mRNA and Small RNA-seq Reveal Insights into Immune Regulation in Apis cerana after Chinese Sacbrood Virus Infection

Chinese sacbrood virus (CSBV) is a serious threat to eastern honeybees (), especially larvae. However, the pathological mechanism of this deadly disease is remains unclear. Here, we employed an mRNA-seq and sRNA-seq approach in healthy and CSBV-infected 3 larval. Gene ontology (GO) and KEGG analysis of 203 differentially expressed genes showed that CSBV infection affected host development by up-regulating the expression of larval cuticle proteins, such as larval cuticle proteins A1A and A3A, resulting in elevated susceptibility to CSBV. In addition, viral infection not only affected the expression of serine protease related to the melanization pathway and but also altered fatty acid metabolism and biosynthesis, thus progressed to disturb host immune response. Interestingly, GO annotation and KEGG analysis on target genes of CSBV-specific siRNA (vsiRNAs) showed that serine/threonine kinase activity and serine-type endopeptidas as well as fatty acid biosynthesis were significantly enriched (P < 0.05). Among these vsiRNAs, vsiRNA-1441 with relatively high expression targeted extracellular serine/threonine protein kinase. This study provides new evidence that CSBV attacks a distinct immune response pathway and mediates the expression of cuticle protein to gain the more chance of proliferation.