eQTL mapping in transgenic alpha-synuclein carrying Caenorhabditis elegans recombinant inbred lines.

Protein aggregation of α-synuclein (αS) is a genetic and neuropathological hallmark of Parkinson's disease (PD). Studies in the model nematode Caenorhabditis elegans suggested that variation of αS aggregation depends on the genetic background. However, which genes and genetic modifiers underlie individual differences in αS pathology remains unknown.

Cryptic genetic variation of expression quantitative trait locus architecture revealed by genetic perturbation in Caenorhabditis elegans.

Genetic perturbation in different genetic backgrounds can cause a range of phenotypes within a species. These phenotypic differences can be the result of the interaction between the genetic background and the perturbation. Previously, we reported that perturbation of gld-1, an important player in the developmental control of Caenorhabditis elegans, released cryptic genetic variation (CGV) affecting fitness in different genetic backgrounds.

Determining Toxic Potencies of Water-Soluble Contaminants in Wastewater Influents and Effluent Using Gene Expression Profiling in C. elegans as a Bioanalytical Tool.

With chemical analysis, it is impossible to qualify and quantify the toxic potency of especially hydrophilic bioactive contaminants. In this study, we applied the nematode C. elegans as a model organism for detecting the toxic potency of whole influent wastewater samples.

The genetic architecture underlying body-size traits plasticity over different temperatures and developmental stages in Caenorhabditis elegans.

Most ectotherms obey the temperature-size rule, meaning they grow larger in a colder environment. This raises the question of how the interplay between genes and temperature affects the body size of ectotherms. Despite the growing body of literature on the physiological life-history and molecular genetic mechanism underlying the temperature-size rule, the overall genetic architecture orchestrating this complex phenotype is not yet fully understood.

Differential expression of genes in C. elegans reveals transcriptional responses to indirect-acting xenobiotic compounds and insensitivity to 2,3,7,8-tetrachlorodibenzodioxin.

Caenorhabditis elegans is a well-established model organism for toxicity testing of chemical substances. We recently demonstrated its potential for bioanalysis of the toxic potency of chemical contaminants in water. While many detoxification genes are homologues to those in mammalians, C.

Balancing Selection of the Intracellular Pathogen Response in Natural Populations.

Genetic variation in host populations may lead to differential viral susceptibilities. Here, we investigate the role of natural genetic variation in the Intracellular Pathogen Response (IPR), an important antiviral pathway in the model organism against Orsay virus (OrV). The IPR involves transcriptional activity of 80 genes including the genes.

Development of a transcription-based bioanalytical tool to quantify the toxic potencies of hydrophilic compounds in water using the nematode Caenorhabditis elegans.

Low concentrations of environmental contaminants can be difficult to detect with current analytical tools, yet they may pose a risk to human and environmental health. The development of bioanalytical tools can help to quantify toxic potencies of biologically active compounds even of hydrophilic contaminants that are hard to extract from water samples. In this study, we exposed the model organism Caenorhabditis elegans synchronized in larval stage L4 to hydrophilic compounds via the water phase and analyzed the effect on gene transcription abundance.

The genetics of gene expression in a Caenorhabditis elegans multiparental recombinant inbred line population.

Studying genetic variation of gene expression provides a powerful way to unravel the molecular components underlying complex traits. Expression quantitative trait locus (eQTL) studies have been performed in several different model species, yet most of these linkage studies have been based on the genetic segregation of two parental alleles. Recently, we developed a multiparental segregating population of 200 recombinant inbred lines (mpRILs) derived from four wild isolates (JU1511, JU1926, JU1931, and JU1941) in the nematode Caenorhabditis elegans.

Virus infection modulates male sexual behaviour in Caenorhabditis elegans.

Mating dynamics follow from natural selection on mate choice and individuals maximizing their reproductive success. Mate discrimination reveals itself by a plethora of behaviours and morphological characteristics, each of which can be affected by pathogens. A key question is how pathogens affect mate choice and outcrossing behaviour.

Transcriptional analysis of the response of C. elegans to ethanol exposure.

Ethanol-induced transcriptional changes underlie important physiological responses to ethanol that are likely to contribute to the addictive properties of the drug. We examined the transcriptional responses of Caenorhabditis elegans across a timecourse of ethanol exposure, between 30 min and 8 h, to determine what genes and genetic pathways are regulated in response to ethanol in this model. We found that short exposures to ethanol (up to 2 h) induced expression of metabolic enzymes involved in metabolizing ethanol and retinol, while longer exposure (8 h) had much more profound effects on the transcriptome.

Punctuated Loci on Chromosome IV Determine Natural Variation in Orsay Virus Susceptibility of Strains Bristol N2 and Hawaiian CB4856.

Host-pathogen interactions play a major role in evolutionary selection and shape natural genetic variation. The genetically distinct strains, Bristol N2 and Hawaiian CB4856, are differentially susceptible to the Orsay virus (OrV). Here, we report the dissection of the genetic architecture of susceptibility to OrV infection.

Dissecting the eQTL Micro-Architecture in .

The study of expression quantitative trait loci (eQTL) using natural variation in inbred populations has yielded detailed information about the transcriptional regulation of complex traits. Studies on eQTL using recombinant inbred lines (RILs) led to insights on and regulatory loci of transcript abundance. However, determining the underlying causal polymorphic genes or variants is difficult, but ultimately essential for the understanding of regulatory networks of complex traits.

Transcriptome resilience predicts thermotolerance in Caenorhabditis elegans.

Background: The detrimental effects of a short bout of stress can persist and potentially turn lethal, long after the return to normal conditions. Thermotolerance, which is the capacity of an organism to withstand relatively extreme temperatures, is influenced by the response during stress exposure, as well as the recovery process afterwards. While heat-shock response mechanisms have been studied intensively, predicting thermal tolerance remains a challenge.

Selection and gene flow shape niche-associated variation in pheromone response.

From quorum sensing in bacteria to pheromone signalling in social insects, chemical communication mediates interactions among individuals in local populations. In Caenorhabditis elegans, ascaroside pheromones can dictate local population density; high levels of pheromones inhibit the reproductive maturation of individuals. Little is known about how natural genetic diversity affects the pheromone responses of individuals from diverse habitats.

Genetic background modifies phenotypic and transcriptional responses in a C. elegans model of α-synuclein toxicity.

Background: Accumulation of protein aggregates are a major hallmark of progressive neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. Transgenic Caenorhabditis elegans nematodes expressing the human synaptic protein α-synuclein in body wall muscle show inclusions of aggregated protein, which affects similar genetic pathways as in humans. It is not however known how the effects of α-synuclein expression in C.

A multi-parent recombinant inbred line population of C. elegans allows identification of novel QTLs for complex life history traits.

Background: The nematode Caenorhabditis elegans has been extensively used to explore the relationships between complex traits, genotypes, and environments. Complex traits can vary across different genotypes of a species, and the genetic regulators of trait variation can be mapped on the genome using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) derived from genetically and phenotypically divergent parents. Most RILs have been derived from crossing two parents from globally distant locations.

Temporal dynamics of gene expression in heat-stressed Caenorhabditis elegans.

There is considerable insight into pathways and genes associated with heat-stress conditions. Most genes involved in stress response have been identified using mutant screens or gene knockdowns. Yet, there is limited understanding of the temporal dynamics of global gene expression in stressful environments.

Ras/MAPK Modifier Loci Revealed by eQTL in .

The oncogenic Ras/MAPK pathway is evolutionarily conserved across metazoans. Yet, almost all our knowledge on this pathway comes from studies using single genetic backgrounds, whereas mutational effects can be highly background dependent. Therefore, we lack insight in the interplay between genetic backgrounds and the Ras/MAPK-signaling pathway.

Contribution of trans regulatory eQTL to cryptic genetic variation in C. elegans.

Background: Cryptic genetic variation (CGV) is the hidden genetic variation that can be unlocked by perturbing normal conditions. CGV can drive the emergence of novel complex phenotypes through changes in gene expression. Although our theoretical understanding of CGV has thoroughly increased over the past decade, insight into polymorphic gene expression regulation underlying CGV is scarce.

Widespread genomic incompatibilities in Caenorhabditis elegans.

In the Bateson-Dobzhansky-Muller (BDM) model of speciation, incompatibilities emerge from the deleterious interactions between alleles that are neutral or advantageous in the original genetic backgrounds, i.e., negative epistatic effects.

Loss-of-function of β-catenin bar-1 slows development and activates the Wnt pathway in Caenorhabditis elegans.

C. elegans is extensively used to study the Wnt-pathway and most of the core-signalling components are known. Four β-catenins are important gene expression regulators in Wnt-signalling.

A heritable antiviral RNAi response limits Orsay virus infection in Caenorhabditis elegans N2.

Orsay virus (OrV) is the first virus known to be able to complete a full infection cycle in the model nematode species Caenorhabditis elegans. OrV is transmitted horizontally and its infection is limited by antiviral RNA interference (RNAi). However, we have no insight into the kinetics of OrV replication in C.

A rapid and massive gene expression shift marking adolescent transition in C. elegans.

Organismal development is the most dynamic period of the life cycle, yet we have only a rough understanding of the dynamics of gene expression during adolescent transition. Here we show that adolescence in Caenorhabditis elegans is characterized by a spectacular expression shift of conserved and highly polymorphic genes. Using a high resolution time series we found that in adolescent worms over 10,000 genes changed their expression.

Aging Uncouples Heritability and Expression-QTL in Caenorhabditis elegans.

The number and distribution of gene expression QTL (eQTL) represent the genetic architecture of many complex traits, including common human diseases. We previously reported that the heritable eQTL patterns are highly dynamic with age in an N2 × CB4856 recombinant inbred population of the nematode Caenorhabditis elegans. In particular, we showed that the number of eQTL decreased with age.