141.
trans-splicing of nematode pre-messenger RNA - Hannon, Gregory James
We have used the parasitic nematode, Ascaris, as a model system for the biochemical analysis of nematode gene expression. Cell free extracts derived from synchronously developing Ascaris embryos have proven remarkably versatile for reproducing a variety of cellular processes in vitro. These extracts catalyze accurate transcription of RNA polymerase II and RNA polymerase III genes as well as cis- and trans-splicing. Nematodes are among the few organisms which are known to carry out intermolecular (trans) RNA splicing. Ascaris extracts are unique in their ability to catalyze trans-splicing in vitro. In these extracts, the spliced leader sequence is donated to a...
142.
MSP Dynamics Drives Nematode Sperm Locomotion
ABSTRACT Most eukaryotic cells can crawl over surfaces. In general, this motility requires three sequential actions: polymerization at the leading edge, adhesion to the substrate, and retraction at the rear. Recent in vitro experiments with extracts from spermatozoa from the nematode Ascaris suum suggest that retraction forces are generated by depolymerization of the major sperm protein cytoskeleton. Combining polymer entropy with a simple kinetic model for disassembly we propose a model for disassembly-induced retraction that fits the in vitro experimental data. This model explains the mechanism by which disassembly of the cytoskeleton generates the force necessary to pull the cell...
143.
Intestinal Nematode Infection Ameliorates Experimental Colitis in Mice - Khan, W. I.; Blennerhasset, P. A.; Varghese, A. K.; Chowdhury, S. K.; Omsted, P.; Deng, Y.; Collins, S. M.
Epidemiological studies suggest that inflammatory bowel disease (IBD) is common in developed countries and rare in countries where intestinal nematode infections are common. T cells are critical in many immune responses, including those associated with IBD and nematode infection. Among the distinct T helper (Th) cell subsets, Th1-type immune response is predominantly associated with Crohn's disease, while many nematode infections generate a strong Th2 response. The reciprocal cross regulation between Th1 and Th2 cells suggests that generation of a Th2 response by nematodes could prevent or reduce the effects of Th1-mediated diseases. In the present study, we investigated the effect...
144.
Phylogenetic Relationships of the Wolbachia of Nematodes and Arthropods - Fenn, Katelyn; Conlon, Claire; Jones, Martin; Quail, Michael A; Holroyd, Nancy E; Parkhill, Julian; Blaxter, Mark
Wolbachia are well known as bacterial symbionts of arthropods, where they are reproductive parasites, but have also been described from nematode hosts, where the symbiotic interaction has features of mutualism. The majority of arthropod Wolbachia belong to clades A and B, while nematode Wolbachia mostly belong to clades C and D, but these relationships have been based on analysis of a small number of genes. To investigate the evolution and relationships of Wolbachia symbionts we have sequenced over 70 kb of the genome of wOvo, a Wolbachia from the human-parasitic nematode Onchocerca volvulus, and compared the genes identified to orthologues...
145.
Intestinal Nematode Infection Ameliorates Experimental Colitis in Mice - Khan, W. I.; Blennerhasset, P. A.; Varghese, A. K.; Chowdhury, S. K.; Omsted, P.; Deng, Y.; Collins, S. M.
Epidemiological studies suggest that inflammatory bowel disease (IBD) is common in developed countries and rare in countries where intestinal nematode infections are common. T cells are critical in many immune responses, including those associated with IBD and nematode infection. Among the distinct T helper (Th) cell subsets, Th1-type immune response is predominantly associated with Crohn's disease, while many nematode infections generate a strong Th2 response. The reciprocal cross regulation between Th1 and Th2 cells suggests that generation of a Th2 response by nematodes could prevent or reduce the effects of Th1-mediated diseases. In the present study, we investigated the effect...
146.
Phylogenetic Relationships of the Wolbachia of Nematodes and Arthropods - Fenn, Katelyn; Conlon, Claire; Jones, Martin; Quail, Michael A; Holroyd, Nancy E; Parkhill, Julian; Blaxter, Mark
Wolbachia are well known as bacterial symbionts of arthropods, where they are reproductive parasites, but have also been described from nematode hosts, where the symbiotic interaction has features of mutualism. The majority of arthropod Wolbachia belong to clades A and B, while nematode Wolbachia mostly belong to clades C and D, but these relationships have been based on analysis of a small number of genes. To investigate the evolution and relationships of Wolbachia symbionts we have sequenced over 70 kb of the genome of wOvo, a Wolbachia from the human-parasitic nematode Onchocerca volvulus, and compared the genes identified to orthologues...
147.
Diversity and abundance of nematodes in agroecosystems of Kenya - Kimenju, JW; Faculty of Agriculture, University of Nairobi, P.O. Box 30197 Nairobi, Kenya.;; Karanja, NK; Faculty of Agriculture, University of Nairobi, P.O. Box 30197 Nairobi, Kenya.;; Nyongesa, MW; Faculty of Agriculture, University of Nairobi, P.O. Box 30197 Nairobi, Kenya.;
A review of nematodes associated with crops has revealed that almost every crop or group of crops is attacked by one or several nematode pests, which cause economic losses in heavily infested fields. The most commonly reported nematodes belong to the genera Meloidogyne Goeldi, Pratylenchus, Filip'jev, Helicotylenchus, Steiner Scutellonema, Andrassy, Tylenchorhynchus, Cobb Xiphinema, Trichodorus, Cobb, Radopholus Thorne, Aphelenchoides, and Ditylenchus. Overall, populations of plant parasitic nematodes and their diversity decreases with intensity of land cultivation especially if the same crop or where a narrow range of crops is cultivated. The distribution of plant parasitic nematodes is influenced by many factors...
148.
Parasitism of the root-lesion nematode Pratylenchus thornei on chickpea - Castillo, Pablo; Jiménez-Díaz, Rafael M.; Gómez Barcina, Antonio; Vovlas, Nicola
Pratylenchus thornei-chickpea interactions were investigated under controlled and fluctuating environmental conditions in the growth chamber, greenhouse and shadehouse. Under controlled conditions. P. thornei infected chickpea hnes 12071/10054 and P2245 and cultivars Andoum 1, JG62 and UC 27. Line P 2245 and cv. JG 62 were the most susceptible genotypes on the basis of root damage and nematode reproduction, but nematode infection did not significantly reduce root and shoot weights. Cultivars Andoum 1 and UC27 and line 12071/10054 showed the least root damage and nematode reproduction. Inoculation of cv. Andoum 1 with 2500, 5000 or lOOOO nematodes per plant in pots...
149.
The nucleotide sequence of a nematode vitellogenin gene. - Spieth, J; Denison, K; Zucker, E; Blumenthal, T
The nematode, Caenorhabditis elegans, contains a family of six genes that code for vitellogenins. Here we report the complete nucleotide sequence of one of these genes, vit-5. The gene specifies a mRNA of 4869 nucleotides, including untranslated regions of 9 bases at the 5' end and 51 bases at the 3' end. Vit-5 contains four short introns totalling 218 bp. The predicted vitellogenin, yp170A, has a molecular weight of 186,430. At its N terminus it is clearly related to the vitellogenins of vertebrates. However, the vit-5-encoded protein does not contain a serine-rich sequence related to the vertebrate vitellin, phosvitin. In...
150.
The nucleotide sequence of a nematode vitellogenin gene. - Spieth, J; Denison, K; Zucker, E; Blumenthal, T
The nematode, Caenorhabditis elegans, contains a family of six genes that code for vitellogenins. Here we report the complete nucleotide sequence of one of these genes, vit-5. The gene specifies a mRNA of 4869 nucleotides, including untranslated regions of 9 bases at the 5' end and 51 bases at the 3' end. Vit-5 contains four short introns totalling 218 bp. The predicted vitellogenin, yp170A, has a molecular weight of 186,430. At its N terminus it is clearly related to the vitellogenins of vertebrates. However, the vit-5-encoded protein does not contain a serine-rich sequence related to the vertebrate vitellin, phosvitin. In...
151.
OX40 interactions in gastrointestinal nematode infection - Ierna, Michelle X; Scales, Hannah E; Schwarz, Herbert; Bunce, Campbell; McIlgorm, Anne; Garside, Paul; Lawrence, Catherine E
The immune expulsion of gastrointestinal nematode parasites is usually associated with T helper type 2 (Th2) responses, but the effector mechanisms directly responsible for parasite loss have not been elucidated. The intestinal inflammatory response accompanying infection with gastrointestinal helminths is thought to be a contributory factor leading to the expulsion of the parasite. However, we have shown that the intestinal inflammation, which is controlled by interleukin (IL)-4, is not required for parasite expulsion. OX40OX40 ligand (L) signals have been shown to be important for the development of Th2 immune responses but are also involved in a number of inflammatory diseases...
152.
Acanthocytes of Stropharia rugosoannulata Function as a Nematode-Attacking Device - Luo, Hong; Li, Xuan; Li, Guohong; Pan, Yanbo; Zhang, Keqin
Efficient killing of nematodes by Stropharia rugosoannulata Farlow ex Murrill cultures was observed. This fungus showed the ability to immobilize the free-living nematode Panagrellus redivivus Goodey within minutes and to immobilize the pine wilt nematode Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle within hours on agar plates. Moreover, P. redivivus worms were completely degraded by the fungus within 24 to 48 h. The cultures of S. rugosoannulata studied shared the characteristic of abundantly producing cells with finger-like projections called acanthocytes. We showed that the nematode-attacking activity of this fungus is carried out by these spiny acanthocytes and that mechanical force is...
153.
Acanthocytes of Stropharia rugosoannulata Function as a Nematode-Attacking Device - Luo, Hong; Li, Xuan; Li, Guohong; Pan, Yanbo; Zhang, Keqin
Efficient killing of nematodes by Stropharia rugosoannulata Farlow ex Murrill cultures was observed. This fungus showed the ability to immobilize the free-living nematode Panagrellus redivivus Goodey within minutes and to immobilize the pine wilt nematode Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle within hours on agar plates. Moreover, P. redivivus worms were completely degraded by the fungus within 24 to 48 h. The cultures of S. rugosoannulata studied shared the characteristic of abundantly producing cells with finger-like projections called acanthocytes. We showed that the nematode-attacking activity of this fungus is carried out by these spiny acanthocytes and that mechanical force is...
154.
Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes - Pi?kiewicz, Anna M.; Duyts, Henk; Berg, Matty P.; Costa, Sofia R.; Putten, Wim H.
Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis is capable of reducing the performance of the dominant grass Ammophila arenaria (Marram grass). However, field surveys show that populations of this nematode usually are controlled to nondamaging densities, but the control mechanism is unknown. In the present study, we first established that T. ventralis populations are top-down controlled by soil biota. Then, selective removal of soil fauna suggested that soil microorganisms...
155.
Control biológico del picudo negro (Scyphophorus interstitialis Gyllenhal) con nemátodos y hongos entomopatógenos en agave en Oaxaca, México - Aquino Bolaños, Teodulfo; Ruiz Vega, Jaime; Iparraguirre Cruz, Miguel
Esta investigación se realizó en condiciones de laboratorio y campo. Los experimentos de laboratorio se realizaron en el CIIDIR-IPN-Oaxaca en el año 2005, mientras que los experimentos de campo se desarrollaron en la localidad de Tlacolula, Oaxaca durante el 2006. Además, se evaluó el efecto de la bacteria Erwinia carotovora contra hongos y nemátodos entomopatógenos. En la fase de laboratorio se evaluaron dos especies de hongos y cuatro especies de nemátodos entomopatógenos y en campo se evaluó un hongo y cuatro especies de nemátodos sobre el picudo negro Scyphophorus interstitialis Gyllenhal. De los de laboratorio, se puede afirmar que E....
156.
?-Glucuronidase Mutants of the Nematode CAENORHABDITIS ELEGANS - Sebastiano, Marisa; D'Alessio, Marina; Bazzicalupo, Paolo
Using a screening procedure that is based on a histochemical stain for the enzyme ?-glucuronidase, we have isolated several mutants of the nematode Caenorhabditis elegans affected in ?-glucuronidase activity. All of the mutations fall into one complementation group and identify a new gene, gus-1, which has been mapped on the right arm of linkage group I (LG I), 1.1 map units to the left of unc-54. The mutants have no visible phenotype, and their viabilities and fertilities are unaffected. Linked revertants of two of the mutations have been isolated. They restore enzyme activity to almost wild-type levels; the ?-glucuronidase that...
157.
?-Glucuronidase Mutants of the Nematode CAENORHABDITIS ELEGANS - Sebastiano, Marisa; D'Alessio, Marina; Bazzicalupo, Paolo
Using a screening procedure that is based on a histochemical stain for the enzyme ?-glucuronidase, we have isolated several mutants of the nematode Caenorhabditis elegans affected in ?-glucuronidase activity. All of the mutations fall into one complementation group and identify a new gene, gus-1, which has been mapped on the right arm of linkage group I (LG I), 1.1 map units to the left of unc-54. The mutants have no visible phenotype, and their viabilities and fertilities are unaffected. Linked revertants of two of the mutations have been isolated. They restore enzyme activity to almost wild-type levels; the ?-glucuronidase that...
158.
Radiation Effects In Nematodes: Results From Experiments - Nelson Schubert Richards; G. A. Nelson; W. Schubert; G. A. Kazarians; G. F. Richards; E. V. Bcnton; E. R. Bcntoni; Iiardware Descrifhon; Metjjods
The nematode was exposed to natural space radiation using the ESA facility aboard on Laboratory 1, STS-42. For the major objective dormant animals were suspended in buffer or on agar or immobilized next to CR-39 plastic nuclear track to correlate of HZE particles with genetic events. This configuration was used to isolate mutations in a set of 350 essential genes as as in the uric-22 structural gene. From flight samples 13 mutants in the uric-22 gene were isolated along with 53 lethal mutations from regions balanced by a eTl Preliminary analysis suggests that mutants from worms correlated with specific cosmic...
159.
Plant parasitic nematodes associated with olive in countries bordering the mediterranean sea. - Vovlas, Nicola; Castillo, Pablo; Rapoport, Hava F.; Jiménez-Díaz, Rafael M.
In countries bordering the Mediterranean sea, olive trees serve as host to a fairly high number of plant parasitic nematodes. Several of these nematodes are sedentary endoparasitic forms, many of which are recognised as pathogens to olive. Distribution, pathogenicity and host-relationships, are discussed. Currently, measures for practical nematode control in olive are limited to production nematode-free propagating material.
160.
Sterol biosynthesis in the free-living nematode Panagrellus redivivus - Willett, James D.; Downey, William L.
The fate of the known sterol precursor squalene 2,3-oxide was investigated in the free-living nematode Panagrellus redivivus. The nematodes were cultured axenically in the presence of [4-3H]squalene 2,3-oxide. Radioactivity was found in the total lipids of the isolated nematodes. Essentially all of the radioactivity encountered in the total lipids was found in the non-saponifiable fraction. The components present in the non-saponifiable fraction were separated and isolated by t.l.c. Three labelled components were identified by a combination of t.l.c., g.l.c. and mass spectroscopy. It is established that P. redivivus has the capacity for biosynthesis of lanosterol. No labelled C27 sterols could...
141.
