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1.
Cell ; 170(4): 748-759.e12, 2017 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-28802044

RESUMO

Social insects are emerging models to study how gene regulation affects behavior because their colonies comprise individuals with the same genomes but greatly different behavioral repertoires. To investigate the molecular mechanisms that activate distinct behaviors in different castes, we exploit a natural behavioral plasticity in Harpegnathos saltator, where adult workers can transition to a reproductive, queen-like state called gamergate. Analysis of brain transcriptomes during the transition reveals that corazonin, a neuropeptide homologous to the vertebrate gonadotropin-releasing hormone, is downregulated as workers become gamergates. Corazonin is also preferentially expressed in workers and/or foragers from other social insect species. Injection of corazonin in transitioning Harpegnathos individuals suppresses expression of vitellogenin in the brain and stimulates worker-like hunting behaviors, while inhibiting gamergate behaviors, such as dueling and egg deposition. We propose that corazonin is a central regulator of caste identity and behavior in social insects.


Assuntos
Formigas/metabolismo , Proteínas de Insetos/metabolismo , Neuropeptídeos/metabolismo , Animais , Formigas/genética , Formigas/crescimento & desenvolvimento , Comportamento Animal , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Comportamento Social
2.
Cell ; 171(3): 522-539.e20, 2017 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-28942923

RESUMO

Understanding the organizational logic of neural circuits requires deciphering the biological basis of neuronal diversity and identity, but there is no consensus on how neuron types should be defined. We analyzed single-cell transcriptomes of a set of anatomically and physiologically characterized cortical GABAergic neurons and conducted a computational genomic screen for transcriptional profiles that distinguish them from one another. We discovered that cardinal GABAergic neuron types are delineated by a transcriptional architecture that encodes their synaptic communication patterns. This architecture comprises 6 categories of ∼40 gene families, including cell-adhesion molecules, transmitter-modulator receptors, ion channels, signaling proteins, neuropeptides and vesicular release components, and transcription factors. Combinatorial expression of select members across families shapes a multi-layered molecular scaffold along the cell membrane that may customize synaptic connectivity patterns and input-output signaling properties. This molecular genetic framework of neuronal identity integrates cell phenotypes along multiple axes and provides a foundation for discovering and classifying neuron types.


Assuntos
Neurônios GABAérgicos/citologia , Perfilação da Expressão Gênica , Análise de Célula Única , Animais , Moléculas de Adesão Celular Neuronais/metabolismo , Matriz Extracelular/metabolismo , Neurônios GABAérgicos/metabolismo , Camundongos , Receptores de GABA/metabolismo , Receptores Ionotrópicos de Glutamato/metabolismo , Transdução de Sinais , Sinapses , Transcrição Gênica , Zinco/metabolismo , Ácido gama-Aminobutírico/metabolismo
3.
Immunity ; 52(6): 1105-1118.e9, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32553173

RESUMO

The challenges in recapitulating in vivo human T cell development in laboratory models have posed a barrier to understanding human thymopoiesis. Here, we used single-cell RNA sequencing (sRNA-seq) to interrogate the rare CD34+ progenitor and the more differentiated CD34- fractions in the human postnatal thymus. CD34+ thymic progenitors were comprised of a spectrum of specification and commitment states characterized by multilineage priming followed by gradual T cell commitment. The earliest progenitors in the differentiation trajectory were CD7- and expressed a stem-cell-like transcriptional profile, but had also initiated T cell priming. Clustering analysis identified a CD34+ subpopulation primed for the plasmacytoid dendritic lineage, suggesting an intrathymic dendritic specification pathway. CD2 expression defined T cell commitment stages where loss of B cell potential preceded that of myeloid potential. These datasets delineate gene expression profiles spanning key differentiation events in human thymopoiesis and provide a resource for the further study of human T cell development.


Assuntos
Diferenciação Celular/genética , Linhagem da Célula/genética , Linfopoese/genética , Linfócitos T/metabolismo , Timócitos/metabolismo , Animais , Biomarcadores , Biologia Computacional , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Imunofenotipagem , Camundongos , Análise de Célula Única , Linfócitos T/citologia , Timócitos/citologia , Transcriptoma
4.
Proc Natl Acad Sci U S A ; 121(19): e2311685121, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38683994

RESUMO

Neural crest cells exemplify cellular diversification from a multipotent progenitor population. However, the full sequence of early molecular choices orchestrating the emergence of neural crest heterogeneity from the embryonic ectoderm remains elusive. Gene-regulatory-networks (GRN) govern early development and cell specification toward definitive neural crest. Here, we combine ultradense single-cell transcriptomes with machine-learning and large-scale transcriptomic and epigenomic experimental validation of selected trajectories, to provide the general principles and highlight specific features of the GRN underlying neural crest fate diversification from induction to early migration stages using Xenopus frog embryos as a model. During gastrulation, a transient neural border zone state precedes the choice between neural crest and placodes which includes multiple converging gene programs. During neurulation, transcription factor connectome, and bifurcation analyses demonstrate the early emergence of neural crest fates at the neural plate stage, alongside an unbiased multipotent-like lineage persisting until epithelial-mesenchymal transition stage. We also decipher circuits driving cranial and vagal neural crest formation and provide a broadly applicable high-throughput validation strategy for investigating single-cell transcriptomes in vertebrate GRNs in development, evolution, and disease.


Assuntos
Crista Neural , Análise de Célula Única , Xenopus laevis , Animais , Crista Neural/citologia , Crista Neural/metabolismo , Análise de Célula Única/métodos , Xenopus laevis/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Movimento Celular , Redes Reguladoras de Genes , Transcriptoma , Gastrulação , Placa Neural/metabolismo , Placa Neural/embriologia , Placa Neural/citologia , Transição Epitelial-Mesenquimal/genética , Embrião não Mamífero/metabolismo , Embrião não Mamífero/citologia , Neurulação/genética , Neurulação/fisiologia , Diferenciação Celular
5.
Plant J ; 118(4): 997-1015, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38281284

RESUMO

Endoreduplication, during which cells increase their DNA content through successive rounds of full genome replication without cell division, is the major source of endopolyploidy in higher plants. Endoreduplication plays pivotal roles in plant growth and development and is associated with the activation of specific transcriptional programmes that are characteristic of each cell type, thereby defining their identity. In plants, endoreduplication is found in numerous organs and cell types, especially in agronomically valuable ones, such as the fleshy fruit (pericarp) of tomato presenting high ploidy levels. We used the tomato pericarp tissue as a model system to explore the transcriptomes associated with endoreduplication progression during fruit growth. We confirmed that expression globally scales with ploidy level and identified sets of differentially expressed genes presenting only developmental-specific, only ploidy-specific expression patterns or profiles resulting from an additive effect of ploidy and development. When comparing ploidy levels at a specific developmental stage, we found that non-endoreduplicated cells are defined by cell division state and cuticle synthesis while endoreduplicated cells are mainly defined by their metabolic activity changing rapidly over time. By combining this dataset with publicly available spatiotemporal pericarp expression data, we proposed a map describing the distribution of ploidy levels within the pericarp. These transcriptome-based predictions were validated by quantifying ploidy levels within the pericarp tissue. This in situ ploidy quantification revealed the dynamic progression of endoreduplication and its cell layer specificity during early fruit development. In summary, the study sheds light on the complex relationship between endoreduplication, cell differentiation and gene expression patterns in the tomato pericarp.


Assuntos
Endorreduplicação , Frutas , Regulação da Expressão Gênica de Plantas , Ploidias , Solanum lycopersicum , Transcriptoma , Solanum lycopersicum/genética , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Endorreduplicação/genética , Perfilação da Expressão Gênica , Divisão Celular/genética
6.
Front Neuroendocrinol ; 72: 101115, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37993020

RESUMO

Bipolar disorder (BD) is worldwide a prevalent mental illness and a leading risk factor for suicide. Over the past three decades, it has been discovered that sex differences exist throughout the entire panorama of BD, but the etiologic regions and mechanisms that generate such differences remain poorly characterized. Available evidence indicates that the dorsolateral prefrontal cortex (DLPFC), a critical region that controls higher-order cognitive processing and mood, exhibits biological disparities between male and female patients with psychiatric disorders, which are highly correlated with the co-occurrence of psychotic symptoms. This review addresses the sex differences in BD concerning epidemiology, cognitive impairments, clinical manifestations, neuroimaging, and laboratory abnormalities. It also provides strong evidence linking DLPFC to the etiopathogenesis of these sex differences. We emphasize the importance of identifying gene signatures using human brain transcriptomics, which can depict sexually different variations, explain sex-biased symptomatic features, and provide novel targets for sex-specific therapeutics.


Assuntos
Transtorno Bipolar , Humanos , Masculino , Feminino , Transtorno Bipolar/etiologia , Córtex Pré-Frontal Dorsolateral , Córtex Pré-Frontal , Caracteres Sexuais , Encéfalo/patologia
7.
Proc Natl Acad Sci U S A ; 119(4)2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35042803

RESUMO

Green plants play a fundamental role in ecosystems, human health, and agriculture. As de novo genomes are being generated for all known eukaryotic species as advocated by the Earth BioGenome Project, increasing genomic information on green land plants is essential. However, setting standards for the generation and storage of the complex set of genomes that characterize the green lineage of life is a major challenge for plant scientists. Such standards will need to accommodate the immense variation in green plant genome size, transposable element content, and structural complexity while enabling research into the molecular and evolutionary processes that have resulted in this enormous genomic variation. Here we provide an overview and assessment of the current state of knowledge of green plant genomes. To date fewer than 300 complete chromosome-scale genome assemblies representing fewer than 900 species have been generated across the estimated 450,000 to 500,000 species in the green plant clade. These genomes range in size from 12 Mb to 27.6 Gb and are biased toward agricultural crops with large branches of the green tree of life untouched by genomic-scale sequencing. Locating suitable tissue samples of most species of plants, especially those taxa from extreme environments, remains one of the biggest hurdles to increasing our genomic inventory. Furthermore, the annotation of plant genomes is at present undergoing intensive improvement. It is our hope that this fresh overview will help in the development of genomic quality standards for a cohesive and meaningful synthesis of green plant genomes as we scale up for the future.


Assuntos
Sequência de Bases/genética , Genômica/tendências , Viridiplantae/genética , Biodiversidade , Evolução Biológica , Elementos de DNA Transponíveis/genética , Ecologia , Ecossistema , Embriófitas/genética , Evolução Molecular , Genoma , Genoma de Planta/genética , Genômica/métodos , Disseminação de Informação/métodos , Armazenamento e Recuperação da Informação/métodos , Filogenia , Plantas/genética
8.
Physiol Genomics ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38975796

RESUMO

Dairy cattle with high (HM) versus low muscle (LM) reserves exhibit distinct temporal changes in longissimus dorsi muscle depth (LDD) in late gestation. Branched-chain volatile fatty acids (BCVFA) supplementation increased blood glucose levels. We hypothesized that differences in HM and LM reflect distinct muscle metabolism and BCVFA supplementation altered metabolic pathways. At 42 d before expected calving (BEC) Holstein dairy cows were enrolled in a 2 x 2 factorial study of diet and muscle reserves, by assigning to control (CON) or BCVFA supplemented diets and LDD of HM (>4.6 cm) or LM (≤4.6 cm) groups: HM-CON (n=13), HM-BCVFA (n=10), LM-CON (n=9), and LM-BCVFA (n=9). Longisumus dorsi was biopsied at 21 d BEC, total RNA isolated and protein coding gene expression measured with RNA-seq. Between HM and LM 713 genes were differentially expressed and 481 between BCVFA and CON (P<0.05). Transcriptional signatures indicated differential distribution of Type II fibers between groups, with MYH1 greater in LM and MYH2 greater in HM cattle (P<0.05). Signatures of LM cattle relative to HM indicated greater activation of autophagy, ubiquitin-proteasome, and Ca2+-calpain pathways. HM cattle displayed greater expression of genes that encode extracellular matrix proteins and factors that regulate their proteolysis and turnover. BCVFA modified transcriptomes by increasing expression of genes that regulate fatty acid degradation and flux of carbons into the TCA cycle as acetyl CoA. Molecular signatures support distinct metabolic strategies between LM and HM cattle, and that BCVFA supplementation increased substrates for energy generation.

9.
Plant J ; 116(1): 269-281, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37390084

RESUMO

Transcriptome profiles in plants are heterogenous at every level of morphological organization. Even within organs, cells of the same type can have different patterns of gene expression depending on where they are positioned within tissues. This heterogeneity is associated with non-uniform distribution of biological processes within organs. The regulatory mechanisms that establish and sustain the spatial heterogeneity are unknown. Here, we identify regulatory modules that support functional specialization of different parts of Oryza sativa cv. Nipponbare leaves by leveraging transcriptome data, transcription factor binding motifs and global gene regulatory network prediction algorithms. We generated a global gene regulatory network in which we identified six regulatory modules that were active in different parts of the leaf. The regulatory modules were enriched for genes involved in spatially relevant biological processes, such as cell wall deposition, environmental sensing and photosynthesis. Strikingly, more than 86.9% of genes in the network were regulated by members of only five transcription factor families. We also generated targeted regulatory networks for the large MYB and bZIP/bHLH families to identify interactions that were masked in the global prediction. This analysis will provide a baseline for future single cell and array-based spatial transcriptome studies and for studying responses to environmental stress and demonstrates the extent to which seven coarse spatial transcriptome analysis can provide insight into the regulatory mechanisms supporting functional specialization within leaves.


Assuntos
Redes Reguladoras de Genes , Oryza , Oryza/metabolismo , Perfilação da Expressão Gênica , Transcriptoma , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Regulação da Expressão Gênica de Plantas/genética
10.
Plant J ; 116(5): 1385-1400, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37713270

RESUMO

Bread wheat, one of the keystone crops for global food security, is challenged by climate change and resource shortage. The root system plays a vital role in water and nutrient absorption, making it essential for meeting the growing global demand. Here, using an association-mapping population composed of 406 accessions, we identified QTrl.Rs-5B modulating seminal root development with a genome-wide association study and validated its genetic effects with two F5 segregation populations. Transcriptome-wide association study prioritized TaFMO1-5B, a gene encoding the flavin-containing monooxygenases, as the causal gene for QTrl.Rs-5B, whose expression levels correlate negatively with the phenotyping variations among our population. The lines silenced for TaFMO1-5B consistently showed significantly larger seminal roots in different genetic backgrounds. Additionally, the agriculture traits measured in multiple environments showed that QTrl.Rs-5B also affects yield component traits and plant architecture-related traits, and its favorable haplotype modulates these traits toward that of modern cultivars, suggesting the application potential of QTrl.Rs-5B for wheat breeding. Consistently, the frequency of the favorable haplotype of QTrl.Rs-5B increased with habitat expansion and breeding improvement of bread wheat. In conclusion, our findings identified and demonstrated the effects of QTrl.Rs-5B on seminal root development and illustrated that it is a valuable genetic locus for wheat root improvement.


Assuntos
Estudo de Associação Genômica Ampla , Locos de Características Quantitativas , Locos de Características Quantitativas/genética , Triticum/genética , Transcriptoma/genética , Pão , Melhoramento Vegetal , Fenótipo , Perfilação da Expressão Gênica , Polimorfismo de Nucleotídeo Único/genética
11.
BMC Genomics ; 25(1): 357, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600449

RESUMO

BACKGROUND: Broodiness significantly impacts poultry egg production, particularly notable in specific breeds such as the black-boned Silky, characterized by pronounced broodiness. An understanding of the alterations in ovarian signaling is essential for elucidating the mechanisms that influence broodiness. However, comparative research on the characteristics of long non-coding RNAs (lncRNAs) in the ovaries of broody chickens (BC) and high egg-laying chickens (GC) remains scant. In this investigation, we employed RNA sequencing to assess the ovarian transcriptomes, which include both lncRNAs and mRNAs, in eight Taihe Black-Bone Silky Fowls (TBsf), categorized into broody and high egg-laying groups. This study aims to provide a clearer understanding of the genetic underpinnings associated with broodiness and egg production. RESULTS: We have identified a total of 16,444 mRNAs and 18,756 lncRNAs, of which 349 mRNAs and 651 lncRNAs exhibited significantly different expression (DE) between the BC and GC groups. Furthermore, we have identified the cis-regulated and trans-regulated target genes of differentially abundant lncRNA transcripts and have constructed an lncRNA-mRNA trans-regulated interaction network linked to ovarian follicle development. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation analyses have revealed that DE mRNAs and the target genes of DE lncRNAs are associated with pathways including neuroactive ligand-receptor interaction, CCR6 chemokine receptor binding, G-protein coupled receptor binding, cytokine-cytokine receptor interaction, and ECM-receptor interaction. CONCLUSION: Our research presents a comprehensive compilation of lncRNAs and mRNAs linked to ovarian development. Additionally, it establishes a predictive interaction network involving differentially abundant lncRNAs and differentially expressed genes (DEGs) within TBsf. This significantly contributes to our understanding of the intricate interactions between lncRNAs and genes governing brooding behavior.


Assuntos
Galinhas , RNA Longo não Codificante , Feminino , Animais , Galinhas/genética , Galinhas/metabolismo , Ovário/metabolismo , RNA Longo não Codificante/metabolismo , Perfilação da Expressão Gênica , RNA Mensageiro/metabolismo , Redes Reguladoras de Genes
12.
Kidney Int ; 105(3): 540-561, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38159678

RESUMO

Clinical studies suggest that non-alcoholic steatohepatitis (NASH) is an independent risk factor for chronic kidney disease (CKD), but causality and mechanisms linking these two major diseases are lacking. To assess whether NASH can induce CKD, we have characterized kidney function, histological features, transcriptomic and lipidomic profiles in a well-validated murine NASH model. Mice with NASH progressively developed significant podocyte foot process effacement, proteinuria, glomerulosclerosis, tubular epithelial cell injury, lipid accumulation, and interstitial fibrosis. The progression of kidney fibrosis paralleled the severity of the histologic NASH-activity score. Significantly, we confirmed the causal link between NASH and CKD by orthotopic liver transplantation, which attenuated proteinuria, kidney dysfunction, and fibrosis compared with control sham operated mice. Transcriptomic analysis of mouse kidney cortices revealed differentially expressed genes that were highly enriched in mitochondrial dysfunction, lipid metabolic process, and insulin signaling pathways in NASH-induced CKD. Lipidomic analysis of kidney cortices further revealed that phospholipids and sphingolipids were the most significantly changed lipid species. Notably, we found similar kidney histological changes in human NASH and CKD. Thus, our results confirm a causative role of NASH in the development of CKD, reveal potential pathophysiologic mechanisms of NASH-induced kidney injury, and established a valuable model to study the pathogenesis of NASH-associated CKD. This is an important feature of fatty liver disease that has been largely overlooked but has clinical and prognostic importance.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Insuficiência Renal Crônica , Humanos , Animais , Camundongos , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Modelos Animais de Doenças , Fibrose , Insuficiência Renal Crônica/patologia , Fosfolipídeos/metabolismo , Proteinúria/patologia , Fígado/patologia
13.
J Hepatol ; 80(2): 282-292, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37890720

RESUMO

BACKGROUND & AIMS: Chronic circadian dysfunction increases the risk of non-alcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC), but the underlying mechanisms and direct relevance to human HCC have not been established. In this study, we aimed to determine whether chronic circadian dysregulation can drive NAFLD-related carcinogenesis from human hepatocytes and human HCC progression. METHODS: Chronic jet lag of mice with humanized livers induces spontaneous NAFLD-related HCCs from human hepatocytes. The clinical relevance of this model was analysed by biomarker, pathological/histological, genetic, RNA sequencing, metabolomic, and integrated bioinformatic analyses. RESULTS: Circadian dysfunction induces glucose intolerance, NAFLD-associated human HCCs, and human HCC metastasis independent of diet in a humanized mouse model. The deregulated transcriptomes in necrotic-inflammatory humanized livers and HCCs bear a striking resemblance to those of human non-alcoholic steatohepatitis (NASH), cirrhosis, and HCC. Stable circadian entrainment of hosts rhythmically paces NASH and HCC transcriptomes to decrease HCC incidence and prevent HCC metastasis. Circadian disruption directly reprogrammes NASH and HCC transcriptomes to drive a rapid progression from hepatocarcinogenesis to HCC metastasis. Human hepatocyte and tumour transcripts are clearly distinguishable from mouse transcripts in non-parenchymal cells and tumour stroma, and display dynamic changes in metabolism, inflammation, angiogenesis, and oncogenic signalling in NASH, progressing to hepatocyte malignant transformation and immunosuppressive tumour stroma in HCCs. Metabolomic analysis defines specific bile acids as prognostic biomarkers that change dynamically during hepatocarcinogenesis and in response to circadian disruption at all disease stages. CONCLUSION: Chronic circadian dysfunction is independently carcinogenic to human hepatocytes. Mice with humanized livers provide a powerful preclinical model for studying the impact of the necrotic-inflammatory liver environment and neuroendocrine circadian dysfunction on hepatocarcinogenesis and anti-HCC therapy. IMPACT AND IMPLICATIONS: Human epidemiological studies have linked chronic circadian dysfunction to increased hepatocellular carcinoma (HCC) risk, but direct evidence that circadian dysfunction is a human carcinogen has not been established. Here we show that circadian dysfunction induces non-alcoholic steatohepatitis (NASH)-related carcinogenesis from human hepatocytes in a murine humanized liver model, following the same molecular and pathologic pathways observed in human patients. The gene expression signatures of humanized HCC transcriptomes from circadian-disrupted mice closely match those of human HCC with the poorest prognostic outcomes, while those from stably circadian entrained mice match those from human HCC with the best prognostic outcomes. Our studies establish a new model for defining the mechanism of NASH-related HCC and highlight the importance of circadian biology in HCC prevention and treatment.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , Animais , Camundongos , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/genética , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Fígado/patologia , Modelos Animais de Doenças , Carcinogênese/metabolismo , Carcinógenos/metabolismo
14.
EMBO J ; 39(22): e105604, 2020 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-33034091

RESUMO

Cooling patients to sub-physiological temperatures is an integral part of modern medicine. We show that cold exposure induces temperature-specific changes to the higher-order chromatin and gene expression profiles of human cells. These changes are particularly dramatic at 18°C, a temperature synonymous with that experienced by patients undergoing controlled deep hypothermia during surgery. Cells exposed to 18°C exhibit largely nuclear-restricted transcriptome changes. These include the nuclear accumulation of mRNAs encoding components of the negative limbs of the core circadian clock, most notably REV-ERBα. This response is accompanied by compaction of higher-order chromatin and hindrance of mRNPs from engaging nuclear pores. Rewarming reverses chromatin compaction and releases the transcripts into the cytoplasm, triggering a pulse of negative limb gene proteins that reset the circadian clock. We show that cold-induced upregulation of REV-ERBα is sufficient to trigger this reset. Our findings uncover principles of the cellular cold response that must be considered for current and future applications involving therapeutic deep hypothermia.


Assuntos
Núcleo Celular/metabolismo , Cromatina/metabolismo , Ritmo Circadiano/fisiologia , Temperatura Baixa , RNA Mensageiro/metabolismo , Linhagem Celular , Relógios Circadianos/genética , Relógios Circadianos/fisiologia , Ritmo Circadiano/genética , Técnicas de Inativação de Genes , Heterocromatina , Humanos , Hipotermia/cirurgia , Ativação Transcricional , Transcriptoma , Regulação para Cima
15.
J Mol Evol ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844681

RESUMO

Genome size variation in eukaryotes has myriad effects on organismal biology from the genomic to whole-organism level. Large genome size may be associated with lower selection efficiency because lower effective population sizes allow fixation of deleterious mutations via genetic drift, increasing genome size and decreasing selection efficiency. Because of a hypothesized negative relationship between genome size and recombination rate per base pair, increased genome size could also increase the effect of linked selection in the genome, decreasing the efficiency with which natural selection can fix or remove mutations. We used a transcriptomic dataset of 15 and a subset of six Neotropical salamander species ranging in genome size from 12 to 87 pg to study the relationship between genome size and efficiency of selection. We estimated dN/dS of salamanders with small and large genomes and tested for relaxation of selection in the larger genomes. Contrary to our expectations, we did not find a significant relationship between genome size and selection efficiency or strong evidence for higher dN/dS values in species with larger genomes for either species set. We also found little evidence for relaxation of selection in species with larger genomes. A positive correlation between genome size and range size (a proxy of population size) in this group disagrees with predictions of stronger drift in species with larger genomes. Our results highlight the complex interactions between the many forces shaping genomic variation in organisms with genomic gigantism.

16.
Brief Bioinform ; 23(2)2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35048121

RESUMO

Advancement in single-cell RNA sequencing leads to exponential accumulation of single-cell expression data. However, there is still lack of tools that could integrate these unlimited accumulations of single-cell expression data. Here, we presented a universal approach iSEEEK for integrating super large-scale single-cell expression via exploring expression rankings of top-expressing genes. We developed iSEEEK with 11.9 million single cells. We demonstrated the efficiency of iSEEEK with canonical single-cell downstream tasks on five heterogenous datasets encompassing human and mouse samples. iSEEEK achieved good clustering performance benchmarked against well-annotated cell labels. In addition, iSEEEK could transfer its knowledge learned from large-scale expression data on new dataset that was not involved in its development. iSEEEK enables identification of gene-gene interaction networks that are characteristic of specific cell types. Our study presents a simple and yet effective method to integrate super large-scale single-cell transcriptomes and would facilitate translational single-cell research from bench to bedside.


Assuntos
Análise de Célula Única , Transcriptoma , Animais , Análise por Conglomerados , Redes Reguladoras de Genes , Camundongos , Análise de Célula Única/métodos , Sequenciamento do Exoma
17.
Mol Phylogenet Evol ; 191: 107991, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38092322

RESUMO

Anaerobes have emerged in several major lineages of ciliates, but the number of independent transitions to anaerobiosis among ciliates is unknown. The APM clade (Armophorea, Muranotrichea, Parablepharismea) represents the largest clade of obligate anaerobes among ciliates and contains free-living marine and freshwater representatives as well as gut endobionts of animals. The evolution of APM group has only recently started getting attention, and our knowledge on its phylogeny and genetics is still limited to a fraction of taxa. While ciliates portray a wide array of alternatives to the standard genetic code across numerous classes, the APM ciliates were considered to be the largest group using exclusively standard nuclear genetic code. In this study, we present a pan-ciliate phylogenomic analysis with emphasis on the APM clade, bringing the first phylogenomic analysis of the family Tropidoatractidae (Armophorea) and confirming the position of Armophorida within Armophorea. We include five newly sequenced single cell transcriptomes from marine, freshwater, and endobiotic APM ciliates - Palmarella salina, Anteclevelandella constricta, Nyctotherus sp., Caenomorpha medusula, and Thigmothrix strigosa. We report the first discovery of an alternative nuclear genetic code among APM ciliates, used by Palmarella salina (Tropidoatractidae, Armophorea), but not by its close relative, Tropidoatractus sp., and provide a comparative analysis of stop codon identity and frequency indicating the precedency to the UAG codon loss/reassignment over the UAA codon reassignment in the specific ancestor of Palmarella. Comparative genomic and proteomic studies of this group may help explain the constraints that underlie UAR stop-to-sense reassignment, the most frequent type of alternative nuclear genetic code, not only in ciliates, but eukaryotes in general.


Assuntos
Cilióforos , Proteômica , Animais , Filogenia , Código Genético , Cilióforos/genética , Códon de Terminação , Perfilação da Expressão Gênica
18.
J Nutr ; 154(2): 354-368, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38065409

RESUMO

BACKGROUND: The processes of tumor growth and circadian rhythm are intimately intertwined; thus, rewiring circadian metabolism by time-restricted feeding (TRF) may contribute to delaying carcinogenesis. However, research on the effect of a TRF cellular regimen on cancer is lacking. OBJECTIVE: Investigate the circadian signatures of TRF in lung cancer in vitro. METHODS: We first developed a cellular paradigm mimicking in vivo TRF and collected cells for transcriptome analysis. We further confirmed the effect on tumor cells upon 6-h TRF-mimicking (6-h TRFM) by real-time PCR, Lumicycle experiments, CCK-8, and flow cytometry assays. RESULTS: We found that A549 lung adenocarcinoma cells treated with 6-h TRFM conditions displayed robust diurnal rhythms of transcriptomes, as well as modulation of the core clock genes relative to other different cellular regimens used in this study, including the fasting-mimicking conditions (ie, short-term starvation) and the serum-free regime. Notably, pathway analysis of oscillating genes exclusively in 6-h TRFM showed that some circadian genes were enriched in tumor-related pathways, such as the oxytocin signaling pathway, HIF-1 signaling pathway, and pentose and glucuronate interconversions. Moreover, in line with the circadian pathway enrichment results, 6-h TRFM robustly inhibited cell proliferation and induced cell apoptosis and cell cycle arrest in lung adenocarcinoma A549 cells, lung adenocarcinoma H460 cells, esophageal carcinoma Eca-109 cells, and breast adenocarcinoma MCF-7 cells. CONCLUSIONS: Our findings provide the first in vitro mimicking medium for TRF intervention and indicate that 6-h TRFM is sufficient to reprogram the circadian signatures of lung adenocarcinoma cells and inhibit the progression of multiple tumors.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Transcriptoma , Jejum , Ritmo Circadiano/genética , Adenocarcinoma de Pulmão/genética , Neoplasias Pulmonares/genética
19.
Microb Ecol ; 87(1): 73, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38758374

RESUMO

Endophytes generally increase antioxidant contents of plants subjected to environmental stresses. However, the mechanisms by which endophytes alter the accumulation of antioxidants in plant tissues are not entirely clear. We hypothesized that, in stress situations, endophytes would simultaneously reduce oxidative damage and increase antioxidant contents of plants and that the accumulation of antioxidants would be a consequence of the endophyte ability to regulate the expression of plant antioxidant genes. We investigated the effects of the fungal endophyte Epichloë gansuensis (C.J. Li & Nan) on oxidative damage, antioxidant contents, and expression of representative genes associated with antioxidant pathways in Achnatherum inebrians (Hance) Keng plants subjected to low (15%) and high (60%) soil moisture conditions. Gene expression levels were measured using RNA-seq. As expected, the endophyte reduced the oxidative damage by 17.55% and increased the antioxidant contents by 53.14% (on average) in plants subjected to low soil moisture. In line with the accumulation of antioxidants in plant tissues, the endophyte increased the expression of most plant genes associated with the biosynthesis of antioxidants (e.g., MIOX, crtB, gpx) while it reduced the expression of plant genes related to the metabolization of antioxidants (e.g., GST, PRODH, ALDH). Our findings suggest that endophyte ability of increasing antioxidant contents in plants may reduce the oxidative damage caused by stresses and that the fungal regulation of plant antioxidants would partly explain the accumulation of these compounds in plant tissues.


Assuntos
Antioxidantes , Secas , Endófitos , Epichloe , Estresse Oxidativo , Endófitos/metabolismo , Endófitos/fisiologia , Antioxidantes/metabolismo , Epichloe/fisiologia , Epichloe/genética , Epichloe/metabolismo , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico
20.
J Pept Sci ; 30(4): e3554, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38009400

RESUMO

The cysteine-free acyclic peptides present in marine cone snail venom have been much less investigated than their disulfide bonded counterparts. Precursor protein sequences derived from transcriptomic data, together with mass spectrometric fragmentation patterns for peptides present in venom duct tissue extracts, permit the identification of mature peptides. Twelve distinct gene superfamiles have been identified with precursor lengths between 64 and 158 residues. In the case of Conus monile, three distinct mature peptides have been identified, arising from two distinct protein precursors. Mature acyclic peptides are often post-translationally modified, with C-terminus amidation, a feature characteristic of neuropeptides. In the present study, 20 acyclic peptides from Conus monile and Conus betulinus were identified. The common modifications of C-terminus amidation, gamma carboxylation of glutamic acid (E to ϒ), N-terminus conversion of Gln (Q) to a pyroglutamyl residue (Z), and hydroxylation of Pro (P) to Hyp (O) are observed in one or more peptides identified in this study. Proteolytic trimming of sequences by cleavage at the C-terminus of Asn (N) residues is established. The presence of an asparagine endopeptidase is strengthened by the identification of legumain-like sequences in the transcriptome assemblies from diverse Conus species. Such sequences may be expected to have a cleavage specificity at Asn-Xxx peptide bonds.


Assuntos
Conotoxinas , Caramujo Conus , Animais , Venenos de Moluscos/química , Venenos de Moluscos/genética , Venenos de Moluscos/metabolismo , Conotoxinas/química , Peptídeos/química , Caramujo Conus/química , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo
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