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[
1987]
One way to gain an understanding of any biological process is through the use of mutant analysis and selective breeding to generate stocks which have genetic alterations in that process. We have taken just this approach in the analysis of aging...
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[
1969]
In order to study properly the nutrition and culture of nematodes, it is desirable to establish the organisms in axenic culture. Only in this way can the metabolic abilities of the nematodes be separated from those of coexisting and interacting organisms. One may settle for a mono-axenic culture, but the best way to attain this is to obtain axenic nematodes and then add the second organism or tissue, for example, alfalfa callus tissue for plant parasitic nematodes (Krusberg, 1961). This chapter will devote itself, in the main, to recent work on the culture and nutrition of nematodes, free-living and parasitic, and will refer only in passing to work already thoroughly reviewed (Dougherty et al., 1959; Nicholas, et al., 1959; Dougherty, 1960).
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[
1960]
For the purpose of the present chapter the noun 'cultivation' is to be taken as the maintenance, in the laboratory, of a population of organisms belonging to a desired species through successive generations and subcultures over a prolonged period of time (weeks, months, or years). This is a deliberate restriction of the term. The noun 'culture' is most aptly used for a population within a circumscribed vessel or container (test-tube, Petri dish, U.S. Bureau of Plant Industry watch glass, etc.); it is also used in a looser, more general way (as "in culture") to cover conditions of substantial growth whether or not leading to cultivation in the strict sense
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[
Methods Cell Biol,
1995]
One way to study cell function is to eliminate the cell and observe subsequent developmental or behavioral abnormalities in the animal. In Caenorhabditis elegans, this is usually accomplished by killing individual cells or groups of cells with a laser microbeam. Laser killing has been used to determine the functions of many mature cell types, including neurons involved in locomotion, feeding, mechanosensation, and chemosensation. These studies have been practical because only a few cell types appear to be absolutely required for viability. Laser ablation can also be sued to ask how cells interact during development. Signaling and inductive interactions between cells can be examined by removing one cell and observing the development of the remaining cells...
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Sorrentino V, Deplancke B, Ouhmad T, Cornaglia M, Gijs MA, Auwerx J, Williams EG, Krishnamani G, Frochaux MV, Nicolet-Dit-Felix AA, Lin T, Mouchiroud L
[
Curr Protoc Neurosci,
2016]
Phenotyping strategies in simple model organisms such as D. melanogaster and C. elegans are often broadly limited to growth, aging, and fitness. Recently, a number of physical setups and video tracking software suites have been developed to allow for accurate, quantitative, and high-throughput analysis of movement in flies and worms. However, many of these systems require precise experimental setups and/or fixed recording formats. We report here an update to the Parallel Worm Tracker software, which we termed the Movement Tracker. The Movement Tracker allows variable experimental setups to provide cross-platform automated processing of a variety of movement characteristics in both worms and flies and permits the use of simple physical setups that can be readily implemented in any laboratory. This software allows high-throughput processing capabilities and high levels of flexibility in video analysis, providing quantitative movement data on C. elegans and D. melanogaster in a variety of different conditions. 2016 by John Wiley and Sons, Inc.
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[
1988]
The development of a multicellular organism from a single-celled egg involves the coordinated control of many cells and tissues. How are cells specified to develop as one cell type rather than another, in one position rather than another, and at one time rather than another? What is the molecular basis of the spatial and temporal cues necessary to direct development of the organism? The information for this developmental feat is stored in the egg-either in its genome or in products of the maternal genome contributed to that cell. Developmental genetics provides a powerful way to investigate that information. The nematode, Caenorhabditis elegans, has proven to be an excellent model organism for analysis of the genes that control development...
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[
Methods Mol Biol,
2011]
Quantitative proteomics aims to identify and quantify proteins in cells or organisms that have been obtained from different biological origin (e.g., "healthy vs. diseased"), that have received different treatments, or that have different genetic backgrounds. Protein expression levels can be quantified by labeling proteins with stable isotopes, followed by mass spectrometric analysis. Stable isotopes can be introduced in vitro by reacting proteins or peptides with isotope-coded reagents (e.g., iTRAQ, reductive methylation). A preferred way, however, is the metabolic incorporation of heavy isotopes into cells or organisms by providing the label, in the form of amino acids (such as in SILAC) or salts, in the growth media. The advantage of in vivo labeling is that it does not suffer from side reactions or incomplete labeling that might occur in chemical derivatization. In addition, metabolic labeling occurs at the earliest possible moment in the sample preparation process, thereby minimizing the error in quantitation. Labeling with the heavy stable isotope of nitrogen (i.e., (15)N) provides an efficient way for accurate protein quantitation. Where the application of SILAC is mostly restricted to cell culture, (15)N labeling can be used for micro-organisms as well as a number of higher (multicellular) organisms. The most prominent examples of the latter are Caenorhabditis elegans and Drosophila (fruit fly), two important model organisms for a range of regulatory processes underlying developmental biology. Here we describe in detail the labeling with (15)N atoms, with a particular focus on fruit flies and C. elegans. We also describe methods for the identification and quantitation of (15)N-labeled proteins by mass spectrometry and bioinformatic analysis.
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[
1975]
Studies in behaviour genetics have covered a wide field: motivation, development, sensory capacities, intelligence, learning, evolution, neuromorphology and neurochemistry have all been approached using genetic techniques, and there are probably others. Whilst it is at present impossible to construct any unities one must accept that many such studies have as their common aim one of the most fundamental problems in biology: how is behavioral potential encoded in genetic terms and expressed in the course of development? The relative enormity of this problem is often matched by its inaccessibilty. It cannot be claimed that there is any agreed view of the way forward and much of the work has frankly to be opportunistic-seizing on some favourable material or a useful new analytical technique to gain a limited objective. Consequently, behaviour genetics often presents a confusing picture of numerous disjointed studies, with
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[
WormBook,
2005]
Alternative splicing is a common mechanism for the generation of multiple isoforms of proteins. It can function to expand the proteome of an organism and can serve as a way to turn off gene expression post-transcriptionally. This review focuses on splicing and its regulation in C. elegans. The fully-sequenced C. elegans genome combined with its elegant genetics offers unique advantages for exploring alternative splicing regulation in metazoans. The topics covered in this review include constitutive splicing factors, identification of alternatively spliced genes, examples of alternative splicing in C. elegans, and alternative splicing regulation. Key genes whose regulated alternative splicing are reviewed include
let-2 ,
unc-32 ,
unc-52 ,
egl-15 and
xol-1 . Factors involved in alternative splicing that are discussed include
mec-8 ,
smu-1 ,
smu-2 ,
fox-1 ,
exc-7 and
unc-75 .
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[
WormBook,
2007]
Great inroads into the understanding of aging have been made using C. elegans as a model system. Several genes have been identified that, when mutated, can extend lifespan. Yet, much about aging remains a mystery, and new technologies that allow the simultaneous assay of expression levels of thousands of genes have been applied to the question of how and why aging might occur. With correct experimental design and statistical analysis, differential gene expression between two or more populations can be obtained with high confidence. The ability to survey the entire genome in an unbiased way is a great asset for the study of complex biological phenomena such as aging. Aging undoubtedly involves changes in multiple genes involved in multiple processes, some of which may not yet be known. Gene expression profiling of wild type aging, and of strains with increased life spans, has provided some insight into potential mechanisms, and more can be expected in the future.