Search Results for: c elegans

Author: Boyd, W.A.; Cole, R.D.; Anderson, G.L.; Williams, P.L. Description: Caenorhabditis elegans, a nonparasitic soil nematode, was used to assess the combined effects of metal exposures and food availability on behavior. Movement was monitored using a computer tracking system after exposures to Cu, Pb, or Cd while feeding was measured as a change in optical density (deltaOD) of bacteria suspensions over the exposure period. After 24-h exposures at high and low bacteria concentrations, movement was decreased in a concentration-dependent fashion by Pb and Cd but feeding reductions were not directly…

Author: Biron, D.; Shibuya, M.; Gabel, C.; Wasserman, S.M.; Clark, D.A.; Brown, A.; Sengupta, P.; Samuel, A.D.T. Description: A memory of prior thermal experience governs Caenorhabditis elegans thermotactic behavior. On a spatial thermal gradient, C. elegans tracks isotherms near a remembered temperature we call the thermotactic set-point (T(S)). The T(S) corresponds to the previous cultivation temperature and can be reset by sustained exposure to a new temperature. The mechanisms underlying this behavioral plasticity are unknown, partly because sensory and experience-dependent components of thermotactic behavior have been difficult to separate. Using…

Author: Baylis, H.A.; Vazquez-Manrique, R.P. Description: BACKGROUND: The nematode, Caenorhabditis elegans, is an established model system that is particularly well suited to genetic analysis. C. elegans is easily manipulated and we have an in depth knowledge of many aspects of its biology. Thus, it is an attractive system in which to pursue integrated studies of signalling pathways. C. elegans has a complement of calcium signalling molecules similar to that of other animals. SCOPE OF REVIEW: We focus on IP3 signalling. We describe how forward and reverse genetic approaches, including RNAi,…

Author: Lee, S.-J., Murphy, C. T., & Kenyon, C. Description: Many studies have addressed the effect of dietary glycemic index on obesity and diabetes, but little is known about its effect on life span itself. We found that adding a small amount of glucose to the medium (2%) shortened the life span of C. elegans by inhibiting the activities of life span-extending transcription factors that are also inhibited by insulin signaling: the FOXO family member DAF-16 and the heat shock factor HSF-1. This effect involved the downregulation of an aquaporin…

Author: Baylis, H.A.; Furuichi, T.; Yoshikawa, F.; Mikoshiba, K.; Sattelle, D.B. Description: Inositol 1,4,5-trisphosphate (InsP3) activates receptors (InsP3Rs) that mediate intracellular Ca(2+ )release, thereby modulating intracellular calcium signals and regulating important aspects of cellular physiology and gene expression. To further our understanding of InsP3Rs we have characterised InsP3Rs and the InsP3R gene, itr-1, from the model organism Caenorhabditis elegans. cDNAs encoding InsP3Rs were cloned enabling us to: (a) identify three putative transcription start sites that result in alternative mRNA 5′ ends: (b) detect alternative splicing at three sites and: (c)…

Author: Anderson, J.L.; Albergotti, L.; Proulx, S.; Peden, C.; Huey, R.B.; Phillips, P.C. Description: The preferred body temperature of ectotherms is typically inferred from the observed distribution of body temperatures in a laboratory thermal gradient. For very small organisms, however, that observed distribution might misrepresent true thermal preferences. Tiny ectotherms have limited thermal inertia, and so their body temperature and speed of movement will vary with their position along the gradient. In order to separate the direct effects of body temperature on movement from actual preference behavior on a thermal…

Author: Anderson, J.L.; Albergotti, L.; Ellebracht, B.; Huey, R.B.; Phillips, P.C. Description: BACKGROUND: A central premise of physiological ecology is that an animal’s preferred body temperature should correspond closely with the temperature maximizing performance and Darwinian fitness. Testing this co-adaptational hypothesis has been problematic for several reasons. First, reproductive fitness is the appropriate measure, but is difficult to measure in most animals. Second, no single fitness measure applies to all demographic situations, complicating interpretations. Here we test the co-adaptation hypothesis by studying an organism (Caenorhabditis elegans) in which both fitness…

Author: Kampkotter, A.; Timpel, C.; Zurawski, R.F.; Ruhl, S.; Chovolou, Y.; Proksch, P.; Watjen, W. Description: The health beneficial effects of a diet rich in fruits and vegetables are, at least in part, attributed to polyphenols that are present in many herbal edibles. Although many in vitro studies revealed a striking variety of biochemical and pharmacological properties data about the beneficial effects of polyphenols in whole organisms, especially with respect to ageing, are quite limited. We used the well established model organism Caenorhabditis elegans to elucidate the protective effects of…

Author: Ventura, Natascia; Rea, Shane L. Description: In humans, well over one hundred diseases have been linked to mitochondrial dysfunction and many of these are associated with neurodegeneration. At the root of most of these diseases lay ineffectual energy production, caused either by direct or indirect disruption to components of the mitochondrial electron transport chain. It is surprising then to learn that, in the nematode Caenorhabditis elegans, a collection of mutants which share disruptions in some of the same genes that cause mitochondrial pathogenesis in humans are in fact long-lived….

Author: Matus, David Q.; Lohmer, Lauren L.; Kelley, Laura C.; Schindler, Adam J.; Kohrman, Abraham Q.; Barkoulas, Michalis; Zhang, Wan; Chi, Qiuyi; Sherwood, David R. Description: Despite critical roles in development and cancer, the mechanisms that specify invasive cellular behavior are poorly understood. Through a screen of transcription factors in Caenorhabditis elegans, we identified G1 cell-cycle arrest as a precisely regulated requirement of the anchor cell (AC) invasion program. We show that the nuclear receptor nhr-67/tlx directs the AC into G1 arrest in part through regulation of the cyclin-dependent kinase…