Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74.262
Filtrar
1.
Int J Mol Sci ; 22(10)2021 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-34066274

RESUMEN

Polyamines are ubiquitous, low-molecular-weight aliphatic compounds, present in living organisms and essential for cell growth and differentiation. Copper amine oxidases (CuAOs) oxidize polyamines to aminoaldehydes releasing ammonium and hydrogen peroxide, which participates in the complex network of reactive oxygen species acting as signaling molecules involved in responses to biotic and abiotic stresses. CuAOs have been identified and characterized in different plant species, but the most extensive study on a CuAO gene family has been carried out in Arabidopsis thaliana. Growing attention has been devoted in the last years to the investigation of the CuAO expression pattern during development and in response to an array of stress and stress-related hormones, events in which recent studies have highlighted CuAOs to play a key role by modulation of a multilevel phenotypic plasticity expression. In this review, the attention will be focused on the involvement of different AtCuAOs in the IAA/JA/ABA signal transduction pathways which mediate stress-induced phenotypic plasticity events.


Asunto(s)
Adaptación Fisiológica , Amina Oxidasa (conteniendo Cobre)/metabolismo , Regulación de la Expresión Génica de las Plantas , Hormonas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Plantas/enzimología , Estrés Fisiológico , Plantas/inmunología , Plantas/metabolismo
2.
Int J Mol Sci ; 22(10)2021 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-34068993

RESUMEN

The human cathelicidin LL-37 is a multifunctional peptide of the human innate immune system. Among the various functions of LL-37, its antimicrobial activity is important in controlling the microorganisms of the human body. The target molecules of LL-37 in bacteria include membrane lipids, lipopolysaccharides (LPS), lipoteichoic acid (LTA), proteins, DNA and RNA. In this mini-review, we summarize the entity of LL-37 structural data determined over the last 15 years and specifically discuss features implicated in the interactions with lipid-like molecules. For this purpose, we discuss partial and full-length structures of LL-37 determined in the presence of membrane-mimicking detergents. This constantly growing structural database is now composed of monomers, dimers, tetramers, and fiber-like structures. The diversity of these structures underlines an unexpected plasticity and highlights the conformational and oligomeric adaptability of LL-37 necessary to target different molecular scaffolds. The recent co-crystal structures of LL-37 in complex with detergents are particularly useful to understand how these molecules mimic lipids and LPS to induce oligomerization and fibrillation. Defined detergent binding sites provide deep insights into a new class of peptide scaffolds, widening our view on the fascinating world of the LL-37 structural factotum. Together, the new structures in their evolutionary context allow for the assignment of functionally conserved residues in oligomerization and target interactions. Conserved phenylalanine and arginine residues primarily mediate those interactions with lipids and LPS. The interactions with macromolecules such as proteins or DNA remain largely unexplored and open a field for future studies aimed at structures of LL-37 complexes. These complexes will then allow for the structure-based rational design of LL-37-derived peptides with improved antibiotic properties.


Asunto(s)
Adaptación Fisiológica , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Bacterias/química , Bacterias/efectos de los fármacos , Membrana Celular/química , Lípidos/química , Bacterias/metabolismo , Humanos
3.
Nat Commun ; 12(1): 3376, 2021 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-34099660

RESUMEN

Phenotypic plasticity is the variation in phenotype that a single genotype can produce in different environments and, as such, is an important component of individual fitness. However, whether the effect of new mutations, and hence evolution, depends on the direction of plasticity remains controversial. Here, we identify the cis-acting modifications that have reshaped gene expression in response to dehydration stress in three Arabidopsis species. Our study shows that the direction of effects of most cis-regulatory variants differentiating the response between A. thaliana and the sister species A. lyrata and A. halleri depends on the direction of pre-existing plasticity in gene expression. A comparison of the rate of cis-acting variant accumulation in each lineage indicates that the selective forces driving adaptive evolution in gene expression favors regulatory changes that magnify the stress response in A. lyrata. The evolutionary constraints measured on the amino-acid sequence of these genes support this interpretation. In contrast, regulatory changes that mitigate the plastic response to stress evolved more frequently in A. halleri. Our results demonstrate that pre-existing plasticity may be a stepping stone for adaptation, but its selective remodeling differs between lineages.


Asunto(s)
Adaptación Fisiológica/genética , Arabidopsis/genética , Evolución Molecular , Regulación de la Expresión Génica de las Plantas , Elementos Reguladores de la Transcripción/genética , Sequías , Genes de Plantas , Fitomejoramiento , Especificidad de la Especie
4.
Nat Commun ; 12(1): 3457, 2021 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-34103505

RESUMEN

Bacillus subtilis is a soil bacterium that is competent for natural transformation. Genetically distinct B. subtilis swarms form a boundary upon encounter, resulting in killing of one of the strains. This process is mediated by a fast-evolving kin discrimination (KD) system consisting of cellular attack and defence mechanisms. Here, we show that these swarm antagonisms promote transformation-mediated horizontal gene transfer between strains of low relatedness. Gene transfer between interacting non-kin strains is largely unidirectional, from killed cells of the donor strain to surviving cells of the recipient strain. It is associated with activation of a stress response mediated by sigma factor SigW in the donor cells, and induction of competence in the recipient strain. More closely related strains, which in theory would experience more efficient recombination due to increased sequence homology, do not upregulate transformation upon encounter. This result indicates that social interactions can override mechanistic barriers to horizontal gene transfer. We hypothesize that KD-mediated competence in response to the encounter of distinct neighbouring strains could maximize the probability of efficient incorporation of novel alleles and genes that have proved to function in a genomically and ecologically similar context.


Asunto(s)
Bacillus subtilis/genética , Transferencia de Gen Horizontal , Adaptación Fisiológica , Membrana Celular/metabolismo , ADN Bacteriano/genética , Genoma Bacteriano , Mutación/genética , Nucleótidos/genética , Recombinación Genética/genética , Estrés Fisiológico , Transformación Genética , Regulación hacia Arriba
5.
Int J Mol Sci ; 22(11)2021 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-34071053

RESUMEN

Under stressful conditions, the hypothalamic-pituitary-adrenal (HPA) axis acts to promote transitory physiological adaptations that are often resolved after the stressful stimulus is no longer present. In addition to corticosteroids (e.g., cortisol), the neurosteroid allopregnanolone (3α,5α-tetrahydroprogesterone, 3α-hydroxy-5α-pregnan-20-one) participates in negative feedback mechanisms that restore homeostasis. Chronic, repeated exposure to stress impairs the responsivity of the HPA axis and dampens allopregnanolone levels, participating in the etiopathology of psychiatric disorders, such as major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). MDD and PTSD patients present abnormalities in the HPA axis regulation, such as altered cortisol levels or failure to suppress cortisol release in the dexamethasone suppression test. Herein, we review the neurophysiological role of allopregnanolone both as a potent and positive GABAergic neuromodulator but also in its capacity of inhibiting the HPA axis. The allopregnanolone function in the mechanisms that recapitulate stress-induced pathophysiology, including MDD and PTSD, and its potential as both a treatment target and as a biomarker for these disorders is discussed.


Asunto(s)
Trastorno Depresivo Mayor/fisiopatología , Sistema Hipotálamo-Hipofisario/fisiopatología , Sistema Hipófiso-Suprarrenal/fisiopatología , Pregnanolona/fisiología , Adaptación Fisiológica , Animales , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Enfermedad Crónica , Corticosterona/metabolismo , Trastorno Depresivo Mayor/tratamiento farmacológico , Retroalimentación Fisiológica , Femenino , Agonistas de Receptores de GABA-A/uso terapéutico , Humanos , Masculino , Modelos Biológicos , Pregnanolona/biosíntesis , Receptores de GABA-A/fisiología , Caracteres Sexuales , Trastornos por Estrés Postraumático/fisiopatología , Estrés Fisiológico , Estrés Psicológico/fisiopatología , Estrés Psicológico/psicología , Ácido gamma-Aminobutírico/fisiología
6.
Int J Mol Sci ; 22(11)2021 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-34071490

RESUMEN

The Pv11, an insect cell line established from the midge Polypedilum vanderplanki, is capable of extreme hypometabolic desiccation tolerance, so-called anhydrobiosis. We previously discovered that heat shock factor 1 (HSF1) contributes to the acquisition of desiccation tolerance by Pv11 cells, but the mechanistic details have yet to be elucidated. Here, by analyzing the gene expression profiles of newly established HSF1-knockout and -rescue cell lines, we show that HSF1 has a genome-wide effect on gene regulation in Pv11. The HSF1-knockout cells exhibit a reduced desiccation survival rate, but this is completely restored in HSF1-rescue cells. By comparing mRNA profiles of the two cell lines, we reveal that HSF1 induces anhydrobiosis-related genes, especially genes encoding late embryogenesis abundant proteins and thioredoxins, but represses a group of genes involved in basal cellular processes, thus promoting an extreme hypometabolism state in the cell. In addition, HSF1 binding motifs are enriched in the promoters of anhydrobiosis-related genes and we demonstrate binding of HSF1 to these promoters by ChIP-qPCR. Thus, HSF1 directly regulates the transcription of anhydrobiosis-related genes and consequently plays a pivotal role in the induction of anhydrobiotic ability in Pv11 cells.


Asunto(s)
Adaptación Fisiológica/genética , Chironomidae/genética , Desecación , Regulación de la Expresión Génica , Estudio de Asociación del Genoma Completo/métodos , Factores de Transcripción del Choque Térmico/genética , Proteínas de Insectos/genética , Animales , Línea Celular , Chironomidae/citología , Análisis por Conglomerados , Perfilación de la Expresión Génica/métodos
9.
Int J Mol Sci ; 22(11)2021 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-34072612

RESUMEN

The BAG proteins are a family of multi-functional co-chaperones. In plants, BAG proteins were found to play roles both in abiotic and biotic stress tolerance. However, the function of Arabidopsis BAG2 remains largely unknown, whereas BAG6 is required for plants' defense to pathogens, although it remains unknown whether BAG6 is involved in plants' tolerance to abiotic stresses. Here, we show that both BAG2 and BAG6 are expressed in various tissues and are upregulated by salt, mannitol, and heat treatments and by stress-related hormones including ABA, ethylene, and SA. Germination of bag2, bag6 and bag2 bag6 seeds is less sensitive to ABA compared to the wild type (WT), whereas BAG2 and BAG6 overexpression lines are hypersensitive to ABA. bag2, bag6, and bag2 bag6 plants show higher survival rates than WT in drought treatment but display lower survival rates in heat-stress treatment. Consistently, these mutants showed differential expression of several stress- and ABA-related genes such as RD29A, RD29B, NCED3 and ABI4 compared to the WT. Furthermore, these mutants exhibit lower levels of ROS after drought and ABA treatment but higher ROS accumulation after heat treatment than the WT. These results suggest that BAG2 and BAG6 are negatively involved in drought stress but play a positive role in heat stress in Arabidopsis.


Asunto(s)
Adaptación Fisiológica , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas Mitocondriales/genética , Chaperonas Moleculares/genética , Proteínas Nucleares/genética , Estrés Fisiológico , Proteínas de Arabidopsis/metabolismo , Sequías , Proteínas Mitocondriales/metabolismo , Chaperonas Moleculares/metabolismo , Mutación , Proteínas Nucleares/metabolismo , Desarrollo de la Planta/genética , Reguladores del Crecimiento de las Plantas/metabolismo , Especies Reactivas de Oxígeno/metabolismo
10.
Nat Commun ; 12(1): 3282, 2021 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-34078900

RESUMEN

Bacterial processes necessary for adaption to stressful host environments are potential targets for new antimicrobials. Here, we report large-scale transcriptomic analyses of 32 human bacterial pathogens grown under 11 stress conditions mimicking human host environments. The potential relevance of the in vitro stress conditions and responses is supported by comparisons with available in vivo transcriptomes of clinically important pathogens. Calculation of a probability score enables comparative cross-microbial analyses of the stress responses, revealing common and unique regulatory responses to different stresses, as well as overlapping processes participating in different stress responses. We identify conserved and species-specific 'universal stress responders', that is, genes showing altered expression in multiple stress conditions. Non-coding RNAs are involved in a substantial proportion of the responses. The data are collected in a freely available, interactive online resource (PATHOgenex).


Asunto(s)
Regulación Bacteriana de la Expresión Génica , Bacterias Gramnegativas/genética , Bacterias Grampositivas/genética , ARN Bacteriano/genética , Estrés Fisiológico/genética , Transcriptoma , Adaptación Fisiológica/genética , Atlas como Asunto , Bases de Datos Genéticas , Perfilación de la Expresión Génica , Genes Bacterianos , Bacterias Gramnegativas/clasificación , Bacterias Gramnegativas/metabolismo , Bacterias Gramnegativas/patogenicidad , Bacterias Grampositivas/clasificación , Bacterias Grampositivas/metabolismo , Bacterias Grampositivas/patogenicidad , Interacciones Microbiota-Huesped/genética , Humanos , Internet , Microbiota/genética , Filogenia , ARN Bacteriano/metabolismo
11.
BMC Genomics ; 22(1): 388, 2021 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-34039278

RESUMEN

BACKGROUND: Elucidating the effects of geography and selection on genetic variation is critical for understanding the relative importance of adaptation in driving differentiation and identifying the environmental factors underlying its occurrence. Adaptive genetic variation is common in tree species, especially widely distributed long-lived species. Pseudotaxus chienii can occupy diverse habitats with environmental heterogeneity and thus provides an ideal material for investigating the process of population adaptive evolution. Here, we characterize genetic and expression variation patterns and investigate adaptive genetic variation in P. chienii populations. RESULTS: We generated population transcriptome data and identified 13,545 single nucleotide polymorphisms (SNPs) in 5037 unigenes across 108 individuals from 10 populations. We observed lower nucleotide diversity (π = 0.000701) among the 10 populations than observed in other gymnosperms. Significant negative correlations between expression diversity and nucleotide diversity in eight populations suggest that when the species adapts to the surrounding environment, gene expression and nucleotide diversity have a reciprocal relationship. Genetic structure analyses indicated that each distribution region contains a distinct genetic group, with high genetic differentiation among them due to geographical isolation and local adaptation. We used FST outlier, redundancy analysis, and latent factor mixed model methods to detect molecular signatures of local adaptation. We identified 244 associations between 164 outlier SNPs and 17 environmental variables. The mean temperature of the coldest quarter, soil Fe and Cu contents, precipitation of the driest month, and altitude were identified as the most important determinants of adaptive genetic variation. Most candidate unigenes with outlier signatures were related to abiotic and biotic stress responses, and the monoterpenoid biosynthesis and ubiquitin-mediated proteolysis KEGG pathways were significantly enriched in certain populations and deserve further attention in other long-lived trees. CONCLUSIONS: Despite the strong population structure in P. chienii, genomic data revealed signatures of divergent selection associated with environmental variables. Our research provides SNPs, candidate unigenes, and biological pathways related to environmental variables to facilitate elucidation of the genetic variation in P. chienii in relation to environmental adaptation. Our study provides a promising tool for population genomic analyses and insights into the molecular basis of local adaptation.


Asunto(s)
Taxaceae , Transcriptoma , Adaptación Fisiológica/genética , Biología Computacional , Flujo Genético , Genética de Población , Humanos , Polimorfismo de Nucleótido Simple
12.
J Environ Manage ; 291: 112583, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33932834

RESUMEN

Climate change increases risks to natural and human systems. Green infrastructure (GI) has been increasingly recognized as a promising nature-based solution for climate change adaptation, mitigation, and other societal objectives for sustainable development. Although the climate contribution of GI has been extensively addressed in the literature, the linkages between the climate benefits and associated co-benefits and trade-offs remain unclear. We systematically reviewed the evidence from 141 papers, focusing on their climate benefits, relevant co-benefits and trade-offs, and the GI types that provide such climate (co-)benefits. This study presents a comprehensive overview of the links between climate benefits, co-benefits and types of GI, categorized along a green-grey continuum so that researchers/practitioners can find information according to their topic of interest. We further provide an analysis of trade-offs between various GI benefits. 'Bundles' of major co-benefits and trade-offs for each climate benefit can be identified with recommendations for strategies to maximize benefits and minimize trade-offs. To promote climate-resilient pathways through GI, it is crucial for decision-makers to identify opportunities to deliver multiple ecosystem services and benefits while recognizing disservices and trade-offs that need to be avoided or managed.


Asunto(s)
Cambio Climático , Ecosistema , Aclimatación , Adaptación Fisiológica , Conservación de los Recursos Naturales , Humanos
13.
J Environ Manage ; 291: 112727, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33957417

RESUMEN

Unceasing climate change and anthropogenic impacts on coral reefs worldwide lead the needs for augmenting adaptive potential of corals. Currently, the most successful approach for restoring degraded reefs is 'coral gardening', where corals are farmed in underwater nurseries, then outplanted to damaged reefs. Dealing with enhanced coral adaptation, the 'coral gardening' approach is conceptually structured here within a hierarchical list of five encircling tiers that include all restoration activities, focusing on the nursery phase. Each tier encompasses all the activities performed in the levels below it hierarchically. The first is the 'coral mariculture' tier, followed by the 'ecological engineering' tier. The third is the adaptation-based reef restoration (ABRR) tier, preceding the fourth ('ecosystem seascape') and the fifth ('ecosystem services') tiers. The ABRR tier is further conceptualized and its constituent five classes (phenotypic plasticity, assisted migration, epigenetics, coral chimerism, holobiont modification) are detailed. It is concluded that the nursery phase of the 'gardening' tenet may further serve as a platform to enhance the adaptation capacities of corals to climate change through the five ABBR classes. Employing the 'gardening' tiers in reef restoration without considering ABRR will scarcely be able to meet global targets for healthy reef ecosystems in the future.


Asunto(s)
Antozoos , Adaptación Fisiológica , Animales , Cambio Climático , Conservación de los Recursos Naturales , Arrecifes de Coral , Ecosistema , Jardinería
14.
Nat Commun ; 12(1): 2643, 2021 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-33976118

RESUMEN

Prediction of future sensory input based on past sensory information is essential for organisms to effectively adapt their behavior in dynamic environments. Humans successfully predict future stimuli in various natural settings. Yet, it remains elusive how the brain achieves effective prediction despite enormous variations in sensory input rate, which directly affect how fast sensory information can accumulate. We presented participants with acoustic sequences capturing temporal statistical regularities prevalent in nature and investigated neural mechanisms underlying predictive computation using MEG. By parametrically manipulating sequence presentation speed, we tested two hypotheses: neural prediction relies on integrating past sensory information over fixed time periods or fixed amounts of information. We demonstrate that across halved and doubled presentation speeds, predictive information in neural activity stems from integration over fixed amounts of information. Our findings reveal the neural mechanisms enabling humans to robustly predict dynamic stimuli in natural environments despite large sensory input rate variations.


Asunto(s)
Adaptación Fisiológica/fisiología , Algoritmos , Encéfalo/fisiología , Modelos Neurológicos , Red Nerviosa/fisiología , Sensación/fisiología , Estimulación Acústica , Adulto , Encéfalo/citología , Femenino , Humanos , Magnetoencefalografía/métodos , Masculino , Neuronas/fisiología , Desempeño Psicomotor/fisiología , Adulto Joven
15.
Biol Lett ; 17(5): 20200913, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33975485

RESUMEN

Antibiotic concentrations vary dramatically in the body and the environment. Hence, understanding the dynamics of resistance evolution along antibiotic concentration gradients is critical for predicting and slowing the emergence and spread of resistance. While it has been shown that increasing the concentration of an antibiotic slows resistance evolution, how adaptation to one antibiotic concentration correlates with fitness at other points along the gradient has not received much attention. Here, we selected populations of Escherichia coli at several points along a concentration gradient for three different antibiotics, asking how rapidly resistance evolved and whether populations became specialized to the antibiotic concentration they were selected on. Populations selected at higher concentrations evolved resistance more slowly but exhibited equal or higher fitness across the whole gradient. Populations selected at lower concentrations evolved resistance rapidly, but overall fitness in the presence of antibiotics was lower. However, these populations readily adapted to higher concentrations upon subsequent selection. Our results indicate that resistance management strategies must account not only for the rates of resistance evolution but also for the fitness of evolved strains.


Asunto(s)
Antibacterianos , Farmacorresistencia Bacteriana , Adaptación Fisiológica , Antibacterianos/farmacología , Escherichia coli , Mutación
16.
EBioMedicine ; 67: 103381, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33993052

RESUMEN

BACKGROUND: An ideal animal model to study SARS-coronavirus 2 (SARS-CoV-2) pathogenesis and evaluate therapies and vaccines should reproduce SARS-CoV-2 infection and recapitulate lung disease like those seen in humans. The angiotensin-converting enzyme 2 (ACE2) is a functional receptor for SARS-CoV-2, but mice are resistant to the infection because their ACE2 is incompatible with the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein . METHODS: SARS-CoV-2 was passaged in BALB/c mice to obtain mouse-adapted virus strain. Complete genome deep sequencing of different generations of viruses was performed to characterize the dynamics of the adaptive mutations in SARS-CoV-2. Indirect immunofluorescence analysis and Biolayer interferometry experiments determined the binding affinity of mouse-adapted SARS-CoV-2 WBP-1 RBD to mouse ACE2 and human ACE2. Finally, we tested whether TLR7/8 agonist Resiquimod (R848) could also inhibit the replication of WBP-1 in the mouse model. FINDINGS: The mouse-adapted strain WBP-1 showed increased infectivity in BALB/c mice and led to severe interstitial pneumonia. We characterized the dynamics of the adaptive mutations in SARS-CoV-2 and demonstrated that Q493K and Q498H in RBD significantly increased its binding affinity towards mouse ACE2. Additionally, the study tentatively found that the TLR7/8 agonist Resiquimod was able to protect mice against WBP-1 challenge. Therefore, this mouse-adapted strain is a useful tool to investigate COVID-19 and develop new therapies. INTERPRETATION: We found for the first time that the Q493K and Q498H mutations in the RBD of WBP-1 enhanced its interactive affinities with mACE2. The mouse-adapted SARS-CoV-2 provides a valuable tool for the evaluation of novel antiviral and vaccine strategies. This study also tentatively verified the antiviral activity of TLR7/8 agonist Resiquimod against SARS-CoV-2 in vitro and in vivo. FUNDING: This research was funded by the National Key Research and Development Program of China (2020YFC0845600) and Emergency Science and Technology Project of Hubei Province (2020FCA046) and Robert A. Welch Foundation (C-1565).


Asunto(s)
Sustitución de Aminoácidos , Enzima Convertidora de Angiotensina 2/metabolismo , COVID-19/virología , Imidazoles/administración & dosificación , SARS-CoV-2/patogenicidad , Glicoproteína de la Espiga del Coronavirus/metabolismo , Adaptación Fisiológica , Animales , Sitios de Unión , COVID-19/metabolismo , COVID-19/prevención & control , Células CACO-2 , Chlorocebus aethiops , Modelos Animales de Enfermedad , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Imidazoles/farmacología , Ratones , Ratones Endogámicos BALB C , SARS-CoV-2/genética , Pase Seriado , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Células Vero , Replicación Viral/efectos de los fármacos , Secuenciación Completa del Genoma
17.
Nat Commun ; 12(1): 2765, 2021 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-34035236

RESUMEN

We investigated the dynamic properties of the organism state fluctuations along individual aging trajectories in a large longitudinal database of CBC measurements from a consumer diagnostics laboratory. To simplify the analysis, we used a log-linear mortality estimate from the CBC variables as a single quantitative measure of the aging process, henceforth referred to as dynamic organism state indicator (DOSI). We observed, that the age-dependent population DOSI distribution broadening could be explained by a progressive loss of physiological resilience measured by the DOSI auto-correlation time. Extrapolation of this trend suggested that DOSI recovery time and variance would simultaneously diverge at a critical point of 120 - 150 years of age corresponding to a complete loss of resilience. The observation was immediately confirmed by the independent analysis of correlation properties of intraday physical activity levels fluctuations collected by wearable devices. We conclude that the criticality resulting in the end of life is an intrinsic biological property of an organism that is independent of stress factors and signifies a fundamental or absolute limit of human lifespan.


Asunto(s)
Adaptación Fisiológica/fisiología , Envejecimiento/fisiología , Biomarcadores/sangre , Longevidad/fisiología , Resiliencia Psicológica , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/psicología , Recuento de Células Sanguíneas/métodos , Femenino , Estado de Salud , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Adulto Joven
18.
Nat Commun ; 12(1): 3126, 2021 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-34035259

RESUMEN

Hybridization and polyploidization are powerful mechanisms of speciation. Hybrid speciation often coincides with whole-genome duplication (WGD) in eukaryotes. This suggests that WGD may allow hybrids to thrive by increasing fitness, restoring fertility and/or increasing access to adaptive mutations. Alternatively, it has been suggested that hybridization itself may trigger WGD. Testing these models requires quantifying the rate of WGD in hybrids without the confounding effect of natural selection. Here we show, by measuring the spontaneous rate of WGD of more than 1300 yeast crosses evolved under relaxed selection, that some genotypes or combinations of genotypes are more prone to WGD, including some hybrids between closely related species. We also find that higher WGD rate correlates with higher genomic instability and that WGD increases fertility and genetic variability. These results provide evidence that hybridization itself can promote WGD, which in turn facilitates the evolution of hybrids.


Asunto(s)
Duplicación de Gen , Genoma Fúngico/genética , Hibridación Genética , Saccharomyces/genética , Adaptación Fisiológica/genética , Diploidia , Evolución Molecular , Variación Genética/genética , Inestabilidad Genómica/genética , Tasa de Mutación , Filogenia , Poliploidía , Saccharomyces/clasificación , Saccharomyces cerevisiae/genética , Especificidad de la Especie
19.
BMC Ecol Evol ; 21(1): 97, 2021 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-34024284

RESUMEN

BACKGROUND: The stem-group of Ephemeroptera is phylogenetically important for understanding key steps in evolutionary history of early pterygote insects. However, these taxa have been mostly studied from the taxonomy point of view focused on the pattern of wing venation and often using only classical optical microscopy devices. In-depth studies on detailed morphology of the different body structures are scarcely performed, although the results are critical for elucidation of life history traits and their evolutionary pattern among the basal pterygotes. RESULTS: New information is presented on the morphology of two species of Misthodotes, which are stem-mayflies from the Early Permian. Based on new results obtained from a re-examination of the type specimens and supplementary material, we infer the life history traits of both the adult and larval stages of these Palaeozoic insects and reconsider previous interpretations. For the first time, we report the structure of the thoracic pleura and the articulation at the base of the wing in a stem-group of Ephemeroptera and compare them with those of extant mayflies. We also provide additional support for the systematic placement of investigated taxa and an amended diagnosis of the genus Misthodotes. CONCLUSIONS: Adult Misthodotes sharovi and Misthodotes zalesskyi had chewing mouthparts, which enabled them to scavenge or feed on plants. The wing apparatus was adapted for slow powered flapping flight and gliding, using long caudal filaments for steering. The wing base does not have rows of articulary sclerites as previously hypothesized for some Palaeozoic taxa but inflexible axilla similar to that found in modern mayflies. The structure of the thoracic pleura is also similar to that in the crown group of Ephemeroptera, while differences in the course of sutures may be explained by an evolutionary trend towards more powerful dorsoventral flying musculature and forewing-based flight (anteromotorism) in modern taxa. There is no evidence for swarming behaviour and mating in the air as occurs in modern mayflies as they had none of the associated morphological adaptations. Putative larvae of Misthodotes can not be unambiguously associated with the adults. They also exhibit some morphological specializations of Protereismatidae like 9 pairs of abdominal tracheal gills supporting their benthic lifestyle with legs adapted to burrowing.


Asunto(s)
Ephemeroptera , Adaptación Fisiológica , Animales , Evolución Biológica , Insectos , Alas de Animales
20.
Nat Commun ; 12(1): 3178, 2021 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-34039963

RESUMEN

Living systems formed and evolved under constraints that govern their interactions with the inorganic world. These interactions are definable using basic physico-chemical principles. Here, we formulate a comprehensive set of ten governing abiotic constraints that define possible quantitative metabolomes. We apply these constraints to a metabolic network of Escherichia coli that represents 90% of its metabolome. We show that the quantitative metabolomes allowed by the abiotic constraints are consistent with metabolomic and isotope-labeling data. We find that: (i) abiotic constraints drive the evolution of high-affinity phosphate transporters; (ii) Charge-, hydrogen- and magnesium-related constraints underlie transcriptional regulatory responses to osmotic stress; and (iii) hydrogen-ion and charge imbalance underlie transcriptional regulatory responses to acid stress. Thus, quantifying the constraints that the inorganic world imposes on living systems provides insights into their key characteristics, helps understand the outcomes of evolutionary adaptation, and should be considered as a fundamental part of theoretical biology and for understanding the constraints on evolution.


Asunto(s)
Adaptación Fisiológica , Escherichia coli/fisiología , Metaboloma/fisiología , Estrés Fisiológico , Ácidos/metabolismo , Evolución Biológica , Escherichia coli/química , Proteínas de Escherichia coli/análisis , Proteínas de Escherichia coli/metabolismo , Regulación de la Expresión Génica/fisiología , Hidrógeno/metabolismo , Magnesio/metabolismo , Redes y Vías Metabólicas/fisiología , Metabolómica , Ósmosis , Proteínas de Transporte de Fosfato/metabolismo , Fosfatos/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...