Biology subjects

Dong, H.

Publications and source records attributed to Dong, H..

At least 91 records · Page 5Linked to original sources

bioRxiv2023

Plant diversity stabilizes soil temperature

Extreme weather events are occurring more frequently, and research has shown that plant diversity can help mitigate impacts of climate change by increasing plant productivity and ecosystem stability1,2. Although soil temperature and its stability are key determinants of essential ecosystem processes related to water and nutrient uptake3 as well as soil respiration and microbial activity4, no study has yet investigated whether plant diversity can buffer soil temperature fluctuations. Using 18 years of a continuous dataset with a resolution of 1 minute ([~]795,312,000 individual measurements) from a large-scale grassland biodiversity experiment, we show that plant diversity buffers soil temperature throughout the year. Plant diversity helped to prevent soil heating in hot weather, and cooling in cold weather. Moreover, this effect of plant diversity increased over the 18-year observation period with the aging of experimental communities and was even stronger under extreme conditions, i.e., on hot days or in dry years. Using structural equation modelling, we found that plant diversity stabilized soil temperature by increasing soil organic carbon concentrations and, to a lesser extent, by increasing the plant leaf area index. We suggest that the diversity-induced stabilization of soil temperature may help to mitigate the negative effects of extreme climatic events such as soil carbon release, thus slow global warming.

ecology↗

bioRxiv2023

Label-free quantitative proteomics analyses of mouse astrocytes provides insight into the host response mechanism at different developmental stages of Toxoplasma gondii

Toxoplasma gondii (T. gondii) is an opportunistic parasite that can infect the central nervous system (CNS), causing severe toxoplasmosis and behavioral cognitive impairment. Mortality is high in immunocompromised individuals with toxoplasmosis, most commonly due to reactivation of infection in the CNS. There are still no effective vaccines and drugs for the prevention and treatment of toxoplasmosis. There are five developmental stages for T. gondii to complete life cycle, of which the tachyzoite and bradyzoite stages are the key to the acute and chronic infection. In this study, to better understanding of how T. gondii interacts with the host CNS at different stages of infection, we constructed acute and chronic infection models of T. gondii in astrocytes, and used label-free proteomics to detect the proteome changes before and after infection, respectively. A total of 4676 proteins were identified, among which 163 differentially expressed proteins (DEPs) (fold change[≥]1.5 or [≤]0.67 and p-value[≤]0.05) including 109 up-regulated proteins and 54 down-regulated proteins in C8-TA vs C8 group, and 719 DEPs including 495 up-regulated proteins and 224 down-regulated proteins in C8-BR vs C8-TA group. After T. gondii tachyzoites infected astrocytes, DEPs were enriched in immune-related biological processes to promote the formation of bradyzoites and maintain the balance of T. gondii, CNS and brain. After T. gondii bradyzoites infected astrocytes, the DEPs up-regulated the hosts glucose metabolism, and some up-regulated DEPs were closely related to neurodegenerative diseases. These findings not only provide new insights into the psychiatric pathogenesis of T. gondii, but also provide potential targets for the treatment of acute and chronic Toxoplasmosis.

microbiology↗

bioRxiv2023

Benchmarking Algorithms for Gene Set Scoring of Single-cell ATAC-seq Data

Gene set scoring (GSS) has been routinely conducted for gene expression analysis of bulk or single-cell RNA-seq data, which helps to decipher single-cell heterogeneity and cell-type-specific variability by incorporating prior knowledge from functional gene sets. Single-cell assay for transposase accessible chromatin using sequencing (scATAC-seq) is a powerful technique for interrogating single-cell chromatin-based gene regulation, and genes or gene sets with dynamic regulatory potentials can be regarded as cell-type specific markers as if in scRNA-seq. However, there are few GSS tools specifically designed for scATAC-seq, and the applicability and performance of RNA-seq GSS tools on scATAC-seq data remain to be investigated. We systematically benchmarked ten GSS tools, including four bulk RNA-seq tools, five single-cell RNA-seq (scRNA-seq) tools, and one scATAC-seq method. First, using matched scATAC-seq and scRNA-seq datasets, we find that the performance of GSS tools on scATAC-seq data is comparable to that on scRNA-seq, suggesting their applicability to scATAC-seq. Then the performance of different GSS tools were extensively evaluated using up to ten scATAC-seq datasets. Moreover, we evaluated the impact of gene activity conversion, dropout imputation, and gene set collections on the results of GSS. Results show that dropout imputation can significantly promote the performance of almost all GSS tools, while the impact of gene activity conversion methods or gene set collections on GSS performance is more GSS tool or dataset dependent. Finally, we provided practical guidelines for choosing appropriate pre-processing methods and GSS tools in different scenarios.

bioinformatics↗

bioRxiv2022

The necessity of considering enzymes as compartments in constraint-based genomescale metabolic models

As the most widespread and practical digital representations of living cells, metabolic network models have become increasingly precise and accurate. By integrating cellular resources and abiotic constraints, the prediction functions were significantly expanded in recent years. However, we found that if unreasonable modeling methods were adopted due to the lack of consideration of biological knowledge, the conflicts between stoichiometric and other constraints, such as thermodynamic feasibility and enzyme resource availability, would lead to distorted predictions. In this work, we investigated a prediction anomaly of EcoETM, a constraints-based metabolic network model, and introduced the idea of enzyme compartmentalization into the analysis process. Through rational combination of reactions, we avoid the false prediction of pathway feasibility caused by the unrealistic assumption of free intermediate metabolites. This allowed us to correct the pathway structures of L-serine and L-tryptophan. Specific analysis explains the application method of EcoETM-like model, demonstrating its potential and value in correcting the prediction results in pathway structure by resolving the conflict between different constraints and incorporating the evolved roles of enzymes as reaction compartments. Notably, this work also reveals the trade-off between product yield and thermodynamic feasibility. Finally, we provide a preliminary comparison of the thermodynamic feasibility of ammonia and glutamine as amino donors, which revealed that the direct utilization of ammonia does not have a decisive impact on the thermodynamic feasibility of the anthranilate pathway. Our work is of great value for the structural improvement of constraints-based models.

bioinformatics↗

bioRxiv2022

Resilient CD8+ T cells maintain a high cytotoxic capacity by balancing ROS via ME1 upregulation

Cytotoxic T lymphocytes (CTL) are indispensable in anti-tumor immunity. Although CTLs are prone to exhaustion in patients with advanced cancer, T cell resiliency explains the presence of tumor-reactive CTLs that are less exhausted, capable of cytolytic function, expansion, and rebound in response to immunotherapy to reject metastatic malignances. However, the features of resilient T cells have not been clearly defined. In this report, we demonstrate that peripheral CX3CR1+ CD8+ T cells with low mitochondrial membrane potential rebounded CTL function quickly after radiation therapy in patients with large tumor burden portraying their functional resiliency. Furthermore, CX3CR1+ CD8+ T cell with low, but not high, mitochondrial membrane potential are highly cytotoxic, accumulate less reactive oxygen species (ROS), and express more Malic enzyme 1 (ME1). ME1 overexpression increases ATP production in a glycolysisindependent manner while concurrently curtailing excessive ROS in activated CD8+ T cells; and expands CX3CR1+NKG7+ effector CD8+ T cells with enhanced cytotoxicity. Importantly, transfection of ME1 mRNA promotes tumoricidal activity in CD8+ T cells from patients with advanced cancers. Our study reveals a mechanism used by CTLs to balance excessive ROS via ME1 to maintain a metabolic and functional resiliency. Modification of ME1 expression in CTLs may be a novel method to improve the efficacy of cancer immunotherapy by preventing T cell exhaustion. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=191 SRC="FIGDIR/small/517988v3_ufig1.gif" ALT="Figure 1"> View larger version (64K): org.highwire.dtl.DTLVardef@12e0f36org.highwire.dtl.DTLVardef@e8d412org.highwire.dtl.DTLVardef@1baf57eorg.highwire.dtl.DTLVardef@14b2b43_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LICX3CR1+ and low Dy m identify functional resilient CD8+ T cells. C_LIO_LIResilient CD8+ T cells are highly cytotoxic and have less ROS. C_LIO_LIResilient CD8+ T cells express more ME1 that can balance extra ROS. C_LIO_LIME1 overexpression can promote CTL function of CD8+ T cells. C_LI

immunology↗

bioRxiv2022

Microglial process dynamics enhance neuronal activity by shielding GABAergic synaptic inputs

Microglia are resident immune cells of the central nervous system (CNS) and play key roles in brain homeostasis. During anesthesia, microglia increase their dynamic process surveillance and interact more closely with neurons. However, the functional significance of microglial process dynamics and neuronal interaction has remained unclear. Using in vivo two-photon imaging in awake mice, we discover that microglia enhance neuronal activity after the cessation of general anesthesia. Hyperactive neuron somata are directly contacted by microglial processes, which specifically co-localize with GABAergic boutons. Electron microscopy-based synaptic reconstruction after two-photon imaging reveals that microglial processes enter into the synaptic cleft to shield GABAergic inputs. Microglial ablation or loss of microglial {beta}2-adrenergic receptors prevent post-anesthesia neuronal hyperactivity. Together, our study demonstrates a previously unappreciated function of microglial process dynamics, which allow microglia to transiently boost neuronal activity by physically shielding inhibitory inputs.

neuroscience↗

bioRxiv2022

A new polymodal gating model of the proton-activated chloride channel

The proton-activated chloride (PAC) channel plays critical roles in ischemic neuron death, but its activation mechanisms remain elusive. Here, we interrogated PAC channel gating using its unique bidirectional modulator C77304 as a pharmacological probe. C77304 activated the PAC channel by acting on its proton gating, while simultaneously inhibiting channel activity at higher doses, through interaction with two modulatory sites with different affinities and state-dependence. Excitingly, we revealed that PAC undergoes intrinsic proton gating-independent voltage activation, which was defined by an ion-flux gating mechanism. Scanning-mutagenesis and molecular dynamics simulation confirmed that E181, E257, and E261 in human PAC form the primary proton sensors, as alanine mutations eliminated the channels proton gating while sparing the voltage-dependent gating. This proton sensing mechanism was basically conserved among orthologous PAC channels. Collectively, our data unveils the polymodal gating and proton sensing mechanisms in the PAC channel which may inspire potential drug development.

neuroscience↗

bioRxiv2022

Effect of Nonlinear Hyperelastic Property of Arterial Tissues on the Pulse Wave Velocity based on the Unified-Fiber-Distribution (UFD) Model

Pulse wave velocity (PWV) is a key, independent risk factor for future cardiovascular events. The Moens-Korteweg equation describes the relation between PWV and the stiffness of arterial tissue with an assumption of isotopic linear elastic property of the arterial wall. However, the arterial tissue exhibits highly nonlinear and anisotropic mechanical behaviors. There is a limited study regarding the effect of arterial nonlinear and anisotropic properties on the PWV. In this study, we investigated the impact of the arterial nonlinear hyperelastic properties on the PWV, based on our recently developed unified-fiber-distribution (UFD) model. The UFD model considers the fibers (embedded in the matrix of the tissue) as a unified distribution, which expects to be more physically consistent with the real fiber distribution than existing models that separate the fiber distribution into two/several fiber families. With the UFD model, we fitted the measured relation between the PWV and blood pressure which obtained a good accuracy. We also modeled the aging effect on the PWV based on observations that the stiffening of arterial tissue increases with aging, and the results agree well with experimental data. In addition, we did parameter studies on the dependence of the PWV on the arterial properties of fiber initial stiffness, fiber distribution, and matrix stiffness. The results indicate the PWV increases with increasing overall fiber component in the circumferential direction. The dependences of the PWV on the fiber initial stiffness, and matrix stiffness are not monotonic and change with different blood pressure. The results of this study could provide new insights into arterial property changes and disease information from the clinical measured PWV data.

bioengineering↗

bioRxiv2022

Discovery of a novel monoclonal PD-L1 antibody H1A that promotes T-cell mediated tumor killing activity in renal cell carcinoma

In the last decade, the therapeutic landscape of renal cell carcinoma has rapidly evolved with the addition of PD-1/PD-L1 immune checkpoint inhibitors in the armamentarium of oncologists. Despite clinical evidence of improved oncological outcomes, only a minority of patients experience long-lasting antitumor immune response and complete response. The intrinsic and acquired resistance to PD-1/PD-L1 immune checkpoint blockade is an important challenge for patients and clinicians as no reliable tool has been developed to predict individualized response to immunotherapy. In this study, we demonstrate the translational relevance of an ex-vivo functional assay that measure the tumor cell killing ability of patient-derived CD8 T cells isolated from peripheral blood. Cytotoxic activity of CD8 T cells was improved at 3-month post-radical nephrectomy compared to baseline and it was associated with higher circulating levels of tumor-reactive effector CD8 T cells (CD11ahighCX3CR1+GZMB+). Pretreatment of peripheral immune cells with FDA-approved PD-1/PD-L1 inhibitors enhanced tumor cell killing activity of CD8 T cells but differential response was observed at the individual patient level. Finally, we found a newly developed monoclonal antibody (H1A), which induces PD-L1 degradation, demonstrated superior efficacy in promoting T-cell mediated tumor killing activity compared to FDA-approved PD-1/PD-L1 inhibitors. PBMC immunophenotyping by mass cytometry revealed enrichment of effector CD8 T cells in H1A-treated PBMC. To conclude, our study lays the ground for future investigation of the therapeutic value of H1A as a next-generation immune checkpoint inhibitor. Furthermore, further work is needed to evaluate the potential of measuring T-cell cytotoxicity activity as a tool to predict individual response to immune checkpoint inhibitors in patients with advanced renal cell carcinoma.

immunology↗

bioRxiv2022

Genetically encoded sensors for measuring histamine release both in vitro and in vivo

Histamine (HA) is a key biogenic monoamine involved in a wide range of physiological and pathological processes in both the central nervous system and the periphery. Because the ability to directly measure extracellular HA in real-time will provide important insights into the functional role of HA in complex circuits under a variety of conditions, we developed a series of genetically encoded G protein-coupled receptor activation-based (GRAB) HA (GRABHA) sensors. These sensors produce a robust increase in fluorescence upon HA application, with good photostability, sub-second kinetics, nanomolar affinity, and high specificity. Using these GRABHA sensors, we measured electrical stimulation-evoked HA release in acute brain slices with high spatiotemporal resolution. Moreover, we recorded HA release in the preoptic area of the hypothalamus and in the medial prefrontal cortex during the sleep-wake cycle in freely moving mice, finding distinct patterns of HA release in these specific brain regions. Together, these in vitro and in vivo results show that our GRABHA sensors have high sensitivity and specificity for measuring extracellular HA, thus providing a robust new set of tools for examining the role of HA signaling in both health and disease.

neuroscience↗

bioRxiv2022

Macrophage migrates on alternate non-adhesive surfaces

Macrophages migrate across tissues upon immune demand, but their motility on heterogeneous substrates remains unclear. Protein-repelling reagents, e.g., poly(ethylene) glycol (PEG), are routinely employed to resist cell adhering and migrating. Contrary to this perception, we discovered a unique locomotion of macrophages in vitro that they overcome non-adhesive PEG gaps to reach adhesive regions in a mesenchymal mode. Adhesion to adhesive regions was a prerequisite for macrophages to perform further locomotion on the PEG regions, or else they kept a suspended round shape. Podosomes were found highly enriched on the PEG region, which supported macrophage migration. Myosin IIA played a negative role in macrophage motility. Moreover, a developed cellular Potts model reproduced the experimental observations. These findings uncovered a new migratory behavior on non-adhesive surfaces in macrophages. One-Sentence SummaryMacrophages can migrate across non-adhesive surfaces that are absolute boundaries for other cell types.

cell biology↗

bioRxiv2022

Human Brain Development: a cross-sectional and longitudinal study integrating multiple neuromorphological features

Brain maturation studies typically examine relationships linking a single morphometric feature with aspects of cognition, behavior, age, or other demographic characteristics. However, the coordinated spatiotemporal arrangement of morphological features across development and their associations with behavior are unclear. Here, we examine covariation across multiple cortical features (cortical thickness [CT], surface area [SA], local gyrification index [GI], and mean curvature [MC]) using magnetic resonance images from the long-running National Institute of Mental Health developmental cohort (ages 5-25). Neuroanatomical covariance was examined using non-negative matrix factorization (NMF), which decomposes covariance resulting in a parts-based representation. Cross-sectionally, we identified six components of covariation which demonstrate differential contributions of CT, GI, and SA in hetero- vs. unimodal areas. We sought to use this technique longitudinally to examine covariance in rates of change, which highlighted a preserved SA in unimodal areas and changes in CT and GI in heteromodal areas. Using behavioral partial least squares (PLS), we identified a single latent variable (LV; 96 % covariance explained) that recapitulated patterns of reduced CT, GI, and SA that are generally related to older age, with limited contributions of IQ and SES. Longitudinally, PLS revealed three LVs that demonstrated a nuanced developmental pattern that highlighted a higher rate of maturational change in SA and CT in higher IQ and SES females. This novel characterization of brain maturation provides an important understanding of the interdependencies between morphological measures, their coordinated development, and their relationship to biological sex, cognitive ability, and the resources of the local environment. SignificanceThe complex anatomy of the cortical sheet is best characterized using multiple morphometric characteristics. We expanded on recent developments in matrix factorization to identify spatial patterns of covariance across the cortical sheet. Using a large, well-characterized dataset, we examined the differential contributions of neuroanatomical features to cortical covariation in a single analytical framework using both cross-sectional and longitudinal data. We identified dominant modes of covariance between cortical morphometric features and their coordinated pattern of change, demonstrating sexually differentiated patterns and a strong association with variability in age, socioeconomic status, and cognitive ability. This novel characterization of cortical morphometry provides an important understanding of the interdependencies between neuroanatomical measures in the brain and behavioral development context.

neuroscience↗

bioRxiv2022

Potent Bacterial Vaccines Require FcγRIIB-mediated Pathogen Capture by Liver Sinusoidal Endothelium

Certain vaccines are more effective than others against microbial infections, but the molecular mechanisms separating the two types of vaccines are largely undefined. Here, by comparing two vaccines of Streptococcus pneumoniae with identical antigens but different efficacies (pneumococcal conjugate vaccine - PCV13 and pneumococcal polysaccharide vaccine - PPV23), we reveal that superior vaccine protection against blood-borne bacteria is primarily achieved by activating pathogen capture of the sinusoidal endothelial cells (ECs) in the liver. Consistent with its superior protection in humans, PCV13 confers a more potent protection than PPV23 against pneumococcal infection in mice. In vivo real-time imaging and genetic mutagenesis revealed that PCV13 activates both liver ECs and resident macrophages Kupffer cells (KCs) to capture IgG-coated bacteria via IgG Fc gamma receptor (Fc{gamma}R). In particular, the Fc{gamma}RIIB-mediated capture by ECs is responsible for PCV13-induced superior protection. In contrast, PPV23 only activates KCs (but not ECs) to achieve a less effective pathogen capture and protection through complement receptor-mediated recognition of IgM- and C3-coated bacteria. These liver-based vaccine protection mechanisms are also found with the vaccines of Neisseria meningitidis and Klebsiella pneumoniae, another two important invasive human pathogens. Our findings have uncovered a novel EC- and Fc{gamma}RIIB-mediated mechanism in the liver for more efficacious vaccine protection. These findings can serve as in vivo functional readouts to evaluate vaccine efficacy and guide the future vaccine development. One Sentence SummaryVaccine efficacy is defined by Fc{gamma}RIIB-mediated capture of antibody-coated bacteria via liver sinusoidal endothelial cells.

immunology↗

bioRxiv2022

The integrated LIM-peptidase domain of the CSA1/CHS3 paired immune receptor detects changes in DA1 family peptidase inhibitors to confer Albugo candida resistance in Arabidopsis.

White blister rust, caused by the oomycete Albugo candida, is a widespread disease of Brassica crops. The Arabidopsis CSA1/DAR4 (also known as CSA1/CHS3) paired immune receptor carries an Integrated Domain (ID) with homology to the DA1 family of peptidases. Using domain swaps with DA1 family members, we show that the DAR4 ID acts as an integrated decoy for DAR3, which interacts with and inhibits the peptidase activities of DA1, DAR1 and DAR2 family members. Albugo infection rapidly lowered DAR3 levels and activates DA1 peptidase activity. This promotes endoreduplication of host tissues to support pathogen growth. We propose that DAR4/CSA1 senses the actions of a putative Albugo effector that reduces DAR3 levels and initiates defense.

plant biology↗

bioRxiv2022

Single cell RNA sequencing reveals mechanisms underlying a senescence-like phenotype of Alveolar Macrophages during Aging

Alveolar Macrophages (AMs) are unique innate immune cells that reside in the alveolar space and accommodate the ever-changing needs of the lungs against internal and external challenges. During homeostasis, AMs maintain themselves through self-renewal without input from adult hematopoietic stem cells. Currently, little is known regarding the influence of aging on AM dynamics, heterogeneity and transcriptional profiles. Here, we identified CBF{beta} as an indispensable transcription factor that ensures AM self-renewal. Deficiency in CBF{beta} led to decreased proliferation and self-renewal ability of AMs. Moreover, with single cell RNA sequencing analysis of AMs from young and aged mice, we discovered that despite similarities in the transcriptome of proliferating cells, AMs from the aged mice exhibited reduced embryotic stem cell-like features. Aged AMs also showed diminished capacity for DNA repair, potentially contributing to impaired cell cycle progression and elevation of senescence markers. In accordance with the analysis, we observed reduced number of AMs in aged mice, which had defective self-renewal ability and were more sensitive to the reduction of GM-CSF. Interestingly, decreased CBF{beta} was observed in the cytosol of AMs from aged mice. A similar senescence-like phenotype was also found in human AMs. Taken together, we conclude that AMs in the aged host harbor a senescence-like phenotype, potentially mediated by the activity of CBF{beta}. HighlightsO_LIscRNAseq revealed Alveolar Macrophage (AM) heterogeneity and self-renewal C_LIO_LICBF{beta} is associated with AM cell cycle and facilitate AM self-renewal C_LIO_LIAMs displayed a senescence-like phenotype during physiological Aging C_LIO_LIAging impairs CBF{beta} expression in mouse and human AMs C_LI

immunology↗

bioRxiv2022

BIN2 phosphorylates the Thr280 of CO to restrict its function in promoting Arabidopsis flowering

CONSTANS (CO) is a central regulator of floral initiation in response to photoperiod. In this study, we show that the GSK3 kinase BIN2 physically interacts with CO and the gain-of-function mutant bin2-1 displays late flowering phenotype through down-regulation of FT transcription. Genetic analyses show that BIN2 genetically acts upstream of CO in regulating flowering time. Further, we illustrate that BIN2 phosphorylates the Thr280 residue of CO. Importantly, the BIN2 phosphorylation of Thr280 residue restricts the function of CO in promoting flowering. Moreover, we reveal that the N-terminal part of CO harboring the B-Box domain mediates the interaction of both CO-CO and BIN2-CO. We find that BIN2 inhibits the formation of CO dimer/oligomer. Taken together, this study reveals that BIN2 regulates flowering time through phosphorylating the Thr280 of CO and inhibiting the CO-CO interaction in Arabidopsis. HighlightBIN2 regulates flowering time through phosphorylating the Thr280 of CO in Arabidopsis.

molecular biology↗

bioRxiv2022

Self-avoidance alone does not explain the function of Dscam1 in mushroom body axonal wiring

Alternative splicing of Drosophila Dscam1 into 38,016 isoforms provides neurons with a unique molecular code for self-recognition and self-avoidance. A canonical model suggests that homophilic binding of identical Dscam1 isoforms on sister branches of mushroom body (MB) axons supports segregation with high fidelity, even when only a single isoform is expressed. Here we generated a series of mutant flies with a single exon 4, 6, or 9 variant, encoding 1,584, 396, or 576 potential isoforms, respectively. Surprisingly, most of the mutants in the latter two groups exhibited obvious defects in the growth, branching, and segregation of MB axonal sister branches. This demonstrates that repertoires of 396 and 576 Dscam1 isoforms were not sufficient for normal patterning of axonal branches. Moreover, reducing Dscam1 levels largely reversed the defects caused by reduced isoform diversity, suggesting a functional link between Dscam1 expression levels and isoform diversity. Taken together, these results indicate that canonical self-avoidance alone does not explain the function of Dscam1 in MB axonal wiring.

neuroscience↗

bioRxiv2022

Cis mutagenesis in vivo reveals extensive noncanonical functions of Dscam1 isoforms in neuronal wiring

Drosophila Dscam1 encodes ten thousand of cell recognition molecules via alternative splicing, which is required for nervous function. However, the underlying mechanism has not fully understood. Here we revealed extensive noncanonical functions of Dscam1 isoform diversity in neuronal wiring. We generated a series of allelic cis mutations in Dscam1, encoding normal number of isoforms albeit with altered isoform composition. Despite normal dendritic self-avoidance and self/non-self discrimination in da neurons, which is consistent with canonical self-avoidance model, these mutants exhibited strikingly distinct spectra of phenotypic defects in three classes of neurons: up to [~]60% defects in mushroom bodies, a significantly increased branching and growth in da neurons, and mild axonal branching defects in mechanosensory neurons. These data suggest that proper Dscam1 isoform composition is required for axon and dendrite growth in diverse neurons. This unprecedented splicing-tuned regulation unlocks new insights into the molecular mechanisms that Dscam1 isoform diversity is engaged in.

neuroscience↗