scholarly journals Nematophagous fungus Arthrobotrys oligospora mimics olfactory cues of sex and food to lure its nematode prey

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Yen-Ping Hsueh ◽  
Matthew R Gronquist ◽  
Erich M Schwarz ◽  
Ravi David Nath ◽  
Ching-Han Lee ◽  
...  
Keyword(s):  
Nematophagous Fungus ◽  
Rna Seq ◽  
Food Cues ◽  
Arthrobotrys Oligospora ◽  
Predator Prey ◽  
Mass Spectral ◽  
C Elegans ◽  
Multiple Receptors ◽  
Caenorhabditis Species ◽  
Chromatographic Mass

To study the molecular basis for predator-prey coevolution, we investigated how Caenorhabditis elegans responds to the predatory fungus Arthrobotrys oligospora. C. elegans and other nematodes were attracted to volatile compounds produced by A. oligospora. Gas-chromatographic mass-spectral analyses of A. oligospora-derived volatile metabolites identified several odors mimicking food cues attractive to nematodes. One compound, methyl 3-methyl-2-butenoate (MMB) additionally triggered strong sex- and stage-specific attraction in several Caenorhabditis species. Furthermore, when MMB is present, it interferes with nematode mating, suggesting that MMB might mimic sex pheromone in Caenorhabditis species. Forward genetic screening suggests that multiple receptors are involved in sensing MMB. Response to fungal odors involves the olfactory neuron AWCs. Single-cell RNA-seq revealed the GPCRs expressed in AWC. We propose that A. oligospora likely evolved the means to use olfactory mimicry to attract its nematode prey through the olfactory neurons in C. elegans and related species.

Electron capture gas-liquid chromatographic-mass spectral identification of acids produced by Neisseria meningitidis in a defined medium

1979 ◽  
Vol 9 (1) ◽  
pp. 97-102
Author(s):  
C C Alley ◽  
J B Brooks ◽  
D S Kellogg
Keyword(s):  
Liquid Chromatography ◽  
Neisseria Meningitidis ◽  
Electron Capture ◽  
Defined Medium ◽  
Gas Liquid Chromatography ◽  
Mass Spectral ◽  
Spectral Identification ◽  
Acid Metabolites ◽  
Liquid Chromatographic ◽  
Chromatographic Mass

The acid metabolites and the cellular fatty acids of three strains of Neisseria meningitidis grown in a chemically defined liquid medium were determined with computerized frequency-pulsed electron capture gas-liquid chromatography. Five acids not previously reported were subsequently identified: isobutyric, octanoic, decenoic (C10:1), dodecenoic (C12:1), and tetradecenoic (C14:1). These acids were produced during active metabolism and were not detected as cellular constituents. The frequency-pulsed electron capture gas-liquid chromatography methods which we used provide a rapid, reliable, sensitive means of detecting both these and other metabolic and cellular acids in spent culture medium.

scholarly journals Global accumulation of circRNAs during aging in Caenorhabditis elegans

2017 ◽  
Author(s):  
Mariela Cortés-López ◽  
Matthew Gruner ◽  
Daphne A. Cooper ◽  
Hannah N. Gruner ◽  
Alexandru-Ioan Voda ◽  
...  
Keyword(s):  
Global Scale ◽  
Circular Rnas ◽  
Rna Seq ◽  
Aging Research ◽  
C Elegans ◽  
Fourth Larval Stage ◽  
Functional Consequences ◽  
Exceptional Stability ◽  
Massive Accumulation

SummaryCircular RNAs (CircRNAs) are a newly appreciated class of RNAs that lack free 5´ and 3´ ends, are expressed by the thousands in diverse forms of life, and are mostly of enigmatic function. Ostensibly due to their resistance to exonucleases, circRNAs are known to be exceptionally stable. Here, we examined the global profile of circRNAs in C. elegans during aging by performing ribo-depleted total RNA-seq from the fourth larval stage (L4) through 10-day old adults. Using stringent bioinformatic criteria and experimental validation, we annotated 1,166 circRNAs, including 575 newly discovered circRNAs. These circRNAs were derived from 797 genes with diverse functions, including genes involved in the determination of lifespan. A massive accumulation of circRNAs during aging was uncovered. Many hundreds of circRNAs were significantly increased among the aging time-points and increases of select circRNAs by over 40-fold during aging were quantified by qRT-PCR. The age-accumulation of circRNAs was not accompanied by increased expression of linear RNAs from the same host genes. We attribute the global scale of circRNA age-accumulation to the high composition of postmitotic cells in adult C. elegans, coupled with the high resistance of circRNAs to decay. These findings suggest that the exceptional stability of circRNAs might explain age-accumulation trends observed from neural tissues of other organisms, which also have a high composition of post-mitotic cells. Given the suitability of C. elegans for aging research, it is now poised as an excellent model system to determine if there are functional consequences of circRNA accumulation during aging.

Combined Gas-Liquid Chromatographic Mass Spectrometric Analysis of Some Commercial Aryl Phosphate Oils

1978 ◽  
Vol 61 (2) ◽  
pp. 266-271
Author(s):  
Padmakar G Deo ◽  
Philip H Howard
Keyword(s):  
Fire Retardant ◽  
Phosphate Esters ◽  
Spectrometric Analysis ◽  
Gas Liquid Chromatography ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Hydraulic Fluids ◽  
Alkyl Phenols ◽  
Liquid Chromatographic ◽  
Chromatographic Mass

Abstract Five commercial samples of synthetic aryl phosphate oils, which are widely used as fire retardant hydraulic fluids and as flame retardant plasticizers, have been analyzed by combined gas-liquid chromatography/mass spectrometry (GLC/MS). Each sample contained at least 4 isomers of aryl phosphate esters. The peaks were identified by a close examination of the mass spectral data and, wherever possible, by comparing retention times of the peaks with those of either the purchased or synthesized compounds. One aryl phosphate hydraulic fluid contained a small amount of a hydrocarbon. The results indicate that most of the aryl phosphate esters in the commercial samples were formed from phenol, cresols, xylenols, and other alkyl phenols. No free phenols could be detected in the samples analyzed.

Characterization of Drinking Water Odour Arising from Spring Thaw for an Ice-Covered Upland River Source

1992 ◽  
Vol 25 (2) ◽  
pp. 65-72 ◽  
Author(s):  
S. E. Hrudey ◽  
D. Rector ◽  
N. Motkosky
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Samples ◽  
Raw Water ◽  
Mass Spectral ◽  
The North ◽  
Water Conditions ◽  
Biogenic Source ◽  
Chromatographic Mass

Recurring odour events during spring thaw in the North Saskatchewan River led to a program to characterize contributing odour agents. Raw and treated water samples were adsorbed on granular activated carbon which was then exhaustively solvent extracted. The solvent concentrates were subjected to a Chromatographie sniffing procedure combined with gas chromatographic-mass spectral analyses. Geosmin and 2-methylisoborneol were identified by sensory and analytical means as likely major contributors to the raw water odour. Benzaldehyde, camphor and dihydroactinidiolide were other relevant compounds identified. Given the near freezing water conditions at the time of the odour event, the biogenic source of the odour agents remains a subject for investigation.

scholarly journals Composition of the Essential Oil of Wild Growing Artemisia vulgaris from Erie, Pennsylvania

2012 ◽  
Vol 7 (5) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Jack D. Williams ◽  
Ayman M. Saleh ◽  
Dom N. Acharya
Keyword(s):  
United States ◽  
Essential Oil ◽  
The United States ◽  
Artemisia Vulgaris ◽  
Mass Spectral Analysis ◽  
Mass Spectral ◽  
Aerial Parts ◽  
Germacrene D ◽  
Leaf Oil ◽  
Chromatographic Mass

Essential Oil from wild growing Artemisia vulgaris L. originating in Erie, Pennsylvania was obtained by hydrodistillation of the aerial parts of the plant. Gas chromatographic-mass spectral analysis was used to identify the major volatiles present. Up to 22 components were detected in the essential oils. Germacrene D (25%), Caryophyllene (20%), α-Zingiberene (15%) and Borneol (11%) represent the major components of leaf oil, while the buds were rich in 1,8-Cineole (32%), Camphor (16%), Borneol (9%), and Caryophyllene (5%). trans-2-Hexenal was also detected in the aerial parts of the plant. α-Zingiberene and trans-2-Hexenal have not been previously reported for Artemisia vulgaris L. The major analytes are compared to those from Artemisia vulgaris L, originating outside of the United States.

Carbohydrate/lectin interactions between the nematophagous fungus,Arthrobotrys oligospora, and the infective juveniles ofTrichostrongylus colubriformis(Nematoda)

Parasitology ◽  
1990 ◽  
Vol 101 (1) ◽  
pp. 101-106 ◽  
Author(s):  
D. A. Wharton ◽  
D. S. Murray
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Recognition System ◽  
Nematophagous Fungus ◽  
Infective Juvenile ◽  
Carbohydrate Binding ◽  
Slow Process ◽  
Arthrobotrys Oligospora ◽  
Inner Surface ◽  
Lectin Binding Sites

SUMMARYRemoval of the sheath of the ensheathed infective juvenile ofTrichostrongylus colubriformisprevents capture by the nematophagous fungusArthrobotrys oligospora. Exposure of the trap hyphae to a variety of saccharides, which may block a recognition system based on lectin/carbohydrate binding, failed to prevent capture but some saccharides did inhibit penetration and invasion by the fungus. Capture and penetration thus appear to be two distinct processes with capture being less specific than penetration. Carbohydrate residues were absent from the outer surface of the cuticle and the sheath but were present on the inner surface of the sheath. The limited accessibility of these lectin-binding sites may explain the slow process of infection of the infective juvenile by the fungus. The sheath does not protect the infective juvenile against attack by this nematophagous fungus.

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