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[
Parasitol Today,
1996]
Parasitic nematode infections remain a major public health problem in many parts of the world. Because most of the current strategies aimed at controlling parasitic nematode infections have met with only limited success, it may be time to consider alternative approaches. An aspect of nematode biology that has drawn little attention as a target for control is the reproductive process. Although there are numerous facets of the overall reproductive biology of nematodes that hold potential as targets for intervention, Alan Scott here focuses on the male reproductive system, and outlines some of the known unique processes and characteristics of sperm formation and sperm function that could be exploited to block fertilization.
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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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[
iScience,
2023]
The application of omics to study <i>Caenorhabditis elegans</i> (<i>C. elegans</i>) in the context of spaceflight is increasing, illuminating the wide-ranging biological impacts of spaceflight on physiology. In this review, we highlight the application of omics, including transcriptomics, genomics, proteomics, multi-omics, and integrated omics in the study of spaceflown <i>C.&#
xa0;elegans</i>, and discuss the impact, use, and future direction of this branch of research. We highlight the variety of molecular alterations that occur in response to spaceflight, most notably changes in metabolic and neuromuscular gene regulation. These transcriptional features are reproducible and evident across many spaceflown species (e.g., mice and astronauts), supporting the use of <i>C.&#
xa0;elegans</i> as a model organism to study spaceflight physiology with translational capital. Integrating tissue-specific, spatial, and multi-omics approaches, which quantitatively link molecular responses to phenotypic adaptations, will facilitate the identification of candidate regulatory molecules for therapeutic intervention and thus represents the next frontiers in <i>C.&#
xa0;elegans</i> space omics research.
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[
Parasitol Int,
2009]
Filarial nematode parasites, the causative agents of elephantiasis and river blindness, undermine the livelihoods of over one hundred million people in the developing world. Recently, the Filarial Genome Project reported the draft sequence of the ~95 Mb genome of the human filarial parasite Brugia malayi - the first parasitic nematode genome to be sequenced. Comparative genome analysis with the prevailing model nematode Caenorhabditis elegans revealed similarities and differences in genome structure and organization that will prove useful as additional nematode genomes are completed. The Brugia genome provides the first opportunity to comprehensively compare the full gene repertoire of a free-living nematode species and one that has evolved as a human pathogen. The Brugia genome also provides an opportunity to gain insight into genetic basis for mutualism, as Brugia, like a majority of filarial species, harbors an endosybiotic bacterium (Wolbachia). The goal of this review is to provide an overview of the results of genomic analysis and how these observations provide new insights into the biology of filarial species.
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[
Parasite Immunol,
2001]
Filarial nematodes are metazoan parasites with genome sizes of> 100 million base pairs, probably encoding 15 000-20 000 genes. Within this considerable gene complement, it seems likely that filariae have evolved a spectrum of immune evasion products which underpin their ability to live for many years within the human host. Moreover, no suitable vaccine currently exists for human filarial diseases, and few markers have yet been established for diagnostic use. In this review, we bring together biochemical and immunological data on prominent filarial proteins with the exciting new information provided by the Filarial Genome Project's expressed sequence tag (EST) database. In this discussion, we focus on those genes with the highest immunological profile, such as inhibitors of host enzymes, cytokine homologues and stage-specific surface proteins, as well as products associated with the mosquito-borne infective larva which offer the best opportunity for an anti-filarial vaccine. These gene products provide a fascinating glimpse of the molecular repertoire which helminth parasites have evolved to manipulate and evade the mammalian immune response.
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[
Crit Rev Biochem Mol Biol,
2012]
The CCAAT box promoter element and NF-Y, the transcription factor (TF) that binds to it, were among the first cis-elements and trans-acting factors identified; their interplay is required for transcriptional activation of a sizeable number of eukaryotic genes. NF-Y consists of three evolutionarily conserved subunits: a dimer of NF-YB and NF-YC which closely resembles a histone, and the "innovative" NF-YA. In this review, we will provide an update on the functional and biological features that make NF-Y a fundamental link between chromatin and transcription. The last 25 years have witnessed a spectacular increase in our knowledge of how genes are regulated: from the identification of cis-acting sequences in promoters and enhancers, and the biochemical characterization of the corresponding TFs, to the merging of chromatin studies with the investigation of enzymatic machines that regulate epigenetic states. Originally identified and studied in yeast and mammals, NF-Y - also termed CBF and CP1 - is composed of three subunits, NF-YA, NF-YB and NF-YC. The complex recognizes the CCAAT pentanucleotide and specific flanking nucleotides with high specificity (Dorn et al., 1997; Hatamochi et al., 1988; Hooft van Huijsduijnen et al, 1987; Kim & Sheffery, 1990). A compelling set of bioinformatics studies clarified that the NF-Y preferred binding site is one of the most frequent promoter elements (Suzuki et al., 2001, 2004; Elkon et al., 2003; Marino-Ramirez et al., 2004; FitzGerald et al., 2004; Linhart et al., 2005; Zhu et al., 2005; Lee et al., 2007; Abnizova et al., 2007; Grskovic et al., 2007; Halperin et al., 2009; Hakkinen et al., 2011). The same consensus, as determined by mutagenesis and SELEX studies (Bi et al., 1997), was also retrieved in ChIP-on-chip analysis (Testa et al., 2005; Ceribelli et al., 2006; Ceribelli et al., 2008; Reed et al., 2008). Additional structural features of the CCAAT box - position, orientation, presence of multiple Transcriptional Start Sites - were previously reviewed (Dolfini et al., 2009) and will not be considered in detail here.
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[
1983]
In 1974, Sydney Brenner published an elegant paper that described the genetic system of Caenorhabditis elegans and led to its use in research on a wide variety of topics, including aging (Brenner, 1974). Its small size (1mm as an adult) and determinate cell lineage has allowed a description of the entire somatic cell lineage from the one-cell stage to the adult (Sulston and Horvitz, 1977; Deppe et al., 1978; Kimble and Hirsh, 1979; Suslton et al., personal communication). Its ease of culture makes it an organism of choice for studies of various aspects of anatomy and physiology, including muscle formation and function (Zengel and Epstein, 1980; Mackenzie and Epstein, 1980), cuticle formation (Cox et al, 1981), neuroanatomy (Ward et al, 1975; Ware et al, 1975; Sulston et al, 1975), and behavior (Dusenbery, 1980). Several genes have been cloned by recombinant DNA techniques ablation (Kimble, 1981; Laufer and von Ehrenstin, 1981) procedures, as well as most of the modern molecular techniques, are in use.
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[
Cell,
1997]
The demonstrations in two papers in this issue of Cell (Rocheleau et al., 1997; Thorpe et al., 1997) of the involvement of a Wnt pathway in very early embryogenesis in Caenorhabditis elegans provides another significant step toward the ambitious but realistic goal of understanding all the basic strategies used to control embryogenesis in this model organism. At the same time, they challenge some of the prevailing models of Wnt signaling, suggesting that interactions among Wnt pathway components may vary in different developmental processes. With these papers, as well as the earlier reports on Wnt pathway genes
lin-44,
lin-17, and
pop-1 (Herman et al., 1995; Lin et al., 1995; Harris et al., 1996; Sawa et al., 1996) and new studies on Wnt pahtway genes reported in recent meetings, worm breeders have become a significant force in the army of Wnt researchers. They have also illustrated how different systems can provide important new complementary insights.
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[
Front Cell Dev Biol,
2020]
Stem cell development depends on post-transcriptional regulation mediated by RNA-binding proteins (RBPs) (Zhang et al., 1997; Forbes and Lehmann, 1998; Okano et al., 2005; Ratti et al., 2006; Kwon et al., 2013). Pumilio and FBF (PUF) family RBPs are highly conserved post-transcriptional regulators that are critical for stem cell maintenance (Wickens et al., 2002; Quenault et al., 2011). The RNA-binding domains of PUF proteins recognize a family of related sequence motifs in the target mRNAs, yet individual PUF proteins have clearly distinct biological functions (Lu et al., 2009; Wang et al., 2018). The <i>C. elegans</i> germline is a simple and powerful model system for analyzing regulation of stem cell development. Studies in <i>C. elegans</i> uncovered specific physiological roles for PUFs expressed in the germline stem cells ranging from control of proliferation and differentiation to regulation of the sperm/oocyte decision. Importantly, recent studies started to illuminate the mechanisms behind PUF functional divergence. This review summarizes the many roles of PUF-8, FBF-1, and FBF-2 in germline stem and progenitor cells (SPCs) and discusses the factors accounting for their distinct biological functions. PUF proteins are conserved in evolution, and insights into PUF-mediated regulation provided by the <i>C. elegans</i> model system are likely relevant for other organisms.
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[
Cell,
2004]
Heterotrimeric G proteins are well known for their function in signal transduction downstream of seven transmembrane receptors. More recently, however, genetic analysis in C. elegans and in Drosophila has revealed a second, essential function of these molecules in positioning the mitotic spindle and attaching microtubules to the cell cortex. Five new publications in Cell (Afshar et al., 2004; Du and Macara, 2004 [this issue of Cell]; Hess et al., 2004), Developmental Cell (Martin-McCaffrey et al., 2004), and Current Biology (Couwenbergs et al., 2004) show that this function is conserved in vertebrates and-like the classical pathway- involves cycling of G proteins between GDP and GTP bound conformations.