scholarly journals Genome-wide survey of cytochrome P450 genes in the salmon louse Lepeophtheirus salmonis (Krøyer, 1837)

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Joseph L. Humble ◽  
Greta Carmona-Antoñanzas ◽  
Carol M. McNair ◽  
David R. Nelson ◽  
David I. Bassett ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Molecular Mechanisms ◽  
Constitutive Expression ◽  
Transcript Abundance ◽  
Fruit Fly ◽  
Environmental Chemicals ◽  
Veterinary Drug ◽  
Economic Damage ◽  
Lepeophtheirus Salmonis ◽  
Salmon Louse

Abstract Background The salmon louse (Lepeophtheirus salmonis) infests farmed and wild salmonid fishes, causing considerable economic damage to the salmon farming industry. Infestations of farmed salmon are controlled using a combination of non-medicinal approaches and veterinary drug treatments. While L. salmonis has developed resistance to most available salmon delousing agents, relatively little is known about the molecular mechanisms involved. Members of the cytochrome P450 (CYP) superfamily are typically monooxygenases, some of which are involved in the biosynthesis and metabolism of endogenous compounds, while others have central roles in the detoxification of xenobiotics. In terrestrial arthropods, insecticide resistance can be based on the enhanced expression of CYPs. The reported research aimed to characterise the CYP superfamily in L. salmonis and assess its potential roles in drug resistance. Methods Lepeophtheirus salmonis CYPs were identified by homology searches of the genome and transcriptome of the parasite. CYP transcript abundance in drug susceptible and multi-resistant L. salmonis was assessed by quantitative reverse transcription PCR, taking into account both constitutive expression and expression in parasites exposed to sublethal levels of salmon delousing agents, ecdysteroids and environmental chemicals. Results The above strategy led to the identification of 25 CYP genes/pseudogenes in L. salmonis, making its CYP superfamily the most compact characterised for any arthropod to date. Lepeophtheirus salmonis possesses homologues of a number of arthropod CYP genes with roles in ecdysteroid metabolism, such as the fruit fly genes disembodied, shadow, shade, spook and Cyp18a1. CYP transcript expression did not differ between one drug susceptible and one multi-resistant strain of L. salmonis. Exposure of L. salmonis to emamectin benzoate or deltamethrin caused the transcriptional upregulation of certain CYPs. In contrast, neither ecdysteroid nor benzo[a]pyrene exposure affected CYP transcription significantly. Conclusions The parasite L. salmonis is demonstrated to possess the most compact CYP superfamily characterised for any arthropod to date. The complement of CYP genes in L. salmonis includes conserved CYP genes involved in ecdysteroid biosynthesis and metabolism, as well as drug-inducible CYP genes. The present study does not provide evidence for a role of CYP genes in the decreased susceptibility of the multiresistant parasite strain studied.

scholarly journals The FTZ-F1 gene encodes two functionally distinct nuclear receptor isoforms in the ectoparasitic copepod salmon louse (Lepeophtheirus salmonis)

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251575
Author(s):  
Joakim Brunet ◽  
Christiane Eichner ◽  
Rune Male
Keyword(s):  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Lepeophtheirus Salmonis ◽  
Adult Males ◽  
Molting Cycle ◽  
Salmon Louse ◽  
Receptor Isoforms ◽  
Cyclical Pattern ◽  
Alternative Transcription ◽  
Vitellogenic Stage

The salmon louse, Lepeophtheirus salmonis, is an ectoparasitic crustacean that annually inflicts substantial losses to the aquaculture industry in the northern hemisphere and poses a threat to the wild populations of salmonids. The salmon louse life cycle consists of eight developmental stages each separated by a molt. Fushi Tarazu Factor-1 (FTZ-F1) is an ecdysteroid-regulated gene that encodes a member of the NR5A family of nuclear receptors that is shown to play a crucial regulatory role in molting in insects and nematodes. Characterization of an FTZ-F1 orthologue in the salmon louse gave two isoforms named αFTZ-F1 and βFTZ-F1, which are identical except for the presence of a unique N-terminal domain (A/B domain). A comparison suggest conservation of the FTZ-F1 gene structure among ecdysozoans, with the exception of nematodes, to produce isoforms with unique N-terminal domains through alternative transcription start and splicing. The two isoforms of the salmon louse FTZ-F1 were expressed in different amounts in the same tissues and showed a distinct cyclical expression pattern through the molting cycle with βFTZ-F1 being the highest expressed isoform. While RNA interference knockdown of βFTZ-F1 in nauplius larvae and in pre-adult males lead to molting arrest, knockdown of βFTZ-F1 in pre-adult II female lice caused disruption of oocyte maturation at the vitellogenic stage. No apparent phenotype could be observed in αFTZ-F1 knockdown larvae, or in their development to adults, and no genes were found to be differentially expressed in the nauplii larvae following αFTZ-F1 knockdown. βFTZ-F1 knockdown in nauplii larvae caused both down and upregulation of genes associated with proteolysis and chitin binding and affected a large number of genes which are in normal salmon louse development expressed in a cyclical pattern. This is the first description of FTZ-F1 gene function in copepod crustaceans and provides a foundation to expand the understanding of the molecular mechanisms of molting in the salmon louse and other copepods.

scholarly journals Comparative Transcriptomic Analysis of Riptortus pedestris (Hemiptera: Alydidae) to Characterize Wing Formation across All Developmental Stages

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 226
Author(s):  
Siying Fu ◽  
Yujie Duan ◽  
Siqi Wang ◽  
Yipeng Ren ◽  
Wenjun Bu
Keyword(s):  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Average Length ◽  
Transcriptome Assembly ◽  
Expression Profiles ◽  
Economic Losses ◽  
Future Research ◽  
Economic Damage ◽  
Wing Formation ◽  
Riptortus Pedestris

Riptortus pedestris (Hemiptera: Alydidae) is a major agricultural pest in East Asia that causes considerable economic losses to the soybean crop each year. However, the molecular mechanisms governing the growth and development of R. pedestris have not been fully elucidated. In this study, the Illumina HiSeq6000 platform was employed to perform de novo transcriptome assembly and determine the gene expression profiles of this species across all developmental stages, including eggs, first-, second-, third-, fourth-, and fifth-instar nymphs, and adults. In this study, a total of 60,058 unigenes were assembled from numerous raw reads, exhibiting an N50 length of 2126 bp and an average length of 1199 bp, and the unigenes were annotated and classified with various databases, such as the Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Groups (COG), and Gene Ontology (GO). Furthermore, various numbers of differentially expressed genes (DEGs) were calculated through pairwise comparisons of all life stages, and some of these DEGs were associated with immunity, metabolism, and development by GO and KEGG enrichment. In addition, 35,158 simple sequence repeats (SSRs) and 715,604 potential single nucleotide polymorphisms (SNPs) were identified from the seven transcriptome libraries of R. pedestris. Finally, we identified and summarized ten wing formation-related signaling pathways, and the molecular properties and expression levels of five wing development-related genes were analyzed using quantitative real-time PCR for all developmental stages of R. pedestris. Taken together, the results of this study may establish a foundation for future research investigating developmental processes and wing formation in hemimetabolous insects and may provide valuable data for pest control efforts attempting to reduce the economic damage caused by this pest.

Stimulation of the acute-phase response in simian virus 40-hepatocyte cell lines

1989 ◽  
Vol 9 (7) ◽  
pp. 2779-2786
Author(s):  
W S Liao ◽  
K T Ma ◽  
C D Woodworth ◽  
L Mengel ◽  
H C Isom
Keyword(s):  
Cell Lines ◽  
Acute Phase ◽  
Molecular Mechanisms ◽  
Constitutive Expression ◽  
Simian Virus 40 ◽  
Normal Liver ◽  
Simian Virus ◽  
Cdna Clones ◽  
Dependent Manner ◽  
Amyloid A

Seven simian virus 40 (SV40)-hepatocyte cell lines were characterized with respect to the ability to express eight liver acute-phase genes. cDNA clones corresponding to albumin, serum amyloid A, alpha 1-acid glycoprotein, haptoglobin, alpha-, beta-, and gamma-fibrinogen, and alpha 1-major-acute-phase protein mRNAs were used in Northern (RNA) or slot blot analyses. In the noninduced state, six of the seven cell lines showed significant (i.e., liverlike) levels of constitutive expression of all genes examined except that expression of haptoglobin mRNA was considerable lower than in the normal liver. To examine whether these immortalized liver cells can respond appropriately to inflammatory mediators, cells were treated with conditioned medium from activated human monocytes or mixed lymphocyte cultures. Results showed that these SV40-hepatocyte cell lines responded to the conditioned media in culture by down-regulating albumin gene expression and up-regulating other acute-phase genes in a time- and dose-dependent manner. These results indicate that the SV40-hepatocytes retained not only the ability to express a number of acute-phase genes but also the ability to respond to external stimuli. The usefulness of these cell lines for analysis of the molecular mechanisms involved in the regulation of these acute-phase genes is discussed.

scholarly journals Detoxification and Immune Transcriptomic Response of the Gill Tissue of Bay Scallop (Argopecten irradians) Following Exposure to the Algicide Palmitoleic Acid

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 139 ◽  
Author(s):  
Cheng Chi ◽  
Sib Giri ◽  
Jin Jun ◽  
Hyoun Kim ◽  
Sang Kim ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cytochrome P450 ◽  
Palmitoleic Acid ◽  
Molecular Mechanisms ◽  
Functional Enrichment ◽  
Alexandrium Tamarense ◽  
Read Length ◽  
Related Factor ◽  
Transcriptomic Response ◽  
Bay Scallop

Palmitoleic acid (PA) is an effective algicide against Alexandrium tamarense. However, the toxicological mechanism of PA exposure is unclear. The transcript abundance and differentially expressed genes (DEGs) in gills of bay scallop were investigated following 80 mg/L PA exposure up to 48 h using the Illumina HiSeq 4000 deep-sequencing platform with the recommended read length of 100 bp. De novo assembly of paired-end reads yielded 62,099 unigenes; 5414 genes were identified as being significantly increased, and 4452 were decreased. Based on gene ontology classification and enrichment analysis, the ‘cellular process’, ‘metabolic process’, ‘response to stimulus’, and ‘catalytic process’ with particularly high functional enrichment were revealed. The DEGs, which are related to detoxification and immune responses, revealed that acid phosphatase, fibrinogen C domain-containing protein, cyclic AMP-responsive element-binding protein, glutathione reductase, ATP-binding cassette, nuclear factor erythroid 2-related factor, NADPH2:quinone reductase, and cytochrome P450 4F22, 4B1, and 2C8-related gene expression decreased. In contrast, some genes related to glutathione S-transferase, C-type lectin, superoxide dismutase, toll-like receptors, and cytochrome P450 2C14, 2U1, 3A24 and 4A2 increased. The results of current research will be a valuable resource for the investigation of gene expression stimulated by PA, and will help understanding of the molecular mechanisms underlying the scallops’ response to PA exposure.

Probing Enhanced Cytochrome P450 2B1/2 Activity in Rat Hepatocyte Spheroids through Confocal Laser Scanning Microscopy

2001 ◽  
Vol 10 (3) ◽  
pp. 329-342 ◽  
Author(s):  
Emmanouhl S. Tzanakakis ◽  
Chang-Chun Hsiao ◽  
Taku Matsushita ◽  
Rory P. Remmel ◽  
Wei-Shou Hu
Keyword(s):  
Cytochrome P450 ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Constitutive Expression ◽  
Rat Hepatocytes ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser

Cytochrome P450 (CYP450) enzymes are essential for xenobiotic metabolism. Although CYP450s are found in many tissues, CYP2B1/2 are primarily expressed in the rat liver. The constitutive expression in vivo of CYP2B1/2 is low but it is induced in the presence of various drugs such as phenobarbital (PB). In this study, CYP2B1/2 activity in cultured hepatocytes was assessed in situ with the introduction of a fluorogenic sub-strate, pentoxyresorufin. The product of 7-pentoxyresorufin-O-dealkylation (PROD), which is catalyzed specifically by CYP2B1/2, was detected using confocal laser scanning microscopy (CLSM). Primary hepatocytes cultured as monolayers on collagen-coated surfaces exhibited background PROD activity and minimal PB inducibility after 4 days in culture. In contrast, rat hepatocytes organized in compacted aggregates, or spheroids, exhibited higher levels of PROD activity and retained their ability for PB induction. The results from the CLSM analysis were verified by RT-PCR and Western immunoblotting analysis. Furthermore, CLSM in conjunction with image processing techniques and three-dimensional reconstruction revealed the localization of enhanced PROD activity in the center of spheroids. The results support the use of CLSM as a powerful tool for investigating CYP2B1/2 activity in cultured rat hepatocytes.

Diel vertical distribution of early marine phase juvenile pink salmon (Oncorhynchus gorbuscha) and behaviour when exposed to salmon louse (Lepeophtheirus salmonis)

2011 ◽  
Vol 89 (9) ◽  
pp. 796-807 ◽  
Author(s):  
S. Tang ◽  
A.G. Lewis ◽  
M. Sackville ◽  
L. Nendick ◽  
C. DiBacco ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Pink Salmon ◽  
Distribution Patterns ◽  
Oncorhynchus Gorbuscha ◽  
Lepeophtheirus Salmonis ◽  
Night Time ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Louse ◽  
Seawater Acclimation

We observed diel vertical migration patterns in juvenile pink salmon ( Oncorhynchus gorbuscha (Walbaum, 1792)) and tested the hypothesis that fish behaviour is altered by exposure to sea lice copepodids. Experiments involved replicated field deployments of a large (9 m) plankton column, which provided a vertical distribution enclosure under natural light and salinity conditions. Diel vertical distributions of juvenile pink salmon were observed during the first 3 weeks of seawater acclimation in both the presence and the absence of the ectoparasitic salmon louse ( Lepeophtheirus salmonis (Krøyer, 1838)). Immediately upon entering seawater, juvenile pink salmon preferred the top 1 m of the water column, but they moved significantly deeper down the vertical water column as seawater acclimation time increased. A significant diel migration pattern was observed, which involved a preference for the surface at night-time, compared with daytime. When fish in the column were exposed to L. salmonis copepodids for 3 h, 43%–62% of fish became infected, fish expanded their vertical distribution range, and significant changes in vertical distribution patterns were observed.

scholarly journals Transcriptome characterization analysis and molecular profiles of obligatory diapause induction of the Chinese citrus fruit fly,Bactrocera minax(Diptera: Tephritidae)

2019 ◽  
Author(s):  
Zhixiong Zhou ◽  
Xiaolin Dong ◽  
Chuanren Li
Keyword(s):  
Signaling Pathway ◽  
Molecular Mechanisms ◽  
Expression Patterns ◽  
Citrus Fruit ◽  
Pupal Stage ◽  
Fruit Fly ◽  
Diapause Induction ◽  
Regulation Mechanism ◽  
Pupal Diapause ◽  
Specific Stage

AbstractThe Chinese citrus fruit fly,Bactrocera minax, is a devastating citrus pest in China, Bhutan and India. It will enter obligatory pupal diapause in each generation at specific stage, while little is known about the course and the molecular mechanisms of diapause induction. To gain insight into possible mechanisms of obligatory pupal diapause induction, high-throughput RNA-seq data were generated from second-instar larvae (2L), third-instar larvae (3L) and pupal (P, one week after pupating). A total of 116,402 unigenes were assembled and researched against public databases, and 54,781 unigenes matched to proteins in the NCBI database using the BLAST search. Three pairwise comparisons were performed, and significantly differentially regulated transcripts were identified. Several differentially expressed genes (DEGs) expression patterns revealed that those highly or lowly expressed genes in pupal stage were predicted to be involved in diapause induction. Moreover, GO function and KEGG pathway analysis were performed on all DEGs and showed that 20-hydroxyecdysone (20E) biosynthesis, insulin signaling pathway, FoxO signaling pathway, cell cycle and metabolism pathway may be related to the obligatory diapause of the Chinese citrus fruit fly. This study provides valuable information about the Chinese citrus fruit fly transcriptome for future gene function research, and contributes to the in-depth elucidation of the molecular regulation mechanism of insect obligatory diapause induction.

scholarly journals The Making of Long-Lasting Memories: A Fruit Fly Perspective

2021 ◽  
Vol 15 ◽  
Author(s):  
Camilla Roselli ◽  
Mani Ramaswami ◽  
Tamara Boto ◽  
Isaac Cervantes-Sandoval
Keyword(s):  
Learning And Memory ◽  
Neural Activity ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Fruit Fly ◽  
Memory Formation ◽  
Synaptic Activity ◽  
Model Organisms ◽  
Transient Wave ◽  
Control Of Gene Expression

Understanding the nature of the molecular mechanisms underlying memory formation, consolidation, and forgetting are some of the fascinating questions in modern neuroscience. The encoding, stabilization and elimination of memories, rely on the structural reorganization of synapses. These changes will enable the facilitation or depression of neural activity in response to the acquisition of new information. In other words, these changes affect the weight of specific nodes within a neural network. We know that these plastic reorganizations require de novo protein synthesis in the context of Long-term memory (LTM). This process depends on neural activity triggered by the learned experience. The use of model organisms like Drosophila melanogaster has been proven essential for advancing our knowledge in the field of neuroscience. Flies offer an optimal combination of a more straightforward nervous system, composed of a limited number of cells, and while still displaying complex behaviors. Studies in Drosophila neuroscience, which expanded over several decades, have been critical for understanding the cellular and molecular mechanisms leading to the synaptic and behavioral plasticity occurring in the context of learning and memory. This is possible thanks to sophisticated technical approaches that enable precise control of gene expression in the fruit fly as well as neural manipulation, like chemogenetics, thermogenetics, or optogenetics. The search for the identity of genes expressed as a result of memory acquisition has been an active interest since the origins of behavioral genetics. From screenings of more or less specific candidates to broader studies based on transcriptome analysis, our understanding of the genetic control behind LTM has expanded exponentially in the past years. Here we review recent literature regarding how the formation of memories induces a rapid, extensive and, in many cases, transient wave of transcriptional activity. After a consolidation period, transcriptome changes seem more stable and likely represent the synthesis of new proteins. The complexity of the circuitry involved in memory formation and consolidation is such that there are localized changes in neural activity, both regarding temporal dynamics and the nature of neurons and subcellular locations affected, hence inducing specific temporal and localized changes in protein expression. Different types of neurons are recruited at different times into memory traces. In LTM, the synthesis of new proteins is required in specific subsets of cells. This de novo translation can take place in the somatic cytoplasm and/or locally in distinct zones of compartmentalized synaptic activity, depending on the nature of the proteins and the plasticity-inducing processes that occur. We will also review recent advances in understanding how localized changes are confined to the relevant synapse. These recent studies have led to exciting discoveries regarding proteins that were not previously involved in learning and memory processes. This invaluable information will lead to future functional studies on the roles that hundreds of new molecular actors play in modulating neural activity.

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