Paper List
-
An AI Implementation Science Study to Improve Trustworthy Data in a Large Healthcare System
This paper addresses the critical gap between theoretical AI research and real-world clinical implementation by providing a practical framework for as...
-
The BEAT-CF Causal Model: A model for guiding the design of trials and observational analyses of cystic fibrosis exacerbations
This paper addresses the critical gap in cystic fibrosis exacerbation management by providing a formal causal framework that integrates expert knowled...
-
Hierarchical Molecular Language Models (HMLMs)
This paper addresses the core challenge of accurately modeling context-dependent signaling, pathway cross-talk, and temporal dynamics across multiple ...
-
Stability analysis of action potential generation using Markov models of voltage‑gated sodium channel isoforms
This work addresses the challenge of systematically characterizing how the high-dimensional parameter space of Markov models for different sodium chan...
-
Approximate Bayesian Inference on Mechanisms of Network Growth and Evolution
This paper addresses the core challenge of inferring the relative contributions of multiple, simultaneous generative mechanisms in network formation w...
-
EnzyCLIP: A Cross-Attention Dual Encoder Framework with Contrastive Learning for Predicting Enzyme Kinetic Constants
This paper addresses the core challenge of jointly predicting enzyme kinetic parameters (Kcat and Km) by modeling dynamic enzyme-substrate interaction...
-
Tissue stress measurements with Bayesian Inversion Stress Microscopy
This paper addresses the core challenge of measuring absolute, tissue-scale mechanical stress without making assumptions about tissue rheology, which ...
-
DeepFRI Demystified: Interpretability vs. Accuracy in AI Protein Function Prediction
This study addresses the critical gap between high predictive accuracy and biological interpretability in DeepFRI, revealing that the model often prio...
Countershading coloration in blue shark skin emerges from hierarchically organized and spatially tuned photonic architectures inside skin denticles
City University of Hong Kong | Max Planck Institute of Colloids and Interfaces | University of Salzburg | B CUBE – Center for Molecular Bioengineering | Elasmobranch Research Belgium (ERB) | Medical University Innsbruck | AZTI, Basque Research and Technology Alliance (BRTA) | Hong Kong Polytechnic University
30秒速读
IN SHORT: This paper solves the core problem of how blue sharks achieve their striking dorsoventral countershading camouflage, revealing that coloration originates not from dermal pigments but from hierarchical photonic architectures within individual skin denticles.
核心创新
- Biology Identifies denticles as the primary optical units ('pixels') for shark skin coloration, overturning the assumption that coloration originates from underlying dermal chromatophores.
- Methodology Establishes a multi-scale correlative imaging pipeline (optical, μCT, histology, FIB-SEM, TEM) to link nanoscale crystal organization with macroscopic color gradients.
- Biology Demonstrates a spatial gradient in photonic architecture: from ordered purine-crystal stacks (blue) to disordered assemblies (white), coupled with systematic changes in chromatophore composition and pulp cavity volume (25% in blue zone vs. 17% in white zone).
主要结论
- Blue shark countershading originates from denticle-embedded photonic architectures, not dermal pigments, with pulp cavity volume decreasing from 25% (blue) to 17% (white).
- Color variation is organized hierarchically: at the microscale, blue denticles contain a tessellated reflector-absorber system (iridophores + melanophores), while white denticles lack melanophores entirely.
- At the nanoscale, ordered purine-crystal stacks (~10-60 nm features) generate narrowband blue reflection, whereas disordered assemblies produce broadband white scattering, directly linking crystal organization to optical output.
摘要: The blue shark (Prionace glauca) exhibits a striking dorsoventral color gradient, transitioning from vibrant blue dorsally to silver and white ventrally—a pattern widely interpreted as pelagic countershading. Despite its ecological significance, the physical basis of this coloration remains unresolved. Here we show that this color system does not arise from dermal chromatophores, as in most vertebrates, but from a previously unrecognised photonic architecture housed within the pulp cavity of individual dermal denticles that cover the skin. Optical imaging reveals discrete color domains within denticle crowns, while external denticle morphology remains similar across color zones. Using spectroscopy, micro-computed tomography, histology and correlative electron microscopy, we demonstrate that color variation is organized across coupled micro- and nanoscale architectures. In blue denticles, iridophores and melanophores form a densely packed tessellated reflector–absorber system within an expanded crown-restricted pulp cavity. Transition-zone denticles exhibit partial cellular layering, whereas white denticles lack melanophores and contain only reflective cells. At the nanoscale, ordered purine-crystal stacks generate narrowband blue reflection, whereas disordered assemblies produce broadband white scattering. Together, these results reveal denticles as mechanically protected optical “pixels” whose hierarchical cellular and nanocrystal organization generates the shark’s countershaded coloration.