RNA反式剪接现象广泛存在于真核生物中，包括单细胞原虫以及低等脊索动物。本课题中我们运用Race方法从日本血吸虫中克隆出了一个90 nt的SL RNA基因，36 nt的RNA前导序列正是来源于此90 nt的无Poly A结构的SL RNA,并通过Northern进一步证实了该基因的存在。同时采用荧光定量和southern对其拷贝数、基因组上的分布方式以及虫体不同阶段的表达量进行了鉴定，发现SL RNA具有55个拷贝并在基因组上呈散在分布；在虫卵和尾蚴时期SL RNA基因的转录丰度最高，雌虫阶段最低，雄虫、3天童虫以及14天童虫阶段无明显差别。本课题的结果表明SL RNA介导的反式剪接可能是日本血吸虫基因转录后调控机制之一。

RNA trans-splicing occurs in a wide range of eukaryotes, from protozoa to chordates. Here we present the discovery of a spliced-leader (SL) RNA in the zoonotic trematode Schistosoma japonicum using Race. The 36-nucleotide SL in S. japonicum was derived from a 90-nucleotide nonpolyadenylylated RNA transcript encoded by 55 copies of SL genes dispersed in the genome confirmed by blot and real time PCR. Differential transcription patterns of the SL gene in the parasite developmental stages were observed using real time PCR. Predominant expression of SL RNA was found in the two developmental stages, egg and cercariae. Expression of SL RNA transcripts in female was the least. No significant expression difference between male and schistosomulum(3d and 14d)was observed. In summary, trans-splicing of spliced leader may act as a mechanism of post-transcriptional gene regulation in S. japonicum.