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BACKGROUND: Substantial discoveries during the past century have revealed that transposable elements (TEs) can play a crucial role in genome evolution by affecting gene expression and inducing genetic rearrangements, among other molecular and structural effects. Yet, our knowledge on the role of TEs in adaptation to extreme climates is still at its infancy. The availability of long-read sequencing has opened up the possibility to identify and study potential functional effects of TEs with higher precision. In this work, we used Drosophila montana as a model for cold-adapted organisms to study the association between TEs and adaptation to harsh climates. RESULTS: Using the PacBio long-read sequencing technique, we de novo identified and manually curated TE sequences in five Drosophila montana genomes from eco-geographically distinct populations. We identified 489 new TE consensus sequences which represented 92% of the total TE consensus in D. montana. Overall, 11-13% of the D. montana genome is occupied by TEs, which as expected are non-randomly distributed across the genome. We identified five potentially active TE families, most of them from the retrotransposon class of TEs. Additionally, we found TEs present in the five analyzed genomes that were located nearby previously identified cold tolerant genes. Some of these TEs contain promoter elements and transcription binding sites. Finally, we detected TEs nearby fixed and polymorphic inversion breakpoints. CONCLUSIONS: Our research revealed a significant number of newly identified TE consensus sequences in the genome of D. montana, suggesting that non-model species should be studied to get a comprehensive view of the TE repertoire in Drosophila species and beyond. Genome annotations with the new D. montana library allowed us to identify TEs located nearby cold tolerant genes, and present at high population frequencies, that contain regulatory regions and are thus good candidates to play a role in D. montana cold stress response. Finally, our annotations also allow us to identify for the first time TEs present in the breakpoints of three D. montana inversions.
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[This corrects the article DOI: 10.3389/fmed.2023.1156557.].
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The epigenome is the suite of interacting chemical marks and molecules that helps to shape patterns of development, phenotypic plasticity and gene regulation, in part due to its responsiveness to environmental stimuli. There is increasing interest in understanding the functional and evolutionary importance of this sensitivity under ecologically realistic conditions. Observations that epigenetic variation abounds in natural populations have prompted speculation that it may facilitate evolutionary responses to rapid environmental perturbations, such as those occurring under climate change. A frequent point of contention is whether epigenetic variants reflect genetic variation or are independent of it. The genome and epigenome often appear tightly linked and interdependent. While many epigenetic changes are genetically determined, the converse is also true, with DNA sequence changes influenced by the presence of epigenetic marks. Understanding how the epigenome, genome and environment interact with one another is therefore an essential step in explaining the broader evolutionary consequences of epigenomic variation. Drawing on results from experimental and comparative studies carried out in diverse plant and animal species, we synthesize our current understanding of how these factors interact to shape phenotypic variation in natural populations, with a focus on identifying similarities and differences between taxonomic groups. We describe the main components of the epigenome and how they vary within and between taxa. We review how variation in the epigenome interacts with genetic features and environmental determinants, with a focus on the role of transposable elements (TEs) in integrating the epigenome, genome and environment. And we look at recent studies investigating the functional and evolutionary consequences of these interactions. Although epigenetic differentiation in nature is likely often a result of drift or selection on stochastic epimutations, there is growing evidence that a significant fraction of it can be stably inherited and could therefore contribute to evolution independently of genetic change.
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RNA sequencing (RNAseq) methodology has experienced a burst of technological developments in the last decade, which has opened up opportunities for studying the mechanisms of adaptation to environmental factors at both the organismal and cellular level. Selecting the most suitable experimental approach for specific research questions and model systems can, however, be a challenge and researchers in ecology and evolution are commonly faced with the choice of whether to study gene expression variation in whole bodies, specific tissues, and/or single cells. A wide range of sometimes polarised opinions exists over which approach is best. Here, we highlight the advantages and disadvantages of each of these approaches to provide a guide to help researchers make informed decisions and maximise the power of their study. Using illustrative examples of various ecological and evolutionary research questions, we guide the readers through the different RNAseq approaches and help them identify the most suitable design for their own projects.
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This study examined the association of clinical factors, independent of sex and high psychosocial adversity (HPAd), with the presence of ADHD or other mental disorders, specifically within a middle-income country with a non-Caucasian population. A multi-centric cross-sectional study was conducted in three sites in Colombia. Our study recruited trios of an ADHD proband, one sibling, and one parent. We used valid instruments for assessing parents and siblings. The sample included 223 siblings, an average age of 12.3 (SD 3.9), and 51.1% Females. The ADHD recurrence risk ratio (λ) was 12. The clinical factors mainly associated with the presence of ADHD, independent of sex and HPAd, were 1) Pregnancy and childbirth complications, 2) Delayed psychomotor development, 3) Temperament, and 4) Sleep disturbances. Our research showed that, independently of HPAd and the male sex, there were other clinical factors associated with ADHD and other psychiatric disorders in this population. These findings need to be replicated in similar populations globally.
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Trastorno por Déficit de Atención con Hiperactividad , Trastornos Mentales , Hermanos , Humanos , Femenino , Masculino , Colombia , Hermanos/psicología , Estudios Transversales , Niño , Adolescente , Trastornos Mentales/epidemiología , Factores Sexuales , Experiencias Adversas de la Infancia/estadística & datos numéricos , Factores de RiesgoRESUMEN
Introduction: Psoriatic arthritis (PsA) is a complex and heterogeneous inflammatory disease. Secukinumab, a biologic disease-modifying antirheumatic drug (bDMARD), has extensive clinical evidence of efficacy and safety in the treatment of PsA but data in clinical practice are still limited. This study aims to provide real-world evidence on secukinumab use, effectiveness, and persistence in PsA. Methods: A retrospective, multicenter study was conducted on patients diagnosed with PsA and treated with secukinumab up to June 2021 at 12 centers in the Valencian Community (Spain). Data on DAS28-CRP, DAPSA, Tender and Swollen Joint Counts (TJC, SJC), enthesitis, dactylitis, skin and nail involvement, pain, patient and physician global assessment (ptGA, phGA) using 100-mm visual analog scale (VAS), and persistence for up to 24 months were collected. Results: A total of 178 patients were included (49% men; mean [standard deviation, SD] age: 51.4 [10.5] years; 39% obese). Secukinumab was used as a first-, second-, or ≥ third-line bDMARD in 37, 21, and 42% of patients, respectively. The percentage of patients achieving at least low disease activity (DAS28-CRP ≤ 3.2) increased from 25% at baseline to 66% at month 6 (M6) and was maintained (75%) up to M24. Mean (SD) DAS28-CRP baseline values (3.9 [1.2]) decreased to 2.9 (1.1) (p < 0.001) at M6 and remained low through M24 (2.6 [1.1]) (p < 0.001). Secukinumab also improved peripheral arthritis increasing the percentage of patients with TJC = 0 (20% baseline; 57% M24) and SJC = 0 (37% baseline; 80% M24). Treatment reduced the percentage of patients with enthesitis (25% baseline; 6% M24), dactylitis (20% baseline; 4% M24), and skin (70% baseline; 17% M24), and nail (32% baseline; 2% M24) involvement. Additionally, we observed improvements in the mean pain VAS (-26.4 mm M24), ptGA (-26.2 mm M24), and phGA (-24.8 mm M24). Secukinumab showed an overall 24-month persistence rate of 67% (95% confidence interval [CI]: 60-74%). Patients receiving first-line secukinumab showed the highest 24-month persistence rate (83, 95% CI: 73-92; p = 0.024). Conclusion: Secukinumab showed long-term effectiveness across the six key PsA domains thus reducing disease activity and pain, which are major treatment goals. This was accompanied by high persistence rates, especially in bDMARD naive patients.
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OBJECTIVE: We aim to determine the prevalence of mental disorders in siblings of children with attention deficit hyperactivity disorder (ADHD), and to determine how psychosocial adversity factors relate to this psychopathology, in a low-middle income country (Colombia). METHODS: We evaluated subjects with ADHD diagnosed according to the DSM-5 criteria, one of their parents and one of their siblings (ages 8-19). We used the ADHD rating scale and a set of instruments to assess the presence of mental disorders as well as psychosocial adversity. RESULTS: We evaluated 74 trios formed by the index case with ADHD, one sibling and one of the parents. We found that 24.3% of the participating siblings also met the criteria for ADHD and another 24.3% for other psychiatric disorders. The risk of these siblings having ADHD increased further when one of the parents reported a history of ADHD. We also found that 28.3% of the families faced high levels of psychosocial adversity as per their scores in the Rutter Adversity Index. CONCLUSIONS: Siblings of subjects with ADHD showed a significant risk for ADHD and other mental disorders. That risk increased if a parent reported a history of ADHD and also when two or more psychosocial adversity factors were present. This study supports the importance of early detection in efforts to decrease the risk for other siblings.
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Trastorno por Déficit de Atención con Hiperactividad , Niño , Humanos , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Hermanos , Estudios Transversales , Colombia/epidemiologíaRESUMEN
INTRODUCTION: Stroke, the second leading cause of death worldwide, is a complex disease influenced by many risk factors among which we can find reactive oxygen species (ROS). Since mitochondria are the main producers of cellular ROS, nowadays studies are trying to elucidate the role of these organelles and its DNA (mtDNA) variation in stroke risk. The aim of the present study was to perform a comprehensive evaluation of the association between mtDNA mutations and mtDNA content and stroke risk. MATERIAL AND METHODS: Homoplasmic and heteroplasmic mutations of the mtDNA were analysed in a case-controls study using 110 S cases and their corresponding control individuals. Mitochondrial DNA copy number (mtDNA-CN) was analysed in 73 of those case-control pairs. RESULTS: Our results suggest that haplogroup V, specifically variants m.72C > T, m.4580G > A, m.15904C > T and m.16298 T > C have a protective role in relation to stroke risk. On the contrary, variants m.73A > G, m.11719G > A and m.14766C > T appear to be genetic risk factors for stroke. In this study, we found no statistically significant association between stroke risk and mitochondrial DNA copy number. CONCLUSIONS: These results demonstrate the possible role of mtDNA genetics on the pathogenesis of stroke, probably through alterations in mitochondrial ROS production.
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ADN Mitocondrial , Accidente Cerebrovascular , Humanos , ADN Mitocondrial/genética , Especies Reactivas de Oxígeno , Estudios de Casos y Controles , Predisposición Genética a la Enfermedad , Haplotipos , Mitocondrias/genética , Accidente Cerebrovascular/genéticaRESUMEN
Transcriptomes are dynamic, with cells, tissues, and body parts expressing particular sets of transcripts. Transposable elements (TEs) are a known source of transcriptome diversity; however, studies often focus on a particular type of chimeric transcript, analyze single body parts or cell types, or are based on incomplete TE annotations from a single reference genome. In this work, we have implemented a method based on de novo transcriptome assembly that minimizes the potential sources of errors while identifying a comprehensive set of gene-TE chimeras. We applied this method to the head, gut, and ovary dissected from five Drosophila melanogaster natural strains, with individual reference genomes available. We found that â¼19% of body part-specific transcripts are gene-TE chimeras. Overall, chimeric transcripts contribute a mean of 43% to the total gene expression, and they provide protein domains for DNA binding, catalytic activity, and DNA polymerase activity. Our comprehensive data set is a rich resource for follow-up analysis. Moreover, because TEs are present in virtually all species sequenced to date, their role in spatially restricted transcript expression is likely not exclusive to the species analyzed in this work.
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Drosophila melanogaster , Drosophila , Animales , Femenino , Drosophila/genética , Drosophila melanogaster/genética , Transcriptoma , Ovario , Elementos Transponibles de ADN/genéticaRESUMEN
Objective: We aim to determine the prevalence of mental disorders in siblings of children with attention deficit hyperactivity disorder (ADHD), and to determine how psychosocial adversity factors relate to this psychopathology, in a low-middle income country (Colombia). Methods: We evaluated subjects with ADHD diagnosed according to the DSM-5 criteria, one of their parents and one of their siblings (ages 8-19). We used the ADHD rating scale and a set of instruments to assess the presence of mental disorders as well as psychosocial adversity. Results: We evaluated 74 trios formed by the index case with ADHD, one sibling and one of the parents. We found that 24.3% of the participating siblings also met the criteria for ADHD and another 24.3% for other psychiatric disorders. The risk of these siblings having ADHD increased further when one of the parents reported a history of ADHD. We also found that 28.3% of the families faced high levels of psychosocial adversity as per their scores in the Rutter Adversity Index. Conclusions: Siblings of subjects with ADHD showed a significant risk for ADHD and other mental disorders. That risk increased if a parent reported a history of ADHD and also when two or more psychosocial adversity factors were present. This study supports the importance of early detection in efforts to decrease the risk for other siblings.
Objetivo: Nuestro objetivo es determinar la prevalencia de trastornos mentales en hermanos de casos con TDAH y cómo los factores de adversidad psicosocial se relacionan con esta psicopatología en un país de ingresos bajos-medios (Colombia). Métodos: Se evaluó a sujetos con TDAH diagnosticado según los criterios del DSM-5, uno de sus padres y uno de sus hermanos (edades, 8-19 anos). Mediante la escala de calificación del TDAH y un conjunto de otros instrumentos se evaluó la presencia de trastornos mentales y adversidad psicosocial. Resultados: Se evaluó a 74 tríos formados por el caso índice con TDAH, un hermano y uno de los padres. Se halló que un 24,3% de los hermanos participantes también cumplían los criterios de TDAH y otro 24,3%, otros trastornos psiquiátricos. El riesgo de que estos hermanos tuvieran TDAH aumentó aún más cuando uno de los padres informó antecedentes de TDAH. También, que el 28,3% de las familias se enfrentaron a altos niveles de adversidad psicosocial según sus puntuaciones en el Índice de Adversidad de Rutter. Conclusiones: Los hermanos de sujetos con TDAH mostraron un significativo riesgo de TDAH y otros trastornos mentales. Ese riesgo aumenta si uno de los padres reporta antecedentes de TDAH y también cuando se presentan 2 o más factores de adversidad psicosocial. Este estudio respalda la importancia de la detección temprana con el fin de disminuir el riesgo para otros hermanos.
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Background: Secukinumab is a biologic disease-modifying antirheumatic drug (bDMARD) that has demonstrated efficacy in the treatment of axial spondyloarthritis (axSpA, i.e., ankylosing spondylitis and non-radiographic axSpA) across various clinical trials. However, data of secukinumab in clinical practice is still limited. Here, we aimed to provide real-world data on secukinumab use, effectiveness, and persistence in axSpA. Patients and methods: Retrospective, multicenter study of patients with a diagnosis of axSpA treated with secukinumab at 12 centers up to June 2021 in the Valencian Community (Spain). Information was gathered on BASDAI measurement, pain, patient and physician global assessment (ptGA, phGA) using a 100-mm visual analog scale (VAS), persistence and other secondary variables by treatment line (first, second, and ≥ third) for up to 24 months. Results: 221 patients were included (69% men; mean age [standard deviation, SD]: 46.7 [12.1] years old). Secukinumab was used as a first-line bDMARD in 38% of patients, as a second-line in 34% and as a ≥ hird-line in 28%. The percentage of patients achieving low disease activity (BASDAI<4) increased from 9% at baseline to 48% at month 6 and was maintained (49%) up to month 24. The greatest improvement in BASDAI was observed in naïve patients (month 6: -2.6; month 24: -3.7), followed by second-line (month 6: -1.9; month 24: -3.1) and ≥ third-line (month 6: -1.3; month 24: -2.3) patients. Reductions in mean pain VAS (-23.3; -31.9), ptGA (-25.1; -31.9) and phGA (-25.1; -31) were also observed at 6 and 24 months. Secukinumab showed an overall 12-months persistence rate of 70% (95% confidence interval [CI]: 63-77%) and a 24-months persistence rate of 58% (95% CI, 51-66%). Patients receiving first-line secukinumab had the highest 24-months persistence rate (p = 0.05). Conclusion: Secukinumab improved disease activity in axSpA patients, especially in naive, and second-line patients, which was accompanied by high persistence rates up to 24 months.
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The advent of long-read sequencing technologies has allowed the generation of multiple high-quality de novo genome assemblies for multiple species, including well-known model species such as Drosophila melanogaster. Genome assemblies for multiple individuals of the same species are key to discover the genetic diversity present in natural populations, especially the one generated by transposable elements, the most common type of structural variant. Despite the availability of multiple genomic data sets for D. melanogaster populations, we lack an efficient visual tool to display different genome assemblies simultaneously. In this work, we present DrosOmics, a population genomic-oriented browser currently containing 52 high-quality reference genomes of D. melanogaster, including annotations from a highly reliable set of transposable elements, and functional transcriptomics and epigenomics data for 26 genomes. DrosOmics is based on JBrowse 2, a highly scalable platform, which allows the visualization of multiple assemblies at once, key to unraveling structural and functional features of D. melanogaster natural populations. DrosOmics is an open access browser and is freely available at http://gonzalezlab.eu/drosomics.
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Elementos Transponibles de ADN , Drosophila melanogaster , Animales , Drosophila melanogaster/genética , GenómicaRESUMEN
PURPOSE: Phosphatase and tensin homolog (PTEN) loss of function occurs in approximately 50% of patients with metastatic castrate-resistant prostate cancer (mCRPC), and is associated with poor prognosis and responsiveness to standard-of-care therapies and immune checkpoint inhibitors. While PTEN loss of function hyperactivates PI3K signaling, combinatorial PI3K/AKT pathway and androgen deprivation therapy (ADT) has demonstrated limited anticancer efficacy in clinical trials. Here, we aimed to elucidate mechanism(s) of resistance to ADT/PI3K-AKT axis blockade, and to develop rational combinatorial strategies to effectively treat this molecular subset of mCRPC. EXPERIMENTAL DESIGN: Prostate-specific PTEN/p53-deficient genetically engineered mice (GEM) with established 150-200 mm3 tumors, as assessed by ultrasound, were treated with either ADT (degarelix), PI3K inhibitor (copanlisib), or anti-PD-1 antibody (aPD-1), as single agents or their combinations, and tumors were monitored by MRI and harvested for immune, transcriptomic, and proteomic profiling, or ex vivo co-culture studies. Single-cell RNA sequencing on human mCRPC samples was performed using 10X Genomics platform. RESULTS: Coclinical trials in PTEN/p53-deficient GEM revealed that recruitment of PD-1-expressing tumor-associated macrophages (TAM) thwarts ADT/PI3Ki combination-induced tumor control. The addition of aPD-1 to ADT/PI3Ki combination led to TAM-dependent approximately 3-fold increase in anticancer responses. Mechanistically, decreased lactate production from PI3Ki-treated tumor cells suppressed histone lactylation within TAM, resulting in their anticancer phagocytic activation, which was augmented by ADT/aPD-1 treatment and abrogated by feedback activation of Wnt/ß-catenin pathway. Single-cell RNA-sequencing analysis in mCRPC patient biopsy samples revealed a direct correlation between high glycolytic activity and TAM phagocytosis suppression. CONCLUSIONS: Immunometabolic strategies that reverse lactate and PD-1-mediated TAM immunosuppression, in combination with ADT, warrant further investigation in patients with PTEN-deficient mCRPC.
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Neoplasias de la Próstata Resistentes a la Castración , Masculino , Animales , Ratones , Humanos , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Neoplasias de la Próstata Resistentes a la Castración/genética , Neoplasias de la Próstata Resistentes a la Castración/patología , Proteína p53 Supresora de Tumor/genética , Proteínas Proto-Oncogénicas c-akt , Antagonistas de Andrógenos/uso terapéutico , Ácido Láctico , Fosfatidilinositol 3-Quinasas , Proteómica , Vía de Señalización Wnt , Terapia de Inmunosupresión , Macrófagos/patología , Fosfohidrolasa PTEN/genéticaRESUMEN
Resumen Objetivo: Sintetizar y valorar críticamente las recomendaciones sobre manejo neurocognitivo del paciente con cardiopatía congénita presentadas en guías de práctica clínica y declaraciones científicas. Método: Revisión sistemática de recomendaciones de práctica (PROSPERO CRD42020205202). Se realizó una búsqueda en PubMed, SCOPUS, Ovid/Cochrane, y LILACS y se revisaron repositorios de sociedades científicas y referencias de los documentos incluidos. La valoración crítica se hizo mediante el AGREE-II (escenario ideal) para las guías y declaraciones, y mediante el AGREE-REX para las recomendaciones (escenarios ideal y local). Se presentan la matriz de recomendaciones y el análisis de barreras potenciales para su implementación en Colombia. Resultados: Se incluyeron 18 recomendaciones relacionadas. La media en el AGREE-II fue 89.6. La media en el AGREE-REX fue 90.1 en el escenario ideal y 69.9 en el escenario local. Las recomendaciones incluidas se centran en vigilancia, tamizaje, evaluación y consejería; no se identificaron recomendaciones sobre intervención neurocognitiva. Las principales barreras de implementación en Colombia son la no disposición a pagar por parte del sistema de salud y la ausencia de oferta integral de atención para el manejo neurocognitivo en cardiopatía congénita. Conclusión: Las recomendaciones identificadas podrían ser adaptadas en una guía de práctica colombiana, realizando modificaciones en reconocimiento del contexto local.
Abstract Objective: To synthesize and critically assess the recommendations on neurocognitive management of patients with congenital heart disease presented in clinical practice guidelines and scientific statements. Method: A systematic review of practice recommendations (PROSPERO CRD42020205202). PubMed, SCOPUS, Ovid/Cochrane, and LILACS were searched, and repositories of scientific societies and references of included documents were reviewed. Critical appraisal was performed using the AGREE-II (ideal scenario) for the guidelines and statements, and recommendations were assessed using the AGREE-REX (ideal and local scenarios). A matrix of recommendations and analysis of potential barriers for its implementation in Colombia is presented. Results: Eighteen related recommendations were included. The average AGREE-II was 89.6. The average AGREE-REX was 90.1 in the ideal setting and 69.9 in the local setting. The included recommendations focus on surveillance, screening, evaluation, and counseling; no recommendations on neurocognitive intervention were identified. The main implementation barriers in Colombia are the unwillingness to pay on the part of the health system and the absence of a comprehensive health care offer for neurocognitive management in congenital heart disease. Conclusion: The identified recommendations could be adapted into a Colombian practice guideline, making modifications that recognize the local context.
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Transposable elements (TEs), also known as transposons, are repetitive DNA sequences, present in virtually all organisms, that can move from one genomic position to another. TEs can be a source of mutations with important consequences for organisms. Despite their interest, its repetitive nature has made their study very challenging. However, the emergence of new sequencing technologies that allow obtaining long-read sequences, has improved the in silico de novo detection and annotation of TEs. The de novo annotation of TEs has already been performed in several organisms including the fruit fly Drosophila melanogaster. Yet, experimental validation can be used to confirm the presence of TEs in specific D. melanogaster natural populations. Here, we present a step-by-step protocol to experimentally validate by polymerase chain reaction (PCR) the presence and/or absence of TEs in natural populations of D. melanogaster. This detailed protocol has been implemented in the participant high schools of the Citizen Fly Lab activity that is part of the international citizen science project Melanogaster: Catch the Fly! ( https://melanogaster.eu ). Specifically, the students collaborate with the scientists of the European Drosophila Population Genomics Consortium (DrosEU) in the experimental validation of new genetic variants, previously identified using bioinformatic techniques.
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Elementos Transponibles de ADN , Drosophila melanogaster , Humanos , Animales , Elementos Transponibles de ADN/genética , Drosophila melanogaster/genética , Reacción en Cadena de la Polimerasa , Drosophila , GenómicaRESUMEN
BACKGROUND: Escalation in industrialization and anthropogenic activity have resulted in an increase of pollutants released into the environment. Of these pollutants, heavy metals such as copper are particularly concerning due to their bio-accumulative nature. Due to its highly heterogeneous distribution and its dual nature as an essential micronutrient and toxic element, the genetic basis of copper tolerance is likely shaped by a complex interplay of genetic and environmental factors. RESULTS: In this study, we utilized the natural variation present in multiple populations of Drosophila melanogaster collected across Europe to screen for variation in copper tolerance. We found that latitude and the degree of urbanization at the collection sites, rather than any other combination of environmental factors, were linked to copper tolerance. While previously identified copper-related genes were not differentially expressed in tolerant vs. sensitive strains, genes involved in metabolism, reproduction, and protease induction contributed to the differential stress response. Additionally, the greatest transcriptomic and physiological responses to copper toxicity were seen in the midgut, where we found that preservation of gut acidity is strongly linked to greater tolerance. Finally, we identified transposable element insertions likely to play a role in copper stress response. CONCLUSIONS: Overall, by combining genome-wide approaches with environmental association analysis, and functional analysis of candidate genes, our study provides a unique perspective on the genetic and environmental factors that shape copper tolerance in natural D. melanogaster populations and identifies new genes, transposable elements, and physiological traits involved in this complex phenotype.
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Cobre , Drosophila , Animales , Cobre/toxicidad , Drosophila melanogaster/genética , Genómica , Europa (Continente)RESUMEN
The McDonald and Kreitman test is one of the most powerful and widely used methods to detect and quantify recurrent natural selection in DNA sequence data. One of its main limitations is the underestimation of positive selection due to the presence of slightly deleterious variants segregating at low frequencies. Although several approaches have been developed to overcome this limitation, most of them work on gene pooled analyses. Here, we present the imputed McDonald and Kreitman test (impMKT), a new straightforward approach for the detection of positive selection and other selection components of the distribution of fitness effects at the gene level. We compare imputed McDonald and Kreitman test with other widely used McDonald and Kreitman test approaches considering both simulated and empirical data. By applying imputed McDonald and Kreitman test to humans and Drosophila data at the gene level, we substantially increase the statistical evidence of positive selection with respect to previous approaches (e.g. by 50% and 157% compared with the McDonald and Kreitman test in Drosophila and humans, respectively). Finally, we review the minimum number of genes required to obtain a reliable estimation of the proportion of adaptive substitution (α) in gene pooled analyses by using the imputed McDonald and Kreitman test compared with other McDonald and Kreitman test implementations. Because of its simplicity and increased power to detect recurrent positive selection on genes, we propose the imputed McDonald and Kreitman test as the first straightforward approach for testing specific evolutionary hypotheses at the gene level. The software implementation and population genomics data are available at the web-server imkt.uab.cat.
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Evolución Biológica , Selección Genética , Animales , Drosophila/genética , Evolución Molecular , Humanos , Metagenómica , Programas InformáticosRESUMEN
PURPOSE: To identify the optimal threshold in 18F-fluoromisonidazole (FMISO) PET images to accurately locate tumor hypoxia by using electron paramagnetic resonance imaging (pO2 EPRI) as ground truth for hypoxia, defined by pO2 [Formula: see text] 10 mmHg. METHODS: Tumor hypoxia images in mouse models of SCCVII squamous cell carcinoma (n = 16) were acquired in a hybrid PET/EPRI imaging system 2 h post-injection of FMISO. T2-weighted MRI was used to delineate tumor and muscle tissue. Dynamic contrast enhanced (DCE) MRI parametric images of Ktrans and ve were generated to model tumor vascular properties. Images from PET/EPR/MRI were co-registered and resampled to isotropic 0.5 mm voxel resolution for analysis. PET images were converted to standardized uptake value (SUV) and tumor-to-muscle ratio (TMR) units. FMISO uptake thresholds were evaluated using receiver operating characteristic (ROC) curve analysis to find the optimal FMISO threshold and unit with maximum overall hypoxia similarity (OHS) with pO2 EPRI, where OHS = 1 shows perfect overlap and OHS = 0 shows no overlap. The means of dice similarity coefficient, normalized Hausdorff distance, and accuracy were used to define the OHS. Monotonic relationships between EPRI/PET/DCE-MRI were evaluated with the Spearman correlation coefficient ([Formula: see text]) to quantify association of vasculature on hypoxia imaged with both FMISO PET and pO2 EPRI. RESULTS: FMISO PET thresholds to define hypoxia with maximum OHS (both OHS = 0.728 [Formula: see text] 0.2) were SUV [Formula: see text] 1.4 [Formula: see text] SUVmean and SUV [Formula: see text] 0.6 [Formula: see text] SUVmax. Weak-to-moderate correlations (|[Formula: see text]|< 0.70) were observed between PET/EPRI hypoxia images with vascular permeability (Ktrans) or fractional extracellular-extravascular space (ve) from DCE-MRI. CONCLUSION: This is the first in vivo comparison of FMISO uptake with pO2 EPRI to identify the optimal FMISO threshold to define tumor hypoxia, which may successfully direct hypoxic tumor boosts in patients, thereby enhancing tumor control.
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Carcinoma de Células Escamosas , Hipoxia Tumoral , Animales , Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/patología , Hipoxia de la Célula , Espectroscopía de Resonancia por Spin del Electrón , Hipoxia/diagnóstico por imagen , Ratones , Misonidazol/análogos & derivados , Tomografía de Emisión de Positrones/métodos , Radiofármacos , Tomografía Computarizada por Rayos XRESUMEN
Adaptive challenges that humans faced as they expanded across the globe left specific molecular footprints that can be decoded in our today's genomes. Different sets of metrics are used to identify genomic regions that have undergone selection. However, there are fewer methods capable of pinpointing the allele ultimately responsible for this selection. Here, we present PopHumanVar, an interactive online application that is designed to facilitate the exploration and thorough analysis of candidate genomic regions by integrating both functional and population genomics data currently available. PopHumanVar generates useful summary reports of prioritized variants that are putatively causal of recent selective sweeps. It compiles data and graphically represents different layers of information, including natural selection statistics, as well as functional annotations and genealogical estimations of variant age, for biallelic single nucleotide variants (SNVs) of the 1000 Genomes Project phase 3. Specifically, PopHumanVar amasses SNV-based information from GEVA, SnpEFF, GWAS Catalog, ClinVar, RegulomeDB and DisGeNET databases, as well as accurate estimations of iHS, nSL and iSAFE statistics. Notably, PopHumanVar can successfully identify known causal variants of frequently reported candidate selection regions, including EDAR in East-Asians, ACKR1 (DARC) in Africans and LCT/MCM6 in Europeans. PopHumanVar is open and freely available at https://pophumanvar.uab.cat.
Asunto(s)
Bases de Datos Genéticas , Genoma Humano/genética , Selección Genética/genética , Programas Informáticos , Adaptación Fisiológica/genética , Biología Computacional , Genómica , Humanos , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
Drosophila melanogaster is a leading model in population genetics and genomics, and a growing number of whole-genome data sets from natural populations of this species have been published over the last years. A major challenge is the integration of disparate data sets, often generated using different sequencing technologies and bioinformatic pipelines, which hampers our ability to address questions about the evolution of this species. Here we address these issues by developing a bioinformatics pipeline that maps pooled sequencing (Pool-Seq) reads from D. melanogaster to a hologenome consisting of fly and symbiont genomes and estimates allele frequencies using either a heuristic (PoolSNP) or a probabilistic variant caller (SNAPE-pooled). We use this pipeline to generate the largest data repository of genomic data available for D. melanogaster to date, encompassing 271 previously published and unpublished population samples from over 100 locations in >20 countries on four continents. Several of these locations have been sampled at different seasons across multiple years. This data set, which we call Drosophila Evolution over Space and Time (DEST), is coupled with sampling and environmental metadata. A web-based genome browser and web portal provide easy access to the SNP data set. We further provide guidelines on how to use Pool-Seq data for model-based demographic inference. Our aim is to provide this scalable platform as a community resource which can be easily extended via future efforts for an even more extensive cosmopolitan data set. Our resource will enable population geneticists to analyze spatiotemporal genetic patterns and evolutionary dynamics of D. melanogaster populations in unprecedented detail.