Dissection of C. elegans behavioral genetics in 3-D environments.
Ontology highlight
ABSTRACT:
SUBMITTER: Kwon N
PROVIDER: S-EPMC4424945 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Thousands of behavioral mutants of Caenorhabditis elegans have been studied. I suggest a set of criteria by which some genes important in the evolution of behavior might be recognized, and identify neuropeptide signaling pathways as candidates.
| S-EPMC2882361 | biostudies-literature
Project description:The molecular mechanisms that enable multicellular organisms to sense and modulate their responses to hyperosmotic environments are poorly understood. Here, we employ Caenorhabditis elegans to characterize the response of a multicellular organism to osmotic stress and establish a genetic screen to isolate mutants that are osmotic stress resistant (OSR). In this study, we describe the cloning of a novel gene, osr-1, and demonstrate that it regulates osmosensation, adaptation, and survival in hyperosmotic environments. Whereas wild-type animals exposed to hyperosmotic conditions rapidly lose body volume, motility, and viability, osr-1(rm1) mutant animals maintain normal body volume, motility, and viability even upon chronic exposures to high osmolarity environments. In addition, osr-1(rm1) animals are specifically resistant to osmotic stress and are distinct from previously characterized osmotic avoidance defective (OSM) and general stress resistance age-1(hx546) mutants. OSR-1 is expressed in the hypodermis and intestine, and expression of OSR-1 in hypodermal cells rescues the osr-1(rm1) phenotypes. Genetic epistasis analysis indicates that OSR-1 regulates survival under osmotic stress via CaMKII and a conserved p38 MAP kinase signaling cascade and regulates osmotic avoidance and resistance to acute dehydration likely by distinct mechanisms. We suggest that OSR-1 plays a central role in integrating stress detection and adaptation responses by invoking multiple signaling pathways to promote survival under hyperosmotic environments.
| S-EPMC1470864 | biostudies-other
Project description:To quantitatively understand chemosensory behaviors, it is desirable to present many animals with repeatable, well-defined chemical stimuli. To that end, we describe a microfluidic system to analyze Caenorhabditis elegans behavior in defined temporal and spatial stimulus patterns. A 2 cm × 2 cm structured arena allowed C. elegans to perform crawling locomotion in a controlled liquid environment. We characterized behavioral responses to attractive odors with three stimulus patterns: temporal pulses, spatial stripes and a linear concentration gradient, all delivered in the fluid phase to eliminate variability associated with air-fluid transitions. Different stimulus configurations preferentially revealed turning dynamics in a biased random walk, directed orientation into an odor stripe and speed regulation by odor. We identified both expected and unexpected responses in wild-type worms and sensory mutants by quantifying dozens of behavioral parameters. The devices are inexpensive, easy to fabricate, reusable and suitable for delivering any liquid-borne stimulus.
| S-EPMC3152576 | biostudies-literature
Project description:We describe the scientific enterprise at the intersection of evolutionary psychology and behavioral genetics-a field that could be termed Evolutionary Behavioral Genetics-and how modern genetic data is revolutionizing our ability to test questions in this field. We first explain how genetically informative data and designs can be used to investigate questions about the evolution of human behavior, and describe some of the findings arising from these approaches. Second, we explain how evolutionary theory can be applied to the investigation of behavioral genetic variation. We give examples of how new data and methods provide insight into the genetic architecture of behavioral variation and what this tells us about the evolutionary processes that acted on the underlying causal genetic variants.
| S-EPMC4288764 | biostudies-literature
Project description:We analyze mathematical models to examine how the genetic basis of fitness affects the persistence of a population suddenly encountering a harsh environment where it would go extinct without evolution. The results are relevant for novel introductions and for an established population whose existence is threatened by a sudden change in the environment. The models span a range of genetic assumptions, including identical loci that contribute to absolute fitness, a two-locus quantitative genetic model with nonidentical loci, and a model with major and minor genes affecting a quantitative trait. We find as a general (though not universal) pattern that prospects for persistence narrow as more loci contribute to fitness, in effect because selection per locus is increasingly weakened with more loci, which can even overwhelm any initial enhancement of fitness that adding loci might provide. When loci contribute unequally to fitness, genes of small effect can significantly reduce extinction risk. Indeed, major and minor genes can interact synergistically to reduce the time needed to evolve growth. Such interactions can also increase vulnerability to extinction, depending not just on how genes interact but also on the initial genetic structure of the introduced, or newly invaded, population.
| S-EPMC3352474 | biostudies-literature
Project description:This review summarizes the proceedings of a symposium presented at the "Alcoholism and Stress: A Framework for Future Treatment Strategies" conference held in Volterra, Italy on May 9-12, 2017. Psychiatric diseases, including alcohol-use disorders (AUDs), are influenced through complex interactions of genes, neurobiological pathways, and environmental influences. A better understanding of the common neurobiological mechanisms underlying an AUD necessitates an integrative approach, involving a systematic assessment of diverse species and phenotype measures. As part of the World Congress on Stress and Alcoholism, this symposium provided a detailed account of current strategies to identify mechanisms underlying the development and progression of AUDs. Dr. Sean Farris discussed the integration and organization of transcriptome and postmortem human brain data to identify brain regional- and cell type-specific differences related to excessive alcohol consumption that are conserved across species. Dr. Brien Riley presented the results of a genome-wide association study of DSM-IV alcohol dependence; although replication of genetic associations with alcohol phenotypes in humans remains challenging, model organism studies show that COL6A3, KLF12, and RYR3 affect behavioral responses to ethanol, and provide substantial evidence for their role in human alcohol-related traits. Dr. Rob Williams expanded upon the systematic characterization of extensive genetic-genomic resources for quantifying and clarifying phenotypes across species that are relevant to precision medicine in human disease. The symposium concluded with Dr. Robert Hitzemann's description of transcriptome studies in a mouse model selectively bred for high alcohol ("binge-like") consumption and a non-human primate model of long-term alcohol consumption. Together, the different components of this session provided an overview of systems-based approaches that are pioneering the experimental prioritization and validation of novel genes and gene networks linked with a range of behavioral phenotypes associated with stress and AUDs.
| S-EPMC6309876 | biostudies-literature
Project description:In most animals, the brain makes behavioral decisions that are transmitted by descending neurons to the nerve cord circuitry that produces behaviors. In insects, only a few descending neurons have been associated with specific behaviors. To explore how descending neurons control an insect's movements, we developed a novel method to systematically assay the behavioral effects of activating individual neurons on freely behaving terrestrial D. melanogaster. We calculated a two-dimensional representation of the entire behavior space explored by these flies, and we associated descending neurons with specific behaviors by identifying regions of this space that were visited with increased frequency during optogenetic activation. Applying this approach across a large collection of descending neurons, we found that (1) activation of most of the descending neurons drove stereotyped behaviors, (2) in many cases multiple descending neurons activated similar behaviors, and (3) optogenetically activated behaviors were often dependent on the behavioral state prior to activation.
| S-EPMC6031430 | biostudies-literature
Project description:Cybersecurity (CS) is a contemporary field for research and applied study of a range of aspects from across multiple disciplines. A cybersecurity expert has an in-depth knowledge of technology but is often also recognized for the ability to view technology in a non-standard way. This paper explores how CS specialists are both a combination of professional computing-based skills and genetically encoded traits. Almost every human behavioral trait is a result of many genome variants in action altogether with environmental factors. The review focuses on contextualizing the behavior genetics aspects in the application of cybersecurity. It reconsiders methods that help to identify aspects of human behavior from the genetic information. And stress is an illustrative factor to start the discussion within the community on what methodology should be used in an ethical way to approach those questions. CS positions are considered stressful due to the complexity of the domain and the social impact it can have in cases of failure. An individual risk profile could be created combining known genome variants linked to a trait of particular behavior using a special biostatistical approach such as a polygenic score. These revised advancements bring challenging possibilities in the applications of human behavior genetics and CS.
| S-EPMC8614761 | biostudies-literature
Project description:Genomic imprinting results in parent-of-origin-dependent monoallelic expression of selected genes. Although their importance in development and physiology is recognized, few imprinted genes have been investigated for their effects on brain function. Gnas is a complex imprinted locus whose gene products are involved in early postnatal adaptations and neuroendocrine functions. Gnas encodes the stimulatory G-protein subunit Gsalpha and two other imprinted protein-coding transcripts. Of these, the Nesp transcript, expressed exclusively from the maternal allele, codes for neuroendocrine secretory protein 55 (Nesp55), a chromogranin-like polypeptide associated with the constitutive secretory pathway but with an unknown function. Nesp is expressed in restricted brain nuclei, suggesting an involvement in specific behaviors. We have generated a knockout of Nesp55 in mice. Nesp55-deficient mice develop normally, excluding a role of this protein in the severe postnatal effects associated with imprinting of the Gnas cluster. Behavioral analysis of adult Nesp55 mutants revealed, in three separate tasks, abnormal reactivity to novel environments independent of general locomotor activity and anxiety. This phenotype may be related to prominent Nesp55 expression in the noradrenergic locus coeruleus. These results indicate a role of maternally expressed Nesp55 in controlling exploratory behavior and are the first demonstration that imprinted genes affect such a fundamental behavior.
| S-EPMC1069615 | biostudies-literature
Project description:The large post-reproductive life span reported for the free-living hermaphroditic nematode, Caenorhabditis elegans, which lives for about 10 days after its 5-day period of self-reproduction, seems at odds with evolutionary theory. Species with long post-reproductive life spans such as mammals are sometimes explained by a need for parental care or transfer of information. This does not seem a suitable explanation for C elegans. Previous reports have shown that C elegans can regain fertility when mated after the self-fertile period but did not report the functional limits. Here, we report the functional life span of the C elegans germ line when mating with males. We show that C elegans can regain fertility late in life (significantly later than in previous reports) and that the end of this period corresponds quite well to its 3-week total life span. Genetic analysis reveals that late-life fertility is controlled by conserved pathways involved with aging and dietary restriction.
| S-EPMC3148761 | biostudies-literature