Biology subjects

Arias Del Angel, J. A.

Publications and source records attributed to Arias Del Angel, J. A..

5 recordsLinked to original sources

bioRxiv2021

The environment topography alters the transition from single-cell populations to multicellular structures in Myxococcus xanthus

The social soil-dwelling bacteria Myxococcus xanthus can form multicellular structures, known as fruiting bodies. Experiments in homogeneous environments have shown that this process is affected by the physico-chemical properties of the substrate, but they have largely neglected the role of complex topographies. We experimentally demonstrate that the topography alters single-cell motility and multicellular organization in M. xanthus. In topographies realized by randomly placing silica particles over agar plates, we observe that the cells interaction with particles drastically modifies the dynamics of cellular aggregation, leading to changes in the number, size and shape of the fruiting bodies, and even to arresting their formation in certain conditions. We further explore this type of cell-particle interaction in a minimal computational model. These results provide fundamental insights into how the environment topography influences the emergence of complex multicellular structures from single cells, which is a fundamental problem of biological, ecological and medical relevance.

biophysics↗

bioRxiv2020

Interplay of mesoscale physics and agent-like behaviors in the parallel evolution of aggregative multicellularity

Myxobacteria and dictyostelids are prokaryotic and eukaryotic multicellular lineages, respectively, that after nutrient depletion aggregate and develop into structures called fruiting bodies. The developmental processes and the resulting morphological outcomes resemble one another to a remarkable extent despite their independent origins, the evolutionary distance between them and the lack of traceable levels of homology in the molecular mechanisms of the groups. We hypothesize that the morphological parallelism between the two lineages arises as the consequence of the interplay, within multicellular aggregates, between generic processes, physical and physicochemical processes operating similarly in living and non-living matter at the mesoscale (~10-3-10-1 m) and agent-like behaviors, unique to living systems, characteristic of the constituent cells. To this effect, we analyze the relative contribution of the generic and agent-like determinants in the main phenomena of myxobacteria and dictyostelid development, and their roles in the emergence of their shared traits. We show that as a consequence of aggregation collective cell-cell contacts mediate the emergence of liquid-like properties, making nascent multicellular masses subject to new sets of patterning and morphogenetic processes. In both lineages, this leads to behaviors such as streaming, rippling, and rounding up, similar to effects observed in non-living fluids. Later the aggregates solidify, leading them to exhibit additional generic properties and motifs. We consider evidence that the morphological phenotypes of the multicellular masses deviate from the predictions of generic physics due to the contribution of agent-like behaviors. These include directed migration, quiescence, and oscillatory signal transduction of the cells mediated by responses to external cues acting through species-specific regulatory and signaling mechanisms reflecting the evolutionary histories of the respective organisms. We suggest that the similar developmental trajectories of Myxobacteria and Dictyostelia are more plausibly due to shared generic physical processes in coordination with analogous agent-type behaviors than to convergent evolution under parallel selection regimes. Finally, we discuss the broader implications of the existence and synergy of these two categories of developmental factors for evolutionary theory.

developmental biology↗

bioRxiv2019

A Systems Biology perspective of Dynamical Patterning Modules in the transition to multicellularity: lessons from an aggregative bacteria

Development and evolution are dynamical processes under the continuous control of organismic and environmental factors. Generic physical processes, associated with biological materials and certain genes or molecules, provide a morphological template for the evolution and development of organism forms. Generic dynamical behaviors, associated with recurring network motifs, provide a temporal template for the regulation and coordination of biological processes. The role of generic physical processes and their associated molecules in development is the topic of the Dynamical Patterning Module (DPM) framework. The role of generic dynamical behaviors in biological regulation is studied via the identification of the associated Network Motifs (NM). We propose a joint DPM-NM perspective on the emergence and regulation of multicellularity focusing on a multicellular aggregative bacterium, Myxococcus xanthus. Understanding M. xanthus development as a dynamical process embedded in a physical substrate provides novel insights into the interaction between developmental regulatory networks and generic physical processes in the evolutionary transition to multicellularity.

systems biology↗

bioRxiv2019

Role of aggregate size, multistability and communication in determining cell fate and patterning in M. xanthus

1.The emergence of multicellular organisms that exhibit cell differentiation and stereotypic spatial arrangements has been recognized as one of the major transitions in evolution. Myxobacteria have emerged as a useful study model to investigate multicellular evolution and development. Here, we propose a multiscale model that considers cellular adhesion and movement, molecular regulatory networks (MRNs), and cell-to-cell communication to study the emergence of cell fate determination and spatial patterning of Myxococcus xanthus fruiting bodies. The model provides a dynamic accounting of the roles of MRN multistability, intercellular communication and conglomerate size in determining cell fate and patterning during M. xanthus development. It also suggests that for cell fate determination and patterning to occur, the cell aggregate must surpass a minimum size. The model also allows us to contrast alternative scenarios for the C-signal mechanism and provides stronger support for an indirect effect (as a diffusible molecule) than a direct one (as a membrane protein).

developmental biology↗

bioRxiv2018

Plastic multicellular development of Myxococcus xanthus: genotype-environment interactions in a physical gradient

In order to investigate the contribution of the physical environment to variation in multicellular development of Myxococcus xanthus, phenotypes developed by different genotypes in a gradient of substrate stiffness conditions were quantitatively characterized. Statistical analysis showed that plastic phenotypes result from the genotype, the substrate conditions and the interaction between them. Also, phenotypes were expressed with scale- and trait-specificity. Overall, the presented information highlights the constructive role of the physical context in the development of microbial multicellularity, with both ecological and evolutionary implications.

developmental biology↗