Search results for "NET"
showing 10 items of 55461 documents
Heterozygote advantage and pleiotropy contribute to intraspecific color trait variability
2022
The persistence of intrapopulation phenotypic variation typically requires some form of balancing selection because drift and directional selection eventually erode genetic variation. Heterozygote advantage remains a classic explanation for the maintenance of genetic variation in the face of selection. However, examples of heterozygote advantage, other than those associated with disease resistance, are rather uncommon. Across most of its distribution, males of the aposematic moth Arctia plantaginis have two hindwing phenotypes determined by a heritable one locus-two allele polymorphism (genotypes: WW/Wy = white morph, yy = yellow morph). Using genotyped moths, we show that the presence of o…
Defense against predators incurs high reproductive costs for the aposematic moth Arctia plantaginis
2020
Abstract To understand how variation in warning displays evolves and is maintained, we need to understand not only how perceivers of these traits select color and toxicity but also the sources of the genetic and phenotypic variation exposed to selection by them. We studied these aspects in the wood tiger moth Arctia plantaginis, which has two locally co-occurring male color morphs in Europe: yellow and white. When threatened, both morphs produce defensive secretions from their abdomen and from thoracic glands. Abdominal fluid has shown to be more important against invertebrate predators than avian predators, and the defensive secretion of the yellow morph is more effective against ants. Her…
The impact of life stage and pigment source on the evolution of novel warning signal traits
2021
Our understanding of how novel warning color traits evolve in natural populations is largely based on studies of reproductive stages and organisms with endogenously produced pigmentation. In these systems, genetic drift is often required for novel alleles to overcome strong purifying selection stemming from frequency-dependent predation and positive assortative mating. Here, we integrate data from field surveys, predation experiments, population genomics, and phenotypic correlations to explain the origin and maintenance of geographic variation in a diet-based larval pigmentation trait in the redheaded pine sawfly (Neodiprion lecontei), a pine-feeding hymenopteran. Although our experiments c…
Diversity in warning coloration: selective paradox or the norm?
2019
Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency-dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in the same population. Recent research has yielded an increased awareness of this diversity, challenging the paradigm of signal monomorphy in aposematic animals. Here we provide a comprehensive synthesis of these disparate lines of investigation, identifying within them three broad classes of explanation for variation in aposematic warning signals: …
The complete mitochondrial genome of the wood tiger moth (Arctia plantaginis) and phylogenetic analyses within Arctiinae
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. Peer reviewed
Vascular Risk Factors in Mild Cognitive Impairment Subtypes
2007
<i>Background and Aim:</i> To investigate the role of vascular risk factors in different subtypes of mild cognitive impairment (MCI) in a multicentric, clinic-based, cross-sectional study. <i>Methods:</i> Two-hundred and seven subjects with MCI were included in the study: 33 with single non-memory MCI (snmMCI), 42 with multiple-domain amnestic MCI (mdMCI-a) and 132 with amnestic MCI (aMCI). Several clinical vascular risk factors and magnetic resonance imaging (MRI) brain lesions were evaluated. <i>Results:</i> snmMCI showed a higher frequency of ischaemic heart disease and of transient ischaemic attack (TIA)/stroke, a higher Hachinski ischaemic score and …
Model organisms and their application in environmental epigenetics
2020
Abstract Epigenetic mechanisms operate at the interface between the environment and the genome of a given organism. More particularly, they convert environmental stimuli as diverse as chemical pollutants, nutritional components, temperature changes, and social conditions into changes in the chromatin landscape, which influence gene expression in the absence of alterations in the DNA sequence, ultimately leading to phenotype adaptation and diversification. The use of experimental model organisms in epigenetics research allows for the careful manipulation of environmental factors in order to understand how they mechanistically modulate the establishment, maintenance, and inheritance of epigen…
The role of lipid metabolism in the acquisition of desiccation tolerance inCraterostigma plantagineum: a comparative approach
2013
Summary Dehydration leads to different physiological and biochemical responses in plants. We analysed the lipid composition and the expression of genes involved in lipid biosynthesis in the desiccation-tolerant plant Craterostigma plantagineum. A comparative approach was carried out with Lindernia brevidens (desiccation tolerant) and two desiccation-sensitive species, Lindernia subracemosa and Arabidopsis thaliana. In C. plantagineum the total lipid content remained constant while the lipid composition underwent major changes during desiccation. The most prominent change was the removal of monogalactosyldiacylglycerol (MGDG) from the thylakoids. Analysis of molecular species composition rev…
The Developmental Transcriptome for Lytechinus variegatus Exhibits Temporally Punctuated Gene Expression Changes
2019
AbstractEmbryonic development is arguably the most complex process an organism undergoes during its lifetime, and understanding this complexity is best approached with a systems-level perspective. The sea urchin has become a highly valuable model organism for understanding developmental specification, morphogenesis, and evolution. As a non-chordate deuterostome, the sea urchin occupies an important evolutionary niche between protostomes and vertebrates.Lytechinus variegatus(Lv) is an Atlantic species that has been well studied, and which has provided important insights into signal transduction, patterning, and morphogenetic changes during embryonic and larval development. The Pacific specie…
CYGD: the Comprehensive Yeast Genome Database.
2005
The comprehensive resource is available under http://mips.gsf.de/genre/proj/yeast/.; International audience; The Comprehensive Yeast Genome Database (CYGD) compiles a comprehensive data resource for information on the cellular functions of the yeast Saccharomyces cerevisiae and related species, chosen as the best understood model organism for eukaryotes. The database serves as a common resource generated by a European consortium, going beyond the provision of sequence information and functional annotations on individual genes and proteins. In addition, it provides information on the physical and functional interactions among proteins as well as other genetic elements. These cellular network…