Julian Kiefer

Julian Kiefer

Evolutionary Ecology
Institute of Organismic and Molecular Evolution
Hanns-Dieter-Hüsch-Weg 15
55128 Mainz, Germany

phone: +49 - (0) 6131 - 39 26108

fax: +49 - (0) 6131 - 39 23731



Research Interests

Symbioses between different organisms are omnipresent. Paul Buchner, Anton Koch and later by Alois Huger described already in the 1930s bacterial symbionts within the two beetle families Bostrichidae and Silvanidae. Both revealed that the respective symbiont is not obligate for the host. However, the symbionts support cuticle synthesis and thus prove to be extremely useful as they allow bettles to better adapt to dry conditions, especially in human-made (anthropogenic) habitats. Several pest beetles, including the sawtoothed grain beetles (Oryzaephilus surinamensis), large and lesser grain borers (Prostephanus truncatus and Rhyzopertha dominica), root beetles of the genus Dinoderus and wood beetles of the genus Lyctus became worldwide distributed pests of cereals and other starchy, dry foods and also wood products with support of their bacterial symbionts. Of course, these species occur in humid areas, but their symbionts also allow them, e.g. to survive in the dryness of stored cereal for a long time.

However, it remains still elusive how exactly these symbioses between the beetle and their respective bacterium (or bacteria) functions in detail. As part of my project, I will therefore sequence the genomes of the symbionts of the Bostrichid and Silvanid beetles to analyze their metabolic potential. I also want to know how the host controls its symbionts. One the one hand side it is interesting why they are not attacked and removed by the beetle's immune system, such as pathogenic microorganisms, but are confined to the bacteriomes and don’t spread through the entire beetle body but on the other hand side have to be repeatedly transmitted from bacteriomes to developing eggs through the female body cavity. This, I will take a close look at the transcriptomes of beetles with, beetles without their symbionts, and additionally replace the symbionts by closely related bacteria in various experiments in order to describe their physiological reaction, especially regarding a potential control of the host. I would like to elucidate possible factors of influence by experimental manipulation of candidate genes, e.g. via RNA interference.


Kiefer, J. S. T. et al. (2021) Inhibition of a nutritional endosymbiont by glyphosate abolishes mutualistic benefit on cuticle synthesis in Oryzaephilus surinamensis, Communications Biology 4: 554, DOI: 10.1038/s42003-021-02057-6

Jehn, J., Gebert, D., Pipilescu, F. , Stern, S., Kiefer, J. S. T., Hewel, C. & Rosenkranz, D. (2018) PIWI genes and piRNAs are ubiquitously expressed in mollusks and show patterns of lineage-specific adaptation. - Communications Biology, 1, Article number: 137.

Third-party-funds / grant

2019 GRC-Kongressteilnahme; DAAD-Förderungen für Kongressreisen


Oryzaephilus surinamensis on oat flakes