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Oszoli I, Zachar I. Group-selection via aggregative propagule-formation enables cooperative multicellularity in an individual based, spatial model. PLoS Comput Biol 2024; 20:e1012107. [PMID: 38713735 PMCID: PMC11101088 DOI: 10.1371/journal.pcbi.1012107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 05/17/2024] [Accepted: 04/24/2024] [Indexed: 05/09/2024] Open
Abstract
The emergence of multicellularity is one of the major transitions in evolution that happened multiple times independently. During aggregative multicellularity, genetically potentially unrelated lineages cooperate to form transient multicellular groups. Unlike clonal multicellularity, aggregative multicellular organisms do not rely on kin selection instead other mechanisms maintain cooperation against cheater phenotypes that benefit from cooperators but do not contribute to groups. Spatiality with limited diffusion can facilitate group selection, as interactions among individuals are restricted to local neighbourhoods only. Selection for larger size (e.g. avoiding predation) may facilitate the emergence of aggregation, though it is unknown, whether and how much role such selection played during the evolution of aggregative multicellularity. We have investigated the effect of spatiality and the necessity of predation on the stability of aggregative multicellularity via individual-based modelling on the ecological timescale. We have examined whether aggregation facilitates the survival of cooperators in a temporally heterogeneous environment against cheaters, where only a subset of the population is allowed to periodically colonize a new, resource-rich habitat. Cooperators constitutively produce adhesive molecules to promote aggregation and propagule-formation while cheaters spare this expense to grow faster but cannot aggregate on their own, hence depending on cooperators for long-term survival. We have compared different population-level reproduction modes with and without individual selection (predation) to evaluate the different hypotheses. In a temporally homogeneous environment without propagule-based colonization, cheaters always win. Predation can benefit cooperators, but it is not enough to maintain the necessary cooperator amount in successive dispersals, either randomly or by fragmentation. Aggregation-based propagation however can ensure the adequate ratio of cooperators-to-cheaters in the propagule and is sufficient to do so even without predation. Spatiality combined with temporal heterogeneity helps cooperators via group selection, thus facilitating aggregative multicellularity. External stress selecting for larger size (e.g. predation) may facilitate aggregation, however, according to our results, it is neither necessary nor sufficient for aggregative multicellularity to be maintained when there is effective group-selection.
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Affiliation(s)
- István Oszoli
- Department of Plant Systematics, Ecology and Theoretical Biology, Eötvös Loránd University, Budapest, Hungary
| | - István Zachar
- Department of Plant Systematics, Ecology and Theoretical Biology, Eötvös Loránd University, Budapest, Hungary
- HUN-REN Institute of Evolution, Centre for Ecological Research, Budapest, Hungary
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Vroomans RMA, Colizzi ES. Evolution of selfish multicellularity: collective organisation of individual spatio-temporal regulatory strategies. BMC Ecol Evol 2023; 23:35. [PMID: 37468829 PMCID: PMC10357660 DOI: 10.1186/s12862-023-02133-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 06/12/2023] [Indexed: 07/21/2023] Open
Abstract
BACKGROUND The unicellular ancestors of modern-day multicellular organisms were remarkably complex. They had an extensive set of regulatory and signalling genes, an intricate life cycle and could change their behaviour in response to environmental changes. At the transition to multicellularity, some of these behaviours were co-opted to organise the development of the nascent multicellular organism. Here, we focus on the transition to multicellularity before the evolution of stable cell differentiation, to reveal how the emergence of clusters affects the evolution of cell behaviour. RESULTS We construct a computational model of a population of cells that can evolve the regulation of their behavioural state - either division or migration - and study both a unicellular and a multicellular context. Cells compete for reproduction and for resources to survive in a seasonally changing environment. We find that the evolution of multicellularity strongly determines the co-evolution of cell behaviour, by altering the competition dynamics between cells. When adhesion cannot evolve, cells compete for survival by rapidly migrating towards resources before dividing. When adhesion evolves, emergent collective migration alleviates the pressure on individual cells to reach resources. This allows individual cells to maximise their own replication. Migrating adhesive clusters display striking patterns of spatio-temporal cell state changes that visually resemble animal development. CONCLUSIONS Our model demonstrates how emergent selection pressures at the onset of multicellularity can drive the evolution of cellular behaviour to give rise to developmental patterns.
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Affiliation(s)
- Renske M A Vroomans
- Informatics Institute, University of Amsterdam, Amsterdam, Netherlands.
- Origins Center, Groningen, Netherlands.
- Sainsbury Laboratory, University of Cambridge, Cambridge, UK.
| | - Enrico Sandro Colizzi
- Origins Center, Groningen, Netherlands
- Sainsbury Laboratory, University of Cambridge, Cambridge, UK
- Mathematical Institute, Leiden University, Leiden, Netherlands
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Forget M, Adiba S, De Monte S. Single-cell phenotypic plasticity modulates social behavior in Dictyostelium discoideum. iScience 2023; 26:106783. [PMID: 37235054 PMCID: PMC10206496 DOI: 10.1016/j.isci.2023.106783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 02/09/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
In Dictyostelium chimeras, "cheaters" are strains that positively bias their contribution to the pool of spores, i.e., the reproductive cells resulting from development. On evolutionary time scales, the selective advantage; thus, gained by cheaters is predicted to undermine collective functions whenever social behaviors are genetically determined. Genotypes; however, are not the sole determinant of spore bias, but the relative role of genetic and plastic differences in evolutionary success is unclear. Here, we study chimeras composed of cells harvested in different phases of population growth. We show that such heterogeneity induces frequency-dependent, plastic variation in spore bias. In genetic chimeras, the magnitude of such variation is not negligible and can even reverse the classification of a strain's social behavior. Our results suggest that differential cell mechanical properties can underpin, through biases emerging during aggregation, a "lottery" in strains' reproductive success that may counter the evolution of cheating.
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Affiliation(s)
- Mathieu Forget
- Institut de Biologie de l’Ecole Normale Supérieure, Département de Biologie, Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France
- Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plőn, Germany
| | - Sandrine Adiba
- Institut de Biologie de l’Ecole Normale Supérieure, Département de Biologie, Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Silvia De Monte
- Institut de Biologie de l’Ecole Normale Supérieure, Département de Biologie, Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France
- Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plőn, Germany
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Rojas-Vega M, de Castro P, Soto R. Wetting dynamics by mixtures of fast and slow self-propelled particles. Phys Rev E 2023; 107:014608. [PMID: 36797971 DOI: 10.1103/physreve.107.014608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 01/06/2023] [Indexed: 01/26/2023]
Abstract
We study active surface wetting using a minimal model of bacteria that takes into account the intrinsic motility diversity of living matter. A mixture of "fast" and "slow" self-propelled Brownian particles is considered in the presence of a wall. The evolution of the wetting layer thickness shows an overshoot before stationarity and its composition evolves in two stages, equilibrating after a slow elimination of excess particles. Nonmonotonic evolutions are shown to arise from delayed avalanches towards the dilute phase combined with the emergence of a transient particle front.
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Affiliation(s)
| | - Pablo de Castro
- ICTP South American Institute for Fundamental Research & Instituto de Física Teórica, Universidade Estadual Paulista - UNESP, 01140-070 São Paulo, Brazil
| | - Rodrigo Soto
- Departamento de Física, FCFM, Universidad de Chile, Avenida Blanco Encalada 2008, Santiago, Chile
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Forget M, Adiba S, Brunnet LG, De Monte S. Heterogeneous individual motility biases group composition in a model of aggregating cells. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1052309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Aggregative life cycles are characterized by alternating phases of unicellular growth and multicellular development. Their multiple, independent evolutionary emergence suggests that they may have coopted pervasive properties of single-celled ancestors. Primitive multicellular aggregates, where coordination mechanisms were less efficient than in extant aggregative microbes, must have faced high levels of conflict between different co-aggregating populations. Such conflicts within a multicellular body manifest in the differential reproductive output of cells of different types. Here, we study how heterogeneity in cell motility affects the aggregation process and creates a mismatch between the composition of the population and that of self-organized groups of active adhesive particles. We model cells as self-propelled particles and describe aggregation in a plane starting from a dispersed configuration. Inspired by the life cycle of aggregative model organisms such as Dictyostelium discoideum or Myxococcus xanthus, whose cells interact for a fixed duration before the onset of chimeric multicellular development, we study finite-time configurations for identical particles and in binary mixes. We show that co-aggregation results in three different types of frequency-dependent biases, one of which is associated to evolutionarily stable coexistence of particles with different motility. We propose a heuristic explanation of such observations, based on the competition between delayed aggregation of slower particles and detachment of faster particles. Unexpectedly, despite the complexity and non-linearity of the system, biases can be largely predicted from the behavior of the two corresponding homogenous populations. This model points to differential motility as a possibly important factor in driving the evolutionary emergence of facultatively multicellular life-cycles.
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Ress V, Traulsen A, Pichugin Y. Eco-evolutionary dynamics of clonal multicellular life cycles. eLife 2022; 11:78822. [PMID: 36099169 PMCID: PMC9470158 DOI: 10.7554/elife.78822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 08/09/2022] [Indexed: 11/27/2022] Open
Abstract
The evolution of multicellular life cycles is a central process in the course of the emergence of multicellularity. The simplest multicellular life cycle is comprised of the growth of the propagule into a colony and its fragmentation to give rise to new propagules. The majority of theoretical models assume selection among life cycles to be driven by internal properties of multicellular groups, resulting in growth competition. At the same time, the influence of interactions between groups on the evolution of life cycles is rarely even considered. Here, we present a model of colonial life cycle evolution taking into account group interactions. Our work shows that the outcome of evolution could be coexistence between multiple life cycles or that the outcome may depend on the initial state of the population – scenarios impossible without group interactions. At the same time, we found that some results of these simpler models remain relevant: evolutionary stable strategies in our model are restricted to binary fragmentation – the same class of life cycles that contains all evolutionarily optimal life cycles in the model without interactions. Our results demonstrate that while models neglecting interactions can capture short-term dynamics, they fall short in predicting the population-scale picture of evolution.
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Affiliation(s)
- Vanessa Ress
- Max Planck Institute for Evolutionary Biology
- Hamburg Center for Health Economics, University of Hamburg
| | | | - Yuriy Pichugin
- Max Planck Institute for Evolutionary Biology
- Department of Ecology and Evolutionary Biology, Princeton University
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Adiba S, Forget M, De Monte S. Evolving social behaviour through selection of single-cell adhesion in Dictyostelium discoideum. iScience 2022; 25:105006. [PMID: 36105585 PMCID: PMC9464967 DOI: 10.1016/j.isci.2022.105006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 06/09/2022] [Accepted: 08/19/2022] [Indexed: 11/30/2022] Open
Abstract
The social amoeba Dictyostelium discoideum commonly forms chimeric fruiting bodies. Genetic variants that produce a higher proportion of spores are predicted to undercut multicellular organization unless cooperators assort positively. Cell adhesion is considered a primary factor driving such assortment, but evolution of adhesion has not been experimentally connected to changes in social performance. We modified by experimental evolution the efficiency of individual cells in attaching to a surface. Surprisingly, evolution appears to have produced social cooperators irrespective of whether stronger or weaker adhesion was selected. Quantification of reproductive success, cell-cell adhesion, and developmental patterns, however, revealed two distinct social behaviors, as captured when the classical metric for social success is generalized by considering clonal spore production. Our work shows that cell mechanical interactions can constrain the evolution of development and sociality in chimeras and that elucidation of proximate mechanisms is necessary to understand the ultimate emergence of multicellular organization. Cooperative behavior evolved as a pleiotropic effect of selection for surface adhesion Multicellular development of evolved lines with the ancestor follows two different paths A metric of social behavior including clonal development differentiates these two paths
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Affiliation(s)
- Sandrine Adiba
- Institut de Biologie de l’ENS (IBENS), Département de biologie, Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
- Corresponding author
| | - Mathieu Forget
- Institut de Biologie de l’ENS (IBENS), Département de biologie, Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
- Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Silvia De Monte
- Institut de Biologie de l’ENS (IBENS), Département de biologie, Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
- Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plön, Germany
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