Search Results for: c elegans

Author: Schafer, William R. Description: C. elegans hermaphrodites are self-fertile, and their rate and temporal pattern of egg-laying are modulated by diverse environmental cues. Egg-laying behavior has served as an important phenotypic assay for the genetic dissection of neuronal signal transduction mechanisms. This chapter reviews our current understanding of the neuronal and neurochemical mechanisms underlying the control of egg-laying in C. elegans. The roles of specific neurons in the egg-laying motor circuit, which release multiple neurotransmitters affecting distinct parameters of egg-laying muscle activity, and the possible mechanisms for sensory control…

Author: Kobayashi, Yosuke; Furukawa-Hibi, Yoko; Chen, Chen; Horio, Yoshiyuki; Isobe, Kenichi; Ikeda, Kyoji; Motoyama, Noboru Description: Forkhead transcription factor, DAF-16, regulates genes that contribute both to longevity and resistance to various stresses in C. elegans. We and others have reported that members of the FOXO, mammalian homologs of DAF-16, also regulate genes related to stress resistance, such as GADD45. The NAD-dependent protein deacetylase, SIR2, is required for life span extension in yeast induced by caloric restriction, which also increases longevity in a wide variety of other organisms, including mammals. Sir2.1,…

Author: Barr, M. M., Garcia, L. R. Description: Caenorhabditis elegans male mating provides an excellent opportunity to determine how sensory perception regulates behavior and motor programs. The male-specific nervous system and muscles are superimposed over the general nervous system and musculature. Genetic screens and genomic approaches have identified male-specific and male-enriched genes as well as non-sex specific molecules specialized for mating sub-behaviors. In this chapter, we discuss the cellular, genetic, and molecular basis for male mating behavior. Subject headings: Animals; Caenorhabditis elegans/anatomy & histology; Caenorhabditis elegans/physiology; Ejaculation; Female; Male; Sex…

Author: Peters, J. M.; McKay, R. M.; McKay, J. P.; Graff, J. M. Description: The Wnt signalling cascade is essential for the development of both invertebrates and vertebrates, and is altered during tumorigenesis. Although a general framework for Wnt signalling has been elucidated, not all of the components have been identified. Here we describe a serine kinase, casein kinase I (CKI), which was isolated by expression cloning in Xenopus embryos. CKI reproduces several properties of Wnt signals, including generation of complete dorsal axes, stabilization of beta-catenin and induction of genes…

Author: Muller, Bruno; Grossniklaus, Ueli Description: Much of our knowledge on heredity, development, physiology and the underlying cellular and molecular processes is derived from the studies of model, or reference, organisms. Despite the great variety of life, a common base of shared principles could be extracted by studying a few life forms, selected based on their amenability to experimental studies. Very briefly, the origins of a few model organisms are described, including E. coli, yeast, C. elegans, Drosophila, Xenopus, zebrafish, mouse, maize and Arabidopsis. These model organisms were chosen because…

Author: Perez, V.I.; Bokov, A.; Van Remmen, H.; Mele, J.; Ran, Q.; Ikeno, Y.; Richardson, A. Description: Currently, the oxidative stress (or free radical) theory of aging is the most popular explanation of how aging occurs at the molecular level. While data from studies in invertebrates (e.g., C. elegans and Drosophila) and rodents show a correlation between increased lifespan and resistance to oxidative stress (and in some cases reduced oxidative damage to macromolecules), direct evidence showing that alterations in oxidative damage/stress play a role in aging are limited to a…

Author: Driscoll, M.; Gerstbrein, B. Description: If invertebrate neurons are injured by hostile environments or aberrant proteins they die much like human neurons, indicating that the powerful advantages of invertebrate molecular genetics might be successfully used for testing specific hypotheses about human neurological diseases, for drug discovery and for non-biased screens for suppressors and enhancers of neurodegeneration. Recent molecular dissection of the genetic requirements for hypoxia, excitotoxicity and death in models of Alzheimer disease, polyglutamine-expansion disorders, Parkinson disease and more, is providing mechanistic insights into neurotoxicity and suggesting new therapeutic…