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1.
Wiad Lek ; 73(4): 679-683, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32731696

RESUMEN

OBJECTIVE: The aim: To determine the dynamics of adaptation resources and the level of psychological safety of the personality in service members of the National Guard of Ukraine who participated in combat operations in the East of Ukraine. PATIENTS AND METHODS: Materials and methods: To determine the peculiarities of military personnel adaptation to the combat activity, the "Adaptability-200" and "Disdaptability-45" methodologies were used. To determine the level of psychological safety of combatants we used "Diagnosis of psychological safety personality" and "Express diagnosis of psychological safety personality" Methodologies. The study was carried out during 2017, with 163 military participating. RESULTS: Results: Being 2-3 weeks in combat conditions, 54% service members revealed high, 32% - average level of adaptability, and in 14% of them signs of non-adaptability were detected. The data of adaptation resources of combatants correlates with the results of diagnostics of psychological safety of personality: in 43% of them high level, 42% - average and 15% - low level of psychological safety were revealed. CONCLUSION: Conclusions: The data obtained in the absolute majority of service members (86%) shows a good adaptability to combat conditions, and allows predicting adequate response to extreme conditions, high probability of preserving of the mental health and disability after the influence of vital factors.


Asunto(s)
Personal Militar , Adaptación Fisiológica , Humanos , Salud Mental , Personalidad , Ucrania
2.
Plant Mol Biol ; 103(4-5): 545-560, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32504260

RESUMEN

KEY MESSAGE: OsGTγ-2, a trihelix transcription factor, is a positive regulator of rice responses to salt stress by regulating the expression of ion transporters. Salinity stress seriously restricts rice growth and yield. Trihelix transcription factors (GT factors) specifically bind to GT elements and play a diverse role in plant morphological development and responses to abiotic stresses. In our previous study, we found that the GT-1 element (GAAAAA) is a key element in the salinity-induced OsRAV2 promoter. Here, we identified a rice OsGTγ family member, OsGTγ-2, which directly interacted with the GT-1 element in the OsRAV2 promoter. OsGTγ-2 specifically targeted the nucleus, was mainly expressed in roots, sheathes, stems and seeds, and was induced by salinity, osmotic and oxidative stresses and abscisic acid (ABA). The seed germination rate, seedling growth and survival rate under salinity stress was improved in OsGTγ-2 overexpressing lines (PZmUbi::OsGTγ-2). In contrast, CRISPR/Cas9-mediated OsGTγ-2 knockout lines (osgtγ-2) showed salt-hypersensitive phenotypes. In response to salt stress, different Na+ and K+ acclamation patterns were observed in PZmUbi::OsGTγ-2 lines and osgtγ-2 plants were observed. The molecular mechanism of OsGTγ-2 in rice salt adaptation was also investigated. Several major genes responsible for ion transporting, such as the OsHKT2; 1, OsHKT1; 3 and OsNHX1 were transcriptionally regulated by OsGTγ-2. A subsequent yeast one-hybrid assay and EMSA indicated that OsGTγ-2 directly interacted with the promoters of OsHKT2; 1, OsNHX1 and OsHKT1; 3. Taken together, these results suggest that OsGTγ-2 is an important positive regulator involved in rice responses to salt stress and suggest a potential role for OsGTγ-2 in regulating salinity adaptation in rice.


Asunto(s)
Aclimatación/fisiología , Proteínas de Unión al ADN/metabolismo , Oryza/fisiología , Estrés Salino/fisiología , Tolerancia a la Sal/genética , Factores de Transcripción/metabolismo , Ácido Abscísico/metabolismo , Aclimatación/genética , Adaptación Fisiológica , Sistemas CRISPR-Cas , Proteínas de Transporte de Catión/metabolismo , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Oryza/crecimiento & desarrollo , Desarrollo de la Planta , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo , Salinidad , Plantones/genética , Semillas/metabolismo , Sodio/metabolismo , Intercambiadores de Sodio-Hidrógeno/metabolismo , Estrés Fisiológico/genética , Simportadores/metabolismo , Factores de Transcripción/genética
3.
Science ; 368(6498): 1495-1499, 2020 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-32587022

RESUMEN

Although sled dogs are one of the most specialized groups of dogs, their origin and evolution has received much less attention than many other dog groups. We applied a genomic approach to investigate their spatiotemporal emergence by sequencing the genomes of 10 modern Greenland sled dogs, an ~9500-year-old Siberian dog associated with archaeological evidence for sled technology, and an ~33,000-year-old Siberian wolf. We found noteworthy genetic similarity between the ancient dog and modern sled dogs. We detected gene flow from Pleistocene Siberian wolves, but not modern American wolves, to present-day sled dogs. The results indicate that the major ancestry of modern sled dogs traces back to Siberia, where sled dog-specific haplotypes of genes that potentially relate to Arctic adaptation were established by 9500 years ago.


Asunto(s)
Adaptación Fisiológica/genética , Perros/genética , Animales , Apolipoproteínas/genética , Regiones Árticas , Ácidos Grasos/metabolismo , Genoma , Groenlandia , Haplotipos , Proteínas de Transporte de Membrana Mitocondrial/genética , Selección Artificial , Análisis de Secuencia de ADN , Siberia , Triglicéridos/metabolismo , Lobos/genética
4.
Sci Total Environ ; 726: 137908, 2020 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-32481217

RESUMEN

One century after their introduction to Europe, eastern mosquitofish (Gambusia holbrooki) represent a natural experiment to determine the relative contributions of adaptive plasticity and rapid evolutionary change in creating large-scale geographic variation in phenotypes. We evaluated the population-genetic structure and invasion history based on allele length polymorphisms of 15 nuclear microsatellites, which we quantified for N = 660 individuals from 23 populations sampled in 2013 across the invasive range of G. holbrooki in Europe. We analysed body-shape and life-history variation in N = 1331 individuals from 36 populations, sampled in 2013 and 2017, and tested heritability of phenotypic differences in a subset of four populations using a common-garden experiment. The genetic structure of wild-caught individuals suggested a single introduction for all European mosquitofish, which were genetically impoverished compared to their native counterparts. We found some convergent patterns of phenotypic divergence across native and invasive climatic gradients (e.g., increased body size in colder/more northern populations); however, several phenotypic responses were not consistent between sampling years, pointing towards plastic phenotypes. Our analysis of common-garden reared individuals uncovered moderate heritability estimates only for two measures of male body size (intraclass correlation coefficient, ICC = 0.628 and 0.556) and offspring fat content (ICC = 0.734), while suggesting high levels of plasticity in most other phenotypic traits (ICC ≤ 0.407). Our results highlight the importance of phenotypic plasticity in invasive species during range expansions and demonstrate that strong selective pressures-in this case towards increased body size in colder environments-simultaneously promote rapid evolutionary divergence.


Asunto(s)
Ciprinodontiformes , Adaptación Fisiológica , Animales , Europa (Continente) , Especies Introducidas , Masculino , Fenotipo
5.
PLoS Biol ; 18(6): e3000744, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32559190

RESUMEN

Dopamine guides behavior and learning through pleasure, according to classic understanding. Dopaminergic neurons are traditionally thought to signal positive or negative prediction errors (PEs) when reward expectations are, respectively, exceeded or not matched. These signed PEs are quite different from the unsigned PEs, which report surprise during sensory processing. But mounting theoretical accounts from the predictive processing framework postulate that dopamine, as a neuromodulator, could potentially regulate the postsynaptic gain of sensory neurons, thereby scaling unsigned PEs according to their expected precision or confidence. Despite ample modeling work, the physiological effects of dopamine on the processing of surprising sensory information are yet to be addressed experimentally. In this study, we tested how dopamine modulates midbrain processing of unexpected tones. We recorded extracellular responses from the rat inferior colliculus to oddball and cascade sequences, before, during, and after the microiontophoretic application of dopamine or eticlopride (a D2-like receptor antagonist). Results demonstrate that dopamine reduces the net neuronal responsiveness exclusively to unexpected sensory input without significantly altering the processing of expected input. We conclude that dopaminergic projections from the thalamic subparafascicular nucleus to the inferior colliculus could encode the expected precision of unsigned PEs, attenuating via D2-like receptors the postsynaptic gain of sensory inputs forwarded by the auditory midbrain neurons. This direct dopaminergic modulation of sensory PE signaling has profound implications for both the predictive coding framework and the understanding of dopamine function.


Asunto(s)
Corteza Cerebral/fisiología , Dopamina/farmacología , Sonido , Estimulación Acústica , Adaptación Fisiológica , Animales , Corteza Cerebral/efectos de los fármacos , Femenino , Ratas Long-Evans , Salicilamidas/farmacología , Tálamo/fisiología
6.
Braz J Med Biol Res ; 53(7): e8763, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32520205

RESUMEN

Upper limb performance is affected by diabetes mellitus (DM). Neuromuscular junction (NMJ) is a key structure to understand the relationship between performance and morphology in DM. The aim of the study was to analyze NMJ plasticity due to DM in an animal model and its relationship with the function of forelimbs in rats. Twelve Wistar rats were divided into control (C) and DM groups. Animals were trained to perform a grasping task, following procedures of habituation, shaping, and reaching task. DM was induced using streptozotocin. Forelimb neuromuscular performance for dexterity was evaluated one day before DM induction and five weeks following induction. After that, biceps, triceps, and finger flexors and extensors were removed. Connective tissue and muscle fiber cross-sectional area (CSA) were measured. NMJ was assessed by its morphometric characteristics (area, perimeter, and maximum diameter), using ImageJ software. Motor performance analyses were made using single pellet retrieval task performance test. Student's t-test was used for comparisons between groups. A significant decrease in all NMJ morphometric parameters was observed in the DM group compared with the C group. Results showed that DM generated NMJ retraction in muscles involved in a reaching task. These alterations are related to signs of muscular atrophy and to poor reaching task performance. In conclusion, induced DM caused NMJ retraction and muscular atrophy in muscles involved in reaching task performance. Induced DM caused significantly lower motor performance, especially in the final moments of evaluation, when DM compromised the tropism of the muscular tissue.


Asunto(s)
Adaptación Fisiológica/fisiología , Diabetes Mellitus Experimental/patología , Unión Neuromuscular/patología , Análisis y Desempeño de Tareas , Animales , Diabetes Mellitus Experimental/fisiopatología , Masculino , Ratones , Unión Neuromuscular/fisiopatología , Ratas , Ratas Wistar
7.
Science ; 368(6495): 1127-1131, 2020 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-32499442

RESUMEN

In microorganisms, evolutionarily conserved mechanisms facilitate adaptation to harsh conditions through stress-induced mutagenesis (SIM). Analogous processes may underpin progression and therapeutic failure in human cancer. We describe SIM in multiple in vitro and in vivo models of human cancers under nongenotoxic drug selection, paradoxically enhancing adaptation at a competing intrinsic fitness cost. A genome-wide approach identified the mechanistic target of rapamycin (MTOR) as a stress-sensing rheostat mediating SIM across multiple cancer types and conditions. These observations are consistent with a two-phase model for drug resistance, in which an initially rapid expansion of genetic diversity is counterbalanced by an intrinsic fitness penalty, subsequently normalizing to complete adaptation under the new conditions. This model suggests synthetic lethal strategies to minimize resistance to anticancer therapy.


Asunto(s)
Adaptación Fisiológica/genética , Antineoplásicos/farmacología , Resistencia a Antineoplásicos/genética , Mutagénesis , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Serina-Treonina Quinasas TOR/metabolismo , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Reparación del ADN/genética , Aptitud Genética , Estudio de Asociación del Genoma Completo , Humanos , Selección Genética , Transducción de Señal , Serina-Treonina Quinasas TOR/genética
8.
Ecotoxicol Environ Saf ; 201: 110855, 2020 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-32540620

RESUMEN

Total dissolved gas (TDG) supersaturation generated by discharged flood water may cause the death of fish downstream of dams and severely threaten their survival during the flood season. No study has performed to investigate the effects of TDG on fish dwelling in shallows in China. Furthermore, varied TDG levels are caused by the varied flow of flood water during the spill season. Fish may alternatingly experience intermittent TDG exposure from equilibrated water and TDG-supersaturated water. However, little research on the effects of intermittent TDG exposure on fish has been conducted. To evaluate the tolerance of fish to continuous acute TDG exposure, juvenile yellow catfish living in the shallows were exposed to TDG-supersaturated water at 125%, 130%, 135% and 140% TDG for 96 h. The results showed that the juvenile yellow catfish exhibited obvious gas bubble disease (GBD) and abnormal behaviours (e.g., exophthalmos and bubbles on fins). The survival probability declined with the arising TDG levels. The median survival time (ST50) of yellow catfish was 8.57, 18.1, 33.86 and 58.84 h at above TDG levels, respectively. To further investigate the effects of intermittent TDG exposure on juvenile yellow catfish, the fish were subjected to varied TDG levels (125%, 130%, 135% and 140%) for a specific duration (3 h and 6 h) and then underwent a period of recovery (3, 6 and 9 h) in equilibrated water. The results showed that an increase in recovery time (or decreasing exposure time) can prolong the survival time of yellow catfish and improve their survival probability at the same exposure time (or same recovery time). Compared with that under continuous acute exposure, the ST50 of juvenile yellow catfish increased significantly with intermittent exposure. Intermittent exposure can enhance the tolerance of juvenile yellow catfish to TDG. The application of the results may contribute to the protection of aquatic organisms and the formulation of the scheme of reservoir operation in the Yangtze River.


Asunto(s)
Adaptación Fisiológica/efectos de los fármacos , Bagres/fisiología , Gases/toxicidad , Ríos/química , Contaminantes del Agua/toxicidad , Animales , Conducta Animal/efectos de los fármacos , China , Gases/análisis , Probabilidad , Análisis de Supervivencia , Movimientos del Agua , Contaminantes del Agua/análisis , Calidad del Agua
9.
Gene ; 756: 144914, 2020 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-32574759

RESUMEN

The life history of the Chinese mitten crab (Eriocheir japonica sinensis) includes two migrations: a feeding migration and a reproductive migration. Ambient salinity is one of the most critical factors during migration. In this study, the salinity adaptation mechanism of Chinese mitten crabs was simulated using continuous salinity changes. The expression of six key genes [Na+/K+-ATPase α subunit (NAK-α), V-type H+-ATPase subunit A (VHA-A), Zinc transporter (ZnT), Cl- channel protein 2 (CLCN2), ubiquitin/ribosomal S27 fusionprotein (S27), and glutathione S-transferase (GST)] and the activities of three enzymes [Na+/K+-ATPase (NAK), V-type H+-ATPase (VHA), and glutathione S-transferase (GST)] were evaluated in ten groups exposed to a range of salinity changes during mariculture based on the transcriptome data obtained from short term salinity-induced crabs (ES) compared to control group in freshwater crabs (EF). The results revealed that different genes exhibited different roles in physiological regulation. In total, 3,599 unigenes were significantly and differentially expressed in a comparison between the EF and ES treatments. A novel modulation of gene expression and the corresponding enzyme activity of NAK and VHA exhibited similar patterns. As genes related to osmoregulation, NAK and VHA showed similar patterns of both gene expression and enzyme activity in mariculture. During the gradual change in salinity from 0‰ to 25‰ and back to 0‰, the gene expression and enzyme activities of NAK and VHA initially increased (0‰ â†’ 10‰), weakened (10‰ â†’ 20‰) and then increased again (20‰ â†’ 25‰ â†’ 0‰). S27 could serve as a reference gene in the expression analysis of Chinese mitten crabs under salinity stress. ZnT and CLCN2 were involved in osmoregulation as functional proteins. Our findings provide insights into the regulation mechanisms employed during the migration of the Chinese mitten crab.


Asunto(s)
Braquiuros/genética , Braquiuros/fisiología , Osmorregulación , Adaptación Fisiológica , Migración Animal , Animales , Proteínas de Artrópodos/genética , Proteínas de Transporte de Catión/genética , Agua Dulce , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Branquias/fisiología , Masculino , Salinidad , Análisis de Secuencia de ARN
10.
PLoS Negl Trop Dis ; 14(6): e0007759, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32555641

RESUMEN

Naegleria fowleri is a single-cell organism living in warm freshwater that can become a deadly human pathogen known as a brain-eating amoeba. The condition caused by N. fowleri, primary amoebic meningoencephalitis, is usually a fatal infection of the brain with rapid and severe onset. Iron is a common element on earth and a crucial cofactor for all living organisms. However, its bioavailable form can be scarce in certain niches, where it becomes a factor that limits growth. To obtain iron, many pathogens use different machineries to exploit an iron-withholding strategy that has evolved in mammals and is important to host-parasite interactions. The present study demonstrates the importance of iron in the biology of N. fowleri and explores the plausibility of exploiting iron as a potential target for therapeutic intervention. We used different biochemical and analytical methods to explore the effect of decreased iron availability on the cellular processes of the amoeba. We show that, under iron starvation, nonessential, iron-dependent, mostly cytosolic pathways in N. fowleri are downregulated, while the metal is utilized in the mitochondria to maintain vital respiratory processes. Surprisingly, N. fowleri fails to respond to acute shortages of iron by inducing the reductive iron uptake system that seems to be the main iron-obtaining strategy of the parasite. Our findings suggest that iron restriction may be used to slow the progression of infection, which may make the difference between life and death for patients.


Asunto(s)
Adaptación Fisiológica , Regulación de la Expresión Génica , Hierro/metabolismo , Naegleria fowleri/genética , Naegleria fowleri/metabolismo , Respiración de la Célula , Mitocondrias/metabolismo , Oligoelementos/metabolismo
11.
Proc Biol Sci ; 287(1928): 20200608, 2020 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-32486974

RESUMEN

Body size is a key functional trait that is predicted to decline under warming. Warming is known to cause size declines via phenotypic plasticity, but evolutionary responses of body size to warming are poorly understood. To test for warming-induced evolutionary responses of body size and growth rates, we used populations of mosquitofish (Gambusia affinis) recently established (less than 100 years) from a common source across a strong thermal gradient (19-33°C) created by geothermal springs. Each spring is remarkably stable in temperature and is virtually closed to gene flow from other thermal environments. Field surveys show that with increasing site temperature, body size distributions become smaller and the reproductive advantage of larger body size decreases. After common rearing to reveal recently evolved trait differences, warmer-source populations expressed slowed juvenile growth rates and increased reproductive effort at small sizes. These results are consistent with an adaptive basis of the plastic temperature-size rule, and they suggest that temperature itself can drive the evolution of countergradient variation in growth rates. The rapid evolution of reduced juvenile growth rates and greater reproduction at a small size should contribute to substantial body downsizing in populations, with implications for population dynamics and for ecosystems in a warming world.


Asunto(s)
Evolución Biológica , Tamaño Corporal , Calentamiento Global , Adaptación Fisiológica , Animales , Ecosistema , Reproducción , Temperatura
12.
Nature ; 581(7806): 67-70, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32376955

RESUMEN

In recent decades, intensive research on non-avian dinosaurs has strongly suggested that these animals were restricted to terrestrial environments1. Historical proposals that some groups, such as sauropods and hadrosaurs, lived in aquatic environments2,3 were abandoned decades ago4-6. It has recently been argued that at least some of the spinosaurids-an unusual group of large-bodied theropods of the Cretaceous era-were semi-aquatic7,8, but this idea has been challenged on anatomical, biomechanical and taphonomic grounds, and remains controversial9-11. Here we present unambiguous evidence for an aquatic propulsive structure in a dinosaur, the giant theropod Spinosaurus aegyptiacus7,12. This dinosaur has a tail with an unexpected and unique shape that consists of extremely tall neural spines and elongate chevrons, which forms a large, flexible fin-like organ capable of extensive lateral excursion. Using a robotic flapping apparatus to measure undulatory forces in physical models of different tail shapes, we show that the tail shape of Spinosaurus produces greater thrust and efficiency in water than the tail shapes of terrestrial dinosaurs and that these measures of performance are more comparable to those of extant aquatic vertebrates that use vertically expanded tails to generate forward propulsion while swimming. These results are consistent with the suite of adaptations for an aquatic lifestyle and piscivorous diet that have previously been documented for Spinosaurus7,13,14. Although developed to a lesser degree, aquatic adaptations are also found in other members of the spinosaurid clade15,16, which had a near-global distribution and a stratigraphic range of more than 50 million years14, pointing to a substantial invasion of aquatic environments by dinosaurs.


Asunto(s)
Dinosaurios/anatomía & histología , Dinosaurios/fisiología , Natación , Cola (estructura animal)/anatomía & histología , Cola (estructura animal)/fisiología , Agua , Adaptación Fisiológica , Animales , Organismos Acuáticos/clasificación , Organismos Acuáticos/fisiología , Dieta/veterinaria , Dinosaurios/clasificación , Ecosistema , Peces , Robótica , Columna Vertebral/anatomía & histología
13.
Science ; 368(6491): 604-607, 2020 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-32381716

RESUMEN

Molecules from symbiotic microorganisms pervasively infiltrate almost every organ system of a mammalian host, marking the initiation of microbial-host mutualism in utero, long before the newborn acquires its own microbiota. Starting from in utero development, when maternal microbial molecules can penetrate the placental barrier, we follow the different phases of adaptation through the life events of birth, lactation, and weaning, as the young mammal adapts to the microbes that colonize its body surfaces. The vulnerability of early-life mammals is mitigated by maternal detoxification and excretion mechanisms, the protective effects of maternal milk, and modulation of neonatal receptor systems. Host adaptations to microbial exposure during specific developmental windows are critical to ensure organ function for development, growth, and immunity.


Asunto(s)
Bacterias/metabolismo , Feto/inmunología , Feto/microbiología , Interacciones Microbiota-Huesped/inmunología , Intercambio Materno-Fetal/inmunología , Microbiota , Adaptación Fisiológica/inmunología , Animales , Dieta , Femenino , Humanos , Inmunidad Innata , Lactancia/inmunología , Exposición Materna , Fenómenos Fisiologicos Nutricionales Maternos , Ratones , Placentación , Embarazo , Xenobióticos/toxicidad
14.
Nat Commun ; 11(1): 2214, 2020 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-32371941

RESUMEN

MSH1 is a plant-specific protein. RNAi suppression of MSH1 results in phenotype variability for developmental and stress response pathways. Segregation of the RNAi transgene produces non-genetic msh1 'memory' with multi-generational inheritance. First-generation memory versus non-memory comparison, and six-generation inheritance studies, identifies gene-associated, heritable methylation repatterning. Genome-wide methylome analysis integrated with RNAseq and network-based enrichment studies identifies altered circadian clock networks, and phytohormone and stress response pathways that intersect with circadian control. A total of 373 differentially methylated loci comprising these networks are sufficient to discriminate memory from nonmemory full sibs. Methylation inhibitor 5-azacytidine diminishes the differences between memory and wild type for growth, gene expression and methylation patterning. The msh1 reprogramming is dependent on functional HISTONE DEACETYLASE 6 and methyltransferase MET1, and transition to memory requires the RNA-directed DNA methylation pathway. This system of phenotypic plasticity may serve as a potent model for defining accelerated plant adaptation during environmental change.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Metilación de ADN , Proteína MutS de Unión a los Apareamientos Incorrectos del ADN/genética , Carácter Cuantitativo Heredable , Interferencia de ARN , Transgenes/genética , Adaptación Fisiológica/genética , ADN (Citosina-5-)-Metiltransferasas/genética , Epigénesis Genética , Perfilación de la Expresión Génica/métodos , Ontología de Genes , Redes Reguladoras de Genes , Estudio de Asociación del Genoma Completo/métodos , Histona Desacetilasa 6/genética , Patrón de Herencia/genética , Plantas Modificadas Genéticamente , Transducción de Señal/genética
15.
PLoS One ; 15(5): e0226453, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32379825

RESUMEN

Membrane transporters carry key metabolites across the cell membrane and, from a resource standpoint, are hypothesized to be produced when necessary. The expression of membrane transporters in metabolic pathways is often upregulated by the transporter substrate. In E. coli, such systems include for example the lacY, araFGH, and xylFGH genes, which encode for lactose, arabinose, and xylose transporters, respectively. As a case study of a minimal system, we build a generalizable physical model of the xapABR genetic circuit, which features a regulatory feedback loop via membrane transport (positive feedback) and enzymatic degradation (negative feedback) of an inducer. Dynamical systems analysis and stochastic simulations show that the membrane transport makes the model system bistable in certain parameter regimes. Thus, it serves as a genetic "on-off" switch, enabling the cell to only produce a set of metabolic enzymes when the corresponding metabolite is present in large amounts. We find that the negative feedback from the degradation enzyme does not significantly disturb the positive feedback from the membrane transporter. We investigate hysteresis in the switching and discuss the role of cooperativity and multiple binding sites in the model circuit. Fundamentally, this work explores how a stable genetic switch for a set of enzymes is obtained from transcriptional auto-activation of a membrane transporter through its substrate.


Asunto(s)
Adaptación Fisiológica/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Redes Reguladoras de Genes , Genes de Cambio , Modelos Biológicos , Sitios de Unión , Transporte Biológico/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Retroalimentación Fisiológica , Regulación Bacteriana de la Expresión Génica , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Pentosiltransferasa/genética , Pentosiltransferasa/metabolismo , Regiones Promotoras Genéticas , ARN Mensajero/metabolismo , Ribonucleósidos/metabolismo , Procesos Estocásticos , Transactivadores/genética , Transactivadores/metabolismo , Transcripción Genética
16.
Phytochemistry ; 176: 112403, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32422392

RESUMEN

Prostanthera lasianthos (Lamiaceae) is commonly referred to as the 'Victorian Christmas Bush', a name that derives from the floral display it gives in the Christmas period. However, botanists recognise P. lasianthos as a heterogeneous species aggregate that includes several putative new species that are confined to disjunct locations. Recently one taxon was revised to P. eungella B.J.Conn & K.M.Proft. In the current study the chemistry of essential oils was determined for 25 specimens, representative of 8 taxa (including P. eungella). Chemical relationships were investigated using two types of multivariate analysis and several distinct chemical profiles were identified. One taxon (P. sp. Wollomombi Gorge) was sampled nine times from three different locations during the year to determine the effects of seasonal variation and subjectively-assessed soil moisture content. It was demonstrated that the chemistry of this taxon is strongly influenced by soil moisture independently of growth stage, but possibly influenced by periods of dry or wet weather. Two distinct chemotypes and one intermediate type were identified. These chemotypes differed by mediated expression of linalool and hence linalyl acetate. These metabolites were also present in specimens of P. sp. Bald Mountain, but as minor components. This latter taxon could be reliably distinguished by higher relative abundance of butanoic acid, 1-methylbutyl ester. As judged by a smaller sampling size for the other taxa, evidence that this pattern of mediated expression between terpene species was found. However, the identity of terpenes that demonstrated this mediated expression were different for each taxon; for example, volatiles from P. eungella demonstrated mediation between α-pinene and caryophyllene. Nevertheless, it is possible that chemical expression of all taxa in the heterogeneous species aggregate is strongly mediated by the moisture or nutrient content of soils. Thus, the dataset produced during this study can be used as a reference against other chemical data to investigate taxonomic placement in members of this group.


Asunto(s)
Lamiaceae , Aceites Volátiles , Adaptación Fisiológica , Australia , Terpenos
17.
PLoS One ; 15(5): e0233012, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32469878

RESUMEN

Leukocyte migration is controlled by a membrane-based chemosensory pathway on the leading edge pseudopod that guides cell movement up attractant gradients during the innate immune and inflammatory responses. This study employed single cell and population imaging to investigate drug-induced perturbations of leading edge pseudopod morphology in cultured, polarized RAW macrophages. The drugs tested included representative therapeutics (acetylsalicylic acid, diclofenac, ibuprofen, acetaminophen) as well as control drugs (PDGF, Gö6976, wortmannin). Notably, slow addition of any of the four therapeutics to cultured macrophages, mimicking the slowly increasing plasma concentration reported for standard oral dosage in patients, yielded no detectable change in pseudopod morphology. This finding is consistent with the well established clinical safety of these drugs. However, rapid drug addition to cultured macrophages revealed four distinct classes of effects on the leading edge pseudopod: (i) non-perturbing drug exposures yielded no detectable change in pseudopod morphology (acetylsalicylic acid, diclofenac); (ii) adaptive exposures yielded temporary collapse of the extended pseudopod and its signature PI(3,4,5)P3 lipid signal followed by slow recovery of extended pseudopod morphology (ibuprofen, acetaminophen); (iii) disruptive exposures yielded long-term pseudopod collapse (Gö6976, wortmannin); and (iv) activating exposures yielded pseudopod expansion (PDGF). The novel observation of adaptive exposures leads us to hypothesize that rapid addition of an adaptive drug overwhelms an intrinsic or extrinsic adaptation system yielding temporary collapse followed by adaptive recovery, while slow addition enables gradual adaptation to counteract the drug perturbation in real time. Overall, the results illustrate an approach that may help identify therapeutic drugs that temporarily inhibit the leading edge pseudopod during extreme inflammation events, and toxic drugs that yield long term inhibition of the pseudopod with negative consequences for innate immunity. Future studies are needed to elucidate the mechanisms of drug-induced pseudopod collapse, as well as the mechanisms of adaptation and recovery following some inhibitory drug exposures.


Asunto(s)
Macrófagos/efectos de los fármacos , Seudópodos/efectos de los fármacos , Acetaminofén/farmacología , Adaptación Fisiológica , Animales , Aspirina/farmacología , Movimiento Celular/efectos de los fármacos , Movimiento Celular/fisiología , Polaridad Celular/efectos de los fármacos , Polaridad Celular/fisiología , Diclofenaco/farmacología , Humanos , Ibuprofeno/farmacología , Inmunidad Innata/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/fisiología , Ratones , Seudópodos/fisiología , Seudópodos/ultraestructura , Células RAW 264.7 , Imagen de Lapso de Tiempo
18.
PLoS One ; 15(5): e0231817, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32374734

RESUMEN

Significant population declines in Acropora cervicornis and A. palmata began in the 1970s and now exceed over 90%. The losses were caused by a combination of coral disease and bleaching, with possible contributions from other stressors, including pollution and predation. Reproduction in the wild by fragment regeneration and sexual recruitment is inadequate to offset population declines. Starting in 2007, the Coral Restoration Foundation™ evaluated the feasibility of outplanting A. cervicornis colonies to reefs in the Florida Keys to restore populations at sites where the species was previously abundant. Reported here are the results of 20 coral outplanting projects with each project defined as a cohort of colonies outplanted at the same time and location. Photogrammetric analysis and in situ monitoring (2007 to 2015) measured survivorship, growth, and condition of 2419 colonies. Survivorship was initially high but generally decreased after two years. Survivorship among projects based on colony counts ranged from 4% to 89% for seven cohorts monitored at least five years. Weibull survival models were used to estimate survivorship beyond the duration of the projects and ranged from approximately 0% to over 35% after five years and 0% to 10% after seven years. Growth rate averaged 10 cm/year during the first two years then plateaued in subsequent years. After four years, approximately one-third of surviving colonies were ≥ 50 cm in maximum diameter. Projects used three to sixteen different genotypes and significant differences did not occur in survivorship, condition, or growth. Restoration times for three reefs were calculated based on NOAA Recovery Plan (NRP) metrics (colony abundance and size) and the findings from projects reported here. Results support NRP conclusions that reducing stressors is required before significant population growth and recovery will occur. Until then, outplanting protects against local extinction and helps to maintain genetic diversity in the wild.


Asunto(s)
Adaptación Fisiológica/fisiología , Antozoos/crecimiento & desarrollo , Conservación de los Recursos Naturales/métodos , Arrecifes de Coral , Restauración y Remediación Ambiental/métodos , Animales , Antozoos/citología , Supervivencia Celular , Especies en Peligro de Extinción , Extinción Biológica , Florida , Crecimiento Demográfico , Evaluación de Programas y Proyectos de Salud
19.
Proc Biol Sci ; 287(1927): 20200559, 2020 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-32396796

RESUMEN

Coexistence results from a complex suite of past and contemporary processes including biogeographic history, adaptation, ecological interactions and reproductive dynamics. Here we explore drivers of local micro-parapatry in which two closely related and reproductively isolated Streptanthus species (jewelflower, Brassicaceae) inhabit continuous or adjacent habitat patches and occur within seed dispersal range, yet rarely overlap in fine-scale distribution. We find some evidence for abiotic niche partitioning and local adaptation, however differential survival across habitats cannot fully explain the scarcity of coexistence. Competition may also reduce the fitness of individuals migrating into occupied habitats, yet its effects are insufficient to drive competitive exclusion. Experimental migrants suffered reduced seed production and seed viability at sites occupied by heterospecifics, and we infer that heterospecific pollen transfer by shared pollinators contributes to wasted gametes when the two congeners come into contact. A minority disadvantage may reduce effective colonization of patches already occupied by heterospecifics, even when habitat patches are environmentally suitable. Differential adaptation and resource competition have often been evoked as primary drivers of habitat segregation in plants, yet negative reproductive interactions-including reproductive interference and decreased fecundity among low-frequency migrants-may also contribute to non-overlapping distributions of related species along local tension zones.


Asunto(s)
Adaptación Fisiológica/fisiología , Brassicaceae/fisiología , Ecosistema , Polen , Polinización , Reproducción , Dispersión de Semillas , Simpatría
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