Search Results for: c elegans

Author: Cram, E.J.; Shang, H.; Schwarzbauer, J.E. Description: Cell migration is essential during embryonic development and tissue morphogenesis. During gonadogenesis in the nematode Caenorhabditis elegans, migration of the distal tip cells forms two U-shaped gonad arms. Malformation results if the distal tip cells stop prematurely or follow an aberrant path, and abnormalities are easily visualized in living nematodes. Here we describe the first comprehensive in vivo RNA interference screen for genes required for cell migration. In this non-biased screen, we systematically analyzed 16,758 RNA-interference depletion experiments by light microscopy and…

Author: Riddle, D.L.; Blumenthal, T.; Meyer, B.J.; Priess, J.R. Description: Why should one study a worm? This simple creature is one of several “model” organisms that together have provided tremendous insight into how all organisms are put together. It has become increasingly clear over the past two decades that knowledge from one organism, even one so simple as a worm, can provide tremendous power when connected with knowledge from other organisms. And because of the experimental accessibility of nematodes, knowledge about worms can come more quickly and cheaply than knowledge…

Author: White, J. G.; Southgate, E.; Thomson, J. N.; Brenner, S. Description: The structure and connectivity of the nervous system of the nematode Caenorhabditis elegans has been deduced from reconstructions of electron micrographs of serial sections. The hermaphrodite nervous system has a total complement of 302 neurons, which are arranged in an essentially invariant structure. Neurons with similar morphologies and connectivities have been grouped together into classes; there are 118 such classes. Neurons have simple morphologies with few, if any, branches. Processes from neurons run in defined positions within bundles…

Author: Klass, M. R. Description: At each molt a normal animal passes through “lethargus,” a stage in which feeding and locomotion are transiently arrested. In the dauerlarva stage, feeding is arrested indefinitely, and locomotion is markedly reduced. A simple quantitative assay, based on the exceptional resistance of dauerlarvae to sodium dodecyl sulfate (SDS), has been developed to study dauerlarva formation and its reversal. The SDS resistance of dauerlarvae requires both non-feeding and an especially impermeable cuticle. Dauerlarva formation can be efficiently induced by limiting the concentration of bacteria (the food…

Author: Cassada, R. C.; Russell, R. L. Description: In the postembryological development of the free-living nematode Caenorhabditis elegans, a morphologically recognizable, nongrowing stage, called the dauerlarva, may arise. Using synchronous populations and following growth and molting, it has been shown that the dauerlarva is formed by a facultative, reversible arrest at a specific point in the life cycle, the second of four cuticle molts, in response to external conditions. Subject headings: Animals; Environment; Feeding Behavior; Glucose; Larva; Mutation; Nematoda; Sodium Chloride; Sodium Dodecyl Sulfate; Temperature; Caenorhabditis elegans; C elegans; Dauerlarva Publication…

Author: Hirsh, D.; Oppenheim, D.; Klass, M. Description: A morphological study of the growth and the development of the reproductive system of the nematode Caenorhabditis elegans has been carried out. When the first stage larva hatches from the egg it contains four primordial gonadial cells. These cells proliferate and form the entire adult reproductive system, consisting of approximately 2500 nuclei, in 45 hr at 25°C. Several distinctive morphological featues of gonadogenesis and early embryogenesis that are recognizable in the compound microscope can be used to chart the development of the…

Author: Moerman, D.G.; Plurad, S.; Waterston, R.H.; Baillie, D.L. Description: Reversion analysis of mutants of unc-22 IV, a gene affecting muscle structure and function in Caenorhabditis elegans, led to the isolation of six extragenic dominant suppressors of the “twitching” phenotype of unc-22 mutants. All six suppressors are new alleles of unc-54 I, the major body wall myosin heavy chain gene. Homozygous suppressor strains are slow, stiff and have normal muscle structure, whereas previously identified unc-54 alleles confer flaccid paralysis and drastic reduction in thick filament number and organization. Placement of…