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[
Nematology,
1999]
The secondary metabolites, 3,5-dihydroxy-4-isopropylstilbene (ST) and indole, from the culture filtrate of Photorhabdus luminescens MD, were shown to have nematicidal properties. ST caused nearly 100% mortality of 54 and adults of Aphelenchoides rhytium, Bursaphelenchus spp. and Caenorhabditis elegans at 100 mu g/ml, but had no effect on J2 of Meloidogyne incognita or infective juveniles (IJ) of Heterorhabditis megidis at 200 mu g/ml. Indole was lethal to several nematode species at 300 mu g/ml, and caused a high percentage of Bursaphelenchus spp. (54 and adults), M, incognita (J2) and Heterorhabditis spp. (IJ) to be paralysed at 300, 100 and 400 mu g/ml, respectively. Both ST and indole inhibited egg hatch of M, incognita. ST repelled IJ of some Steinernema spp. but not IJ of Heterorhabditis spp., and indole repelled IJ of some species of both Steinernema and Heterorhabditis. ST, but not indole, was produced in nematode-infected larval Galleria mellonella. after 24 h infection.
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[
Proc Biol Sci,
2014]
Polyphenisms can be adaptations to environments that are heterogeneous in space and time, but to persist they require conditional-specific advantages. The nematode Pristionchus pacificus is a facultative predator that displays an evolutionarily conserved polyphenism of its mouthparts. During development, P. pacificus irreversibly executes either a eurystomatous (Eu) or stenostomatous (St) mouth-form, which differ in the shape and number of movable teeth. The Eu form, which has an additional tooth, is more complex than the St form and is thus more highly derived relative to species lacking teeth. Here, we investigate a putative fitness trade-off for the alternative feeding-structures of P. pacificus. We show that the complex Eu form confers a greater ability to kill prey. When adults were provided with a prey diet, Eu nematodes exhibited greater fitness than St nematodes by several measures, including longevity, offspring survival and fecundity when followed by bacterial feeding. However, the two mouth-forms had similar fecundity when fed ad libitum on bacteria, a condition that would confer benefit on the more rapidly developing St form. Thus, the two forms show conditional fitness advantages in different environments. This study provides, to our knowledge, the first functional context for dimorphism in a model for the genetics of plasticity.
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J Ethnopharmacol,
2001]
Five aqueous extracts from three plant species, i.e., dried husks (HX), dried seeds (SX) and dried leaves (LX) of Xylocarpus granatum (Meliaceae), dried stems (ST) of Tinospora crispa (Menispermaceae) and dried leaves (LA) of Andrographis paniculata (Acanthaceae) were tested in vitro against adult worms of subperiodic Brugia malayi. The relative movability (RM) value of the adult worms over the 24-h observation period was used as a measure of the antifilarial activity of the aqueous extracts. SX extract of X. granatum demonstrated the strongest activity, followed by the LA extract of A. paniculata, ST extract of T. crispa, HX extract and LX extract of X. granatum.
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[
Microorganisms,
2020]
The design of multiscale strategies integrating in vitro and in vivo models is necessary for the selection of new probiotics. In this regard, we developed a screening assay based on the investigation of the potential of yeasts from cheese as probiotics against the pathogen <i>Salmonella</i> Typhimurium UPsm1 (ST). Two yeasts isolated from raw-milk cheese (<i>Saccharomyces cerevisiae</i> 16, Sc16; <i>Debaryomyces hansenii</i> 25, Dh25), as well as <i>S. cerevisiae</i> subspecies <i>boulardii</i> (CNCM I-1079, Sb1079), were tested against ST by applying in vitro and in vivo tests. Adherence measurements to Caco-2 and HT29-MTX intestinal cells indicated that the two tested cheese yeasts presented a better adhesion than the probiotic Sb1079 as the control strain. Further, the Dh25 was the cheese yeast most likely to survive in the gastrointestinal tract. What is more, the modulation of the TransEpithelial Electrical Resistance (TEER) of differentiated Caco-2 cell monolayers showed the ability of Dh25 to delay the deleterious effects of ST. The influence of microorganisms on the in vivo model <i>Caenorhabditis elegans</i> was evaluated by measuring the longevity of the worm. This in vivo approach revealed that this yeast increased the worm's lifespan and protected it against ST infection, confirming that this in vivo model can be useful for screening probiotic cheese yeasts.
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Parasitol Today,
1993]
Arrested development dramatically alters the life history of some species of soil-transmitted nematodes and elicits profound variations in the epidemiology of the infections they cause. Here, Peter Hotez, John Hawdon and Gerhard Schad show how an understanding of the cellular and molecular bases of arrested development may lead to new approaches for the control of ancylostomiasis and related infections.
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[
J Neurogenet
]
John Sulston changed the way we do science, not once, but three times - initially with the complete cell lineage of the nematode <i>Caenorhabditis elegans</i>, next with completion of the genome sequences of the worm and human genomes and finally with his strong and active advocacy for open data sharing. His contributions were widely recognized and in 2002 he received the Nobel Prize in Physiology and Medicine.
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[
J Neurogenet
]
A slide taped to a window at the Woods Hole Marine Biology Laboratory was my first introduction to the touch receptor neurons of the nematode <i>Caenorhabditis elegans</i>. Studying these cells as a postdoc with Sydney Brenner gave me a chance to work with John Sulston on a fascinating set of neurons. I would never have guessed then that 43 years later I would still be excited about learning their secrets.
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[
Development,
2018]
John Sulston, a pioneer in the developmental studies of the nematode <i>C. elegans</i> who went on to spearhead the sequencing of the genome of this organism and ultimately the human genome, died on 6th March 2018, shortly after being diagnosed with stomach cancer. Here, I reflect on John's life and work, with a particular focus on his time working on the developmental genetics and lineage of <i>C. elegans</i><i>.</i>
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Biomed Chromatogr,
2005]
An improved method for proteomics studies, which includes the fl uorogenic derivertization of protein mixtures with 7-chloro-4-(dimethylaminoethylaminosulfonyl)-2,1,3-benzoxadiazole (DAABD-Cl), followed by HPLC isolation, enzymatic digestion and ideti fi cation of the derivatized proteins by HPLC-electrospray ionization (ESI)-MS/MS with the probability-based protein identi fi cation algorithm, identi fi ed 103 proteins in the soluble extract (10 microg protein) of Caenorhabditis elegans. Copyright (c) 2005 John Wiley & Sons, Ltd.
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CBE Life Sci Educ,
2008]
The skill set required of biomedical researchers continues to grow and evolve as biology matures as a natural science. Science necessitates creative yet critical thinking, persuasive communication skills, purposeful use of time, and adeptness at the laboratory bench. Teaching these skills can be effectively accomplished in an inquiry-based, active-learning environment at a primarily undergraduate institution. Cell Biology Techniques, an upper-level cell biology laboratory course at St. John Fisher College, features two independent projects that take advantage of the biology of the nematode Caenorhabditis elegans, a premier yet simple model organism. First, students perform a miniature epigenetic screen for novel phenotypes using RNA interference. The results of this screen combined with literature research direct students toward a singe gene that they attempt to subclone in the second project. The biology of the chosen gene/protein also becomes an individualized focal point with respect to the content of the laboratory. Progress toward course goals is evaluated using written, oral, and group-produced assignments, including a concept map. Pre- and postassessment indicates a significant increase in the understanding of broad concepts in cell biological research.