01501nas a2200193   4500008004100000020001400041245015100055210006900206260000800275300001200283490000800295520087100303100001701174700002101191700001701212700001601229700001601245856004601261       1994                        eng d  a0301-556400aTISSUE TREATMENT FOR WHOLE-MOUNT INTERNAL LECTIN STAINING IN THE NEMATODES CAENORHABDITIS-ELEGANS, PANAGROLAIMUS-SUPERBUS AND ACROBELOIDES-MAXIMUS0 aTISSUE TREATMENT FOR WHOLEMOUNT INTERNAL LECTIN STAINING IN THE   cJun  a379-3840 v1013 aFour different fixation schemes, using ten fluorescent-labelled lectins, were investigated for whole mount internal staining of three rhabditid nematodes: Caenorhabditis elegans, Panagrolaimus superbus and Acrobeloides maximus. Acetone-only fixation was found to give strong and reproducible staining, which could be prevented either by periodate treatment of the organisms or by specific inhibitory sugars of the lectins under investigation. Whereas the use of either phosphate or TRIS buffers had no effect on the staining pattern or the fluorescence intensity, the incubation time as well as the in cubation temperature affected the staining reaction. The best results were obtained upon overnight incubation at 4 degrees C: the lectin staining could be inhibited in all cases, except for the intestinal brush border of C. elegans by the lectin of Lens culinaris.1 aBorgonie, G.1 aVanDriessche, E.1 aLink, C., D.1 aDeWaele, D.1 aCoomans, A.  uhttps://nematodes.myspecies.info/node/29201366nas a2200193   4500008004100000020001400041245016500055210006900220300001200289490000700301520072500308100001701033700001501050700001401065700001501079700001601094700001601110856004601126       1996                        eng d  a1164-557100aEffect of nematicidal Bacillus thuringiensis strains on free-living nematodes .2. Ultrastructural analysis of the intoxication process in Caenorhabditis elegans0 aEffect of nematicidal Bacillus thuringiensis strains on freelivi  a407-4140 v193 aTransmission electron microscopy is used to describe the intoxication in Caenorhabditis elegans, feeding on toxic spore/crystals of Bacillus thuringiensis. The toxin acts directly against the intestine, first by affecting the anteriormost ring of four intestinal cells. Over a period of 12 hours, these cells lose much of their volume, the microvilli regress slowly, several cell organelles undergo dramatic change and are ultimately destroyed. No rupture of the apical intestinal cell membrane is observed. Non-intestinal tissues seem unaffected. This study indicates considerable ultrastructural differences in the mode of action between the nematicidal toxin and the insecticidal crystal toxins from B. thuringiensis.1 aBorgonie, G.1 aClaeys, M.1 aLeyns, F.1 aArnaut, G.1 aDeWaele, D.1 aCoomans, A.  uhttps://nematodes.myspecies.info/node/26001673nas a2200193   4500008004100000020001400041245013200055210006900187300001200256490000700268520106500275100001701340700001501357700001401372700001501386700001601401700001601417856004601433       1996                        eng d  a1164-557100aEffect of a nematicidal Bacillus thuringiensis strain on free-living nematodes .3. Characterization of the intoxication process0 aEffect of a nematicidal Bacillus thuringiensis strain on freeliv  a523-5280 v193 aThe toxicity of Bacillus thuringiensis is temperature sensitive. Incubation of Caenorhabditis elegans with nematicidal B. thuringiensis strains at 16, 20, and 25 degrees C shows that toxicity decreases as temperature declines. At 16 degrees C, toxicity is completely lost, while it is maximal at 25 degrees C. Toxicity is pH sensitive and is significantly reduced when nematodes are incubated with the weak bases NH4Cl, chloroquine, acridine orange, methyl red, and neutral red. Based on these results, we proposed the hypothesis that the nematicidal factor is effectively internalized into the intestinal cells, a sharp deviation from the insecticidal B. thuringiensis toxins acting at the level of the brush border membrane. Although the absence of purified toxin prevents a more definitive elucidation of the mode of action, the results of this third and final part of this series of publications convincingly indicate that nematicidal B. thuringiensis do not hold the same promise as a biological control agent as the insecticidal B. thuringiensis strains.1 aBorgonie, G.1 aClaeys, M.1 aLeyns, F.1 aArnaut, G.1 aDeWaele, D.1 aCoomans, A.  uhttps://nematodes.myspecies.info/node/26102028nas a2200193   4500008004100000020001400041245022500055210006900280300001200349490000700361520132700368100001701695700001501712700001401727700001501741700001601756700001601772856004601788       1996                        eng d  a1164-557100aEffect of nematicidal Bacillus thuringiensis strains on free-living nematodes .1. Light microscopic observations, species and biological stage specificity and identification of resistant mutants of Caenorhabditis elegans0 aEffect of nematicidal Bacillus thuringiensis strains on freelivi  a391-3980 v193 aLight-microscopic observations of the toxic action of Bacillus thuringiensis spore/crystals reveals that, in Caenorhabditis elegans, the intestine is destroyed in two stages over a period of 24 h. The anterior ring of four cells is the first and foremost target. Observations indicate that the intestine is the only tissue being destroyed. Screening of fourteen additional rhabditid nematode species against three nematicidal B. thuringiensis strains active against C. elegans, resulted in only one additional sensitive nematode species, and indicates a high species specificity of the nematicidal factor. However, in contrast to insect-specific B. thuringiensis toxins, the nematicidal toxin exhibits low developmental stage specificity against C. elegans; all developmental stages, including adult nematodes are sensitive. Moreover, sensitivity increases as development proceeds. Using ethyl methyl sulfonate induced mutagenesis two mutants of C. elegans have been recovered, exhibiting reduced sensitivity of up to 50 % against one of the nematicidal strains. Moreover, one of the mutants exhibited cross-resistance to a second nematicidal B. thuringiensis strain against which it was not screened. Preliminary data indicate that the reduced sensitivity in the mutants is not due to reduced pharyngeal pumping activity.1 aBorgonie, G.1 aClaeys, M.1 aLeyns, F.1 aArnaut, G.1 aDeWaele, D.1 aCoomans, A.  uhttps://nematodes.myspecies.info/node/26201695nas a2200205   4500008004100000020001400041245010100055210006900156260000800225300001000233490000700243520109400250100001701344700002101361700001401382700001501396700001601411700001601427856004601443       1995                        eng d  a0022-201100aGERMINATION OF BACILLUS-THURINGIENSIS SPORES IN BACTERIOPHAGOUS NEMATODES (NEMATODA, RHABDITIDA)0 aGERMINATION OF BACILLUSTHURINGIENSIS SPORES IN BACTERIOPHAGOUS N  cJan  a61-670 v653 aDuring screening of Bacillus thuringiensis isolates for nematicidal activity it was observed that spores of B. thuringiensis germinated in the intestine of bacteriophagous nematodes in the presence of antibiotics. This phenomenon was studied more closely by scanning electron microscopy. The nematodes were fed with bacterial spore-crystal mixtures in axenic culture medium supplemented with tetracyclin and chloramphenicol. Germination of spores was rare but was more frequently observed in Panagrellus redivivus than in other nematode species investigated. Germination of spores in the nematode intestine resulted in the colonization of the entire nematode within 24 hr. Crude nematode tissue preparations supported germination and subsequent growth of B. thuringiensis spores and vegetative cells. The mechanism for the loss of antibiotic activity in the nematode intestine is unknown. Since B. thuringiensis requires a nutrient-rich environment for reproduction, e.g., a cadaver, bacteriophagous nematodes may serve as suitable hosts for B. thuringiensis. (C) 1995 Academic Press, Inc.1 aBorgonie, G.1 aVandriessche, R.1 aLeyns, F.1 aArnaut, G.1 aDeWaele, D.1 aCoomans, A.  uhttps://nematodes.myspecies.info/node/27401636nas a2200181   4500008004100000020001400041245011400055210006900169300001200238490000700250520106700257100001701324700001501341700002001356700001601376700001601392856004601408       1995                        eng d  a1164-557100aPRESENCE OF PERITROPHIC-LIKE MEMBRANES IN THE INTESTINE OF 3 BACTERIOPHAGOUS NEMATODES (NEMATODA, RHABDITIDA)0 aPRESENCE OF PERITROPHICLIKE MEMBRANES IN THE INTESTINE OF 3 BACT  a227-2330 v183 aUltrastructural analysis shows the presence of membranes originating at the top of the intestinal microvilli, along the entire length of the intestine in the three rhabditid nematodes Caenorhabditis elegans, Panagrolaimus superbus and Acrobeloides maximus. The membranes allow the passage of fluorescein isothiocyanate, methyl red, neutral red and acridine orange, but allow only sparse passage of ferritin molecules. Upon the introduction of a sublethal dose of sodium azide, the intestinal lumen displays an increased secretion of membrane layers. Whole mount staining of the nematodes with the Solanum tuberosum and Triticum vulgare lectins, known to bind with high affinity to chitin, shows only specific binding of Solanum tuberosum lectin to the brush border in all developmental stages of C. elegans, P. superbus and A. maximus. The results reveal the presence of membranes in the intestine of three species of one of the most ancient metazoan phyla, exhibiting morphological and functional characteristics reminiscent of peritrophic membranes in insects.1 aBorgonie, G.1 aClaeys, M.1 aVanfleteren, J.1 aDeWaele, D.1 aCoomans, A.  uhttps://nematodes.myspecies.info/node/27601738nas a2200169   4500008004100000020001400041245011400055210006900169300001200238490000700250520120100257100001701458700001501475700001601490700001601506856004601522       1995                        eng d  a1164-557100aIN-VIVO AND IN-VITRO CHARACTERIZATION OF THE INTESTINE OF 15 BACTERIOPHAGOUS NEMATODES (NEMATODA, RHABDITIDA)0 aINVIVO AND INVITRO CHARACTERIZATION OF THE INTESTINE OF 15 BACTE  a115-1220 v183 aThe intestine of the fifteen free-living Rhabditida belonging to three different families was studied using three different approaches : i) using three different axenic media, cultivation of all fifteen nematode species was attempted; ii) in vivo analyses were performed by using two vital stains and one fluorescent dye and by comparing staining patterns; iii) in vitro analyses was done using the intestinal markers acid phosphatase, esterase and the lectin of Ricinus communis II. Although the nematodes can be cultured monoxenically on the same bacterium, Escherichia coli, attempts to culture the fifteen nematode species on the same axenic medium failed. Distinct differences are observed between different areas along the intestinal tract by in vivo study using stains. Similar observations were made in vitro using the intestinal marker acid phosphatase and the binding pattern of Ricinus communis II. This was less evident using esterase as a marker, since considerable non-intestinal tissue staining was evident. The data obtained indicate considerable biochemical differences in the intestinal cells between the nematode species, even if the nematode species belong to the same family.1 aBorgonie, G.1 aClaeys, M.1 aDeWaele, D.1 aCoomans, A.  uhttps://nematodes.myspecies.info/node/27701400nas a2200169   4500008004100000020001400041245016400055210006900219300001200288490000700300520081300307100001701120700001501137700001601152700001601168856004601184       1995                        eng d  a1164-557100aULTRASTRUCTURE OF THE INTESTINE OF THE BACTERIOPHAGOUS NEMATODES CAENORHABDITIS-ELEGANS, PANAGROLAIMUS SUPERBUS AND ACROBELOIDES MAXIMUS (NEMATODA, RHABDITIDA)0 aULTRASTRUCTURE OF THE INTESTINE OF THE BACTERIOPHAGOUS NEMATODES  a123-1330 v183 aThe intestine of the three free-living rhabditid nematodes Caenorhabditis elegans, Panagrolaimus superbus and Acrobeloides maximus was studied using transmission electron microscopy of sections made at three locations along the intestine. Between the three nematode species, ultrastructural differences in cellular components are minor. However, two cell types present in all three nematode species are positioned differently along the intestinal tract. Furthermore, two different types of secretions into the intestinal lumen were identified, one only at the anterior intestine, the second present along the entire length of the intestinal lumen. F-actin staining of fifteen whole-mount nematodes revealed the presence of a well developed, cross-shaped intestinal muscle, only present in Cephalobid species.1 aBorgonie, G.1 aClaeys, M.1 aDeWaele, D.1 aCoomans, A.  uhttps://nematodes.myspecies.info/node/27801393nas a2200193   4500008004100000020001400041245012600055210006900181300001200250490000700262520078200269100001701051700002101068700001701089700001501106700001601121700001601137856004601153       1997                        eng d  a1164-557100aInternal lectin binding patterns in the nematodes Caenorhabditis elegans, Panagrolaimus superbus and Acrobeloides maximus0 aInternal lectin binding patterns in the nematodes Caenorhabditis  a173-1860 v203 aUsing ten different lectins, the binding patterns were studied in three free-living rhabditid nematodes : Caenorhabditis elegans, Panagrolaimus superbus, and Acrobeloides maximus. Although all the nematode tissues showed binding by one or more of the lectins used, considerable differences were noticed between the three nematode species. Yolk, four of the coelomocytes, and the oocytes bind most often with the lectins used. Although the intestinal brush border interacts with a lot of foreign materials, it stained only with few lectins. The lectin binding pattern of the yolk indicated that, at the time of incorporation of the yolk in embryos or shortly thereafter, a processing of the yolk occurs resulting in changes in lectin-binding characteristics of the yolk protein.1 aBorgonie, G.1 aVanDriessche, E.1 aLink, C., D.1 aClaeys, M.1 aDeWaele, D.1 aCoomans, A.  uhttps://nematodes.myspecies.info/node/245