Abstract

As microRNAs (miRNAs) are important expression regulators of coding RNA, it is important to characterize their role in the interaction between hosts and pathogens. To obtain a comprehensive understanding of the miRNA alternation inBombyx mori(B. mori) infected withNosema bombycis(N. bombycis), RNA sequencing and stem-loop qPCR were conducted to screen and identify the significantly differentially expressed miRNAs (DEmiRNAs). A total of 17 such miRNAs were identified in response toN. bombycisinfection, among which miR6498-5p efficiently inhibited the proliferation ofN. bombycisin BmE-SWU1 (BmE) cells by downregulatingpyridoxal phosphate phosphatase 2(BmPLPP2). In addition, a fluorescence in situ hybridization (FISH) assay showed that miR6498-5p was located in the cytoplasm of BmE cells, while it was not found in the schizonts ofN. bombycis. Further investigation of the effect ofBmPLPP2on the proliferation of schizonts found that the positive factorBmPLPP2could facilitateN. bombyciscompleting its life cycle in cells by overexpression and RNAi ofBmPLPP2. Our findings offer multiple new insights into the role of miRNAs in the interaction between hosts and microsporidia.Keywords:B. mori;N. bombycis;microRNA;miR6498-5p;BmPLPP2;anti-microsporidian