Dr. Chisholm will investigate fundamental aspects of growth regulation and dynamics of marine plankton in the fluctuating environments that are typical of oceanic regimes. This understanding is essential for modelling and designing studies of marine productivity and food web dynamics. Specifically, they will: * Study the diatom life cycle, to better understand what environmental and genetic factors control the switch from vegetative to sexual reproduction; * Investigate the cell cycle in cyanobacteria and marine bacteria, to better understand how their DNA cycle is regulated under changing growth conditions, and why aspects of the cycle deviate from the classic E. coli model; * Develop a multichannel, high-sensitivity (and relatively inexpensive) flow cytometer, which will facilitate the study small picoplankton and marine bacteria. The results of this work will augment our understanding of microbial growth rates in the sea and phytoplankton population genetics; it should also contribute methodological advances for the study of marine bacteria at sea. Moreover, it could enhance our fundamental understanding of microbial physiology by revealing features of marine organisms which deviate from classical paradigms.
