Biology subjects

Larios, D.

Publications and source records attributed to Larios, D..

3 recordsLinked to original sources

bioRxiv2025

Reverse Engineering the Evolutionary Logic of Cytoskeletal Dynamics

Eukaryotic cells generate mechanical forces through cytoskeletal filaments actively reorganized by families of molecular motors. However, how motor sequence specifies filament organization dynamics remains unclear. We developed ActiveDROPS, a cell-free platform that expresses kinesin variants in bacterial lysate droplets and quantitatively maps the resulting microtubule dynamics into a common phenotype space. Across a library of twelve kinesin-1 homologs, we observed three phenotypes: "Slow-Sustained" flows that activate after 8 h, reach peak mean velocities of 24 nm/s and decay after [~]32 h; "Fast-Burst" flows that activate within minutes and dissipate within 2 h, reaching velocities up to 900 nm/s; and a [~]36-h "Multiphase" progression through nematic, rotational, and contractile states. Microtubule gliding assays and molecular dynamics simulations using AlphaFold-predicted structures linked the "Fast-Burst" phenotype to generally faster motility and more favorable motor-tubulin interactions than "Slow-Sustained". By replacing the microtubule-binding region of a "Slow-Sustained" motor with that of a "Fast-Burst" motor, we generated a "Fast-Sustained" chimera with flows that activate within 1 h, peak at 70 nm/s and persist for 16 h, showing that recombination can reprogram the parental relationship between speed and timing of microtubule-motor self-organization. These results reveal a constrained logic through which kinesin sequence shapes cytoskeletal dynamics, providing a framework for dissecting the mechanical repertoire available to cellular systems.

synthetic biology↗

bioRxiv2025

Force Propagation in Active Cytoskeletal Networks

Conventional materials science establishes clear structure-function relationships: grain boundaries modulate strength by blocking dislocations, and defect density limits conductivity through electron scattering. Active matter presents a fundamentally different challenge, components continuously consume energy to generate forces, creating a dual identity as both structural elements and force-generating machines. This material-machine duality raises a fundamental question: which structural parameters govern functional behavior in systems where constituents actively generate forces rather than merely responding to external inputs? Here we demonstrate that percolation is the critical mechanism that transforms active cytoskeletal networks from energy-dissipating materials into work-performing machines. Using light-controlled microtubule-kinesin networks, we show that increasing bundle length from 0.9 {micro}m to 5 {micro}m triggers a percolation transition that enables global force organization. Networks below the threshold remain incapable of performing coordinated work, while networks above it develop correlation lengths exceeding 240 {micro}m, generate 25-fold stronger forces, and extract 1000-fold more mechanical work, powering transport of live cells across 800 {micro}m distances. Network simulations reveal that introducing just 5-10% longer bundles creates a connected component containing 90% of microtubules, establishing the precise threshold that drives this material-to-machine transition. Our findings establish percolation as the fundamental mechanism governing whether active matter systems function as passive materials or as coordinated machines--providing design principles for both synthetic and biological systems. increasing bundle length from 0.9 {micro}m to 5 {micro}m increasing bundle length from 0.9 {micro}m to 5 {micro}m

biophysics↗

bioRxiv2020

Access to Scientific Literature by the Conservation Community

Access to the scientific literature is perceived to be a challenge to the biodiversity conservation community, but actual level of literature access relative to needs has never been assessed globally. We examined this question by surveying the constituency of the International Union for Conservation of Nature (IUCN) as a proxy for the conservation community, generating 2,285 responses. Of these respondents, ∼97% need to use the scientific literature in order to support their IUCN-related conservation work, with ∼50% needing to do so at least once per week. The crux of the survey revolved around the question, “How easy is it for you currently to obtain the scientific literature you need to carry out your IUCN-related work?” and revealed that roughly half (49%) of the respondents find it not easy or not at all easy to access scientific literature. We fitted a binary logistic regression model to explore factors predicting ease of literature access. Whether the respondent had institutional literature access (55% do) is the strongest predictor, with region (Western Europe, the United States, Canada, Australia and New Zealand) and gender (male) also significant predictors. Approximately 60% of respondents from Western Europe, the United States, Canada, Australia and New Zealand have institutional access compared to ∼50% in Asia and Latin America, and ∼40% in Eastern Europe and in Africa. Nevertheless, accessing free online material is a popular means of accessing literature for both those with and without institutional access. The four journals most frequently mentioned when asked which journal access would deliver the greatest improvements to the respondent’s IUCN-related work were Conservation Biology, Biological Conservation, Nature, and Science. The majority prefer to read journal articles on screen but prefer to read books in hard copy. Overall, it is apparent that access to the literature is a challenge facing roughly half of the conservation community worldwide.View Full Text

scientific communication and education↗