Agricultural insect pests as models for studying stress-induced evolutionary processes.

Agricultural insect pests (AIPs) are widely successful in adapting to natural and anthropogenic stressors, repeatedly overcoming population bottlenecks and acquiring resistance to intensive management practices. Although they have been largely overlooked in evolutionary studies, AIPs are ideal systems for understanding rapid adaptation under novel environmental conditions. Researchers have identified several genomic mechanisms that likely contribute to adaptive stress responses, including positive selection on de novo mutations, polygenic selection on standing allelic variation and phenotypic plasticity (e.g., hormesis). However, new theory suggests that stress itself may induce epigenetic modifications, which may confer heritable physiological changes (i.e., stress-resistant phenotypes). In this perspective, we discuss how environmental stress from agricultural management generates the epigenetic and genetic modifications that are associated with rapid adaptation in AIPs. We summarise existing evidence for stress-induced evolutionary processes in the context of insecticide resistance. Ultimately, we propose that studying AIPs offers new opportunities and resources for advancing our knowledge of stress-induced evolution.

Functional Dissection of the Chickpea (Cicer arietinum L.) Stay-Green Phenotype Associated with Molecular Variation at an Ortholog of Mendel's I Gene for Cotyledon Color: Implications for Crop Production and Carotenoid Biofortification.

"Stay-green" crop phenotypes have been shown to impact drought tolerance and nutritional content of several crops. We aimed to genetically describe and functionally dissect the particular stay-green phenomenon found in chickpeas with a green cotyledon color of mature dry seed and investigate its potential use for improvement of chickpea environmental adaptations and nutritional value. We examined 40 stay-green accessions and a set of 29 BC2F4-5 stay-green introgression lines using a stay-green donor parent ICC 16340 and two Indian elite cultivars (KAK2, JGK1) as recurrent parents. Genetic studies of segregating populations indicated that the green cotyledon trait is controlled by a single recessive gene that is invariantly associated with the delayed degreening (extended chlorophyll retention). We found that the chickpea ortholog of Mendel's I locus of garden pea, encoding a SGR protein as very likely to underlie the persistently green cotyledon color phenotype of chickpea. Further sequence characterization of this chickpea ortholog CaStGR1 (CaStGR1, for carietinum stay-green gene 1) revealed the presence of five different molecular variants (alleles), each of which is likely a loss-of-function of the chickpea protein (CaStGR1) involved in chlorophyll catabolism. We tested the wild type and green cotyledon lines for components of adaptations to dry environments and traits linked to agronomic performance in different experimental systems and different levels of water availability. We found that the plant processes linked to disrupted CaStGR1 gene did not functionality affect transpiration efficiency or water usage. Photosynthetic pigments in grains, including provitaminogenic carotenoids important for human nutrition, were 2-3-fold higher in the stay-green type. Agronomic performance did not appear to be correlated with the presence/absence of the stay-green allele. We conclude that allelic variation in chickpea CaStGR1 does not compromise traits linked to environmental adaptation and agronomic performance, and is a promising genetic technology for biofortification of provitaminogenic carotenoids in chickpea.

Cross-protection interactions in insect pests: Implications for pest management in a changing climate.

Agricultural insect pests display an exceptional ability to adapt quickly to natural and anthropogenic stressors. Emerging evidence suggests that frequent and varied sources of stress play an important role in driving protective physiological responses; therefore, intensively managed agroecosystems combined with climatic shifts might be an ideal crucible for stress adaptation. Cross-protection, where responses to one stressor offers protection against another type of stressor, has been well documented in many insect species, yet the molecular and epigenetic underpinnings that drive overlapping protective responses in insect pests remain unclear. In this perspective, we discuss cross-protection mechanisms and provide an argument for its potential role in increasing tolerance to a wide range of natural and anthropogenic stressors in agricultural insect pests. By drawing from existing literature on single and multiple stressor studies, we outline the processes that facilitate cross-protective interactions, including epigenetic modifications, which are understudied in insect stress responses. Finally, we discuss the implications of cross-protection for insect pest management, focusing on the consequences of cross-protection between insecticides and elevated temperatures associated with climate change. Given the multiple ways that insect pests are intensively managed in agroecosystems, we suggest that examining the role of multiple stressors can be important in understanding the wide adaptability of agricultural insect pests. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Rapid evolution of insecticide resistance in the Colorado potato beetle, Leptinotarsa decemlineata.

Despite considerable research, efforts to manage insecticide resistance continue to fail. The Colorado potato beetle (CPB), Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), epitomizes this problem, as it has repeatedly and rapidly evolved resistance to>50 insecticides. The patterns of resistance evolution are intriguing, as they defy models where resistance evolves from rare mutations. Here, we synthesize recent research on insecticide resistance in CPB showing that polygenic resistance drawn from standing genetic diversity explains genomic patterns of insecticide resistance evolution. However, rapid gene regulatory evolution suggests that other mechanisms might also facilitate adaptive change. We explore the hypothesis that sublethal stress from insecticide exposure could alter heritable epigenetic modifications, and discuss the range of experimental approaches needed to fully understand insecticide resistance evolution in this super pest.

Insecticide exposure affects intergenerational patterns of DNA methylation in the Colorado potato beetle, Leptinotarsa decemlineata.

Insecticide use is pervasive as a selective force in modern agroecosystems. Insect herbivores exposed to these insecticides have been able to rapidly evolve resistance to them, but how they are able to do so is poorly understood. One possible but largely unexplored explanation is that exposure to sublethal doses of insecticides may alter epigenetic patterns that are heritable. For instance, epigenetic mechanisms, such as DNA methylation that modifies gene expression without changing the underlying genetic code, may facilitate the emergence of resistant phenotypes in complex ways. We assessed the effects of sublethal insecticide exposure, with the neonicotinoid imidacloprid, on DNA methylation in the Colorado potato beetle, Leptinotarsa decemlineata, examining both global changes in DNA methylation and specific changes found within genes and transposable elements. We found that exposure to insecticide led to decreases in global DNA methylation for parent and F2 generations and that many of the sites of changes in methylation are found within genes associated with insecticide resistance, such as cytochrome P450s, or within transposable elements. Exposure to sublethal doses of insecticide caused heritable changes in DNA methylation in an agricultural insect herbivore. Therefore, epigenetics may play a role in insecticide resistance, highlighting a fundamental mechanism of evolution while informing how we might better coexist with insect species in agroecosystems.

The Impact of Domestication on Aboveground and Belowground Trait Responses to Nitrogen Fertilization in Wild and Cultivated Genotypes of Chickpea (Cicer sp.).

Despite the importance of crop responses to low fertility conditions, few studies have examined the extent to which domestication may have limited crop responses to low-fertility environments in aboveground and belowground traits. Moreover, studies that have addressed this topic have used a limited number of wild accessions, therefore overlooking the genotypic and phenotypic diversity of wild relatives. To examine how domestication has affected the response of aboveground and belowground agronomic traits, we measured root and leaf functional traits in an extensive set of wild and domesticated chickpea accessions grown in low and high nitrogen soil environments. Unlike previous studies, the wild accessions used in this study broadly capture the genetic and phenotypic diversity of domesticated chickpea's (Cicer arietinum) closest compatible wild relative (C. reticulatum). Our results suggest that the domestication of chickpea led to greater capacities for plasticity in morphological and biomass related traits but may have lowered the capacity to modify physiological traits related to gas exchange. Wild chickpea displayed greater phenotypic plasticity for physiological traits including stomatal conductance, canopy level photosynthesis, leaf level photosynthesis, and leaf C/N ratio. In contrast to domesticated chickpea, wild chickpea displayed phenotypes consistent with water loss prevention, by exhibiting lower specific leaf area, stomatal conductance and maintaining efficient water-use. In addition to these general patterns, our results indicate that the domestication dampened the variation in response type to higher nitrogen environments for belowground and aboveground traits, which suggests reduced genetic diversity in current crop germplasm collections.

Genetic diversity of Chamaecrista fasciculata (Fabaceae) from the USDA germplasm collection.

OBJECTIVE: Chamaecrista fasciculata is a widespread annual legume across Eastern North America, with potential as a restoration planting, biofuel crop, and genetic model for non-papillinoid legumes. As a non-Papilinoid, C. fasciculata, belongs to the Caesalpiniod group in which nodulation likely arose independently of the nodulation in Papilinoid and Mimosoid legumes. Thus, C. fasciculata is an attractive model system for legume evolution. In this study, we describe population structure and genetic diversity among 32 USDA germplasm accessions of C. fasciculata using 317 AFLP markers developed from 12 primer pairs, to assess where geographically there is the most genetic variation. RESULTS: We found that the C. fasciculata germplasm collection fall into four clusters with admixture among them. After correcting for outliers, our analysis shows two primary groups across Eastern and Central North America. To better understand the population biology of this species, further sampling of the full range of this widespread species is needed across North America, as well as the development of a larger set of markers providing denser coverage of the genome. Further sampling will help clarify geographical relationships in this widespread temperate species.

Actualidad en el manejo clínico del derrame pleural maligno: revisión narrativa / Update on the clinical management of malignant pleural effusion: narrative review: A narrative review

Introducción: Cerca del 50 % de los derrames pleurales (DP) es neoplásico. El comportamiento clínico del DP neoplásico es altamente sintomático por el gran volumen y su recidiva temprana. Propósito de la revisión: El objetivo de la revisión es delinear el papel de los diferentes métodos diagnósticos y terapéuticos de DP maligno. Buscamos reportes actualizados en donde se incluye los resultados de mejor supervivencia para los distintos tratamientos actuales. Recientes hallazgos: Los criterios de Light es el método estándar para diferenciar un exudado maligno. La toracocentesis guiada por ultrasonido debe ser usada como método diagnóstico/terapéutico. En pacientes con DP maligno se recomienda el drenaje permanente con el posicionamiento de un tubo de tórax y un sello hidráulico con drenaje cerrado. La pleurodesia con instilación de talco está recomendada en pacientes con DP maligno en busca de disminuir el volumen, las recidivas del DP y el tiempo de hospitalización. Conclusiones: Para el correcto manejo del DP maligno, hay que tomar en cuenta varios aspectos, como identificar la presencia de células malignas mediante estudio citológico y descartar una infección. La ecografía pleural permite definir el volumen del DP y permite decidir drenaje en ese momento, con la posibilidad de inserción de catéter intrapleural, con el objetivo de evaluar la posibilidad de esclerosar las pleuras a través de pleurodesia. Sin embargo, para llegar a esta decisión hay que analizar cada uno de los detalles que podrían tener un papel de importancia para el buen manejo y resolución definitiva o por el contrario decidir el manejo a título paliativo, siempre analizando cada caso con el objetivo de proveer de mejoría de síntomas y mejorar la calidad de vida del paciente.

Introduction: Approximately 50% of pleural effusions (PE) are neoplastic. The clinical behavior of neoplastic PE is highly symptomatic due to its large volume and early recurrence. Purpose of review: This review aims to outline the role of the different diagnostic and therapeutic methods of malignant PE. We look for updated reports that include the best survival results for the other current treatments. Recent findings: Light's criteria are the standard to differentiate a malignant exudate. Ultrasound-guided thoracentesis should be used as a diagnostic/therapeutic method. In patients with malignant PE, permanent drainage is recommended with the placement of a chest tube and a hydraulic seal with closed drainage. Pleurodesis with the installation of talc is recommended in patients with malignant PE to reduce volume, PE recurrences, and hospitalization time. Conclusions: For the correct management of malignant PE, several aspects must be considered, such as identifying the presence of malignant cells by cytological study and ruling out infection. Pleural ultrasound allows for defining the volume of the PE. It will enable deciding on drainage at that time, with the possibility of inserting an intrapleural catheter, to evaluate the likelihood of sclerosing the pleurae through pleurodesis. However, to reach this decision, it is necessary to analyze each of the details that could play an essential role in good management and definitive resolution or, on the contrary, decide on palliative management, constantly investigating each case to provide symptom improvement. In addition, improving the patient's quality of life.

Common postburn deformities and their management.

This article describes a practical, clinically based approach to classification of postburn deformities. Burn scar contractures are of either the broad diffuse type or linear band-like type. The former generally respond well to release and insertion of a skin graft or substitute, whereas the latter are generally repaired using a simple or modified Z-plasty or a transpositional flap technique. The pulsed dye laser is a promising technique used to reduce scar thickness and redness. Postburn deformities of the face, upper and lower extremities, and trunk are discussed, in addition to novel techniques for vascularized composite allotransplantation of the face.

Manejo de la hemorragia subaracnoidea en pacientes ingresados en el área de Neurocirugía del hospital Dr. Teodoro Maldonado Carbo, 01 de enero al 31 de julio de 2002 / I manage of the hemorragia subaracnoidea in patients entered in the area of Neurosurgery of the Dr. Teodoro Maldonado Carbo Hospital, January 1st to July 31 of 2002

Estudio realizado en el servicio de Neurocirugía del hospital “Dr. Teodoro Maldonado Carbo” durante 1 enero-31 julio 2002. Fueron 118 pacientes ingresados de los cuales se tomaron 16 pacientes que cumplieron con los criterios de inclusión y que por tanto se constituye en universo.Tipo de estudio: retrospectivo, descriptivo.Objetivos. General:Determinar cómo se realiza el manejo de los pacientes con hemorragia subaracnoidea ingresados en el servicio de Neurocirugía.Específicos:1.- Establecer por medio de porcentajes la morbimortalidad de los pacientes que cursan con Hemorragia Subaracnoidea.2.- Determinar la influencia que ejercen los antecedentes personales y hábitos de este grupo de pacientes.Resultados: De los 16 pacientes la patología determinada se presentó el 49% en mayores de 60 años; prevaleciendo también en el sexo masculino que alcanzó el 62%. En cuanto a los pacientes con antecedentes de hipertensión arterial se destacó el 25%, aún en aquellos individuos que seguían un tratamiento adecuado. En cuanto a la etiología se destacó el trauma cráneo encefálico con un 44%, seguido de los aneurismas con un 25%. Como medio de diagnóstico, la tomografía axial computarizada, con el 81%, demostró que sigue siendo el de primera elección. El tratamiento conservador alcanzó el 75% y en nuestro universo de estudio se obtuvo 62% de mejoría y 38% curación al momento del alta hospitalaria.Conclusiones: Se logró demostrar con este estudio el adecuado y eficaz manejo intra hospitalario para con este grupo de pacientes, no sólo con el hecho del alto porcentaje en el tratamiento conservador sino también porque no existió ningún paciente fallecido en nuestro universo de estudio.

Study carried out in the Service of Neurosurgery at the Dr. Teodoro Maldonado Carbo Hospital during January 1st to 31 July 2002. They were 118 entered patients of which took 16 patients that fulfilled the approaches. Therefore the universe of our study belongs to 16 patients. Study type: retrospective, descriptive.Objectives. General: To determine like he/she is carried out the handling of the patients with Hemorragia Subaracnoidea entered in the service of Neurosurgery.Specific:1. - to settle down by means of percentages the morbimortalidad of the patients that study with Hemorragia Subaracnoidea.2. - to determine the influence that you/they exercise the personal antecedents and habits of this group of patients that have presented Hemorragia Subaracnoidea. Results: Of the 16 patients that entered with diagnosis of Hemorragia Subaracnoidea, 49% was obtained in bigger than 60 years, also prevailing in the masculine sex that reached 62%. As for the patients with antecedents of arterial Hypertension stood out even 25% in those individuals that followed an appropriate treatment. As for the etiología he/she stood out the Trauma skull encefálico with 44%, followed by the Aneurismas with 25%. Like half of diagnosis, the On-line Axial Tomografía with 81% demonstrated that it continues being the first election in this group of patient. The conservative treatment reached 75% and in our study universe it was obtained 62% of improvement and 38% cure to the hospital moment of the high one.Conclusions: It was possible to demonstrate with this study the appropriate and effective I manage hospital intra towards this group of patient, not only with the fact of the high percentage in the conservative treatment but also because any patient deceased didn't exist in our study universe.

Trauma penetrante de abdomen por arma cortopunzante, y órganos más frecuentemente lesionados. Emergencia del hospital Luis Vernaza, Guayaquil: Enero–junio 2002 / Penetrating trauma of abdomen by a sharp object, and organs but frequently injured. Emergency of the hospital Luis Vernaza, Guayaquil: January-June 2002

Estudio realizado en el área de emergencia del hospital Luis Vernaza de Guayaquil, durante el período de enero–junio 2002. Se escogieron 50 pacientes que ingresaban por trauma penetrante de abdomen por arma cortopunzante.Tipo de estudio: retrospectivo, longitudinal, descriptivo.Objetivos: General: Conocer los órganos mas lesionados en trauma abdominal penetrante por arma cortopunzante.Específicos: 1.Dar atención oportuna y eficaz.2.Instituir el tratamiento oportuno y correcto.3.Identificar la técnica más empleada en pacientes con trauma penetrante abdominal por arma cortopunzante. Resultados: De los 50 pacientes estudiados, el sexo más común fue el masculino, con 44 casos (88%), y la edad 15–20 años en 16 casos (32%), y el órgano más afectado el intestino delgado (yeyuno e íleon) 13 casos (26%). Aunque existió el mismo número de pacientes tratados quirúrgicamente con reporte de órganos indemnes (26%).Conclusiones: Se logró comprobar que el órgano mas afectado resultó el intestino delgado (yeyuno e íleon), cuyo tratamiento fue el de la sutura transversal para las pequeñas perforaciones, y resecciones parciales para perforaciones mayores.

A study carried at the emergency room of the Luis Vernaza hospital of Guayaquil, during the period of January - June of the 2002. 50 patients were chosen that entered for penetrating trauma of abdomen with a sharp object. Study type: Retrospective, descriptive, longitudinal. Objectives: General: to know the organs frequently injured in an abdominal trauma due to injury by sharp object.Specific: 1.To give opportune and effective attention. 2.To institute the opportune and correct treatment 3.To identify the technique employed in patients with abdominal trauma. Results: Of the 50 studied patients, common male sex with 44 cases (88%), and the in ages between 15-20 years in 16 cases (32%), and the organ most affected was the small intestine 13 cases (26%). Conclusions: The organ most affected is the small intestine whose treatment was that of the traverse suture for the small perforations, and partial resections for the big perforations.