Bacteria capable of developing from vegetative cells into spores are responsible for many phenomena with profound influences on environmental and human health, from nutrient cycling to infecting agricultural pests to killing humans. Although these bacteria are ubiquitous in nature, we know little about the relative amount of time they spend as metabolically active cells versus dormant spores. Quantifying the relative importance of these life stages has implications for understanding the evolution of phenotypic plasticity, the dispersal and infectivity of pathogens, and the poorly understood ecology of bacteria.
Previous attempts to address questions regarding spore dormancy in nature have used laboratory culture techniques, which inevitably bias the results towards those species able to grow in culture. Laboratory culture studies also usually ignore the polymicrobial aspect of bacterial existence in nature, thereby missing an important driver of microbial ecology and evolution. Luckily, technological advances are now allowing the in situ examination of bacterial activity through the reading of nucleic acids.
My research plans to use environmental RNA sequencing (metatranscriptomic) datasets to examine where and when sporulation initiation genes are transcribed, to effectively measure the entrance into the sporulation phase of the life cycle. Similar data will be used to determine when spores become metabolically active cells again, by examining the transcription of germination genes. Comparative analysis of whole genome (or metagenome) sequence data will enable close examination of the evolution of sporulation and germination genes in a diverse set of spore-forming bacteria, to make inferences regarding their importance for bacterial survival. These datasets can also be used to trace the origin of sporulation functions in many genes shared between spore-forming and non-spore-forming bacteria.
For more information, including my budding writing and consulting business, see http://www.heathermaughan.ca