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[
2017]
Caenorhabditis elegans is a 1-mm-long free-living nematode that feeds on bacteria. The feeding organ of C. elegans is a pharynx, a neuromuscular tube responsible for sucking bacteria into the worm from outside, concentrating them, and grinding them up (Doncaster 1962, Seymour et al. 1983). The basic mechanics and the neurons and muscles used to execute feeding motion are important for understanding several feeding behaviors and are therefore briefly described. More details regarding cellular and nuclear composition, the structure, electrophysiology, and the molecular components can be found in Avery and You (2012).
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[
Annu Rev Phytopathol,
2011]
The surface coat (SC) of the plant-parasitic nematode cuticle is an understudied area of current research, even though it likely plays key roles in both nematode-plant and nematode-microbe interactions. Although in several ways Caenorhabditis elegans is a poor model for plant-parasitic nematodes, it is a useful starting point for investigations of the cuticle and its SC, especially in the light of recent work using this species as a model for innate immunity and the generic biology underpinning much host-parasite biology. We review the research focused on the involvement of the SC of plant-parasitic nematodes. Using the insights gained from animal-parasitic nematodes and other sequenced nematodes, we discuss the key roles that the SC may play.
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[
Sex Dev,
2023]
The nematode, Caenorhabiditis elegans has proven itself as a valuable model for investigating metazoan biology. Key features including a transparent body, an invariant cell lineage, ease of genetic manipulation, coupled with a high level of genetic conservation with higher eukaryotes make C. elegans a desierable model organism. Although used to elucidate many aspects of somatic biology, a distinct advantage of C. elegans is its well annotated germline which allows all aspects of oogenesis to be observed in real-time within a single animal. C. elegans hermaphrodites have two large germlines which produce their own sperm that is later stored to fertilize their own oocytes. These two germlines take up much of the internal space of each animal and therefore, germ cells are the most abundant cell present within each animal. This feature has allowed many novel findings that established early understanding of germ cell dynamics, as well as key features of meiosis and germ cell maturation to be unveiled. This review will focus on the key features that make C. elegans an outstanding model for exploring each feature of oogenesis. This will include the fundamental steps associated with germ line function and germ cell maturation and will be of use for those interested in exploring reproductive metazoan biology.
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[
Methods Mol Biol,
2006]
Single-nucleotide polymorphism (SNP) mapping is the easiest and most reliable way to map genes in Caenorhabditis elegans. SNPs are extremely dense and usually have no associated phenotype, making them ideal markers for mapping. SNP mapping has three steps. First, recombinant mutant animals are generated over a polymorphic strain (usually CB4856) using standard genetic techniques. Second, the genotype of these animals at SNP loci is determined using one of a variety of SNP detection technologies. Third, linkage between the mutant and one or more SNPs is used to position the mutant on the chromosome relative to the SNPs. This chapter presents a detailed procedure for generating recombinant animals, for assaying SNPs using restriction enzymes, and for analyzing mapping data.
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[
Cell,
2007]
Several extracellular factors, including Wnt proteins, have been reported to induce synapse formation. In this issue, Klassen and Shen (2007) report that Wnt proteins can also act as antisynaptogenic signals to prevent synapse formation in certain parts of the worm Caenorhabditis elegans. The differential response of axon populations to local Wnt proteins may contribute to the patterning of synaptic connections.
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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.