中国明对虾和中华绒螯蟹EST的Blast2GO注释及其在免疫基因分布研究中的应用

以dbEST数据库中公布的中国明对虾和中华绒螯蟹的EST序列作为数据源,利用CAP3对其进行聚类拼接,采用Blast2GO软件进行功能注释,并通过查找免疫相关的GO注释和检索免疫关键词的方法寻找免疫相关基因,经与不同物种免疫基因的比较,推测可能的免疫基因序列,并进一步分析免疫基因在不同组织和细胞中的分布.结果表明,通过注释和关键词进行筛选这2种方法具有较好的互补性;预测了位于中国明对虾头胸部的60个可能的免疫基因以及位于中华绒螯蟹血细胞hemocyte、haemocyte、肝胰腺、性腺和精巢中的250个免疫基因,这些基因包括模式识别受体、抗氧化蛋白、抗菌肽、凝集素等,其中部分参与酚氧化酶原激活系统、Toll信号通路等重要免疫过程.中华绒螯蟹血细胞中具有种类丰富的免疫基因,与已有的甲壳动物免疫系统相符合.肝胰腺中发现了模式识别蛋白、蛋白酶以及数量众多的凝集素种类,提示肝胰腺在免疫过程中也发挥了一定作用.

Blast2GO annotation and application for distribution of immune genes of Fenneropenaeus chinensis and Eriocheir sinensis EST

The published ESTs of Fenneropenaeus chinensis and Eriocheir sinensis in dbEST were downloaded separately as data sources. Sequences in each EST were assembled into Unigenes by CAP3 and annotated by Blast2Go software, then immune-related Unigenes were screened according to the relevant GO terms and immune-related keywords. In comparison with different organisms, the putative immune-related genes were predicted and the distribution of these genes in cells and tissues were analyzed. The results showed 60 putative immune-related Unigenes in cephalothorax of F. chinensis and 250 putative immune-related Unigenes in hemocyte, haemocyte, hepatopancreas, sex gland testis of E. sinensis separately. These immune-related Unigenes included pattern recognition proteins, antioxidant protein, antibacterial peptides, lectin, etc. Some of them were involved in immune process, such as prophenol-oxidase activated system （proPO-AS）, toll signal pathway. There were a variety of immune-related Unigenes in hemocytes of E. sinensis, which was in accordance with the existing immune system of crustacean. In addition, a lot of immune-related Unigenes, such as pattern recognition pro- teins, proteases and a variety of lectins, were found in the hepatopancreas of E. sinensis, which means that hepatopan- creas may play an important role in innate immune process of crustacean.