Research Starter Grant

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A research starter grant has been awarded to Dr. Scott R. Miller of The University of Montana to assist the PI's establishment of an independent research program in microbial ecology and evolution. This award will enable the PI to procure materials and supplies required to build upon previously supported investigations that address key issues regarding the origins and distribution of microbial diversity in nature. Population genetic, physiological and field ecological approaches will be integrated in order to test ideas about how genetic and physiological variation is distributed within and among isolated microbial populations, using the cyanobacterium Mastigocladus, found worldwide in geographically disparate hot spring "island" habitats, as a natural experimental system. Three specific projects will be completed: (1) DNA sequence data collected for several metabolic genes from Mastigocladus laboratory isolates collected from around the world will be analyzed by recently developed genealogical methods in order to evaluate the respective roles of localized natural selection on specific metabolic pathways, geographic barriers to migration, and genetic recombination in shaping Mastigocladus diversity; (2) physiological experiments will be used to determine the ecological differences that distinguish the six major evolutionary "tribes" of Mastigocladus identified in previous studies; (3) the hypothesized association between environmental temperature and genetic variation of Mastigocladus within a population will be tested along a well-studied hot spring thermal gradient by analyzing patterns of DNA sequence data collected from cells growing at different temperatures.Understanding the evolutionary, demographic and geographical factors that shape the distribution of microbial diversity on the planet is a key goal of microbial ecology. By taking a combination of approaches to explicitly address the contributions of natural selection, chance and geography to the global patterns of genetic and ecological diversity in Mastigocladus, this study will provide new insights into the origins of the diversity of microorganisms and how that diversity moves from one place to another.