Molecular profiling of bark beetle mycobiota

• Main Author: Miller, Kirsten Eleanor
• Other Authors: Vogler, Alfried
• Published: Imperial College London 2015
• Subjects: 595.76
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.712863

No organism evolves in isolation; the symbiotic microorganisms associated with insects are key determinants of their hosts ecology and evolution. This thesis investigates the fungal communities found with bark and ambrosia beetles (Curculionidae: Scolytinae & Platypodinae) in an attempt to better understand the diversity and variability of this ecologically and economically important system. I start by assessing the efficacy of high throughput sequencing (HTS) and metabarcoding for the characterisation of fungal communities derived from whole arthropod DNA extracts (Chapter 2). I then apply this approach to understanding the biotic and abiotic determinants of beetle associated fungal taxa, and find that both beetle species identity and environmental conditions significantly predict community richness and composition (Chapter 3). In Chapter 4, I expand upon the beetle species level differences in microbial communities to show that they are driven by a relatively small subset of fungal taxa, predominantly belonging to the beetle associated Microascales, but also to the relatively unexplored Saccharomycetes. I further apply HTS to the recreation of beetle evolutionary histories using mitochondrial genomics, and test for correlations between beetle phylogenetic and mycobiotic similarities (Chapter 5). My investigations demonstrate the utility of recently developed sequencing technologies to the study of microbial symbioses and I conclude with a synthetic summary of my findings with suggestions for further research.