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Parasite Immunol
]
Filarial nematode parasites, the causative agents for a spectrum of acute and chronic diseases including lymphatic filariasis and river blindness, threaten the well-being and livelihood of hundreds of millions of people in the developing regions of the world. The 2007 publication on a draft assembly of the 95-Mb genome of the human filarial parasite Brugia malayi- representing the first helminth parasite genome to be sequenced - has been followed in rapid succession by projects that have resulted in the genome sequencing of six additional filarial species, seven nonfilarial nematode parasites of animals and nearly 30 plant parasitic and free-living species. Parallel to the genomic sequencing, transcriptomic and proteomic projects have facilitated genome annotation, expanded our understanding of stage-associated gene expression and provided a first look at the role of epigenetic regulation of filarial genomes through microRNAs. The expansion in filarial genomics will also provide a significant enrichment in our knowledge of the diversity and variability in the genomes of the endosymbiotic bacterium Wolbachia leading to a better understanding of the genetic principles that govern filarial-Wolbachia mutualism. The goal here is to provide an overview of the trends and advances in filarial and Wolbachia genomics.
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Curr Biol,
2002]
Genes for tiny RNAs have been found to be plentiful in the genomes of worms, flies, humans and probably all animals. Some of these microRNAs have been conserved through evolution, and many are expressed only at specific times or places. How they act is just beginning to be understood, but their importance to biology is likely to be great.
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Science,
2002]
Genomes are databases sensitive to invasion by viruses. In recent years, a defense mechanism has been discovered, which turns out to be conserved among eukaryotes. The system can be compared to the immune system in several ways: It has specificity against foreign elements and the ability to amplify and raise a massive response against an invading nucleic acid. The latter property is beginning to be understood at the molecular level.
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ACS Chem Biol,
2006]
Identification of bioactive molecules and their targets impedes the process of drug development. In a recent paper, a genetically tractable organism, the Caenorhabditis elegans worm, is shown to be a viable screening system in which the drug target and the pathway it activates can be readily identified.
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Trends Parasitol,
2009]
Neuropeptides are small messenger molecules that can be found in all metazoans, where they govern a diverse array of physiological processes. Because neuropeptides seem to be conserved among pest species, selected peptides can be considered as attractive targets for drug discovery. Much can be learned from the model system Caenorhabditis elegans because of the availability of a sequenced genome and state-of-the-art postgenomic technologies that enable characterization of endogenous peptides derived from neuropeptide-like protein (NLP) precursors. Here, we provide an overview of the NLP peptide family in C. elegans and discuss their resemblance with arthropod neuropeptides and their relevance for anthelmintic discovery.
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Nature,
1990]
Fruitflies and nematodes show many similarities in the general organization of the gene networks that control sexual dimorphism and dosage compensation. In contrast, the underlying molecular mechanisms appear to be very different in these two species. Developmental processes such as sex determination need not be strongly conserved in evolution.
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Curr Opin Genet Dev,
2012]
The identity of individual cell types in a multicellular organism appears to be continuously maintained through active processes but is not irreversible. Changes in the identity of individual cell types can be brought about through ectopic mis-expression of regulatory factors, but in a number of cases also occurs in normal development. I will review here these natural cellular reprogramming processes occurring in the invertebrate model organisms Caenorhabditis elegans and Drosophila melanogaster. Furthermore, I will discuss the issue of why only certain cell types can be converted during induced reprogramming processes evoked by ectopic expression of regulatory factors and how recent work in model systems have shown that this cellular context-dependency can be manipulated.
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Crit Rev Biochem Mol Biol,
1999]
Although largely hidden from public view, nematodes are among the most numerous and ecologically diverse multicellular organisms inhabiting the planet. Although most species are microbivorous, numerous species are economically or medically important parasites of plants and animals. As Cobb wrote 80 years ago, "If all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes and oceans represented by a film of nematodes. The locations of towns would be decipherable, since for every massing of human beings there would be a corresponding massing of certain nematodes. The location of the various plants and animals would still be decipherable, and has we sufficient knowledge, in many cases their species could be determined by an examination of their erstwhile nematode parasites".
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Int J Parasitol,
2006]
Information on the functional genomics of Caenorhabditis elegans has increased significantly in the last few years with the development of RNA interference. In parasitic nematodes, RNA interference has shown some success in gene knockdown but optimisation of this technique will be required before it can be adopted as a reliable functional genomics tool. Comparative studies in C. elegans remain an appropriate alternative for studying the function and regulation of some parasite genes and will be extremely useful for fully exploiting the increasing parasite genome sequence data becoming available.
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Dev Dyn,
2009]
Gastrulation is a time during development when cells destined to produce internal tissues and organs move from the surface of the embryo into the interior. It is critical that the cell movements of gastrulation be precisely controlled, and coordinated with cell specification, in order for the embryo to develop normally. Caenorhabditis elegans gastrulation is relatively simple, can be observed easily in the transparent embryo, and can be manipulated genetically to uncover important regulatory mechanisms. Many of these cellular and molecular mechanisms, including cell shape, cytoskeletal, and cell cycle changes, appear to be conserved from flies to vertebrates. Here we review gastrulation in C. elegans, with an emphasis on recent data linking contact-induced cell polarity, PAR proteins, and cell fate specification to gastrulation control.