Does the eclipse limit bacterial nucleoid complexity and cell width?

Cell size of bacteria is related to 3 temporal parameters: chromosome replication time , period from replication-termination to subsequent division , and doubling time . Steady-state, bacillary cells grow exponentially by extending length only, but their constant width is larger at shorter 's or longer 's, in proportion to the number of chromosome replication positions (= /), at least in and . Extending by of result in continuous increase of , associated with rising , up to a limit before branching. A set of such puzzling observations is qualitatively consistent with the view that the actual cell mass (or volume) at the time of replication-initiation (or ), usually relatively constant in growth at varying 's, rises with time under thymine limitation of fast-growing, thymine-requiring strains. The hypothesis will be tested that presumes existence of a minimal distance between successive moving replisomes, translated into the time needed for a replisome to reach before a new replication-initiation at is allowed, termed Eclipse . Preliminary analysis of currently available data is inconsistent with a constant under all conditions, hence other explanations and ways to test them are proposed in an attempt to elucidate these and other results. The complex hypothesis takes into account much of what is currently known about Bacterial Physiology: the relationships between cell dimensions, growth and cycle parameters, particularly nucleoid structure, replication and position, and the mode of peptidoglycan biosynthesis. Further experiments are mentioned that are necessary to test the discussed ideas and hypotheses.