Laboratory of Parasitology, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
PLoS One. 2011 Apr 6;6(4):e18267. doi: 10.1371/journal.pone.0018267.
Schistosoma japonicum is one of the remarkable Platyhelminths that are endemic in China and Southeast Asian countries. The parasite is dioecious and can reside inside the host for many years. Rapid reproduction by producing large number of eggs and count-react host anti-parasite responses are the strategies that benefit long term survival of the parasite. Praziquantel is currently the only drug that is effective against the worms. Development of novel antiparasite reagents and immune-prevention measures rely on the deciphering of parasite biology. The decoding of the genomic sequence of the parasite has made it possible to dissect the functions of genes that govern the development of the parasite. In this study, the polyadenylated transcripts from male and female S. japonicum were isolated for deep sequencing and the sequences were systematically analysed.
First, the number of genes actively expressed in the two sexes of S. japonicum was similar, but around 50% of genes were biased to either male or female in expression. Secondly, it was, at the first time, found that more than 50% of the coding region of the genome was transcribed from both strands. Among them, 65% of the genes had sense and their cognate antisense transcripts co-expressed, whereas 35% had inverse relationship between sense and antisense transcript abundance. Further, based on gene ontological analysis, more than 2,000 genes were functionally categorized and biological pathways that are differentially functional in male or female parasites were elucidated.
Male and female schistosomal parasites differ in gene expression patterns, many metabolic and biological pathways have been identified in this study and genes differentially expressed in gender specific manner were presented. Importantly, more than 50% of the coding regions of the S. japonicum genome transcribed from both strands, antisense RNA-mediated gene regulation might play a critical role in the parasite biology.
日本血吸虫是一种在我国和东南亚国家流行的显著扁形动物。该寄生虫是雌雄异体的，可以在宿主体内存活多年。通过大量产卵和宿主对抗寄生虫反应的计数来快速繁殖，是有利于寄生虫长期生存的策略。目前，吡喹酮是唯一有效的抗蠕虫药物。新型抗寄生虫试剂和免疫预防措施的开发依赖于对寄生虫生物学的破译。寄生虫基因组序列的解码使得解析控制寄生虫发育的基因功能成为可能。在这项研究中，从雌雄日本血吸虫中分离了多聚腺苷酸化转录本进行深度测序，并对序列进行了系统分析。
首先，雌雄日本血吸虫中活跃表达的基因数量相似，但约 50%的基因在表达上偏向于雄性或雌性。其次，首次发现基因组编码区的 50%以上是从两条链转录的。其中，65%的基因有意义，其对应的反义转录物共同表达，而 35%的基因在意义和反义转录物丰度之间存在反向关系。此外，基于基因本体论分析，超过 2000 个基因被功能分类，并阐明了在雄性或雌性寄生虫中具有不同功能的生物学途径。
雌雄日本血吸虫的基因表达模式存在差异，本研究中鉴定了许多代谢和生物学途径，并提出了在性别特异性方式下表达差异的基因。重要的是，日本血吸虫基因组的编码区有 50%以上是从两条链转录的，反义 RNA 介导的基因调控可能在寄生虫生物学中发挥关键作用。
