东方蜜蜂微孢子虫胁迫下意大利蜜蜂工蜂的piRNA差异表达谱及潜在功能

Differential expression profiles and potential function of piRNAs in Apis mellifera ligustica workers under Nosema ceranae stress

摘要:

为探究东方蜜蜂微孢子虫（Nosema ceranae）胁迫下意大利蜜蜂（Apis mellifera ligustica，简称意蜂）工蜂的piRNA差异表达表达谱及潜在功能，本研究利用前期获得的东方蜜蜂微孢子虫接种7 d和10 d的意蜂工蜂中肠（AmT1组和AmT2组）及未接种工蜂中肠（AmCK1组和AmCK2组）转录组数据筛选出宿主响应胁迫的差异表达piRNA(Differentially expressed piRNA, DEpiRNA)，并通过相关软件预测和分析DEpiRNA的靶mRNA，进而利用Stem-loop RT-PCR和qPCR对随机选取的DEpiRNA进行验证. 结果显示在AmCK1 vs AmT1和AmCK2 vs AmT2比较组分别筛选出50和207个DEpiRNA；上述两个比较组共有的DEpiRNA为10个，特有的DEpiRNA分别为40和197个；共有的DEpiRNA piR-ame-1128833可靶向3021条mRNA；Stem-loop RT-PCR验证结果显示4个DEpiRNA均真实表达；qPCR结果显示4个DEpiRNA的表达趋势与测序数据中的表达趋势一致. 研究结果揭示了东方蜜蜂微孢子虫胁迫引起意蜂工蜂中肠piRNA表达谱的改变；DEpiRNA可通过靶向相关mRNA潜在调控宿主对东方蜜蜂微孢子虫胁迫的响应.

Abstract:

To explore the differential expression profile and potential function of piRNAs in Apis mellifera ligustica workers under Nosema ceranae stress, the differentially expressed piRNA (DEpiRNAs) in the host response to stress were screened out by using previously abtained transcriptome data from A. m. ligustica workers’ midguts at 7 days post inoculation (dpi) and 10 dpi (AmT1 and AmT2 groups) as well as corresponding un-inoculated workers’ midguts (AmCK1 and AmCK2 groups), followed by prediction and investigation of target mRNAs of DEpiRNAs with relevant software, and randomly selected DEpiRNAs were further validated by Stem-loop RT-PCR and qPCR. The results showed that 50 and 207 DEpiRNAs were screened out from AmCK1 vs AmT1 and AmCK2 vs AmT2 comparison groups, respectively; there are 10 common DEpiRNAs shared by the aforementioned two comparison groups, and the numbers of unique DEpiRNAs were 40 and 197, respectively; the consensus DEpiRNA piR-ame-1128833 can target 3021 mRNAs; Stem-loop RT-PCR result confirmed the true expression of four DEpiRNAs; RT-qPCR result verified that the expression trend of four DEpiRNAs was in accordance with that in the sequencing data. These results reveal that the expression pattern of piRNAs in the midguts of A. m. ligustica workers was altered due to N. ceranae stress. DEpiRNA potentially regulated host response to N. ceranae stress through targeting associated mRNAs.