Abstract: Apis cerana cerana is not only a specific honeybee species resource in China, but also a frequently-used honeybee species in apiculture. In the present study, the 5-(Ac5) and 6-day-old (Ac6) larval guts of A. c. cerana were sequenced using RNA-seq. After filtration, 29290630 and 26636038 clean reads with a Q20 of 98.45% and 98.38% were obtained in Ac5 and Ac6. GO enrichment analysis results showed that the highly expressed genes (HEGs) in Ac5 were enriched in 44 GO terms, among them metabolic process (753 unigenes), catalytic activity (679 unigenes) and binding (657 unigenes) were the largest groups; the HEGs in Ac6 were enriched in 44 GO terms, and the mostly enriched one was metabolic process (792 unigenes), followed by binding (760 unigenes) and catalytic activity (744 unigenes). KEGG enrichment analysis results suggested that the HEGs of Ac5 were enriched in 129 pathways, among them ribosome (103 unigenes) was the largest group, followed by protein processing in endoplasmic reticulum (68 unigenes) and carbon metabolism (67 unigenes); the HEGs of Ac6 were enriched in 129 pathways, the mostly enriched ones were ribosome (103 unigenes), oxidative phosphorylation (88 unigenes) as well as protein processing in endoplasmic reticulum (68 unigenes). Our findings can not only offer the gene expression profiles during the developmental process of the larval gut of A. c. cerana at transcriptome level, but also provide key information for further investigation of the larval gut's development.

Key words: RNA-seq, Apis cerana cerana, larval gut, highly expressed genes