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bioRxiv · 10.1101/2021.07.29.454238

Cellular organization in lab-evolved and extant multicellular species obeys a maximum entropy law

Day, T. C.·Höhn, S. S.·Zamani-Dahaj, S. A.·Yanni, D.·Burnetti, A.·Pentz, J.·Honerkamp-Smith, A. R.·Wioland, H.·Sleath, H. R.·Ratcliff, W. C.·Goldstein, R. E.·Yunker, P. J.
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Abstract

The prevalence of multicellular organisms is due in part to their ability to form complex structures. How cells pack in these structures is a fundamental biophysical issue, underlying their functional properties. However, much remains unknown about how cell packing geometries arise, and how they are affected by random noise during growth - especially absent developmental programs. Here, we quantify the statistics of cellular neighborhoods of two different multicellular eukaryotes: lab-evolved "snowflake" yeast and the green alga Volvox carteri. We find that despite large differences in cellular organization, the free space associated with individual cells in both organisms closely fits a modified gamma distribution, consistent with maximum entropy predictions originally developed for granular materials. This entropic cellular packing ensures a degree of predictability despite noise, facilitating parent-offspring fidelity even in the absence of developmental regulation. Together with simulations of diverse growth morphologies, these results suggest that gamma-distributed cell neighborhood sizes are a general feature of multicellularity, arising from conserved statistics of cellular packing.

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Day, T. C., Höhn, S. S., Zamani-Dahaj, S. A., Yanni, D., Burnetti, A., Pentz, J., Honerkamp-Smith, A. R., Wioland, H., Sleath, H. R., Ratcliff, W. C., Goldstein, R. E., Yunker, P. J.. 2021-07-29. Cellular organization in lab-evolved and extant multicellular species obeys a maximum entropy law. https://doi.org/10.1101/2021.07.29.454238

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