scholarly journals Susceptibility monitoring and the molecular characterization of resistance of Spodoptera frugiperda (Lepidoptera: Noctuidae) to lambda-cyhalothrin and chlorpyrifos

2021 ◽  
Author(s):  
Antonio Rogerio Bezerra do Nascimento ◽  
Juliana Gonzales Rodrigues ◽  
Rubens H Kanno ◽  
Fernando S.A. Amaral ◽  
Jose Bruno Malaquias ◽  
...  

Spodoptera frugiperda (J. E. Smith) is a serious and widespread agricultural pest with several records of resistance to different insecticides and Bt proteins, including the neurotoxic insecticides chlorpyrifos (organophosphate) and lambda-cyhalothrin (pyrethroid). In this study, we (i) characterized and monitored the susceptibility of field populations of S. frugiperda to chlorpyrifos (194 populations) and lambda-cyhalothrin (197 populations) collected from major maize-growing regions of Brazil from 2003 to 2016, and (ii) compared gene expression levels of chlorpyrifos- and lambda-cyhalothrin-resistant strains to a susceptible reference strain (Sf-ss) of S. frugiperda. Laboratory-guided assays to monitor larval susceptibility detected average survival ranging from 29.3% to 36.0% to chlorpyrifos, and 23.1% to 68.0% to lambda-cyhalothrin at diagnostic concentration, based on LC99 of the susceptible reference strain of each insecticide. The resistance ratio of the chlorpyrifos-resistant strain (Clo-rr) was 25.4-fold and of the lambda-cyhalothrin-resistant strain (Lam-rr) was 217-fold. Differential gene expression analyses between resistant vs susceptible strains identified 1,098 differentially expressed genes (DEGs) between Clo-rr and Sf-ss, and 303 DEGs between Lam-rr and Sf-ss. Functional analyses of the DEGs revealed the up-regulation of several detoxification enzymes, mainly cytochrome P450 belonging to the CYP3 and CYP6 clans. Genes associated with regulatory processes, such as the forkhead box O (FoxO) were also up-regulated. Our data points that the resistance mechanisms of Clo-rr and Lam-rr strains of S. frugiperda to chlorpyrifos and lambda-cyhalothrin are mainly mediated by enzyme detoxification.

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 875
Author(s):  
Tomasz Bogiel ◽  
Mateusz Rzepka ◽  
Eugenia Gospodarek-Komkowska

Non-fermenting Gram-negative rods are one of the most commonly isolated bacteria from human infections. These microorganisms are typically opportunistic pathogens that pose a serious threat to public health due to possibility of transmission in the human population. Resistance to beta-lactams, due to carbapenemases synthesis, is one of the most important antimicrobial resistance mechanisms amongst them. The aim of this study was to evaluate the usefulness of the Carbapenem Inactivation Method (CIM), and its modifications, for the detection of carbapenemase activity amongst non-fermenting Gram-negative rods. This research involved 81 strains of Gram-negative rods. Of the tested strains, 55 (67.9%) synthesized carbapenemases. For non-fermenting rods, 100% sensitivity and specificity was obtained in the version of the CIM test using imipenem discs and E. coli ATCC 25922 strain. The CIM test allows for differentiation of carbapenems resistance mechanisms resulting from carbapenemase synthesis from other resistance types. It is a reliable diagnostic method for the detection of carbapenemase activity amongst non-fermenting Gram-negative rods. Application of imipenem discs and P. aeruginosa ATCC 27853 reference strain increases CIM results sensitivity, while imipenem discs and E. coli ATCC 25922 strain use maintains full precision of the test for non-fermenting rods.


2013 ◽  
Vol 91 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Sheila S. Teves ◽  
Steven Henikoff

Recent studies in transcriptional regulation using the Drosophila heat shock response system have elucidated many of the dynamic regulatory processes that govern transcriptional activation and repression. The classic view that the control of gene expression occurs at the point of RNA polymerase II (Pol II) recruitment is now giving way to a more complex outlook of gene regulation. Promoter chromatin dynamics coordinate with transcription factor binding to maintain the promoters of active genes accessible. For a large number of genes, the rate-limiting step in Pol II progression occurs during its initial elongation, where Pol II transcribes 30–50 bp and pauses for further signals. These paused genes have unique genic chromatin architecture and dynamics compared with genes where Pol II recruitment is rate limiting for expression. Further elongation of Pol II along the gene causes nucleosome turnover, a continuous process of eviction and replacement, which suggests a potential mechanism for Pol II transit along a nucleosomal template. In this review, we highlight recent insights into transcription regulation of the heat shock response and discuss how the dynamic regulatory processes involved at each transcriptional stage help to generate faithful yet highly responsive gene expression.


2018 ◽  
Vol 115 (48) ◽  
pp. E11321-E11330 ◽  
Author(s):  
Jie Hou ◽  
Xiaowen Shi ◽  
Chen Chen ◽  
Md. Soliman Islam ◽  
Adam F. Johnson ◽  
...  

Changes in dosage of part of the genome (aneuploidy) have long been known to produce much more severe phenotypic consequences than changes in the number of whole genomes (ploidy). To examine the basis of these differences, global gene expression in mature leaf tissue for all five trisomies and in diploids, triploids, and tetraploids of Arabidopsis thaliana was studied. The trisomies displayed a greater spread of expression modulation than the ploidy series. In general, expression of genes on the varied chromosome ranged from compensation to dosage effect, whereas genes from the remainder of the genome ranged from no effect to reduced expression approaching the inverse level of chromosomal imbalance (2/3). Genome-wide DNA methylation was examined in each genotype and found to shift most prominently with trisomy 4 but otherwise exhibited little change, indicating that genetic imbalance is generally mechanistically unrelated to DNA methylation. Independent analysis of gene functional classes demonstrated that ribosomal, proteasomal, and gene body methylated genes were less modulated compared with all classes of genes, whereas transcription factors, signal transduction components, and organelle-targeted protein genes were more tightly inversely affected. Comparing transcription factors and their targets in the trisomies and in expression networks revealed considerable discordance, illustrating that altered regulatory stoichiometry is a major contributor to genetic imbalance. Reanalysis of published data on gene expression in disomic yeast and trisomic mouse cells detected similar stoichiometric effects across broad phylogenetic taxa, and indicated that these effects reflect normal gene regulatory processes.


2019 ◽  
Vol 12 (1) ◽  
pp. 129
Author(s):  
Wagner Justiniano ◽  
Marcos Gino Fernandes

An alternative for the population suppression of Spodoptera frugiperda is the use of toxic baits. The objective of this study was to evaluate the dietary preference and toxic effect of insecticides associated with the attractiveness of S. frugiperda adults as a pest management method. The following attractions were tested: 1) 5% sucrose solution, 2) 10% sugarcane syrup, 3) 10% honey, 4) 5% hydrolyzed protein, 5) Noctovi® 43sb, 6) Noctovi® OVI PLU 1-3, 7) Noctovi® OVI PHE/PAL 50-50 in the study with choice. Attractions: 1) sugarcane syrup 10%, 2) Noctovi® 43sb, 3) Noctovi® 43sb + sugarcane syrup 10%, 4) Noctovi® OVI PLU 1-3 in the study with no chance of choice. For the toxicity study, the food attraction associated with insecticides was used: methomyl 2%, lambda-cyhalothrin 1%, chlorpyriphos 2%, spinosad 1%, chlorantraniliprole 2% and chlorfenapyr 2%. The experimental design was the completely randomized design (CRD) with chance of choice, without chance of choice and toxicity. The following parameters were evaluated: number of insects that fed; time in minutes that remained in the attractive food and mortality. The molasses (10%) and Noctovi® 43sb food attractiveness were significantly more efficient in relation to feeding time and the highest number of landings was observed in the Noctovi® 43sb treatment, both in females and total adults. Methomyl, lambda-cyhalothrin and spinosad insecticides associated with food attractiveness are promising toxic baits for the management of S. frugiperda.


Biotechnology ◽  
2019 ◽  
pp. 1069-1085
Author(s):  
Andrei Lihu ◽  
Ștefan Holban

De novo motif discovery is essential in understanding the cis-regulatory processes that play a role in gene expression. Finding unknown patterns of unknown lengths in massive amounts of data has long been a major challenge in computational biology. Because algorithms for motif prediction have always suffered of low performance issues, there is a constant effort to find better techniques. Evolutionary methods, including swarm intelligence algorithms, have been applied with limited success for motif prediction. However, recently developed methods, such as the Fireworks Algorithm (FWA) which simulates the explosion process of fireworks, may show better prospects. This paper describes a motif finding algorithm based on FWA that maximizes the Kullback-Leibler divergence between candidate solutions and the background noise. Following the terminology of FWA's framework, the candidate motifs are fireworks that generate additional sparks (i.e. derived motifs) in their neighborhood. During the iterations, better sparks can replace the fireworks, as the Fireworks Motif Finder (FW-MF) assumes a one occurrence per sequence mode. The results obtained on a standard benchmark for promoter analysis show that our proof of concept is promising.


2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Nelly F Mostajo ◽  
Marie Lataretu ◽  
Sebastian Krautwurst ◽  
Florian Mock ◽  
Daniel Desirò ◽  
...  

Abstract Although bats are increasingly becoming the focus of scientific studies due to their unique properties, these exceptional animals are still among the least studied mammals. Assembly quality and completeness of bat genomes vary a lot and especially non-coding RNA (ncRNA) annotations are incomplete or simply missing. Accordingly, standard bioinformatics pipelines for gene expression analysis often ignore ncRNAs such as microRNAs or long antisense RNAs. The main cause of this problem is the use of incomplete genome annotations. We present a complete screening for ncRNAs within 16 bat genomes. NcRNAs affect a remarkable variety of vital biological functions, including gene expression regulation, RNA processing, RNA interference and, as recently described, regulatory processes in viral infections. Within all investigated bat assemblies, we annotated 667 ncRNA families including 162 snoRNAs and 193 miRNAs as well as rRNAs, tRNAs, several snRNAs and lncRNAs, and other structural ncRNA elements. We validated our ncRNA candidates by six RNA-Seq data sets and show significant expression patterns that have never been described before in a bat species on such a large scale. Our annotations will be usable as a resource (rna.uni-jena.de/supplements/bats) for deeper studying of bat evolution, ncRNAs repertoire, gene expression and regulation, ecology and important host–virus interactions.


2020 ◽  
Vol 25 (7) ◽  
pp. 1329-1342
Author(s):  
Jia Chen ◽  
Xianyan Ye ◽  
Jing Wang ◽  
Bin Xia ◽  
Tianrong Xin

Diflubenzuron, a benzoylphenylurea insecticide that interferes with chitin biosynthesis, causes arthropods to moult abnormally and die. However, its mechanism of action in Tetranychus cinnabarinus is still unclear. In order to explore the effects of different sublethal concentrations of diflubenzuron on T. cinnabarinus, we conducted a high-throughput RNA-seq technology to identify the variations in transcriptomic profile of T. cinnabarinus larvae. The results revealed that 470 and 49 differentially expressed genes were identified in LC50-and LC70-treated groups, comparing with the control. We also identified and analyzed the detoxification enzymes involved in the transcritome of T. cinnabarinus, including 34 cytochrome P450 genes, 17 glutathione-s-transferase genes (GSTs), 12 acetylcholinesterase genes (AChEs) and 9 ABC transporter genes. In addition, differentially expressed genes analysis showed that the gene expression levels of detoxification enzymes were generally enhanced. At the same time, seven and eleven genes were involved in chitin synthesis and degradation ways, respectively. The expression level of most genes involved in chitin synthesis and degradation pathway were generally up-regulated after exposure to sublethal concentrations of diflubenzuron. Moreover, for transcriptome validation, the mRNA expression results of ten specially expressed genes by quantitative real-time PCR demonstrated that these gene expression trends were consistent with that of the transcriptome data. Together, all these results suggested that sublethal concentrations of diflubenzuron exposure affected gene expression of major detoxification enzymes and chitin metabolism genes in T. cinnabarinus larvae. These findings may be helpful to further understand the possible molecular mechanism of benzoylphenylurea insecticides in T. cinnabarinus, as well as in other spider mites.


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