Exploring Biophysical Constraints on Cell Size Through Massively Parallel Evolution Experiments Utilizing DNA Barcodes
The “growth law” describes an evolutionary constraint, where cell growth rate is often proportional to cell size. However, the general mechanism for this relationship is not fully understood. To approach this problem, we conducted a massively parallel evolution experiment using a barcoded library of over 300,000 unique Saccharomyces cerevisiae isolates, put through a size selection pressure. From there, we were able to uncover unique mutations associated with changes in cell size. Our work allowed us to analyze if changes in size and mass are associated with changes in growth rate from both an individual cell and population level. Our work shows no significant correlation present between size and growth rate following the size selection evolution. However, our work suggests potential relationships between cell size and cell density. In this seminar, I will discuss these findings as well as our plans to further develop barcode technologies to allow deeper exploration of the mutations underlying phenotypes of interest.