Biology subjects

Yang, G.

Publications and source records attributed to Yang, G..

At least 55 records · Page 3Linked to original sources

bioRxiv2025

Transfer RNA modifications during rhizome development in Oryza longistaminata

The rhizome organ endows many clonal plants with the ability to reproduce under stressful climates. Such rhizome-mediated perenniality also underlies the recent success of perennial rice breeding. Despite the importance of this organ, its developmental regulation is poorly understood. Here, using Oryza longistaminata, an emerging model for rhizome biology, we explored the involvement of tRNA modification in rhizome development. Through comparative profiling of modified nucleotides in rhizome samples at different developmental stages and/or subjected to various treatments, we identified a number of key rhizome-related tRNA modifications and revealed that, akin to the observations in many non-plant organisms, tRNA modifications are associated with hormonal signalling to regulate rhizomes responses to environmental cues. Furthermore, genome-wide analysis of tRNA-modifying genes was performed to facilitate future functional studies. These results and analyses not only deepen our understanding of rhizome development but also underscore the regulatory roles of tRNA modification in plant organ development.

plant biology↗

bioRxiv2025

Adaptation of Perceived Animacy from Biological Motion: Evidence for a "Life Motion Detector"

Humans can readily perceive animacy from biological motion (BM) - the distinctive movement patterns of living entities. However, how the human brain extracts animacy information from BM remains largely unclear. The current study investigated this issue using visual adaptation, a non-invasive tool for revealing neural mechanisms underlying the selective processing of specific properties. Results showed that prolonged exposure to intact human walkers, compared to non-BM adaptors, biased the perception of subsequent walking stimuli towards less animate. This adaptation aftereffect persisted following adaptation to local foot motions carrying diagnostic kinematic cues, but was absent after exposure to static body forms, indicating the involvement of neuronal populations encoding animacy from BM based on motion signals. Moreover, adapting to pigeon movements also biased animacy perception for human motions, revealing a shared mechanism for encoding animacy from cross-species BM signals. These results support the existence of an inherent "life detection" system in the human brain, attuned to local foot motions and kinematic features prevalent in vertebrate movements, which may lay a foundation for perceiving life from motion across terrestrial species. Public significance statementsDiscerning whether a moving entity is animate is crucial for survival and for generating appropriate responses. This study explored how the human brain perceives animacy based on a prevalent movement pattern among vertebrates, namely, walking. Leveraging a non-invasive visual adaptation paradigm, five experiments demonstrated that pre-exposure to intact human walking, feet-only walking, and even intact pigeon walking motion sequences - but not static human forms - elicited significant adaptation aftereffects in animacy perception of human walkers. These findings support the existence of neural substrates encoding perceived animacy based on biological motion signals, particularly those carried by local foot motions and cross-species kinematic features. Such mechanisms may be integral to an inherent life detection system in the human brain.

neuroscience↗

bioRxiv2025

Mining genes underlying perennial-to-annual transitions in Oryza with comparative genomics

Perennial rice has shown great potential for alleviating multidimensional sustainability issues that are prevalent in current rice agriculture, prompting widespread interest in its breeding. Currently, one major hurdle for these breeding efforts is our scarce knowledge about the evolutionary mechanisms of the perennial-to-annual transition in Oryza. Here, by performing comparative genomics of three annual-perennial pairs of Oryza species (Oryza rufipogon/O. nivara, O. glumaepatula/O. glaberrima, and O. meyeriana/O. brachyantha), we identified 91 gene families that are present in all the perennial species but are missing in any of the annual species. Annotations and functional prediction of these gene families demonstrated that they may be associated with a battery of physiological components of perenniality, such as phenology, energy allocation, and source-sink dynamics. Furthermore, comparative co-expression analysis revealed that many of these families may also play important regulatory roles for orchestrating diverse processes that differ between perennial and annual Oryza species, including reproduction, root development, and response to environmental stimuli. These results highlight the potential complexity of the emergence of annuality in the Oryza genus and offer promising candidates for future functional studies.

plant biology↗

bioRxiv2025

Lifestyle and transcriptional signatures associated with ethnicity/race-related variations in the functional connectome

Understanding the variation of functional architecture across individuals and populations is fundamental to advancing our knowledge of human health and behaviour. Yet, while functional organization differences related to ethnicity/race are consistently reported, their underlying mechanisms remain poorly understood. Here, we apply precision individualized functional mapping to systematically investigate ethnicity/race-related differences in the brains intrinsic organization and their associations with lifestyle and transcriptional signatures. We show that variations in network topography and functional connectivity across ethnic/racial groups follow a hierarchical sensorimotor- association axis and are constrained by brain morphology. Importantly, we identify lifestyle factors-- particularly education and substance use--that significantly mediate these associations between ethnicity/race and functional connectivity. Leveraging human brain gene expression data, we further demonstrate that cortical transcriptional patterns are spatially aligned with ethnicity/race-related variability in functional connectivity. Gene ontology analyses of associated genes reveal significant enrichment in biological processes such as synaptic signalling and neuronal system development. Together, these findings uncover a multi-layered framework linking ethnicity/race-related differences in brain function to structural constraints, lifestyle influences, and molecular signatures, and advance a more comprehensive and equitable understanding of human brain diversity.

neuroscience↗

bioRxiv2025

Sister chromatid separation determines the proliferative characteristics upon whole-genome duplication through homologous chromosome rearrangement

Whole-genome duplication (WGD) of diploid cells triggers various cell fates, such as cell death, cell cycle arrest, and proliferation with chromosome instability, contributing to broad bioprocesses, including differentiation, tumorigenesis, or aging. However, factors determining the post-WGD cell fates remain largely unknown. In this study, we found that cytokinesis failure (CF) and mitotic slippage (MS), two major routes of WGD induction, differentially affected post-WGD viability and proliferation in human cells. Quantitative live imaging revealed poorer survivability of cells upon multipolar chromosome segregation at the first mitosis after MS than CF. Chromosome-specific labeling showed that the inefficient sister chromatid separation upon MS caused more skewed homologous chromosome distribution than CF. The skewed homologue distribution frequently led to physical isolation (> 10 m) of the centrosomes from all homologous centromeres, hindering these centrosomes from capturing any of these homologues. The difference in the frequency of this nullisomic chromosome segregation between MS and CF at least partially explained their difference in the viability of the subsequent daughter cells. Moreover, artificial separation of sister chromatids upon MS improved the evenness of homologue distribution, suppressed nullisomic homologue segregation in the following mitosis, and significantly restored the viability of their daughter cells. These results demonstrate the geometric arrangement of homologous chromosomes, defined by the presence or absence of sufficient sister chromatid separation upon WGD, as a key factor determining the proliferative characteristics of subsequent progenies. Our findings would provide a clue to understanding the route-dependent outcomes of WGD in cell fate determination in different bioprocesses. SignificanceWhole-genome duplication (WGD), doubling of cellular content through skipping cell division after DNA synthesis, drives cellular diversification in development, aging, tumorigenesis, or evolution. While various mechanisms of WGD are featured in different biological contexts, the potential impacts of differences in WGD mechanisms on resulting cellular properties have been overlooked. Here, we discovered that two major mechanisms of WGD, mitotic slippage and cytokinesis failure, differentially affect proliferative characteristics of post-WGD cells through their contrasting intracellular reorganizations. Mitotic slippage, occurring with inefficient sister chromatid separation, led to a skewed homologous chromosome distribution compared to cytokinesis failure, fueling lethal chromosome loss by non-random chromosome segregation immediately after WGD. Our findings provide insights into the context-dependent preferences for WGD mechanisms.

cell biology↗

bioRxiv2025

Neurodevelopmental Impact of Bipolar Disorder Genetic Risk on Cortical Thickness and Network Topology in Adolescents

Bipolar disorder (BD) is a highly heritable psychiatric condition characterized by recurrent mood episodes that commonly manifest during adolescence. Although polygenic risk scores (PRS) effectively quantify genetic susceptibility to BD, the neurobiological correlates of this genetic risk during adolescent brain development remain unclear. Using normative modeling and longitudinal neuroimaging data from the Adolescent Brain Cognitive Development (ABCD) cohort (N = 4519), we examined cortical thickness (CT) deviations and structural covariance network (SCN) alterations in adolescents stratified into high and low BD genetic risk groups based on PRS. Adolescents with high PRS for bipolar disorder exhibited greater cortical thickening in the inferior frontal gyrus and primary visual cortex, whereas those with low PRS demonstrated greater thickening in the posterior cingulate cortex and middle precentral gyrus. These patterns suggest PRS-related variations in cortical maturation, potentially reflecting distinct neurodevelopmental trajectories associated with genetic susceptibility to bipolar disorder. Furthermore, high PRS individuals displayed altered SCN topology, characterized by decreased local clustering and enhanced global network efficiency. Longitudinal data show that these abnormal regions exhibit atypical developmental trajectories, accompanied by a global reorganization of network topology. Additionally, high genetic risk was associated with lifestyle factors, especially correlated with increased positive expectancies toward substance use. Eventually, we found three potential BD risk genes during adolescence, including PLEKHA2, ZSCAN31 and ANK3, encoding the function of the postsynaptic membrane and synaptic membrane. These findings elucidate early neurodevelopmental deviations linked to genetic risk for BD, highlighting potential biomarkers for early identification and targeted interventions.

neuroscience↗

bioRxiv2025

Universal Transformer-Based Tracker for Accurate Tracking of Particles and Cells in Microscopy

Accurate tracking of subcellular structures and cells under microscopy supports heavily the studies of their dynamic processes. However, the complex motion and the similar appearances of objects pose significant challenges in accurately identifying the identical object across multiple detection results without introducing ambiguities in trajectory tracking. Here we propose a Universal Transformer-Based Tracker (UTT) that achieves the accurate tracking in various biologically relevant scenarios. The self-attention of Transformer extracts features and patterns from trajectories, and the cross-attention of Transformer captures matching relations between history tracks and future hypothesis tracklets (fragments of track). Our tracker uses the Transformer to handle the tracking of particles with diverse motion dynamics, and outperforms existing tracking algorithms in terms of accuracy. Furthermore,the tracker utilizes estimated particle positions to counteract missed detections, thereby improving tracking robustness under varying ratios of missing detections. We demonstrate the flexibility and versatility of our approach by adaptively integrating motion and appearance cues in cell tracking applications.

bioinformatics↗

bioRxiv2025

Acute session of three endurance exercise intensities alters subcutaneous adipose tissue transcriptome in regular exercisers

The primary aim of this study was to compare the acute effects of three exercise intensities on abdominal subcutaneous adipose tissue (aSAT) transcriptome in regular exercisers. A total of 45 adults who exercise regularly were assigned to perform a single session of either low-intensity continuous (LOW; 60min at 30% VO2max; n=15), moderate-intensity continuous (MOD; 45min at 65% VO2max; n=15), or high-intensity interval exercise (HIGH; 10x1min at 90% VO2max interspersed with 1min active recovery; n=15). aSAT biopsy samples were collected before and 1.5hours after the exercise session for bulk RNA sequencing and targeted protein immunoassays. HIGH upregulated genes involved in cytokine secretion, insulin signaling, and proteolysis while MOD and LOW upregulated genes regulating ECM remodeling, ribosome biogenesis, and oxidative phosphorylation pathways. Exercise-induced changes in aSAT angiogenic, MAPK cascade, and clock genes, ERK protein phosphorylation, and circulating cytokines were similar after all three exercise treatments. Network analysis identified exercise-responsive gene clusters linked to cardiometabolic health traits. Cell-type analysis highlighted a heterogeneous response of aSAT cell types to exercise, with distinct patterns observed across exercise intensities. Collectively, our data characterizes early responses in aSAT after a single session of exercise. Because adaptations to exercise training stem from an accrual of responses after each session of exercise, these early responses to exercise are likely important contributors to the long-term structural and functional changes that occur in adipose tissue in response to exercise training.

physiology↗

bioRxiv2025

Bridging Hearts and Muscles: Genetic Insights into Cardiac Structure and Sarcopenia

BackgroundCurrently, the link between cardiovascular diseases and sarcopenia is increasingly garnering attention from researchers. However, studies exploring the association between cardiac structure and sarcopenia are sparse. This study aims to investigate the potential genetic links between cardiac structural features and sarcopenia. MethodsDuring the discovery phase, we employed Linkage Disequilibrium Score Regression (LDSC) and Mendelian Randomization (MR) to assess the genetic correlation and causality between traits related to cardiac structure and sarcopenia, with further validation of the results using validation set data. In the study, we established a scoring system to identify high-confidence trait pairs. For these pairs, we conducted sensitivity analyses to assess their heterogeneity and pleiotropy. Additionally, we undertook follow-up studies of these trait pairs, including using mediation analysis to evaluate the potential mediating effects of lipids, and enrichment analysis to explore possible shared biological pathways linking these characteristics. ResultsThe genetic correlation analyses during the discovery and validation phases identified 5 pairs (in forward analysis) and 16 pairs (in reverse analysis) of high-confidence trait pairs. As a key sarcopenia-related feature, appendicular lean mass (ALM) exhibited positive causal relationships with several cardiac structural features, including the volumes of the left and right atria. Mediation analysis suggested that certain lipids, such as phosphatidylcholine, might mediate these causal relationships. Notably, gene and pathway enrichment analyses revealed that genes associated with significant SNPs in high-confidence trait pairs were enriched in multiple key biological processes and pathways, such as tube morphogenesis, cardiac right ventricle morphogenesis, and muscle system processes in the forward analysis, as well as skeletal system development, heart development, and hemopoiesis in the reverse analysis. Cell-type enrichment analysis pointed to endothelial cells, smooth muscle cells, fibroblasts, and mesenchymal stem cells. ConclusionsThis study provides evidence for genetic relationships between cardiac structures and sarcopenia-related traits. These findings may enhance our understanding of the biological mechanisms underlying age-related diseases and provide scientific basis for developing future preventive and therapeutic strategies.

genetics↗

bioRxiv2025

A Novel No-Wash (Homogenous) High-Throughput Toxicity Assay on Primary Cells

Mitochondrial membrane potential (MMP) is a critical marker of mitochondrial and, therefore, cellular function. However, current dyes used for MMP measurement possess significant limitations: nonspecific targeting, long incubation times, potential mitochondrial toxicity, poor water solubility, and numerous wash steps. Using a novel fluorescent dye--mitochondrial membrane potential indicator (m-MPI)--in combination with a masking dye, we overcame said limitations and successfully measured MMP changes on different cell lines, as well as four different human primary cells. This no-wash assay has been miniaturized into a 384-well format. It is robust with Z value > 0.5 on both HepG2 and HeLa cells and can be used for high throughput screening. The reagents in the m-MPI homogeneous assay kit are not toxic to cells, as was demonstrated on HepG2 and HeLa cell lines using Dexorgens EnerCount ATP assay. Using this assay, we conducted a mini screening on human hepatocytes against the Library of Pharmacologically Active Compounds (LOPAC) (Sigma). The resulting hits were then confirmed with follow-up studies.

cell biology↗

bioRxiv2025

SCARF: Single Cell ATAC-seq and RNA-seq Foundation model

Recent advances in single-cell multi-omics have provided unprecedented insights into gene regulation by jointly profiling transcriptomic (scRNA-seq) and chromatin accessibility (scATAC-seq) landscapes. However, the inherent heterogeneity and high dimensionality of these multimodal data present significant challenges for effective integration and downstream analysis. Foundation models have demonstrated strong representation learning capabilities for scRNA-seq or scATAC-seq data. So far, however, no model has been specifically developed for the integrative analysis of these two modalities. Here, we introduce SCARF, a single cell ATAC-seq and RNA-seq foundation model. SCARF is pre-trained on X-Omics, the largest curated collection of single-cell multi-omics data to date, comprising over 2.7 million cells across multiple tissues and species. The model utilizes a Mamba architecture for efficiently capturing long-context relationships between genes and between accessible regions. Modality-specific and shared features are learned by the model through self-supervised learning and contrastive learning, respectively. SCARF achieves state-of-the-art performance on multiple downstream tasks, including cell representation, cell matching, and cross-omics translation. Furthermore, SCARF enables few-shot cell type annotation, demonstrating strong generalizability across previously unseen datasets. These results highlight the power of foundation models for advancing integrative analysis of single cell multi-omics data, with broad applications in important tasks including cellular characterization, gene or genomic perturbation analysis, and regulation network analysis.

bioinformatics↗

bioRxiv2025

Two telomere-to-telomere, gap-free genome assemblies and comparisons revealed the conserved key genes associated with sugar accumulation in Rubus genus

For the first time, we assembled two highly continuous, completely gap-free reference genomes of the Rubus subgenus: Rubus hirsutus Thunb. Penglei (XMM) and Rubus eustephanos Focke ex Diels Dahongpao (DHP), which are widely distributed in southern China with similar phenotypic traits (Figures 1A, 1B, and Figure S1), yet ripe fruits display distinct sugar accumulation levels (Table S1), making them ideal candidates for investigating the mechanisms underlying sugar accumulation in the Rubus genus. The XMM (213.53 Mb, 28,204 genes) and DHP (218.26 Mb, 28,569 genes) genomes exhibit close evolutionary relationships, diverging approximately 3.21 Mya. Comparative genomics identified extensive synteny, interspecific structural variations (translocations, inversions, segmental duplications), and presence/absence variation (PAV). Using Hi-C interaction heatmaps and Sanger sequencing, we validated interspecific structural inversions. Additionally, we identified a sugar transporter gene (MFS1), which is present in XMM but absent in DHP. Combined analysis of the gene family expansion/contraction and transcriptome identified two conserved key genes (RhSTP13 and RhSTP7) associated with sugar accumulation in Rubus genus and displayed distinct roles through transient expression assay. To facilitate functional genomics study, we also established a comprehensive Rubus database, RubusDB, a freely accessible repository consolidating all genomic, transcriptomic and phenotypic data of Rubus genus. These findings provide a foundational framework for elucidating the genetic basis of sugar accumulation, genome diversification, and trait improvement in Rubus species. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=170 SRC="FIGDIR/small/646780v2_fig1.gif" ALT="Figure 1"> View larger version (72K): org.highwire.dtl.DTLVardef@1baca20org.highwire.dtl.DTLVardef@2c01eaorg.highwire.dtl.DTLVardef@131dc00org.highwire.dtl.DTLVardef@62a04f_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFIGURE 1.C_FLOATNO Phenotypic characterization, de novo genome assemblies, variation, and evolution of Rubus hirsutus Thunb. Penglei (XMM) and Rubus eustephanos Focke ex Diels Dahongpao (DHP). (A) Illustration of XMM whole plants, stem, flower bud and flower, respectively. (B) Illustration of DHP whole plants, stem, flower bud and flower, respectively. (C) The chromosome karyotype analysis of XMM. Bar = 10 {micro}m. (D) Circular diagram of XMM and DHP reference genomes. (a) Chromosomes are represented by centromeres (dark red) and telomeres (blue); (b) CEN18 density; (c) CEN17 density; (d) Gene density; (e) TE density; (f) PAV density; (g) SNP density; (h) Collinear lines at the center of diagram highlight homoeologous chromosomes relationships and non-homoeologous regions. (E) Genomic alignments between XMM and DHP. Inversions, duplications and translocations are marked with orange, blue and green ribbons, respectively. (F) Identification of large inversions in chromosome 7 between XMM and DHP. The three heatmaps show the chromatin interaction matrix, including mapping Hi-C data of DHP against DHP genome (left), mapping Hi-C data of DHP against XMM genome (middle) and mapping Hi-C data of XMM against XMM genome (right). The lower panel illustrates gene alignments between XMM and DHP. (G) Synteny, structural rearrangements, monomer, and identity distribution in the 16-20 Mbp region of chromosome 6 between XMM and DHP. (H) Local genome synteny of chromosome 5, with a structural variation that is present only in XMM. The PAV region includes a gene related to sugar transporter (MFS1, XMM05G025540). (I) Gene-level matchings of MFS genes in the PAVs region between XMM and DHP. (J) Phylogenetic relationships and divergence times between raspberries and other Rosaceae species. The black numbers close to the divergence nodes indicate the divergence times and the red bars represent the 95% confidence intervals. The red and black numbers indicate expanded and contracted ortholog groups at the corresponding node. Scale bar corresponds to 10 Mya. C_FIG

genomics↗

bioRxiv2025

Adolescents with major depression featured by sensory-association subtyping show divergent information dynamics and streams

Adolescent major depressive disorder (MDD) exhibits complex and heterogeneous alterations of brain functional organization. To understand the neurobiological basis of adolescent MDD, we adopted resting-state functional MRI data and used various matrix decomposition approaches to obtain the organization gradients, temporal dynamics, and information streams. With clustering sensory-association gradient features in our exploratory sample (NMDD = 250 and NControls = 203), we identified two MDD subtypes. Subtype 1 was characterized by sensory contraction and subtype 2 was associated with association expansion. In addition, two subtypes showed divergent bottom-up and top-down information flows in sensory and association areas using temporal dynamics analysis. These subtypes exhibit distinct age-related changes and reorganization trajectories along sensory-association and auditory-visual axes, highlighting that cortical information flow patterns systematically vary and relate differently to sensory integration, cognitive complexity, and aging. These network distinctions are linked to clinical severity and molecular mechanisms. Subtype 1 is predominantly associated with early neurodevelopmental abnormalities and emotional regulation deficits, while Subtype 2 is more related to synaptic dysfunction and reduced neuronal excitability. These results could be largely replicated in another independent sample (NMDD = 73 and NControls = 28). We therefore construct a sensory-association dual functional framework to characterize MDD heterogeneity in adolescent MDD. Itl integrates cortical hierarchy, developmental trajectories, and genetic influences, offering novel insights into MDD pathophysiology and providing a theoretical foundation for precision psychiatry, facilitating personalized diagnosis and intervention strategies.

neuroscience↗

bioRxiv2025

Asymmetric Histone Inheritance Regulates Differential Transcription Re-initiation and Cell Fate Decisions in Mouse Olfactory Horizontal Basal Cells

The olfactory epithelium (OE) possesses an adult stem cell population, the horizontal basal cells (HBCs), to permit lifelong tissue regeneration. Here we show that HBCs exhibit asymmetric inheritance of histone H4 but not H2A-H2B during OE regeneration in mice. Primary HBC cultures further revealed asymmetric histone inheritance for H3 and H3.3. Upon mitotic exit, asymmetric histone inheritance correlates with asynchronous transcription re-initiation and differential enrichment of p63, a key transcription factor for HBC cell fate. Disruption of asymmetric histone inheritance abolished these asymmetric cellular features and attenuated OE regeneration and smell behavior recovery. Single-cell RNA sequencing of paired HBC daughters in culture further supported asymmetric multilineage cell fate priming. Together, these findings reveal asymmetric histone inheritance in a mammalian adult stem cell lineage and highlight its biological significance in neural tissue regeneration and animal behavior.

developmental biology↗

bioRxiv2025

Characterization and description of Clostridium filamentum ETTB, a novel gut bacterium with TLR5 modulating properties

The Clostridium genus is highly heterogeneous, encompassing numerous species and strains, many of which remain to be isolated and characterized to better understand their relationship to host physiology. This study aimed to isolate and characterize novel bacterial species within the Clostridium genus and explore their potential links to host health. Under microaerophilic conditions, we isolated and characterized three bacterial isolates belonging to a new anaerobic Clostridium species, designating Clostridium sp. DSM 115107 (Clostridium filamentum ETTB3) as the type strain. C. filamentum ETTB isolates are rod- to filament-shaped, Gram-positive bacteria and exhibit poor growth when cultured on rich media such as LYBHI. Genome sequencing and phylogenetic analysis revealed that C. filamentum ETTB belongs to the Clostridium genus and clusters closely with Clostridium saudiense JCC. Interestingly, C. filamentum ETTB has a significantly smaller genome compared to C. saudiense JCC containing a reduced repertoire of genes involved in carbohydrate degradation and amino acid synthesis and a larger number of genes related to cell motility, including an additional copy of the fliC gene. Unlike C. saudiense, C. filamentum ETTB adopted a filamentous morphology when in contact with Caco-2 cells and stimulate the TLR5 pathway in Caco-2 cells. Metagenomics analysis revealed that C. filamentum ETTB is present in both industrialized and non-industrialized populations, although the relative abundance varying considerably between and within individuals. Our study identifies a novel bacterial strain adapted for the human gut that has the potential to influence host immune response by activating TLR5 pathway.

microbiology↗

bioRxiv2025

From Local Interactions to Global Patterns: An Analysis of Silk Density in Spider Webs

This study explores the structural complexity of spider webs through information-theoretic and harmonicity-based frameworks to quantify spatial patterns in silk density across different web regions and reveal the underlying resource allocation strategies. Currently, there is no normalized approach for describing web structure and complexity, particularly for sheet-webs, and this methodology allows for non-destructive scanning and quantification of web characteristics. By analyzing the entropy of silk density distributions, a single scalar that captures the heterogeneity of material investment across the entire web, we observed that the entropy values follow a normal distribution with a mean of 1.24 {+/-} 0.22 bits when using 10 quantization levels. In the second part of the paper, by measuring the harmonicity of the silk density, we reveal that the silk density at a given point can be inferred from its neighbors, with an average harmonicity value of 0.0039 {+/-} 0.0017 (fraction of total points in point cloud data). The harmonic behavior is notable for its maximum principle, suggesting that the strongest parts of the web appear at the boundaries, aligning with existing knowledge of spider web construction. These findings provide a new technique for quantifying web-building strategies and offer new insights into spider behavior and evolution.

animal behavior and cognition↗

bioRxiv2025

MeQTL Mapping in African American Hepatocytes Reveals Shared Genetic Regulators of DNA Methylation and Gene Expression

Methylation quantitative trait loci (meQTL) mapping can provide insight into the genetic architecture underlying the epigenome by identifying single-nucleotide polymorphisms (SNPs) associated with differential methylation at methylation sites (CpGs) across the genome. Given that the epigenetic architecture underlying differences in gene expression can vary across racial populations, performing epigenomic studies in African Americans is crucial for understanding the interplay between genetic variation, DNA methylation, and gene expression in this understudied group. By performing cis-meQTL mapping in African American hepatocytes, we identified 410,186 cis-meQTLs associated with methylation at 24,425 CpGs in the liver. Through colocalization analysis, we found that 18,206 of these meQTLs are also colocalized with known liver eQTLs. Additionally, we found that using African American eQTL data results in an increased ability to detect additional colocalized variants that exhibit strong differences in allele frequency between people of European and African ancestry. Furthermore, the presence of smaller linkage disequilibrium blocks in African Americans allows us to identify narrower genomic regions of potentially causal variants compared to when data from Europeans is used. Importantly, these colocalized SNPs are significantly enriched for genetic associations with lipid and inflammatory traits in the GWAS catalog, suggesting that DNA methylation may contribute to the etiologies of these diseases. Furthermore, while it is generally presumed that the genetic regulation of DNA methylation is shared between blood and liver, we found that only 5.4% of African American liver meQTLs colocalize with blood meQTLs. Overall, our results reveal that studying African American populations results in the identification of additional genetic and epigenetic factors that may regulate gene expression in the liver, thereby expanding our understanding of gene regulation in African Americans.

genomics↗

bioRxiv2024

ISCO: Intelligent Framework for Accurate Segmentation and Comparative Analysis of Organoids

Organoids are self-organizing 3D cell clusters that closely mimic the structure and function of in vivo tissues and organs. Quantifying organoid morphology is critical for advancing our understanding of organ development, drug discovery, and toxicity assessment. Recent advances in microscopy have provided powerful tools to capture detailed morphological features of organoids, yet manual image analysis remains labor-intensive and time-consuming. In response, we present a comprehensive microscopy-based analysis pipeline that utilizes SegmentAnything 2.1 to accurately segment individual organoids. Additionally, we introduce a suite of morphological features--including perimeter, area, radius, non-smoothness, and non-circularity--that enable researchers to quantitatively and automatically analyze organoid structures. To further standardize organoid analysis across the field, Intelligent segmentation and comparison of organoids(ISCO), an intelligent AI-driven open-source algorithm, is developed with the aim of establishing a comprehensive toolset for organoid characterization.

bioengineering↗