Dr. Alexander Bergman

Research interests

•    Host-virus interactions in insects
•    Ecology of viruses, hosts, and vectors
•    Genetics of immunity, virulence, and adaptation
 

Scientific Projects

As a vector biologist, my main interest lies in understanding how viruses integrate their transmission cycles into the ecology and physiology of their insect hosts. My research is based on in vivo infection experiments with molecular and phenotypic readouts as well as transcriptomics and population genetics.

Ongoing projects

The role of heat shock proteins in antiviral defense in bees
This project aims to investigate the molecular interactions between heat shock proteins and RNA interference in honey and bumble bees. We hypothesize that heat shock proteins stabilize the RNA-induced silencing complex, leading to a more potent immune response against infecting viruses. Using deformed wing virus (DWV) as a model, we will determine how heat shock affects viral replication and corroborate our findings with RNAi pathway activity. This will inform us not only on the nuanced effects of climate change on bee physiology and virus transmission but also provide potential targets for gene therapy against the damage caused by emerging viruses in bee husbandry.
Transposable elements (TEs) in honey bee adaptation and genetic diversity
While TEs are a major source of mutations, contributing to large chromosomal rearrangements and altered patterns of gene expression, the TE landscape of bees remains poorly characterized. This project aims to identify TE insertion polymorphisms in distinct populations of honey bees and verify their effects on the transcriptome and consequent phenotype. These findings will allow us to infer the genetic plasticity and rate of TE turnover in managed bees, as well as ecological and physiological factors that may trigger TE reactivation.

Planned projects

Adaptation of deformed wing virus to vector-borne Transmission

The virulence-transmission trade-off hypothesis, i.e., that vector-borne pathogens exhibit greater virulence as they are less dependent on host fitness for their transmission, is supported by observations but lacks empirical evidence. Deformed wing virus (DWV) – currently transitioning from direct transmission between honey bees to being vectored by the parasitic Varroa mite between pupae – thus presents a unique natural experiment that can refute or corroborate this hypothesis. By comparing DWV from locations with different dominant modes of transmission, we can identify segregating mutations and verify their effects on viral replication and host fitness across life stages and tissues. By studying the differences in the host immune response, we can further determine the mechanisms through which viruses can change their virulence profile in their transition to vector-borne transmission.
 

Future students

I am always happy to welcome students for shorter and longer projects in molecular biology, immunology, virology, and/or bioinformatics. Feel free to contact me so that we can discuss how our interests align and how we can incorporate them into an independent study, fitting within the greater framework of our ongoing and planned research. For the moment, I can only offer supervision in English.

Selected publications

Bergman, A., Crist, A.B., Lopez-Maestre, H., Blanc, H., Castelló-Sanjuán, M., Frangeul, L., Varet, H., Merkling, S.H., Saleh, M.-C., & Lambrechts, L. Limited impact of the siRNA pathway on transposable element expression in Aedes aegypti. BMC Biology 23, 130 (2025). doi.org/10.1186/s12915-025-02225-8 

Merkling, S.H., Crist, A.B., Henrion-Lacritick, A., Frangeul, L., Couderc, E., Gausson, V., Blanc, H., Bergman, A., Baidaliuk, A., Romoli, A., Saleh, M.-C., Lambrechts, L. Multifaceted contributions of Dicer2 to arbovirus transmission by Aedes aegypti. Cell Reports 42, 112977 (2023). doi.org/10.1016/j.celrep.2023.112977 

Bergman A., & Hesson, J.C. Wolbachia prevalence in the vector species Culex pipiens and Culex torrentium in a Sindbis virus-endemic region of Sweden. Parasites & Vectors 14, 428 (2021). doi.org/10.1186/s13071-021-04937-6 

Bergman, A., Dahl, E., Lundkvist, Å., & Hesson, J.C. Sindbis Virus Infection in NonBlood-Fed Hibernating Culex pipiens Mosquitoes in Sweden. Viruses 12(12), 1441 (2020). doi.org/10.3390/v12121441