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Antennal Transcriptome Profiling Reveals Gustatory Receptors Associated with Pollen Foraging Preferences in Apis mellifera
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College of Animal Science, Shanxi Agricultural University, Jinzhong 030801, China
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Shanxi Key Laboratory of Animal Nutrition and Feed Development, College of Animal Science, Shanxi Agricultural University, Jinzhong 030801, China
3
College of Horticulture, Shanxi Agricultural University, Jinzhong 030801, China
*
Authors to whom correspondence should be addressed.
Animals 2026, 16(13), 2067; https://doi.org/10.3390/ani16132067 (registering DOI)
Submission received: 28 May 2026
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Revised: 19 June 2026
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Accepted: 2 July 2026
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Published: 4 July 2026
(This article belongs to the Section Animal Genetics and Genomics)
Simple Summary
Honeybees rely on their antennae to detect chemical signals from flowers, helping them choose suitable pollen and nectar sources during foraging. However, the molecular basis underlying how honeybees recognize different floral resources remains poorly understood. In this study, we compared gene expression in the antennae of western honeybees (Apis mellifera) collecting pear pollen, rapeseed pollen, and no pollen. Transcriptome sequencing identified hundreds of genes that were differently expressed among the groups, many of which were associated with sensory perception, signal transmission, metabolism, and environmental response. We further identified seven gustatory receptor genes related to taste perception in honeybee antennae. Three genes were associated with sugar detection, while four genes were likely involved in bitter substance perception. These genes may help honeybees distinguish floral resources and avoid harmful compounds during foraging. The expression patterns of these genes were further confirmed using quantitative real-time PCR analysis. This study improves our understanding of how honeybees recognize and select different pollen sources at the molecular level. The findings provide valuable information for honeybee behavioral research, pollination biology, and the sustainable management of agricultural pollination resources.
Abstract
Gustatory perception in honeybees is a key determinant of foraging decisions and pollen source selection. However, the molecular mechanisms underlying this sensory discrimination remain poorly understood. To investigate these mechanisms during the collection of pollen from different floral sources, this study utilized antennae from worker bees foraging on pear and rapeseed pollen, and non-pollen-foraging workers as controls. Illumina high-throughput transcriptome sequencing was employed to identify differentially expressed genes (DEGs), perform functional annotation, and characterize gustatory receptor (GR) genes. Compared with the control group, 583 DEGs and 516 DEGs were identified in pear-pollen and rapeseed-pollen foragers, respectively, whereas only 73 DEGs were detected between the two pollen-foraging groups. Several DEGs were associated with chemosensory perception, signal transduction, energy metabolism, and immune responses. Notably, genes involved in membrane-associated signaling and stimulus response exhibited differential expression patterns among foraging groups, suggesting adaptive molecular responses to distinct floral resources. Gene Ontology (GO) analysis indicated that DEGs were primarily associated with cellular processes, membrane components, and binding functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment highlighted significant involvement in phagosome, phosphatidylinositol signaling system, oxidative phosphorylation, and extracellular matrix–receptor interaction. Notably, seven GR-related genes were identified in the antennal transcriptome, including five known GR genes and two novel candidates, all with complete open reading frames. Four of these genes featured the canonical seven-transmembrane domain structure of insect GRs. Phylogenetic analysis, in addition to the known sugar receptors AmelGR43a, AmelGR64f, and AmelGR64f-X1, based on GRs from Apis mellifera and Drosophila melanogaster suggested that AmelGR28b, AmelGR10, AmelGR12, and AmelGR13 may belong to the bitter taste receptor family. Quantitative real-time PCR (qRT-PCR) validation demonstrated that the expression patterns of the selected seven DEGs were consistent with the RNA-seq results. This study reveals differential expression patterns and potential functional divergence of gustatory receptor genes in Apis mellifera during pollen collection from different floral sources. It provides important molecular evidence for understanding how honeybees accurately recognize and preferentially forage specific pollen sources via gustatory perception, and offers valuable theoretical and practical insights for honeybee behavioral ecology and crop pollination management.
