Student Information

Many species of solitary bee harbour bacterial endosymbionts from the genus Wolbachia. This symbiont may have many different effects on its host, however its role in bees is almost entirely unclear. This project will test if Wolbachia may provide nutrients that the bees cannot get in sufficient quantities from their pollen sources. A special focus will be specialised bees that only collect pollen from a single or few very closely related plant species. The fieldwork in this project involves sampling of pollen from several different plant species. These will be analysed in the lab with regards to their nutrient composition, e.g., via ELISA and/or HPLC. Based on literature data on pollen preferences of bees, the project will then test if the presence of Wolbachia is linked to the deficiency of nutirents in some pollen types.

More than half of all insect species harbour intracellular bacterial symbionts that are transmitted from mothers to their offspring. In the vast majority of cases, the impact of the symbionts on their hosts is unknown. In addition, the diversity of endosymbionts in some regions is largely unknown. In this project, the diversity of bacterial endosymbionts of insects from different Neotropical countries will be characterised and compared with that of insects from Europe. The methodology for this project includes molecular genetic methods (DNA extractions, PCRs), latest sequencing technologies (Oxford Nanopore) and some bioinformatics.

Many insects harbour bacterial symbionts in their cells, which can perform a variety of functions. This project will investigate bacteria that protect the fruit fly Drosophila melanogaster from attacks by parasitic wasps. As this is detrimental to the reproductive success of the wasp, it would be expected that the wasp would evolve strategies to circumvent the protective function of the endosymbionts. The first step is to test whether parasitic wasps can detect the presence of protective endosymbionts at all. The second step is to test whether symbionts influence the ‘odour’ of their hosts and thus reveal their presence. The project includes behavioural experiments and gas chromatic characterisation of cuticular hydrocarbons of Drosophila.

Spiroplasma is a common intracellular endosymbiont of Drosophila (fruit flies) and many other insects. Key to the interaction of the symbiont with its hosts are spiralins, a class of surface proteins. In this project, the diversity of spiralins in different Spiroplasma strains will be analysed and their evolutionary origin clarified. In addition, the extent to which recombination and horizontal gene transfer characterise the evolution of these proteins and which other mobile elements (plasmids, phages) may contribute to this will be investigated. This is a purely genomic/bioinformatics project based on published and unpublished data.