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J Neurobiol,
1993]
Mutations causing a touch-insensitive phenotype in the nematode Caenorhabditis elegans have been the basis of studies on the specification of neuronal cell fate, inherited neurodegeneration, and the molecular nature of mechanosensory transduction. (C) 1993 John Wiley & sons, Inc.
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Human Genome News,
1999]
For the first time, scientists have the nearly complete genetic instructions for an animal that, like humans, has a nervous system, digests food, and reproduces sexually. The 97-million-base genome of the tiny roundworm Caenorhabditis elegans was deciphered by an international team led by Robert Waterston and John Sulston. The work was reported in a special issue of the journal Science (December 11, 1998) that featured six articles describing the history and significance of the accomplishment and some early sequence-analysis results.
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Science,
1994]
In 1967, Sydney Brenner isolated the first behavioral mutants of the nematode Caenorhabditis elegans, and in 1970, John White began the systematic reconstruction of its nervous system. This dual approach of genetics coupled with detailed morphological analysis, now enhanced by the tools of molecular biology and electrophysiology, still dominates the study of the function and development of the C. elegans nervous system. Although Brenner's vision of a comprehensive understanding of this simple animal has taken time to mature, findings of the past few years indicate that the tree is bearing fruit.
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Parasitol Today,
1990]
Many aspects of the biology of kinetoplastids are unique, so it is surprising that they share with nematodes an unusual post-transcriptional process called trans-splicing. During this process, a small conserved RNA sequence is added to the 5' non-translated ends of transcribed RNAs of protein-encoding genes. Trypanosomes and nematodes are the only organisms to date in which these sequences have been described, and the biological significance of trans-splicing remains a mystery but may be of wider occurrence in invertebrates. In this review, John Donelson and Wenlin Zeng compare the process in nematodes and trypanosomes and speculate on its raison d'etre.
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J Pathol,
2009]
Virtually every tissue of the adult organism maintains a population of putatively slowly-cycling stem cells that maintain homeostasis of the tissue and respond to injury when challenged. These cells are regulated and supported by the surrounding microenvironment, referred to as the stem cell ''niche''. The niche includes all cellular and non-cellular components that interact in order to control the adult stem cell, and these interactions can often be broken down into one of two major mechanistic categories-physical contact and diffusible factors. The niche has been studied directly and indirectly in a number of adult stem cell systems. Herein, we will first focus on the most well-understood niches supporting the germline stem cells in the lower organisms Caenorhabditis elegans and Drosophila melanogaster before concentrating on the more complex, less well-understood mammalian niches supporting the neural, epidermal, haematopoietic and intestinal stem cells. Copyright (c) 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Studies of History & Philosophy of Science,
1998]
In 1963, just a year after the researchers of the Medical Research Council (MRC) Unit of Molecular Biology in Cambridge, joined by some other research groups, has moved from various scattered and makeshift buildings in the courtyard of the Physics Department to a lavishly funded four-storey laboratory, B. Lush, the Principal Medical Officer of the MRC, came to inquire about their plans for future expansion. He indicated that the MRC wished to build the laboratory up to what the principal researchers considered its 'final size' until their retirement, which meant planning ahead for at least 15 years. This surprising move was doubtless prompted by the recent award of the Nobel Prize to three members of the laboratory, Max Perutz, John Kendrew and Francis Crick, for their work on the molecular structure of proteins and nucleic acids. The triple award had propelled the new Laboratory of Molecular Biology into the limelight, and the MRC was interested in securing optimal research conditions for this prestigious group of researchers.
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J Pathol,
2009]
Stem cells are expected to play a key role in the development and maintenance of organisms, and hold great therapeutic promises. However, a number of questions must be answered to achieve an understanding of stem cells and put them to use. Here I review some of these questions, and how they relate to the model system provided by the Caenorhabditis elegans germ line, which is exceptional in its thorough genetic characterization and experimental accessibility under in vivo conditions. A fundamental question is how to define a stem cell; different definitions can be adopted that capture different features of interest. In the C. elegans germ line, stem cells can be defined by cell lineage or by cell commitment (''commitment'' must itself be carefully defined). These definitions are associated with two other important questions about stem cells: their functions (which must be addressed following a systems approach, based on an evolutionary perspective) and their regulation. I review possible functions and their evolutionary groundings, including genome maintenance and powerful regulation of cell proliferation and differentiation, and possible regulatory mechanisms, including asymmetrical division and control of transit amplification by a developmental timer. I draw parallels between Drosophila and C. elegans germline stem cells; such parallels raise intriguing questions about Drosophila stem cells. I conclude by showing that the C. elegans germ line bears similarities with a number of other stem cell systems, which underscores its relevance to the understanding of stem cells. Copyright (c) 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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J Appl Toxicol,
2016]
Caenorhabditis elegans is a small nematode that can be maintained at low cost and handled using standard in vitro techniques. Unlike toxicity testing using cell cultures, C. elegans toxicity assays provide data from a whole animal with intact and metabolically active digestive, reproductive, endocrine, sensory and neuromuscular systems. Toxicity ranking screens in C. elegans have repeatedly been shown to be as predictive of rat LD50 ranking as mouse LD50 ranking. Additionally, many instances of conservation of mode of toxic action have been noted between C. elegans and mammals. These consistent correlations make the case for inclusion of C. elegans assays in early safety testing and as one component in tiered or integrated toxicity testing strategies, but do not indicate that nematodes alone can replace data from mammals for hazard evaluation. As with cell cultures, good C. elegans culture practice (GCeCP) is essential for reliable results. This article reviews C. elegans use in various toxicity assays, the C. elegans model's strengths and limitations for use in predictive toxicology, and GCeCP. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Journal of Applied Toxicology published by John Wiley & Sons Ltd.
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Science,
2004]
I'm one of the 2000 or so worm people who study the tiny nematode Caenorhabditis elegans. When we are asked by an outsider why we play with worms, our much-practiced answer goes something like this: In the
mid-1960s, Sydney Brenner chose C. elegans as a model organism for elucidating animal development and behavior because of the roundworm's cellular simplicity and advantages for genetic studies. The analysis of mutants helps us learn what the nonmutant versions of genes do. We know the location and lineage of every cell in an adult C. elegans as well as the wiring of all the worm's 302 neurons, down to the last synapse. C. elegans was the first multicellular organism to have its DNA completely sequenced (1), and many of its genes resemble those of humans and do similar jobs. The importance of such research was highlighted when Brenner, John Sulston, and Bob Horvitz were awarded the 2002 Nobel Prize in physiology or medicine for their worm work.
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International Journal of Developmental Biology,
1998]
Pleiotropy , a situation in which a single gene influences multiple phenotypic tra its, can arise in a variety of ways. This paper discusses possible underlying mechanisms and proposes a classification of the various phenomena involved.