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Zheng, J.

Publications and source records attributed to Zheng, J..

At least 37 records · Page 2Linked to original sources

Accurate de novo design of peptides from programming biophysical landscape

Peptides regulate virtually every cellular process and emerge as transformative modalities in bioengineering and therapeutics. However, the de novo design of functional peptides remains challenging, as peptide-protein interactions are governed by delicate and dynamic biophysics that are difficult to model, and experimental datasets are scarce. Here we present NeoPep, a generative deep-learning framework that encodes biophysical principles to accurately design functional peptides de novo. By integrating over 5 million peptide-protein complexes spanning experimentally determined, sequence mimics, and structure ensembles, NeoPep learns the complex biophysical landscape governing peptide function and enables its programmable control. In prospective application across 10 diverse and challenging targets, NeoPep generated potent peptide binders, agonists, and antagonists with hit rates of 12.5-66.7%, even in the absence of defined binding sites or structure information. Beyond de novo co-design, NeoPep supports standalone structure or sequence redesign, readily discriminating subtle context differences. In the structure redesign mode, it generates highly selective peptides with atomic-level conformational accuracy (C RMSD < 2.0 [A] to our solved cryo-EM structure). This structural precision circumvents the need for experimental structure determination, further accelerating iterative sequence redesign to yield a 43.3-fold improvement in potency. These findings establish a general framework for translating biophysical principles into actionable peptide functions, with broad implications for basic research, bioengineering, and medicine.

molecular biology↗

Aortic valve stenosis promotes pathological shear stress-dependent epigenomic dysregulation in circulating T cells.

BackgroundCalcific aortic valve stenosis (AVS) is the most prevalent valvular heart disease in Western adults, yet no disease-modifying therapy exists. High shear stress (HSS) generated by progressive valvular obstruction drives endothelial injury and immune-mediated inflammation, but the contribution of circulating T cells to AVS pathogenesis remains poorly defined. ObjectivesWe tested whether chronic HSS corresponds with epigenomic reprogramming of peripheral T cells proportionate with hemodynamic severity to yield a clinically informative proxy of disease. MethodsA prospective cohort of 70 participants was recruited for peripheral blood sampling, including 34 with severe symptomatic AVS (aortic valve area <1.0 cm2, mean gradient [&ge;]40 mmHg) scheduled for transcatheter aortic valve implantation and 36 age- and sex-matched controls. Peripheral T cells were isolated and profiled by genome-wide CpG methylation (Illumina MethylationEPIC) and RNA-sequencing. To test whether HSS directly activates inflammatory signaling, Jurkat T cells were exposed to 20 dyn/cm2 HSS via parallel-plate microfluidic chamber and concomitant CD3/CD28 stimulation, followed by assessment of NFAT nuclear translocation and NFAT target gene expression. ResultsUnsupervised clustering of the 5,000 most-variable CpG loci resolved an epigenomic axis segregating AVS from control T cells (PC1, 15.8% variance explained; P = 3.9x10-6). Multivariable-adjusted analysis identified 3,950 differentially methylated positions (1,889 hyper-, 2,061 hypo-methylated), enriched in promoter-associated CpG islands implicating aortic valve morphogenesis (P = 6.0 x 10-10) and cell-cell adhesion pathways (P = 9.5 x 10-5). Multi-omics factor analysis isolated a latent factor that independently associated with AVS (adjusted P = 1.8x10-3; AUC = 0.79), enriched for chemokine receptor binding and TNF-family signaling, and correlated with canonical HSS-responsive transcripts, consistent with a T cell-mediated shear stress activation. An 18-CpG elastic-net methylation risk score discriminated AVS from controls (AUC = 0.89) and independently predicted hemodynamic severity ({beta} = 7.05 mmHg/SD, 95% CI 2.31-11.79). HSS augmented NFAT nuclear translocation in CD3/CD28-activated Jurkat T cells and induced NFAT-responsive inflammatory transcripts. ConclusionsSevere AVS is associated with promoter-enriched epigenomic remodeling of circulating T cells that converges on hemodynamic stress-dependent inflammatory programs. An 18-CpG methylation risk score outperforms clinical covariates and tracks hemodynamic severity, establishing peripheral T cell DNA methylation as a molecular corollary of AVS.

molecular biology↗

Mechanical organization yields degenerate dissipation beyond linear response

In non-equilibrium (active) systems, increased driving is commonly assumed to produce proportionally greater energy dissipation. Using picowatt-sensitive calorimetry, entropy-production analysis, rheology, and microscopy in reconstituted actomyosin networks, we show that this relationship breaks down as the material reorganizes under motor activity. Dissipation initially increases with myosin abundance but subsequently decreases despite continued network stiffening, indicating that energetic cost becomes regulated by the evolving mechanical state rather than actuator abundance alone. Comparing catch-bond (-actinin) and slip-bond (fascin) crosslinked networks reveals that bond mechanics shift the critical motor concentration at which this transition occurs, marking the onset of state-dependent energy conversion. Although these networks generate distinct active stresses and mechanical states, they can exhibit comparable dissipation rates, revealing that state-dependent energy conversion can produce degenerate dissipation, whereby mechanically distinct states exhibit similar energetic costs. These findings demonstrate that dissipation in active materials is governed not only by the magnitude of driving but also by the mechanical state that emerges in response to that driving, providing an experimental example of state-dependent energy conversion far from equilibrium.

biophysics↗

Learning latent conformational landscapes encoded in cryo-EM

A protein populates a landscape of structural states, abundant snapshots of which are sampled in every cryo-EM experiment. Current analysis averages these snapshots into single density maps or partitions them into discrete classes, discarding the continuous dynamics encoded in the data. Continuous latent-space methods offer a promising alternative, yet whether their learned representations are physically grounded remains unresolved. Here, we realize cryo-EM as structural landscape microscopy, in which latent density directly reflects the probabilistic distribution of molecular states. A central question is whether such a landscape reflects physical reality. For integrin v{beta}8, the learned landscape shows strong agreement with independently derived molecular dynamics simulations, supporting its physical plausibility. We then apply the landscape to structural states that conventional cryo-EM cannot resolve. For LIS1-mediated dynein activation, the landscape reveals a spectrum of states from dominant conformations to low-population intermediates defined by distinct binding modes, including a previously unresolved state. For the KCTD5/CUL3NTD/G{beta}{gamma} complex, the landscape resolves continuous conformational pathways directly from experimental data. Probability-guided particle selection further improves reconstruction quality.

molecular biology↗

Identification of SNARE Genes in Cucumber and the Role of CsSYP121 in Salt Stress Response

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are essential regulators of plant growth, development, and stress adaptation. In this study, we performed a comprehensive genome-wide identification of SNARE genes in cucumber (Cucumis sativus L.), uncovering 51 putative members designated as CsSNAREs. Phylogenetic analysis confirmed that these genes cluster into five major clades: Qa-CsSNARE (14), Qb-CsSNARE (9), Qc-CsSNARE (10), Qb+c-CsSNARE (3), and R-CsSNARE (15). Bioinformatic analysis of their promoter regions, coupled with expression profiling under diverse abiotic stress conditions, highlighted a heightened responsiveness within the Qa-CsSNARE subfamily. To validate this, we selected representative Qa-CsSNARE genes for quantitative real-time PCR analysis under drought and salt stress. Among these, CsSYP121 was notably induced by salt treatment. We subsequently generated transgenic cucumber lines overexpressing CsSYP121 and challenged them with salinity. Phenotypic assessment, combined with measurements of reactive oxygen species (ROS) accumulation and K+/Na+ ratios, demonstrated that CsSYP121 overexpression (OE) confers enhanced salt tolerance and boosts antioxidant capacity. We propose a model wherein CsSYP121 mitigates ROS-induced cellular damage under salt stress, potentially through promoting K+/Na+ homeostasis, thereby improving plant performance under saline conditions. Our findings identify CsSYP121 as a promising candidate gene for breeding salt-tolerant crops.

plant biology↗

Programming Biomolecular Interactions with All-Atom Generative Model

Biomolecular interactions lie at the core of cellular life, spanning diverse molecular modalities from small molecules to nucleic acids and proteins. Nevertheless, design strategies remain separated despite shared physicochemical principles of molecular recognition. Here we present AnewOmni, a unified generative framework trained on more than 5 million biomolecular complexes, that enables transferable molecular design across molecular scales by assembling chemically meaningful building blocks at atomic resolution. We further introduce programmable graph prompts to support user-defined chemical, topological, and geometric steering during generation, exploring hybrid and unconventional chemistries beyond canonical structures. We demonstrate that transferable learning of interaction patterns and physical constraints across molecular modalities is possible, via an atom-to-block latent space capturing both atomic details and structural priors. The framework successfully designed small molecules, peptides, and nanobodies targeting the challenging KRAS G12D switch II pocket, as well as orthosteric peptides and allosteric small-molecule inhibitors for PCSK9 in the absence of known binding site, achieving 23%-75% success with only low-throughput validation, bypassing modality-specific high-throughput screening. AnewOmni is the first to succeed in functional molecular design across all scales, from small chemical entities to large biologics, and represents a stepstone towards general molecular reasoning engines, advocating a generative foundation model for biomolecular interactions to enter regimes where data and human intuition remain limited.

bioengineering↗

A novel uN2CpolyG Transgenic Mouse Model Recapitulates Multisystemic polyG Proteinopathy Pathology of Neuronal Intranuclear Inclusion Disease

Neuronal intranuclear inclusion disease (NIID) is a polyglycine disease that primarily affects the neuronal and neuromuscular systems. Here, we developed a novel transgenic mouse model that faithfully recapitulates the multisystemic impairments associated with polyG intranuclear inclusions. Our findings demonstrate that polyG expression induces neurodegeneration, behavioral deficits, and age-dependent accumulation of uN2CpolyG aggregates across multiple tissues.

animal behavior and cognition↗

Neurons in the Human Substantia Nigra Respond to Cognitive Boundaries and Predict Memory

Segmenting mnemonic episodes from continuous experience is a key aspect of human episodic memory. The brain constantly forms predictions about what will happen next based on previous experience and knowledge, and prediction errors are thought to signal when a new event begins (cognitive boundaries). Dopamine has been closely linked to prediction error signals, yet it remains unknown how human midbrain neurons are modulated by cognitive boundaries and how their responses influence memory. To address these questions, we recorded activity of individual neurons in the human substantia nigra, a critical brain structure for dopamine production and regulation, while participants undergoing deep brain stimulation surgery watched a series of clips embedded with cognitive boundaries and performed a recognition memory task. We found that neural activity in the substantia nigra was robustly modulated by cognitive boundaries during clip viewing. Moreover, a subset of these boundary-responsive neurons also differentiated novel from familiar images during recognition, and their firing rates were indicative of participants memory success. These findings reveal that neurons in the human substantia nigra carry boundary- and novelty-related signals consistent with prediction error mechanisms that influence the encoding and retrieval of episodic memories.

neuroscience↗

Astrocyte-induced internal state transitions reshape brainwide sensory, integrative, and motor computations

Animals rapidly adapt to changing circumstances by shifting how they perceive, integrate, and act. Such flexibility is often attributed to transitions between internal states that exert widespread influence across the brain. Yet the mechanisms that drive state transitions and how they reconfigure brainwide computation remain unclear. Larval zebrafish, when actions are rendered futile by decoupling visual flow feedback from swimming in virtual reality, enter a temporary passive, energy-preserving state. In this state, astrocyte calcium levels are elevated, and swim reinitiation requires greater accumulated visual motion. Using whole-brain, cellular-resolution activity imaging, we observed widespread circuit alterations underlying this disengaged state: neuronal visual responses weakened, visual motion integration over time became dramatically leakier, motor inhibition increased, and motor preparation slowed, together suppressing conversion of sensory evidence into action. Astrocyte calcium rose during futile swimming, tracked the emergence and resolution of these brainwide changes, and was both necessary and sufficient to drive them. Thus, astrocytes orchestrate internal states that profoundly reshape neural computations, most powerfully at intermediate integrative processing stages, to meet changing demands. HighlightsO_LIInternal state change alters brainwide neuronal processing at every stage of the sensorimotor transformation C_LIO_LIEffects are most powerful at integrative stages through stimulus memory collapse C_LIO_LIAs state resolves, amplification of sensory representations synergizes with reduced motor inhibition for action reinitiation C_LIO_LIAstrocyte activity drives these brainwide adaptive shifts in neuronal dynamics C_LI

neuroscience↗

S-nitrosylation of the CLIP-protease, Persephone, Regulates Drosophila innate immunity

Nitric oxide (NO) modulates innate immunity, but its molecular targets in Drosophila melanogaster are largely undefined. A key mechanism of NO signalling is S-nitrosylation, the modification of cysteine thiols. The homeostasis of S-nitrosylation is maintained by S-nitrosoglutathione reductase (Gsnor), encoded by the fdh gene in D. melanogaster. As reduced Gsnor activity enhances pathogen sensitivity in plants, we investigated its role in D. melanogaster. Here, we show that flies lacking fdh exhibit increased susceptibility to the fungus Beauveria bassiana and the bacterium Staphylococcus aureus, pathogens combatted by the Toll pathway. This immune deficiency correlates with impaired Toll-dependent antimicrobial peptide expression. We demonstrate that the Toll pathway protease Persephone (Psh) is S-nitrosylated in vivo and that loss of Gsnor prevents its proteolytic activation following infection. We propose a model where Gsnor-mediated regulation of NO is essential for Toll activation, preventing excessive S-nitrosylation of Psh and ensuring a robust immune response.

molecular biology↗

lncRNAs contribute to caste differentiation as a regulatory layer in ants

Caste differentiation in ants represents one of the major evolutionary transitions and provides a unique model for studying developmental mechanisms underlying division of labor. Genetically identical individuals follow divergent epigenetically-regulated developmental trajectories that give rise to morphologically distinct phenotypes and specialized roles. While long non-coding RNAs (lncRNAs) are emerging as key epigenetic regulators across diverse biological systems, their specific contributions to caste development in social insects remain largely unexplored. Here, we conducted comprehensive transcriptomic analyses across major developmental stages of two evolutionarily and ecologically distinct ants Monomorium pharaonis and Acromyrmex echinatior, identifying over 10,000 lncRNAs. We demonstrated that lncRNAs exhibit dynamic, caste-specific expression patterns throughout development. We also identified a subset of lncRNAs displaying canalized expression patterns, characterized by progressively increasing caste bias and decreasing within-caste variation as development proceeds. Co-expression analyses revealed that canalized lncRNAs are functionally linked to canalized protein-coding genes, which are crucial regulators for caste differentiation. These canalized lncRNAs show striking tissue-specific enrichment consistent with canalized protein-coding genes. Functional validation through RNA interference revealed that canalized lncRNAs directly regulate caste-specific traits. Furthermore, juvenile hormone treatment capable of redirecting worker lncRNA expression profiles toward gyne-like patterns, with similar expression changes and tissue specificity to JH-responsive protein-coding genes, linking lncRNA regulation to established hormonal pathways controlling caste fate. Our findings establish lncRNAs as active architects of caste differentiation in social insects, demonstrating that these rapidly-evolving regulatory molecules contribute to the evolution and maintenance of social phenotypes through tissue-specific regulation of caste-associated developmental programs.

developmental biology↗

A gastric microbial chromatin remodeler drives gastric cancer progression and immune evasion by reprogramming the host epigenome

Emerging evidence highlights the crucial role of microbial communities in modulating cancer development and progression. In gastric cancer (GC), we identify Streptococcus anginosus (SA) as a tumor-resident oncobacterium that drives both tumor progression and immune evasion. We define a novel mechanism in which SA secretes extracellular vesicles (saEVs) that translocate the bacterial chromatin remodeler saSNF2 into host cell. There, saSNF2 partners with host transcription factor TEAD1--through its ATPase activity and participation in BAF complex assembly--to coordinately activate oncogenic transcription. This transkingdom interaction upregulates the palmitoyltransferase ZDHHC11, which in turn stabilizes PD-L1 via palmitoylation to establish an immunosuppressive niche, while also amplifying other TEAD1 target genes to fuel tumor progression. Functionally, saEVs promote tumor growth and limit CD8+ T-cell infiltration in vivo. Strikingly, pharmacological inhibition of ZDHHC11 reverses immune evasion and synergizes with anti-PD-1 checkpoint blockade. Our results establish SA as a multifaceted driver of GC and reveal the saSNF2-ZDHHC11 axis as a promising target to potentiate immunotherapy.

cancer biology↗

6mA demethylase Mi-NMAD-1 modulates nematode development and parasitism through the transcription factor Mi-nhr-118

N6-methyladenine (6mA) DNA methylation has emerged as an important epigenetic mark in eukaryotes, but its biological role in plant-parasitic nematodes remains largely unexplored. Here, we demonstrate that 6mA methylation is essential for the embryonic development and parasitic ability of Meloidogyne incognita. Silencing of the 6mA demethylase genes minmad-1 significantly reduced egg hatching, revealing that 6mA-mediated regulation is required for nematode development. Transcriptome analyses showed that minmad-1 knockdown downregulated genes involved in embryogenesis, RNA biosynthesis, and cell differentiation, suggesting a critical role of 6mA in developmental gene regulation. Among the transcription factors affected by minmad-1 silencing, Mi-nhr-118, a nuclear hormone receptor orthologous to C. elegans nhr-118, was identified as a key regulator of embryonic development. Functional assays confirmed that RNAi or host-induced gene silencing (HIGS) of Mi-nhr-118 led to developmental arrest, reduced gall and egg mass formation, and impaired infectivity across multiple Meloidogyne species. ChIP-seq analysis revealed that Mi-nhr-118 directly binds to promoters of genes associated with cellular regulation and developmental signaling. Several downstream targets, including transcription factors (Mi_23621.1, Mi_39647.1) and genes implicated in metabolic and signaling processes (Mi_03067.1, Mi_08398.1), were shown to be essential for both embryogenesis and parasitism. Functional enrichment analyses of Mi-nhr-118 target genes indicated suppression of immune-related signaling, carbohydrate recognition, and glycoprotein biosynthetic pathways following gene silencing. Collectively, these findings establish Mi-nhr-118 as a central regulator linking 6mA-mediated epigenetic control to development and parasitism in M. incognita.

molecular biology↗

Satellite microglia gate neuronal excitability by shielding inhibitory synapses in adult brain

Microglia, the primary immune cells of the central nervous system, are known for sculpting excitatory neural circuits via dynamic processes. However, their role in modulating inhibitory synaptic connections in adulthood remains largely unexplored. In this study, we identified an underappreciated microglia subpopulation, satellite microglia with physical soma-soma contact with neurons, that reshape inhibitory circuit connectivity and gate neuronal activity by shielding inhibitory synapses in the adult mouse brain. Using chronic in vivo two-photon imaging in adult mice, we observed in real time that satellite microglia associations displaced perisomatic inhibitory synapses whereas their dissociation permitted inhibitory synaptogenesis. Redistribution of satellite microglia reorganized inhibitory connectivity, altered local neural networks and changed behaviors. These findings establish satellite microglia as key architects of inhibitory circuitry and suggest their broader role in neural plasticity in health and disease.

neuroscience↗

ERAD Activity Distinguishes the Functional Heterogeneity of Hematopoietic Stem Cells

Hematopoietic stem cells (HSCs) rely on precisely controlled proteostasis to sustain lifelong self-renewal, yet whether intrinsic proteostatic characteristics can prospectively define functional diversity within the HSC pool remains unknown. In this study, we developed a dual-fluorescence reporter system to visualize endoplasmic reticulum-associated degradation (ERAD) activity in vivo and discovered that ERAD activity can prospectively predicts the long-term reconstitution potential of HSCs. Remarkably, ERAD states were maintained through self-renewal, revealing an inheritable "proteostatic memory" within the HSC pool. Transcriptomic and functional analyses identified SOCS2 as a key regulator of this process: SOCS2 inhibits JAK2 signaling to sustain ERAD activity, whereas hyperactive JAK2 interacts with the ERAD E3 ligase Hrd1 and suppresses VCP-mediated misfolded substrate. These findings define a SOCS2-JAK2-ERAD axis that connects cytokine signaling to intrinsic proteostasis remodeling, establishing ERAD activity as a predictive and heritable marker of HSC function and providing a conceptual framework for understanding hematopoietic stem cell heterogeneity.

cell biology↗

Evaluate and simulate the reproduction and survival of a reintroduced population in an endangered bird species Crested ibis (Nipponia nippon)

O_LIReintroduction programs are critical for restoring endangered species. However, scientific assessments and management recommendations based on comprehensive vital rates across the entire life cycle remain limited for such programs. The Crested ibis (Nipponia nippon), once nearly extinct, has been the focus of intensive conservation efforts, including reintroduction into its historical range. Here, we systematically evaluate the success of a Crested ibis reintroduction population by integrating long-term field monitoring with population dynamic modeling. C_LIO_LIWe conducted a systematic, multi-year (2023-2025) demographic study of a reintroduced Crested ibis population in Dongzhai National Nature Reserve, China. From 2013 to 2023, a total of 133 captive Crested ibises were released in seven batches within the nature reserve. By 2025, the wild population had exceeded 500. Based on the combination of field monitoring (n = 176 pairs) and GPS telemetry (n = 74 GPS tags, the longest monitoring time lasting 4 years), we quantified reproductive output and mortality rates across six life stages: nest building, incubation, offspring provisioning, fledgling (< 1 year), sub-adult (1-2 years), and adult (> 2 years). C_LIO_LIThe results show that the average clutch size of this population is 3.24 {+/-} 0.08, and each pair of parent birds can rear 1.31 {+/-} 0.12 nestlings to fledging each year. We found that high mortality during the incubation (32.5%, n = 425 eggs), offspring provisioning (34.1%, n = 287 chicks), and fledgling stages (38.6%, n = 63 birds). Key causes included unfertilized eggs, predation, starvation, and human disturbance. On the other hand, the mortalities in the nest building (9.1%, n = 176 pairs), sub-adult (9.8%, n = 28 birds) and adult stage (21.3%, n = 15 birds) were relatively low. Stage-structured matrix model shows a positive population growth of this reintroduced population (growth rate {lambda} = 1.053), with the population expected to increase 13-fold over 50 years (6,858 individuals). Sensitivity analysis indicates that adult survival had the strongest influence on population growth. Correspondingly, we predict that by 2075, its distribution range will expand 13-fold in tandem with population growth, exceeding 51,000 km{superscript 2} and covering several surrounding cities. C_LIO_LIOur comprehensive monitoring, evaluation, and simulation across the full life-cycle confirm that the reintroduced population is successfully established and self-sustaining. This finding addresses a critical research gap: the lack of a scientific and systematic framework for assessing population reintroductions in endangered species. Furthermore, we identified key conservation practices to enhance population growth and stability, including predator control, supplemental feeding, the rescue of weak chicks, and reducing human disturbance through public engagement. To ensure long-term viability, we also recommend implementing genetic management to avoid inbreeding. The resulting framework provides a practical model for improving reintroduction success and promoting species recovery in other endangered species. C_LI

ecology↗

A SARS-CoV-2 entry inhibitor trimerizes to lock the spike protein in a closed conformation

The SARS-CoV-2 spike protein binds its receptor ACE2 to initiate target-cell infection. To engage ACE2, at least one of the three receptor-binding domains (RBDs) of the spike must adopt the up orientation. Here we describe S22, a potent, bioavailable, and non-toxic inhibitor of BA.2 and all subsequent Omicron variants. Cryo-EM analyses showed that S22 assembled as a trimer in a previously uncharacterized pocket of the spike apex, stabilizing all three RBDs in the down orientation, thereby preventing ACE2 association. Binding studies, especially those using mixed S22-sensitive and -resistant spikes, imply a cooperative assembly of three S22 molecules with three RBDs, resulting in an unusually slow S22 off-rate. Consistent with its slow dissociation and favorable pharmacokinetics, S22 suppressed viral replication 100-fold in the lungs of XBB.1.5-infected mice. Thus, S22 potently inhibits Omicron entry through a distinct mechanism whereby a small compound assembles cooperatively as a trimer to stabilize spike in an inactive conformation.

microbiology↗

Flexible parental care in a songbird correlates with sex-specific responses to seasonal phenology, mating opportunity and reproductive success

O_LISpecies with diverse parental care patterns often exhibit flexibility in response to environmental changes. Such changes can influence parental care decisions by altering the trade-offs between current and future reproduction. While previous studies have revealed correlations between specific social and ecological factors and parental care patterns, the joint effects of multiple factors could be rather complex and may result in different outcomes within and across populations, and between sexes. C_LIO_LIIn this study, we revealed parental care systems and their seasonal variations across three geographic populations in a polygamous species, the Chinese penduline tits (Remiz consobrinus), by monitoring breeding events over years. To investigate how local conditions (including social and ecological conditions) correlate with sex-specific parental care patterns, we compared breeding phenology and local conditions (including season length, mating opportunity and reproductive success) across the populations. C_LIO_LIStriking population differences in parental care strategies are found in this species: biparental care predominated in one population, whereas female-only care was more common in the other two. Our analyses reveal that, despite a large difference in season length, the time of egg-laying peaked similarly across the three populations. Female penduline tits determined the breeding phenology, which varies male mating opportunities dramatically over the season. For all populations, male Chinese penduline tits were more likely to desert the clutch when male mating opportunities were high. In contrast, females consistently provided care, regardless of variation in female mating opportunities. C_LIO_LIWe also found that fitness costs on the current brood resulting from offspring desertion differed across populations. This desertion cost on brood fitness matters more than achieving a high reproductive reward in driving the emergence of uniparental care, contrary to the theory that uniparental care only occurs when single parents can efficiently raise nestlings alone. C_LIO_LIOur study demonstrates that similar parental care patterns across populations could result from different underlying factor interactions and highlights the consistent sex-specific responses to local conditions in parental care. C_LI

ecology↗