Abstract

The engineering of multicellular systems could exploit the advantages of spatial organization and cellular differentiation. It could also expand the range of information processing capabilities using simple distributed and coupled responses to produce complex outputs. Our work uses bacterial colonies and biofilms as simple multicellular systems, with the aim of transferring these morphogenetic principles into plants. I will talk about two of our current projects in bacteria (in collaboration with Paul Steiner and Tim Rudge), and also some of our work with plant systems:

1. Fractal-like patterns and physical self-organization in large bacterial population

TR and PJS have developed fast, large-scale biophysical and genetic modeling tools for simulating biofilms. Using these tools we have revealed emergent properties of cell-shape that give rise to self-similar fractal-like morphology in biofilms, and confirmed this with high resolution confocal microscopy. I will present these results, and show how this approach can inform engineering of multicellular systems, including extension to plant biophysics.

2. Synthetic segmentation

Using principles from developmental biology, we are designing bacterial transcription networks that will divide a biofilm into segments of distinct gene expression in response to a gradient. We are combining ratiometric characterization of parts (developed in collaboration with James Brown) with high- throughput computational modeling to evaluate attainable regions of network space. This work has highlighted natural motifs, and novel circuits that will be useful in engineering complex multicellular behavior. We will also talk about regulatory elements that we are developing to build such systems in plants and a novel technique for their characterization.