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Int J Parasitol,
2001]
The future direction of post-genomic nematode parasitology should focus on the function of the genes that are defined by large-scale expressed sequence tag sequencing and on broader questions about the genetic basis of parasitism. Functional characterisation will require the application of high throughput technologies that have been developed in other fields, including genome mapping strategies and DNA microarray analysis. These will be greatly aided by the development and application of appropriate model organisms. It is: crucial that the field make the transition from a narrow focus on one or a few genes at a time to a focus on whole genomes in order to fully realise the potential of the expressed sequence tag and other genomic projects currently under way.
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Methods,
2016]
The localization of a protein is intrinsically linked to its role in the structural and functional organization of the cell. Advances in transgenic technology have streamlined the use of protein localization as a function discovery tool. Here we review the use of large genomic DNA constructs such as bacterial artificial chromosomes as a transgenic platform for systematic tag-based protein function exploration.
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Trends in Parasitology,
2005]
Expressed sequence tag projects have currently produced over 400 000 partial gene sequences from more than 30 nematode species and the full genomic sequences of selected nematodes are being determined. In addition, functional analyses in the model nematode Caenorhabditis elegans have addressed the role of almost all genes predicted by the genome sequence. This recent explosion in the amount of available nematode DNA sequences, coupled with new gene function data, provides an unprecedented opportunity to identify pre-validated drug targets through efficient mining of nematode genomic databases. This article describes the various information sources available and strategies that can expedite this process.
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Wiley Interdiscip Rev Dev Biol,
2012]
Myogenesis has proved to be a powerful paradigm for understanding cell fate specification and differentiation in many model organisms. Studies of somatic bodywall muscle (BWM) development in Caenorhabditis elegans allow us to define, with single cell resolution, the distinct hierarchies of transcriptional regulators needed for myogenesis throughout development. Although all 95 BWM cells appear uniform after differentiation, there are several different regulatory cascades employed embryonically and post-embryonically. These, in turn, are integrated into multiple extrinsic cell signaling events. The convergence of these different pathways on the key nodal point, that is the activation of the core muscle module, commits individual cells to myogenesis. Comparisons of myogenesis between C. elegans and other model systems provide insights into the evolution of contractile cell types, demonstrating the conservation of regulatory schemes for muscles throughout the animal kingdom.
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WormBook,
2006]
The C. elegans embryo is a powerful model system for studying the mechanics of metazoan cell division. Its primary advantage is that the architecture of the syncytial gonad makes it possible to use RNAi to generate oocytes whose cytoplasm is reproducibly (typically > 95%) depleted of targeted essential gene products via a process that does not depend exclusively on intrinsic protein turnover. The depleted oocytes can then be analyzed as they attempt their first mitotic division following fertilization. Here we outline the characteristics that contribute to the usefulness of the C. elegans embryo for cell division studies. We provide a timeline for the first embryonic mitosis and highlight some of its key features. We also summarize some of the recent discoveries made using this system, particularly in the areas of nuclear envelope assembly/ dissassembly, centrosome dynamics, formation of the mitotic spindle, kinetochore assembly, chromosome segregation, and cytokinesis.
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Parasitology,
1999]
The initiation of genome projects on helminths of medical importance promises to yield new drug targets and vaccine candidates in unprecedented numbers. In order to exploit this emerging data it is essential that the user community is aware of the scope and quality of data available, and that the genome projects provide analyses of the raw data to highlight potential genes of interest. Core bioinformatics support for the parasite genome projects has promoted these approaches. In the Brugia genome project, a combination of expressed sequence tag sequencing from multiple DNA libraries representing the complete filarial nematode lifecycle, and comparative analysis of the sequence dataset, particularly using the complete genome sequence of the model nematode C. elegans, has proved very effective in gene discovery.
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Environmental Toxicology and Chemistry,
1999]
The nematode Caenorhabditis elegans (Maupas) was exposed in a sediment bioassay to 26 different unpolluted freshwater sediments varying in particle size distribution (2.5-18% clay, 25.7-68.2% silt, 18.7-70.9% sand) and organic content (2.5-77.1%). We examined the variation of the test endpoints body length, eggs per worm, and percentage of gravid worms. Caenorhabditis elegans tolerated all investigated sediments, with at least 80% (total mean 96.6%) of the worms reaching the stage of reproductive adults. Variation in body length was small (total mean 1,235 +/- 97.8 mu m), but significant differences among the various sediments were found. We found a weak correlation of body length with particle size distribution, indicating that the nematodes grew better in coarser sediments. The number of eggs per worm showed relatively high variation among treatments (total mean 12.4 +/- 4.8) and also within treatments (mean +/- 5-95%). C. elegans is a suitable test organism for freshwater sediment bioassays, using body length and percentage of gravid worms as test endpoints.
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Review of Biological Research in Aging,
1990]
The last few years have marked a transition for aging research in Caenorhabditis elegans. Several new lines of work have appeared, most notable of which is the derivation of long-lived strains obtained both from naturally occurring variation and by mutation. The loss of several workers in the field due to retirement or movement to other areas of research as well as the increasingly competitive nature of funding for fundamental, nonclinical research in aging had led to the loss of several labs that in the past have been among the most productive in the field. Other areas of research with C. elegans have continued to advance, and the physical map of the nematode is more than 95% complete. The background material for studying C. elegans has also become much more accessible as a result of the publication of a book detailing much of the nonaging background material for C. elegans [Wood, 1988].
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Med Microbiol Immunol,
2006]
Parasitic nematodes are widespread and important pathogens of humans and other animals. The parasitic nematodes Strongyloides have an unusual life cycle in which there is a facultative free-living generation in addition to the obligate parasitic generation. The genomes of many species of parasitic nematodes, including Strongyloides ratti and Strongyloides stercoralis, have been investigated, principally by expressed sequence tag (EST) analyses. These have discovered very many genes from these parasites but, in so doing, have also revealed how different these species are from each other and from other organisms. Understanding the role and function of these newly discovered genes is now the challenge, made more difficult by the parasitic lifestyle. The genomic information available for parasitic nematodes is allowing new approaches for the control of parasitic nematodes to be considered.
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Parasitol Today,
2000]
Gene discovery programs centred around expressed sequence tag (EST) and genome sequencing projects have predictably led to an exponential surge in the number of parasite gene sequences deposited in public databases. To take advantage of this wealth of sequence information, it is essential to develop rapid methods for elucidating the biological function or mode of action of individual genes. Here, Patricia Kuwabara and Alan Coulson discuss the virtues of a powerful epigenetic gene disruption technique, RNA-mediated interference (RNAi), which was originally developed for the nematode Caenorhabditis elegans. It is anticipated that this technique will not only provide insights into gene function, but also help investigators to mine the genome for candidate drug intervention or vaccine development targets, some of which may not be readily apparent on the basis of sequence information alone.