本期Nature封面上的顯微照片（由David Scharf提供）所示為一對(duì)交配的曼氏血吸蟲(chóng)，大約放大了265倍,，較纖細(xì)的雌性出現(xiàn)在雄性的下半部分。
以中國(guó)國(guó)家人類(lèi)基因組南方中心為首的聯(lián)合課題組在本期Nature上報(bào)告了日本血吸蟲(chóng)（Schistosoma japonicum）的完整基因組序列,，本期Nature同樣還發(fā)布了一篇曼氏血吸蟲(chóng)（Schistosoma mansoni）測(cè)序的文章,。兩篇文章并列作為本期Nature封面。
曼氏血吸蟲(chóng)和日本血吸蟲(chóng)是引起血吸蟲(chóng)?。ㄒ卜Q(chēng)“裂體血吸蟲(chóng)病”）的三種主要病原體中的兩種,。世界上共有埃及血吸蟲(chóng)、曼氏血吸蟲(chóng),、日本血吸蟲(chóng),、間插血吸蟲(chóng),、湄公血吸蟲(chóng)等5種寄生于人體的血吸蟲(chóng),。
血吸蟲(chóng)病是一種“被忽視的”熱帶疾病,，影響76個(gè)國(guó)家的超過(guò)2億人,。血吸蟲(chóng)病有急性,、慢性之分,。急性血吸蟲(chóng)病是在大量感染尾蚴的情況下發(fā)生的,，病人發(fā)病迅猛,，可在短期內(nèi)發(fā)展成為晚期或直接進(jìn)入衰竭狀態(tài),，導(dǎo)致死亡,。慢性血吸蟲(chóng)病一般發(fā)展較慢，早期對(duì)體力有不同程度的影響,，進(jìn)入晚期后則出現(xiàn)腹水,、巨脾、侏儒等癥,，患者勞動(dòng)力喪失,，甚至造成死亡。
研究顯示,，血吸蟲(chóng)基因組由近4億個(gè)堿基組成,，含有40.1%的重復(fù)序列，包括新發(fā)現(xiàn)的具有轉(zhuǎn)錄活性的反轉(zhuǎn)座子25個(gè),。研究工作識(shí)別編碼基因13469個(gè),，其中有首次發(fā)現(xiàn)的與血吸蟲(chóng)感染宿主密切相關(guān)的彈力蛋白酶(Elastase)。有趣的是,，血吸蟲(chóng)與具有同等大小基因組的非寄生生物比較,，雖然基因數(shù)量相似，但功能基因的組成卻有較大差別。一方面它丟失了很多與營(yíng)養(yǎng)代謝相關(guān)的基因,，如脂肪酸,、氨基酸、膽固醇和性激素合成基因等,，這些營(yíng)養(yǎng)物質(zhì)必須從哺乳動(dòng)物宿主獲得,；另一方面，擴(kuò)充了許多有利于蛋白消化的酶類(lèi)基因家族的成員,。這一變化充分體現(xiàn)了血吸蟲(chóng)適應(yīng)寄生生活,，與宿主協(xié)同進(jìn)化的重要特性。
研究還揭示,，血吸蟲(chóng)像其他多細(xì)胞生物一樣,，具有與發(fā)育密切相關(guān)的多條重要分子信號(hào)途徑,；血吸蟲(chóng)有原始的中樞神經(jīng)系統(tǒng)和較為完善的外周感覺(jué)神經(jīng)系統(tǒng),，能接受周?chē)h(huán)境發(fā)出的聲、光,、機(jī)械振動(dòng)等信號(hào),，有助于攻擊宿主并到達(dá)營(yíng)養(yǎng)豐富的器官，如肝臟門(mén)靜脈,、腸靜脈等處寄生,。血吸蟲(chóng)雖然不像高級(jí)哺乳動(dòng)物那樣有下丘腦、垂體,、甲狀腺,、性腺等神經(jīng)內(nèi)分泌器官，但是它有類(lèi)似功能的細(xì)胞,，編碼一些與生長(zhǎng),、發(fā)育和成熟相關(guān)的內(nèi)分泌激素受體，除了接受本身合成的內(nèi)分泌激素外,，還可以接受宿主的激素作用,，甚至形成依賴(lài)宿主內(nèi)分泌激素的寄生狀態(tài)。
血吸蟲(chóng)能編碼并分泌彈力蛋白酶消化宿主如人,、牛等皮膚組織而進(jìn)入體內(nèi)形成危害,。血吸蟲(chóng)在致病過(guò)程中，除了編碼蛋白酶消化宿主皮膚和血液外,，還分泌一些炎癥相關(guān)分子如前列腺素,、聚糖、脂質(zhì),、自身抗原樣蛋白等,，這些因子可誘導(dǎo)宿主免疫反應(yīng)，形成肉芽腫等免疫損傷,，導(dǎo)致嚴(yán)重的血吸蟲(chóng)病,。
相關(guān)研究成果從基因組進(jìn)化的高度,，為認(rèn)識(shí)血吸蟲(chóng)生物學(xué)特征、理解宿主與寄生蟲(chóng)的相互關(guān)系,、拓寬分子寄生蟲(chóng)學(xué)和分子進(jìn)化等研究領(lǐng)域提供了系統(tǒng)的創(chuàng)新知識(shí)和分析工具,。血吸蟲(chóng)除了有大量與其他物種同源的基因外，還有許多血吸蟲(chóng)特有基因,。這也為生物醫(yī)學(xué)界認(rèn)識(shí)血吸蟲(chóng)生物學(xué)特征,、開(kāi)發(fā)抗血吸蟲(chóng)藥物以及研制血吸蟲(chóng)疫苗奠定了理論基礎(chǔ)。
這兩種血吸蟲(chóng)的基因組是首次被測(cè)序的兩種扁形蟲(chóng)基因組,，所以它們?yōu)榱私鈩?dòng)物演化中的早期事件,、尤其是身體模式的確定及組織發(fā)育成器官的過(guò)程提供了新視角。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 460, 345-351 (16 July 2009) | doi:10.1038/nature08140
The Schistosoma japonicum genome reveals features of host–parasite interplay
The Schistosoma japonicum Genome Sequencing and Functional Analysis Consortium
1 Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, 250 Bi Bo Road, Shanghai 201203, China.
2 School of Life Science/Institutes of Biomedical Sciences, Fudan University, 220 Han Dan Road, Shanghai 200433, China.
3 Shanghai Center for Bioinformation Technology, 100 Qinzhou Road, Shanghai 200235, China.
4 Cheriton School of Computer Science, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
5 Comparative Genomics Centre/School of Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia.
6 State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology, RuiJin Hospital, School of Medicine, Shanghai Jiao Tong University, 197 Rui Jin Road II, Shanghai 200025, China.
7 National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Er Road, Shanghai 200025, China.
8 Shanghai Center for Biochip Engineering, 151 Li Bing Road, Shanghai 201203, China.
9 Department of Microbiology, Immunology & Tropical Medicine, George Washington University Medical Center, Ross Hall, Room 448, 2300 I Street, NW, Washington DC 20037, USA.
10 Molecular Parasitology Laboratory, Queensland Institute of Medical Research, 300 Herston Road, Brisbane, Queensland 4006, Australia.
11 Beijing Institute of Genomics, Chinese Academy of Sciences/Beijing Genomics Institute, B-6 Beijing Airport Industrial Zone, Beijing 101300, China.
12 Pathogen Sequencing Unit, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton CB10 1SA, UK.
13 Genome Institute of Singapore, 60 Biopolis Street, Genome #02-01, 138672, Singapore.
14 Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
This article is distributed under the terms of the Creative Commons Attribution-Non-Commercial-Share Alike licence (http://creativecommons.org/licenses/by-nc-sa/3.0/), which permits distribution, and reproduction in any medium, provided the original author and source are credited. This license does not permit commercial exploitation, and derivative works must be licensed under the same or similar licence.
Schistosoma japonicum is a parasitic flatworm that causes human schistosomiasis, which is a significant cause of morbidity in China and the Philippines. Here we present a draft genomic sequence for the worm. The genome provides a global insight into the molecular architecture and host interaction of this complex metazoan pathogen, revealing that it can exploit host nutrients, neuroendocrine hormones and signalling pathways for growth, development and maturation. Having a complex nervous system and a well-developed sensory system, S. japonicum can accept stimulation of the corresponding ligands as a physiological response to different environments, such as fresh water or the tissues of its intermediate and mammalian hosts. Numerous proteases, including cercarial elastase, are implicated in mammalian skin penetration and haemoglobin degradation. The genomic information will serve as a valuable platform to facilitate development of new interventions for schistosomiasis control.
