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Ogura, K. -ichi, Asakura, T., & Goshima, Y. (2012). Localization mechanisms of the axon guidance molecule UNC-6/Netrin and its receptors, UNC-5 and UNC-40, in Caenorhabditis elegans. Dev Growth Differ, 54(3), 390–397.
Abstract: Netrin is an evolutionarily conserved, secretory axon guidance molecule. Netrin's receptors, UNC-5 and UNC-40/DCC, are single trans-membrane proteins with immunoglobulin domains at their extra-cellular regions. Netrin is thought to provide its positional information by establishing a concentration gradient. UNC-5 and UNC-40 act at growth cones, which are specialized axonal tip structures that are generally located at a long distance from the neural cell body. Thus, the proper localization of both Netrin and its receptors is critical for their function. This review addresses the localization mechanisms of UNC-6/Netrin and its receptors in Caenorhabditis elegans, focusing on our recent reports. These findings include novel insights on cytoplasmic proteins that function upstream of the receptors.
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Riddle, D. L., Blumenthal, T., Meyer, B. J., & Priess, J. R. (1997). C. elegans II, 2nd edition. Cold Spring Harbor (NY): Cold Spring Harbor Laboratory Press.
Abstract: Why should one study a worm? This simple creature is one of several “model” organisms that together have provided tremendous insight into how all organisms are put together. It has become increasingly clear over the past two decades that knowledge from one organism, even one so simple as a worm, can provide tremendous power when connected with knowledge from other organisms. And because of the experimental accessibility of nematodes, knowledge about worms can come more quickly and cheaply than knowledge about higher organisms.
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Sakube, Y., Ando, H., & Kagawa, H. (1997). An abnormal ketamine response in mutants defective in the ryanodine receptor gene ryr-1 (unc-68) of Caenorhabditis elegans. J Mol Biol, 267(4), 849–864.
Abstract: To characterize excitation-contraction coupling in Caenorhabditis elegans, we applied two approaches. First, we isolated a mutant having abnormal responses to ketamine, an anesthetic in vertebrates. The novel mutation unc-68(kh30) (isolated as kra-1(kh30)), exhibited strict ketamine-dependent convulsions followed by paralysis. Second, we cloned the C. elegans ryanodine receptor gene ryr-1 that is located near the center of chromosome V. ryr-1 consists of 46 exons, which encode a predicted protein of 5071 amino acid residues that is homologous to Drosophila and vertebrate ryanodine receptors. ryr-1 promoter/lacZ plasmids were expressed in body-wall and pharyngeal muscles. Non-muscle cell expression may be seen with a truncated promoter. In addition, we show that the unc-68/kra-1(kh30) mutation is a Ser1444 Asn substitution at a putative protein kinase C phosphorylation site in ryr-1, and that unc-68(e540) contains a splice acceptor mutation that creates a premature stop codon in the ryr-1 gene. We confirmed that unc-68(e540) is a mutation in ryr-1 by injecting the complete ryr-1 gene into unc-68(e540) animals and recovering wild-type progeny. Results presented here will be useful in studying the structure and function of ryanodine receptors in excitation-contraction coupling and in understanding the evolution of ryanodine receptor tissue specificity.
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Sterken, M. G., Snoek, L. B., Kammenga, J. E., & Andersen, E. C. (2015). The laboratory domestication of Caenorhabditis elegans. Trends Genet, 31(5), 224–231.
Abstract: Model organisms are of great importance to our understanding of basic biology and to making advances in biomedical research. However, the influence of laboratory cultivation on these organisms is underappreciated, and especially how that environment can affect research outcomes. Recent experiments led to insights into how the widely used laboratory reference strain of the nematode Caenorhabditis elegans compares with natural strains. Here we describe potential selective pressures that led to the fixation of laboratory-derived alleles for the genes npr-1, glb-5, and nath-10. These alleles influence a large number of traits, resulting in behaviors that affect experimental interpretations. Furthermore, strong phenotypic effects caused by these laboratory-derived alleles hinder the discovery of natural alleles. We highlight strategies to reduce the influence of laboratory-derived alleles and to harness the full power of C. elegans.
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Thacker, C., & Rose, A. M. (2000). A look at the Caenorhabditis elegans Kex2/Subtilisin-like proprotein convertase family. Bioessays, 22(6), 545–553.
Abstract: Significant advances have recently been made in our understanding of the mechanisms of activation of proteins that require processing. Often this involves endoproteolytic cleavage of precursor forms at basic residues, and is carried out by a group of serine endoproteinases, termed the proprotein convertases. In mammals, seven different convertases have been identified to date. These act in both the regulated secretory pathway for the processing of prohormones and proneuropeptides and in the constitutive secretory pathway, in which a variety of proproteins are activated endoproteolytically. The recently completed sequence of the nematode Caenorhabditis elegans genome affords a unique opportunity to examine the entire proprotein convertase family in a multicellular organism. Here we review the nature of the family, emphasising the structural features, characteristic of the four nematode genes, that supply all of the necessary functions unique to this group of serine endoproteinases. Studies of the C. elegans genes not only provide important information about the evaluation of this gene family but should help to illuminate the roles of these proteins in mammalian systems. BioEssays 22:545-553, 2000.
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