Our laboratory is part of the Microbial Sciences Institute at the Yale West Campus. Our group studies the temporal and spatial mechanisms involved in bacterial physiology, with emphasis on chromosome dynamics, cell division, cell cycle regulation, cell morphogenesis and RNA biology. Our primary model organisms are Caulobacter crescentusEscherichia coli and the Lyme disease pathogen Borrelia burgdorferi.

Cellular life cannot be sustained and propagated without temporal and spatial organization. Even bacteria, once mistakenly perceived as tiny jumbles of molecules, rely on temporal and spatial organization for many essential processes. In recent years, we have come to realize that bacteria are polarized, possess a cytoskeleton, order their chromosomes in space, localize proteins, and depend critically on this surprisingly exquisite cellular organization. Despite the recent surge of information about bacterial cell biology, our knowledge is still at an early stage and the most fundamental questions remain to be solved, providing unique opportunities to make new and exciting discoveries in this emerging discipline.

Our laboratory addresses the molecular mechanisms involved in the internal organization of bacteria at several levels, from its origin, maintenance and replication in time and space to its function in cellular physiology and morphogenesis. We used two primary model systems: E. coli and C. crescentus, each having distinct advantages. On one hand, there is a wealth of knowledge on E. coli and studies are facilitated by the availability of large collections of strains, tools and databases. On the other hand, the highly polarized dimorphic C. crescentus provides a unique set of strengths for addressing questions pertinent to positional and temporal information. Cellular asymmetry is morphologically apparent in C. crescentus by the presence of polar appendages (e.g., stalk, pili and flagellum), and by the obligatory asymmetric division that yields daughter cells of different size, fate and morphology. Populations of C. crescentus cells can be easily synchronized with respect to the cell cycle, providing a means to follow events during the cell cycle. This bacterium also displays a sophisticated morphology and it possesses all three major types of cytoskeletal elements, MreB (actin homolog), FtsZ (tubulin homolog) and crescentin (intermediate filament-like protein).

For our studies, we use an arsenal of genetic, biochemical, bioinformatic and cell imaging tools. A large part of our current strategy is to improve the inventory of components involved in cellular organization, characterize the function and interplay of known components, evolve our work into quantitative studies and computational modeling, and develop methodology to generate new hypotheses and avenues of research.