Immune gene expression and locomotor activity in response to Vairimorpha ceranae infection across five honey bee subspecies

Authors: TOZKAR, CANSU - Yuzuncu Yil Centennial University; Evans, Jay

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2025
Publication Date: 6/5/2025
Citation: Tozkar, C., Evans, J.D. 2025. Immune gene expression and locomotor activity in response to Vairimorpha ceranae infection across five honey bee subspecies. Insects. 16. Article 6060593. https://doi.org/10.3390/insects16060593.
DOI: https://doi.org/10.3390/insects16060593

Interpretive Summary: Honey bees play a critical role in food production and environmental health, yet they are increasingly threatened by parasites that compromise bee health by interfering with immune defenses and altering behavior. To identify bee vulnerability, this study explored how five honey bee subspecies responded to parasite infection. Overall, our findings show that genetics matter, in that different bee types react differently to infection. This work shows that certain bee lineages resist or succumb to a key parasite, which can be used by bee breeders and beekeepers to select for better genetics and maintain healthier bee populations.

Technical Abstract: This study evaluated immune-gene expression and locomotor behavior across five Apis mellifera subspecies (Carniolan, Caucasian, Syrian, Mugla ecotype, and Yigilca ecotype) following controlled Vairimorpha ceranae infection. Six days post-infection, Caucasian, Carniolan, and Yigilca bees exhibited significant upregulation of antimicrobial peptide (AMP) transcripts—hymenoptaecin, abaecin, defensin, and apidaecin—indicating a robust humoral response. Conversely, Syrian and Mugla bees showed weaker AMP expression and higher V. ceranae mRNA levels, indicating lower immunity and higher susceptibility. Positive correlations among AMP transcripts, especially in Caucasian, Carniolan, and Yigilca bees, 2 suggested a coordinated response. Locomotor analysis revealed subspecies-specific behavioral responses. Syrian bees maintained the highest activity despite elevated V. ceranae mRNA and minimal AMP expression, suggesting unique resilience. Mugla bees, with high pathogen loads, exhibited decreased activity. Caucasian bees showed strong immune responses but reduced activity post-infection, reflecting potential physiological trade-offs. Overall, these findings underscore role of genetic variability in shaping honey bee immune and behavioral responses to Vairimorpha and support subspecies-targeted breeding and disease management strategies to enhance resilience.