scholarly journals Inter-generational consequences for growing Caenorhabditis elegans in liquid

2019 ◽  
Vol 374 (1770) ◽  
pp. 20180125 ◽  
Author(s):  
Itamar Lev ◽  
Roberta Bril ◽  
Yunan Liu ◽  
Lucila Inés Ceré ◽  
Oded Rechavi
Keyword(s):  
Caenorhabditis Elegans ◽  
Early Life ◽  
Epigenetic Inheritance ◽  
Evolutionary Medicine ◽  
C Elegans ◽  
Generational Effects ◽  
Large Populations ◽  
Two Generations ◽  
Generational Changes ◽  
In The Wild

In recent years, studies in Caenorhabditis elegans nematodes have shown that different stresses can generate multigenerational changes. Here, we show that worms that grow in liquid media, and also their plate-grown progeny, are different from worms whose ancestors were grown on plates. It has been suggested that C. elegans might encounter liquid environments in nature, although actual observations in the wild are few and far between. By contrast, in the laboratory, growing worms in liquid is commonplace, and often used as an alternative to growing worms on agar plates, to control the composition of the worms' diet, to starve (and synchronize) worms or to grow large populations for biochemical assays. We found that plate-grown descendants of M9 liquid medium-grown worms were longer than control worms, and the heritable effects were already apparent very early in development. We tested for the involvement of different known epigenetic inheritance mechanisms, but could not find a single mutant in which these inter-generational effects are cancelled. While we found that growing in liquid always leads to inter-generational changes in the worms’ size, trans-generational effects were found to be variable, and in some cases, the effects were gone after one to two generations. These results demonstrate that standard cultivation conditions in early life can dramatically change the worms' physiology in adulthood, and can also affect the next generations. This article is part of the theme issue ‘Developing differences: early-life effects and evolutionary medicine’.

scholarly journals Inter-generational Consequences for Growing C.elegans in Liquid

2018 ◽  
Author(s):  
Itamar Lev ◽  
Roberta Bril ◽  
Yunan Liu ◽  
Lucila Inés Ceré ◽  
Oded Rechavi
Keyword(s):  
Epigenetic Inheritance ◽  
Liquid Media ◽  
Cultivation Conditions ◽  
Intergenerational Effects ◽  
Biochemical Assays ◽  
Generational Effects ◽  
Large Populations ◽  
Generational Changes ◽  
In The Wild ◽  
Heritable Effects

AbstractIn recent years, studies in Caenorhabditis elegans nematodes have shown that different stresses can generate multigenerational changes. Here we show that worms that grow in liquid media, and also their plate-grown progeny, are different from worms whose ancestors were grown on plates. It has been suggested that C.elegans might encounter liquid environments in nature, although actual observations in the wild are few and far between. In contrast, in the lab, growing worms in liquid is commonplace, and often used as an alternative to growing worms on agar plates, to control the composition of the worms’ diet, to starve (and synchronize) worms, or to grow large populations for biochemical assays. We found that plate-grown descendants of M9 liquid media-grown worms were longer than control worms, and the heritable effects were apparent already very early in development. We tested for the involvement of different known epigenetic inheritance mechanisms, but could not find a single mutant in which these intergenerational effects are canceled. While we found that growing in liquid always leads to inter-generational changes in the worms’ size, trans-generational effects were found to be variable, and in some cases the effects were gone after 1 -2 generations. These results demonstrate that standard cultivation conditions in early life can dramatically change the worms’ physiology in adulthood, and can also affect the next generations.

scholarly journals Intergenerational Pathogen-Induced Diapause in Caenorhabditis elegans Is Modulated by mir-243

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Carolaing Gabaldón ◽  
Marcela Legüe ◽  
M. Fernanda Palominos ◽  
Lidia Verdugo ◽  
Florence Gutzwiller ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Noncoding Rna ◽  
Pathogenic Bacteria ◽  
Developmental Change ◽  
Differential Expression Analysis ◽  
Phenotypic Analysis ◽  
Content Type ◽  
C Elegans ◽  
Two Generations ◽  
Dauer Formation

ABSTRACT The interaction and communication between bacteria and their hosts modulate many aspects of animal physiology and behavior. Dauer entry as a response to chronic exposure to pathogenic bacteria in Caenorhabditis elegans is an example of a dramatic survival response. This response is dependent on the RNA interference (RNAi) machinery, suggesting the involvement of small RNAs (sRNAs) as effectors. Interestingly, dauer formation occurs after two generations of interaction with two unrelated moderately pathogenic bacteria. Therefore, we sought to discover the identity of C. elegans RNAs involved in pathogen-induced diapause. Using transcriptomics and differential expression analysis of coding and long and small noncoding RNAs, we found that mir-243-3p (the mature form of mir-243) is the only transcript continuously upregulated in animals exposed to both Pseudomonas aeruginosa and Salmonella enterica for two generations. Phenotypic analysis of mutants showed that mir-243 is required for dauer formation under pathogenesis but not under starvation. Moreover, DAF-16, a master regulator of defensive responses in the animal and required for dauer formation was found to be necessary for mir-243 expression. This work highlights the role of a small noncoding RNA in the intergenerational defensive response against pathogenic bacteria and interkingdom communication. IMPORTANCE Persistent infection of the bacterivore nematode C. elegans with bacteria such as P. aeruginosa and S. enterica makes the worm diapause or hibernate. By doing this, the worm closes its mouth, avoiding infection. This response takes two generations to be implemented. In this work, we looked for genes expressed upon infection that could mediate the worm diapause triggered by pathogens. We identify mir-243-3p as the only transcript commonly upregulated when animals feed on P. aeruginosa and S. enterica for two consecutive generations. Moreover, we demonstrate that mir-243-3p is required for pathogen-induced dauer formation, a new function that has not been previously described for this microRNA (miRNA). We also find that the transcriptional activators DAF-16, PQM-1, and CRH-2 are necessary for the expression of mir-243 under pathogenesis. Here we establish a relationship between a small RNA and a developmental change that ensures the survival of a percentage of the progeny.

scholarly journals Transgenerational Diapause as an Avoidance Strategy against Bacterial Pathogens in Caenorhabditis elegans

mBio ◽  
2017 ◽  
Vol 8 (5) ◽  
Author(s):  
M. Fernanda Palominos ◽  
Lidia Verdugo ◽  
Carolaing Gabaldon ◽  
Bernardo Pollak ◽  
Javiera Ortíz-Severín ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Behavioral Change ◽  
Pathogenic Bacteria ◽  
Behavioral Changes ◽  
Survival Strategies ◽  
Information Encoding ◽  
C Elegans ◽  
Two Generations ◽  
And Behavior ◽  
Dauer Larvae

ABSTRACT The dynamic response of organisms exposed to environmental pathogens determines their survival or demise, and the outcome of this interaction depends on the host’s susceptibility and pathogen-dependent virulence factors. The transmission of acquired information about the nature of a pathogen to progeny may ensure effective defensive strategies for the progeny’s survival in adverse environments. Environmental RNA interference (RNAi) is a systemic and heritable mechanism and has recently been linked to antibacterial and antifungal defenses in both plants and animals. Here, we report that the second generation of Caenorhabditis elegans living on pathogenic bacteria can avoid bacterial infection by entering diapause in an RNAi pathway-dependent mechanism. Furthermore, we demonstrate that the information encoding this survival strategy is transgenerationally transmitted to the progeny via the maternal germ line. IMPORTANCE Bacteria vastly influence physiology and behavior, and yet, the specific mechanisms by which they cause behavioral changes in hosts are not known. We use C. elegans as a host and the bacteria they eat to understand how microbes trigger a behavioral change that helps animals to survive. We found that animals faced with an infection for two generations could enter a hibernationlike state, arresting development by forming dauer larvae. Dauers have closed mouths and effectively avoid infection. Animals accumulate information that is transgenerationally transmitted to the next generations to form dauers. This work gives insight on how bacteria communicate in noncanonical ways with their hosts, resulting in long-lasting effects providing survival strategies to the community. IMPORTANCE Bacteria vastly influence physiology and behavior, and yet, the specific mechanisms by which they cause behavioral changes in hosts are not known. We use C. elegans as a host and the bacteria they eat to understand how microbes trigger a behavioral change that helps animals to survive. We found that animals faced with an infection for two generations could enter a hibernationlike state, arresting development by forming dauer larvae. Dauers have closed mouths and effectively avoid infection. Animals accumulate information that is transgenerationally transmitted to the next generations to form dauers. This work gives insight on how bacteria communicate in noncanonical ways with their hosts, resulting in long-lasting effects providing survival strategies to the community.

scholarly journals Caenorhabditis elegans triple null mutant lacking UDP-N-acetyl-D-glucosamine:α-3-D-mannoside β1,2-N-acetylglucosaminyltransferase I

2004 ◽  
Vol 382 (3) ◽  
pp. 995-1001 ◽  
Author(s):  
Shaoxian ZHU ◽  
Andrew HANNEMAN ◽  
Vernon N. REINHOLD ◽  
Andrew M. SPENCE ◽  
Harry SCHACHTER
Keyword(s):  
Caenorhabditis Elegans ◽  
Chromosome Number ◽  
Null Mutant ◽  
Wild Type ◽  
Knock Out ◽  
C Elegans ◽  
In The Wild ◽  
Wild Type Worm ◽  
Type C ◽  
Nematode Worm

We have previously reported, from the nematode worm Caenor-habditis elegans, three genes (gly-12, gly-13 and gly-14) encoding enzymically active UDP-N-acetyl-D-glucosamine:α-3-D-mannoside β1,2-N-acetylglucosaminyltransferase I (GnT I), an enzyme essential for hybrid, paucimannose and complex N-glycan synthesis. We now describe a worm with null mutations in all three GnT I genes, gly-14 (III);gly-12 gly-13 (X) (III and X refer to the chromosome number). The triple-knock-out (TKO) worms have a normal phenotype, although they do not express GnT I activity and do not synthesize 31 paucimannose, complex and fucosylated oligomannose N-glycans present in the wild-type worm. The TKO worm has increased amounts of non-fucosylated oligomannose N-glycan structures, a finding consistent with the site of GnT I action. Five fucosylated oligomannose N-glycan structures were observed in TKO, but not wild-type, worms, indicating the presence of unusual GnT I-independent fucosyltransferases. It is concluded that wild-type C. elegans makes a large number of GnT I-dependent N-glycans that are not essential for normal worm development under laboratory conditions. The TKO worm may be more susceptible to mutations in other genes, thereby providing an approach for the identification of genes that interact with GnT I.

scholarly journals Caenorhabditis elegans pseudouridine synthase 1 activity in vivo: tRNA is a substrate, but not U2 small nuclear RNA1

2003 ◽  
Vol 372 (2) ◽  
pp. 595-602 ◽  
Author(s):  
Jeffrey R. PATTON ◽  
Richard W. PADGETT
Keyword(s):  
Caenorhabditis Elegans ◽  
Small Nuclear Rna ◽  
U2 Snrna ◽  
C Elegans ◽  
Pseudouridine Synthase ◽  
Gene Coding ◽  
Dual Specificity ◽  
Pseudouridine Synthases ◽  
In The Wild

The formation of pseudouridine (Ψ) from uridine is post-transcriptional and catalysed by pseudouridine synthases, several of which have been characterized from eukaryotes. Pseudouridine synthase 1 (Pus1p) has been well characterized from yeast and mice. In yeast, Pus1p has been shown to have dual substrate specificity, modifying uridines in tRNAs and at position 44 in U2 small nuclear RNA (U2 snRNA). In order to study the in vivo activity of a metazoan Pus1p, a knockout of the gene coding for the homologue of Pus1p in Caenorhabditis elegans was obtained. The deletion encompasses the first two putative exons and includes the essential aspartate that is required for activity in truA pseudouridine synthases. The locations of most modified nucleotides on small RNAs in C. elegans are not known, and the positions of Ψ were determined on four tRNAs and U2 snRNA. The uridine at position 27 of tRNAVal (AAC), a putative Pus1p-modification site, was converted into Ψ in the wild-type worms, but the tRNAVal (AAC) from mutant worms lacked the modification. Ψ formation at positions 13, 32, 38 and 39, all of which should be modified by other pseudouridine synthases, was not affected by the loss of Pus1p. The absence of Pus1p in C. elegans had no effect on the modification of U2 snRNA in vivo, even though worm U2 snRNA has a Ψ at position 45 (the equivalent of yeast U2 snRNA position 44) and at four other positions. This result was unexpected, given the known dual specificity of yeast Pus1p.

scholarly journals Multigenerational Regulation of the Caenorhabditis elegans Chromatin Landscape by Germline Small RNAs

2019 ◽  
Vol 53 (1) ◽  
pp. 289-311 ◽  
Author(s):  
Natasha E. Weiser ◽  
John K. Kim
Keyword(s):  
Gene Expression ◽  
Caenorhabditis Elegans ◽  
Small Rnas ◽  
Model Organism ◽  
Epigenetic Inheritance ◽  
Small Interfering Rnas ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Small Noncoding Rnas ◽  
Rna Pathways

In animals, small noncoding RNAs that are expressed in the germline and transmitted to progeny control gene expression to promote fertility. Germline-expressed small RNAs, including endogenous small interfering RNAs (endo-siRNAs) and Piwi-interacting RNAs (piRNAs), drive the repression of deleterious transcripts such as transposons, repetitive elements, and pseudogenes. Recent studies have highlighted an important role for small RNAs in transgenerational epigenetic inheritance via regulation of heritable chromatin marks; therefore, small RNAs are thought to convey an epigenetic memory of genomic self and nonself elements. Small RNA pathways are highly conserved in metazoans and have been best described for the model organism Caenorhabditis elegans. In this review, we describe the biogenesis, regulation, and function of C. elegans endo-siRNAs and piRNAs, along with recent insights into how these distinct pathways are integrated to collectively regulate germline gene expression, transgenerational epigenetic inheritance, and ultimately, animal fertility.

scholarly journals Non-genetic inheritance via the male germline in mammals

2019 ◽  
Vol 374 (1770) ◽  
pp. 20180118 ◽  
Author(s):  
Faye A. Baxter ◽  
Amanda J. Drake
Keyword(s):  
Early Life ◽  
First Generation ◽  
Epigenetic Inheritance ◽  
Later Life ◽  
Evolutionary Medicine ◽  
Maternal Line ◽  
Functional Changes ◽  
Male Germline ◽  
Male Line ◽  
Adverse Environmental Conditions

Numerous studies in humans and in animal models have demonstrated that exposure to adverse environmental conditions in early life results in long-term structural and functional changes in an organism, increasing the risk of cardiometabolic, neurobehavioural and reproductive disorders in later life. Such effects are not limited to the first generation offspring but may be transmitted to a second or a number of subsequent generations, through non-genomic mechanisms. While the transmission of ‘programmed’ effects through the maternal line could occur as a consequence of multiple influences, for example, altered maternal physiology, the inheritance of effects through the male line is more difficult to explain and there is much interest in a potential role for transgenerational epigenetic inheritance. In this review, we will discuss the mechanisms by which induced effects may be transmitted through the paternal lineage, with a particular focus on the role of epigenetic inheritance. This article is part of the theme issue ‘Developing differences: early-life effects and evolutionary medicine’.

scholarly journals Starvation Responses Throughout the Caenorhabditiselegans Life Cycle

Genetics ◽  
2020 ◽  
Vol 216 (4) ◽  
pp. 837-878
Author(s):  
L. Ryan Baugh ◽  
Patrick J. Hu
Keyword(s):  
Life Cycle ◽  
Epigenetic Inheritance ◽  
Egg Laying ◽  
Food Sources ◽  
Adult Health ◽  
Adaptive Responses ◽  
Comprehensive Overview ◽  
C Elegans ◽  
Maternal Provisioning ◽  
In The Wild

Caenorhabditis elegans survives on ephemeral food sources in the wild, and the species has a variety of adaptive responses to starvation. These features of its life history make the worm a powerful model for studying developmental, behavioral, and metabolic starvation responses. Starvation resistance is fundamental to life in the wild, and it is relevant to aging and common diseases such as cancer and diabetes. Worms respond to acute starvation at different times in the life cycle by arresting development and altering gene expression and metabolism. They also anticipate starvation during early larval development, engaging an alternative developmental program resulting in dauer diapause. By arresting development, these responses postpone growth and reproduction until feeding resumes. A common set of signaling pathways mediates systemic regulation of development in each context but with important distinctions. Several aspects of behavior, including feeding, foraging, taxis, egg laying, sleep, and associative learning, are also affected by starvation. A variety of conserved signaling, gene regulatory, and metabolic mechanisms support adaptation to starvation. Early life starvation can have persistent effects on adults and their descendants. With its short generation time, C. elegans is an ideal model for studying maternal provisioning, transgenerational epigenetic inheritance, and developmental origins of adult health and disease in humans. This review provides a comprehensive overview of starvation responses throughout the C. elegans life cycle.

Combinatorial control of touch receptor neuron expression in Caenorhabditis elegans

Development ◽  
1993 ◽  
Vol 119 (3) ◽  
pp. 773-783 ◽  
Author(s):  
S. Mitani ◽  
H. Du ◽  
D.H. Hall ◽  
M. Driscoll ◽  
M. Chalfie
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Types ◽  
Wild Type ◽  
Negative Regulators ◽  
C Elegans ◽  
Combinatorial Control ◽  
Touch Receptor Neurons ◽  
In The Wild ◽  
Receptor Neurons ◽  
Touch Receptor Neuron

Six touch receptor neurons with distinctive morphological features sense gentle touch in Caenorhabditis elegans. Previous studies have identified three genes (lin-32, unc-86 and mec-3) that regulate touch cell development. However, since other cell types also require these genes, we suspected that other genes help restrict the expression of touch cell characteristics to the six neurons seen in the wild type. To identify such genes, we have examined mutants defective in genes required for the development of other C. elegans cells for changes in the pattern of touch cell-specific features. Mutations in seven genes either reduce (lin-14) or increase (lin-4, egl-44, egl-46, sem-4, ced-3 and ced-4) the number of touch receptor-like cells. The combinatorial action of these genes, all of which are required for the production of many cell types, restrict the number of cells expressing touch receptor characteristics in wild-type animals by acting as positive and negative regulators and by removing cells by programmed cell death.

scholarly journals Caenorhabditis elegans as an indicator of toxicity of Bacillus thuringiensis strains to Meloidogyne incognita race 3

2018 ◽  
Vol 48 (7) ◽  
Author(s):  
Sandro Coelho Linhares Montalvão ◽  
Marcelo Tavares de Castro ◽  
Carlos Marcelo Silveira Soares ◽  
Luiz Eduardo Bassay Blum ◽  
Rose Gomes Monnerat
Keyword(s):  
Caenorhabditis Elegans ◽  
Meloidogyne Incognita ◽  
Root Knot Nematode ◽  
C Elegans ◽  
Antagonistic Microorganisms ◽  
Large Populations ◽  
Deep Plowing ◽  
Selection Of

ABSTRACT: The cotton plant (Gossypium hirsutum) is affected by several diseases of economic importance, among them root-knot nematode (Meloidogyne incognita races 3 and 4). Methods to control this disease include the application of nematicides, solarization, deep plowing, crop rotation and use of antagonistic microorganisms. Among species of Bacillus, there are strains that act as bioregulators and antagonists of several pathogens. Tests to identify these strains are hampered by the difficulty of obtaining large populations of the pathogen and by the time of execution of the in vivo tests that should be conducted for about 90 days. The objective of this research was to compare the toxicity of B. thuringiensis strains to two nematodes, M. incognita and Caenorhabditis elegans, evaluating the possibility of using C. elegans as an indicator for the selection of strains with biocontrol potential against M. incognita. Therefore, the toxicity of nine B. thuringiensis strains on C. elegans and M. incognita was evaluated under laboratory and greenhouse conditions. Most strains toxic to C. elegans in vitro were also toxic to M. incognita, and three of them (S906, S1192, S2036) significantly reduced the populations of the two nematodes. The toxic effect of B. thuringiensis strains on C. elegans was like that reported for the same bacterial isolates on M. incognita in vivo. These results suggested that it is plausible to use C. elegans as an indicator of toxicity for selection of B. thuringiensis strains toxic to M. incognita.

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