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Bozdag GO, Zamani-Dahaj SA, Day TC, Kahn PC, Burnetti AJ, Lac DT, Tong K, Conlin PL, Balwani AH, Dyer EL, Yunker PJ, Ratcliff WC. De novo evolution of macroscopic multicellularity. Nature 2023; 617:747-754. [PMID: 37165189 PMCID: PMC10425966 DOI: 10.1038/s41586-023-06052-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 04/05/2023] [Indexed: 05/12/2023]
Abstract
While early multicellular lineages necessarily started out as relatively simple groups of cells, little is known about how they became Darwinian entities capable of sustained multicellular evolution1-3. Here we investigate this with a multicellularity long-term evolution experiment, selecting for larger group size in the snowflake yeast (Saccharomyces cerevisiae) model system. Given the historical importance of oxygen limitation4, our ongoing experiment consists of three metabolic treatments5-anaerobic, obligately aerobic and mixotrophic yeast. After 600 rounds of selection, snowflake yeast in the anaerobic treatment group evolved to be macroscopic, becoming around 2 × 104 times larger (approximately mm scale) and about 104-fold more biophysically tough, while retaining a clonal multicellular life cycle. This occurred through biophysical adaptation-evolution of increasingly elongate cells that initially reduced the strain of cellular packing and then facilitated branch entanglements that enabled groups of cells to stay together even after many cellular bonds fracture. By contrast, snowflake yeast competing for low oxygen5 remained microscopic, evolving to be only around sixfold larger, underscoring the critical role of oxygen levels in the evolution of multicellular size. Together, this research provides unique insights into an ongoing evolutionary transition in individuality, showing how simple groups of cells overcome fundamental biophysical limitations through gradual, yet sustained, multicellular evolution.
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Affiliation(s)
- G Ozan Bozdag
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
| | - Seyed Alireza Zamani-Dahaj
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
| | - Thomas C Day
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
| | - Penelope C Kahn
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Anthony J Burnetti
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Dung T Lac
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Kai Tong
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Peter L Conlin
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Aishwarya H Balwani
- School of Electrical & Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Eva L Dyer
- School of Electrical & Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Peter J Yunker
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, USA.
| | - William C Ratcliff
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
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