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1.
Cell ; 179(7): 1609-1622.e16, 2019 12 12.
Artículo en Inglés | MEDLINE | ID: mdl-31835035

RESUMEN

Microglia, the brain-resident immune cells, are critically involved in many physiological and pathological brain processes, including neurodegeneration. Here we characterize microglia morphology and transcriptional programs across ten species spanning more than 450 million years of evolution. We find that microglia express a conserved core gene program of orthologous genes from rodents to humans, including ligands and receptors associated with interactions between glia and neurons. In most species, microglia show a single dominant transcriptional state, whereas human microglia display significant heterogeneity. In addition, we observed notable differences in several gene modules of rodents compared with primate microglia, including complement, phagocytic, and susceptibility genes to neurodegeneration, such as Alzheimer's and Parkinson's disease. Our study provides an essential resource of conserved and divergent microglia pathways across evolution, with important implications for future development of microglia-based therapies in humans.


Asunto(s)
Evolución Molecular , Redes Reguladoras de Genes , Microglía/metabolismo , Enfermedades Neurodegenerativas/genética , Análisis de la Célula Individual , Transcriptoma , Animales , Pollos , Perfilación de la Expresión Génica , Predisposición Genética a la Enfermedad , Humanos , Primates , Reptiles , Roedores , Ovinos , Porcinos , Pez Cebra
2.
Cell ; 165(6): 1310-1311, 2016 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-27259141

RESUMEN

The drive to sleep increases the longer that we stay awake, but this process is poorly understood at the cellular level. Now, Liu et al. show that the plasticity of a small group of neurons in the Drosophila central brain is a key component of the sleep homeostat.


Asunto(s)
Drosophila melanogaster/metabolismo , Receptores de N-Metil-D-Aspartato , Animales , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Ovinos , Sueño
3.
Immunity ; 54(5): 988-1001.e5, 2021 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-33857421

RESUMEN

Positive selection of high-affinity B cells within germinal centers (GCs) drives affinity maturation of antibody responses. Here, we examined the mechanism underlying the parallel transition from immunoglobulin M (IgM) to IgG. Early GCs contained mostly unswitched IgM+ B cells; IgG+ B cells subsequently increased in frequency, dominating GC responses 14-21 days after antigen challenge. Somatic hypermutation and generation of high-affinity clones occurred with equal efficiency among IgM+ and IgG+ GC B cells, and inactivation of Ig class-switch recombination did not prevent depletion of IgM+ GC B cells. Instead, high-affinity IgG+ GC B cells outcompeted high-affinity IgM+ GC B cells via a selective advantage associated with IgG antigen receptor structure but independent of the extended cytoplasmic tail. Thus, two parallel forms of GC B-cell-positive selection, based on antigen receptor variable and constant regions, respectively, operate in tandem to ensure high-affinity IgG antibodies predominate in mature serum antibody responses.


Asunto(s)
Linfocitos B/inmunología , Centro Germinal/inmunología , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Animales , Formación de Anticuerpos/inmunología , Antígenos/inmunología , Femenino , Cambio de Clase de Inmunoglobulina/inmunología , Región Variable de Inmunoglobulina/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Ovinos/inmunología , Hipermutación Somática de Inmunoglobulina/inmunología
4.
Nature ; 623(7989): 1034-1043, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37993715

RESUMEN

Diet-derived nutrients are inextricably linked to human physiology by providing energy and biosynthetic building blocks and by functioning as regulatory molecules. However, the mechanisms by which circulating nutrients in the human body influence specific physiological processes remain largely unknown. Here we use a blood nutrient compound library-based screening approach to demonstrate that dietary trans-vaccenic acid (TVA) directly promotes effector CD8+ T cell function and anti-tumour immunity in vivo. TVA is the predominant form of trans-fatty acids enriched in human milk, but the human body cannot produce TVA endogenously1. Circulating TVA in humans is mainly from ruminant-derived foods including beef, lamb and dairy products such as milk and butter2,3, but only around 19% or 12% of dietary TVA is converted to rumenic acid by humans or mice, respectively4,5. Mechanistically, TVA inactivates the cell-surface receptor GPR43, an immunomodulatory G protein-coupled receptor activated by its short-chain fatty acid ligands6-8. TVA thus antagonizes the short-chain fatty acid agonists of GPR43, leading to activation of the cAMP-PKA-CREB axis for enhanced CD8+ T cell function. These findings reveal that diet-derived TVA represents a mechanism for host-extrinsic reprogramming of CD8+ T cells as opposed to the intrahost gut microbiota-derived short-chain fatty acids. TVA thus has translational potential for the treatment of tumours.


Asunto(s)
Linfocitos T CD8-positivos , Neoplasias , Ácidos Oléicos , Animales , Bovinos , Humanos , Ratones , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , AMP Cíclico/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Productos Lácteos , Ácidos Grasos Volátiles/farmacología , Ácidos Grasos Volátiles/uso terapéutico , Leche/química , Neoplasias/dietoterapia , Neoplasias/inmunología , Ácidos Oléicos/farmacología , Ácidos Oléicos/uso terapéutico , Carne Roja , Ovinos
5.
Annu Rev Genet ; 53: 117-147, 2019 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-31537104

RESUMEN

Mammalian prion diseases are a group of neurodegenerative conditions caused by infection of the central nervous system with proteinaceous agents called prions, including sporadic, variant, and iatrogenic Creutzfeldt-Jakob disease; kuru; inherited prion disease; sheep scrapie; bovine spongiform encephalopathy; and chronic wasting disease. Prions are composed of misfolded and multimeric forms of the normal cellular prion protein (PrP). Prion diseases require host expression of the prion protein gene (PRNP) and a range of other cellular functions to support their propagation and toxicity. Inherited forms of prion disease are caused by mutation of PRNP, whereas acquired and sporadically occurring mammalian prion diseases are controlled by powerful genetic risk and modifying factors. Whereas some PrP amino acid variants cause the disease, others confer protection, dramatically altered incubation times, or changes in the clinical phenotype. Multiple mechanisms, including interference with homotypic protein interactions and the selection of the permissible prion strains in a host, play a role. Several non-PRNP factors have now been uncovered that provide insights into pathways of disease susceptibility or neurotoxicity.


Asunto(s)
Mamíferos/genética , Enfermedades por Prión/genética , Proteínas Priónicas/genética , Animales , Bovinos , Modelos Animales de Enfermedad , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Pruebas Genéticas , Cabras/genética , Humanos , Ratones , Polimorfismo Genético , Enfermedades por Prión/etiología , Proteínas Priónicas/metabolismo , Selección Genética , Ovinos/genética
6.
Nat Immunol ; 16(4): 415-25, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25706746

RESUMEN

Post-transcriptional regulation of mRNA by the RNA-binding protein HuR (encoded by Elavl1) is required in B cells for the germinal center reaction and for the production of class-switched antibodies in response to thymus-independent antigens. Transcriptome-wide examination of RNA isoforms and their abundance and translation in HuR-deficient B cells, together with direct measurements of HuR-RNA interactions, revealed that HuR-dependent splicing of mRNA affected hundreds of transcripts, including that encoding dihydrolipoamide S-succinyltransferase (Dlst), a subunit of the 2-oxoglutarate dehydrogenase (α-KGDH) complex. In the absence of HuR, defective mitochondrial metabolism resulted in large amounts of reactive oxygen species and B cell death. Our study shows how post-transcriptional processes control the balance of energy metabolism required for the proliferation and differentiation of B cells.


Asunto(s)
Linfocitos B/inmunología , Proteínas ELAV/inmunología , Centro Germinal/inmunología , Inmunidad Humoral , Inmunoglobulinas/biosíntesis , ARN Mensajero/inmunología , Aciltransferasas/genética , Aciltransferasas/inmunología , Empalme Alternativo/inmunología , Animales , Antígenos/administración & dosificación , Antígenos/inmunología , Linfocitos B/citología , Linfocitos B/efectos de los fármacos , Muerte Celular , Diferenciación Celular , Proliferación Celular , Proteínas ELAV/genética , Eritrocitos/inmunología , Centro Germinal/citología , Centro Germinal/efectos de los fármacos , Inmunización , Cambio de Clase de Inmunoglobulina , Lipopolisacáridos/farmacología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/genética , Mitocondrias/inmunología , ARN Mensajero/genética , Especies Reactivas de Oxígeno/inmunología , Especies Reactivas de Oxígeno/metabolismo , Ovinos
7.
Nature ; 598(7880): 364-367, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34616041

RESUMEN

The enzymes of the mitochondrial electron transport chain are key players of cell metabolism. Despite being active when isolated, in vivo they associate into supercomplexes1, whose precise role is debated. Supercomplexes CIII2CIV1-2 (refs. 2,3), CICIII2 (ref. 4) and CICIII2CIV (respirasome)5-10 exist in mammals, but in contrast to CICIII2 and the respirasome, to date the only known eukaryotic structures of CIII2CIV1-2 come from Saccharomyces cerevisiae11,12 and plants13, which have different organization. Here we present the first, to our knowledge, structures of mammalian (mouse and ovine) CIII2CIV and its assembly intermediates, in different conformations. We describe the assembly of CIII2CIV from the CIII2 precursor to the final CIII2CIV conformation, driven by the insertion of the N terminus of the assembly factor SCAF1 (ref. 14) deep into CIII2, while its C terminus is integrated into CIV. Our structures (which include CICIII2 and the respirasome) also confirm that SCAF1 is exclusively required for the assembly of CIII2CIV and has no role in the assembly of the respirasome. We show that CIII2 is asymmetric due to the presence of only one copy of subunit 9, which straddles both monomers and prevents the attachment of a second copy of SCAF1 to CIII2, explaining the presence of one copy of CIV in CIII2CIV in mammals. Finally, we show that CIII2 and CIV gain catalytic advantage when assembled into the supercomplex and propose a role for CIII2CIV in fine tuning the efficiency of electron transfer in the electron transport chain.


Asunto(s)
Respiración de la Célula , Mitocondrias/enzimología , Complejos Multienzimáticos/química , Complejos Multienzimáticos/metabolismo , Ovinos , Animales , Sitios de Unión , Conjuntos de Datos como Asunto , Transporte de Electrón , Ratones , Mitocondrias/metabolismo , Modelos Moleculares , NAD/metabolismo , Ácido Succínico/metabolismo
8.
Nature ; 599(7884): 256-261, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34707286

RESUMEN

The identity of the earliest inhabitants of Xinjiang, in the heart of Inner Asia, and the languages that they spoke have long been debated and remain contentious1. Here we present genomic data from 5 individuals dating to around 3000-2800 BC from the Dzungarian Basin and 13 individuals dating to around 2100-1700 BC from the Tarim Basin, representing the earliest yet discovered human remains from North and South Xinjiang, respectively. We find that the Early Bronze Age Dzungarian individuals exhibit a predominantly Afanasievo ancestry with an additional local contribution, and the Early-Middle Bronze Age Tarim individuals contain only a local ancestry. The Tarim individuals from the site of Xiaohe further exhibit strong evidence of milk proteins in their dental calculus, indicating a reliance on dairy pastoralism at the site since its founding. Our results do not support previous hypotheses for the origin of the Tarim mummies, who were argued to be Proto-Tocharian-speaking pastoralists descended from the Afanasievo1,2 or to have originated among the Bactria-Margiana Archaeological Complex3 or Inner Asian Mountain Corridor cultures4. Instead, although Tocharian may have been plausibly introduced to the Dzungarian Basin by Afanasievo migrants during the Early Bronze Age, we find that the earliest Tarim Basin cultures appear to have arisen from a genetically isolated local population that adopted neighbouring pastoralist and agriculturalist practices, which allowed them to settle and thrive along the shifting riverine oases of the Taklamakan Desert.


Asunto(s)
Arqueología , Genoma Humano/genética , Genómica , Migración Humana/historia , Momias/historia , Filogenia , Agricultura/historia , Animales , Bovinos , China , Características Culturales , Cálculos Dentales/química , Clima Desértico , Dieta/historia , Europa (Continente) , Femenino , Cabras , Pradera , Historia Antigua , Humanos , Masculino , Proteínas de la Leche/análisis , Filogeografía , Análisis de Componente Principal , Proteoma/análisis , Proteómica , Ovinos , Secuenciación Completa del Genoma
9.
Mol Cell ; 75(6): 1131-1146.e6, 2019 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-31492636

RESUMEN

The mitochondrial electron transport chain complexes are organized into supercomplexes (SCs) of defined stoichiometry, which have been proposed to regulate electron flux via substrate channeling. We demonstrate that CoQ trapping in the isolated SC I+III2 limits complex (C)I turnover, arguing against channeling. The SC structure, resolved at up to 3.8 Å in four distinct states, suggests that CoQ oxidation may be rate limiting because of unequal access of CoQ to the active sites of CIII2. CI shows a transition between "closed" and "open" conformations, accompanied by the striking rotation of a key transmembrane helix. Furthermore, the state of CI affects the conformational flexibility within CIII2, demonstrating crosstalk between the enzymes. CoQ was identified at only three of the four binding sites in CIII2, suggesting that interaction with CI disrupts CIII2 symmetry in a functionally relevant manner. Together, these observations indicate a more nuanced functional role for the SCs.


Asunto(s)
Complejo III de Transporte de Electrones/química , Complejo I de Transporte de Electrón/química , Mitocondrias Cardíacas/enzimología , Animales , Cristalografía por Rayos X , Estructura Cuaternaria de Proteína , Ovinos
10.
Proc Natl Acad Sci U S A ; 121(27): e2322291121, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38913905

RESUMEN

Tibetan sheep were introduced to the Qinghai Tibet plateau roughly 3,000 B.P., making this species a good model for investigating genetic mechanisms of high-altitude adaptation over a relatively short timescale. Here, we characterize genomic structural variants (SVs) that distinguish Tibetan sheep from closely related, low-altitude Hu sheep, and we examine associated changes in tissue-specific gene expression. We document differentiation between the two sheep breeds in frequencies of SVs associated with genes involved in cardiac function and circulation. In Tibetan sheep, we identified high-frequency SVs in a total of 462 genes, including EPAS1, PAPSS2, and PTPRD. Single-cell RNA-Seq data and luciferase reporter assays revealed that the SVs had cis-acting effects on the expression levels of these three genes in specific tissues and cell types. In Tibetan sheep, we identified a high-frequency chromosomal inversion that exhibited modified chromatin architectures relative to the noninverted allele that predominates in Hu sheep. The inversion harbors several genes with altered expression patterns related to heart protection, brown adipocyte proliferation, angiogenesis, and DNA repair. These findings indicate that SVs represent an important source of genetic variation in gene expression and may have contributed to high-altitude adaptation in Tibetan sheep.


Asunto(s)
Altitud , Animales , Ovinos/genética , Tibet , Variación Estructural del Genoma , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Regulación de la Expresión Génica , Genoma , Aclimatación/genética
11.
EMBO J ; 41(23): e112338, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36254605

RESUMEN

A defining characteristic of mammalian prions is their capacity for self-sustained propagation. Theoretical considerations and experimental evidence suggest that prion propagation is modulated by cell-autonomous and non-autonomous modifiers. Using a novel quantitative phospholipase protection assay (QUIPPER) for high-throughput prion measurements, we performed an arrayed genome-wide RNA interference (RNAi) screen aimed at detecting cellular host-factors that can modify prion propagation. We exposed prion-infected cells in high-density microplates to 35,364 ternary pools of 52,746 siRNAs targeting 17,582 genes representing the majority of the mouse protein-coding transcriptome. We identified 1,191 modulators of prion propagation. While 1,151 modified the expression of both the pathological prion protein, PrPSc , and its cellular counterpart, PrPC , 40 genes selectively affected PrPSc . Of the latter 40 genes, 20 augmented prion production when suppressed. A prominent limiter of prion propagation was the heterogeneous nuclear ribonucleoprotein Hnrnpk. Psammaplysene A (PSA), which binds Hnrnpk, reduced prion levels in cultured cells and protected them from cytotoxicity. PSA also reduced prion levels in infected cerebellar organotypic slices and alleviated locomotor deficits in prion-infected Drosophila melanogaster expressing ovine PrPC . Hence, genome-wide QUIPPER-based perturbations can discover actionable cellular pathways involved in prion propagation. Further, the unexpected identification of a prion-controlling ribonucleoprotein suggests a role for RNA in the generation of infectious prions.


Asunto(s)
Enfermedades por Prión , Priones , Ratones , Animales , Ovinos/genética , Priones/genética , Priones/metabolismo , Drosophila melanogaster/genética , Ribonucleoproteínas/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Enfermedades por Prión/genética , Enfermedades por Prión/patología , Mamíferos/genética
12.
J Cell Sci ; 137(7)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38606789

RESUMEN

Robertsonian chromosomes form by fusion of two chromosomes that have centromeres located near their ends, known as acrocentric or telocentric chromosomes. This fusion creates a new metacentric chromosome and is a major mechanism of karyotype evolution and speciation. Robertsonian chromosomes are common in nature and were first described in grasshoppers by the zoologist W. R. B. Robertson more than 100 years ago. They have since been observed in many species, including catfish, sheep, butterflies, bats, bovids, rodents and humans, and are the most common chromosomal change in mammals. Robertsonian translocations are particularly rampant in the house mouse, Mus musculus domesticus, where they exhibit meiotic drive and create reproductive isolation. Recent progress has been made in understanding how Robertsonian chromosomes form in the human genome, highlighting some of the fundamental principles of how and why these types of fusion events occur so frequently. Consequences of these fusions include infertility and Down's syndrome. In this Hypothesis, I postulate that the conditions that allow these fusions to form are threefold: (1) sequence homology on non-homologous chromosomes, often in the form of repetitive DNA; (2) recombination initiation during meiosis; and (3) physical proximity of the homologous sequences in three-dimensional space. This Hypothesis highlights the latest progress in understanding human Robertsonian translocations within the context of the broader literature on Robertsonian chromosomes.


Asunto(s)
Mariposas Diurnas , Ratones , Humanos , Animales , Ovinos/genética , Mariposas Diurnas/genética , Cromosomas/genética , Meiosis/genética , Centrómero , Translocación Genética/genética , Mamíferos
13.
Genome Res ; 33(3): 463-477, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-37310928

RESUMEN

Structural variations (SVs) are a major contributor to genetic diversity and phenotypic variations, but their prevalence and functions in domestic animals are largely unexplored. Here we generated high-quality genome assemblies for 15 individuals from genetically diverse sheep breeds using Pacific Biosciences (PacBio) high-fidelity sequencing, discovering 130.3 Mb nonreference sequences, from which 588 genes were annotated. A total of 149,158 biallelic insertions/deletions, 6531 divergent alleles, and 14,707 multiallelic variations with precise breakpoints were discovered. The SV spectrum is characterized by an excess of derived insertions compared to deletions (94,422 vs. 33,571), suggesting recent active LINE expansions in sheep. Nearly half of the SVs display low to moderate linkage disequilibrium with surrounding single-nucleotide polymorphisms (SNPs) and most SVs cannot be tagged by SNP probes from the widely used ovine 50K SNP chip. We identified 865 population-stratified SVs including 122 SVs possibly derived in the domestication process among 690 individuals from sheep breeds worldwide. A novel 168-bp insertion in the 5' untranslated region (5' UTR) of HOXB13 is found at high frequency in long-tailed sheep. Further genome-wide association study and gene expression analyses suggest that this mutation is causative for the long-tail trait. In summary, we have developed a panel of high-quality de novo assemblies and present a catalog of structural variations in sheep. Our data capture abundant candidate functional variations that were previously unexplored and provide a fundamental resource for understanding trait biology in sheep.


Asunto(s)
Estudio de Asociación del Genoma Completo , Cola (estructura animal) , Animales , Ovinos/genética , Regiones no Traducidas 5' , Alelos , Fenotipo
14.
Genome Res ; 33(10): 1690-1707, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37884341

RESUMEN

The rumen undergoes developmental changes during maturation. To characterize this understudied dynamic process, we profiled single-cell transcriptomes of about 308,000 cells from the rumen tissues of sheep and goats at 17 time points. We built comprehensive transcriptome and metagenome atlases from early embryonic to rumination stages, and recapitulated histomorphometric and transcriptional features of the rumen, revealing key transitional signatures associated with the development of ruminal cells, microbiota, and core transcriptional regulatory networks. In addition, we identified and validated potential cross-talk between host cells and microbiomes and revealed their roles in modulating the spatiotemporal expression of key genes in ruminal cells. Cross-species analyses revealed convergent developmental patterns of cellular heterogeneity, gene expression, and cell-cell and microbiome-cell interactions. Finally, we uncovered how the interactions can act upon the symbiotic rumen system to modify the processes of fermentation, fiber digestion, and immune defense. These results significantly enhance understanding of the genetic basis of the unique roles of rumen.


Asunto(s)
Metagenoma , Microbiota , Ovinos/genética , Animales , Transcriptoma , Rumen , Rumiantes/genética
15.
PLoS Pathog ; 20(1): e1011908, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38198498

RESUMEN

Macroecological approaches can provide valuable insight into the epidemiology of globally distributed, multi-host pathogens. Toxoplasma gondii is a protozoan that infects any warm-blooded animal, including humans, in almost every habitat worldwide. Toxoplasma gondii infects its hosts through oocysts in the environment, carnivory of tissue cysts within intermediate host prey and vertical transmission. These routes of infection enable specific predictions regarding the ecological and life history traits that should predispose specific taxa to higher exposure and, thus infection rates of T. gondii. Using T. gondii prevalence data compiled from 485 studies representing 533 free-ranging wild mammalian species, we examined how ecological (habitat type, trophic level) and life history (longevity, vagility, gestation duration and torpor) traits influence T. gondii infection globally. We also compared T. gondii prevalence between wild and domesticated species from the same taxonomic families using data compiled from 540 studies of domestic cattle, sheep, and pigs. Across free-ranging wildlife, we found the average T. gondii prevalence was 22%, which is comparable to the global human estimate. Among ecological guilds, terrestrial species had lower T. gondii prevalence than aquatic species, with freshwater aquatic taxa having an increased prevalence compared to marine aquatic species. Dietary niches were also influential, with carnivores having an increased risk compared to other trophic feeding groups that have reduced tissue cyst exposure in their diet. With respect to influential life history traits, we found that more vagile wildlife species had higher T. gondii infection rates, perhaps because of the higher cumulative risk of infection during movement through areas with varying T. gondii environmental loads. Domestic farmed species had a higher T. gondii prevalence compared to free-ranging confamilial wildlife species. Through a macroecological approach, we determined the relative significance of transmission routes of a generalist pathogen, demonstrating an increased infection risk for aquatic and carnivorous species and highlighting the importance of preventing pathogen pollution into aquatic environments. Toxoplasma gondii is increasingly understood to be primarily an anthropogenically-associated pathogen whose dissemination is enhanced by ecosystem degradation and human subsidisation of free-roaming domestic cats. Adopting an ecosystem restoration approach to reduce one of the world's most common parasites would synergistically contribute to other initiatives in conservation, feline and wildlife welfare, climate change, food security and public health.


Asunto(s)
Toxoplasma , Toxoplasmosis Animal , Animales , Gatos , Bovinos , Animales Salvajes , Ecosistema , Mamíferos , Prevalencia , Ovinos , Porcinos , Toxoplasmosis Animal/epidemiología , Toxoplasmosis Animal/parasitología
16.
J Immunol ; 212(4): 689-701, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38149922

RESUMEN

The classical pathway (CP) is a potent mechanism for initiating complement activity and is a driver of pathology in many complement-mediated diseases. The CP is initiated via activation of complement component C1, which consists of the pattern recognition molecule C1q bound to a tetrameric assembly of proteases C1r and C1s. Enzymatically active C1s provides the catalytic basis for cleavage of the downstream CP components, C4 and C2, and is therefore an attractive target for therapeutic intervention in CP-driven diseases. Although an anti-C1s mAb has been Food and Drug Administration approved, identifying small-molecule C1s inhibitors remains a priority. In this study, we describe 6-(4-phenylpiperazin-1-yl)pyridine-3-carboximidamide (A1) as a selective, competitive inhibitor of C1s. A1 was identified through a virtual screen for small molecules that interact with the C1s substrate recognition site. Subsequent functional studies revealed that A1 dose-dependently inhibits CP activation by heparin-induced immune complexes, CP-driven lysis of Ab-sensitized sheep erythrocytes, CP activation in a pathway-specific ELISA, and cleavage of C2 by C1s. Biochemical experiments demonstrated that A1 binds directly to C1s with a Kd of ∼9.8 µM and competitively inhibits its activity with an inhibition constant (Ki) of ∼5.8 µM. A 1.8-Å-resolution crystal structure revealed the physical basis for C1s inhibition by A1 and provided information on the structure-activity relationship of the A1 scaffold, which was supported by evaluating a panel of A1 analogs. Taken together, our work identifies A1 as a new class of small-molecule C1s inhibitor and lays the foundation for development of increasingly potent and selective A1 analogs for both research and therapeutic purposes.


Asunto(s)
Complemento C1s , Vía Clásica del Complemento , Animales , Ovinos , Péptido Hidrolasas , Complemento C1/metabolismo , Endopeptidasas , Piridinas/farmacología
17.
PLoS Genet ; 19(2): e1010615, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36821549

RESUMEN

The worldwide sheep population comprises more than 1000 breeds. Together, these exhibit a considerable morphological diversity, which has not been extensively investigated at the molecular level. Here, we analyze whole-genome sequencing individuals of 1,098 domestic sheep from 154 breeds, and 69 wild sheep from seven Ovis species. On average, we detected 6.8%, 1.0% and 0.2% introgressed sequence in domestic sheep originating from Iranian mouflon, urial and argali, respectively, with rare introgressions from other wild species. Interestingly, several introgressed haplotypes contributed to the morphological differentiations across sheep breeds, such as a RXFP2 haplotype from Iranian mouflon conferring the spiral horn trait, a MSRB3 haplotype from argali strongly associated with ear morphology, and a VPS13B haplotype probably originating from urial and mouflon possibly associated with facial traits. Our results reveal that introgression events from wild Ovis species contributed to the high rate of morphological differentiation in sheep breeds, but also to individual variation within breeds. We propose that long divergent haplotypes are a ubiquitous source of phenotypic variation that allows adaptation to a variable environment, and that these remain intact in the receiving population probably due to reduced recombination.


Asunto(s)
Aclimatación , Oveja Doméstica , Ovinos/genética , Animales , Oveja Doméstica/genética , Haplotipos/genética , Irán , Fenotipo
18.
Dev Biol ; 506: 64-71, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38081502

RESUMEN

INTRODUCTION: After birth, the lungs must resorb the fluid they contain. This process involves multiple actors such as surfactant, aquaporins and ENaC channels. Preterm newborns often exhibit respiratory distress syndrome due to surfactant deficiency, and transitory tachypnea caused by a delay in lung liquid resorption. Our hypothesis is that surfactant, ENaC and aquaporins are involved in respiratory transition to extrauterine life and altered by preterm birth. We compared these candidates in preterm and term fetal sheeps. MATERIALS AND METHODS: We performed cesarean sections in 8 time-dated pregnant ewes (4 at 100 days and 4 at 140 days of gestation, corresponding to 24 and 36 weeks of gestation in humans), and obtained 13 fetal sheeps in each group. We studied surfactant synthesis (SP-A, SP-B, SP-C), lung liquid resorption (ENaC, aquaporins) and corticosteroid regulation (glucocorticoid receptor, mineralocorticoid receptor and 11-betaHSD2) at mRNA and protein levels. RESULTS: The mRNA expression level of SFTPA, SFTPB and SFTPC was higher in the term group. These results were confirmed at the protein level for SP-B on Western Blot analysis and for SP-A, SP-B and SP-C on immunohistochemical analysis. Regarding aquaporins, ENaC and receptors, mRNA expression levels for AQP1, AQP3, AQP5, ENaCα, ENaCß, ENaCγ and 11ßHSD2 mRNA were also higher in the term group. DISCUSSION: Expression of surfactant proteins, aquaporins and ENaC increases between 100 and 140 days of gestation in an ovine model. Further exploring these pathways and their hormonal regulation could highlight some new explanations in the pathophysiology of neonatal respiratory diseases.


Asunto(s)
Acuaporinas , Nacimiento Prematuro , Embarazo , Humanos , Animales , Ovinos , Femenino , Tensoactivos/metabolismo , Nacimiento Prematuro/metabolismo , Pulmón/metabolismo , Acuaporinas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo
19.
Mol Biol Evol ; 41(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38552245

RESUMEN

Domestication and artificial selection during production-oriented breeding have greatly shaped the level of genomic variability in sheep. However, the genetic variation associated with increased reproduction remains elusive. Here, two groups of samples from consecutively monotocous and polytocous sheep were collected for genome-wide association, transcriptomic, proteomic, and metabolomic analyses to explore the genetic variation in fecundity in Tibetan sheep. Genome-wide association study revealed strong associations between BMPR1B (p.Q249R) and litter size, as well as between PAPPA and lambing interval; these findings were validated in 1,130 individuals. Furthermore, we constructed the first single-cell atlas of Tibetan sheep ovary tissues and identified a specific mural granulosa cell subtype with PAPPA-specific expression and differential expression of BMPR1B between the two groups. Bulk RNA-seq indicated that BMPR1B and PAPPA expressions were similar between the two groups of sheep. 3D protein structure prediction and coimmunoprecipitation analysis indicated that mutation and mutually exclusive exons of BMPR1B are the main mechanisms for prolific Tibetan sheep. We propose that PAPPA is a key gene for stimulating ovarian follicular growth and development, and steroidogenesis. Our work reveals the genetic variation in reproductive performance in Tibetan sheep, providing insights and valuable genetic resources for the discovery of genes and regulatory mechanisms that improve reproductive success.


Asunto(s)
Estudio de Asociación del Genoma Completo , Multiómica , Humanos , Femenino , Ovinos/genética , Animales , Tibet , Proteómica , Reproducción , Mutación
20.
Mol Biol Evol ; 41(2)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38266195

RESUMEN

The cross-species characterization of evolutionary changes in the functional genome can facilitate the translation of genetic findings across species and the interpretation of the evolutionary basis underlying complex phenotypes. Yet, this has not been fully explored between cattle, sheep, goats, and other mammals. Here, we systematically characterized the evolutionary dynamics of DNA methylation and gene expression in 3 somatic tissues (i.e. brain, liver, and skeletal muscle) and sperm across 7 mammalian species, including 3 ruminant livestock species (cattle, sheep, and goats), humans, pigs, mice, and dogs, by generating and integrating 160 DNA methylation and transcriptomic data sets. We demonstrate dynamic changes of DNA hypomethylated regions and hypermethylated regions in tissue-type manner across cattle, sheep, and goats. Specifically, based on the phylo-epigenetic model of DNA methylome, we identified a total of 25,074 hypomethylated region extension events specific to cattle, which participated in rewiring tissue-specific regulatory network. Furthermore, by integrating genome-wide association studies of 50 cattle traits, we provided novel insights into the genetic and evolutionary basis of complex phenotypes in cattle. Overall, our study provides a valuable resource for exploring the evolutionary dynamics of the functional genome and highlights the importance of cross-species characterization of multiomics data sets for the evolutionary interpretation of complex phenotypes in cattle livestock.


Asunto(s)
Bovinos , Metilación de ADN , Cabras , Ovinos , Animales , Bovinos/genética , Perros , Humanos , Masculino , Ratones , Estudio de Asociación del Genoma Completo , Cabras/genética , Herencia Multifactorial , Ovinos/genética , Porcinos
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