Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25.923
Filtrar
1.
Parasitol Res ; 121(1): 205-216, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34981215

RESUMO

Schistosomiasis is one of the most important parasitic diseases in tropical and subtropical areas. Its prevalence is associated with the distribution of freshwater snails, which are their intermediate hosts. Thus, control of freshwater snails is the solution to reduce the transmission of this disease. This will be achieved by understanding the relationship between the snails and their habitats including natural enemies and associated aquatic plants as well as the factors affecting their distribution. In this study, Maximum Entropy model (MaxEnt) was used for mapping and predicting the possible geographic distribution of Bulinus truncatus snail (the intermediate host of Schistosoma haematobium), Odonata nymph (predatory aquatic insect), and Ceratophyllum demersum (the associated aquatic plant) in Egypt based on topographic and climatic factors. The models of the investigated species were evaluated using the area under receiver operating characteristic curve. The results showed that the potential risk areas were along the banks of the Nile River and its irrigation canals. In addition, the MaxEnt models revealed some similarities in the distribution pattern of the vector, the predator, and the aquatic plant. It is obvious that the predictive distribution range of B. truncatus was affected by altitude, precipitation seasonality, isothermality, and mean temperature of warmest quarter. The presence of B. truncatus decreases with the increase of altitude and precipitation seasonality values. It could be concluded that the MaxEnt model could help introducing a predictive risk map for Schistosoma haematobium prevalence and performing better management strategies for schistosomiasis.


Assuntos
Bulinus , Odonatos , Animais , Ecossistema , Insetos , Ninfa , Schistosoma haematobium
2.
Braz J Biol ; 84: e253218, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35019097

RESUMO

Indices are used to help on decision-making. This study aims to develop and test an index, which can determine the loss (e.g., herbivorous insects) and solution (e.g., natural enemies) sources. They will be classified according to their importance regarding the ability to damage or to reduce the source of damage to the system when the final production is unknown. Acacia auriculiformis (Fabales: Fabaceae), a non-native pioneer species in Brazil with fast growth and rusticity, is used in restoration programs, and it is adequate to evaluate a new index. The formula was: Percentage of the Importance Indice-Production Unknown (% I.I.-PU) = [(ks1 x c1 x ds1)/Σ (ks1 x c1 x ds1) + (ks2 x c2 x ds2) + (ksn x cn x dsn)] x 100. The loss sources Aethalion reticulatum L., 1767 (Hemiptera: Aethalionidae), Aleyrodidae (Hemiptera), Stereoma anchoralis Lacordaire, 1848 (Coleoptera: Chrysomelidae), and Tettigoniidae, and solution sources Uspachus sp. (Araneae: Salticidae), Salticidae (Araneae), and Pseudomyrmex termitarius (Smith, 1877) (Hymenoptera: Formicidae) showed the highest % I.I.-PU on leaves of A. auriculiformis saplings. The number of Diabrotica speciosa Germar, 1824 (Coleoptera: Chrysomelidae) was reduced per number of Salticidae; that of A. reticulatum that of Uspachus sp.; and that of Cephalocoema sp. (Orthoptera: Proscopiidae) that of P. termitarius on A. auriculiformis saplings. However, the number of Aleyrodidae was increased per number of Cephalotes sp. (Hymenoptera: Formicidae) and that of A. reticulatum that of Brachymyrmex sp. (Hymenoptera: Formicidae) on A. auriculiformis saplings. The A. reticulatum damage was reduced per number of Uspachus sp., but the Aleyrodidae damage was increased per number of Cephalotes sp., totaling 23.81% of increase by insect damages on A. auriculiformis saplings. Here I show and test the % I.I.-PU. It is an new index that can detect the loss or solution sources on a system when production is unknown. It can be applied in some knowledge areas.


Assuntos
Acacia , Formigas , Besouros , Hemípteros , Animais , Insetos
3.
Braz J Biol ; 84: e254095, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35019103

RESUMO

In northern central Chile, ephemeral pools constitute shallow isolated water bodies with a favourable habitat for fauna adapted to seasonal changes. Based on the limited knowledge about the fauna-particularly insects-associated to these ecosystems, the objective of this study was to characterize the richness, composition, structure and similarity of the insect communities associated with ephemeral pools in Huentelauquén (29º S, Coquimbo Region, Chile). By using pitfall traps, 10,762 individuals were captured, represented by 7 orders, 27 families, and 51 species. Coleoptera and Hymenoptera were the best represented orders, with Neuroptera, Orthoptera and Plecoptera being poorly represented groups. The non-parametric estimators evaluated showed wealth values above those observed for all the studied pools, and their accumulation curves suggest the existence of an incomplete species inventory in the studied community. Additionally, the hierarchical and ordering analysis showed groupings of pools located in the northwest and southeast of Huentelauquén. Preliminarily we found a negative correlation between the area of the pools and the richness (species) and abundance of insects. Additional studies (on other arthropod groups and other seasons of the year) could provide a better understanding of the local processes of extinction and colonization of the species inhabiting these fragile coastal environments.


Assuntos
Besouros , Ecossistema , Animais , Biodiversidade , Chile , Humanos , Insetos , Estações do Ano
4.
Chemosphere ; 286(Pt 3): 131785, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34399264

RESUMO

Quantifying methylmercury (MeHg) concentrations and uptake at the base of the food web is useful for assessing mercury exposure risk to higher trophic level organisms. Higher MeHg concentrations near the base of the food web may result in more MeHg exposure and accumulation in higher trophic organisms. Here, we analyze MeHg in caddisflies, mayflies, lake water, and sediment collected from two temperate lakes and one brook in Kejimkujik National Park, Nova Scotia, Canada. Overall, caddisfly larvae MeHg (15.38-276.96 ng/g; n = 29) was not significantly correlated with water chemistry. Whereas mayfly naiads MeHg (14.28-166.82 ng/g; n = 31) was positively correlated with water MeHg (rs = 0.43), negatively correlated with pH (rs = -0.49), and positively correlated with dissolved organic carbon (DOC; rs = 0.48). Of the mercury in insect tissues, the %MeHg ranged from 56 to 75 % in caddisfly larvae and 38-47 % in mayfly naiads. MeHg bioaccumulation factors (BAF) varied greatly (water to tissue BAFs = 0.145 × 106-1.054 × 106; sediment to tissue BAFs = 0.017 × 106-0.541 × 106). This study highlights the importance of quantifying variations in MeHg bioaccumulation and BAFs of common aquatic insect bioindicators at the base of complex food webs.


Assuntos
Ephemeroptera , Mercúrio , Compostos de Metilmercúrio , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Peixes , Cadeia Alimentar , Insetos , Lagos , Mercúrio/análise , Nova Escócia , Água , Poluentes Químicos da Água/análise
5.
Chemosphere ; 287(Pt 1): 131909, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34461331

RESUMO

We present a novel meta-community approach to explore the influence of species traits, such as adult body size, larval feeding type and microhabitat, as well as larval macrohabitat (main river channel vs. floodplain water bodies) on the concentration of total Hg accumulated ([THg]) in assemblages of adult caddisflies. We analyzed [THg] in 157 light-trapped adult caddisflies in a floodplain sector of the French upper Rhône River and used a linear mixed effect model to decipher the role of species traits and habitats in Hg accumulation. Variation of [THg] between species was best explained by the larval feeding type, whereas the contributions of adult size and larval micro and macro-habitat were minor. Results showed that [THg] in species associated with floodplain macrohabitats in the larval stage was lower than in those associated with the main river channel. This difference could depend on complexation of Hg by DOM (in the floodplain) and MES (in the main channel). This research provides a first evidence of the potential of an entire caddisfly assemblage for the assessment of contamination in large alluvial rivers. The implications of the results are discussed in view of the possible role of caddisflies as vectors of Hg to riparian predators.


Assuntos
Mercúrio , Poluentes Químicos da Água , Animais , Ecossistema , Monitoramento Ambiental , Insetos , Mercúrio/análise , Rios , Poluentes Químicos da Água/análise
6.
Gene ; 808: 145986, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34600050

RESUMO

Next-generation sequencing has dramatically fostered insect mitogenomic research in recent years. However, studies on the insect mitochondrial genome (mitogenome) assembly mainly rely on the sequencing data from total DNA, which is not cost-effective as a huge data from nuclear DNA are wasted. Besides, many mitogenomic studies require genomic information from individual organisms, whereas the DNA yield from small individual insects is too low to meet the sequencing requirements. Here, we describe a strategy for a high enrichment of insect mitochondrial DNA (mtDNA) using rolling circle amplification (RCA) technique. This strategy consists of standard DNA extraction, RCA enrichment, next-generation sequencing and mitogenome assembly. We have evaluated the performance of this strategy on nine insect species representing eight families of insecta, three other invertebrates, and even two vertebrate specimens. Results show that our strategy is especially suitable for insects, which allows almost all tested insect mtDNA contents to reach 80% and above. A further examination of enrichment efficiency of our strategy among different taxa shows that it is also applicable to other invertebrates and even some vertebrates such as Rhacophorus and ptyas species, although its enrichment efficiency in these groups is lower than that of insects. After treatment with our strategy, small flux sequencing data can realize the assembly of mitogenome with deep coverage, providing a solid base for subsequent mitogenome-based studies.


Assuntos
DNA Mitocondrial/genética , DNA Mitocondrial/isolamento & purificação , Insetos/genética , Animais , Genoma de Inseto/genética , Genoma Mitocondrial/genética , Genômica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mitocôndrias/genética , Filogenia , Análise de Sequência de DNA/métodos
7.
Sci Total Environ ; 804: 150022, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34517322

RESUMO

As complex mosaics of lotic, lentic, and terrestrial habitats, intermittent rivers and ephemeral streams (IRES) support high biodiversity. Despite their ecological importance, IRES are poorly represented in routine monitoring programs, but recent recognition of their considerable-and increasing-spatiotemporal extent is motivating efforts to better represent IRES in ecological status assessments. We examine response patterns of aquatic macroinvertebrate communities and taxa to flow intermittence (FI) across three European climatic regions. We used self-organizing map (SOM) to ordinate and classify sampling sites based on community structure in regions with continental, Mediterranean and oceanic climates. The SOM passively introduced FI, quantified as the mean annual % flow, and visualized its variability across classified communities, revealing a clear association between community structure and FI in all regions. Indicator species analysis identified taxa indicative of low, intermediate and high FI. In the continental region, the amphipod Niphargus was indicative of high FI and was associated with groundwater-fed IRES, whereas indicators of Mediterranean IRES comprised Odonata, Coleoptera and Heteroptera taxa, which favor lentic conditions. In the oceanic region, taxa indicative of relatively high FI included leuctrid stoneflies and a limnephilid caddisfly, likely reflecting the colonization of IRES by aerial adults from nearby perennial reaches. The Diptera families Chironomidae and Simuliidae showed contrasting FI preferences among regions, reflecting environmental heterogeneity between regions and the coarse taxonomic resolution to which these organisms were identified. These region-specific community and taxon responses of aquatic biota to FI highlight the need to adapt standard biotic indices to enable effective ecological status assessments in IRES.


Assuntos
Biomarcadores Ambientais , Rios , Animais , Ecossistema , Monitoramento Ambiental , Humanos , Insetos , Invertebrados
8.
Food Chem ; 373(Pt A): 131407, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-34715633

RESUMO

Chitosan is a deacetylated form of chitin and increasingly important amino-polysaccharide used in many various sectors including agriculture, food, and biomedicine. However, chitosan from marine sources has several adverse effects, including allergenic components harmful to human health. Furthermore, marine resources are seasonal, and availability is limited due to dependency on environmental conditions and climate change. In addition, shell infection in crustaceans and environmental contamination make the harvesting of chitin and chitosan problematic. In recent years, chitosan from terrestrial insects has attracted considerable interest. The discoveries show insect chitosan is more advantageous compared to crustacean chitosan. In addition, we were unable to find any literature about the adverse effects of insect chitosan thus far. This review aims to reveal information regarding crustacean and terrestrial insect chitosan and recent advances in chitosan sources. Applications from specific insect orders and perspectives for further study will also be highlighted, including medical and sensing applications.


Assuntos
Quitosana , Animais , Quitina , Crustáceos , Humanos , Insetos , Alimentos Marinhos
9.
Sci Total Environ ; 806(Pt 3): 151318, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34743879

RESUMO

The United States has thousands of invasive species, representing a sizable, but unknown burden to the national economy. Given the potential economic repercussions of invasive species, quantifying these costs is of paramount importance both for national economies and invasion management. Here, we used a novel global database of invasion costs (InvaCost) to quantify the overall costs of invasive species in the United States across spatiotemporal, taxonomic, and socioeconomic scales. From 1960 to 2020, reported invasion costs totaled $4.52 trillion (USD 2017). Considering only observed, highly reliable costs, this total cost reached $1.22 trillion with an average annual cost of $19.94 billion/year. These costs increased from $2.00 billion annually between 1960 and 1969 to $21.08 billion annually between 2010 and 2020. Most costs (73%) were related to resource damages and losses ($896.22 billion), as opposed to management expenditures ($46.54 billion). Moreover, the majority of costs were reported from invaders from terrestrial habitats ($643.51 billion, 53%) and agriculture was the most impacted sector ($509.55 billion). From a taxonomic perspective, mammals ($234.71 billion) and insects ($126.42 billion) were the taxonomic groups responsible for the greatest costs. Considering the apparent rising costs of invasions, coupled with increasing numbers of invasive species and the current lack of cost information for most known invaders, our findings provide critical information for policymakers and managers.


Assuntos
Ecossistema , Espécies Introduzidas , Agricultura , Animais , Efeitos Psicossociais da Doença , Custos de Cuidados de Saúde , Insetos , Estados Unidos
10.
Micron ; 152: 103176, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34763214

RESUMO

The fine structure of the larval eyes of the hangingfly Terrobittacus implicatus (Huang & Hua) was investigated using scanning and transmission electron microscopy. The results show that the larval eyes of T. implicatus each consist of seven spaced ommatidia. Each ommatidium is composed of a corneal lens with about 45 lamellae, a tetrapartite eucone type of crystalline cone, eight retinula cells, two primary pigment cells, and an undetermined number of secondary pigment cells. The rhabdomeres of eight retinula cells effectively fuse into a centrally-fused, tiered funnel-shaped rhabdom extending from the base of the crystalline cone deeply into the ommatidium. In light of different positions in the ommatidium, the retinula cells can be divided into four distal and four proximal retinula cells. Pigment cells envelop the entire ommatidium. Electron-lucent vesicles are abundant throughout the cytoplasm of the eight retinula cells. The larval ommatidia of T. implicatus are similar to those of the Panorpidae, except for the distal retinula cells that also participate in the formation of the proximal rhabdom. In this case, the larval eyes of T. implicatus may lie in the transitional stage during the larval eye evolution of insects from ommatidia to stemmata.


Assuntos
Córnea , Insetos , Animais , Citoplasma , Olho , Larva , Microscopia Eletrônica de Transmissão
11.
Phytochemistry ; 193: 113008, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34768189

RESUMO

For more than 350 million years, there have been ongoing dynamic interactions between plants and insects. In several cases, insects cause-specific feeding damage with ensuing herbivore-associated molecular patterns that invoke characteristic defense responses. During feeding on plant tissue, insects release oral secretions (OSs) containing a repertoire of molecules affecting plant defense (effectors). Some of these OS components might elicit a defense response to combat insect attacks (elicitors), while some might curb the plant defenses (suppressors). Few reports suggest that the synthesis and function of OS components might depend on the host plant and associated microorganisms. We review these intricate plant-insect interactions, during which there is a continuous exchange of molecules between plants and feeding insects along with the associated microorganisms. We further provide a list of commonly identified inducible plant produced defensive molecules released upon insect attack as well as in response to OS treatments of the plants. Thus, we describe how plants specialized and defense-related metabolism is modulated at innumerable phases by OS during plant-insect interactions. A molecular understanding of these complex interactions will provide a means to design eco-friendly crop protection strategies.


Assuntos
Herbivoria , Plantas , Animais , Insetos
12.
Plant Sci ; 314: 111114, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34895543

RESUMO

Reactive oxygen species (ROS) are considered the first signaling molecules involved in gall development, linked to the establishment of cyto-histological gradients leading to gall tissue redifferentiation. ROS overproduction induces the failure of gall establishment or its premature senescence. Galls could therefore have efficient mechanisms of ROS dissipation and maintenance of homeostasis, such as polyphenol synthesis. The co-occurrence of ROS and polyphenols in the Espinosa nothofagi galls induced on Nothofagus obliqua buds was explored and was related to the antioxidant capacity of the inner (IC) and outer (OC) gall compartments. We hypothesize that: (i) ROS are produced and accumulated in both tissue compartments of E. nothofagi galls in co-occurrence with polyphenolic, flavonols, and lignin, conferring high antioxidant activity to inner and outer gall tissue compartment; (ii) antioxidant activity is higher in IC related to a higher polyphenol concentration in this compartment. The results show that ROS and polyphenols, mainly flavonols, are produced and accumulated in IC and OC, while lignin accumulated mainly in the IC. In both gall compartments, polyphenols mediate ROS elimination, confirmed by histochemical and spectrophotometry techniques. The IC extract has the highest antioxidant capacity, probably due to lignin deposition and a higher polyphenol concentration in this compartment.


Assuntos
Antioxidantes/metabolismo , Fagales/metabolismo , Fagales/parasitologia , Interações Hospedeiro-Parasita/efeitos dos fármacos , Insetos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenóis/metabolismo , Tumores de Planta/parasitologia , Animais , Chile , Transdução de Sinais/efeitos dos fármacos
13.
J Virol Methods ; 299: 114341, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34699776

RESUMO

The COVID-19 pandemic has demanded a range of biotechnological products for detection of SARS-CoV-2 variants and evaluation of human seroconversion after infection or vaccination. In this work, we describe an easy pipeline for expression of SARS-CoV-2 nucleocapsid (N) protein in insect cells followed by its purification via affinity chromatography. The N gene was cloned into the genome of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) via transposition and the resulting recombinant baculovirus was used for infection of lepidopteran Sf9 cells adapted to high-density suspension. Using Tris-HCl pH 8.0 buffer as mobile phase and eluting bound proteins with 175 mM imidazole as part of a three-step gradient, an average of 1 mg N protein could be purified from each 50 mg of total protein from clarified supernatant. Such protein amount allows the manufacturing of serological tests and the development of basic studies on cellular responses to SARS-CoV-2.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Humanos , Insetos , Nucleocapsídeo , Proteínas do Nucleocapsídeo/genética , Pandemias
14.
Sci Total Environ ; 804: 150162, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798730

RESUMO

Repurposing of brownfield sites is often promoted, because it is perceived that protecting the "green belt" limits damage to biodiversity; yet brownfield sites provide scarce habitats with limited disturbance, so conversely are also perceived to be ecologically valuable. Combining data from three national-scale UK biological monitoring schemes with location data on historical landfill sites, we show that species richness is positively associated with both the presence and increasing area of ex-landfill sites for birds, plants and several insect taxa. Assemblage rarity of birds is also positively associated with presence of ex-landfill sites. Species richness associated with ex-landfill sites declined over time for birds and insects but increased over time for plants. These findings suggest that development of brownfield sites may have unintended negative consequences for biodiversity, and imply that to minimise loss of biodiversity, brownfield site repurposing could be targeted towards smaller sites, or sites in areas with a high density of other brownfield sites.


Assuntos
Biodiversidade , Ecossistema , Animais , Aves , Conservação dos Recursos Naturais , Insetos , Plantas
15.
Methods Mol Biol ; 2360: 1-8, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34495502

RESUMO

MicroRNAs (miRNAs) are important regulatory noncoding RNAs (ncRNAs) at the posttranscriptional level of gene expression. Linear long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) can function as competing endogenous RNAs (ceRNAs) of miRNAs and regulate the expression of protein-coding genes. This chapter presents a procedure for the bioinformatic analysis of these three ncRNAs that are differentially expressed during insect development. In the first step, lncRNAs and circRNAs are identified based on RNA-sequencing data. In the second step, miRNAs are identified based on small RNA-sequencing data and combined with the two ncRNAs from the previous step for functional characterization.


Assuntos
RNA Longo não Codificante/genética , Animais , Genoma , Insetos/genética , MicroRNAs/genética , RNA Circular , RNA não Traduzido/genética
16.
Methods Mol Biol ; 2360: 85-90, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34495509

RESUMO

RNA interference (RNAi) comprises a natural mechanism of gene regulation and antiviral defense system in eukaryotic cells, and results in sequence-specific degradation of RNAs. Recent scientific studies demonstrate the feasibility of use RNAi-based strategies to control pest and pathogens in plants. A key step in developing RNAi-based products is a reliable method to appropriated screening of selected dsRNAs.Herein presented are a bioassay for screening dsRNAs to control the Asian citrus psyllid (ACP), Diaphorina citri, vector of citrus Huanglongbing (HLB) and other hemipterans. The RNAi feeding bioassay, called in plant system (iPS), uses vegetative new growth citrus flush to deliver double-strand RNA (dsRNA ) to ACP during natural feeding .


Assuntos
Hemípteros , Animais , Bioensaio , Citrus , Hemípteros/genética , Insetos , Doenças das Plantas/genética , Doenças das Plantas/prevenção & controle , Interferência de RNA , RNA de Cadeia Dupla/genética
17.
New Phytol ; 233(1): 132-144, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34363707

RESUMO

Florivory is an ancient interaction which has rarely been quantified due to a lack of standardized protocols, thus impairing biogeographical and phylogenetic comparisons. We created a global, continuously updated, open-access database comprising 180 species and 64 families to compare floral damage between tropical and temperate plants, to examine the effects of plant traits on floral damage, and to explore the eco-evolutionary dynamics of flower-florivore interactions. Flower damage is widespread across angiosperms, but was two-fold higher in tropical vs temperate species, suggesting stronger fitness impacts in the tropics. Flowers were mostly damaged by chewers, but neither flower color nor symmetry explained differences in florivory. Herbivory and florivory levels were positively correlated within species, even though the richness of the florivore community does not affect florivory levels. We show that florivory impacts plant fitness via multiple pathways and that ignoring this interaction makes it more difficult to obtain a broad understanding of the ecology and evolution of angiosperms. Finally, we propose a standardized protocol for florivory measurements, and identify key research avenues that will help fill persistent knowledge gaps. Florivory is expected to be a central research topic in an epoch characterized by widespread decreases in insect populations that comprise both pollinators and florivores.


Assuntos
Flores , Magnoliopsida , Animais , Herbivoria , Insetos , Filogenia , Polinização
18.
Methods Mol Biol ; 2360: 175-185, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34495515

RESUMO

In the past two decades, studies investigating RNAi-based pest control have continued as a major focus of research. In this chapter, I describe the crucial procedure of examining the suitability of attractive target genes in insects for RNAi-based pest control, including preliminarily examining the suitability of the candidate genes by gene expression analysis, encapsulating dsRNA using nanoparticles to avoid degradation caused by insect digestive systems, and introducing exogenous dsRNAs into pests through micro-injection to rapidly and effectively examine the suitability of dsRNA in vivo in insects.


Assuntos
Controle de Pragas , Interferência de RNA , Animais , Insetos/genética , RNA de Cadeia Dupla/genética
19.
Methods Mol Biol ; 2360: 217-233, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34495518

RESUMO

Cultivated cotton (Gossypium hirsutum) is heavily attacked by various species of insects worldwide and breeding of new varieties resistant to pests is still a hard battle to win. RNAi technology is an important reverse genetics tool to induce gene silencing in eukaryotic organisms and produce phenotypic modifications. In cotton, RNAi was applied to investigate gene function and enhance resistance to insects and pathogens. Different methods and techniques can be used to synthetize double stranded RNA (dsRNA) into plant cells. The Agrobacterium-mediated transformation is a common method to introduce RNAi binary plasmids into cotton genome and obtain stable transgenics plants. This methodology includes the coculture of cotton tissues with Agrobacterium cultures, selection of transgenic cells and induction of somatic embryogenesis to finally obtain transgenic plants after a relatively long period of time. The transient synthesis of dsRNA mediated by virus-induced gene silencing (VIGS) in cotton is an alternative to anticipate the silencing effect of a specific RNA sequence, prior to the development of a stable transgenic plant. VIGS vectors are incorporated into the plant by agroinfiltration technique. During VIGS replication inside plant cells, synthetized dsRNA allows the study on specific heterologous gene expression including the phenotypic effect on herbivorous target pests, thus facilitating a rapid evaluation of dsRNA expressed in cotton plants against individual insect target genes. Here we describe the complementation of these two techniques to evaluate RNAi-based cotton plant protection against insect pests.


Assuntos
Gossypium , Agrobacterium/genética , Animais , Gossypium/genética , Insetos , Melhoramento Vegetal , Plantas Geneticamente Modificadas/genética , Interferência de RNA , RNA de Cadeia Dupla/genética
20.
Methods Mol Biol ; 2360: 235-252, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34495519

RESUMO

Expressing insecticidal double-stranded RNA (dsRNA) molecules in plant plastids is a novel approach for in planta production of dsRNA that has enormous potential for developing improved plant-mediated RNA interference (RNAi) strategies for insect pest control. In this chapter, we describe the design of a transformation vector containing an expression cassette which can be used to stably transform plastids of tomato plants for production and accumulation of dsRNA . Such dsRNA can trigger the mechanisms of RNAi in pest insects and selectively suppress the expression of target genes, resulting in lethality. We also describe a protocol for detection of full-length dsRNA molecules in plastids using an RT-PCR-based method.


Assuntos
Biolística , Lycopersicon esculentum , Animais , Insetos/genética , Lycopersicon esculentum/genética , Interferência de RNA , RNA de Cadeia Dupla/genética , RNA de Plantas/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...