The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao 266071, China.
Fish Shellfish Immunol. 2009 Dec;27(6):684-94. doi: 10.1016/j.fsi.2009.08.013. Epub 2009 Sep 11.
Chinese mitten crab Eriocheir sinensis is one of the most important aquaculture crustacean species in China. A cDNA library was constructed from hemocytes of E. sinensis challenged with the mixture of Listonella anguillarum and Staphylococcus aureus, and randomly sequenced to collect genomic information and identify genes involved in immune defense response. Single-pass 5' sequencing of 10368 clones yielded 7535 high quality ESTs (Expressed Sequence Tags) and these ESTs were assembled into 2943 unigenes. BLAST analysis revealed that 1706 unigenes (58.0% of the total) or 4593 ESTs (61.0% of the total) were novel genes that had no significant matches to any protein sequences in the public databases. The rest 1237 unigenes (42.0% of the total) were closely matched to the known genes or sequences deposited in public databases, which could be classed into 20 or 23 classifications according to "molecular function" or "biological process" respectively based on the Gene Ontology (GO). And 221 unigenes (7.5% of all 2943 unigenes, 17.9% of matched unigenes) or 969 ESTs (12.9% of all 7535 ESTs, 32.9% of matched ESTs) were identified to be immune genes. The relative higher proportion of immune-related genes in the present cDNA library than that in the normal library of E. sinensis and other crustaceans libraries, and the differences and changes in percentage and quantity of some key immune-related genes especially the immune inducible genes between two E. sinensis cDNA libraries may derive from the bacteria challenge to the Chinese mitten crab. The results provided a well-characterized EST resource for the genomics community, gene discovery especially for the identification of host-defense genes and pathways in crabs as well as other crustaceans.
中华绒螯蟹（Eriocheir sinensis）是中国最重要的水产养殖甲壳类动物之一。本研究构建了中华绒螯蟹血细胞在鳗弧菌（Listonella anguillarum）和金黄色葡萄球菌混合物刺激下的 cDNA 文库，随机测序以收集基因组信息并鉴定参与免疫防御反应的基因。对 10368 个克隆的单端 5'测序产生了 7535 条高质量的 EST（表达序列标签），这些 EST 被组装成 2943 条基因。BLAST 分析显示，1706 条基因（总基因数的 58.0%）或 4593 条 EST（总 EST 数的 61.0%）是没有与公共数据库中任何蛋白质序列有显著匹配的新基因。其余 1237 条基因（总基因数的 42.0%）与公共数据库中已知基因或序列密切匹配，根据基因本体论（GO），可将其分为 20 或 23 个分类，分别根据“分子功能”或“生物学过程”。221 条基因（2943 条基因的 7.5%，匹配基因的 17.9%）或 969 条 EST（7535 条 EST 的 12.9%，匹配 EST 的 32.9%）被鉴定为免疫基因。与中华绒螯蟹正常组织文库和其他甲壳动物文库相比，本文库中免疫相关基因的相对比例较高，两个中华绒螯蟹 cDNA 文库中一些关键免疫相关基因，特别是免疫诱导基因的百分比和数量的差异和变化，可能源于中华绒螯蟹受到细菌的刺激。该结果为基因组学研究提供了一个特征明确的 EST 资源，有助于基因的发现，特别是在蟹类和其他甲壳动物中宿主防御基因和途径的鉴定。
