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 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.

Ontogenetic changes in visual sensitivity of the parasitic salmon louse Lepeophtheirus salmonis

2000 ◽  
Vol 203 (11) ◽  
pp. 1649-1657 ◽  
Author(s):  
I. Novales Flamarique ◽  
H.I. Browman ◽  
M. Belanger ◽  
K. Boxaspen
Keyword(s):  
Spectral Range ◽  
Developmental Stages ◽  
Polarized Light ◽  
Bright Light ◽  
Visual Sensitivity ◽  
Spectral Irradiance ◽  
Lepeophtheirus Salmonis ◽  
Ontogenetic Changes ◽  
Salmon Louse ◽  
Salmon Lice

The salmon louse, Lepeophtheirus salmonis, is an ectoparasitic copepod of salmonid fishes whose life cycle involves two broadly defined, free-living larval stages, the nauplius and the copepodid. After settling on a host, the copepodid goes through various transformations to become a mobile adult. We recorded swimming responses of free-swimming salmon lice at the naupliar, copepodid and adult stages to the onset (ON) and offset (OFF) of lights of varying spectral irradiance and polarization. Nauplii showed a prominent swim-up OFF response across the spectrum 352–652 nm, but no ON response. Copepodids exhibited a swim-up ON response and a passive (sinking) OFF response across the same spectral range. Adults showed active swim-up responses to both ON and OFF stimuli, although the OFF response was proportionately stronger. The spectral range of the adult ON and OFF responses was the same as that of the copepodids and slightly greater than that of the nauplii, which did not exhibit responses at 652 nm. The absolute sensitivity of copepodids under white light (approx. 10(−13) photons m(2) s(1)) was higher than that of nauplii (approx. 10(−17) photons(−1) m(2)s, OFF response) and that of adult female lice (approx. 10(−14) photons(−1)m(2)s). This suggests that the naupliar visual system is best suited for detection of shadows (e.g. the host) under a bright light field (daylight hours), while copepodids and adults may be more specialized for host detection at crepuscular periods and during the night, when light levels are low. None of the developmental stages responded to the rotation of the plane of polarized light or exhibited any difference in directed response when polarized light was used in place of diffuse light.

scholarly journals RNAi mediated myosuppressin deficiency affects muscle development and survival in the salmon louse (Lepeophtheirus salmonis)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anna Z. Komisarczuk ◽  
Heidi Kongshaug ◽  
Ming Li ◽  
Frank Nilsen
Keyword(s):  
Muscle Development ◽  
Developmental Stages ◽  
Intestinal Wall ◽  
Lepeophtheirus Salmonis ◽  
Inhibitory Effects ◽  
Salmon Louse ◽  
Physiological Processes ◽  
Severe Reduction ◽  
The Central Nervous System ◽  
Contraction And Relaxation

Abstract Muscle activity is regulated by stimulatory and inhibitory neuropeptides allowing for contraction and relaxation. In Arthropods, one of the important myoinhibitors is Myosuppressin, belonging to FMRFamide-like peptides, that was shown to have inhibitory effects on visceral muscle contraction and to regulate vital physiological processes including reproduction or feeding. We have identified myosuppressin in salmon louse Lepeophtheirus salmonis (LsalMS) and systematically characterised its function and complex abnormalities emerging after LsalMS knockdown by RNAi in all developmental stages in this species. Immunohistochemistry analysis localized the LsalMS mainly to the central nervous system, but also to the vital organs within the alimentary tract and the reproductive system. The most striking feature of LsalMS deficiency during lice development was severe reduction of the muscle content, with abnormalities detected in both the visceral and skeletal muscles. Moreover, down-regulation of LsalMS affects moulting, spermatophore deposition and feeding by affecting development of the intestinal wall and increasing its contraction frequency.

scholarly journals Integrated transcriptomic and proteomic analysis reveals the complex molecular mechanisms underlying stone cell formation in Korla pear

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aisajan Mamat ◽  
Kuerban Tusong ◽  
Juan Xu ◽  
Peng Yan ◽  
Chuang Mei ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Proteomic Analysis ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Cell Formation ◽  
Parenchyma Cell ◽  
Lignin Biosynthesis ◽  
Cell Content ◽  
Stone Cell ◽  
Fruit Samples

AbstractKorla pear (Pyrus sinkiangensis Yü) is a landrace selected from a hybrid pear species in the Xinjiang Autonomous Region in China. In recent years, pericarp roughening has been one of the major factors that adversely affects fruit quality. Compared with regular fruits, rough-skin fruits have a greater stone cell content. Stone cells compose sclerenchyma tissue that is formed by secondary thickening of parenchyma cell walls. In this work, we determined the main components of stone cells by isolating them from the pulp of rough-skin fruits at the ripening stage. Stone cell staining and apoptosis detection were then performed on fruit samples that were collected at three different developmental stages (20, 50 and 80 days after flowering (DAF)) representing the prime, late and stationary stages of stone cell differentiation, respectively. The same batches of samples were used for parallel transcriptomic and proteomic analysis to identify candidate genes and proteins that are related to SCW biogenesis in Korla pear fruits. The results showed that stone cells are mainly composed of cellulose (52%), hemicellulose (23%), lignin (20%) and a small amount of polysaccharides (3%). The periods of stone cell differentiation and cell apoptosis were synchronous and primarily occurred from 0 to 50 DAF. The stone cell components increased abundantly at 20 DAF but then decreased gradually. A total of 24,268 differentially expressed genes (DEGs) and 1011 differentially accumulated proteins (DAPs) were identified from the transcriptomic and proteomic data, respectively. We screened the DEGs and DAPs that were enriched in SCW-related pathways, including those associated with lignin biosynthesis (94 DEGs and 31 DAPs), cellulose and xylan biosynthesis (46 DEGs and 18 DAPs), S-adenosylmethionine (SAM) metabolic processes (10 DEGs and 3 DAPs), apoplastic ROS production (16 DEGs and 2 DAPs), and cell death (14 DEGs and 6 DAPs). Among the identified DEGs and DAPs, 63 significantly changed at both the transcript and protein levels during the experimental periods. In addition, the majority of these identified genes and proteins were expressed the most at the prime stage of stone cell differentiation, but their levels gradually decreased at the later stages.

scholarly journals Integrative Modelling of Gene Expression and Digital Phenotypes to Describe Senescence in Wheat

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 909
Author(s):  
Anyela Valentina Camargo Rodriguez
Keyword(s):  
Gene Expression ◽  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Computational Modelling ◽  
Plant Morphology ◽  
Reproductive Organs ◽  
Biological Trait ◽  
Cereal Grain ◽  
Plant Level

Senescence is the final stage of leaf development and is critical for plants’ fitness as nutrient relocation from leaves to reproductive organs takes place. Although senescence is key in nutrient relocation and yield determination in cereal grain production, there is limited understanding of the genetic and molecular mechanisms that control it in major staple crops such as wheat. Senescence is a highly orchestrated continuum of interacting pathways throughout the lifecycle of a plant. Levels of gene expression, morphogenesis, and phenotypic development all play key roles. Yet, most studies focus on a short window immediately after anthesis. This approach clearly leaves out key components controlling the activation, development, and modulation of the senescence pathway before anthesis, as well as during the later developmental stages, during which grain development continues. Here, a computational multiscale modelling approach integrates multi-omics developmental data to attempt to simulate senescence at the molecular and plant level. To recreate the senescence process in wheat, core principles were borrowed from Arabidopsis Thaliana, a more widely researched plant model. The resulted model describes temporal gene regulatory networks and their effect on plant morphology leading to senescence. Digital phenotypes generated from images using a phenomics platform were used to capture the dynamics of plant development. This work provides the basis for the application of computational modelling to advance understanding of the complex biological trait senescence. This supports the development of a predictive framework enabling its prediction in changing or extreme environmental conditions, with a view to targeted selection for optimal lifecycle duration for improving resilience to climate change.

scholarly journals Combining QTL Mapping and Gene Expression Analysis to Elucidate the Genetic Control of ‘Crumbly’ Fruit in Red Raspberry (Rubus idaeus L.)

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 794
Author(s):  
Luca M. Scolari ◽  
Robert D. Hancock ◽  
Pete E. Hedley ◽  
Jenny Morris ◽  
Kay Smith ◽  
...  
Keyword(s):  
Genetic Control ◽  
Developmental Disorder ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Microarray Experiment ◽  
Rubus Idaeus ◽  
Red Raspberry ◽  
Genotype By Sequencing ◽  
First Time ◽  
Selection Of

‘Crumbly’ fruit is a developmental disorder in raspberry that results in malformed and unsaleable fruits. For the first time, we define two distinct crumbly phenotypes as part of this work. A consistent crumbly fruit phenotype affecting the majority of fruits every season, which we refer to as crumbly fruit disorder (CFD) and a second phenotype where symptoms vary across seasons as malformed fruit disorder (MFD). Here, segregation of crumbly fruit of the MFD phenotype was examined in a full-sib family and three QTL (Quantitative Trait Loci) were identified on a high density GbS (Genotype by Sequencing) linkage map. This included a new QTL and more accurate location of two previously identified QTLs. A microarray experiment using normal and crumbly fruit at three different developmental stages identified several genes that were differentially expressed between the crumbly and non-crumbly phenotypes within the three QTL. Analysis of gene function highlighted the importance of processes that compromise ovule fertilization as triggers of crumbly fruit. These candidate genes provided insights regarding the molecular mechanisms involved in the genetic control of crumbly fruit in red raspberry. This study will contribute to new breeding strategies and diagnostics through the selection of molecular markers associated with the crumbly trait.

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.

scholarly journals Comparative Transcriptome Analysis Reveals Regulatory Networks during the Maize Ear Shank Elongation Process

2021 ◽  
Vol 22 (13) ◽  
pp. 7029
Author(s):  
Cai-Yun Xiong ◽  
Qing-You Gong ◽  
Hu Pei ◽  
Chang-Jian Liao ◽  
Rui-Chun Yang ◽  
...  
Keyword(s):  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Rna Seq ◽  
Short Branch ◽  
Transcriptional Dynamics ◽  
New Varieties ◽  
Elongation Process ◽  
Temporal Expression Pattern ◽  
Maize Ear

In maize, the ear shank is a short branch that connects the ear to the stalk. The length of the ear shank mainly affects the transportation of photosynthetic products to the ear, and also influences the dehydration of the grain by adjusting the tightness of the husks. However, the molecular mechanisms of maize shank elongation have rarely been described. It has been reported that the maize ear shank length is a quantitative trait, but its genetic basis is still unclear. In this study, RNA-seq was performed to explore the transcriptional dynamics and determine the key genes involved in maize shank elongation at four different developmental stages. A total of 8145 differentially expressed genes (DEGs) were identified, including 729 transcription factors (TFs). Some important genes which participate in shank elongation were detected via function annotation and temporal expression pattern analyses, including genes related to signal transduction hormones (auxin, brassinosteroids, gibberellin, etc.), xyloglucan and xyloglucan xyloglucosyl transferase, and transcription factor families. The results provide insights into the genetic architecture of maize ear shanks and developing new varieties with ideal ear shank lengths, enabling adjustments for mechanized harvesting in the future.

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