Genome-wide characterization of long intergenic non-coding RNAs (lincRNAs) provides new insight into viral diseases in honey bees Apis cerana and Apis mellifera

Background: Long non-coding RNAs (lncRNAs) are a class of RNAs that do not encode proteins. Recently, lncRNAs have gained special attention for their roles in various biological process and diseases. Results: In an attempt to identify long intergenic non-coding RNAs (lincRNAs) and their possible involvement in honey bee development and diseases, we analyzed RNA-seq datasets generated from Asian honey bee (Apis cerana) and western honey bee (Apis mellifera). We identified 2470 lincRNAs with an average length of 1011 bp from A. cerana and 1514 lincRNAs with an average length of 790 bp in A. mellifera. Comparative analysis revealed that 5 % of the total lincRNAs derived from both species are unique in each species. Our comparative digital gene expression analysis revealed a high degree of tissue-specific expression among the seven major tissues of honey bee, different from mRNA expression patterns. A total of 863 (57 %) and 464 (18 %) lincRNAs showed tissue-dependent expression in A. mellifera and A. cerana, respectively, most preferentially in ovary and fat body tissues. Importantly, we identified 11 lincRNAs that are specifically regulated upon viral infection in honey bees, and 10 of them appear to play roles during infection with various viruses. Conclusions: This study provides the first comprehensive set of lincRNAs for honey bees and opens the door to discover lincRNAs associated with biological and hormone signaling pathways as well as various diseases of honey bee.