Biology subjects

Zhu, D.

Publications and source records attributed to Zhu, D..

At least 55 records · Page 3Linked to original sources

bioRxiv2025

Metabolomics biomarkers of frailty: a longitudinal study of aging female and male mice

Frailty is an age-related geriatric syndrome, for which the mechanisms remain largely unknown. We performed a longitudinal study of aging female (n = 40) and male (n = 47) C57BL/6NIA mice, measured frailty index and derived metabolomics data from plasma samples. We identify differentially abundant metabolites related to aging, determine frailty related metabolites via a machine learning approach, and generate a union set of frailty features, both in the whole cohort and in sex-stratified subgroups. Using the features, we perform an association study and build a metabolomics-based frailty clock. We find that frailty related metabolites are enriched for amino acid metabolism and metabolism of cofactors and vitamins, include ergothioneine, tryptophan, and alpha-ketoglutarate, and present sex dimorphism. We identify B vitamin metabolism related flavin adenine dinucleotide and pyridoxate as female-specific frailty biomarkers, and lipid metabolism related sphingomyelins, glycerophosphoethanolamine and glycerophosphocholine as male-specific frailty biomarkers. These associations are confirmed in a validation cohort, with ergothioneine and perfluorooctanesulfonate identified as robust frailty biomarkers. In summary, our results identify sex-specific metabolite biomarkers of frailty in aging, and shed light on potential mechanisms involved in frailty.

biochemistry↗

bioRxiv2025

Coexistence of Virome-Encoded Human Probiotic Genes and Pathogenic Genes in Global Habitats

Some probiotic genes for humans obtained through horizontal gene transfer (HGT) have been screened in viral genomes, yet the occurrence mode, geographic distribution, and functional characteristics of these genes in viruses and the coexistence between pathogenic virulence genes and probiotic genes in the viral genome, remain insufficiently understood and verified. In this study, using IMG/VR v4 database, 4,556 viruses carrying probiotic gene segments have been discovered in eight habitat types (humans, animals, freshwater, marine, other water bodies, soil, and plants), 13 regions of 76 countries around the world. Among them, the 478 viruses carrying probiotic genes that distributed in humans account for the highest proportion among the viruses with predictable hosts. In viruses carrying probiotic genes, BCO1, bioB, COQ2, GPX1, GSTs, GSTT1, GULO, and menA are not only probiotic genes encoded by viruses, but also auxiliary metabolic genes. Four virulence genes harmful to humans in viral sequences carrying probiotic genes with transcription and expression potential, have been found, indicating that virulence genes encoded by viruses can coexist with probiotic genes. Further metagenome sequencing revealed the consistency between the probiotic gene asd in the bacillus prophage and the corresponding phage auxiliary metabolic genes. This study integrates probiotic gene databases into viral genomics, revealing the compatibility between viral probiotic and virulence genes, and offering new insights for viral applications. IMPORTANCEProbiotic genes acquired by humans through horizontal gene transfer (HGT) have been identified within viral genomes. However, their occurrence, distribution, and functions, along with the coexistence of pathogenic and probiotic genes in viruses, remain poorly understood. This study advocates for the utilization of probiotic gene databases in viral genomes and innovatively elucidates the phenomenon of compatibility between viral probiotic genes and virulence genes, offering fresh perspectives on the diverse applications of viruses. By promoting the application of these databases, the study reveals the compatibility between probiotic and pathogenic genes in viruses, providing novel and insightful implications for the various utilizations of viruses.

bioinformatics↗

bioRxiv2024

LINC00599 Promotes Pulmonary Hypertension via LLPS with G3BP1 and MYH9

BACKGROUNDPulmonary hypertension (PH) represents a significant cardiovascular disorder marked by both functional and structural alterations within the pulmonary vasculature. Long non-coding RNAs (lncRNAs) have been closely associated with the pathogenesis and progression of PH. Nonetheless, the precise mechanisms by which lncRNAs interact with its downstream target molecules to modulate the disease remain inadequately elucidated. METHODSThe expression levels of LINC00599 were quantified in the lung tissues of mice and pulmonary arterial smooth muscle cells (PASMCs) under hypoxic conditions. The involvement of LINC00599 in the progression of PH and vascular remodeling was evaluated through in vivo studies. To investigate the mechanisms by which LINC00599 influences the proliferation of human PASMCs, small interfering RNA and overexpression plasmids were employed. RESUITSThe expression of LINC00599 is upregulated in the medial layer of pulmonary arteries in experimental models of PH and in hypoxic PASMCs. Administration of a single dose of lentivirus-mediated shRNA targeting LINC00599 effectively reverses hypoxic PH in murine models. LINC00599 plays a critical role in PASMC proliferation by modulating stress granule formation through N6-methyladenosine (m6A) modification and promoting proliferation via liquid-liquid phase separation with myosin heavy chain 9. Furthermore, the expression of LINC00599 is regulated by a super-enhancer, which is mediated by the transcription factor ZNF263. CONCLUSIONSThese findings demonstrate for the first time that LINC00599, involved in liquid-liquid phase separation, facilitates the progression of pulmonary hypertension by enhancing the proliferation of pulmonary artery smooth muscle cells. GRAPHIC ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=158 SRC="FIGDIR/small/629439v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@7ac192org.highwire.dtl.DTLVardef@13a88b3org.highwire.dtl.DTLVardef@1e4c761org.highwire.dtl.DTLVardef@ddd105_HPS_FORMAT_FIGEXP M_FIG C_FIG What Is New?This study identified LINC00599 as a critical regulator of liquid-liquid phase separation through m6A modification and as a pivotal target in promoting the progression of PH. What Is Relevant?LncRNAs are intricately associated with the pathogenesis and progression of PH through the modulation of downstream target molecules. However, it remains unclear whether lncRNAs contribute to PH by forming specific subcellular structures with these target molecules. Furthermore, some studies have suggested that the increased presence of stress granules in PASMCs is implicated in the pathogenesis of pulmonary arterial hypertension. In this study, we provide evidence that LINC00599 promotes the development of PH by forming stress granules with its target proteins. Our findings indicate that the binding of LINC00599, modified with m6A, to G3BP1 and MYH9 in PASMCs suggests that the regulation of liquid-liquid phase separation by lncRNA m6A modification may represent a significant pathological mechanism underlying PH. What Are the Pathophysiological Implications?We found that LINC00599 levels were elevated in hypoxic PASMCs and experimental PH models. Knockout LINC00599 effectively prevented PH, indicating its potential as both a bomarker and therapeutic target for PH.

physiology↗

bioRxiv2024

Optimizing Angiopep-2 Density on Polymeric Nanoparticles for Enhanced Blood-Brain Barrier Penetration and Glioblastoma Targeting: Insights from In Vitro and In Vivo Experiments

The blood-brain barrier (BBB) poses a formidable challenge to efficient drug delivery into the brain. One promising approach involves leveraging receptor-mediated transcytosis facilitated by Angiopep-2 peptide (Ang-2)-conjugated nanoparticles. However, the precise impact of Ang-2 density on BBB penetration remains poorly understood. In this study, we developed a versatile polymeric nanoparticle system with tuneable Ang-2 surface density and systemically examined its influence on BBB penetration through various in vitro assays and an in vivo study. Our findings revealed a nuanced relationship between Ang-2 surface density and BBB penetration across the different experimental setups. In 2D cell culture, we observed a positive correlation between Ang-2 surface density and cellular association in hCMEC/D3 cells, characterized by a distinctive inflection point. Conversely, in the Transwell model, higher Ang-2 density correlated negatively with BBB penetration, whereas the BBB-GBM-on-a-chip showed the opposite trend. These disparities may arise from differences in avidity under static versus dynamic conditions, potentially modulating nanoparticle interactions due to fluidic forces. In vivo studies revealed that higher Ang-2 densities facilitated nanoparticle transport across the BBB, consistent with the findings of the BBB-GBM-on-a-chip model. Furthermore, loading doxorubicin into nanoparticles with optimal Ang-2 density resulted in controlled pH-responsive release and enhanced anticancer effect against U87 GBM cells in both 2D cell cultures and a 3D BBB-GBM-on-a-chip model. These results underscore the critical importance of optimizing Ang-2 surface density for efficient BBB penetration and emphasize the utility of dynamic models in preclinical in vitro assessment of novel nanoparticle formulations for targeted delivery to the brain.

bioengineering↗

bioRxiv2024

Butterfly brains change in morphology and in gene splicing patterns after brief pheromone exposure

How insect brains differ between the sexes and respond to sex-specific pheromones is still not well understood. Here we briefly exposed female Bicyclus anynana butterflies to wild type (Wt) and modified male sex pheromone blends, previously shown to modify females sexual preferences, and examined how their brains were modified at the morphological and molecular levels, three days later. First, we 3D-reconstructed male and female brains of this species and documented sexual dimorphism in the size of seven of 67 glomeruli present in the olfactory lobe. Then we showed that several glomeruli changed in volume after blend exposures, implicating them in sex pheromone perception. Finally, we found that a few genes were differentially expressed but many more were differentially spliced between male and female naive brains, and between naive and pheromone blend-exposed brains. These are primarily calcium-binding channels and RNA-binding genes, respectively. A learned preference for changed levels in a single pheromone component was linked to variants of proteins involved in synaptic transmission. Our work shows that naive male and female brains differ primarily in gene splicing patterns and that a brief, 3-minute, exposure to pheromones produces slight changes in brain volume and large changes in the splicing of genes involved in neural development, that correlate with changes in sexual preferences in females. Significance statementHow brains differ between the sexes and respond to sex-specific cues is a hot research topic. Here we investigate how the brains of female butterflies differ from those of males and respond to male sex pheromones. We find that the sexes differ in the volume of a sub-set of olfactory lobe glomeruli, and the volume of some glomeruli also changes after exposure to pheromone blends. In addition, male and female brains differ primarily in hundreds of splice variants, both before and after pheromone exposure. These findings suggest that different proteins (splice variants) characterize male and female brains and that a brief exposure to pheromones can lead to changes in brain structure and in further gene splicing linked to altered sexual preferences in female butterflies.

animal behavior and cognition↗

bioRxiv2024

Overabundant endocannabinoids in neurons are detrimental to cognitive function

2-Arachidonoylglycerol (2-AG) is the most prevalent endocannabinoid involved in maintaining brain homeostasis. Previous studies have demonstrated that inactivating monoacylglycerol lipase (MAGL), the primary enzyme responsible for degrading 2-AG in the brain, alleviates neuropathology and prevents synaptic and cognitive decline in animal models of neurodegenerative diseases. However, we show that selectively inhibiting 2-AG metabolism in neurons impairs cognitive function in mice. This cognitive impairment appears to result from decreased expression of synaptic proteins and synapse numbers, impaired long-term synaptic plasticity and cortical circuit functional connectivity, and diminished neurogenesis. Interestingly, the synaptic and cognitive deficits induced by neuronal MAGL inactivation can be counterbalanced by inhibiting astrocytic 2-AG metabolism. Transcriptomic analyses reveal that inhibiting neuronal 2-AG degradation leads to widespread changes in expression of genes associated with synaptic function. These findings suggest that crosstalk in 2-AG signaling between astrocytes and neurons is crucial for maintaining synaptic and cognitive functions and that excessive 2-AG in neurons alone is detrimental to cognitive function.

neuroscience↗

bioRxiv2024

Dynamics of duplicated gene regulatory networks governing cotton fiber development following polyploidy

Cotton fiber development entails complex genome-wide gene regulatory networks (GRN) that remain mostly unexplored. Here we present integrative analyses of fiber GRNs using public RNA-seq datasets, integrated with multi-omics genomic, transcriptomic, and cistromic data. We detail the fiber co-expression dynamics and regulatory connections, validating findings with external datasets and transcription factor (TF) binding site data. We elucidate previously uncharacterized TFs that regulate genes involved in fiber-related functions and cellulose synthesis, and identify the regulatory role of two homoeologous G2-like transcription factors on fiber length. Analysis of duplicated gene expression and network relationships in allopolyploid cotton, which has two co-resident genomes (A, D), revealed novel aspects of asymmetric subgenomic developmental contributions. Whereas D-based homoeolog pairs drive higher overall gene expression from the D subgenome, TFs from the A subgenome play a preferential regulatory role in the fiber gene regulatory network. Following allopolyploid formation, it appears that the trans-regulatory roles of TFs diversified more rapidly between homoeologs than did the cis-regulatory elements of their target genes. Our approach underscores the utility of network analysis for detection of master regulators and provides fresh perspectives on fiber development and polyploid functional genomics, through the lens of co-expression and GRN dynamics.

bioinformatics↗

bioRxiv2024

An application of the MR-Horse method to reduce selection bias in genome-wide association studies of disease progression

Genome-wide association studies (GWAS) of disease progression are vulnerable to collider bias caused by selection of participants with disease at study entry. This bias introduces spurious associations between disease progression and genetic variants that are truly only associated with disease incidence. Methods of statistical adjustment to reduce this bias have been published, but rely on assumptions regarding the genetic correlation of disease incidence and disease progression which are likely to be violated in many human diseases. MR-Horse is a recently published Bayesian method to estimate the parameters of a general model of genetic pleiotropy in the setting of Mendelian Randomisation. We adapted this method to provide bias-reduced GWAS estimates of associations with disease progression, robust to the genetic correlation of disease incidence and disease progression and robust to the presence of pleiotropic variants with effects on both incidence and progression. We applied this adapted method to simulated GWAS of disease incidence and progression with pleiotropic variants and varying degrees of genetic correlation. When significant genetic correlation was present, the MR-Horse method produced less biased estimates than unadjusted analyses or analyses adjusted using other existing methods. Type 1 error rates with the MR-Horse method were consistently below the nominal 5% level, at the expense of a modest reduction in power. We then applied this method to summary statistics from the CKDGen consortium GWAS of kidney function decline. MR-Horse attenuated the effects of variants with known likely biased effects in the CKDGen GWAS, whilst preserving effects at loci with likely true effects.

genetics↗

bioRxiv2024

Mechanical evolution of metastatic cancer cells in three-dimensional microenvironment

Cellular biomechanics plays critical roles in cancer metastasis and tumor progression. Existing studies on cancer cell biomechanics are mostly conducted in flat 2D conditions, where cells behavior can differ considerably from those in 3D physiological environments. Despite great advances in developing 3D in vitro models, probing cellular elasticity in 3D conditions remains a major challenge for existing technologies. In this work, we utilize optical Brillouin microscopy to longitudinally acquire mechanical images of growing cancerous spheroids over the period of eight days. The dense mechanical mapping from Brillouin microscopy enables us to extract spatially resolved and temporally evolving mechanical features that were previously inaccessible. Using an established machine learning algorithm, we demonstrate that incorporating these extracted mechanical features significantly improves the classification accuracy of cancer cells, from 74% to 95%. Building on this finding, we have developed a deep learning pipeline capable of accurately differentiating cancerous spheroids from normal ones solely using Brillouin images, suggesting the mechanical features of cancer cells could potentially serve as a new biomarker in cancer classification and detection.

biophysics↗

bioRxiv2024

Long-term NMN treatment increases lifespan and healthspan in mice in a sex dependent manner

Nicotinamide adenine dinucleotide (NAD) is essential for many enzymatic reactions, including those involved in energy metabolism, DNA repair and the activity of sirtuins, a family of defensive deacylases. During aging, levels of NAD+ can decrease by up to 50% in some tissues, the repletion of which provides a range of health benefits in both mice and humans. Whether or not the NAD+ precursor nicotinamide mononucleotide (NMN) extends lifespan in mammals is not known. Here we investigate the effect of long-term administration of NMN on the health, cancer burden, frailty and lifespan of male and female mice. Without increasing tumor counts or severity in any tissue, NMN treatment of males and females increased activity, maintained more youthful gene expression patterns, and reduced overall frailty. Reduced frailty with NMN treatment was associated with increases in levels of Anerotruncus colihominis, a gut bacterium associated with lower inflammation in mice and increased longevity in humans. NMN slowed the accumulation of adipose tissue later in life and improved metabolic health in male but not female mice, while in females but not males, NMN increased median lifespan by 8.5%, possible due to sex-specific effects of NMN on NAD+ metabolism. Together, these data show that chronic NMN treatment delays frailty, alters the microbiome, improves male metabolic health, and increases female mouse lifespan, without increasing cancer burden. These results highlight the potential of NAD+ boosters for treating age-related conditions and the importance of using both sexes for interventional lifespan studies.

pharmacology and toxicology↗

bioRxiv2024

Multi-omics reveals AKR1B1-regulated galactose metabolic as a driver of gastrointestinal stromal tumor progression

The underlying mechanism of malignant progression in gastrointestinal stromal tumors (GISTs) is not fully understood. Despite recent advancements, a comprehensive profile of metabolome, transcriptome, and proteome of GISTs is lacking. This study conducted an integrated multi-omics analysis of GISTs across different risk classifications. By integrating metabolomics, transcriptomics, and proteomics, we identify distinct metabolic patterns and associated biological pathways implicated in the malignant progression of GISTs. Moreover, we identified galactose metabolism and the pivotal rate-limiting enzyme AKR1B1 is dysregulated in GISTs progression. AKR1B1 was upregulated and predicted poor prognosis in GISTs. In addition, AKR1B1 knockdown resulted in trehalose accumulation in GIST cells, thereby inhibiting cell proliferation and mitosis. These findings not only enhance our comprehension of the underlying mechanisms governing GIST progression from a metabolic reprogramming standpoint but also furnish prognostic biomarkers and potential therapeutic targets for GISTs.

cancer biology↗

bioRxiv2024

Amyloid beta glycation leads to neuronal mitochondrial dysfunction and Alzheimers pathogenesis through VDAC1-dependent mtDNA efflux

Glycation, the non-enzymatic attachment of reactive dicarbonyls to proteins, lipids, or nucleic acids, contributes to the formation of advanced glycation end-products (AGEs). In Alzheimers disease (AD), amyloid-beta (A{beta}) undergoes post-translational glycation to produce glycated A{beta} (gA{beta}), yet its pathological role remains poorly understood. Here, we demonstrate that gA{beta} promotes neuronal mitochondrial DNA (mtDNA) efflux via a VDAC1-dependent mechanism, activating the innate immune cGAS-STING pathway. Using aged AD mice and human AD brain samples, we observed cGAS-mtDNA binding and cGAS-STING activation in the neuronal cytoplasm. Knockdown of RAGE, cGAS, or STING, as well as pharmacological inhibition of VDAC1, protected APP mice from mitochondrial dysfunction and Alzheimers-like pathology. Neuron-specific cGAS knockdown confirmed its pivotal role in driving neuroinflammation and cognitive deficits. Treatment with ALT-711, an AGE cross-link breaker, alleviated gA{beta}-associated pathology. Furthermore, RAGE inhibition in APP knock-in mice suppressed innate immune activation and disease-associated gene expression, as revealed by spatially resolved transcriptomics. Collectively, our findings establish a mechanistic link between gA{beta} and innate immune activation, identifying VDAC1, the AGE-RAGE axis, and the cGAS-STING pathway as promising therapeutic targets in AD. Significance StatementThis study reveals how a modified form of amyloid-beta disrupts mitochondrial function in neurons, triggering innate immunity and disease progression. We show that this modified amyloid-beta damages mitochondria, activating a specific immune response in the brain. By identifying the key molecules involved, we provide potential targets for new Alzheimers treatments aimed at preventing mitochondrial damage and cognitive decline. This research offers fresh insights into Alzheimers development and highlights new therapeutic pathways.

neuroscience↗

bioRxiv2024

Ligand efficacy shifts a nuclear receptor conformational ensemble between transcriptionally active and repressive states

Nuclear receptors (NRs) are thought to dynamically alternate between transcriptionally active and repressive conformations, which are stabilized upon ligand binding. Most NR ligand series exhibit limited bias, primarily consisting of transcriptionally active agonists or neutral antagonists, but not repressive inverse agonists--a limitation that restricts understanding of the functional NR conformational ensemble. Here, we report a NR ligand series for peroxisome proliferator-activated receptor gamma (PPAR{gamma}) that spans a pharmacological spectrum from repression (inverse agonism) to activation (agonism) where subtle structural modifications switch compound activity. While crystal structures provide snapshots of the fully repressive state, NMR spectroscopy and conformation-activity relationship analysis reveals that compounds within the series shift the PPAR{gamma} conformational ensemble between transcriptionally active and repressive conformations that are populated in the apo/ligand-free ensemble. Our findings reveal a molecular framework for minimal chemical modifications that enhance PPAR{gamma} inverse agonism and elucidate their influence on the dynamic PPAR{gamma} conformational ensemble.

biophysics↗

bioRxiv2024

Alzheimer's disease-linked risk alleles elevate microglial cGAS-associated senescence and neurodegeneration in a tauopathy model

The strongest risk factors for Alzheimers disease (AD) include the {chi}4 allele of apolipoprotein E (APOE), the R47H variant of triggering receptor expressed on myeloid cells 2 (TREM2), and female sex. Here, we combine APOE4 and TREM2R47H (R47H) in female P301S tauopathy mice to identify the pathways activated when AD risk is the strongest, thereby highlighting disease-causing mechanisms. We find that the R47H variant induces neurodegeneration in female APOE4 mice without impacting hippocampal tau load. The combination of APOE4 and R47H amplified tauopathy-induced cell-autonomous microglial cGAS-STING signaling and type-I interferon response, and interferon signaling converged across glial cell types in the hippocampus. APOE4-R47H microglia displayed cGAS- and BAX-dependent upregulation of senescence, showing association between neurotoxic signatures and implicating mitochondrial permeabilization in pathogenesis. By uncovering pathways enhanced by the strongest AD risk factors, our study points to cGAS-STING signaling and associated microglial senescence as potential drivers of AD risk.

neuroscience↗

bioRxiv2023

Modulation of neural gene networks by estradiol in old rhesus macaque females.

The postmenopausal decrease in circulating estradiol (E2) levels has been shown to contribute to several adverse physiological and psychiatric effects. To elucidate the molecular effects of E2 on the brain, we examined differential gene expression and DNA methylation (DNAm) patterns in the nonhuman primate brain following ovariectomy (Ov) and subsequent E2 treatment. We identified several dysregulated molecular networks, including MAPK signaling and dopaminergic synapse response, that are associated with ovariectomy and shared across two different brain areas, the occipital cortex (OC) and prefrontal cortex (PFC). The finding that hypomethylation (p=1.6x10-51) and upregulation (p=3.8x10-3) of UBE2M across both brain regions, provide strong evidence for molecular differences in the brain induced by E2 depletion. Additionally, differential expression (p=1.9x10-4; interaction p=3.5x10-2) of LTBR in the PFC, provides further support for the role E2 plays in the brain, by demonstrating that the regulation of some genes that are altered by ovariectomy may also be modulated by Ov followed by hormone replacement therapy (HRT). These results present real opportunities to understand the specific biological mechanisms that are altered with depleted E2. Given E2s potential role in cognitive decline and neuroinflammation, our findings could lead to the discovery of novel therapeutics to slow cognitive decline. Together, this work represents a major step towards understanding molecular changes in the brain that are caused by ovariectomy and how E2 treatment may revert or protect against the negative neuro-related consequences caused by a depletion in estrogen as women approach menopause.

genetics↗

bioRxiv2023

CCT3 drives Sorafenib resistance by inhibiting TFRC-mediated iron uptake in HCC

Sorafenib is commonly utilized in the management of advanced hepatocellular carcinoma (HCC). However, its efficacy in extending patients survival is hindered by the development of drug resistance. By employing protein posttranslational modification (PTM) omics, including acetylome, phosphoproteome, and ubiquitinome, in conjunction with genome-wide CRISPR/Cas9 knockout library screening, we have successfully identified chaperonin containing TCP1 subunit 3 (CCT3) as a key factor contributing to Sorafenib resistance. Furthermore, we observed a reduction in the ubiquitination of CCT3 at lysine 21 (K21) subsequent to Sorafenib treatment. This study provides evidence that CCT3 hinders the recycling of transferrin receptor protein 1 (TFRC) by interacting with alpha-actinin-4 (ACTN4), which is influenced by K6-linked ubiquitination on K21. Depleting CCT3 increased the susceptibility of cells to Sorafenib-induced ferroptosis, while reintroducing CCT3 through transfection restored resistance to ferroptosis. Additionally, impairing ACTN4 or TFRC depletion compromised CCT3s ability to inhibit Sorafenib-induced ferroptosis. In summary, targeting CCT3 presents a potential strategy for overcoming Sorafenib resistance in HCC.

cancer biology↗

bioRxiv2023

INTEGRATED GLOBAL CHICKEN REFERENCE PANEL FROM 13,187 CHICKEN GENOMES

Chickens are a crucial source of protein for humans and a popular model animal for bird research. Despite the emergence of imputation as a reliable genotyping strategy for large populations, the lack of a high-quality chicken reference panel has hindered progress in chicken genome research. To address this issue, here we introduce the first phase of the 100 K Global Chicken Reference Panel Project (100 K GCRPP). The project includes 13,187 samples and provides services for varied applications on its website (http://farmrefpanel.com/GCRP/). Currently, two panels are available: a Comprehensive Mix Panel (CMP) for domestication diversity research and a Commercial Breed Panel (CBP) for breeding broilers specifically. Evaluation of genotype imputation quality showed that CMP had the highest imputation accuracy compared to imputation using existing chicken panel in animal SNPAtlas, whereas CBP performed stably in the imputation of commercial populations. Additionally, we found that genome-wide association studies using GCRP-imputed data, whether on simulated or real phenotypes, exhibited greater statistical power. In conclusion, our study indicates that the GCRP effectively fills the gap in high-quality reference panels for chickens, providing an effective imputation platform for future genetic and breeding research.

bioinformatics↗

bioRxiv2023

Deciphering fitness trade-offs in metabolite exchange at the origin of a bacterial cross-feeding community

Obligate cross-feeding is a common type of interaction among microbial communities, yet gaps persist in understanding its maintenance and limit practical applications. In particular, little is known about how contextualised metabolite exchange intensities affect community fitness, despite their influential role in shaping interdependencies1, diversities 2, and lifespan 3 of cross-feeding community members. Here I computationally test how amino acids isoleucine (ile) and lysine (lys) exchange intensities affect individual and community fitness of a two-strain auxotroph cross-feeding community. I innovatively integrated metabolite exchange intensities and multi-strain growth using Flux Balance Analysis (FBA) and evolutionary game theory, and showed that crossfeeding communities have the highest fitness when the metabolite exchange intensity is slightly above individual amino acid uptake demands, stimulated by cheaters presence. Using FBA with different metabolite uptake / secretion combinations, I discovered the individual amino acid demands are linearly correlated with sole carbon source (glucose) availability. Additionally, as cheating mutants emerge, costly exchange intensities can be better sustained when accumulated shared metabolites are accessible. This is the first study linking metabolite exchange intensities and cross-feeding community fitness considering all known metabolic reactions of a bacterial strain. The fittest metabolite exchange range and its relationships with glucose and shared metabolite availability shed lights on resilient microbial community engineering as well as metabolite exchange parameter constraints for multi-species population / metabolism models 4-6.

evolutionary biology↗