Search results for "ECU"

Epigenetic and Genetic Contributions to Adaptation in Chlamydomonas

2017

Epigenetic modifications, such as DNA methylation or histone modifications, can be transmitted between cellular or organismal generations. However, there are no experiments measuring their role in adaptation, so here we use experimental evolution to investigate how epigenetic variation can contribute to adaptation. We manipulated DNA methylation and histone acetylation in the unicellular green alga Chlamydomonas reinhardtii both genetically and chemically to change the amount of epigenetic variation generated or transmitted in adapting populations in three different environments (salt stress, phosphate starvation, and high CO2) for two hundred asexual generations. We find that reducing the …

Intensive Management and Natural Genetic Variation in Red Deer (Cervus elaphus)

2017

The current magnitude of big-game hunting has outpaced the natural growth of populations, making artificial breeding necessary to rapidly boost hunted populations. In this study, we evaluated if the rapid increase of red deer (Cervus elaphus) abundance, caused by the growing popularity of big-game hunting, has impacted the natural genetic diversity of the species. We compared several genetic diversity metrics between 37 fenced populations subject to intensive management and 21 wild free-ranging populations. We also included a historically protected population from a national park as a baseline for comparisons. Contrary to expectations, our results showed no significant differences in geneti…

Genetic diversity of Rhizoctonia solani associated with potato tubers in France.

2011

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; The soilborne fungus Rhizoctonia solani is a pathogen of many plants and causes severe damage in crops around the world. Strains of R. solani from the anastomosis group (AG) 3 attack potatoes, leading to great yield losses and to the downgrading of production. The study of the genetic diversity of the strains of R. solani in France allows the structure of the populations to be determined and adapted control strategies against this pathogen to be established. …

New multilocus phylogeny reorganises the family Macrobiotidae (Eutardigrada) and unveils complex morphological evolution of the Macrobiotus hufelandi…

2021

The family Macrobiotidae is one of the most speciose and diverse groups among tardigrades. Although there have been attempts to reconstruct the phylogeny of this family, the evolutionary relationships within Macrobiotidae are only superficially determined as available genetic data cover only a small fraction of this vast group. Here, we present the first extensive molecular phylogeny of the family based on four molecular markers (18S rRNA, 28Sr RNA, ITS-2 and COI) associated with detailed morphological data for the majority of taxa. The phylogenetic analysis includes nearly two hundred sequences representing more than sixty species, including sixteen taxa that have never been sequenced and/…

Random Genetic Drift and Selective Pressures Shaping the Blattabacterium Genome

2018

AbstractEstimates suggest that at least half of all extant insect genera harbor obligate bacterial mutualists. Whereas an endosymbiotic relationship imparts many benefits upon host and symbiont alike, the intracellular lifestyle has profound effects on the bacterial genome. The obligate endosymbiont genome is a product of opposing forces: genes important to host survival are maintained through physiological constraint, contrasted by the fixation of deleterious mutations and genome erosion through random genetic drift. The obligate cockroach endosymbiont, Blattabacterium – providing nutritional augmentation to its host in the form of amino acid synthesis – displays radical genome alterations…

Evaluating responses to temperature during pre-metamorphosis and carry-over effects at post-metamorphosis in the wood tiger moth (Arctia plantaginis)

2019

Insect metamorphosis is one of the most recognized processes delimiting transitions between phenotypes. It has been traditionally postulated as an adaptive process decoupling traits between life stages, allowing evolutionary independence of pre- and post-metamorphic phenotypes. However, the degree of autonomy between these life stages varies depending on the species and has not been studied in detail over multiple traits simultaneously. Here, we reared full-sib larvae of the warningly coloured wood tiger moth ( Arctia plantaginis ) in different temperatures and examined their responses for phenotypic (melanization change, number of moults), gene expression (RNA-seq and qPCR of candidate ge…

2018

BackgroundThe insect cuticle covers the whole body and all appendages and has bi-directionnal selective permeability: it protects against environmental stress and pathogen infection and also helps to reduce water loss. The adult cuticle is often associated with a superficial layer of fatty acid-derived molecules such as waxes and long chain hydrocarbons that prevent rapid dehydration. The waterproofing properties of cuticular hydrocarbons (CHs) depend on their chain length and desaturation number.DrosophilaCH biosynthesis involves an enzymatic pathway including several elongase and desaturase enzymes.MethodsThe link between desiccation resistance and CH profile remains unclear, so we tested…

Foraging behaviour of an egg parasitoid exploiting plant volatiles induced by pentatomids : The role of adaxial and abaxial leaf surfaces

2017

Several phases of herbivorous insect attack including feeding and oviposition are known to induce plant defenses. Plants emit volatiles induced by herbivores to recruit insect parasitoids as an indirect defense strategy. So far, volatiles induced by herbivore walking and their putative role in the foraging behavior of egg parasitoids have not been investigated. In this paper we studied the response of the egg parasitoid Trissolcus basalis toward volatiles emitted by Vicia faba plants as consequence of the walking activity of the host Nezara viridula. Olfactometer bioassays were carried out to evaluate wasp responses to plants in which the abaxial or the adaxial surfaces were subjected to wa…

The current and future state of animal coloration research

2017

Animal colour patterns are a model system for understanding evolution because they are unusually accessible for study and experimental manipulation. This is possible because their functions are readily identifiable. In this final paper of the symposium we provide a diagram of the processes affecting colour patterns and use this to summarize their functions and put the other papers in a broad context. This allows us to identify significant ‘holes’ in the field that only become obvious when we see the processes affecting colour patterns, and their interactions, as a whole. We make suggestions about new directions of research that will enhance our understanding of both the evolution of colour …

Hemocyanin genes as indicators of habitat shifts in Panpulmonata?

2018

Hemocyanin is the primary respiratory protein for the majority of the Mollusca and therefore directly interfaces with the physiological requirements of each species and the environments to which they are adapted. Hemocyanin is therefore likely to have been evolutionarily imprinted by significant habitat shifts. In the gastropod clade Panpulmonata (>30,000 species) major realm transitions have occurred multiple times independently and may have contributed to the diversification of this group. Yet, little is known about the adaptive changes linked to these habitat shifts. In order to gain deeper insight into the evolution of panpulmonate hemocyanins and to infer possible impacts associated wi…