Biology subjects

Rolland, J.

Publications and source records attributed to Rolland, J..

8 recordsLinked to original sources

bioRxiv2026

Distance-to-optimum biological drift as a new framework for interpreting routine laboratory results: a benchmark against Reference Change Values across 62 routine biomarkers

BackgroundWe propose the biological drift framework for the interpretation of biological test results: a z-score-like frame-work based on optimized and personalized reference populations and a distance-to-optimum drift metric for longitudinal interpretation relative to an estimated individual optimum. We benchmarked biological drifts against Reference Change Values (RCVs), which are used to interpret serial laboratory results by defining the minimum change expected to exceed normal within-subject biological variation (CVi). ObjectivesTo benchmark biological drifts against the classical biological-variation framework and assess their consistency with RCV thresholds across routine biomarkers. MethodsFor 62 routine biomarkers, biological drift levels were compared with RCVs after transformation to test the consistency between the two frameworks. ResultsSevere biological drifts mostly exceeded the 95% RCV threshold, indicating changes unlikely to be explained by short-term biological variation alone. In contrast, moderate drifts reached the 95% RCV threshold for approximately one in two biomarkers, suggesting that many moderate distance-to-optimum deviations may remain within expected variability, particularly for biomarkers with large within-subject variation (CVi). Results are particularly interesting for the follow-up of people with diabetes and for the management of thyroid and hepatic disorders. ConclusionsBiological drifts derived from optimized personalized reference populations are broadly consistent with the RCV framework for identifying biologically meaningful deviations from the optimum and may therefore be relevant for the monitoring of certain biomarkers across several medical conditions in clinical practice.

biochemistry↗

bioRxiv2025

Comparative efficacy of multi micro-stimulation alveolar (MMSA) and traditional vacuum therapy on skin biomechanics integrity, and inflammation

This study compares the effects of Multi Micro-Stimulation Alveolar (MMSA) therapy and traditional vacuum therapy on human skin explants, focusing on skin elasticity, collagen organization, and inflammatory responses. Advanced imaging modalities, including Second Harmonic Generation (SHG) microscopy and Selective Plane Illumination Microscopy (SPIM), were used for in-depth analysis. MMSA therapy was found to significantly improve skin elasticity, maintain collagen structure, limit reactive oxygen species (ROS) production, and promote tissue regeneration. In contrast, traditional vacuum therapy was associated with increased collagen breakdown, higher ROS production, and diminished structural integrity of the skin. These results identify MMSA as a more effective and safer approach for non-invasive skin treatment in both cosmetic and medical contexts.

biophysics↗

bioRxiv2020

Effect of structural stability on endolysosomal degradation and T-cell reactivity of major shrimp allergen tropomyosin

BackgroundTropomyosins are highly conserved proteins, an attribute that forms the molecular basis for their IgE antibody cross-reactivity. Despite structural similarities, their allergenicity varies greatly between ingested and inhaled invertebrate sources. In this study, we investigated the relationship between the structural stability of different tropomyosins, their endolysosomal degradation patterns and T-cell reactivity. MethodsWe investigated the differences between four tropomyosins - the major shrimp allergen Pen m 1 and the minor allergens Der p 10 (dust mite), Bla g 7 (cockroach) and Ani s 3 (fish parasite) - in terms of IgE binding, structural stability, endolysosomal degradation and subsequent peptide generation, and T-cell cross-reactivity in a BALB/c murine model. ResultsDespite their conserved primary structure and consequent IgE co-reactivity, the invertebrate tropomyosins displayed different protein stabilities. Pen m 1 and Ani s 3, but not Der p 10 and Bla g 7 elicited differential melting temperatures that were pH-dependent. Endolysosomal experiments demonstrated differential degradation, as a function of stability, generating different peptide repertoires. Pen m 1 T-cell clones, with specificity for sequences highly conserved in all four tropomyosins, did not proliferate with Der p 10, Bla g 7 and Ani s 3, indicating that these peptides were not naturally produced for other invertebrate tropomyosins. ConclusionsOur data suggest that, although invertebrate tropomyosins exhibit a high degree of IgE cross-reactivity due to conserved B-cell epitopes, they do not necessarily share identical cross-reactive T-cell epitopes. This is likely due to differential endolysosomal processing as a function of different structural stabilities.

immunology↗

bioRxiv2019

Vulnerability correlates with life history traits and the load of deleterious mutations in fish.

Understanding why some species accumulate more deleterious substitutions than others is an important question relevant in evolutionary biology and conservation sciences. Previous studies conducted in terrestrial taxa suggest that life history traits correlate with the efficiency of purifying selection and accumulation of deleterious mutations. Using a large genome dataset of 76 species of fishes, we show that the rate of deleterious mutation accumulation (measured via dN/dS, i.e. non-synonymous over synonymous substitution rate) is associated to the vulnerability, the life-history strategies, and the latitude of species. Our results, focusing on a large clade of aquatic species, generalizes previous patterns found so far in few clades of terrestrial vertebrates. These results also suggest that vulnerable species accumulate more deleterious substitutions than non-threatened ones, which give insights in how life-history traits, populations sizes and genetic risk of extinction can be tightly interconnected.

molecular biology↗

bioRxiv2019

Climatic niche change of fish is faster at high latitude and in marine environments

Change in species climatic niches is a key mechanism influencing species distribution patterns. The question of which factors impact niche change remains a highly debated topic in evolutionary biology. Previous studies have proposed that rates of climatic niche change might be correlated with climatic oscillations at high latitude or adaptation to new environmental conditions. Yet, very few studies have asked if those factors are also predominant in aquatic environments. Here, we reconstruct the climatic niche changes of fish species on a new phylogeny encompassing 12,616 species. We first confirm that the rate of niche change is faster at high latitude and show that this association is steeper for freshwater than for marine species. We also show that freshwater species have slower rates of niche change than marine species. These results may be explained by the fact that freshwater species have larger climatic niche breadth and thermal safety margin than marine species at high latitude. Overall, our study sheds a new light on the environmental conditions and species features impacting rates of climatic niche change in aquatic habitats.

evolutionary biology↗

bioRxiv2019

On the effect of asymmetrical trait inheritance on models of trait evolution

Current phylogenetic comparative methods modeling quantitative trait evolution generally assume that, during speciation, phenotypes are inherited identically between the two daughter species. This, however, neglects the fact that species consist of a set of individuals, each bearing its own trait value. Indeed, because descendent populations after speciation are samples of a parent population, we can expect their mean phenotypes to randomly differ from one another potentially generating a "jump" of mean phenotypes due to asymmetrical trait inheritance at cladogenesis. Here, we aim to clarify the effect of asymmetrical trait inheritance at speciation on macroevolutionary analyses, focusing on model testing and parameter estimation using some of the most common models of quantitative trait evolution. We developed an individual-based simulation framework in which the evolution of species phenotypes is determined by trait changes at the individual level accumulating across generations and cladogenesis occurs then by separation of subsets of the individuals into new lineages. Through simulations, we assess the magnitude of phenotypic jumps at cladogenesis under different modes of trait inheritance at speciation. We show that even small jumps can strongly alter both the results of model selection and parameter estimations, potentially affecting the biological interpretation of the estimated mode of evolution of a trait. Our results call for caution when interpreting analyses of trait evolution, while highlighting the importance of testing a wide range of alternative models. In the light of our findings, we propose that future methodological advances in comparative methods should more explicitly model the intra-specific variability around species mean phenotypes and how it is inherited at speciation.

evolutionary biology↗

bioRxiv2017

Testing the role of the Red Queen and Court Jester as drivers of the macroevolution of Apollo butterflies

In macroevolution, the Red Queen (RQ) model posits that biodiversity dynamics depend mainly on species-intrinsic biotic factors such as interactions among species or life-history traits, while the Court Jester (CJ) model states that extrinsic environmental abiotic factors have a stronger role. Until recently, a lack of relevant methodological approaches has prevented the unraveling of contributions from these two types of factors to the evolutionary history of a lineage. Here we take advantage of the rapid development of new macroevolution models that tie diversification rates to changes in paleoenvironmental (extrinsic) and/or biotic (intrinsic) factors. We inferred a robust and fully-sampled species-level phylogeny, as well as divergence times and ancestral geographic ranges, and related these to the radiation of Apollo butterflies (Parnassiinae) using both extant (molecular) and extinct (fossil/morphological) evidence. We tested whether their diversification dynamics are better explained by a RQ or CJ hypothesis, by assessing whether speciation and extinction were mediated by diversity-dependence (niche filling) and clade-dependent host-plant association (RQ) or by large-scale continuous changes in extrinsic factors such as climate or geology (CJ). For the RQ hypothesis, we found significant differences in speciation rates associated with different host-plants but detected no sign of diversity-dependence. For CJ, the role of Himalayan-Tibetan building was substantial for biogeography but not a driver of high speciation, while positive dependence between warm climate and speciation/extinction was supported by continuously varying maximum-likelihood models. We find that rather than a single factor, the joint effect of multiple factors (biogeography, species traits, environmental drivers, and mass extinction) is responsible for current diversity patterns, and that the same factor might act differently across clades, emphasizing the notion of opportunity. This study confirms the importance of the confluence of several factors rather than single explanations in modeling diversification within lineages.

evolutionary biology↗

bioRxiv2017

Evolutionary history of New World monkeys revealed by molecular and fossil data

New World monkeys (parvorder Platyrrhini) are one of the most diverse groups of primates, occupying today a wide range of ecosystems in the American tropics and exhibiting large variations in ecology, morphology, and behavior. Although the relationships among the almost 200 living species are relatively well understood, we lack robust estimates of the timing of origin, the ancestral morphology, and the evolution of the distribution of the clade. Here we integrate paleontological and molecular evidence to investigate the evolutionary dynamics of extinct and extant platyrrhines. We develop an analytical framework to infer ancestral states, the evolution of body mass, and changes in latitudinal ranges through time. Our results show that extant platyrrhines originated some 5-10 million years earlier than previously assumed, likely dating back to the Middle Eocene ([~] 43 million years ago, Ma). The estimated ancestral platyrrhine was strikingly small - weighing [~] 0.4 kg, as compared to the largest modern species over 10 kg - matching the size of their presumed Eocene North African ancestors. Small-sized callitrichines (marmosets and tamarins) retained a small body mass throughout their evolutionary history, thus challenging the hypothesis of phyletic dwarfism as an explanation to their adaptive traits. In contrast, a rapid change in body mass range took place as the three families diverged between the Late Oligocene and the Early Miocene. That period also marks a peak in diversity of fossil platyrrhines and is associated with their widest latitudinal range, expanding as far to the South as Patagonia. This geographic expansion is temporally coincident with a significant increase in platyrrhine population size inferred from genomic data, and with warm and humid climatic conditions linked to the Miocene Climatic Optimum and the lower elevation of the Andes. These results unveil the early evolution of an iconic group of monkeys and showcase the advantages of integrating fossil and molecular data for estimating evolutionary rates and trends.

evolutionary biology↗