Identification of Ascosphaera apis microRNAs and investigation of their regulation networks

Abstract:

[Objective] In this study, pure culture of A. apis was sequenced using sRNA-seq technology, followed by prediction, identification and analysis of A. apis microRNAs. The microRNAs-mRNAs regulation network was further constructed. [Methods] Illumina Hiseq Xten platform was used to sequence mycelium and spores of A. apis, and corresponding softwares were used to predict and analyze A. apis microRNAs, some of which were identified via Stem-loop PCR. Cytoskype software was used to construct A. apis microRNAs-mRNAs regulation network. [Results] A total of 48268696 clean reads were obtained, and 118 miRNAs of A. apis were predicted, whose length was distributed between 18 nt and 25 nt. The preference of the first base of miRNAs with different length was obviously various. Stem-loop PCR result showed target fragments with expected sizes were amplified from 10 microRNAs, implying most of the predicted microRNAs' true existence. In total, 6529 target genes of A. apis microRNAs were predicted, and among them 5725 could be annotated in Nr, Swissprot, KOG, GO and KEGG databases. Further investigation demonstrated 24 target genes were annotated in MAPK signaling pathway. Cytoskype software analysis suggested complicated regulation networks exist between microRNAs and mRNAs in A. apis, and majority of miRNAs inside the networks bind to several mRNAs. [Conclusion] Our findings enrich the understanding of A. apis microRNAs, provide beneficial supplement for basic biology information of A. apis, and lay some foundation for illustrating the molecular mechanism regulating the pathogenesis of this widespread fungal pathogen.

Key words:honeybee;Ascosphaera apis;microRNA;target gene;regulation network