Search results for "INS"
showing 10 items of 35719 documents
Mutations in voltage-gated sodium channels from pyrethroid resistant salmon lice (Lepeophtheirus salmonis)
2018
BACKGROUND Parasitic salmon lice (Lepeophtheirus salmonis) cause high economic losses in Atlantic salmon farming. Pyrethroids, which block arthropod voltage-gated sodium channels (Nav 1), are used for salmon delousing. However, pyrethroid resistance is common in L. salmonis. The present study characterized Nav 1 homologues in L. salmonis in order to identify channel mutations associated to resistance, called kdr (knockdown) mutations. RESULTS Genome scans identified three L. salmonis Nav 1 homologues, LsNav 1.1, LsNav 1.2 and LsNav 1.3. Arthropod kdr mutations map to specific Nav 1 regions within domains DI-III, namely segments S5 and S6 and the linker helix connecting S4 and S5. The above …
Genetic variation in natural populations of the aphid Rhopalosiphum padi as revealed by maternally inherited markers
1996
A survey on 148 clones of the aphid Rhopalosiphum padi from 11 widespread localities has been carried out to study the genetic structure of populations of this species as revealed by mitochondrial DNA restriction site and length polymorphisms as well as by restriction site analysis of a maternally inherited plasmid carried by the aphid eubacterial endosymbiont Buchnera aphidicola. Our results support the existence in the area under study of two main aphid maternal lineages strikingly coincidental with the two main reproductive categories displayed by this species. Those aphid clones possessing an incomplete life cycle that lacks the sexual phase (anholocyclic or androcyclic clones) show mit…
The tiny eukaryote Ostreococcus provides genomic insights into the paradox of plankton speciation
2007
The smallest known eukaryotes, at ≈1-μm diameter, are Ostreococcus tauri and related species of marine phytoplankton. The genome of Ostreococcus lucimarinus has been completed and compared with that of O. tauri . This comparison reveals surprising differences across orthologous chromosomes in the two species from highly syntenic chromosomes in most cases to chromosomes with almost no similarity. Species divergence in these phytoplankton is occurring through multiple mechanisms acting differently on different chromosomes and likely including acquisition of new genes through horizontal gene transfer. We speculate that this latter process may be involved in altering the cell-surface character…
Disentangling phylogeography, polyploid evolution and taxonomy of a woodland herb (Veronica chamaedrys group, Plantaginaceae s.l.) in southeastern Eu…
2010
Southeastern Europe is a centre of European biodiversity, but very little is known about factors causing the observed richness. Here, we contribute to fill this gap by reconstructing the spatio-temporal diversification of the cytologically variable and taxonomically intricate complex of Veronica chamaedrys (Plantaginaceae s.l.), growing in open forests, forest edges and grasslands, with flow cytometry, molecular markers (AFLPs, plastid DNA sequences) and morphometry. Our results show that both diploid and tetraploid cytotypes are widespread, but diploids predominate on the southern Balkan Peninsula. Plastid sequences suggest a first split into three main lineages in the mid-Pleistocene and …
p24 Family Proteins Are Involved in Transport to the Plasma Membrane of GPI-Anchored Proteins in Plants
2020
p24 proteins are a family of type-I membrane proteins that cycle between the endoplasmic reticulum (ER) and the Golgi apparatus via Coat Protein I (COPI)- and COPII-coated vesicles. These proteins have been proposed to function as cargo receptors, but the identity of putative cargos in plants is still elusive. We previously generated an Arabidopsis (Arabidopsis thaliana) quadruple loss-of-function mutant affecting p24 genes from the δ-1 subclass of the p24 delta subfamily (p24δ3δ4δ5δ6 mutant). This mutant also had reduced protein levels of other p24 family proteins and was found to be sensitive to salt stress. Here, we used this mutant to test the possible involvement of p24 proteins in the…
Evidence for a recent horizontal transmission and spatial spread of Wolbachia from endemic Rhagoletis cerasi (Diptera: Tephritidae) to invasive Rhago…
2013
The widespread occurrence of Wolbachia in arthropods and nematodes suggests that this intracellular, maternally inherited endosymbiont has the ability to cross species boundaries. However, direct evidence for such a horizontal transmission of Wolbachia in nature is scarce. Here, we compare the well-characterized Wolbachia infection of the European cherry fruit fly, Rhagoletis cerasi, with that of the North American eastern cherry fruit fly, Rhagoletis cingulata, recently introduced to Europe. Molecular genetic analysis of Wolbachia based on multilocus sequence typing and the Wolbachia surface protein wsp showed that all R. cingulata individuals are infected with wCin2 identical to wCer2 in …
Grazing and abandonment determine different tree dynamics in wood-pastures
2016
Wood-pastures are threatened biotopes in which trees and livestock grazing maintain high conservation values. However, browsing may threaten tree regeneration, whereas abandonment leads to tree encroachment. We studied the regeneration of trees in a grazed and abandoned boreal wood-pastures. In grazed sites, the density of young spruces (Picea abies) was high, while the density of young birches (Betula spp.) was very low. Sprucification can be prevented only by removing spruces. The number of young birches and pines (Pinus sylvestris) was correlated with the number of junipers (Juniperus communis), probably because thorny junipers protect palatable seedlings from browsing. In abandoned site…
Acting locally - affecting globally: RNA sequencing of gilthead sea bream with a mild Sparicotyle chrysophrii infection reveals effects on apoptosis,…
2019
[Background] Monogenean flatworms are the main fish ectoparasites inflicting serious economic losses in aquaculture. The polyopisthocotylean Sparicotyle chrysophrii parasitizes the gills of gilthead sea bream (GSB, Sparus aurata) causing anaemia, lamellae fusion and sloughing of epithelial cells, with the consequent hypoxia, emaciation, lethargy and mortality. Currently no preventive or curative measures against this disease exist and therefore information on the host-parasite interaction is crucial to find mitigation solutions for sparicotylosis. The knowledge about gene regulation in monogenean-host models mostly comes from freshwater monopysthocotyleans and almost nothing is known about …
Triterpene glycosides from Blighia welwitschii and evaluation of their antibody recognition capacity in multiple sclerosis
2020
Multiple sclerosis (MS) in a multifactorial autoimmune disease in which reliable biomarkers are needed for therapeutic monitoring and diagnosis. Autoantibodies (autoAbs) are known biomarker candidates although their detection in biological fluids requires a thorough characterization of their associated antigens. Over the past twenty years, a reverse chemical-based approach aiming to screen putative autoantigens has underlined the role of glycans, in particular glucose, in MS. Despite the progress achieved, a lack of consensus regarding the nature of innate antigens as well as difficulties proposing new synthetic glucose-based structures have proved to be obstacles. Here is proposed a strate…
Changes in lipid composition in tobacco cells treated with cryptogein , an elicitor from Phytophthora cryptogea
1995
Abstract Changes in lipid composition occurred when tobacco cells (Nicotiana tabacum var. Xanthi) were treated with cryptogein, a proteinaceous elicitor from Phytophthora cryptogea. The most striking change was an increase in acylated steryl glycosides and steryl esters levels, certainly resulting from the glycosylation and/or esterification of free sterols. Moreover, in vivo pulse-labelling experiments with [14C]acetate also showed that a progressive decline in the incorporation rate of [14C]acetate into free sterols started with the induction of sesquiterpenoid synthesis and lasted when sesquiterpenoid synthesis stops. This phenomenon was accompanied by a significant increase in the synth…