ABSTRACT
Thalamic dysfunction has been implicated in multiple psychiatric disorders. We sought to study the mechanisms by which abnormalities emerge in the context of the 22q11.2 microdeletion, which confers significant genetic risk for psychiatric disorders. We investigated early stages of human thalamus development using human pluripotent stem cell-derived organoids and show that the 22q11.2 microdeletion underlies widespread transcriptional dysregulation associated with psychiatric disorders in thalamic neurons and glia, including elevated expression of FOXP2. Using an organoid co-culture model, we demonstrate that the 22q11.2 microdeletion mediates an overgrowth of thalamic axons in a FOXP2-dependent manner. Finally, we identify ROBO2 as a candidate molecular mediator of the effects of FOXP2 overexpression on thalamic axon overgrowth. Together, our study suggests that early steps in thalamic development are dysregulated in a model of genetic risk for schizophrenia and contribute to neural phenotypes in 22q11.2 deletion syndrome.
Subject(s)
DiGeorge Syndrome , Schizophrenia , Humans , Schizophrenia/genetics , DiGeorge Syndrome/genetics , DiGeorge Syndrome/psychology , PhenotypeABSTRACT
The thalamus plays a central coordinating role in the brain. Thalamic neurons are organized into spatially distinct nuclei, but the molecular architecture of thalamic development is poorly understood, especially in humans. To begin to delineate the molecular trajectories of cell fate specification and organization in the developing human thalamus, we used single-cell and multiplexed spatial transcriptomics. We show that molecularly defined thalamic neurons differentiate in the second trimester of human development and that these neurons organize into spatially and molecularly distinct nuclei. We identified major subtypes of glutamatergic neuron subtypes that are differentially enriched in anatomically distinct nuclei and six subtypes of γ-aminobutyric acid-mediated (GABAergic) neurons that are shared and distinct across thalamic nuclei.
Subject(s)
GABAergic Neurons , Neurogenesis , Thalamus , Humans , Thalamic Nuclei/cytology , Thalamic Nuclei/growth & development , Thalamus/cytology , Thalamus/growth & development , GABAergic Neurons/physiology , Female , Pregnancy , Single-Cell Analysis , Pregnancy Trimester, SecondABSTRACT
The thalamus plays a central coordinating role in the brain. Thalamic neurons are organized into spatially-distinct nuclei, but the molecular architecture of thalamic development is poorly understood, especially in humans. To begin to delineate the molecular trajectories of cell fate specification and organization in the developing human thalamus, we used single cell and multiplexed spatial transcriptomics. Here we show that molecularly-defined thalamic neurons differentiate in the second trimester of human development, and that these neurons organize into spatially and molecularly distinct nuclei. We identify major subtypes of glutamatergic neuron subtypes that are differentially enriched in anatomically distinct nuclei. In addition, we identify six subtypes of GABAergic neurons that are shared and distinct across thalamic nuclei. One-Sentence Summary: Single cell and spatial profiling of the developing thalamus in the first and second trimester yields molecular mechanisms of thalamic nuclei development.
ABSTRACT
AIM: To develop and validate a radiomics nomogram for identifying high-risk carotid plaques on computed tomography (CT) angiography (CTA). MATERIALS AND METHODS: A total of 280 patients with symptomatic (n=131) and asymptomatic (n=139) carotid plaques were divided into a training set (n=135), validation set (n=58), and external test set (n=87). Radiomic features were extracted from CTA images. A radiomics model was constructed based on selected features and a radiomics score (rad-score) was calculated. A clinical factor model was constructed by demographics and CT findings. A radiomics nomogram combining independent clinical factors and the rad-score was constructed. The diagnostic performance of three models was evaluated and validated by region of characteristic curves. RESULTS: Calcification and maximum plaque thickness were the independent clinical factors. Twenty-four features were used to build the radiomics signature. In the validation set, the nomogram (area under the curve [AUC], 0.977; 95% CI, 0.899-0.999) performed better (p=0.017 and p=0.031) than the clinical factor model (AUC, 0.862; 95% CI, 0.746-0.938) and radiomics signature (AUC, 0.944; 95% CI, 0.850-0.987). In external test set, the nomogram (AUC, 0.952; 95% CI, 0.884-0.987) and radiomics signature (AUC, 0.932; 95% CI, 0.857-0.975) showed better discrimination capability (p=0.002 and p=0.037) than clinical factor model (AUC, 0.818; 95% CI, 0.721-0.892). CONCLUSION: The CT-based nomogram showed satisfactory performance in identification of high-risk plaques in carotid arteries, and it may serve as a potential non-invasive tool to identify carotid plaque vulnerability and risk stratification.
ABSTRACT
Rubella virus is an important human pathogen that can cause neurological deficits in a developing fetus when contracted during pregnancy. Despite successful vaccination programs in the Americas and many developed countries, rubella remains endemic in many regions worldwide and outbreaks occur wherever population immunity is insufficient. Intense interest since rubella virus was first isolated in 1962 has advanced our understanding of clinical outcomes after infection disrupts key processes of fetal neurodevelopment. Yet it is still largely unknown which cell types in the developing brain are targeted. We show that in human brain slices, rubella virus predominantly infects microglia. This infection occurs in a heterogeneous population but not in a highly microglia-enriched monoculture in the absence of other cell types. By using an organoid-microglia model, we further demonstrate that rubella virus infection leads to a profound interferon response in non-microglial cells, including neurons and neural progenitor cells, and this response is attenuated by the presence of microglia.
Subject(s)
Neural Stem Cells , Rubella , Pregnancy , Female , Humans , Rubella virus , Microglia , Rubella/epidemiology , Rubella/metabolism , Neural Stem Cells/metabolism , Organoids/metabolismABSTRACT
Most genetic studies consider autism spectrum disorder (ASD) and developmental disorder (DD) separately despite overwhelming comorbidity and shared genetic etiology. Here, we analyzed de novo variants (DNVs) from 15,560 ASD (6,557 from SPARK) and 31,052 DD trios independently and also combined as broader neurodevelopmental disorders (NDDs) using three models. We identify 615 NDD candidate genes (false discovery rate [FDR] < 0.05) supported by ≥1 models, including 138 reaching Bonferroni exome-wide significance (P < 3.64e-7) in all models. The genes group into five functional networks associating with different brain developmental lineages based on single-cell nuclei transcriptomic data. We find no evidence for ASD-specific genes in contrast to 18 genes significantly enriched for DD. There are 53 genes that show mutational bias, including enrichments for missense (n = 41) or truncating (n = 12) DNVs. We also find 10 genes with evidence of male- or female-bias enrichment, including 4 X chromosome genes with significant female burden (DDX3X, MECP2, WDR45, and HDAC8). This large-scale integrative analysis identifies candidates and functional subsets of NDD genes.
Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Child , Male , Female , Humans , Autistic Disorder/genetics , Autism Spectrum Disorder/genetics , Developmental Disabilities/genetics , Genetic Predisposition to Disease , Exome , Histone Deacetylases/genetics , Repressor Proteins/genetics , Carrier Proteins/geneticsABSTRACT
Objective: To analyze the clinicopathological features of IgG4-related diseases (RD) of retroperitoneum and the urinary and male reproductive system (IgG4-RUMR). Methods: A total of 11 IgG4-RUMR cases from January 2013 to March 2021 were retrospectively collected at Peking University Third Hospital and Shandong Provincial Hospital affiliated to Shandong First Medical University. The clinicopathologic features, laboratory and imaging findings were analyzed and scored according to the 2019 ACR/EULAR classification criteria for IgG4-RD. Results: The 11 patients (male:female is 9â¶2; mean age 59 years, range from 44 to 83 years) were initially admitted to the Deparment of Urology/Kidney Transplantation (10 cases) and the Department of Oncology (1 case). All patients had urogenital disorders or imaging abnormalities. Three of the 11 patients had a history of IgG4-RD such as lacrimal gland engorgement, salivary gland engorgement and IgG4-associated pancreatitis. Abnormal retroperitoneal soft tissue and hydronephrosis were found in eight cases, while epididymal and spermatic cord masses were found in one case, simple renal mass in one case, and"benign prostatic hyperplasia"in one case. In the 10 patients tested for serum IgG4, the serum IgG4 level was 0.8-14.4 g/L. Histologically, all cases showed significant lymphoplasmacytic infiltration and storiform fibrosis, and some were accompanied by obliterative phlebitis. The number of IgG4 positive plasma cells was 12-155 per high-power field, and the IgG4/IgG ratio was 15%-77%. According to the 2019 ACR/EULAR IgG4-RD classification standard 11 cases scored 20-48 points, all of which met the diagnostic criteria of IgG4-RUMR. Therapeutically, the patient with a simple renal mass underwent partial nephrectomy. The patient with prostate lesion underwent transurethral resection of prostate and was initially diagnosed as nonspecific chronic prostatitis. Later, the patient was admitted again because of salivary gland swelling, and the pathologic diagnosis was amended. The patient with epididymal and spermatic cord masses participated in a clinical trial about retroperitoneal fibrosis. The remaining eight patients received symptomatic treatment such as adhesiolysis and stent placement. All the patients were subsequently treated with glucocorticoid/immunosuppressant and symptoms relieved. Conclusions: IgG4-RUMR is uncommon. In clinical practice, information from clinical, serologic, radiologic and pathologic evaluations must be integrated. IgG4-RUMR should be considered in the differential diagnosis of urinary and male reproductive diseases. The 2019 ACR/EULAR classification criteria for IgG4-RD, while relatively complex, are objective and practical in the diagnosis of IgG4-RUMR.
Subject(s)
Autoimmune Diseases , Immunoglobulin G4-Related Disease , Transurethral Resection of Prostate , Adult , Aged , Aged, 80 and over , Autoimmune Diseases/diagnosis , Autoimmune Diseases/pathology , Female , Glucocorticoids , Humans , Immunoglobulin G , Immunoglobulin G4-Related Disease/pathology , Immunosuppressive Agents , Male , Middle Aged , Prostate/pathology , Retrospective StudiesABSTRACT
A cell's shape and motion represent fundamental aspects of cell identity and can be highly predictive of function and pathology. However, automated analysis of the morphodynamic states remains challenging for most cell types, especially primary human cells where genetic labeling may not be feasible. To enable automated and quantitative analysis of morphodynamic states, we developed DynaMorph-a computational framework that combines quantitative live cell imaging with self-supervised learning. To demonstrate the robustness and utility of this approach, we used DynaMorph to annotate morphodynamic states observed with label-free measurements of optical density and anisotropy of live microglia isolated from human brain tissue. These cells show complex behavior and have varied responses to disease-relevant perturbations. DynaMorph generates quantitative morphodynamic representations that can be used to compare the effects of the perturbations. Using DynaMorph, we identify distinct morphodynamic states of microglia polarization and detect rare transition events between states. The concepts and the methods presented here can facilitate automated discovery of functional states of diverse cellular systems.
Subject(s)
Brain , Supervised Machine Learning , Anisotropy , HumansABSTRACT
Cerebrovascular diseases are a leading cause of death and neurologic disability. Further understanding of disease mechanisms and therapeutic strategies requires a deeper knowledge of cerebrovascular cells in humans. We profiled transcriptomes of 181,388 cells to define a cell atlas of the adult human cerebrovasculature, including endothelial cell molecular signatures with arteriovenous segmentation and expanded perivascular cell diversity. By leveraging this reference, we investigated cellular and molecular perturbations in brain arteriovenous malformations, which are a leading cause of stroke in young people, and identified pathologic endothelial transformations with abnormal vascular patterning and the ontology of vascularly derived inflammation. We illustrate the interplay between vascular and immune cells that contributes to brain hemorrhage and catalog opportunities for targeting angiogenic and inflammatory programs in vascular malformations.
Subject(s)
Blood Vessels/cytology , Brain/blood supply , Intracranial Arteriovenous Malformations/pathology , Transcriptome , Adult , Blood Vessels/pathology , Blood Vessels/physiology , Blood Vessels/physiopathology , Cells, Cultured , Cerebral Cortex/blood supply , Cerebral Hemorrhage/pathology , Cerebral Hemorrhage/physiopathology , Cerebrovascular Circulation , Endothelial Cells/cytology , Endothelial Cells/pathology , Endothelial Cells/physiology , Fibroblasts/cytology , Fibroblasts/physiology , Humans , Inflammation , Intracranial Arteriovenous Malformations/metabolism , Monocytes/cytology , Monocytes/physiology , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/pathology , Muscle, Smooth, Vascular/physiology , Pericytes/cytology , Pericytes/physiology , RNA-Seq , Single-Cell AnalysisABSTRACT
During mammalian development, differences in chromatin state coincide with cellular differentiation and reflect changes in the gene regulatory landscape1. In the developing brain, cell fate specification and topographic identity are important for defining cell identity2 and confer selective vulnerabilities to neurodevelopmental disorders3. Here, to identify cell-type-specific chromatin accessibility patterns in the developing human brain, we used a single-cell assay for transposase accessibility by sequencing (scATAC-seq) in primary tissue samples from the human forebrain. We applied unbiased analyses to identify genomic loci that undergo extensive cell-type- and brain-region-specific changes in accessibility during neurogenesis, and an integrative analysis to predict cell-type-specific candidate regulatory elements. We found that cerebral organoids recapitulate most putative cell-type-specific enhancer accessibility patterns but lack many cell-type-specific open chromatin regions that are found in vivo. Systematic comparison of chromatin accessibility across brain regions revealed unexpected diversity among neural progenitor cells in the cerebral cortex and implicated retinoic acid signalling in the specification of neuronal lineage identity in the prefrontal cortex. Together, our results reveal the important contribution of chromatin state to the emerging patterns of cell type diversity and cell fate specification and provide a blueprint for evaluating the fidelity and robustness of cerebral organoids as a model for cortical development.
Subject(s)
Brain/cytology , Epigenomics , Neurogenesis , Single-Cell Analysis , Atlases as Topic , Brain/growth & development , Brain/metabolism , Chromatin/chemistry , Chromatin/genetics , Chromatin/metabolism , Disease Susceptibility , Enhancer Elements, Genetic , Humans , Neurons/cytology , Neurons/metabolism , Organoids/cytology , Tretinoin/metabolismABSTRACT
Microglia are resident macrophages in the brain that emerge in early development and respond to the local environment by altering their molecular and phenotypic states. Fundamental questions about microglia diversity and function during development remain unanswered because we lack experimental strategies to interrogate their interactions with other cell types and responses to perturbations ex vivo. We compared human microglia states across culture models, including cultured primary and pluripotent stem cell-derived microglia. We developed a "report card" of gene expression signatures across these distinct models to facilitate characterization of their responses across experimental models, perturbations, and disease conditions. Xenotransplantation of human microglia into cerebral organoids allowed us to characterize key transcriptional programs of developing microglia in vitro and reveal that microglia induce transcriptional changes in neural stem cells and decrease interferon signaling response genes. Microglia additionally accelerate the emergence of synchronized oscillatory network activity in brain organoids by modulating synaptic density.
Subject(s)
Induced Pluripotent Stem Cells , Neural Stem Cells , Brain , Cell Differentiation , Humans , Microglia , Models, Theoretical , OrganoidsABSTRACT
Sleep disturbances in autism and neurodevelopmental disorders are common and adversely affect patient's quality of life, yet the underlying mechanisms are understudied. We found that individuals with mutations in CHD8, among the highest-confidence autism risk genes, or CHD7 suffer from disturbed sleep maintenance. These defects are recapitulated in Drosophila mutants affecting kismet, the sole CHD8/CHD7 ortholog. We show that Kismet is required in glia for early developmental and adult sleep architecture. This role localizes to subperineurial glia constituting the blood-brain barrier. We demonstrate that Kismet-related sleep disturbances are caused by high serotonin during development, paralleling a well-established but genetically unsolved autism endophenotype. Despite their developmental origin, Kismet's sleep architecture defects can be reversed in adulthood by a behavioral regime resembling human sleep restriction therapy. Our findings provide fundamental insights into glial regulation of sleep and propose a causal mechanistic link between the CHD8/CHD7/Kismet family, developmental hyperserotonemia, and autism-associated sleep disturbances.
Subject(s)
Autistic Disorder , DNA-Binding Proteins , Animals , Autistic Disorder/genetics , Blood-Brain Barrier/metabolism , DNA Helicases/metabolism , DNA-Binding Proteins/metabolism , Drosophila/metabolism , Neuroglia/metabolism , Quality of Life , Serotonin , Sleep , Transcription Factors/metabolismABSTRACT
BACKGROUND: With the increasing number of genomic sequencing studies, hundreds of genes have been implicated in neurodevelopmental disorders (NDDs). The rate of gene discovery far outpaces our understanding of genotype-phenotype correlations, with clinical characterization remaining a bottleneck for understanding NDDs. Most disease-associated Mendelian genes are members of gene families, and we hypothesize that those with related molecular function share clinical presentations. METHODS: We tested our hypothesis by considering gene families that have multiple members with an enrichment of de novo variants among NDDs, as determined by previous meta-analyses. One of these gene families is the heterogeneous nuclear ribonucleoproteins (hnRNPs), which has 33 members, five of which have been recently identified as NDD genes (HNRNPK, HNRNPU, HNRNPH1, HNRNPH2, and HNRNPR) and two of which have significant enrichment in our previous meta-analysis of probands with NDDs (HNRNPU and SYNCRIP). Utilizing protein homology, mutation analyses, gene expression analyses, and phenotypic characterization, we provide evidence for variation in 12 HNRNP genes as candidates for NDDs. Seven are potentially novel while the remaining genes in the family likely do not significantly contribute to NDD risk. RESULTS: We report 119 new NDD cases (64 de novo variants) through sequencing and international collaborations and combined with published clinical case reports. We consider 235 cases with gene-disruptive single-nucleotide variants or indels and 15 cases with small copy number variants. Three hnRNP-encoding genes reach nominal or exome-wide significance for de novo variant enrichment, while nine are candidates for pathogenic mutations. Comparison of HNRNP gene expression shows a pattern consistent with a role in cerebral cortical development with enriched expression among radial glial progenitors. Clinical assessment of probands (n = 188-221) expands the phenotypes associated with HNRNP rare variants, and phenotypes associated with variation in the HNRNP genes distinguishes them as a subgroup of NDDs. CONCLUSIONS: Overall, our novel approach of exploiting gene families in NDDs identifies new HNRNP-related disorders, expands the phenotypes of known HNRNP-related disorders, strongly implicates disruption of the hnRNPs as a whole in NDDs, and supports that NDD subtypes likely have shared molecular pathogenesis. To date, this is the first study to identify novel genetic disorders based on the presence of disorders in related genes. We also perform the first phenotypic analyses focusing on related genes. Finally, we show that radial glial expression of these genes is likely critical during neurodevelopment. This is important for diagnostics, as well as developing strategies to best study these genes for the development of therapeutics.
Subject(s)
Genetic Predisposition to Disease , Heterogeneous-Nuclear Ribonucleoproteins/genetics , Mutation/genetics , Neurodevelopmental Disorders/genetics , Brain/metabolism , DNA Copy Number Variations/genetics , Gene Expression Regulation , Genetic Association Studies , Genetic Variation , Heterogeneous-Nuclear Ribonucleoproteins/metabolism , Humans , Inheritance Patterns/genetics , Mutation, Missense/genetics , Phenotype , RNA Processing, Post-Transcriptional/genetics , Single-Cell AnalysisABSTRACT
AIMS: Single oral dose anti-arrhythmic drugs (AADs) are used to cardiovert recent-onset atrial fibrillation (AF); however, the optimal agent is uncertain. METHODS: We performed a systematic review and network meta-analysis of randomized trials testing single oral dose AADs vs. any comparator to cardiovert AF <7 days duration. We searched MEDLINE, Embase, and CENTRAL to April 2020. The primary outcome was successful cardioversion at timepoint nearest 8 h after administration. RESULTS: From 12 712 citations, 22 trials (2320 patients) were included. Thirteen trials included patients with some degree of heart failure; 19 included patients with some degree of ischaemic heart disease vs. placebo or rate-control (32% success) at 8 h, flecainide [73%, network odds ratio (OR) 7.6, 95% credible interval (CrI) 4.4-14.0], propafenone (70%, OR 4.6, CrI 2.9-7.3), and pilsicainide (59%, OR 10.0, CrI 1.8-69.0), but not amiodarone (28%, OR 1.0, CrI 0.4-2.8) were superior. Flecainide (OR 7.5, CrI 2.6-24.0) and propafenone (OR 4.5, CrI 1.6-13.0) were superior to amiodarone; propafenone vs. flecainide did not statistically differ (OR 0.6, CrI 0.3-1.1). At longest follow-up, amiodarone was superior to placebo (OR 11.0, CrI 3.2-41.0), flecainide vs. amiodarone (OR 0.79, CrI 0.19-3.1), and propafenone vs. amiodarone (OR 0.36, CrI 0.092-1.4) were not statistically different, and flecainide was superior to propafenone (OR 2.2, CrI 1.1-4.8). Atrial and ventricular tachyarrhythmias, bradyarrhythmias, and hypotension were rare with PO AADs. CONCLUSION: Single oral dose Class 1C AADs are effective and safe for cardioversion of recent-onset AF. Flecainide may be superior to propafenone. Amiodarone is a slower acting alternative.
Subject(s)
Amiodarone , Atrial Fibrillation , Pharmaceutical Preparations , Anti-Arrhythmia Agents/adverse effects , Atrial Fibrillation/diagnosis , Atrial Fibrillation/drug therapy , Electric Countershock , Humans , Network Meta-Analysis , Propafenone/adverse effects , Randomized Controlled Trials as TopicABSTRACT
The objective of this study was to investigate the use of optical coherence tomography (OCT) for monitoring changes in the structure of caries lesions overtime after treatment with silver diamine fluoride (SDF). Artificial caries lesions were formed on dentin bovine blocks. Each block was partitioned into 5 windows: one lesion was covered by nail varnish as control (LC), one sound window was covered with nail varnish (SC), one sound window was exposed to SDF (SCT), one lesion received 2 applications of SDF (L2), while the other lesion received one application of SDF (L1). Each window was scanned using OCT before SDF application, and every week subsequently, for 12 weeks after initial SDF treatment. Parameters such as mean intensity and the width of the peak of increased reflectivity located at the sample surface and the intensity at a depth of 180-µm were monitored. High-resolution microscopy was also used to for the analysis of selected samples. Changes in the parameters measured showed significant changes on dentin lesions after SDF application. OCT resolved structural changes after SDF application as well as changes overtime. High resolution microscopy images confirm penetration of SDF into the samples. Such changes can potentially be monitored to determine if and when re-application of SDF is needed.
ABSTRACT
OBJECTIVE: This study aimed to investigate the reversal effect of verapamil (VER) on the chemoresistance to cisplatin of esophageal squamous cell carcinoma (ESCC) cells. PATIENTS AND METHODS: The reversal effect of VER on cisplatin resistance in ESCC cells was evaluated via CCK-8 assay, colony formation assessment, and flow cytometry. The key genes that mediate this effect were screened via high-throughput transcriptome se¬quencing. The mRNA and protein expression levels of potassium calcium-activated channel subfamily M alpha 1 (KCNMA1) in ESCC cells were examined via quantitative real-time PCR and Western blot analysis, respectively. The protein expressions of KCNMA1 in tissue samples from patients with either positive or negative responses to the therapeutic regimen of VER were determined via immunohistochemistry assay. Cell models with KCNMA1 knockdown and overexpression were es¬tablished to examine the role of KCNMA1 in mediating the reversal effect of VER on the chemoresistance to cisplatin of ESCC cells. RESULTS: Results revealed that VER significantly decreased the 50% inhibitory concentration of cisplatin, inhibited colony formation, and induced apoptosis in ESCC cells. The curative effects of VER combined with chemotherapeutic drugs in KCNMA1-positive patients were better than those in KCNMA1-negative patients. KCNMA1 upregulation enhanced the reversal effect of VER on the chemoresistance to cisplatin of ESCC cells. CONCLUSIONS: KCNMA1 facilitated the reversal effect of VER on cisplatin resistance in ESCC cells.
Subject(s)
Esophageal Neoplasms/metabolism , Esophageal Squamous Cell Carcinoma/metabolism , Large-Conductance Calcium-Activated Potassium Channel alpha Subunits/metabolism , Up-Regulation , Adolescent , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Survival/drug effects , Cisplatin/chemistry , Cisplatin/pharmacology , Drug Resistance, Neoplasm/drug effects , Esophageal Neoplasms/drug therapy , Esophageal Neoplasms/pathology , Esophageal Squamous Cell Carcinoma/drug therapy , Esophageal Squamous Cell Carcinoma/pathology , Female , Humans , Male , Middle Aged , Tumor Cells, Cultured , Verapamil/chemistry , Verapamil/pharmacology , Young AdultABSTRACT
Bumblebees are a diverse group of globally important pollinators in natural ecosystems and for agricultural food production. With both eusocial and solitary life-cycle phases, and some social parasite species, they are especially interesting models to understand social evolution, behavior, and ecology. Reports of many species in decline point to pathogen transmission, habitat loss, pesticide usage, and global climate change, as interconnected causes. These threats to bumblebee diversity make our reliance on a handful of well-studied species for agricultural pollination particularly precarious. To broadly sample bumblebee genomic and phenotypic diversity, we de novo sequenced and assembled the genomes of 17 species, representing all 15 subgenera, producing the first genus-wide quantification of genetic and genomic variation potentially underlying key ecological and behavioral traits. The species phylogeny resolves subgenera relationships, whereas incomplete lineage sorting likely drives high levels of gene tree discordance. Five chromosome-level assemblies show a stable 18-chromosome karyotype, with major rearrangements creating 25 chromosomes in social parasites. Differential transposable element activity drives changes in genome sizes, with putative domestications of repetitive sequences influencing gene coding and regulatory potential. Dynamically evolving gene families and signatures of positive selection point to genus-wide variation in processes linked to foraging, diet and metabolism, immunity and detoxification, as well as adaptations for life at high altitudes. Our study reveals how bumblebee genes and genomes have evolved across the Bombus phylogeny and identifies variations potentially linked to key ecological and behavioral traits of these important pollinators.