Search results for "Molecular"

Hop stunt viroid: A polyphagous pathogenic RNA that has shed light on viroid–host interactions

2021

[Taxonomy]: Hop stunt viroid (HSVd) is the type species of the genus Hostuviroid (family Pospiviroidae). The other species of this genus is Dahlia latent viroid, which presents an identical central conserved region (CCR) but lacks other structural hallmarks present in Hop stunt viroid. HSVd replication occurs in the nucleus through an asymmetric rolling-circle model as in the other members of the family Pospiviroidae, which also includes the genera Pospiviroid, Cocadviroid, Apscaviroid, and Coleoviroid.

Arabidopsis RCD1 coordinates chloroplast and mitochondrial functions through interaction with ANAC transcription factors

2019

Reactive oxygen species (ROS)-dependent signaling pathways from chloroplasts and mitochondria merge at the nuclear protein RADICAL-INDUCED CELL DEATH1 (RCD1). RCD1 interacts in vivo and suppresses the activity of the transcription factors ANAC013 and ANAC017, which mediate a ROS-related retrograde signal originating from mitochondrial complex III. Inactivation of RCD1 leads to increased expression of mitochondrial dysfunction stimulon (MDS) genes regulated by ANAC013 and ANAC017. Accumulating MDS gene products, including alternative oxidases (AOXs), affect redox status of the chloroplasts, leading to changes in chloroplast ROS processing and increased protection of photosynthetic apparatus.…

Hierarchical networks of food exchange in the black garden ant Lasius niger

2020

In most eusocial insects, the division of labour results in relatively few individuals foraging for the entire colony. Thus, the survival of the colony depends on its efficiency in meeting the nutritional needs of all its members. Here, we characterise the network topology of a eusocial insect to understand the role and centrality of each caste in this network during the process of food dissemination. We constructed trophallaxis networks from 34 food-exchange experiments in black garden ants (Lasius niger). We tested the influence of brood and colony size on (i) global indices at the network level (i.e. efficiency, resilience, centralisation and modularity) and (ii) individual values (i.e. …

Le monoxyde d’azote

2013

Le monoxyde d’azote (NO) est un mediateur physiologique associe a divers processus chez les animaux, dont l’immunite. Des travaux conduits recemment montrent que les plantes, confrontees a l’attaque d’agents pathogenes, produisent egalement du NO. Le NO est donc un acteur des voies de signalisation cellulaire activees en reponse a la reconnaissance par les plantes d’agresseurs exterieurs. L’etude des molecules cibles du NO et, plus particulierement, la caracterisation de proteines S-nitrosylees, a permis d’avoir un premier apercu des mecanismes fins inherents a ses fonctions. Le NO serait ainsi implique dans l’activation ainsi que dans la desensibilisation des voies de signalisation mobilis…

2019

Abstract A better understanding of the environmental and genetic contribution to migratory behavior and the evolution of traits linked to migration is crucial for fish conservation and fisheries management. Up to date, a few genes with unequivocal influence on the adoption of alternative migration strategies have been identified in salmonids. Here, we used a common garden set-up to measure individual migration distances of generally highly polymorphic brown trout Salmo trutta from two populations. Fish from the assumedly resident population showed clearly shorter migration distances than the fish from the assumed migratory population at the ages of 2 and 3 years. By using two alternative an…

2019

RNA interference (RNAi) is a powerful tool for studying functions of candidate genes in both model and nonmodel organisms and a promising technique for therapeutic applications. Successful application of this technique relies on the accuracy and reliability of methods used to quantify gene knockdown. With the limitation in the availability of antibodies for detecting proteins, quantitative PCR (qPCR) remains the preferred method for quantifying target gene knockdown after dsRNA treatment. We evaluated how qPCR primer binding site and target gene expression levels affect quantification of intact mRNA transcripts following dsRNA-mediated RNAi. The use of primer pairs targeting the mRNA sequen…

Acclimation capacity and rate change through life in the zooplankton Daphnia

2020

When a change in the environment occurs, organisms can maintain an optimal phenotypic state via plastic, reversible changes to their phenotypes. These adjustments, when occurring within a generation, are described as the process of acclimation. While acclimation has been studied for more than half a century, global environmental change has stimulated renewed interest in quantifying variation in the rate and capacity with which this process occurs, particularly among ectothermic organisms. Yet, despite the likely ecological importance of acclimation capacity and rate, how these traits change throughout life among members of the same species is largely unstudied. Here we investigate these re…

2021

We report the assembly and annotation of the complete mitochondrial genome of the warningly-coloured wood tiger moth (Arctia plantaginis) and investigate its phylogenetic position within Arctiinae. The A.plantaginis mitogenome is 15,479 bp long with 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNA genes, and an A + T-rich region (D-loop). The phylogenetic analyses based on 13 protein-coding genes showed A.plantaginis clustering within a clade of species with white wings and yellow or red bodies. This result can be useful in understanding the evolution of coloration in Arctiid moths.

2014

The Vipp1 protein is essential in cyanobacteria and chloroplasts for the maintenance of photosynthetic function and thylakoid membrane architecture. To investigate its mode of action we generated strains of the cyanobacteria Synechocystis sp. PCC6803 and Synechococcus sp. PCC7942 in which Vipp1 was tagged with green fluorescent protein at the C-terminus and expressed from the native chromosomal locus. There was little perturbation of function. Live-cell fluorescence imaging shows dramatic relocalisation of Vipp1 under high light. Under low light, Vipp1 is predominantly dispersed in the cytoplasm with occasional concentrations at the outer periphery of the thylakoid membranes. High light ind…

Evolutionary history of two allopatric Terricola species (Arvicolinae, Rodentia) from molecular, morphological, and palaeontological data

2008

To investigate the phylogenetic and phylogeographical relationships of arvicolines, we use several Western European ground voles. More particularly, our study is focused on Microtus (Terricola) savii and M. (T.) pyrenaicus. These two allopatric species are usually considered as having originated from the same ancestor, possibly M. (T.) mariaclaudiae. We propose molecular and morphological approaches: nucleotidic data from the mitochondrial cytochrome b and 12S rRNA genes and global morphological analyses from the first lower molar. Four other Terricola species (multiplex, lusitanicus, duodecimcostatus, subterraneus) were added to the data set for both analyses, and two other vole species (C…