Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 170
Filtrar
1.
J Toxicol Environ Health B Crit Rev ; 27(4): 153-187, 2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-38517360

RESUMEN

The widespread production and use of plastics have resulted in accumulation of plastic debris in the environment, gradually breaking down into smaller particles over time. Nano-plastics (NPs) and microplastics (MPs), defined as particles smaller than 100 nanometers and 5 millimeters, respectively, raise concerns due to their ability to enter the human body through various pathways including ingestion, inhalation, and skin contact. Various investigators demonstrated that these particles may produce physical and chemical damage to human cells, tissues, and organs, disrupting cellular processes, triggering inflammation and oxidative stress, and impacting hormone and neurotransmitter balance. In addition, micro- and nano-plastics (MNPLs) may carry toxic chemicals and pathogens, exacerbating adverse effects on human health. The magnitude and nature of these effects are not yet fully understood, requiring further research for a comprehensive risk assessment. Nevertheless, evidence available suggests that accumulation of these particles in the environment and potential human uptake are causes for concern. Urgent measures to reduce plastic pollution and limit human exposure to MNPLs are necessary to safeguard human health and the environment. In this review, current knowledge regarding the influence of MNPLs on human health is summarized, including toxicity mechanisms, exposure pathways, and health outcomes across multiple organs. The critical need for additional research is also emphasized to comprehensively assess potential risks posed by degradation of MNPLs on human health and inform strategies for addressing this emerging environmental health challenge. Finally, new research directions are proposed including evaluation of gene regulation associated with MNPLs exposure.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Contaminantes Químicos del Agua , Humanos , Microplásticos/toxicidad , Plásticos/toxicidad , Transporte Biológico , Modelos Teóricos
2.
J Invertebr Pathol ; 203: 108057, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38176675

RESUMEN

Nitric oxide (NO) is a simple molecule involved in many biological processes and functions in the cardiovascular, neural, and immune systems. In recent years, NO has also been recognized as a crucial messenger in communication between the nervous and immune systems. Together with NO, catecholamines are the main group of neurotransmitters involved in cross-talk between the nervous and immune systems. Catecholamines such as noradrenaline, can act on immune cells through adrenoreceptors (ARs) present on the cell surface, and NO can cross the cell membrane and interact with secondary messengers, modulating catecholamine production. Here, we analyzed the mutual modulation by noradrenaline and NO in Phallusia nigra immune cells for specific subtypes of ARs. We also investigated the involvement of protein kinases A and C as secondary messengers to these specific subtypes of ARs in the adrenergic signaling pathway that culminates in NO modulation, and the phylogenetic distribution of ARs in deuterostome genomes. This analysis provided evidence for single-copy orthologs of α1, α2 and ß-AR in ascidian genomes, suggesting that NO and NA act on a less diverse set of ARs in urochordates. Pharmacological assays showed that high levels of NO can induce ascidian immune cells to produce catecholamines. We also observed that protein kinases A and C are the secondary messengers involved in downstream modulation of NO production through an ancestral ß-AR. Taken together, these results provide new information on NO as a modulator of immune cells, and reveal the molecules involved in the signaling pathway of ARs. The results also indicate that ARs may participate in NO modulation. Finally, our results suggest that the common ancestor of urochordates possessed a less complex system of ARs required for immune action and diverse pharmacological responses, since the α-ARs are phylogenetically more related to D1-receptors than are the ß-ARs.


Asunto(s)
Óxido Nítrico , Urocordados , Animales , Filogenia , Catecolaminas/metabolismo , Norepinefrina , Proteínas Quinasas
3.
Arch Insect Biochem Physiol ; 114(1): e22029, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37278151

RESUMEN

Inorganic polyphosphate (polyP) is a biopolymer composed of phosphoanhydride-linked orthophosphate molecules. PolyP is engaged in a variety of cellular functions, including mitochondrial metabolism. Here, we examined the effects of polyP on electron transport chain enzymes and F1 Fo ATP synthase in tick embryos during embryonic development. The study found that polyPs containing medium and long chains (polyP15 and polyP65 ) enhanced the activity of complex I, complex II, complex III, and F1 Fo ATP synthase, while short polyP chains (polyP3 ) had no effect. The study also examined the activity of exopolyphosphatases (PPX) in various energy-demand situations. PPX activity was stimulated when ADP concentrations are high, characterizing a low-energy context. When complexes I-III and F1 Fo ATP synthase inhibitors were added in energized mitochondria, PPX activity decreased, whereas the mitochondrial uncoupler FCCP had no impact on PPX activity. Additionally, the study investigated the effect of polyP on mitochondrial swelling, finding that polyP causes mitochondrial swelling by increasing calcium effects on the mitochondrial permeability transition pore. The findings presented here to increase our understanding of the function of polyP in mitochondrial metabolism and its relationship to mitochondrial permeability transition pore opening in an arthropod model.


Asunto(s)
Poro de Transición de la Permeabilidad Mitocondrial , Garrapatas , Animales , Poro de Transición de la Permeabilidad Mitocondrial/metabolismo , Poro de Transición de la Permeabilidad Mitocondrial/farmacología , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Proteínas de Transporte de Membrana Mitocondrial/farmacología , Mitocondrias/metabolismo , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/farmacología , Polifosfatos/farmacología , Polifosfatos/metabolismo , Calcio/metabolismo
4.
An Acad Bras Cienc ; 94(suppl 3): e20211536, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36477240

RESUMEN

This study investigated the renal function of soccer players after an entire game-season. Thirty-five athletes recruited to play for the Macae Futebol Clube were invited for this study, of which 18 athletes completed the entire game season. Blood and 24-hour urine were collected at the beginning (Pre-Season) and the end of the game season (Post-Season). Kidney functions were assessed by calculating the urinary excretion, clearance, and fractional excretion of the selected solutes. Plasma creatinine, sodium, total protein, and osmolality were lower in the Post-Season . In contrast, plasma urea was higher in the Post-Season period. Urinary excretion of urea was reduced while albumin excretion was higher in comparison to Pre-Season. The clearances of creatinine, total proteins, and albumin were higher in the Post-Season period. In accordance, the fractional excretion of albumin increased. On the other hand, the clearance and fractional excretion of urea was lower in the Post-Season period. These results show that soccer-associated exercise throughout the entire game-season induces kidney functions adaptations that may prevent dehydration in these athletes through increased urea reabsorption to conserve water. In addition, this data corroborates to increased glomerular permeability to plasma proteins, such as albumin, that soccer players may experience.


Asunto(s)
Ejercicio Físico , Urea , Humanos , Riñón
5.
An Acad Bras Cienc ; 94(suppl 3): e20211361, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36417609

RESUMEN

Since the first reported case of COVID-19 in Brazil, the public and private educational system started to close. Up to November 2020, scientific discussions about the return of schooling activities have been rarely performed by the national scientific community and police-makers. The great delay of school returning in Brazil contrasts with successful international strategies of school reopening worldwide and seems counterintuitive with the reopening of non-essential activities. Here, important issues to be considered before and during school reopening are reviewed and discussed. COVID-19 testing is essential to avoid disease spreading, but high cost of individual RT-qPCRs impairs an extensive testing strategy for school returning. To reduce costs and increase the speed of diagnosis, we tested the efficiency of a pooled-sample PCR strategy in a cohort of the educational staff in the city of Macaé/RJ, finding five asymptomatic individuals (0,66%) among the 754 people tested. Thus, a polled-sample PCR testing strategy of the educational staff might prevent infection spreading in schools at a reasonable cost. We discuss how our test strategy could be coupled with internationally recognized safety rules to allow for a safe school return and how countries from different world regions are dealing with educational activities during COVID-19 pandemic.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Pandemias , Prueba de COVID-19 , Brasil/epidemiología , Instituciones Académicas
6.
Int J Mol Sci ; 23(19)2022 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-36232806

RESUMEN

The SARS-CoV-2 virus infection led to millions of deaths during the COVID-19 pandemic. Hundreds of workers from several other Brazilian cities, as well as from other countries, arrive daily in Macaé to work in the oil supply chain, making this city a putative hotspot for the introduction of new viral lineages. In this study, we performed a genomic survey of SARS-CoV-2 samples from Macaé during the first outbreak of COVID-19, combined with clinical data and a molecular integrative analysis. First, phylogenomic analyses showed a high occurrence of viral introduction events and the establishment of local transmissions in Macaé, including the ingression and spread of the B.1.1.28 lineage in the municipality from June to August 2020. Second, SARS-CoV-2 mutations were identified in patients with distinct levels of COVID-19 severity. Third, molecular interactions of the mutated spike protein from three B.1.1.33 local samples and human ACE2 showed higher interactions than that of the wild-type spike protein from the ancestral virus. Altogether, these results elucidate the SARS-CoV-2 genomic profile in a strategic Brazilian city and further explore the functional aspects of SARS-CoV-2 with a characterization of emerging viral mutations associated with clinical data and the potential targets for drug development against SARS-CoV-2.


Asunto(s)
COVID-19 , SARS-CoV-2 , Enzima Convertidora de Angiotensina 2 , Brasil/epidemiología , COVID-19/epidemiología , Genómica , Humanos , Mutación , Pandemias , Filogenia , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genética
7.
Rev Med Chil ; 150(2): 241-247, 2022 Feb.
Artículo en Español | MEDLINE | ID: mdl-36156651

RESUMEN

The transition to and through college can affect the mental health of college students. The situation in medical students is particularly worrisome, considering that they have high rates of psychopathology. These mental health problems can be associated with worse academic and professional outcomes and worse patient care. In this scenario, it is relevant to look at how this problem can be addressed considering variables of both mental health and educational systems in medicine. Therefore, initiatives to promote well-being during the career are proposed. The importance of well-being at an institutional level should be defined. Also, the foundations of learning neurosciences from the point of view of well-being should be incorporated. Considering that well-being goes beyond the absence of discomfort, the role of educational environment both in learning and in mental health should be recognized. Proven effective interventions should be incorporated. It must be considered that not every initiative linked to well-being is necessarily positive and that discomfort to a certain extent can be exploited educatively as well. The well-being of medical students is a complex, dynamic and multidimensional issue. These principles are orientations for different actors of the educational process, to define how they will approach this problem in their contexts.


Asunto(s)
Educación Médica , Neurociencias , Estudiantes de Medicina , Humanos , Aprendizaje , Neurociencias/educación
8.
Fish Shellfish Immunol ; 109: 41-50, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33285170

RESUMEN

Dopamine (DA) is an important molecule that plays a role in the nervous and immune systems. DA is produced by a wide variety of animals and it is considered one of the oldest neurotransmitters. However, its specific function in immune cells has not been completely revealed. In a group of chordate animals, the ascidians, DA is reported to be produced by cells in the central nervous system (CNS); however, no dopaminergic receptor in their genomes has been described until now. Because this is an integrating characteristic of the ascidian dopamine system, here it was investigated the pharmacology, function, and phylogeny of DA and dopaminergic receptors (DRs) in the modulation of nitric oxide (NO) in the Phallusia nigra immune cells. The data disclosed, for the first time, that DA modulates NO production by immune cells. Its modulation probably occurs though adrenergic receptors, which display a special characteristic, in that they are capable of binding to noradrenaline (NA) and DA. A pharmacological analysis revealed that receptors present on the ascidian immune cells showed a high affinity to butaclamol, a non-selective D2-class receptor, increasing NO production. In addition, calcium intracellular mobilization was observed when DA was added to immune cells. In conclusion, the data revealed novel insights about the presence of catecholaminergic receptors (CRs) on the P. nigra immune cells, indicating that ascidian CRs have special pharmacological characteristics that are worth highlighting from an evolutionary point of view.


Asunto(s)
Dopamina/farmacología , Neurotransmisores/farmacología , Receptores de Dopamina D2/metabolismo , Transducción de Señal/efectos de los fármacos , Urocordados/inmunología , Animales , Dopamina/metabolismo , Filogenia
9.
Parasitology ; 148(8): 934-946, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33827719

RESUMEN

Trichomonas vaginalis is a parasite of the human urogenital tract and the causative agent of trichomoniasis, a sexually transmitted disease of worldwide importance. This parasite is usually found as a motile flagellated trophozoite. However, when subjected to stressful microenvironmental conditions, T. vaginalis trophozoites can differentiate into peculiar cyst-like stages, which exhibit notable physiological resistance to unfavourable conditions. Although well documented in morphological and proteomic terms, patterns of gene expression changes involved in the cellular differentiation into cyst-like stages are mostly unknown. The real-time reverse transcription polymerase chain reaction (RT-qPCR) is recognized as a sensitive and accurate method for quantification of gene expression, providing fluorescence-based data that are proportional to the amount of a target RNA. However, the reliability of relative expression studies depends on the validation of suitable reference genes, which RNAs exhibit a minimum of variation between tested conditions. Here, we attempt to determine suitable reference genes to be used as controls of invariant expression during cold-induced in vitro differentiation of T. vaginalis trophozoites into cyst-like forms. Furthermore, we reveal that the mRNA from the meiotic recombinase Dmc1 is upregulated during this process, indicating that cryptic sexual events may take place in cyst-like stages of T. vaginalis.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica/genética , Meiosis/genética , Trichomonas vaginalis/crecimiento & desarrollo , Trichomonas vaginalis/genética , Proteínas de Ciclo Celular/genética , Frío , Proteínas de Unión al ADN/genética , Humanos , ARN Mensajero/metabolismo , Valores de Referencia , Regulación hacia Arriba
10.
J ECT ; 37(1): 46-50, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32881781

RESUMEN

OBJECTIVES: Eliciting a generalized seizure is essential to electroconvulsive therapy (ECT), but there is still a need to understand how patient and session variables interact to generate a seizure of adequate quality. Here, we investigate factors associated with motor seizure length as a measure of quality in a large database of patients who underwent ECT. METHODS: This is a retrospective cohort including data from all adult inpatients who underwent ECT at a university hospital in Brazil from 2009 to 2015. We used linear mixed models to investigate the effects of patient, session, and medication on seizure length. RESULTS: Session information was available for 387 patients, a total of 3544 sessions and 4167 individual stimulations. Multiple stimulations were necessary in 12.4% of sessions. Median seizure length was 30 seconds. Seizure length was directly correlated with stimulus dosage and inversely correlated with the session number, patient age, prescription of anticonvulsants in the day before and ß-blockers during the session, and the thiopental dose. Use of benzodiazepines was not associated with a shorter seizure duration, irrespective of dose. CONCLUSIONS: We demonstrate here how motor seizure length evolves during a course of ECT. With a large number of sessions, we are able to integrate a host of factors in a prediction model. Seizure quality was influenced by a number of the studied factors, many of which are potentially modifiable and could be assessed before initiating and handled during treatment.


Asunto(s)
Terapia Electroconvulsiva/métodos , Convulsiones/etiología , Factores de Edad , Anticonvulsivantes/administración & dosificación , Brasil , Electroencefalografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Calidad de la Atención de Salud , Estudios Retrospectivos , Tiopental/administración & dosificación , Factores de Tiempo
11.
Trop Anim Health Prod ; 53(5): 472, 2021 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-34550484

RESUMEN

The aim of the present study was to evaluate whether the addition of red propolis extract (RPE), in different roughage: concentrate (R:C) ratios, influences the intake, digestibility, ruminal parameters, and serum biochemistry of sheep. We used eight Santa Inês sheep with an average body weight of 29.45 ± 1.58 kg, housed in metabolism cages for 60 days, and distributed in two simultaneous Latin square designs in a 2 × 2 factorial scheme. The factors consisted of two R:C ratios (70:30 and 30:70) with or without the addition of 15 mL/day of RPE. No interactions were found (P > 0.05) between R:C ratios and with or without RPE. Sheep fed 30:70 ratio showed higher (P < 0.05) intake and dry matter (DM) digestibility and non-fibrous carbohydrates and lower (P < 0.05) intake and neutral detergent fiber (NDF) digestibility. The addition of RPE did not influence (P > 0.05) the intake or nutrients digestibility, but the sheep that received RPE had a higher (P < 0.05) ruminal pH and longer (P < 0.05) time of rumination (min/kg DM) compared to the group without propolis. The ruminal ammonia concentration was higher for sheep fed 70:30 ratio, but the concentrations of total protein and albumin did not differ between R:C ratios. The addition of 15 mL of RPE does not influence the intake, digestibility, ingestive behavior, and rumen ammonical nitrogen of sheep. There is no association between the R:C ratio and the addition of 15 mL/day of RPE for sheep.


Asunto(s)
Fibras de la Dieta , Própolis , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Digestión , Extractos Vegetales , Própolis/farmacología , Ovinos , Oveja Doméstica
12.
PLoS Genet ; 13(7): e1006868, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28671979

RESUMEN

Gene regulatory networks (GRNs) evolve as a result of the coevolutionary processes acting on transcription factors (TFs) and the cis-regulatory modules they bind. The zinc-finger TF zelda (zld) is essential for the maternal-to-zygotic transition (MZT) in Drosophila melanogaster, where it directly binds over thousand cis-regulatory modules to regulate chromatin accessibility. D. melanogaster displays a long germ type of embryonic development, where all segments are simultaneously generated along the whole egg. However, it remains unclear if zld is also involved in the MZT of short-germ insects (including those from basal lineages) or in other biological processes. Here we show that zld is an innovation of the Pancrustacea lineage, being absent in more distant arthropods (e.g. chelicerates) and other organisms. To better understand zld´s ancestral function, we thoroughly investigated its roles in a short-germ beetle, Tribolium castaneum, using molecular biology and computational approaches. Our results demonstrate roles for zld not only during the MZT, but also in posterior segmentation and patterning of imaginal disc derived structures. Further, we also demonstrate that zld is critical for posterior segmentation in the hemipteran Rhodnius prolixus, indicating this function predates the origin of holometabolous insects and was subsequently lost in long-germ insects. Our results unveil new roles of zld in different biological contexts and suggest that changes in expression of zld (and probably other major TFs) are critical in the evolution of insect GRNs.


Asunto(s)
Proteínas de Drosophila/genética , Desarrollo Embrionario/genética , Evolución Molecular , Redes Reguladoras de Genes/genética , Factores de Transcripción/genética , Animales , Tipificación del Cuerpo/genética , Escarabajos/genética , Proteínas de Drosophila/biosíntesis , Drosophila melanogaster/genética , Drosophila melanogaster/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica , Proteínas Nucleares , Regiones Promotoras Genéticas , Interferencia de ARN , Factores de Transcripción/biosíntesis , Activación Transcripcional/genética , Alas de Animales/crecimiento & desarrollo
13.
J Prosthet Dent ; 123(6): 829-838, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31590983

RESUMEN

STATEMENT OF PROBLEM: The biomechanical behavior of post-restored roots with an experimental fiber-reinforced composite resin is unknown. PURPOSE: The purpose of this in vitro study was to investigate the biomechanical behavior of an experimental composite resin (3-mm short glass fiber incorporated in methacrylate matrix with filler particles) used to produce the custom post itself or to reline fiber posts. MATERIAL AND METHODS: Four testing groups (n=10) were created according to the root restoration method: FG, commercially available fiber post; FG+RC, fiber post relined with conventional composite resin; FG+EXP, fiber post relined with the experimental composite resin; and EXP, a custom post made of experimental composite resin. A three-dimensional finite element linear elastic analysis was performed by using geometric representations of groups, and the results were analyzed by von Mises (σvM) and maximum principal stress criteria. In sequence, 40 bovine incisors were assigned to these groups and subjected to a fracture load test (Instron 5965; 0.5 mm/min), and the failure mode was determined. RESULTS: The EXP group showed more homogeneous stress distribution for σvM. ANOVA and the Tukey honestly significant difference (HSD) tests showed significant differences (P<.001) in fracture load (mean ±standard deviation; different superscript letters indicate statistical difference): FG+EXP (669.5 ±107.7)A; FG (620.7 ±59.2)A; EXP (506.5 ±27.0)B; FG+RC (452.7 ±81.6)B. No differences were found for failure mode (P=.595). CONCLUSIONS: The experimental composite resin significantly increases fracture load when used to reline commercially available fiber posts and, irrespective of its use, presented lower stress concentration.


Asunto(s)
Técnica de Perno Muñón , Fracturas de los Dientes , Diente no Vital , Animales , Bovinos , Resinas Compuestas , Materiales Dentales , Análisis del Estrés Dental , Vidrio , Incisivo , Ensayo de Materiales
14.
Arch Insect Biochem Physiol ; 102(4): e21606, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31498484

RESUMEN

Polyphosphates (polyPs) have been found in all cell types examined to date and play diverse roles, depending on the cell type. In eukaryotic organisms, polyPs have been mainly investigated in mammalian cells, with few studies on insects. In this study, we investigated mitochondrial polyphosphate metabolism in the red flour beetle, Tribolium castaneum. Substrate specificity for different chain lengths demonstrated the presence of two exopolyphosphatase isoforms in mitochondria. T. castaneum mitochondrial polyP levels decreased after injection with soluble pyrophosphatase (Tc-sPPase) dsRNA, while the membrane exopolyphosphate activity increased. Mitochondrial respiration modulated exopolyphosphatase activity only in wild-type beetles. Tripolyphosphate was able to increase the F-ATPase activity in wild-type and Tc-sPPase RNAi beetles. We suggest that inorganic pyrophosphatase modulates polyphosphate metabolism in mitochondria and affects the link between mitochondrial activity and polyphosphate metabolism in T. castaneum.


Asunto(s)
Pirofosfatasa Inorgánica/metabolismo , Mitocondrias/metabolismo , Polifosfatos/metabolismo , Tribolium/enzimología , Adenosina Trifosfatasas , Animales , Femenino , Pirofosfatasa Inorgánica/química , Proteínas de Insectos/metabolismo , Masculino , Interferencia de ARN , Tribolium/metabolismo
15.
Soc Psychiatry Psychiatr Epidemiol ; 54(7): 857-860, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30895355

RESUMEN

PURPOSE: To evaluate changes in standardized suicide rates in Brazil between 2000 and 2016, stratified by sex and age. METHODS: Descriptive analyses of data from the Brazilian Mortality Information System were performed. RESULTS: 156,292 suicides were registered in the period, with a standardized rate of 4.82/100,000. The risk for males was 3.81 times higher than for females, without meaningful regional variations. This ratio was 8.2 at the 80+ group. An increase from 2000 to 2016 was demonstrated in nearly all subgroups over the 17, especially men aged 20-39 and women aged 40-59. CONCLUSIONS: Suicide rates continue to rise in Brazil, especially among young men and middle-aged women. Older men remain exposed to the highest absolute risk.


Asunto(s)
Suicidio/tendencias , Adolescente , Adulto , Distribución por Edad , Anciano , Brasil/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Distribución por Sexo , Adulto Joven
16.
Proc Natl Acad Sci U S A ; 112(48): 14936-41, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26627243

RESUMEN

Rhodnius prolixus not only has served as a model organism for the study of insect physiology, but also is a major vector of Chagas disease, an illness that affects approximately seven million people worldwide. We sequenced the genome of R. prolixus, generated assembled sequences covering 95% of the genome (∼ 702 Mb), including 15,456 putative protein-coding genes, and completed comprehensive genomic analyses of this obligate blood-feeding insect. Although immune-deficiency (IMD)-mediated immune responses were observed, R. prolixus putatively lacks key components of the IMD pathway, suggesting a reorganization of the canonical immune signaling network. Although both Toll and IMD effectors controlled intestinal microbiota, neither affected Trypanosoma cruzi, the causal agent of Chagas disease, implying the existence of evasion or tolerance mechanisms. R. prolixus has experienced an extensive loss of selenoprotein genes, with its repertoire reduced to only two proteins, one of which is a selenocysteine-based glutathione peroxidase, the first found in insects. The genome contained actively transcribed, horizontally transferred genes from Wolbachia sp., which showed evidence of codon use evolution toward the insect use pattern. Comparative protein analyses revealed many lineage-specific expansions and putative gene absences in R. prolixus, including tandem expansions of genes related to chemoreception, feeding, and digestion that possibly contributed to the evolution of a blood-feeding lifestyle. The genome assembly and these associated analyses provide critical information on the physiology and evolution of this important vector species and should be instrumental for the development of innovative disease control methods.


Asunto(s)
Adaptación Fisiológica/genética , Enfermedad de Chagas , Interacciones Huésped-Parásitos/genética , Insectos Vectores , Rhodnius , Trypanosoma cruzi/fisiología , Animales , Secuencia de Bases , Transferencia de Gen Horizontal , Humanos , Insectos Vectores/genética , Insectos Vectores/parasitología , Datos de Secuencia Molecular , Rhodnius/genética , Rhodnius/parasitología , Wolbachia/genética
17.
BMC Biol ; 15(1): 62, 2017 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-28756775

RESUMEN

BACKGROUND: The duplication of genes can occur through various mechanisms and is thought to make a major contribution to the evolutionary diversification of organisms. There is increasing evidence for a large-scale duplication of genes in some chelicerate lineages including two rounds of whole genome duplication (WGD) in horseshoe crabs. To investigate this further, we sequenced and analyzed the genome of the common house spider Parasteatoda tepidariorum. RESULTS: We found pervasive duplication of both coding and non-coding genes in this spider, including two clusters of Hox genes. Analysis of synteny conservation across the P. tepidariorum genome suggests that there has been an ancient WGD in spiders. Comparison with the genomes of other chelicerates, including that of the newly sequenced bark scorpion Centruroides sculpturatus, suggests that this event occurred in the common ancestor of spiders and scorpions, and is probably independent of the WGDs in horseshoe crabs. Furthermore, characterization of the sequence and expression of the Hox paralogs in P. tepidariorum suggests that many have been subject to neo-functionalization and/or sub-functionalization since their duplication. CONCLUSIONS: Our results reveal that spiders and scorpions are likely the descendants of a polyploid ancestor that lived more than 450 MYA. Given the extensive morphological diversity and ecological adaptations found among these animals, rivaling those of vertebrates, our study of the ancient WGD event in Arachnopulmonata provides a new comparative platform to explore common and divergent evolutionary outcomes of polyploidization events across eukaryotes.


Asunto(s)
Evolución Molecular , Duplicación de Gen , Genoma , Arañas/genética , Animales , Femenino , Masculino , Sintenía
18.
Genesis ; 55(5)2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28432834

RESUMEN

The development of a digestive system is an essential feature of bilaterians. Studies of the molecular control of gut formation in arthropods have been studied in detail in the fruit fly Drosophila melanogaster. However, little is known in other arthropods, especially in noninsect arthropods. To better understand the evolution of arthropod alimentary system, we investigate the molecular control of gut development in the spider Parasteatoda tepidariorum (Pt), the primary chelicerate model species for developmental studies. Orthologs of the ectodermal genes Pt-wingless (Pt-wg) and Pt-hedgehog (Pt-hh), of the endodermal genes, Pt-serpent (Pt-srp) and Pt-hepatocyte-nuclear factor-4 (Pt-hnf4) and of the mesodermal gene Pt-twist (Pt-twi) are expressed in the same germ layers during spider gut development as in D. melanogaster. Thus, our expression data suggest that the downstream molecular components involved in gut development in arthropods are conserved. However, Pt-forkhead (Pt-fkh) expression and function in spiders is considerably different from its D. melanogaster ortholog. Pt-fkh is expressed before gastrulation in a cell population that gives rise to endodermal and mesodermal precursors, suggesting a possible role for this factor in specification of both germ layers. To test this hypothesis, we knocked down Pt-fkh via RNA interference. Pt-fkh RNAi embryos not only fail to develop a proper gut, but also lack the mesodermal Pt-twi expressing cells. Thus, in spiders Pt-fkh specifies endodermal and mesodermal germ layers. We discuss the implications of these findings for the evolution and development of gut formation in Ecdysozoans.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Intestinos/embriología , Arañas/genética , Animales , Femenino , Estratos Germinativos/embriología , Estratos Germinativos/metabolismo , Mucosa Intestinal/metabolismo , Masculino , Arañas/embriología , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
19.
Genesis ; 55(5)2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28432816

RESUMEN

The hemiptera Rhodnius prolixus is a blood-feeding insect and a primary vector of Trypanosoma cruzi, the etiological agent of the Chagas disease. Over the past century, Rhodnius has been the subject of intense investigations, which have contributed to unveil important aspects of metabolism and physiology in insects. Recent technological innovations are helping dissect the genetic and molecular underpinnings of Rhodnius embryogenesis and organogenesis, thus fostering the use of this important species in the fields of developmental and evolutionary biology. Rhodnius represents also an excellent system to study development under stressful conditions, since the embryo must develop in the presence of a large amount of blood-derived reactive oxygen species. With a recently sequenced genome, small among other Hemiptera, and the identification of basic elements for all classical development pathways, functional studies in this species are revealing novel aspects of insect development and evolution. Here we review early studies on this model insect and how this paved the way for recent functional studies using the kissing bug.


Asunto(s)
Insectos Vectores/crecimiento & desarrollo , Rhodnius/crecimiento & desarrollo , Animales , Desarrollo Embrionario , Evolución Molecular , Insectos Vectores/genética , Insectos Vectores/fisiología , Rhodnius/genética , Rhodnius/fisiología
20.
J Exp Zool B Mol Dev Evol ; 328(1-2): 5-40, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27491339

RESUMEN

Famous for its blind cavefish and Darwin's finches, Latin America is home to some of the richest biodiversity hotspots of our planet. The Latin American fauna and flora inspired and captivated naturalists from the nineteenth and twentieth centuries, including such notable pioneers such as Fritz Müller, Florentino Ameghino, and Léon Croizat who made a significant contribution to the study of embryology and evolutionary thinking. But, what are the historical and present contributions of the Latin American scientific community to Evo-Devo? Here, we provide the first comprehensive overview of the Evo-Devo laboratories based in Latin America and describe current lines of research based on endemic species, focusing on body plans and patterning, systematics, physiology, computational modeling approaches, ecology, and domestication. Literature searches reveal that Evo-Devo in Latin America is still in its early days; while showing encouraging indicators of productivity, it has not stabilized yet, because it relies on few and sparsely distributed laboratories. Coping with the rapid changes in national scientific policies and contributing to solve social and health issues specific to each region are among the main challenges faced by Latin American researchers. The 2015 inaugural meeting of the Pan-American Society for Evolutionary Developmental Biology played a pivotal role in bringing together Latin American researchers eager to initiate and consolidate regional and worldwide collaborative networks. Such networks will undoubtedly advance research on the extremely high genetic and phenotypic biodiversity of Latin America, bound to be an almost infinite source of amazement and fascinating findings for the Evo-Devo community.


Asunto(s)
Evolución Biológica , Biología Evolutiva , Investigación , Animales , América Latina
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA