Molecular characterisation and functional analysis of LsChi2, a chitinase found in the salmon louse (Lepeophtheirus salmonis salmonis, Krøyer 1838)

Eichner, Christiane; Harasimczuk, Ewa; Nilsen, Frank; Grotmol, Sindre; Dalvin, Sussie

doi:10.1016/j.exppara.2015.01.011

Cited by 26 publications

(14 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cht2 and Idgf6 genes offer new targets for a gene specific search of insecticides, since the epithelial barrier was impaired and resulted in a premature lethality of animals and a higher susceptibility to pathogenic infections. Homologues of the family18 genes exist in parasites and pest harmful to mankind and agriculture, such as mosquitos, lice and the spotted wing Drosophila 50 51 52 . Blast searches showed that parts of the C-terminus of Cht2 and the N-terminus of Idgf6 were not conserved among the insects providing a specific target for insecticides ( Supplementary Fig.…”

Section: Discussionmentioning

confidence: 99%

Chitinases and Imaginal disc growth factors organize the extracellular matrix formation at barrier tissues in insects

Pesch

Riedel

Patil

et al. 2016

Sci Rep

117

169

View full text Add to dashboard Cite

The cuticle forms an apical extracellular-matrix (ECM) that covers exposed organs, such as epidermis, trachea and gut, for organizing morphogenesis and protection of insects. Recently, we reported that cuticle proteins and chitin are involved in ECM formation. However, molecular mechanisms that control assembly, maturation and replacement of the ECM and its components are not well known. Here we investigated the poorly described glyco-18-domain hydrolase family in Drosophila and identified the Chitinases (Chts) and imaginal-disc-growth-factors (Idgfs) that are essential for larval and adult molting. We demonstrate that Cht and idgf depletion results in deformed cuticles, larval and adult molting defects, and insufficient protection against wounding and bacterial infection, which altogether leads to early lethality. We show that Cht2/Cht5/Cht7/Cht9/Cht12 and idgf1/idgf3/idgf4/idgf5/idgf6 are needed for organizing proteins and chitin-matrix at the apical cell surface. Our data indicate that normal ECM formation requires Chts, which potentially hydrolyze chitin-polymers. We further suggest that the nonenzymatic idgfs act as structural proteins to maintain the ECM scaffold against chitinolytic degradation. Conservation of Chts and Idgfs proposes analogous roles in ECM dynamics across the insect taxa, indicating that Chts/Idgfs are new targets for species specific pest control.The epithelial apical extracellular matrix (ECM) controls development and structural maintenance of organisms, organ morphogenesis, wound healing, cell signaling, and the local defense barrier against a hostile environment 1,2 . Numerous events, such as tissue metamorphosis and remodeling, require dynamic alterations and degradations of the ECM architecture. Epithelial cells secrete essential components, such as proteins, lipids and polysaccharides, into the extracellular space where they form a complex network of proteins and proteoglycans. These extracellular components, together with apical membrane bound proteins, organize the ECM as a first barrier at the epithelial cell surface 2-5 .In mice and humans mutations of the extracellular collagen and the cornified envelope have been linked to skin disorder diseases, characterized by skin fragility, painful wounding and accompanied skin infections. The skin layers establish stability and an essential protective barrier by crosslinking of extracellular components 5,6 . In chitinous invertebrates, the ECM barrier is represented by the cuticle, an exoskeleton that covers the body and internal organs as an epithelial surface layer 7,8 . The cuticle is a highly organized ECM structure composed of the polysaccharide chitin and a variety of proteins and enzymes 4 . This exoskeleton is essential for body size control, epithelial barrier formation, epidermal wound healing and protects cells from direct contact with pathogens, toxins or pesticides 1,9,10 . It further provides barriers for maintaining homeostasis of body fluids 11 .Genes involved in the biosynthesis and secretion of chitin-ECM components h...

show abstract

Section: Discussionmentioning

confidence: 99%

Chitinases and Imaginal disc growth factors organize the extracellular matrix formation at barrier tissues in insects

Pesch

Riedel

Patil

et al. 2016

Sci Rep

117

169

View full text Add to dashboard Cite

show abstract

“…The expression patterns of three recently characterized chitinases (LsChi1, LSChi2 and LsChi4) (Eichner, Harasimczuk, Nilsen, Grotmol, & Dalvin, ) are shown in Figure S8. While LsChi2 and LsChi4 are up‐regulated in old and moulting lice, LsChi1 shows a more variable pattern with higher expression in chalimus 1 and old preadult 1 female lice.…”

Section: Discussionmentioning

confidence: 99%

RNA sequencing reveals distinct gene expression patterns during the development of parasitic larval stages of the salmon louse (Lepeophtheirus salmonis)

Eichner

Dondrup

Nilsen

2018

Journal of Fish Diseases

View full text Add to dashboard Cite

The salmon louse (Lepeophtheirus salmonis), an ectoparasitic copepod on salmonids, has become a major threat for the aquaculture industry. In search for new drugs and vaccines, transcriptome analysis is increasingly used to find differently regulated genes and pathways in response to treatment. However, the underlying gene expression changes going along with developmental processes could confound such analyses. The life cycle of L. salmonis consists of eight stages divided by moults. The developmental rate of salmon lice on the host is not uniform. Individual- and sex-related differences are found leading to individuals of unlike developmental status at same sampling time point after infection. In this study, we analyse L. salmonis from a time series by RNA sequencing applying a method of separating individuals of different instar age independent of sampling time point. Lice of four stages divided into up to four age groups within the stage were analysed in triplicate (total of 66 samples). Gene expression analysis shows that the method for sorting individuals was successful. Many genes show cyclic expression patterns over the moulting cycles. Overall gene expression differs more between lice of different age within the same stage than between lice of different stage but same instar age.

show abstract

“…90 The chitinolytic genes and enzymes have been identified in a wide range of insects [104][105][106][107][108][109][110][111][112][113][114][115][116][117][118] and crustacean species, except for Allotriocarida. [119][120][121][122][123][124][125][126][127][128][129][130][131][132][133][134][135][136][137] The activities of chitinolytic enzymes positively rely on the rising 20E titer, with chitobiase being induced earlier at relatively lower 20E level and chitinases being induced when the 20E level peaks. 106,138 The EcREs have not been identified in the sequences of genes encoding the chitinolytic enzymes, 90 indicating the possibility of indirect transcriptional regulation by EcR.…”

Section:  Neuroendocrine Regulation Of Moltingmentioning

confidence: 99%

Ecdysone Receptor Agonism Leading to Lethal Molting Disruption in Arthropods: Review and Adverse Outcome Pathway Development

Shang

Villeneuve

Toyota

et al. 2017

Environ. Sci. Technol.

116

View full text Add to dashboard Cite

Molting is critical for growth, development, reproduction, and survival in arthropods. Complex neuroendocrine pathways are involved in the regulation of molting and may potentially become targets of environmental endocrine disrupting chemicals (EDCs). Based on several known ED mechanisms, a wide range of pesticides has been developed to combat unwanted organisms in food production activities such as agriculture and aquaculture. Meanwhile, these chemicals may also pose hazards to nontarget species by causing molting defects, and thus potentially affecting the health of the ecosystems. The present review summarizes the available knowledge on molting-related endocrine regulation and chemically mediated disruption in arthropods (with special focus on insects and crustaceans), to identify research gaps and develop a mechanistic model for assessing environmental hazards of these compounds. Based on the review, multiple targets of EDCs in the molting processes were identified and the link between mode of action (MoA) and adverse effects characterized to inform future studies. An adverse outcome pathway (AOP) describing ecdysone receptor agonism leading to incomplete ecdysis associated mortality was developed according to the OECD guideline and subjected to weight of evidence considerations by evolved Bradford Hill Criteria. This review proposes the first invertebrate ED AOP and may serve as a knowledge foundation for future environmental studies and AOP development.

show abstract

Molecular characterisation and functional analysis of LsChi2, a chitinase found in the salmon louse (Lepeophtheirus salmonis salmonis, Krøyer 1838)

Cited by 26 publications

References 47 publications

Chitinases and Imaginal disc growth factors organize the extracellular matrix formation at barrier tissues in insects

Chitinases and Imaginal disc growth factors organize the extracellular matrix formation at barrier tissues in insects

RNA sequencing reveals distinct gene expression patterns during the development of parasitic larval stages of the salmon louse (Lepeophtheirus salmonis)

Ecdysone Receptor Agonism Leading to Lethal Molting Disruption in Arthropods: Review and Adverse Outcome Pathway Development

Contact Info

Product

Resources

About