Effects of host microbiome on thermal tolerance in Drosophila melanogaster

Master thesis project, 60 ECTS

Project description

Microbiomes are increasingly being recognized as drivers of selection and adaptation (Rudman et al., 2019). Recent studies have also found that host genetic selection for thermal tolerance can influence the composition of the microbiome (Kokou et al., 2018). Thus, it is evident that the relationship between hosts and microbiomes is a two-way interaction, and that manipulating one factor can have a fitness consequence in the other. Insect microbiome strongly responds to seasonal shifts in temperature in Gryllus veletis with implications for cold tolerance and immune responses (Ferguson et al., 2018). Experimental manipulation of developmental temperature also resulted in a shift in microbial composition and is correlated with thermal tolerance in D. melanogaster (Moghadam et al., 2018). Thus, we hypothesize that the responses to fluctuating temperatures in D. melanogaster and microbial composition could be uniquely related.

To test this hypothesis, the project will perform metatranscriptomic analyses comparing differences in the microbial composition between flies acclimated to fluctuating temperatures (19 ± 8 °C) and those acclimated to a constant temperature (19 ± 0 °C). Additionally, the project will also interrogate the differences in host microbiome between developmental and adult life stages in this species. We have already generated both transcriptional and phenotypic data for this project, showing altered gene expression signatures between the two acclimation groups which could partly enable the differences in heat tolerance that we observe between constant and fluctuating temperature acclimated flies of this species (Salachan & Sørensen, 2022). The candidate will make use of this wealth of data to drive the research further, using publicly available bioinformatic tools. The ideal student will thus have some experience with programming (e.g. in R) or a keen interest to develop their bioinformatic skills, under supervision.

For further information contact:

Jesper Givskov Sørensen, Genetics, Ecology and Evolution: jesper.soerensen@bio.au.dk


                      Ferguson, L. V., Dhakal, P., Lebenzon, J. E., Heinrichs, D. E., Bucking, C., Sinclair, B. J. and Barribeau, S. (2018). Seasonal shifts in the insect gut microbiome are concurrent with changes in cold tolerance and immunity. Functional Ecology 32, 2357-2368.  doi. 10.1111/1365-2435.13153

                      Kokou, F., Sasson, G., Nitzan, T., Doron-Faigenboim, A., Harpaz, S., Cnaani, A. and Mizrahi, I. (2018). Host genetic selection for cold tolerance shapes microbiome composition and modulates its response to temperature. Elife 7.  doi. 10.7554/eLife.36398

                      Moghadam, N. N., Thorshauge, P. M., Kristensen, T. N., de Jonge, N., Bahrndorff, S., Kjeldal, H. and Nielsen, J. L. (2018). Strong responses of Drosophila melanogaster microbiota to developmental temperature. Fly (Austin) 12, 1-12.  doi. 10.1080/19336934.2017.1394558

                      Rudman, S. M., Greenblum, S., Hughes, R. C., Rajpurohit, S., Kiratli, O., Lowder, D. B., Lemmon, S. G., Petrov, D. A., Chaston, J. M. and Schmidt, P. (2019). Microbiome composition shapes rapid genomic adaptation of Drosophila melanogaster. Proceedings of the National Academy of Sciences 116, 20025-20032.  doi. 10.1073/pnas.1907787116

Salachan, P. V. and Sørensen, J. G. (2022). Molecular mechanisms underlying plasticity in a thermally varying environment, Molecular Ecology, 31:3174–3191. doi: 10.1111/mec.16463.