A Multiscale Analysis of Bacterial Predation

ended

Predation arguably impacts the evolution and shape of ecological systems. This process occurs at all scales from mammals to viruses. Predatory bacteria remain poorly studied despite their biological importance and often versatile experimental tractability. In this project, we propose to remedy this gap and study the molecular, cellular and ecological aspects of a collective bacterial predatory behavior. Specifically, capitalizing from previous molecular studies on motility, we will investigate how Myxococcus xanthus invades prey colonies and directly feeds on the prey cells by contact-dependent killing. We will then explore how the Myxococcus cells disseminate throughout the prey colony as concerted waves, thus preparing the next predatory cycle. While these experiments will be conducted in laboratory context, we will link molecular mechanisms of predation to ecological dynamics that actually occur in the wild directly by genomic analyses of environmental isolates and experimental evolution of predator-prey interactions. The feasibility of the project is guaranteed by the development of a new imaging tool (Bacto-Hubble) that captures the entire predatory cycle at single cell resolution. In addition, our laboratory recently identified for the first time the Myxococcus genes that promote contact-dependent killing, paving to molecular studies of prey killing and consumption. This project is uniquely multiscale and its realization requires true interdisciplinarity. For this, we will assemble a large collaborative network to connect approaches from the realms of genetics, structural biochemistry, theory and modeling and large-scale genomics. At the end of the project, we expect to obtain a first spatially resolved molecular blueprint of the Myxococcus predatory cycle, which will provide a framework to understand other multicellular predatory processes and well as their evolutionary trajectories.