Acetylcholine receptor molecules of the nematode Caenorhabditis elegans

Free-living nematodes may harbor, protect, and disperse bacteria, including those ingested and passed in viable form in feces. These nematodes are potential vectors for human pathogens and may play a role in foodborne diseases associated with fruits and vegetables eaten raw. In this study, we evaluated the associations between a free-living soil nematode, Caenorhabditis elegans, and Escherichia coli, an avirulent strain of Salmonella Typhimurium, Listeria welshimeri, and Bacillus cereus. On an agar medium, young adult worms quickly moved toward colonies of all four bacteria; over 90% of 3-day-old adult worms entered colonies within 16 min after inoculation. After 48 h, worms moved in and out of colonies of L. welshimeri and B. cereus but remained associated with E. coli and Salmonella Typhimurium colonies for at least 96 h. Young adult worms fed on cells of the four bacteria suspended in K medium. Worms survived and reproduced with the use of nutrients derived from all test bacteria, as determined for eggs laid by second-generation worms after culturing for 96 h. Development was slightly slower for worms fed gram-positive bacteria than for worms fed gram-negative bacteria. Worms that fed for 24 h on bacterial lawns formed on tryptic soy agar dispersed bacteria over a 3-h period when they were transferred to a bacteria-free agar surface. The results of this study suggest that C. elegans and perhaps other free-living nematodes are potential vectors for both gram-positive and gram-negative bacteria, including foodborne pathogens in soil.

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Tc8, a Tourist-like Transposon in Caenorhabditis elegans

Genetics ◽

10.1093/genetics/158.3.1081 ◽

2001 ◽

Vol 158 (3) ◽

pp. 1081-1088 ◽

Cited By ~ 2

Author(s):

Quang Hien Le ◽

Kime Turcotte ◽

Thomas Bureau

Keyword(s):

Caenorhabditis Elegans ◽

Expressed Sequence Tags ◽

Large Family ◽

Insertion Sequences ◽

Normal Plant ◽

Nematode Caenorhabditis Elegans ◽

Plant Genomes ◽

Plant Genes ◽

Expressed Sequence ◽

Eukaryotic Genomes

Abstract Members of the Tourist family of miniature inverted-repeat transposable elements (MITEs) are very abundant among a wide variety of plants, are frequently found associated with normal plant genes, and thus are thought to be important players in the organization and evolution of plant genomes. In Arabidopsis, the recent discovery of a Tourist member harboring a putative transposase has shed new light on the mobility and evolution of MITEs. Here, we analyze a family of Tourist transposons endogenous to the genome of the nematode Caenorhabditis elegans (Bristol N2). One member of this large family is 7568 bp in length, harbors an ORF similar to the putative Tourist transposase from Arabidopsis, and is related to the IS5 family of bacterial insertion sequences (IS). Using database searches, we found expressed sequence tags (ESTs) similar to the putative Tourist transposases in plants, insects, and vertebrates. Taken together, our data suggest that Tourist-like and IS5-like transposons form a superfamily of potentially active elements ubiquitous to prokaryotic and eukaryotic genomes.

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Sperm Competition in the Absence of Fertilization in Caenorhabditis elegans

Genetics ◽

10.1093/genetics/152.1.201 ◽

1999 ◽

Vol 152 (1) ◽

pp. 201-208 ◽

Cited By ~ 2

Author(s):

Andrew Singson ◽

Katherine L Hill ◽

Steven W L’Hernault

Keyword(s):

Caenorhabditis Elegans ◽

Sperm Competition ◽

Sperm Function ◽

Sperm Precedence ◽

Wild Type ◽

Nematode Caenorhabditis Elegans ◽

C Elegans ◽

Normal Sperm ◽

Self Fertilization ◽

Competition Assays

Abstract Hermaphrodite self-fertilization is the primary mode of reproduction in the nematode Caenorhabditis elegans. However, when a hermaphrodite is crossed with a male, nearly all of the oocytes are fertilized by male-derived sperm. This sperm precedence during reproduction is due to the competitive superiority of male-derived sperm and results in a functional suppression of hermaphrodite self-fertility. In this study, mutant males that inseminate fertilization-defective sperm were used to reveal that sperm competition within a hermaphrodite does not require successful fertilization. However, sperm competition does require normal sperm motility. Additionally, sperm competition is not an absolute process because oocytes not fertilized by male-derived sperm can sometimes be fertilized by hermaphrodite-derived sperm. These results indicate that outcrossed progeny result from a wild-type cross because male-derived sperm are competitively superior and hermaphrodite-derived sperm become unavailable to oocytes. The sperm competition assays described in this study will be useful in further classifying the large number of currently identified mutations that alter sperm function and development in C. elegans.

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Genetic, Behavioral and Environmental Determinants of Male Longevity in Caenorhabditis elegans

Genetics ◽

10.1093/genetics/154.4.1597 ◽

2000 ◽

Vol 154 (4) ◽

pp. 1597-1610 ◽

Cited By ~ 1

Author(s):

David Gems ◽

Donald L Riddle

Keyword(s):

Caenorhabditis Elegans ◽

Life Span ◽

Wild Type ◽

Neuronal Function ◽

Nematode Caenorhabditis Elegans ◽

Wild Isolate ◽

Young Males ◽

C Elegans ◽

Single Sex ◽

Solitary Males

Abstract Males of the nematode Caenorhabditis elegans are shorter lived than hermaphrodites when maintained in single-sex groups. We observed that groups of young males form clumps and that solitary males live longer, indicating that male-male interactions reduce life span. By contrast, grouped or isolated hermaphrodites exhibited the same longevity. In one wild isolate of C. elegans, AB2, there was evidence of copulation between males. Nine uncoordinated (unc) mutations were used to block clumping behavior. These mutations had little effect on hermaphrodite life span in most cases, yet many increased male longevity even beyond that of solitary wild-type males. In one case, the neuronal function mutant unc-64(e246), hermaphrodite life span was also increased by up to 60%. The longevity of unc-4(e120), unc-13(e51), and unc-32(e189) males exceeded that of hermaphrodites by 70–120%. This difference appears to reflect a difference in sex-specific life span potential revealed in the absence of male behavior that is detrimental to survival. The greater longevity of males appears not to be affected by daf-2, but is influenced by daf-16. In the absence of male-male interactions, median (but not maximum) male life span was variable. This variability was reduced when dead bacteria were used as food. Maintenance on dead bacteria extended both male and hermaphrodite longevity.

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Reproductive toxicity and underlying mechanisms of di(2-ethylhexyl) phthalate in nematode Caenorhabditis elegans

Journal of Environmental Sciences ◽

10.1016/j.jes.2020.12.016 ◽

2021 ◽

Vol 105 ◽

pp. 1-10

Author(s):

Jingjing Li ◽

Man Qu ◽

Mei Wang ◽

Ying Yue ◽

Zhaofang Chen ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Reproductive Toxicity ◽

Nematode Caenorhabditis Elegans ◽

Underlying Mechanisms ◽

Ethylhexyl Phthalate

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Effect of a Neuropeptide Gene on Behavioral States in Caenorhabditis elegans Egg-Laying

Genetics ◽

10.1093/genetics/154.3.1181 ◽

2000 ◽

Vol 154 (3) ◽

pp. 1181-1192 ◽

Cited By ~ 2

Author(s):

Laura E Waggoner ◽

Laura Anne Hardaker ◽

Steven Golik ◽

William R Schafer

Keyword(s):

Caenorhabditis Elegans ◽

Active Phase ◽

Egg Laying ◽

Sensory Cues ◽

Nematode Caenorhabditis Elegans ◽

Inactive State ◽

Recessive Mutations ◽

Inactive Phase ◽

Behavioral States ◽

Stimulation Of

Abstract Egg-laying behavior in the nematode Caenorhabditis elegans involves fluctuation between alternative behavioral states: an inactive state, during which eggs are retained in the uterus, and an active state, during which eggs are laid in bursts. We have found that the flp-1 gene, which encodes a group of structurally related neuropeptides, functions specifically to promote the switch from the inactive to the active egg-laying state. Recessive mutations in flp-1 caused a significant increase in the duration of the inactive phase, yet egg-laying within the active phase was normal. This pattern resembled that previously observed in mutants defective in the biosynthesis of serotonin, a neuromodulator implicated in induction of the active phase. Although flp-1 mutants were sensitive to stimulation of egg-laying by serotonin, the magnitude of their serotonin response was abnormally low. Thus, the flp-1-encoded peptides and serotonin function most likely function in concert to facilitate the onset of the active egg-laying phase. Interestingly, we observed that flp-1 is necessary for animals to down-regulate their rate of egg-laying in the absence of food. Because flp-1 is known to be expressed in interneurons that are postsynaptic to a variety of chemosensory cells, the FLP-1 peptides may function to regulate the activity of the egg-laying circuitry in response to sensory cues.

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