TY - JOUR
T1 - Population genetics in microchannels
AU - Koldaeva, Anzhelika
AU - Tsai, Hsieh Fu
AU - Shen, Amy Q.
AU - Pigolotti, Simone
N1 - Funding Information:
ACKNOWLEDGMENTS. We acknowledge the support of the Okinawa Institute of Science and Technology Graduate University (OIST) with subsidy funding from the Cabinet Office, Government of Japan. We are grateful for the help and support provided by the Scientific Computing and Data Analysis section of the Research Support Division at OIST. We thank colleagues from the Micro/Bio/Nanofluidics Unit at OIST: Daniel Carlson for assistance in numerical simulation and Riccardo Funari for fruitful discussion; Professor Paola Laurino from OIST for gifting the MG1655 strain and Dr. Pamela Silver from Harvard University for gifting the pUA66 PrpsL-GFP plasmid; and Deepak Bhat, Massimo Cencini, Kirill Korolev, and Robert Ross for feedback on a preliminary version of the manuscript.
Publisher Copyright:
Copyright © 2022 the Author(s).
PY - 2022/3/22
Y1 - 2022/3/22
N2 - Spatial constraints, such as rigid barriers, affect the dynamics of cell populations, potentially altering the course of natural evolution. In this paper, we investigate the population genetics of Escherichia coli proliferating in microchannels with open ends. Our analysis is based on a population model, in which reproducing cells shift entire lanes of cells toward the open ends of the channel. The model predicts that diversity is lost very rapidly within lanes but at a much slower pace among lanes. As a consequence, two mixed, neutral E. coli strains competing in a microchannel must organize into an ordered regular stripe pattern in the course of a few generations. These predictions are in quantitative agreement with our experiments. We also demonstrate that random mutations appearing in the middle of the channel are much more likely to reach fixation than those occurring elsewhere. Our results illustrate fundamental mechanisms of microbial evolution in spatially confined space.
AB - Spatial constraints, such as rigid barriers, affect the dynamics of cell populations, potentially altering the course of natural evolution. In this paper, we investigate the population genetics of Escherichia coli proliferating in microchannels with open ends. Our analysis is based on a population model, in which reproducing cells shift entire lanes of cells toward the open ends of the channel. The model predicts that diversity is lost very rapidly within lanes but at a much slower pace among lanes. As a consequence, two mixed, neutral E. coli strains competing in a microchannel must organize into an ordered regular stripe pattern in the course of a few generations. These predictions are in quantitative agreement with our experiments. We also demonstrate that random mutations appearing in the middle of the channel are much more likely to reach fixation than those occurring elsewhere. Our results illustrate fundamental mechanisms of microbial evolution in spatially confined space.
KW - Bacterial evolution
KW - Individual-based models
KW - Microfluidics
KW - Spatial population dynamics
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U2 - 10.1073/pnas.2120821119
DO - 10.1073/pnas.2120821119
M3 - Article
C2 - 35302890
AN - SCOPUS:85126696797
VL - 119
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 12
M1 - e2120821119
ER -