Analysis of osm-6, a Gene That Affects Sensory Cilium Structure and Sensory Neuron Function in Caenorhabditis elegans

Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 187-200 ◽  
Author(s):  
Joan Collet ◽  
Caroline A Spike ◽  
Erik A Lundquist ◽  
Jocelyn E Shaw ◽  
Robert K Herman

AbstractMutation in the Caenorhabditis elegans gene osm-6 was previously shown to result in defects in the ultrastructure of sensory cilia and defects in chemosensory and mechanosensory behaviors. We have cloned osm-6 by transposon tagging and transformation rescue and have identified molecular lesions associated with five osm-6 mutations. The osm-6 gene encodes a protein that is 40% identical in amino acid sequence to a predicted mammalian protein of unknown function. We fused osm-6 with the gene for green fluorescent protein (GFP); the fusion gene rescued the osm-6 mutant phenotype and showed accumulation of GFP in ciliated sensory neurons exclusively. The OSM-6::GFP protein was localized to cytoplasm, including processes and dendritic endings where sensory cilia are situated. Mutations in other genes known to cause ciliary defects led to changes in the appearance of OSM-6::GFP in dendritic endings or, in the case of daf-19, reduced OSM-6::GFP accumulation. We conclude from an analysis of genetic mosaics that osm-6 acts cell autonomously in affecting cilium structure.

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1335-1351
Author(s):  
Juan E Abrahante ◽  
Eric A Miller ◽  
Ann E Rougvie

Abstract The heterochronic genes lin-4, lin-14, lin-28, and lin-29 specify the timing of lateral hypodermal seam cell terminal differentiation in Caenorhabditis elegans. We devised a screen to identify additional genes involved in this developmental timing mechanism based on identification of mutants that exhibit temporal misexpression from the col-19 promoter, a downstream target of the heterochronic gene pathway. We fused the col-19 promoter to the green fluorescent protein gene (gfp) and demonstrated that hypodermal expression of the fusion gene is adult-specific in wild-type animals and temporally regulated by the heterochronic gene pathway. We generated a transgenic strain in which the col-19::gfp fusion construct is not expressed because of mutation of lin-4, which prevents seam cell terminal differentiation. We have identified and characterized 26 mutations that restore col-19::gfp expression in the lin-4 mutant background. Most of the mutations also restore other aspects of the seam cell terminal differentiation program that are defective in lin-4 mutant animals. Twelve mutations are alleles of three previously identified genes known to be required for proper timing of hypodermal terminal differentiation. Among these are four new alleles of lin-42, a heterochronic gene for which a single allele had been described previously. Two mutations define a new gene, lin-58. When separated from lin-4, the lin-58 mutations cause precocious seam cell terminal differentiation and thus define a new member of the heterochronic gene pathway.


Genetics ◽  
1999 ◽  
Vol 153 (4) ◽  
pp. 1673-1682
Author(s):  
Shanta Rajaram ◽  
Ted L Spangler ◽  
Margaret M Sedensky ◽  
Phil G Morgan

Abstract The mechanism of action of volatile anesthetics is unknown. In Caenorhabditis elegans, mutations in the gene unc-1 alter anesthetic sensitivity. The protein UNC-1 is a close homologue of the mammalian protein stomatin. Mammalian stomatin is thought to interact with an as-yet-unknown ion channel to control sodium flux. Using both reporter constructs and translational fusion constructs for UNC-1 and green fluorescent protein (GFP), we have shown that UNC-1 is expressed primarily within the nervous system. The expression pattern of UNC-1 is similar to that of UNC-8, a sodium channel homologue. We examined the interaction of multiple alleles of unc-1 and unc-8 with each other and with other genes affecting anesthetic sensitivity. The data indicate that the protein products of these genes interact, and that an UNC-1/UNC-8 complex is a possible anesthetic target. We propose that membrane-associated protein complexes may represent a general target for volatile anesthetics.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 3062-3062 ◽  
Author(s):  
Khurum Hayat Khan ◽  
Anna-Mary Young ◽  
Joaquin Mateo ◽  
Nina Tunariu ◽  
Timothy Anthony Yap ◽  
...  

3062 Background: GL-ONC is a genetically engineered virus attenuated by insertion of the ruc-gfp (Renilla luciferase and Aequorea green fluorescent protein fusion gene), beta-galactosidase (lacZ) and beta-glucuronidase (gusA) reporter genes into the FL14.5L, J2R (thymidine kinase) and A56R (hemagglutinin) loci, respectively. A phase I trial of intravenous (i.v) GL-ONC1 was pursued to evaluate safety, tolerability, tumour delivery, neutralising antibody development and antitumor activity. Methods: GL-ONC1 was administered at escalating doses (1x105, 1x106, 1x107, 1x108, 1x109, 3x109 plaque forming units (pfu) on day 1; 1.667x107 and 1.667x108, 1.667x109pfu on days 1-3) utilizing a 28-day cycle and a 3+3 dose escalation design. Paired biopsies before treatment and on day 8 for pharmacodynamic and viral delivery evaluation were obtained. Green flourescent protein (GFP) imaging was performed on skin rash and mucosal tumour lesions at baseline and after each cycle. Results: To date, 33 patients (pts) across 8 cohorts have been treated with 1 dose limiting toxicty reported of grade 3 transaminitis after a single infusion at 1x109pfu. Other reported adverse events (n) included pyrexia (26), musculoskeletal pain (10), fatigue (8), nausea and vomiting (4). 2 pts had transient transaminitis; both had liver metastases, which may have contributed to this. 2 pts developed minimally symptomatic poxvirus skin pustules, which appeared green by GFP and were positive to viral plaque assay (VPA). Overall, stable disease (SD) by RECIST was seen at >24 weeks (n=6) and 8-12 weeks (n=5). 2 out of 4 pts in cohort 8 (one with cholangiocarcinoma and another with non-small cell lung caner) achieved SD for median 5.5 months, with a drop in tumour markers at the time of infusions. Conclusions: GL-ONC1 is well tolerated; more frequent delivery of the virus (2 weekly, at the same dose) is planned in an attempt to increase agent exposure. Clinical trial information: NCT009794131.


Development ◽  
1999 ◽  
Vol 126 (21) ◽  
pp. 4839-4848 ◽  
Author(s):  
M. Fujiwara ◽  
T. Ishihara ◽  
I. Katsura

To elucidate the mechanism of sensory cilium formation, we analyzed mutants in the Caenorhabditis elegans che-2 gene. These mutants have extremely short cilia with an abnormal posterior projection, and show defects in behaviors that are mediated by ciliated sensory neurons. The che-2 gene encodes a new member of the WD40 protein family, suggesting that it acts in protein-protein interaction. Analysis of mutation sites showed that both the amino-terminal WD40 repeats and the carboxyl-terminal non-WD40 domain are necessary for the CHE-2 function. CHE-2-tagged green fluorescent protein is localized at the cilia of almost all the ciliated sensory neurons. Expression of che-2 in a subset of sensory neurons of a che-2 mutant by using a heterologous promoter resulted in restoration of the functions and cilium morphology of only the che-2-expressing neurons. Thus, che-2 acts cell-autonomously. This technique can be used in the future for determining the function of each type of che-2-expressing sensory neuron. Using green fluorescent protein, we found that the extension of cilia in wild-type animals took place at the late embryonic stage, whereas the cilia of che-2 mutant animals remained always short during development. Hence, the abnormal posterior projection is due to the inability of cilia to extend, rather than degeneration of cilia once correctly formed. Expression of che-2 in a che-2 mutant under a heat shock promoter showed that the extension of cilia, surprisingly, can occur even at the adult stage, and that such cilia can function apparently normally in behavior.


2002 ◽  
Vol 361 (2) ◽  
pp. 221-230 ◽  
Author(s):  
Yusuke KATO ◽  
Tomoyasu AIZAWA ◽  
Hirokazu HOSHINO ◽  
Keiichi KAWANO ◽  
Katsutoshi NITTA ◽  
...  

Two genes encoding the ASABF (Ascarissuumantibacterial factor)-type antimicrobial peptide, abf-1 and abf-2, were identified in Caenorhabditis elegans. Recombinant ABF-2 exhibited potent microbicidal activity against Gram-positive and Gram-negative bacteria, and yeasts. The tissue-specific distribution estimated by immunofluorescence staining and transgenic analysis of a gfp fusion gene (where GFP corresponds to green fluorescent protein) suggested that ABF-2 contributes to surface defence in the pharynx. abf-1 contains a single intron at a conserved position, suggesting that asabf and abf originated from a common ancestor. Both transcripts for abf-1 and abf-2 were detected as two distinct forms, i.e. spliced leader (SL)1-trans-spliced with a long 5′-untranslated region (UTR) and SL-less with a short 5′-UTR. A polycistronic precursor RNA encoding ABF-1 and ABF-2 was detected, suggesting that these genes form an operon. An ‘opportunistic operon’ model for regulation of abf genes, including the generation of short SL-less transcripts, is proposed. In conclusion, C. elegans should have an immune defence system due to the antimicrobial peptides. C. elegans can be a novel model for innate immunity. Furthermore, the combination of biochemical identification in Ascaris suum and homologue hunting in C. elegans should be a powerful method of finding rapidly evolved proteins, such as some immune-related molecules in C. elegans.


Endocrinology ◽  
2005 ◽  
Vol 146 (1) ◽  
pp. 406-413 ◽  
Author(s):  
Yoichi Ueta ◽  
Hiroaki Fujihara ◽  
Ryota Serino ◽  
Govindan Dayanithi ◽  
Hitoshi Ozawa ◽  
...  

We have generated transgenic rats expressing an arginine vasopressin (AVP)-enhanced green fluorescent protein (eGFP) fusion gene. The expression of the eGFP gene and strong fluorescence were observed in the supraoptic nucleus (SON), the paraventricular nucleus (PVN), and the suprachiasmatic nucleus (SCN) in transgenic rats. The hypothalamo-neurohypophyseal tract, isolated SON neurons, and isolated axon terminals in the neurohypophysis also showed robust eGFP fluorescence. Water deprivation for 2 d increased the fluorescence of the eGFP in the SON and the PVN but not the SCN. The whole-cell patch-clamp technique was then used to record the electrical activities specifically identifying eGFP-expressing SON, PVN, and SCN AVP neurons in in vitro brain slice preparations. The AVP-eGFP transgenic rats are a unique new tool with which to study the physiological role of AVP-secreting neurons in the central nervous system and the dynamics of the regulation of AVP secretion in the living neurons and their axon terminals.


1996 ◽  
Vol 134 (2) ◽  
pp. 537-548 ◽  
Author(s):  
T A Starich ◽  
R Y Lee ◽  
C Panzarella ◽  
L Avery ◽  
J E Shaw

The Drosophila melanogaster genes Passover and l(1)ogre and the Caenorhabditis elegans gene unc-7 define a gene family whose function is not known. We have isolated and characterized the C. elegans gene eat-5, which is required for synchronized pharyngeal muscle contractions, and find that it is a new member of this family. Simultaneous electrical and video recordings reveal that in eat-5 mutants, action potentials of muscles in the anterior and posterior pharynx are unsynchronized. Injection of carboxyfluorescein into muscles of the posterior pharynx demonstrates that all pharyngeal muscles are dye-coupled in wild-type animals; in eat-5 mutants, however, muscles of the anterior pharynx are no longer dye-coupled to posterior pharyngeal muscles. We show that a gene fusion of eat-5 to the green fluorescent protein is expressed in pharyngeal muscles. unc-7 and eat-5 are two of at least sixteen members of this family in C. elegans as determined by database searches and PCR-based screens. The amino acid sequences of five of these members in C. elegans have been deduced from cDNA sequences. Polypeptides of the family are predicted to have four transmembrane domains with cytoplasmic amino and carboxyl termini. We have constructed fusions of one of these polypeptides with beta-galactosidase and with green fluorescent protein. The fusion proteins appear to be localized in a punctate pattern at or near plasma membranes. We speculate that this gene family is required for the formation of gap junctions.


2004 ◽  
Vol 32 (5) ◽  
pp. 682-684 ◽  
Author(s):  
J.M. Scholey ◽  
G. Ou ◽  
J. Snow ◽  
A. Gunnarson

IFT (intraflagellar transport) assembles and maintains sensory cilia on the dendritic endings of chemosensory neurons within the nematode Caenorhabditis elegans. During IFT, macromolecular protein complexes called IFT particles (which carry ciliary precursors) are moved from the base of the sensory cilium to its distal tip by anterograde IFT motors (kinesin-II and Osm-3 kinesin) and back to the base by retrograde IFT-dynein [Rosenbaum and Witman (2002) Nat. Rev. Mol. Cell Biol. 3, 813–825; Scholey (2003) Annu. Rev. Cell Dev. Biol. 19, 423–443; and Snell, Pan and Wang (2004) Cell 117, 693–697]. In the present study, we describe the protein machinery of IFT in C. elegans, which we have analysed using time-lapse fluorescence microscopy of green fluorescent protein-fusion proteins in concert with ciliary mutants.


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