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Wu, Z.-Y.

Publications and source records attributed to Wu, Z.-Y..

4 recordsLinked to original sources

Dynamics of Take-off in Bipedal Animals and Robots

Take-off is a fast and energy-efficient strategy for bipedal animals, such as birds, to achieve rapid movement; however, how muscle physiology scales to govern this universal behavior remains unresolved. Research in other species physiologies is not readily applicable. As a result, important questions, whether theropod dinosaurs such as Tyrannosaurus rex were capable of jumping, remain unanswered. In this article, we coupled Lagrangian dynamics with Hills muscle equations and developed new experimental methods to quantify joint rotational stiffness and damping, thereby enabling a systematic description of lower-limb mechanics. The approach establishes a novel kinetic framework that links muscle contractile properties to lower-limb performance without invoking control optimization. Animal observations and tabletop mechanisms validate the framework. The mechanics model reveals that the take-off time of about 0.1 s across body masses of 0.003 to 90 kg is achievable, as heavier birds generate proportionally higher reaction forces. Additionally, Tyrannosaurus rex should be capable of jumping, based on the available physiology data. Beyond evolutionary insights, our framework provides a new methodology for analyzing the mechanical properties of biological joints and informing the design of scalable bio-inspired robots.

biophysics↗

A pooled screening approach reveals bacterial chemoreceptors for short-chain carboxylic acids

Bacterial chemotaxis is a key process in host colonization and virulence, mediated by large repertoires of chemoreceptors. Despite their physiological and ecological importance, mapping these chemoreceptors to their cognate metabolic ligands remains a major challenge due to the vast number of potential interactions. To address this, we developed a pooled screening assay that enriches functional chemoreceptors from a gene library. Using this approach, we identified a previously uncharacterized group of chemoreceptors in Pseudomonas species with Cache_3-Cache_2 domains that sense short-chain C3 carboxylic acids. Sequence and computational structural analyses revealed that these chemoreceptors exhibit domain features similar to a recently reported C1 formate chemoreceptor despite substantial sequence divergence. Functional assays of representative chemoreceptors confirmed robust chemotactic responses to C3 carboxylic acids, with limited responses to formate. Integrating structural and molecular dynamics analyses suggests that increased binding pocket size and altered flexibility, relative to the formate chemoreceptor, facilitate recognition of larger C3 carboxylic acid ligands. Together, our approach provides a simple and scalable framework for mapping ligand-chemoreceptor interactions and enables systematic characterization across diverse metabolites.

microbiology↗

MAESTRO uncovers tandem paralog dynamics as a core driver of fungal stress adaptation

Understanding how fungi adapt to diverse stresses is critical for mitigating emerging drug resistance and harnessing their robustness for biotechnology. Pichia kudriavzevii is a stress-tolerant and intrinsically drug-resistant yeast, with dual industrial and clinical importance. We analyzed 170 strains using MAESTRO, a machine-learning-assisted GWAS pipeline optimized for small cohorts. MAESTRO identified biologically meaningful features and revealed that copy number variation (CNV) of tandem paralogs (TPs) is a core mechanism of multi-stress adaptation. TPs were recurrently linked to tolerance of industrial inhibitors (HMF, phenolics, heat) and antifungal drugs (fluconazole, azoles), and deletion of the TP pair gene4260/gene4261 confirmed pleiotropic effects across stresses. These findings support a TP CNV model where recombination-driven TP CNVs and gene fusions enable rapid stress adaptation. Importantly, our results suggest that antifungal resistance can arise through co-option of mechanisms originally evolved for environmental stressors, raising a One Health concern about the environmental origins of drug-resistant pathogens.

genomics↗

Classification of Urticaceae based on morphology and phylogenetic inference

The Urticaceae (ca. 2600 species) were first formally recognized by Jussieu in the 18th century and last comprehensively monographed by Weddell in the 19th century. Since Weddells work, family delimitation has been modified and many genera described in a fragmented manner. Over the past two decades, numerous molecular studies have supported the inclusion of Cecropiaceae within Urticaceae and identified paraphyly in several genera, notably Laportea, Urera, Boehmeria, Parietaria, Pellionia, and Pouzolzia. However, few studies have translated these molecular insights into a revised taxonomy. This study aimed to provide a robust, updated classification for Urticaceae by: a) increasing taxon and genomic locus sampling through the integration of newly generated sequence data with previously published datasets; and b) incorporating morphological data to support a revised delimitation of tribes and genera, and to establish a new linear sequence for the family. We also sought to identify remaining taxonomic challenges. Using Sanger and Angiosperms353 sequence data, we constructed a phylogenetic framework for 57 out of 59 currently accepted genera. We also assessed the phylogenetic informativeness of 57 morphological characters by mapping them onto the phylogeny. Our analyses support the delimitation of 61 monophyletic genera and an infrafamilial classification comprising seven tribes, two of which we describe as new: Myriocarpeae and Leukosykeae. We provide a revised linear sequence for the family. Our classification reinstates several names previously treated as synonyms (Fleurya, Leptocnide, Margarocarpus, Polychroa, Scepocarpus, Sceptrocnide), places several genera in synonymy (Hemistylus and Rousselia under Pouzolzia; Hesperocnide under Urtica; Gesnouinia and Soleirolia under Parietaria), and proposes the recognition of two new genera, Muimar gen. nov. and Pouzolziella gen. nov., to accommodate Boehmeria nivea and Pouzolzia australis, respectively. Mapping morphological characters onto the phylogeny indicates that while most states are homoplastic at the family level, their combination is valuable for recognizing genera. Geographic character mapping suggests a high degree of spatial conservatism at the genus rank. Our dated ultrametric tree suggests an origin for Urticaceae in Indomalaya during the mid-Cretaceous, followed by establishment in the Laurasian boreotropical flora and subsequent dispersal to the neotropics and Africa. Once classified within an evolutionary framework we believe that the Urticaceae represent a valuable study system in evolutionary biology for investigating transitions across biomes, the drivers of floral trait evolution, and intrinsic speciation mechanisms. New tribes: --Leukosykeae, Myriocarpeae New genera: --Muimar, Pouzolziella

evolutionary biology↗