Stephen J Knabel, Ramaswamy Anantheswaran, Aubrey Mendonca, Wei Zhang
{"title":"Toxin-antitoxins and sigma factors may optimize the fitness of free-living bacteria throughout the life cycle via an integrated nutrient-responsive cybernetic system.","authors":"Stephen J Knabel, Ramaswamy Anantheswaran, Aubrey Mendonca, Wei Zhang","doi":"10.1098/rsif.2025.0185","DOIUrl":"10.1098/rsif.2025.0185","url":null,"abstract":"<p><p>Toxin-antitoxin systems (TASs) are ubiquitous in the chromosomes of free-living bacteria, yet their primary biological function remains poorly understood. Bacteria reproduce exponentially via 2<sup><i>n</i></sup> growth kinetics and thus must respond to changing nutrient availability to reproduce rapidly during short periods of feast and survive during long periods of famine. Type II TASs represent stable enzyme-unstable inhibitor systems that are regulated by reversible competitive inhibition, which allows them to efficiently produce pleiotropic effects on prokaryotic cells in a continuous (analogue) manner due to varying concentrations of free toxin throughout the life cycle. A nutrient-responsive cybernetic system (NRCS) model is proposed where intracellular nutrient concentration feeds back to control the emergent properties of growth, death and growth/death arrest, which results in a novel fitness strategy termed K Sensing and Control. When nutrients become limiting, alternative general stress response sigma factors Ϭ<sup>S</sup> and Ϭ<sup>B</sup> regulate the expression of hundreds of genes that may control the transformation of vegetative bacteria into coccoid, stress-tolerant 'motherspores'. An integrated NRCS model is presented that shows how TASs and sigma factors may work in concert to efficiently regulate population dynamics, cellular physiology and cellular differentiation throughout the life cycle, which optimizes the biological fitness of free-living bacteria.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250185"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12440627/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145075570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abdul-Hakeem Omotayo, Fushing Hsieh, Yiduo Wei, Paula Guzmán-Delgado, Giulia Marino, Barbara Blanco-Ulate
{"title":"Evolving topological colour landscape unravels the final stages of pistachio nut development and the incidence of blank nuts.","authors":"Abdul-Hakeem Omotayo, Fushing Hsieh, Yiduo Wei, Paula Guzmán-Delgado, Giulia Marino, Barbara Blanco-Ulate","doi":"10.1098/rsif.2025.0119","DOIUrl":"10.1098/rsif.2025.0119","url":null,"abstract":"<p><p>Pistachio is a major nut crop worldwide; however, there is a lack of standardized non-destructive methods to effectively evaluate maturity and kernel filling for improved management and harvest timing. This study presents an image-based approach to determine pistachio nut maturation and blank kernel incidence by analysing the surface colour patterns of individual nuts at three time points during late development. We identified eight major hull colours to represent the full colour spectrum and applied principal component analysis to divide each nut into seven spatial sections. Within each section, we constructed eight colour-based feature variables (covariates) and associated them with a binary response variable indicating kernel presence or absence. We explored the specific response-covariate relationships at each developmental time point using a data-driven method called categorical exploratory data analysis, which identified key first-order and second-order feature-categories that link hull colour patterns with kernel status. These relationships were visualized using block-structured heatmaps, revealing consistent distinctions between filled and blank nuts. Based on these findings, we developed an algorithm with two main functions: (i) identifying a nut's growth stage from its image for optimal harvest timing and (ii) estimating blank nut incidence for quality assessment and economic decision-making.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250119"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12457914/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145131088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tianran Wan, Edward D Johnstone, Shier Nee Saw, Oliver E Jensen, Igor L Chernyavsky
{"title":"A functional shunt in the umbilical cord: the role of coiling in solute and heat transfer.","authors":"Tianran Wan, Edward D Johnstone, Shier Nee Saw, Oliver E Jensen, Igor L Chernyavsky","doi":"10.1098/rsif.2025.0148","DOIUrl":"10.1098/rsif.2025.0148","url":null,"abstract":"<p><p>The umbilical cord plays a critical role in delivering nutrients and oxygen from the placenta to the fetus through the umbilical vein, while the two umbilical arteries carry deoxygenated blood with waste products back to the placenta. Although solute exchange in the placenta has been extensively studied, exchange within the cord tissue has not been investigated. Here, we explore the hypothesis that the coiled structure of the umbilical cord could strengthen diffusive coupling between the arteries and the vein, resulting in a functional shunt. We calculate the diffusion of solutes, such as oxygen, and heat in the umbilical cord to quantify how this shunt is affected by vascular configuration within the cord. We demonstrate that the shunt is enhanced by coiling and vessel proximity. Furthermore, our model predicts that typical vascular configurations of the human cord tend to minimize shunting, which could otherwise disrupt thermal regulation of the fetus. We also show that the exchange, amplified by coiling, can provide additional oxygen supply to the cord tissue surrounding the umbilical vessels.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250148"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12457040/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145131149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nanoparticle deposition to a cell transiting through a soft tissue: three-dimensional simulation and Lagrangian coherent structure dynamics.","authors":"Mazyar Dawoodian, Amalendu Sau","doi":"10.1098/rsif.2025.0270","DOIUrl":"10.1098/rsif.2025.0270","url":null,"abstract":"<p><p>We elucidate the role of time-invariant spatial attractors-repellers in segregating nano-suspensions around a tumour cell. A major challenge for targeted therapeutic drug delivery is the inadequate understanding of active nano-bio-separatrices at the delivery site. Using the lattice-Boltzmann-immersed-boundary method, first, we simulate the kinematics of a compound cell in a micro-vessel partly blocked by an invasive tissue and examine the stretching of its plasma membrane (PM) and nuclear envelope (NE) for varied nucleus size, capillary number and blockage hole. Second, we compute the trajectories of the suspended large number of inertial nanoparticles (NPs) in the vessel using a dynamical system approach. Third, we compute the particle Lagrangian coherent structures (pLCS) for the advecting NPs and identify the time-invariant geometric separatrices. The dominant attractive-repulsive pLCS effectually demarcates fluid regions from where NPs move closer/attach to the cell and from where NPs move away. Our study explains that delivering nanomedicine to a cell is feasible only through its stretched PM's high-tension rear side. The created repulsive pLCS barricades NPs from moving closer to a cell's PM's low-tension lateral/front sides. We thus unfold a universal separation behaviour of NPs around a cell. NP delivery rate increased for a larger capillary number and cell nucleus size. It decreased for heavier NPs and a cell stiffer nucleus/NE.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250270"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12440631/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145075652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lény Lego, Clément Cornec, Siloé Corvin, Mathilde Massenet, Leo Papet, Hugues Patural, David Reby, François Jouen, Nicolas Mathevon
{"title":"Nonlinear acoustic phenomena tune the adults' facial thermal response to baby cries with the cry amplitude envelope.","authors":"Lény Lego, Clément Cornec, Siloé Corvin, Mathilde Massenet, Leo Papet, Hugues Patural, David Reby, François Jouen, Nicolas Mathevon","doi":"10.1098/rsif.2025.0150","DOIUrl":"10.1098/rsif.2025.0150","url":null,"abstract":"<p><p>Getting caregivers to respond to their pain cries is vital for the human baby. Previous studies have shown that certain features of baby cries-the nonlinear phenomena (NLP)-enable caregivers to assess the pain felt by the baby. However, the extent to which these NLP mobilize the autonomic nervous system of an adult listener remains unexplored. Here, we show that variations in a listener's facial temperature, a marker of the autonomic emotional response, reflect the pain expressed by a baby's cry. Specifically, by conducting listening experiments with cries expressing mild discomfort or acute pain, we demonstrate that NLP modulate the facial thermal response in adult listeners, irrespective of sex and of cry pitch variation. The temporal dynamics of the thermal response is more closely synchronized with the amplitude envelope of the acoustic signal when listening to a cry containing a large level of NLP than when NLP are less prominent. The pain encoded in a baby's cry thus generates a synchronized emotional response in both adult men and women, emphasizing that our ability to decode the information carried by babies' cries integrates an immediate activation of the autonomic nervous system before engaging higher-order cognitive processes.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250150"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12419898/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145030003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jessica L Dobson, Frane Babarovic, Michaël Pj Nicolaï, Gerben Debruyn, Matthew D Shawkey, Liliana D'Alba
{"title":"Multilayer thin-film produces recurrent evolution of iridescence in mammals.","authors":"Jessica L Dobson, Frane Babarovic, Michaël Pj Nicolaï, Gerben Debruyn, Matthew D Shawkey, Liliana D'Alba","doi":"10.1098/rsif.2025.0508","DOIUrl":"10.1098/rsif.2025.0508","url":null,"abstract":"<p><p>Iridescent coloration is a vibrant structural colour that is widespread in nature, but in mammals is thought to be limited. Although multiple rodent and Eulipotyphlan species have been anecdotally described as iridescent, empirical evidence outside of the Chrysochloridae (golden mole) family is lacking. As iridescence in golden moles is created through a thin-film mechanism from a compressed cuticle structure, and the structure of hair is highly conserved, we expect iridescence to be present, and produced by the same mechanism, in mammals that share similar hair properties. Here, we test this hypothesis by first collecting and analysing existing documentation of iridescence in mammals, finding written evidence spanning 25 genera across eight mammalian families. We then identified the underlying mechanisms of iridescence for 14 species from Rodentia and Afrosoricida (including one outside Chrysochloridae), and showed that iridescence in these species is created through the same system of thin, alternating layers of keratin and probably lipid-rich material within the cuticle, in similar proportions as Chrysochloridae. These data suggest that iridescence in mammals is more common than originally thought, adding another dimension to mammal coloration research.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250508"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12419891/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145030092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cailin B Casey, Braden Cote, Chelsea Heveran, Mark Jankauski
{"title":"Wing hinge dynamics influence stroke amplitudes in flapping wing insects: a frequency response approach.","authors":"Cailin B Casey, Braden Cote, Chelsea Heveran, Mark Jankauski","doi":"10.1098/rsif.2025.0074","DOIUrl":"10.1098/rsif.2025.0074","url":null,"abstract":"<p><p>Flapping wing insects leverage the dynamics of their compliant flight systems to reduce the energetic costs of flying. However, the extent to which the wing hinge dynamics contribute to the overall system dynamics remains unknown. Therefore, we developed an approach to (i) quantify the passive dynamic properties of the wing hinge and (ii) identify the resonant frequency of the isolated wing/wing hinge system. First, we measured the frequency response relating thorax deformation to wing stroke angle in sacrificed honeybees and army cutworm moths. Using these data, we developed a linear model of the flight system, which we then extended to incorporate nonlinear effects associated with large wing stroke angles. Our findings revealed that both species flap below the linear resonance of the wing hinge. At larger angles, nonlinear aerodynamic damping reduces the resonant frequency, causing both species to flap above wing hinge resonance. We discuss how wing-thorax coupling and muscle dynamics may cause the resonant frequency of the entire flight system to deviate from that of the wing/wing hinge system. Our estimates of wing hinge stiffness and damping provide quantitative parameters that can be incorporated into models of the insect flight system to enable more accurate predictions of resonance behaviour.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250074"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12440615/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145075581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Precession dynamics and morphology of rolling samaras.","authors":"Breanna Marie Schaeffer, Andrew Keith Dickerson","doi":"10.1098/rsif.2025.0391","DOIUrl":"10.1098/rsif.2025.0391","url":null,"abstract":"<p><p>Samaras of species such as <i>Fraxinus americana</i>, <i>Fraxinus excelsior</i> and <i>Liriodendron tulipifera</i> exhibit a unique dual-axis descent characterized by spanwise rolling superimposed on vertical helical precession. While prior work has established the aerodynamic mechanisms of non-rolling samaras, <i>Acer</i> spp. serving as the classic example,, the aerodynamic role of rolling motion remains largely uncharacterized. Here, we present a comparative kinematic and morphological analysis of 30 rolling samaras across three species using high-speed multi-camera imaging and digital tracking. Our results reveal that all species maintain stable autorotation by rolling approximately seven cycles for each precession cycle, inducing periodic modulation of angle of attack and sinusoidal lift generation without observable wingtip wobble. Species-specific variation in wingspan, mass and thickness generates distinct descent velocities, but across all groups wing thickness emerges as the single most predictive morphological trait. We demonstrate that descent velocity scales inversely with thickness, with additional inverse power-law relationships linking thickness to both rolling and precessional angular velocities. Analytical modelling of lift-induced torque predicts negligible vertical oscillation, confirming observations. Samaras released into a vertical wind tunnel from a static position show that the time to stable autorotation strongly depends on the initial release orientation. In our observations, rolling begins before precession, and the stochastic direction of rolling sets the precessional direction.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250391"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12457913/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145131163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ageing-related decline of translation as a consequence of transcription dysregulation.","authors":"Sebastian Pechmann","doi":"10.1098/rsif.2025.0323","DOIUrl":"10.1098/rsif.2025.0323","url":null,"abstract":"<p><p>The ageing-related decline of translational fidelity disrupts cellular protein homeostasis, thus contributing to the onset of cancer and neurodegeneration. However, it remains unclear what alters speed and accuracy of translation at advanced age. Here, I show that the shift in translation kinetics upon ageing is systematic and a direct consequence of transcription deregulation. Computational modelling of ageing yeast and worm Riboseq data demonstrates that the loss of translational fidelity is independent of codon identity, tRNA abundances or the specificities of anticodon-codon interactions at the ribosome. Instead, large-scale transcriptional changes during ageing perturb the codon usage of the transcriptome, which at the systems level induces a dramatic remodelling and increase in ribosome collisions and stalling. Ribosome collisions in turn reduce control over translation elongation and effect an assimilation of codon translation rates. The presented results thus explain the ageing-related decline of translational fidelity, and provide important insights towards a systems-level understanding of ageing-related human diseases linked to mistranslation and protein homeostasis failure that are especially prevalent in the brain.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250323"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12457020/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145131090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Olivia K Walthaus, Dilanka I Deegala, Raphael Delattre, David Labonte
{"title":"Biomechanical components of the plant-insect herbivore arms race: a model test in leaf-cutter ants.","authors":"Olivia K Walthaus, Dilanka I Deegala, Raphael Delattre, David Labonte","doi":"10.1098/rsif.2025.0091","DOIUrl":"10.1098/rsif.2025.0091","url":null,"abstract":"<p><p>Insects and plants have been locked in an evolutionary arms race spanning 350 million years. Insects evolved specialized tools to cut into plant tissue, and plants, to counter these attacks, developed diverse defence strategies. Much previous worked has focused on chemical defences. How can plants vary their mechanical properties to deter herbivores, and how can insects respond? We test a simple mechanical model that relates the force required to cut thin, leaf-like tissues to their mechanical properties and the geometry of the cutting tool. To remove the confounding effects of tool shape across size, we use leaf-cutter ant mandibles as a model system. Cutting forces were measured for pristine and worn mandibles that vary by one order of magnitude in size, using a custom-built fibre-optic set-up and homogeneous pseudoleaves as well as a set of plant tissues as model substrates. The results substantially support the model, enabling quantitative predictions. Fracture toughness is identified as a key mechanical defence trait for plants, cutting edge radius as the critical geometric property of the insect mandible and cutting edge wear consequently emerges as a key modulator of cutting forces, elevating it up to fivefold above a physical minimum. Thus, plants may be served by implementing strategies that maximize wear, whereas insects should seek to minimize it.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 230","pages":"20250091"},"PeriodicalIF":3.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12419890/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145030050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}