Expression profiles of nce-miR-23928 and its target genes in the Nosema ceranae infection of Apis mellifera ligustica workers

Abstract:

[Background] Nosema ceranae exclusively infects midgut epithelial cells of adult bees, and the resulting microsporidiosis causes severe losses to the beekeeping industry. [Objective] This study aimed to determine the expression profiles of nce-miR-23928 and its target genes during the N. ceranae infection of Apis mellifera ligustica workers, and to provide basis for further investigation on the function and regulatory mechanism of nce-miR-23928 during the infection. [Methods] Target genes of nce-mir-23928 were predicted by RNAhybrid, miRanda and TargetScan. Blast was used to perform annotation of the aforementioned target genes in gene ontology (GO), kyoto encyclopedia of genes and genomes (KEGG), Nr and Swissprot. Real time quantitative PCR (RT-qPCR) was employed to detect relative expression of nce-miR-23928 and its target genes. [Results] As compared with the condition at 1 day post infection (1 dpi), the expression of nce-miR-23928 remained unchanged at 2 dpi, but was all down-regulated at 4 6, 8 dpi (P <0.05), presenting an overall reduced expression trend. Additionally, 15 target genes of nce-miR-23928 were predicted, among which 9, 4, 15 and 9 were annotated in GO (3 items), KEGG (7 pathways), Nr and Swiss-prot, respectively. As compared with the condition at 1 dpi, the expression of target gene ABCT was significantly down-regulated at 2, 4, 6, 8 dpi, while the expression of target gene STPK was significantly up-regulated at 4, 6, 8 dpi, displaying an overall elevation trend. [Conclusion] These results illuminated the dynamic expression rules of nce-miR-23928 and its target genes ABCT and SPTK in the N. ceranae infection of A. mellifera ligustica workers, and unraveled that nce-miR-23928 putatively modulated the infection process through positively regulating the expression of ABCT and negatively regulating the expression of STPK.