有很大差异。根据DraI序列信息设计了聚合酶链反应（PCR）引物，并将其用于PCR检测，该检测能够检测低至10 fg的血吸虫DNA以及单个尾蚴。DraI重复序列与来自牛血吸虫、马格里布血吸虫、马修血吸虫、库拉索血吸虫和间插血吸虫的DNA发生交叉杂交，但与曼氏血吸虫以及卵形毛毕吸虫和棘口吸虫属的DNA不发生杂交。该PCR检测方法的潜在价值在于，仅在没有交叉杂交物种的宿主体内监测自由生活的尾蚴和受感染的蜗牛。
