Honey bee egg composition changes seasonally and after acute maternal virus infection

Authors: CHAPMAN, ABIGAIL - University Of British Columbia; MCAFEE, ALISON - University Of British Columbia; WRIGHTSON, KENZIE - University Of British Columbia; ALCAZAR, ARMANDO - University Of British Columbia; TARPY, DAVID - North Carolina State University; Fine, Julia; REMPEL, ZOE - University Of Manitoba; PETERS, KIRA - University Of Manitoba; CURRIE, ROB - University Of Manitoba; HOOVER, SHELLEY - University Of Lethbridge; FOSTER, LEONARD - University Of British Columbia

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/16/2025
Publication Date: 3/26/2025
Citation: Chapman, A., Mcafee, A., Wrightson, K., Alcazar, A., Tarpy, D.R., Fine, J.D., Rempel, Z., Peters, K., Currie, R., Hoover, S., Foster, L.J. 2025. Honey bee egg composition changes seasonally and after acute maternal virus infection. Scientific Reports. 15. Article 10418. https://doi.org/10.1038/s41598-025-94670-2.
DOI: https://doi.org/10.1038/s41598-025-94670-2

Interpretive Summary: Honey bee colonies depend on the reproductive output of their queens, which in turn depends on the care provided to her by worker bees. Viral infections in queens can compromise reproductive output, while worker infections can inhibit the successful functioning of a colony and their ability to care for the queen. Transgenerational immune priming (TGIP) occurs when queens transfer immune-related compounds or immune elicitors to their offspring, enhancing their offspring’s ability to resist infections. These maternal effects on offspring could positively impact colony health and resilience to viral infections, but little is currently known about TGIP for viruses. In this study, we investigate how viral infections affect the protein composition of eggs laid by viral immune-challenged queens (injected with a mixture of BQCV and DWV-B), both in controlled experimental settings and in natural field conditions. Our results showed that immune-challenged queens upregulated immune effectors in their eggs and ovaries. In contrast, naturally infected queens from field surveys did not show significant differences in egg protein, lipid, or metabolite composition related to maternal viral load or ovary size. However, the date of egg collection strongly influenced egg composition, likely reflecting seasonal variations in pollen resources. These findings highlight that while viral infections can induce transgenerational effects on egg proteomes under short-term experimental conditions, such effects are less apparent in natural settings and can be overshadowed by seasonal and other ecological factors.

Technical Abstract: Honey bee (Apis mellifera) colonies depend on the reproductive output of their queens, which in turn is contingent on the care provided by worker bees. Viral infections in queens can compromise reproductive output, while worker infections can inhibit the successful functioning of a colony and their ability to care for the queen. Transgenerational immune priming (TGIP) occurs when queens transfer immune-related compounds or immune elicitors to their offspring, enhancing the ability of subsequent generations to resist infections. These maternal effects on offspring could positively impact colony health and resilience to viral infections, but little is currently known about TGIP for viruses. In this study, we investigate how viral infections affect the proteomic composition of eggs laid by viral immune-challenged queens (injected with a mixture of BQCV and DWV-B), both in controlled experimental settings and in natural field conditions. Our results showed that immune-challenged queens upregulated immune effectors in their eggs and ovaries. In contrast, naturally infected queens from field surveys did not show significant differences in egg protein, lipid, or metabolite composition related to maternal viral load or ovary size. However, the date of egg collection strongly influenced egg composition, likely reflecting seasonal variations in pollen resources. These findings highlight that while viral infections can induce transgenerational effects on egg proteomes under short-term experimental conditions, such effects are less apparent in natural settings and can be overshadowed by seasonal and other ecological factors.