Cell Curvature May Enhance Division in Caulobacter crescentus

Abstract

The prokaryotic kingdom exhibits an extraordinary range of cell shapes and morphologies. Although we know what shapes different bacterial species assume and how some species maintain these shapes, the question of why bacteria are shaped the way they are has not yet been answered. The specific morphology of each prokaryotic species is conserved across evolution, which suggests that a functional and selective advantage of each cell shape exists for each bacterium that assumes it. One cell shape that is common among bacteria, especially in species that live in aqueous environments, is that of the curved rod. Although these vibrioid cells represent a significant proportion of prokaryotic species, very little is known about the benefits their shape provides them. Using Caulobacter crescentus as our model organism, we show the potential involvement of cell curvature in successful cell division in standing cultures. We hypothesize that the curvature provides the force necessary to fully separate daughter cells in force-free environments. While we suggest that further experiments be conducted to confirm this theory, we demonstrate here a potential selective advantage of the curved shape in C. crescentus.