Transcriptome analysis of development of different stages in Apis mellifera worker bees

【Objective】To screen and functional annotation analysis of differentially expressed genes(DEGs)among different stages of Apis mellifera worker bees based on transcriptomics,reveal signaling pathways related to development of worker bees,so as to provide basic data for in-depth analysis of the molecular regulation mechanism of growth and development of worker bees.【Method】The 3-day-old larvae,1-day-old pupae and 1-day-old eclosion worker bees were takenas the research objects. Transcriptome sequencing was performed by Illumina NovaSeq 6000 platform,and screening of DEGs ment analysis were performed,and then real-time quantative PCR(qRT-PCR)verification was conducted.【Result】After transcriptome sequencing,4823 DEGs(51.86% up-regulated,48.14% down-regulated)were screened between 3-dayold larvae and 1-day-old pupae of A. mellifera worker bees. 3295 DEGs were screened between 1-day-old pupae and 1-day-old eclosion worker bees(57.51% up-regulated,42.49% down-regulated),5267 DEGs(52.95% up-regulated, 47.05% down-regulated)were screened between 3-day-old larvae and 1-day-old eclosion worker bees. The annotated GO function entries in the GO database of the three instar differential genes were 43(between 3-day-old larvae and 1-day-old pupae),45(between 1-day-old pupae and 1-day-old eclosion worker bees),and 44(between 3-day-old larvae and 1-dayold eclosion worker bees)respectively,mainly involving cellular process,cell part,binding,etc. KEGG signaling pathway enrichment analysis results showed that 2905 DEGs were enriched in 332 KEGG signaling pathways between 3-dayold larvae and 1-day-old pupae,of which 17 KEGG signaling pathways were significantly enriched,involving ribosomes,oxidation phosphorylation and insect hormone biosynthesis. 1644 DEGs were enriched in 331 KEGG signaling pathways between 1-day-old pupae and 1-day-old eclosion worker bees,of which 45 KEGG signaling pathways were significantly enriched,involving oxidative phosphorylation,thermogenesis and insulin secretion. 2958 DEGs were enriched in 337 KEGG signaling pathways between 3-day-old larvae and 1-day-old eclosion worker bees,of which 14 KEGG signaling pathways were significantly enriched,involving ribosomes,proteasomes and insulin secretion. The qRT-PCR results of 6 randomly selected DEGs were consistent with the transcriptome sequencing results,indicating that the transcriptome sequencing results were reliable.【Conclusion】The regulation of DEGs related to insect hormone biosynthesis pathway is consistent with the change rule of juvenile hormone(JH)titer in different stages of A. mellifera worker bees. The oxidative phosphorylation signaling pathway is related to the nutrient intake and activity behavior of different stages,and the insulin secretion pathway involves in the regulation of nutritional regulation,fat body synthesis and apoptosis of different stages. The results showsthat three signaling pathways of insect hormone biosynthesis,insulin secretion and oxidative phosphorylation play important roles in the developmental regulation of larvae,pupae and adult ofA. mellifera worker bees.