Comparative transcriptome analysis on the synthesis pathway of honey bee (Apis mellifera) mandibular gland secretions

Abstract

Secretions from mandibular glands (MGs) have important caste-specific functions that are associated with the social evolution of honey bees. To gain insights into the molecular architecture underlying these caste differences, we compared the gene expression patterns of MGs from queens, queenright workers (WQRs) and queenless workers (WQLs) using high-throughput RNA-sequencing technology. In total, we identified 46 candidate genes associated with caste-specific biosynthesis of fatty acid pheromones in the MG, including members of cytochrome P450 (CYP450) family and genes involved in fatty acid β-oxidation and ω-oxidation. For further identification of the CYP450s genes involved in the biosynthesis of MG secretions, we analyzed by means of qPCR, the expression levels of six of the CYP450 genes most abundantly expressed in the transcriptome analysis across different castes, ages, tasks and tissues. Our analysis revealed that CYP6AS8 and CYP6AS11, the most abundantly expressed CYP450 genes in worker and queen MGs, respectively, are selectively expressed in the MGs of workers and queens compared to other tissues. These results suggest that these genes might be responsible for the critical bifurcated hydroxylation process in the biosynthesis pathway. Our study contributes to the description of the molecular basis for the biosynthesis of fatty acid-derived pheromones in the MGs.

De novo characterization of Phenacoccus solenopsis transcriptome and analysis of gene expression profiling during development and hormone biosynthesis

“…This disparity was observed due to the close evolutionary relationship between A. pisum and P. solenopsis , which referred a common selection of genes between closely related insects. This pattern is different from the transcriptome studies of hemipterans, B. tabaci 40 , 41 , A. mellifera 42 , Myzus persicae 43 and A. gossypii 44 . These observations are likely due to non-availability of sufficient transcriptome data for the hemipteran species published during the study period.…”

Shotgun proteomics deciphered age/division of labor-related functional specification of three honeybee (Apis mellifera L.) exocrine glands

“…These frequently detected CYPs that were upregulated in workers, especially CYP305D1, which was worker upregulated [ 41 ], MG-selective, frequently detected, and with greater than 2-fold higher abundance in the nMGs than fMGs ( Table 4 and S14 Table ), are promising candidates for the worker type ω hydroxylation enzyme. Recently, Wu et al used RNA sequencing and quantitative reverse-transcription polymerase chain reaction analyses to suggest that CYP6AS8 and CYP6AS11 are responsible for the different hydroxylation processes in worker and queen MGs, respectively [ 62 ], which coincides well with our proteomics data. Further functional studies will be fruitful for elucidating the molecular basis of pheromone biosynthesis in the MG.…”

The transcriptomic changes associated with the development of social parasitism in the honeybee Apis mellifera capensis

“…A total of 11,136 genes were expressed over all samples, representing 79 % of the known honeybee genes (Elsik et al 2014). Therefore our sequencing results are in line with other recent RNAseq studies in honeybees (Niu et al 2014;Doublet et al 2016), or they even exceed their numbers 2-10 times (Aufauvre et al 2014;Wu et al 2016;Wu et al 2017).…”