中国农业科学 ›› 2020, Vol. 53 ›› Issue (17): 3606-3619.doi: 10.3864/j.issn.0578-1752.2020.17.017

• 畜牧·兽医·资源昆虫 • 上一篇    下一篇

蜜蜂球囊菌菌丝和孢子中微小RNA及其靶mRNA的比较分析

陈华枝(),祝智威(),蒋海宾,王杰,范元婵,范小雪,万洁琦,卢家轩,熊翠玲,郑燕珍,付中民,陈大福,郭睿()   

  1. 福建农林大学动物科学学院(蜂学学院),福州 350002
  • 收稿日期:2019-12-25 接受日期:2020-02-04 出版日期:2020-09-01 发布日期:2020-09-11
  • 通讯作者: 郭睿
  • 作者简介:陈华枝,E-mail:CHZ0720@outlook.com。|祝智威,E-mail:zzw15235470398@163.com
  • 基金资助:
    国家自然科学基金(31702190);国家现代农业产业技术体系建设专项(CARS-44-KXJ7);福建省自然科学基金(2018J05042);福建省教育厅中青年教师教育科研项目(JAT170158);福建农林大学杰出青年科研人才计划(xjq201814);福建农林大学科技创新专项(CXZX2017342, CXZX2017343);福建农林大学优秀硕士学位论文资助基金(陈华枝)

Comparative Analysis of MicroRNAs and Corresponding Target mRNAs in Ascosphaera apis Mycelium and Spore

CHEN HuaZhi(),ZHU ZhiWei(),JIANG HaiBin,WANG Jie,FAN YuanChan,FAN XiaoXue,WAN JieQi,LU JiaXuan,XIONG CuiLing,ZHENG YanZhen,FU ZhongMin,CHEN DaFu,GUO Rui()   

  1. College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002
  • Received:2019-12-25 Accepted:2020-02-04 Online:2020-09-01 Published:2020-09-11
  • Contact: Rui GUO

摘要:

【目的】蜜蜂球囊菌(Ascosphaera apis,球囊菌)专性侵染蜜蜂幼虫而导致白垩病。本研究旨在通过small RNA-seq(sRNA-seq)技术和生物信息学方法对球囊菌纯化菌丝(AaM)和纯化孢子(AaS)进行深度测序和比较分析,明确球囊菌菌丝miRNA和孢子miRNA的数量、结构和表达谱差异,并揭示菌丝和孢子共有miRNA、特有miRNA和差异表达miRNA(differentially expressed miRNA,DEmiRNA)及其靶mRNA与球囊菌菌丝和孢子生长、发育和病原致病性的潜在关系。【方法】实验室条件下获得纯培养的球囊菌,利用sRNA-seq技术对AaM和AaS分别进行测序,通过对原始读段(raw reads)进行过滤和质控获得有效标签序列(clean tags)。通过Venn分析筛选菌丝和孢子共有miRNA和特有miRNA。根据P≤0.05且|log2 fold change|≥1的标准筛选AaM vs AaS的DEmiRNA。对上述共有miRNA、特有miRNA和DEmiRNA的靶mRNA进行预测,并对靶mRNA进行GO及KEGG数据库注释。根据靶向结合关系构建DEmiRNA和靶mRNA的调控网络。利用RT-qPCR验证测序数据的可靠性。【结果】AaM和AaS中分别得到12 982 320和12 708 832条raw reads,经过滤和质控分别得到10 800 101和9 888 848条clean tags。AaM中miRNA的长度介于18—26 nt,AaS中miRNA的长度介于18—24 nt,分布miRNA数量最多的长度均为18 nt,AaM和AaS中首位碱基为U的miRNA数量最多。AaM和AaS中表达量最高的miRNA均为miR6478-x、miR10516-x和miR482-x。菌丝和孢子共有miRNA靶向结合5 946个mRNA,二者特有miRNA分别靶向结合6 141和6 346个mRNA。共有miRNA的靶mRNA主要参与代谢进程、细胞进程和催化活性等42个功能条目,以及翻译、碳水化合物代谢和能量代谢等120条通路。AaM vs AaS比较组包含93个DEmiRNA,可靶向结合6 090个mRNA,这些靶mRNA可注释到38个功能条目和120条通路。DEmiRNA与靶mRNA之间形成较为复杂的调控网络,miR-4968-y位于调控网络的中心且能够靶向结合多达118个mRNA。RT-qPCR结果显示5个DEmiRNA的表达趋势与测序数据一致,证实了本研究中测序数据的可靠性。【结论】球囊菌菌丝和孢子中的miRNA具有类似的结构特征,但表达谱表现出明显差异;菌丝和孢子可能通过特异性表达和差异表达部分miRNA对其生长、发育和生殖进行调控。

关键词: 蜜蜂球囊菌, 菌丝, 孢子, 微小RNA, 信使RNA, 靶向结合

Abstract: 【Objective】Ascosphaera apis exclusively infects honeybee larvae, resulting in chalkbrood disease. The objective of this study is to clarify the differences of number, structure and expression pattern of miRNAs between A. apis mycelium and spore based on deep sequencing and comparative analysis of purified mycelia (AaM) and spores (AaS) using small RNA-seq (sRNA-seq) and bioinformatics, and reveal the potential relationship between common miRNAs, specific miRNAs, differentially expressed miRNAs (DEmiRNAs) and their target mRNAs and the growth and development of mycelium and spore as well as pathogenesis of A. apis.【Method】The pure culture of A. apis was gained under lab condition. AaM and AaS were respectively sequenced using sRNA-seq technology. Clean tags were obtained after filtration and quality control of raw reads. Common miRNAs and specific miRNAs in AaM and AaS were screened out using Venn analysis. DEmiRNAs in the AaM vs AaS comparison group were filtered out following the criteria of P≤0.05 and |log2 fold change|≥1. Target mRNAs of common miRNAs, specific miRNAs and DEmiRNAs were predicted using related bioinformatic software. Target mRNAs mentioned above were respectively annotated to GO database and KEGG database. The regulatory network of DEmiRNAs and target mRNAs was constructed on basis of target binding relationship, followed by visualization with Cytoscape. RT-qPCR was conducted to verify the reliability of the sequencing data.【Result】In total, 12 982 320 and 12 708 832 raw reads were produced from AaM and AaS, and after strict quality control, 10 800 101 and 9 888 848 clean tags were gained, respectively. The length of specific miRNAs in AaM was distributed among 18-26 nt, while that in AaS was distributed among 18-24 nt. Additionally, most of the miRNAs were distributed in 18 nt. MiRNAs with the first base U in both AaM and AaS were the most abundant. MiRNAs with the highest expression levels in both AaM and AaS were miR6478-x, miR10516-x and miR482-x. These common miRNAs could target 5 946 mRNAs, while specific miRNAs in AaM and AaS could bind to 6 141 and 6 346 mRNAs, respectively. Targets of common miRNAs were annotated to 42 functional terms such as metabolism process, cellular process and catalytic activity, and 120 pathways including translation, carbohydrate metabolism and energy metabolism. In addition, a total of 93 DEmiRNAs were identified in AaM vs AaS comparison group, targeting 6 090 mRNAs annotated to 38 functional terms and 120 pathways. Moreover, complicated regulatory networks were formed between DEmiRNAs and target mRNAs, with miR-4968-y located in the center and linked to as many as 118 mRNAs. RT-qPCR result demonstrated the expression trend of five DEmiRNAs was consistent with that in the sequencing result, confirming the reliability of our sequencing data.【Conclusion】The structures of miRNAs in A. apis mycelium and spore were similar, whereas their expression patterns were obviously different; mycelium and spore may specifically and differentially express part of miRNAs to regulate their growth, development and reproduction.

Key words: Ascosphaera apis, mycelium, spore, miRNA, mRNA, target binding