Quantifying the Biophysical Impact of Budding Cell Division on the Spatial Organization of Growing Yeast Colonies

Spatial patterns in microbial colonies are the consequence of cell-division dynamics coupled with cell-cell interactions on a physical media. Agent-based models (ABMs) are a powerful tool for understanding the emergence of large scale structure from individual cell processes. In particular, the yeast, mph{Saccharomyces cerevisiae}, is a model eukaryote which commonly undergoes an asymmetric division process called budding. In this work, we develop and analyze an ABM to study the impact of budding cell division on yeast colony structure. We find that while large-scale properties of the colony (such as shape and size) are preserved, local spatial organization of the colony, with respect to mother-daughter relationships, subcolonies and their connectivities, are greatly impacted. This difference in spatial organization, coupled with differential growth rates from nutrient limitation, create distinct sectoring patterns in the subcolony structure, which offers novel insights into mechanisms driving experimentally observed sectored yeast colony phenotypes. Moreover, our work illustrates the need to include relevant biophysical mechanisms when using ABMs to compare to experimental studies.