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1.
Mol Cell ; 81(18): 3675-3676, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34547232

RESUMO

We highlight Martinez-Miguel et al. (2021), which demonstrates that an amino acid substitution in RPS23 found in thermophilic archaea contributes to increased translation fidelity, lifespan, and stress response but slows development and reproduction in other organisms.


Assuntos
Longevidade , Reprodução , Longevidade/genética
3.
J Am Chem Soc ; 146(23): 15688-15692, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38815061

RESUMO

We report the direct and accurate spectroscopic quantification of the inverted singlet-triplet gap in 1,3,4,6,9b-pentaazaphenalene. This measurement is achieved by directly probing the lowest singlet and triplet states via high-resolution cryogenic anion photoelectron spectroscopy. The assignment of the first excited singlet state is confirmed by visible absorption spectroscopy in an argon matrix at 20 K. Our measurements yield an inverted singlet-triplet gap with ΔEST= -0.047(7) eV. The accurate quantification of the singlet-triplet gap presented here allows for direct evaluation of various computational electronic structure methods and highlights the critical importance of the proper description of the double excitation character of these electronic states. Overall, this study validates the idea that despite Hund's multiplicity rule, useful organic chromophores can have inherently inverted singlet-triplet gaps.

4.
Mol Biol Evol ; 40(5)2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37155936

RESUMO

Understanding the genetic basis of pest adaptive evolution and the risk of adaptation in response to climate change is essential for the development of sustainable agricultural practices. However, the genetic basis of climatic adaptation for the Asian corn borer (ACB), Ostrinia furnacalis, the main pest of corn in Asia and Oceania, is poorly understood. Here, we revealed the genomic loci underlying the climatic adaptation and evolution in ACB by integrating population genomic and environmental factors. We assembled a 471-Mb chromosome-scale reference genome of ACB and resequenced 423 individuals covering 27 representative geographic areas. We inferred that the ACB effective population size changes tracked with the global temperature and followed by a recent decline. Based on an integrated analysis of whole-genome selection scans and genome-wide genotype-environment association studies, we revealed the genetic basis of ACB adaption to diverse climates. For diapause traits, we identified a major effect association locus containing a circadian clock gene (period) by analyzing a diapause-segregating population. Moreover, our predictions indicated that the northern populations were more ecologically resilient to climate change than the southern populations. Together, our results revealed the genomic basis for ACB environmental adaptation and provided potential candidate genes for future evolutionary studies and genetic adaptation to climate change, intending to maintain the efficacy and sustainability of novel control techniques.


Assuntos
Mariposas , Zea mays , Animais , Zea mays/genética , Metagenômica , Biodiversidade , Temperatura , Mariposas/genética , Ásia
5.
Hum Mol Genet ; 31(17): 2989-3000, 2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-35419606

RESUMO

Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by reduced expression of the survival motor neuron (SMN) protein. Current disease-modifying therapies increase SMN levels and dramatically improve survival and motor function of SMA patients. Nevertheless, current treatments are not cures and autopsy data suggest that SMN induction is variable. Our group and others have shown that combinatorial approaches that target different modalities can improve outcomes in rodent models of SMA. Here we explore if slowing SMN protein degradation and correcting SMN splicing defects could synergistically increase SMN production and improve the SMA phenotype in model mice. We show that co-administering ML372, which inhibits SMN ubiquitination, with an SMN-modifying antisense oligonucleotide (ASO) increases SMN production in SMA cells and model mice. In addition, we observed improved spinal cord, neuromuscular junction and muscle pathology when ML372 and the ASO were administered in combination. Importantly, the combinatorial approach resulted in increased motor function and extended survival of SMA mice. Our results demonstrate that a combination of treatment modalities synergistically increases SMN levels and improves pathophysiology of SMA model mice over individual treatment.


Assuntos
Atrofia Muscular Espinal , Doenças Neurodegenerativas , Animais , Modelos Animais de Doenças , Camundongos , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/patologia , Atrofia Muscular Espinal/terapia , Oligonucleotídeos/farmacologia , Oligonucleotídeos Antissenso/farmacologia , Proteína 1 de Sobrevivência do Neurônio Motor/genética
6.
Ann Surg ; 280(1): 29-31, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38451832

RESUMO

OBJECTIVE: The purpose of this surgical perspective is to describe the trauma care needs of the South Side of Chicago and the creation of an adult trauma center at the University of Chicago Medicine and associated hospital-based violence intervention program. BACKGROUND: Traumatic injury is a leading cause of death and disability in the United States. Disparities across the continuum of trauma care exist, which are often rooted in the social determinants of health. Trauma center distribution is critical to timely treatment and should be based on the trauma needs of the area. The previous trauma ecosystem of Chicago was incongruent with the concentration of violent injuries on the south and west sides of the city, leading to a fallacy of distributive justice. METHODS: A descriptive analysis of community partners, trauma program leadership, trauma surgeons, and the violence intervention program director was performed. RESULTS: The UCM trauma center opened in May 2018 and has since been one of the busiest trauma centers in the country, with a 40% penetrating trauma rate. There have been significant reductions in patient transport time on the South Side up to 8.9 minutes ( P <0.001). The violence intervention program employs credible messengers with lived experience representing the community and has engaged over 8000 patients since 2018, developing both community-based and medical-legal partnerships. CONCLUSIONS: The persistent efforts of the community and key stakeholders led to a system change that improved trauma care for the South Side of Chicago.


Assuntos
Acessibilidade aos Serviços de Saúde , Centros de Traumatologia , Humanos , Chicago , Acessibilidade aos Serviços de Saúde/ética , Ferimentos e Lesões/cirurgia , Ferimentos e Lesões/terapia , Violência , Disparidades em Assistência à Saúde
7.
New Phytol ; 243(4): 1539-1553, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39021237

RESUMO

The interactions among plant viruses, insect vectors, and host plants have been well studied; however, the roles of insect viruses in this system have largely been neglected. We investigated the effects of MpnDV infection on aphid and PVY transmission using bioassays, RNA interference (RNAi), and GC-MS methods and green peach aphid (Myzus persicae (Sulzer)), potato virus Y (PVY), and densovirus (Myzus persicae nicotianae densovirus, MpnDV) as model systems. MpnDV increased the activities of its host, promoting population dispersal and leading to significant proliferation in tobacco plants by significantly enhancing the titer of the sesquiterpene (E)-ß-farnesene (EßF) via up-regulation of expression levels of the MpFPPS1 gene. The proliferation and dispersal of MpnDV-positive individuals were faster than that of MpnDV-negative individuals in PVY-infected tobacco plants, which promoted the transmission of PVY. These results combined showed that an insect virus may facilitate the transmission of a plant virus by enhancing the locomotor activity and population proliferation of insect vectors. These findings provide novel opportunities for controlling insect vectors and plant viruses, which can be used in the development of novel management strategies.


Assuntos
Afídeos , Densovirus , Nicotiana , Doenças das Plantas , Afídeos/virologia , Afídeos/fisiologia , Animais , Nicotiana/virologia , Nicotiana/parasitologia , Doenças das Plantas/virologia , Densovirus/fisiologia , Densovirus/genética , Potyvirus/fisiologia , Potyvirus/patogenicidade , Sesquiterpenos/metabolismo , Vírus de Plantas/fisiologia , Vírus de Plantas/patogenicidade
8.
Plant Cell ; 33(9): 3151-3175, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34181022

RESUMO

The actin cytoskeleton regulates an array of diverse cellular activities that support the establishment of plant-microbe interactions and plays a critical role in the execution of plant immunity. However, molecular and cellular mechanisms regulating the assembly and rearrangement of actin filaments (AFs) at plant-pathogen interaction sites remain largely elusive. Here, using live-cell imaging, we show that one of the earliest cellular responses in Arabidopsis thaliana upon powdery mildew attack is the formation of patch-like AF structures beneath fungal invasion sites. The AFs constituting actin patches undergo rapid turnover, which is regulated by the actin-related protein (ARP)2/3 complex and its activator, the WAVE/SCAR regulatory complex (W/SRC). The focal accumulation of phosphatidylinositol-4,5-bisphosphate at fungal penetration sites appears to be a crucial upstream modulator of the W/SRC-ARP2/3 pathway-mediated actin patch formation. Knockout of W/SRC-ARP2/3 pathway subunits partially compromised penetration resistance with impaired endocytic recycling of the defense-associated t-SNARE protein PEN1 and its deposition into apoplastic papillae. Simultaneously knocking out ARP3 and knocking down the Class I formin (AtFH1) abolished actin patch formation, severely impaired the deposition of cell wall appositions, and promoted powdery mildew entry into host cells. Our results demonstrate that the ARP2/3 complex and formins, two actin-nucleating systems, act cooperatively and contribute to Arabidopsis penetration resistance to fungal invasion.


Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Proteínas de Arabidopsis/genética , Arabidopsis/imunologia , Ascomicetos/fisiologia , Forminas/metabolismo , Doenças das Plantas/imunologia , Imunidade Vegetal/genética , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Arabidopsis/microbiologia , Proteínas de Arabidopsis/metabolismo , Resistência à Doença/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia
9.
BMC Biol ; 21(1): 2, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36600240

RESUMO

BACKGROUND: The black cutworm, Agrotis ipsilon, is a serious global underground pest. Its distinct phenotypic traits, especially its polyphagy and ability to migrate long distances, contribute to its widening distribution and increasing difficulty of control. However, knowledge about these traits is still limited. RESULTS: We generated a high-quality chromosome-level assembly of A. ipsilon using PacBio and Hi-C technology with a contig N50 length of ~ 6.7 Mb. Comparative genomic and transcriptomic analyses showed that detoxification-associated gene families were highly expanded and induced after insects fed on specific host plants. Knockout of genes that encoded two induced ABC transporters using CRISPR/Cas9 significantly reduced larval growth rate, consistent with their contribution to host adaptation. A comparative transcriptomic analysis between tethered-flight moths and migrating moths showed expression changes in the circadian rhythm gene AiCry2 involved in sensing photoperiod variations and may receipt magnetic fields accompanied by MagR and in genes that regulate the juvenile hormone pathway and energy metabolism, all involved in migration processes. CONCLUSIONS: This study provides valuable genomic resources for elucidating the mechanisms involved in moth migration and developing innovative control strategies.


Assuntos
Mariposas , Animais , Estações do Ano , Mariposas/genética , Larva , Perfilação da Expressão Gênica , Cromossomos
10.
Ann Surg ; 277(1): 66-72, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35997268

RESUMO

OBJECTIVE: The aim of this review was to review the ethical and multidisciplinary clinical challenges facing trauma surgeons when resuscitating patients presenting with penetrating brain injury (PBI) and multicavitary trauma. BACKGROUND: While there is a significant gap in the literature on managing PBI in patients presenting with multisystem trauma, recent data demonstrate that resuscitation and prognostic features for such patients remains poorly described, with trauma guidelines out of date in this field. METHODS: We reviewed a combination of recent multidisciplinary evidence-informed guidelines for PBI and coupled this with expert opinion from trauma, neurosurgery, neurocritical care, pediatric and transplant surgery, surgical ethics and importantly our community partners. RESULTS: Traditional prognostic signs utilized in traumatic brain injury may not be applicable to PBI with a multidisciplinary team approach suggested on a case-by-case basis. Even with no role for neurosurgical intervention, neurocritical care, and neurointerventional support may be warranted, in parallel to multicavitary operative intervention. Special considerations should be afforded for pediatric PBI. Ethical considerations center on providing the patient with the best chance of survival. Consideration of organ donation should be considered as part of the continuum of patient, proxy and family-centric support and care. Community input is crucial in guiding decision making or protocol establishment on an institutional level. CONCLUSIONS: Support of the patient after multicavitary PBI can be complex and is best addressed in a multidisciplinary fashion with extensive community involvement.


Assuntos
Lesões Encefálicas Traumáticas , Traumatismos Cranianos Penetrantes , Obtenção de Tecidos e Órgãos , Humanos , Criança , Ressuscitação/métodos , Procedimentos Neurocirúrgicos
11.
Mol Ecol ; 32(20): 5463-5478, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37638537

RESUMO

The major plant pest fall armyworm (FAW), Spodoptera frugiperda, is native to the Americas and has colonized Africa and Asia within the Eastern hemisphere since 2016, causing severe damage to multiple agricultural crop species. However, the genetic origin of these invasive populations requires more in-depth exploration. We analysed genetic variation across the genomes of 280 FAW individuals from both the Eastern hemisphere and the Americas. The global range-wide genetic structure of FAW shows that the FAW in America has experienced deep differentiation, largely consistent with the Z-chromosomal Tpi haplotypes commonly used to differentiate 'corn-strain' and 'rice-strain' populations. The invasive populations from Africa and Asia are different from the American ones and have a relatively homogeneous population structure, consistent with the common origin and recent spreading from Africa to Asia. Our analyses suggest that north- and central American 'corn-strain' FAW are the most likely sources of the invasion into the Eastern hemisphere. Furthermore, evidence based on genomic, transcriptomic and mitochondrial haplotype network analyses indicates an earlier, independent introduction of FAW into Africa, with subsequent migration into the recent invasive population.

12.
J Exp Biol ; 226(24)2023 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-38095228

RESUMO

Insects are the most diverse animal group on the planet. Their success is reflected by the diversity of habitats in which they live. However, these habitats have undergone great changes in recent decades; understanding how these changes affect insect health and fitness is an important challenge for insect conservation. In this Review, we focus on the research that links the nutritional environment with infection and immune status in insects. We first discuss the research from the field of nutritional immunology, and we then investigate how factors such as intracellular and extracellular symbionts, sociality and transgenerational effects may interact with the connection between nutrition and immunity. We show that the interactions between nutrition and resistance can be highly specific to insect species and/or infection type - this is almost certainly due to the diversity of insect social interactions and life cycles, and the varied environments in which insects live. Hence, these connections cannot be easily generalised across insects. We finally suggest that other environmental aspects - such as the use of agrochemicals and climatic factors - might also influence the interaction between nutrition and resistance, and highlight how research on these is essential.


Assuntos
Insetos , Estado Nutricional , Animais
13.
J Surg Res ; 283: 259-265, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36423474

RESUMO

INTRODUCTION: Self-inflicted injuries are the second leading cause of pediatric (10-18 y old) mortality. Self-inflicted firearm trauma (SIFT) was responsible for up to half of these deaths in certain age groups. We hypothesized that SIFT prevalence has increased and is associated with specific demographics, injury patterns, and outcomes. MATERIALS AND METHODS: Data were abstracted from the 2007-2018 American College of Surgeons (ACS) Trauma Quality Programs Participant Use Files (TQP-PUF). Pediatric (1-17 yold) victims of firearm violence were eligible. Age, race, gender, anatomic region, and intent were abstracted. Variables were analyzed using chi-squared tests, t-tests, and single-variate linear regression models. Temporal trends were analyzed using ANCOVA tests. Multivariate logistic regressions were conducted to identify factors influencing mortality. Significance was P < 0.05. RESULTS: There were 41,239 pediatric firearm trauma patients (SIFT: 5.5% [n = 2272]). SIFT incidence increased over the 12-y period (2007 (n = 67) versus 2018 (n = 232), P < 0.05). SIFT was significantly associated with Caucasian race, 67% (n = 1537), teenagers, 90% (n = 2056), male gender, 87% (n = 1978), and a higher median injury severity score (ISS) than other intents of injury (SIFT: 20.0 (IQR: 9.0, 25.0) versus other: 9.0 (IQR: 1.0-13.0), P < 0.001). The SIFT mortality rate was 44% (n = 1005). On multivariate regression head gunshot wounds (OR: 21.1, 95% C.I.: 9.9-45.2, P = 0.001), and ISS (OR:1.1, 95% C.I.: 1.1-1.1, P = 0.001) were significantly associated with mortality. Compared to other intents, SIFT mortality rates increased at a higher annual rate (P < 0.001). CONCLUSIONS: Comprehensive local and federal policy changes to reduce firearms access and increase pediatric mental health support may mitigate these injuries.


Assuntos
Armas de Fogo , Ferimentos por Arma de Fogo , Adolescente , Criança , Humanos , Masculino , Ferimentos por Arma de Fogo/epidemiologia , Escala de Gravidade do Ferimento , Violência , População Branca , Estudos Retrospectivos
14.
PLoS Genet ; 16(7): e1008835, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32644988

RESUMO

In most organisms, dietary restriction (DR) increases lifespan. However, several studies have found that genotypes within the same species vary widely in how they respond to DR. To explore the mechanisms underlying this variation, we exposed 178 inbred Drosophila melanogaster lines to a DR or ad libitum (AL) diet, and measured a panel of 105 metabolites under both diets. Twenty four out of 105 metabolites were associated with the magnitude of the lifespan response. These included proteinogenic amino acids and metabolites involved in α-ketoglutarate (α-KG)/glutamine metabolism. We confirm the role of α-KG/glutamine synthesis pathways in the DR response through genetic manipulations. We used covariance network analysis to investigate diet-dependent interactions between metabolites, identifying the essential amino acids threonine and arginine as "hub" metabolites in the DR response. Finally, we employ a novel metabolic and genetic bipartite network analysis to reveal multiple genes that influence DR lifespan response, some of which have not previously been implicated in DR regulation. One of these is CCHa2R, a gene that encodes a neuropeptide receptor that influences satiety response and insulin signaling. Across the lines, variation in an intronic single nucleotide variant of CCHa2R correlated with variation in levels of five metabolites, all of which in turn were correlated with DR lifespan response. Inhibition of adult CCHa2R expression extended DR lifespan of flies, confirming the role of CCHa2R in lifespan response. These results provide support for the power of combined genomic and metabolomic analysis to identify key pathways underlying variation in this complex quantitative trait.


Assuntos
Envelhecimento/genética , Proteínas de Drosophila/genética , Longevidade/genética , Metaboloma/genética , Receptores Acoplados a Proteínas G/genética , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Restrição Calórica , Dieta , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento/genética , Insulina/genética , Metabolômica , Mutação/genética , Transdução de Sinais/genética
15.
J Allergy Clin Immunol ; 149(3): 1010-1017.e10, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34425177

RESUMO

BACKGROUND: Acute increases of ≥20% + 2 ng/mL (20 + 2 rule) over basal serum tryptase (BST) is the recommended threshold supporting a clinical diagnosis of anaphylaxis. Prospective studies have demonstrated high sensitivity for this algorithm after parenteral exposure, but specificity has not been evaluated. OBJECTIVE: We sought to define a serum tryptase change that distinguishes baseline variability from anaphylaxis on the basis of intraindividual variation in BST. METHODS: Ninety-three total subjects with atopy (n = 62) or hereditary α-tryptasemia (HαT) (n = 31) and ≥2 BST measurements were identified. Sequential BST variability measurements were modeled and threshold ratios that optimized sensitivity and/or specificity determined. Models were tested in 22 individuals with physician-diagnosed anaphylaxis and validated in independent cohorts of individuals with HαT (n = 33), indolent systemic mastocytosis (ISM) (n = 52), and ISM + HαT (n = 12). Mature tryptase levels were measured in HαT (n = 19) and ISM (n = 20). An online application was developed for clinical use. RESULTS: As a result of BST variability, 9.7% (9/93) of primary cohort patients, and 18% (6/33) of HαT, 30% (16/53) of ISM, and 25% (3/12) of ISM + HαT patients from validation cohorts met the 20 + 2 rule despite absent immediate hypersensitivity symptoms; mature tryptase was noncontributory among individuals with HαT or ISM at baseline. A ratio of acute tryptase/BST exceeding 1.685 provided the optimized diagnostic rule for jointly maximizing sensitivity and specificity. Statistically significant improvement in specificity relative to the 20 + 2 rule was observed among individuals with elevated BST caused by HαT and ISM. CONCLUSIONS: Using an acute tryptase/BST ratio of 1.685 improves specificity of measured changes among individuals with HαT and ISM while maintaining high sensitivity for confirmation of anaphylaxis.


Assuntos
Anafilaxia , Mastocitose Sistêmica , Mastocitose , Anafilaxia/diagnóstico , Humanos , Mastócitos , Estudos Prospectivos , Triptases
16.
BMC Genomics ; 23(1): 353, 2022 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-35525948

RESUMO

BACKGROUND: The cotton leafworm, Spodoptera littoralis, is a highly polyphagous pest of many cultivated plants and crops in Africa and Europe. The genome of this pest will help us to further understand the molecular mechanisms of polyphagy. RESULTS: Herein, the high-quality genome of S. littoralis was obtained by Pacific Bioscience (PacBio) sequencing. The assembled genome size of S. littoralis is 436.55 Mb with a scaffold N50 of 6.09 Mb, consisting of 17,207 annotated protein-coding genes. Phylogenetic analysis shows that S. littoralis and its sibling species S. litura diverged about 5.44 million years ago. Expanded gene families were mainly involved in metabolic detoxification and tolerance to toxic xenobiotics based on GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis. Comparative genomics analysis showed that gene families involved in detoxification and chemosensation were significantly expanded in S. littoralis, representing genetic characteristics related to polyphagy and an extensive host range. CONCLUSIONS: We assembled and annotated the reference genome of S. littoralis, and revealed that this pest has the genetic features of strong detoxification capacity, consistent with it being a significant risk to a wide range of host crops. These data resources will provide support for risk assessment and early warning monitoring of major polyphagous agricultural pests.


Assuntos
Genoma , Genômica , Animais , Gossypium/genética , Larva/genética , Filogenia , Spodoptera/genética
17.
Proc Biol Sci ; 289(1988): 20221695, 2022 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-36475436

RESUMO

Insect pests are a major challenge to smallholder crop production in sub-Saharan Africa (SSA), where access to synthetic pesticides, which are linked to environmental and health risks, is often limited. Biological control interventions could offer a sustainable solution, yet an understanding of their effectiveness is lacking. We used a meta-analysis approach to investigate the effectiveness of commonly used biocontrol interventions and botanical pesticides on pest abundance (PA), crop damage (CD), crop yield (Y) and natural enemy abundance (NEA) when compared with controls with no biocontrol and with synthetic pesticides. We also evaluated whether the magnitude of biocontrol effectiveness was affected by type of biocontrol intervention, crop type, pest taxon, farm type and landscape configuration. Overall, from 99 studies on 31 crops, we found that compared to no biocontrol, biocontrol interventions reduced PA by 63%, CD by over 50% and increased Y by over 60%. Compared to synthetic pesticides, biocontrol resulted in comparable PA and Y, while NEA was 43% greater. Our results also highlighted that the potential for biocontrol to be modulated by landscape configuration is a critical knowledge gap in SSA. We show that biocontrol represents an effective tool for smallholder farmers, which can maintain yields without associated negative pesticide effects. Furthermore, the evidence presented here advocates strongly for including biocontrol practices in national and regional agricultural policies.


Assuntos
Produtos Agrícolas , Controle Biológico de Vetores , África Subsaariana
18.
Planta ; 255(2): 36, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35015152

RESUMO

MAIN CONCLUSION: Decreased PG constrains PSI activity due to inhibition of transcript and polypeptide abundance of light-harvesting and reaction center polypeptides generating a reversible, yellow phenotype during cold acclimation of pgp1. Cold acclimation of the Arabidopsis pgp1 mutant at 5 °C resulted in a pale-yellow phenotype with abnormal chloroplast ultrastructure compared to its green phenotype upon growth at 20 °C despite a normal cold-acclimation response at the transcript level. In contrast, wild type maintained its normal green phenotype and chloroplast ultrastructure irrespective of growth temperature. In contrast to cold acclimation of WT, growth of pgp1 at 5 °C limited the accumulation of Lhcbs and Lhcas assessed by immunoblotting. However, a novel 43 kD polypeptide of Lhcb1 as well as a 29 kD polypeptide of Lhcb3 accumulated in the soluble fraction which was absent in the thylakoid membrane fraction of cold-acclimated pgp1 which was not observed in WT. Cold acclimation of pgp1 destabilized the Chl-protein complexes associated with PSI and predisposed energy distribution in favor of PSII rather than PSI compared to the WT. Functionally, in vivo PSI versus PSII photochemistry was inhibited in cold-acclimated pgp1 to a greater extent than in WT relative to controls. Greening of the pale-yellow pgp1 was induced when cold-acclimated pgp1 was shifted from 5 to 20 °C which resulted in a marked decrease in excitation pressure to a level comparable to WT. Concomitantly, Lhcbs and Lhcas accumulated with a simultaneous decrease in the novel 43 and 29kD polypeptides. We conclude that the reduced levels of phosphatidyldiacylglycerol in the pgp1 limit the capacity of the mutant to maintain the structure and function of its photosynthetic apparatus during cold acclimation. Thus, maintenance of normal thylakoid phosphatidyldiacylglycerol levels is essential to stabilize the photosynthetic apparatus during cold acclimation.


Assuntos
Arabidopsis , Fotossíntese , Aclimatação , Arabidopsis/genética , Arabidopsis/metabolismo , Clorofila , Temperatura Baixa , Complexos de Proteínas Captadores de Luz , Peptídeos , Fotoquímica , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo
19.
PLoS Pathog ; 16(6): e1008467, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32569314

RESUMO

Recent advances in next generation sequencing (NGS) (e.g. metagenomic and transcriptomic sequencing) have facilitated the discovery of a large number of new insect viruses, but the characterization of these viruses is still in its infancy. Here, we report the discovery, using RNA-seq, of three new partiti-like viruses from African armyworm, Spodoptera exempta (Lepidoptera: Noctuidae), which are all vertically-transmitted transovarially from mother to offspring with high efficiency. Experimental studies show that the viruses reduce their host's growth rate and reproduction, but enhance their resistance to a nucleopolyhedrovirus (NPV). Via microinjection, these partiti-like viruses were transinfected into a novel host, a newly-invasive crop pest in sub-Saharan Africa (SSA), the Fall armyworm, S. frugiperda. This revealed that in this new host, these viruses appear to be deleterious without any detectable benefit; reducing their new host's reproductive rate and increasing their susceptibility to NPV. Thus, the partiti-like viruses appear to be conditional mutualistic symbionts in their normal host, S. exempta, but parasitic in the novel host, S. frugiperda. Transcriptome analysis of S. exempta and S. frugiperda infected, or not, with the partiti-like viruses indicates that the viruses may regulate pathways related to immunity and reproduction. These findings suggest a possible pest management strategy via the artificial host-shift of novel viruses discovered by NGS.


Assuntos
Nucleopoliedrovírus , Filogenia , Spodoptera/virologia , Animais , Nucleopoliedrovírus/genética , Nucleopoliedrovírus/metabolismo , Spodoptera/genética
20.
J Anim Ecol ; 91(9): 1826-1841, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35678697

RESUMO

Invasive species pose a significant threat to biodiversity and agriculture world-wide. Natural enemies play an important part in controlling pest populations, yet we understand very little about the presence and prevalence of natural enemies during the early invasion stages. Microbial natural enemies of fall armyworm Spodoptera frugiperda are known in its native region, however, they have not yet been identified in Africa where fall armyworm has been an invasive crop pest since 2016. Larval samples were screened from Malawi, Rwanda, Kenya, Zambia, Sudan and Ghana for the presence of four different microbial natural enemies; two nucleopolyhedroviruses, Spodoptera frugiperda NPV (SfMNPV) and Spodoptera exempta NPV (SpexNPV); the fungal pathogen Metarhizium rileyi; and the bacterium Wolbachia. This study aimed to identify which microbial pathogens are present in invasive fall armyworm, and determine the geographical, meteorological and temporal variables that influence prevalence. Within 3 years of arrival, fall armyworm was exposed to all four microbial natural enemies. SfMNPV probably arrived with fall armyworm from the Americas, but this is the first putative evidence of host spillover from Spodoptera exempta (African armyworm) to fall armyworm for the endemic pathogen SpexNPV and for Wolbachia. It is also the first confirmed incidence of M. rileyi infecting fall armyworm in Africa. Natural enemies were localised, with variation being observed both nationally and temporally. The prevalence of SfMNPV (the most common natural enemy) was predominantly explained by variables associated with the weather; declining with increasing rainfall and increasing with temperature. However, virus prevalence also increased as the growing season progressed. The infection of an invasive species with a natural enemy from its native range and novel pathogens specific to its new range has important consequences for understanding the population ecology of invasive species and insect-pathogen interactions. Additionally, while it is widely known that temporal and geographic factors affect insect populations, this study reveals that these are important in understanding the distribution of microbial natural enemies associated with invasive pests during the early stages of invasion, and provide baseline data for future studies.


Assuntos
Nucleopoliedrovírus , Wolbachia , Animais , Espécies Introduzidas , Quênia , Spodoptera
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