豪猪血蜱转录组测序分析

Transcriptome sequencing and analysis of Haemaphysalis hystricis ticks

目的测序分析豪猪血蜱转录组,比较雌、雄成蜱差异表达基因及其通路,为豪猪血蜱的防制提供参考。方法采用Illumina高通量技术对豪猪血蜱雌、雄成蜱进行转录组测序,将测序得到的数据进行拼接组装,利用生物信息学方法对所得序列进行功能注释、简单重复序列标记及雌雄蜱差异表达基因分析。结果共获得181246184个clean reads数据,组装后得到90957个unigenes序列,平均长度951。通过BLAST软件将所有unigenes序列与Nr,Nt,Pfam,KOG,Swiss-prot,KEGG,GO数据库进行比对。其中与Nr数据库比对发现豪猪血蜱基因序列与肩突硬蜱(Ixodes scapularis)具有较高的同源性,为51.2%;在GO数据库中,有150460个基因被注释,在56个功能群的二级分类中注释基因较多的是细胞过程(15274个);获得KOG注释的基因序列有19745个,将注释成功的基因按KOG的group进行分类,聚集较高的为一般功能预测基因2071个(16.85%);注释为KEGG代谢通路相关的序列共有12054个,在参与代谢通路5个分支中,细胞过程注释到的序列较高,为1765个(14.64%)。在各分支的亚支中,环境信息处理分支中的信号转导丰度较高(1270,10.54%)。通过SSR位点查找共鉴定出21883个SSR;SNP分析显示发生转换的SNP数为961890个,发生颠换的SNP数为509232个。结论通过对比豪猪血蜱雌、雄蜱差异表达基因及其通路,发现了胚胎发育和性别维持相关基因通路在雌蜱中的高表达,为豪猪血蜱控制策略的制定提供了理论基础。

Objective To use next-generation sequencing to determine the transcriptome of whole Haemaphysalis hystricis and to compare differentially expressed genes and their pathways in male and female adult ticks in order to provide clues for the control of H.hystricis.Methods The transcriptome of female and male adult ticks was sequenced using Illumina high-throughput technology.The raw data were compiled and subjected to bioinformatic methods to annotate sequences,mark simple repetitive sequences,and analyze the differentially expressed genes in male and female ticks.Results A total of 181,246,184 clean reads and 90,957 unigenes with an average length of 951 were obtained.All unigenes were compared with the NR,NT,Pfam,KOG,Swiss prot,KEGG,and GO databases using BLAST.According to the NR database,the gene sequence of H.hystricis shared 51.2%similarity to that of Ixodes scapularis.According to the GO database,150,460 genes were annotated.Among the 56 functional groups,the most annotated genes were Cellular Processes(15,274).In KOG,19,745 genes were annotated,and 2,071 genes(16.85%)were classified by groups;12,054 sequences were annotated as KEGG metabolic pathways.Among the five branches of metabolic pathways,1,765(14.64%)were annotated as cellular processes.Among the sub branches of each branch,the most abundant was signal transduction in the environmental information processing branch(1,270,10.54%).A total of 21,883 SSRs were identified via a search of SSR loci.SNP analysis indicated that 961,890 SNPs were transitions and 509,232 SNPs were transversions.Conclusion Comparison of the differentially expressed genes and their pathways in male and female H.hystricis revealed that gene pathways related to embryonic development and retention of sex were highly expressed in female ticks.This finding provides a theoretical basis for a strategy to control ticks.