Ecology and evolution of the bumblebee gut microbiota
This is the PhD project of Sarah Walkington, funded by a NERC Industrial Case studentsip. It is a collaboration with Matt Heard (project leader) and Chris van der Gast at CEH, and Felix Wäckers and Annette Van Oystaeyen at Biobest.
Communities of microorganisms (microbiota) that colonize animal hosts are ubiquitous in nature and play important roles in digestion and immune defence. Understanding their ecology and evolution is a novel and rapidly emerging area of science largely facilitated by technological advances in molecular biology. Researchers are increasingly aware of the important role that interactions between different elements of the microbiota (both commensal microorganisms and pathogens), host immunity and the environment play in determining host health. However, to date most studies have focused on the microbiota found within the human gut. We lack a good understanding of the of gut microbiota of many wild species that provide important ecosystem services such as pollination.
Recent studies of the bumblebee gut microbiota have revealed apparently highly specific bacterial communities. It is likely that these play a role in immune defence and digestive efficiency and may be particularly important in determining overall fitness. However, little is known about the ecology of these bacteria at the colony level or how environmental factors affect their transmission, community assembly and efficacy. Understanding the role that the gut microbiota plays in bumblebee ecology may thus have wide-reaching implications for our understanding of their basic biology and for current practices in breeding, conservation, and agriculture.
We are asking four main questions in this research:
1. What are the diversity, abundance and distribution of bacterial gut microbiota through wild type and cultured subspecies of Bombus terrestris?
2. How do changes in foraging behaviour and access to different food sources affect the gut microbiota?
3. What are the relative contributions of vertical (flower to bee) vs. horizontal (between nest mates) transmission to gut microbiota assembly and how are these influenced by environmental factors?
4. What protection does the gut microbiota give bees against challenges from widely-used pesticides, e.g.,neonicotinoids, and common high impact microparasites e.g. Crithidia bombi and Nosema bombi?