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1.
Immunity ; 45(4): 861-876, 2016 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-27760340

RESUMO

Mycobacterium tuberculosis infection in humans triggers formation of granulomas, which are tightly organized immune cell aggregates that are the central structure of tuberculosis. Infected and uninfected macrophages interdigitate, assuming an altered, flattened appearance. Although pathologists have described these changes for over a century, the molecular and cellular programs underlying this transition are unclear. Here, using the zebrafish-Mycobacterium marinum model, we found that mycobacterial granuloma formation is accompanied by macrophage induction of canonical epithelial molecules and structures. We identified fundamental macrophage reprogramming events that parallel E-cadherin-dependent mesenchymal-epithelial transitions. Macrophage-specific disruption of E-cadherin function resulted in disordered granuloma formation, enhanced immune cell access, decreased bacterial burden, and increased host survival, suggesting that the granuloma can also serve a bacteria-protective role. Granuloma macrophages in humans with tuberculosis were similarly transformed. Thus, during mycobacterial infection, granuloma macrophages are broadly reprogrammed by epithelial modules, and this reprogramming alters the trajectory of infection and the associated immune response.


Assuntos
Epitélio/imunologia , Macrófagos/imunologia , Mycobacterium marinum/imunologia , Animais , Caderinas/imunologia , Epitélio/microbiologia , Granuloma/imunologia , Granuloma/microbiologia , Macrófagos/microbiologia , Mycobacterium tuberculosis/imunologia , Peixe-Zebra
2.
PLoS Genet ; 17(9): e1009474, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34478434

RESUMO

Social interactions have large effects on individual physiology and fitness. In the immediate sense, social stimuli are often highly salient and engaging. Over longer time scales, competitive interactions often lead to distinct social ranks and differences in physiology and behavior. Understanding how initial responses lead to longer-term effects of social interactions requires examining the changes in responses over time. Here we examined the effects of social interactions on transcriptomic signatures at two times, at the end of a 45-minute interaction and 4 hours later, in female Polistes fuscatus paper wasp foundresses. Female P. fuscatus have variable facial patterns that are used for visual individual recognition, so we separately examined the transcriptional dynamics in the optic lobe and the non-visual brain. Results demonstrate much stronger transcriptional responses to social interactions in the non-visual brain compared to the optic lobe. Differentially regulated genes in response to social interactions are enriched for memory-related transcripts. Comparisons between winners and losers of the encounters revealed similar overall transcriptional profiles at the end of an interaction, which significantly diverged over the course of 4 hours, with losers showing changes in expression levels of genes associated with aggression and reproduction in paper wasps. On nests, subordinate foundresses are less aggressive, do more foraging and lay fewer eggs compared to dominant foundresses and we find losers shift expression of many genes in the non-visual brain, including vitellogenin, related to aggression, worker behavior, and reproduction within hours of losing an encounter. These results highlight the early neurogenomic changes that likely contribute to behavioral and physiological effects of social status changes in a social insect.


Assuntos
Comportamento Animal , Genoma de Inseto , Comportamento Social , Vespas/fisiologia , Agressão , Animais , Encéfalo/fisiologia , Feminino , Regulação da Expressão Gênica , Vespas/genética
3.
Mol Ecol ; 32(16): 4546-4556, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37350360

RESUMO

Deleterious variants are selected against but can linger in populations at low frequencies for long periods of time, decreasing fitness and contributing to disease burden in humans and other species. Deleterious variants occur at low frequency but distinguishing deleterious variants from low-frequency neutral variation is challenging based on population genomics data alone. As a result, we have little sense of the number and identity of deleterious variants in wild populations. For haplodiploid species, it has been hypothesised that deleterious alleles will be directly exposed to selection in haploid males, but selection can be masked in diploid females when deleterious variants are recessive, resulting in more efficient purging of deleterious mutations in males. Therefore, comparisons of the differences between haploid and diploid genomes from the same population may be a useful method for inferring rare deleterious variants. This study provides the first formal test of this hypothesis. Using wild populations of Northern paper wasps (Polistes fuscatus), we find that males have fewer missense and nonsense variants per generation than females from the same population. Allele frequency differences are especially pronounced for rare missense and nonsense variants and these differences lead to a lower mutational load in males than females. Based on these data we infer that many highly deleterious mutations are segregating in the paper wasp population. Stronger selection against deleterious alleles in haploid males may have implications for adaptation in other haplodiploid insects and provides evidence that wild populations harbour abundant deleterious variants.


Assuntos
Caracteres Sexuais , Vespas , Animais , Humanos , Feminino , Masculino , Frequência do Gene/genética , Diploide , Haploidia , Vespas/genética , Seleção Genética
4.
Proc Natl Acad Sci U S A ; 117(6): 3045-3052, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-31980529

RESUMO

Cognitive abilities can vary dramatically among species. The relative importance of social and ecological challenges in shaping cognitive evolution has been the subject of a long-running and recently renewed debate, but little work has sought to understand the selective dynamics underlying the evolution of cognitive abilities. Here, we investigate recent selection related to cognition in the paper wasp Polistes fuscatus-a wasp that has uniquely evolved visual individual recognition abilities. We generate high quality de novo genome assemblies and population genomic resources for multiple species of paper wasps and use a population genomic framework to interrogate the probable mode and tempo of cognitive evolution. Recent, strong, hard selective sweeps in P. fuscatus contain loci annotated with functions in long-term memory formation, mushroom body development, and visual processing, traits which have recently evolved in association with individual recognition. The homologous pathways are not under selection in closely related wasps that lack individual recognition. Indeed, the prevalence of candidate cognition loci within the strongest selective sweeps suggests that the evolution of cognitive abilities has been among the strongest selection pressures in P. fuscatus' recent evolutionary history. Detailed analyses of selective sweeps containing candidate cognition loci reveal multiple cases of hard selective sweeps within the last few thousand years on de novo mutations, mainly in noncoding regions. These data provide unprecedented insight into some of the processes by which cognition evolves.


Assuntos
Evolução Biológica , Cognição/fisiologia , Seleção Genética/genética , Vespas/genética , Vespas/fisiologia , Animais , Genoma de Inseto/genética , Reconhecimento Psicológico/fisiologia
5.
Aging Ment Health ; 27(10): 2070-2077, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36636788

RESUMO

Objectives: Sense of control (i.e. one's beliefs about their ability to influence life circumstances) has been linked to various psychological outcomes. However, it is unknown if sense of control is protective against prescription drug misuse (PDM). The present study sought to evaluate if sense of control is associated with reduced odds of PDM 9 to 10 years later among a sample of middle-aged and older adults.Methods: Data were evaluated from participants (M = 54 years, SD = 10.86; N = 2,108) of the second and third waves of the Midlife in the United States study. Logistic regression models were used to assess whether baseline sense of control (Wave 2) predicted odds of PDM 9 to 10 years later (Wave 3).Results: Findings revealed that greater sense of control at baseline was related to reduced odds of subsequent PDM (OR = 0.78; 95% CI: 0.64, 0.95), adjusting for baseline PDM, sociodemographic characteristics, health behaviors, psychological factors, number of prescription medications, and health. When assessing the subscales of sense of control separately, constraints (OR = 1.19; 95% CI: 1.00, 1.42), but not mastery (OR = 0.96; 95% CI: 0.80, 1.12), was predictive of odds of subsequent PDM. Further, being female was associated with greater odds of PDM (OR = 1.46; 95% CI: 1.02, 2.09), but did not moderate the association between sense of control and PDM.Conclusions: Sense of control may be a novel and viable target for interventions (e.g. using mobile phone apps) aimed at mitigating prescription drug misuse.


Assuntos
Uso Indevido de Medicamentos sob Prescrição , Transtornos Relacionados ao Uso de Substâncias , Humanos , Feminino , Estados Unidos/epidemiologia , Pessoa de Meia-Idade , Idoso , Masculino , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/prevenção & controle , Transtornos Relacionados ao Uso de Substâncias/psicologia , Controle Interno-Externo , Uso Indevido de Medicamentos sob Prescrição/prevenção & controle , Uso Indevido de Medicamentos sob Prescrição/psicologia , Comportamentos Relacionados com a Saúde
6.
J Fam Issues ; 44(7): 1838-1858, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37483651

RESUMO

This study evaluated whether recent family member alcohol and substance use problems (ASP) and density of family ASP (i.e., number of members with ASP) predict alcohol-related problems and drug use-related problems among middle-aged and older adults. Data were drawn from participants (age 42-93 years, n=2,168) in the longitudinal Midlife in the United States Study (MIDUS). Poisson regression models revealed that adults' alcohol- and drug use-related problems were predicted by similar problems among family members. In particular, parent and partner ASP, but not child ASP, predicted alcohol-related problems in the middle-aged and combined samples, while only partner ASP predicted participants' drug use-related problems. In addition, density of family ASP predicted alcohol-related problems, but not drug use-related problems. There were no gender interactions. Study findings highlight that understanding how adult children, spouses, and aging parents impact each other's substance use should be a priority of future aging and family research.

7.
Mol Biol Evol ; 38(9): 3832-3846, 2021 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-34151983

RESUMO

Independent origins of sociality in bees and ants are associated with independent expansions of particular odorant receptor (OR) gene subfamilies. In ants, one clade within the OR gene family, the 9-exon subfamily, has dramatically expanded. These receptors detect cuticular hydrocarbons (CHCs), key social signaling molecules in insects. It is unclear to what extent 9-exon OR subfamily expansion is associated with the independent evolution of sociality across Hymenoptera, warranting studies of taxa with independently derived social behavior. Here, we describe OR gene family evolution in the northern paper wasp, Polistes fuscatus, and compare it to four additional paper wasp species spanning ∼40 million years of evolutionary divergence. We find 200 putatively functional OR genes in P. fuscatus, matching predictions from neuroanatomy, and more than half of these are in the 9-exon subfamily. Most OR gene expansions are tandemly arrayed at orthologous loci in Polistes genomes, and microsynteny analysis shows species-specific gain and loss of 9-exon ORs within tandem arrays. There is evidence of episodic positive diversifying selection shaping ORs in expanded subfamilies. Values of omega (dN/dS) are higher among 9-exon ORs compared to other OR subfamilies. Within the Polistes OR gene tree, branches in the 9-exon OR clade experience relaxed negative (relaxed purifying) selection relative to other branches in the tree. Patterns of OR evolution within Polistes are consistent with 9-exon OR function in CHC perception by combinatorial coding, with both natural selection and neutral drift contributing to interspecies differences in gene copy number and sequence.


Assuntos
Receptores Odorantes , Vespas , Animais , Éxons , Receptores Odorantes/genética , Vespas/genética
8.
Emerg Infect Dis ; 27(4): 1023-1031, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33600302

RESUMO

Efforts to combat the coronavirus disease (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have placed a renewed focus on the use of transmission electron microscopy for identifying coronavirus in tissues. In attempts to attribute pathology of COVID-19 patients directly to tissue damage caused by SARS-CoV-2, investigators have inaccurately reported subcellular structures, including coated vesicles, multivesicular bodies, and vesiculating rough endoplasmic reticulum, as coronavirus particles. We describe morphologic features of coronavirus that distinguish it from subcellular structures, including particle size range (60-140 nm), intracellular particle location within membrane-bound vacuoles, and a nucleocapsid appearing in cross section as dense dots (6-12 nm) within the particles. In addition, although the characteristic spikes of coronaviruses may be visible on the virus surface, especially on extracellular particles, they are less evident in thin sections than in negative stain preparations.


Assuntos
COVID-19 , Estruturas Celulares , SARS-CoV-2 , Biópsia/métodos , COVID-19/patologia , COVID-19/virologia , Estruturas Celulares/classificação , Estruturas Celulares/ultraestrutura , Humanos , Microscopia Eletrônica/métodos , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/ultraestrutura
9.
Kidney Int ; 99(4): 824-827, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33493525

RESUMO

This guidance provides clear, concise strategies for identifying coronaviruses by transmission electron microscopy of ultrathin sections of tissues or infected tissue cultures. These include a description of virus morphology as well as cell organelles that can resemble viruses. Biochemical testing and caveats are discussed. Numerous references provide information for documentation and further study.


Assuntos
Teste para COVID-19 , COVID-19/diagnóstico , Microscopia Eletrônica de Transmissão , SARS-CoV-2/ultraestrutura , Benchmarking , COVID-19/virologia , Humanos , Valor Preditivo dos Testes , Reprodutibilidade dos Testes
10.
Mod Pathol ; 34(9): 1614-1633, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34031537

RESUMO

The severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) pandemic has had devastating effects on global health and worldwide economy. Despite an initial reluctance to perform autopsies due to concerns for aerosolization of viral particles, a large number of autopsy studies published since May 2020 have shed light on the pathophysiology of Coronavirus disease 2019 (COVID-19). This review summarizes the histopathologic findings and clinicopathologic correlations from autopsies and biopsies performed in patients with COVID-19. PubMed and Medline (EBSCO and Ovid) were queried from June 4, 2020 to September 30, 2020 and histopathologic data from autopsy and biopsy studies were collected based on 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 58 studies reporting 662 patients were included. Demographic data, comorbidities at presentation, histopathologic findings, and virus detection strategies by organ system were collected. Diffuse alveolar damage, thromboembolism, and nonspecific shock injury in multiple organs were the main findings in this review. The pathologic findings emerging from autopsy and biopsy studies reviewed herein suggest that in addition to a direct viral effect in some organs, a unifying pathogenic mechanism for COVID-19 is ARDS with its known and characteristic inflammatory response, cytokine release, fever, inflammation, and generalized endothelial disturbance. This study supports the notion that autopsy studies are of utmost importance to our understanding of disease features and treatment effect to increase our knowledge of COVID-19 pathophysiology and contribute to more effective treatment strategies.


Assuntos
COVID-19/patologia , Síndrome do Desconforto Respiratório/patologia , Síndrome do Desconforto Respiratório/virologia , Humanos , SARS-CoV-2
11.
Histopathology ; 78(3): 358-370, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32981112

RESUMO

Transmission electron microscopy has become a valuable tool to investigate tissues of COVID-19 patients because it allows visualisation of SARS-CoV-2, but the 'virus-like particles' described in several organs have been highly contested. Because most electron microscopists in pathology are not accustomed to analysing viral particles and subcellular structures, our review aims to discuss the ultrastructural changes associated with SARS-CoV-2 infection and COVID-19 with respect to pathology, virology and electron microscopy. Using micrographs from infected cell cultures and autopsy tissues, we show how coronavirus replication affects ultrastructure and put the morphological findings in the context of viral replication, which induces extensive remodelling of the intracellular membrane systems. Virions assemble by budding into the endoplasmic reticulum-Golgi intermediate complex and are characterised by electron-dense dots of cross-sections of the nucleocapsid inside the viral particles. Physiological mimickers such as multivesicular bodies or coated vesicles serve as perfect decoys. Compared to other in-situ techniques, transmission electron microscopy is the only method to visualise assembled virions in tissues, and will be required to prove SARS-CoV-2 replication outside the respiratory tract. In practice, documenting in tissues the characteristic features seen in infected cell cultures seems to be much more difficult than anticipated. In our view, the hunt for coronavirus by transmission electron microscopy is still on.


Assuntos
COVID-19/patologia , SARS-CoV-2/ultraestrutura , COVID-19/virologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Humanos , Microscopia Eletrônica de Transmissão , RNA Viral , SARS-CoV-2/fisiologia , Vírion/ultraestrutura , Montagem de Vírus , Replicação Viral
12.
Kidney Int ; 98(5): 1296-1307, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32791255

RESUMO

Coronavirus disease 2019 (COVID-19) is commonly associated with kidney damage, and the angiotensin converting enzyme 2 (ACE2) receptor for SARS-CoV-2 is highly expressed in the proximal tubule cells. Whether patients with COVID-19 present specific manifestations of proximal tubule dysfunction remains unknown. To test this, we examined a cohort of 49 patients requiring hospitalization in a large academic hospital in Brussels, Belgium. There was evidence of proximal tubule dysfunction in a subset of patients with COVID-19, as attested by low-molecular-weight proteinuria (70-80%), neutral aminoaciduria (46%), and defective handling of uric acid (46%) or phosphate (19%). None of the patients had normoglycemic glucosuria. Proximal tubule dysfunction was independent of pre-existing comorbidities, glomerular proteinuria, nephrotoxic medications or viral load. At the structural level, kidneys from patients with COVID-19 showed prominent tubular injury, including in the initial part of the proximal tubule, with brush border loss, acute tubular necrosis, intraluminal debris, and a marked decrease in the expression of megalin in the brush border. Transmission electron microscopy identified particles resembling coronaviruses in vacuoles or cisternae of the endoplasmic reticulum in proximal tubule cells. Among features of proximal tubule dysfunction, hypouricemia with inappropriate uricosuria was independently associated with disease severity and with a significant increase in the risk of respiratory failure requiring invasive mechanical ventilation using Cox (adjusted hazard ratio 6.2, 95% CI 1.9-20.1) or competing risks (adjusted sub-distribution hazard ratio 12.1, 95% CI 2.7-55.4) survival models. Thus, our data establish that SARS-CoV-2 causes specific manifestations of proximal tubule dysfunction and provide novel insights into COVID-19 severity and outcome.


Assuntos
Infecções por Coronavirus/fisiopatologia , Túbulos Renais Proximais/fisiopatologia , Pneumonia Viral/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Bélgica/epidemiologia , Betacoronavirus , COVID-19 , Estudos de Casos e Controles , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/patologia , Infecções por Coronavirus/terapia , Humanos , Túbulos Renais Proximais/ultraestrutura , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/mortalidade , Pneumonia Viral/patologia , Pneumonia Viral/terapia , SARS-CoV-2
13.
Am Nat ; 195(2): 192-200, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32017617

RESUMO

Closely related populations often display similar patterns of genomic differentiation, yet it remains an open question which ecological and evolutionary forces generate these patterns. The leading hypothesis is that this similarity in divergence is driven by parallel natural selection. However, several recent studies have suggested that these patterns may instead be a product of the depletion of genetic variation that occurs as result of background selection (i.e., linked negative selection). To date, there have been few direct tests of these competing hypotheses. To determine the relative contributions of background selection and parallel selection to patterns of repeated differentiation, we examined 24 independently derived populations of freshwater stickleback occupying a variety of niches and estimated genomic patterns of differentiation in each relative to their common marine ancestor. Patterns of genetic differentiation were strongly correlated across pairs of freshwater populations adapting to the same ecological niche, supporting a role for parallel natural selection. In contrast to other recent work, our study comparing populations adapting to the same niche produced no evidence signifying that similar patterns of genomic differentiation are generated by background selection. We also found that overall patterns of genetic differentiation were considerably more similar for populations found in closer geographic proximity. In fact, the effect of geography on the repeatability of differentiation was greater than that of parallel selection. Our results suggest that shared selective landscapes and ancestral variation are the key drivers of repeated patterns of differentiation in systems that have recently colonized novel environments.


Assuntos
Ecossistema , Seleção Genética , Smegmamorpha/genética , Adaptação Fisiológica/genética , Animais , Evolução Biológica , Água Doce , Variação Genética , Genética Populacional , Geografia , Polimorfismo de Nucleotídeo Único , Água do Mar
14.
Appetite ; 135: 100-107, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30634008

RESUMO

OBJECTIVE: The present study examined whether different sleep health parameters (duration, timing, and quality) are associated with obesity-related eating behaviors including emotional overeating, food responsiveness, enjoyment of food, satiety responsiveness, and eating in the absence of hunger (EAH), during toddlerhood. DESIGN: Among 134 low-income 33-month-old children, parents reported on child sleep parameters, including sleep quality (Children's Sleep Wake Scale; CSWS) and usual bedtimes and wake times on weekdays and weekends (weeknight sleep duration, weekday-to-weekend bedtime delay). Child eating behaviors were assessed using both observed and parent-report measures. Child Emotional Overeating, Food Responsiveness, Enjoyment of Food, and Satiety Responsiveness were measured by parent report using the Child Eating Behavior Questionnaire-Toddler. Observed child EAH was evaluated by measuring kilocalories of palatable foods consumed following a meal. Multivariable linear regression was used to examine the associations between sleep parameters and eating behaviors. RESULTS: Poorer child sleep quality was associated with greater Emotional Overeating (standardized ß = -0.20 (SE 0.09), p < .05) and greater Food Responsiveness (ß = -0.18 (SE 0.09), p < .05). Shorter child nighttime sleep duration was associated with greater EAH kcal consumed (standardized ß = -0.22 (SE 0.09), p < .05). Child bedtime delay was not associated with any of the eating behaviors, and no child sleep variables were associated with either Enjoyment of Food or Satiety Responsiveness. CONCLUSIONS: Shorter nocturnal sleep duration and poorer sleep quality during toddlerhood were associated with some, but not all, of the obesity-related eating behaviors. Poor sleep health may promote childhood obesity risk through different eating behavior pathways. As children growing up in poverty may experience greater sleep decrements, sleep duration and sleep quality may be important targets for intervention among low-income families with young children.


Assuntos
Comportamento Infantil , Comportamento Alimentar , Hiperfagia/etiologia , Obesidade Infantil/etiologia , Pobreza , Resposta de Saciedade , Sono , Desenvolvimento Infantil , Pré-Escolar , Ingestão de Alimentos , Emoções , Ingestão de Energia , Feminino , Humanos , Fome , Hiperfagia/psicologia , Masculino , Obesidade Infantil/psicologia , Inquéritos e Questionários
16.
Ecology ; 99(10): 2405, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29999519

RESUMO

Cooperative breeding decreases the direct reproductive output of subordinate individuals, but cooperation can be evolutionarily favored when there are challenges or constraints to breeding independently. Environmental factors, including temperature, precipitation, latitude, high seasonality, and environmental harshness have been hypothesized to correlate with the presence of cooperative breeding. However, to test the relationship between cooperation and ecological constraints requires comparative data on the frequency and variation of cooperative breeding across differing environments, ideally replicated across multiple species. Paper wasps are primitively social species, forming colonies composed of reproductively active dominants and foraging subordinates. Adult female wasps, referred to as foundresses, initiate new colonies. Nests can be formed by a single solitary foundress (noncooperative) or by multiple foundress associations (cooperative). Cooperative behavior varies within and among species, making paper wasps species well suited to disentangling ecological correlates of variation in cooperative behavior. This data set reports the frequency and extent of cooperative nest founding for 87 paper wasp species. Data were assembled from more than 170 published sources, previously unpublished field observations, and photographs contributed by citizen scientists to online natural history repositories. The data set includes 25,872 nest observations and reports the cooperative behavioral decisions for 45,297 foundresses. Species names were updated to reflect modern taxonomic revisions. The type of substrate on which the nest was built is also included, when available. A smaller population-level version of this data set found that the presence or absence of cooperative nesting in paper wasps was correlated with temperature stability and environmental harshness, but these variables did not predict the extent of cooperation within species. This expanded data set contains details about individual nests and further increases the power to address the relationship between the environment and the presence and extent of cooperative breeding. Beyond the ecological drivers of cooperation, these high-resolution data will be useful for future studies examining the evolutionary consequences of variation in social behavior. This data set may be used for research or educational purposes provided that this data paper is cited.

17.
Microsc Microanal ; 24(5): 553-563, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30334512

RESUMO

Emerging evidence from various studies indicates that plasmid DNA (pDNA) is internalized by cells through an endocytosis-like process when it is used for electrotransfection. To provide morphological evidence of the process, we investigated ultrastructures in cells that were associated with the electrotransfected pDNA, using immunoelectron microscopy. The results demonstrate that four endocytic pathways are involved in the uptake of the pDNA, including caveolae- and clathrin-mediated endocytosis, macropinocytosis, and the clathrin-independent carrier/glycosylphosphatidylinositol-anchored protein-enriched early endosomal compartment (CLIC/GEEC) pathway. Among them, macropinocytosis is the most common pathway utilized by cells having various pDNA uptake capacities, and the CLIC/GEEC pathway is observed primarily in human umbilical vein endothelial cells. Quantitatively, the endocytic pathways are more active in easy-to-transfect cells than in hard-to-transfect ones. Taken together, our data provide ultrastructural evidence showing that endocytosis plays an important role in cellular uptake and intracellular transport of electrotransfected pDNA.


Assuntos
Endocitose/fisiologia , Transfecção/métodos , Vesículas Transportadoras/genética , Vesículas Transportadoras/ultraestrutura , Transporte Biológico/genética , Transporte Biológico/fisiologia , Proteínas de Ciclo Celular , Linhagem Celular , Clatrina , DNA/metabolismo , Digoxina , Eletricidade , Células Endoteliais , Proteínas Ligadas por GPI , Técnicas de Transferência de Genes , Humanos , Microscopia Imunoeletrônica/métodos , Pinocitose , Plasmídeos/genética , Plasmídeos/metabolismo , Inclusão do Tecido , Vesículas Transportadoras/fisiologia , Veias
18.
Mol Ecol ; 26(17): 4378-4390, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28667780

RESUMO

Adaptation to new environments often occurs in the face of gene flow. Under these conditions, gene flow and recombination can impede adaptation by breaking down linkage disequilibrium between locally adapted alleles. Theory predicts that this decay can be halted or slowed if adaptive alleles are tightly linked in regions of low recombination, potentially favouring divergence and adaptive evolution in these regions over others. Here, we compiled a global genomic data set of over 1,300 individual threespine stickleback from 52 populations and compared the tendency for adaptive alleles to occur in regions of low recombination between populations that diverged with or without gene flow. In support of theory, we found that putatively adaptive alleles (FST and dXY outliers) tend to occur more often in regions of low recombination in populations where divergent selection and gene flow have jointly occurred. This result remained significant when we employed different genomic window sizes, controlled for the effects of mutation rate and gene density, controlled for overall genetic differentiation, varied the genetic map used to estimate recombination and used a continuous (rather than discrete) measure of geographic distance as proxy for gene flow/shared ancestry. We argue that our study provides the first statistical evidence that the interaction of gene flow and selection biases divergence toward regions of low recombination.


Assuntos
Fluxo Gênico , Genética Populacional , Seleção Genética , Smegmamorpha/genética , Alelos , Animais , Recombinação Genética
19.
Mol Biol Evol ; 32(2): 481-94, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25398629

RESUMO

Changes in exon-intron structures and splicing patterns represent an important mechanism for the evolution of gene functions and species-specific regulatory networks. Although exon creation is widespread during primate and human evolution and has been studied extensively, much less is known about the scope and potential impact of human-specific exon loss events. Historically, transcriptome data and exon annotations are significantly biased toward humans over nonhuman primates. This ascertainment bias makes it challenging to discover human-specific exon loss events. We carried out a transcriptome-wide search of human-specific exon loss events, by taking advantage of RNA sequencing (RNA-seq) as a powerful and unbiased tool for exon discovery and annotation. Using RNA-seq data of humans, chimpanzees, and other primates, we reconstructed and compared transcript structures across the primate phylogeny. We discovered 33 candidate human-specific exon loss events, among which six exons passed stringent experimental filters for the complete loss of splicing activities in diverse human tissues. These events may result from human-specific deletion of genomic DNA, or small-scale sequence changes that inactivated splicing signals. The impact of human-specific exon loss events is predominantly regulatory. Three of the six events occurred in the 5' untranslated region (5'-UTR) and affected cis-regulatory elements of mRNA translation. In SLC7A6, a gene encoding an amino acid transporter, luciferase reporter assays suggested that both a human-specific exon loss event and an independent human-specific single nucleotide substitution in the 5'-UTR increased mRNA translational efficiency. Our study provides novel insights into the molecular mechanisms and evolutionary consequences of exon loss during human evolution.


Assuntos
Éxons/genética , Transcriptoma/genética , Sistemas de Transporte de Aminoácidos Básicos/genética , Animais , Evolução Molecular , Humanos , Primatas/genética
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