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[
Mycologia,
1936]
In Zopf's account of tha capture of nematodes by Arthrobotrys oligospora Fres. and Monosporidium repens Zopf were described, apparently for the first time, instances of a biological habit comparable in part to the carnivorous habit of insectivorous flowering plants. More recently nearly a score of additional fungi occurring in soil, in leaf mold, and in solid decaying materials generally, have been found to capture and consume nematodes in large numbers; evidently, indeed, subsisting in nature entirely through such predacious activity. By far most of these fungi are closely related to those dealt with by Zopf, being referable to a group of interrelated genera including Arthrobotrys, Trichothecium, Cephalothecium, Dactylaria, Dactylella and Monacrosporium. The relatively few nematode-capturing forms alien to this hyphomycetous series are conidial phycomycetes belonging to a Zoopagaceae, a family whose known members are mostly destructive to terricolous amoebae, some operating in parasitic, other predacious relationships. Of the few species preying on nematodes, only one, Stylopage hadra Drechsl., has hitherto been described in detail; so that the description offered herein, of a second species of like biological habit, may be of interest even in the absence of pronounced departures in morphology.
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[
Mycologia,
1944]
In several previous papers descriptive treatment was given to 22 interrelated hyphomycetes found subsisting by the capture and destruction of eelworms infesting transparent agar plate cultures started from diseased rootlets or from other decaying vegetable materials. Similar treatment is devoted herein to 3 additional fungi of like biological habit and manifestly belonging to the same predaceous series. Capture of eelworms is accomplished, in all 3 fungi, by means of adhesive bail-like hyphal loops, which, as in allied forms, may occur singly, or may be compounded into networks of variable intricacy. Two of the fungi are referred to Arthrobotrys, one being presented as a new variety, while the other is identified with a long-established though somewhat unfamiliar species of that genus. The third fungus is described as a new species of Dactylaria. In relation to a subsidiary spore form apparently connected with the new species, preliminary discussion is devoted to a delicate Trichothecium found producing stalked adhesive knob-cells.
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[
Phytopathology,
1941]
Agar plate cultures, prepared in the isolation of parasitic oomycetes from discolored roots or other decaying plant materials, often permit abundant multiplication of free-living nematodes, which then are frequently destroyed in large numbers by various predaceous and parasitic fungi. As the parasitic manner of attack, wherein infection comes about from germination of affixed or ingested spores, is shared widely among fungi, it is not surprising that the parasitic forms destructive to eelworms are rather diverse in their taxonomic relationships. Thus, while the 3 parasites that I described earlier under the binomials Euryancale sacciospora, Haptoglossa heterospora, and Meristacrum asterospermum, all belong in the Phycomycetes, they are referable to 3 different groups within that class. Ten additional species, similarly parasitic, but, from their septate vegetative mycelium, obviously belonging with the higher rather than with the lower fungi, are described herein. Important or conspicuous differences in the morphology of their conidial apparatus divide these species into 4 catagories, only one of which is represented by more than a single genus.
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[
Mycologia,
1940]
In an earlier paper was given a comparative account of 18 interrelated mucedinaceous fungi found to subsist habitually on nematodes that they capture by means of vegetative parts variously adapted for prehension. These fungi had come to light in agar cultures started from discolored rootlets or from other affected vegetable materials, and later often further planted with pinches of friable leaf mold. Similar cultures prepared as circumstances permitted during the last few years have revealed 3 additional mucedinaceous forms obviously belonging in the same series as those previously discussed, and like them observed subsisting by the capture of free-living terricolous eelworms. As the forms appear not to have been recorded hitherto in mycological literature, they are described herein as a species new to science.
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[
Journal of the Washington Academy of Sciences,
1940]
In several earlier papers comparative treatment was accorded to 24 fungi that had been observed to subsist on free-living nematodes infesting old agar cultures started from diseased rootlets or from other decaying vegetable materials. As the agar media employed were of a concentration sufficient to insure a rather firm consistency together with relative freedom from liquid water, the cultures provided approximately terrestrial rather than aquatic conditions, and therefore not only encouraged the multiplication of eelworms mainly terrestrial with respect to source and adaptation, but also permitted development of the similarly terrestrial fungi habitually destructive to them under natural conditions....
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[
Bulletin of the Torrey Botanical Club,
1946]
In 1874 Lohde briefly described a hyphomycete that he found growing parasitically on numerous eelworms belonging to a species of Anguillula. To this hyphomycete he applied the binomial Harposporium Anguillulae; the generic term then presented for the first time having reference to the crescentically curved, sickle-shaped conidia which the fungus produced terminally on delicate sterigmata arising singley from peculiar round protuberances formed laterally on the hyphal branches or hyphal prolongations that were extended from the multicellular mycelial filaments, from 2 to 4 in number, passing through the animals body....
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[
International Worm Meeting,
2019]
C. elegans is associated in nature with a species-rich, distinct microbiota, which was characterized only recently [1]. Our understanding of C. elegans microbiota function is thus still in its infancy. Here, we identify natural C. elegans microbiota isolates of the Pseudomonas fluorescens subgroup that increase C. elegans resistance to pathogen infection. We show that different Pseudomonas isolates provide paramount protection from infection with the natural C. elegans pathogen Bacillus thuringiensis through distinct mechanisms [2] . The P. lurida isolates MYb11 and MYb12 (members of the P. fluorescens subgroup) protect C. elegans against B. thuringiensis infection by directly inhibiting growth of the pathogen both in vitro and in vivo. Using genomic and biochemical approaches, we demonstrate that MYb11 and MYb12 produce massetolide E, a cyclic lipopeptide biosurfactant of the viscosin group, which is active against pathogenic B. thuringiensis. In contrast to MYb11 and MYb12, P. fluorescens MYb115-mediated protection involves increased resistance without inhibition of pathogen growth and most likely depends on indirect, host-mediated mechanisms. We are currently investigating the molecular basis of P. fluorescens MYb115-mediated protection using a multi-omics approach to identify C. elegans candidate genes involved in microbiota-mediated protection. Moreover, we are further exploring the antagonistic interactions between C. elegans microbiota and pathogens. This work provides new insight into the functional significance of the C. elegans natural microbiota and expands our knowledge of immune-protective mechanisms. 1. Zhang, F., Berg, M., Dierking, K., Felix, M.A., Shapira, M., Samuel, B.S., and Schulenburg, H. (2017). Caenorhabditis elegans as a model for microbiome research. Front. Microbiol. 8:485. 2. Kissoyan, K.A.B., Drechsler, M., Stange, E.-L., Zimmermann, J., Kaleta, C., Bode, H.B., and Dierking, K. (2019). Natural C. elegans Microbiota Protects against Infection via Production of a Cyclic Lipopeptide of the Viscosin Group. Curr. Biol. 29.
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[
BMC Genomics,
2007]
ABSTRACT: BACKGROUND: In the genome of Caenorhabditis elegans, homopolymeric poly-G/poly-C tracts (G/C tracts) exist at high frequency and are maintained by the activity of the DOG-1 protein. The frequency and distribution of G/C tracts in the genomes of C. elegans and the related nematode, C. briggsae were analyzed to investigate possible biological roles for G/C tracts. RESULTS: In C. elegans, G/C tracts are distributed along every chromosome in a non-random pattern. Most G/C tracts are within introns or are close to genes. Analysis of SAGE data showed that G/C tracts correlate with the levels of regional gene expression in C. elegans. G/C tracts are over-represented and dispersed across all chromosomes in another Caenorhabditis species, C. briggase. However, the positions and distribution of G/C tracts in C. briggsae differ from those in C. elegans. Furthermore, the C. briggsae
dog-1 ortholog CBG19723 can rescue the mutator phenotype of C. elegans
dog-1 mutants. CONCLUSIONS: The abundance and genomic distribution of G/C tracts in C. elegans, the effect of G/C tracts on regional transcription levels, and the lack of positional conservation of G/C tracts in C. briggsae suggest a role for G/C tracts in chromatin structure but not in the transcriptional regulation of specific genes.
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[
West Coast Worm Meeting,
2002]
To understand the evolution of developmental mechanisms, we are doing a comparative analysis of vulval patterning in C. elegans and C. briggsae. C. briggsae is closely related to C. elegans and has identical looking vulval morphology. However, recent studies have indicated subtle differences in the underlying mechanisms of development. The recent completion of C. briggsae genome sequence by the C. elegans Sequencing Consortium is extremely valuable in identifying the conserved genes between C. elegans and C. briggsae.
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Horng JC, Hsu HL, Nazilah KR, Wang CC, Wang TL, Wang SC, Antika TR, Chuang TH, Chrestella DJ, Wang SW, Tseng YK, Pan HC
[
J Biol Chem,
2023]
Alanyl-tRNA synthetase (AlaRS) retains a conserved prototype structure throughout its biology. Nevertheless, its C-terminal domain (C-Ala) is highly diverged and has been shown to play a role in either tRNA or DNA binding. Interestingly, we discovered that Caenorhabditis elegans cytoplasmic C-Ala (Ce-C-Ala<sub>c</sub>) robustly binds both ligands. How Ce-C-Ala<sub>c</sub> targets its cognate tRNA and whether a similar feature is conserved in its mitochondrial counterpart remain elusive. We show that the N- and C-terminal subdomains of Ce-C-Ala<sub>c</sub> are responsible for DNA and tRNA binding, respectively. Ce-C-Ala<sub>c</sub> specifically recognized the conserved invariant base G<sup>18</sup> in the D-loop of tRNA<sup>Ala</sup> through a highly conserved lysine residue, K934. Despite bearing little resemblance to other C-Ala domains, C. elegans mitochondrial C-Ala (Ce-C-Ala<sub>m</sub>) robustly bound both tRNA<sup>Ala</sup> and DNA and maintained targeting specificity for the D-loop of its cognate tRNA. This study uncovers the underlying mechanism of how C. elegans C-Ala specifically targets the D-loop of tRNA<sup>Ala</sup>.