A species of nematode that is widely used in biological, biochemical, and genetic studies.
Proteins from the nematode species CAENORHABDITIS ELEGANS. The proteins from this species are the subject of scientific interest in the area of multicellular organism MORPHOGENESIS.
A genus of small free-living nematodes. Two species, CAENORHABDITIS ELEGANS and C. briggsae are much used in studies of genetics, development, aging, muscle chemistry, and neuroanatomy.
The functional hereditary units of HELMINTHS.
Proteins found in any species of helminth.
The external genitalia of the female. It includes the CLITORIS, the labia, the vestibule, and its glands.
Deoxyribonucleic acid that makes up the genetic material of helminths.
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
Ribonucleic acid in helminths having regulatory and catalytic roles as well as involvement in protein synthesis.
The genetic complement of a helminth (HELMINTHS) as represented in its DNA.
In gonochoristic organisms, congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. Effects from exposure to abnormal levels of GONADAL HORMONES in the maternal environment, or disruption of the function of those hormones by ENDOCRINE DISRUPTORS are included.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The normal length of time of an organism's life.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Carbamate derivative used as an insecticide, acaricide, and nematocide.
The gamete-producing glands, OVARY or TESTIS.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
A funnel-shaped fibromuscular tube that conducts food to the ESOPHAGUS, and air to the LARYNX and LUNGS. It is located posterior to the NASAL CAVITY; ORAL CAVITY; and LARYNX, and extends from the SKULL BASE to the inferior border of the CRICOID CARTILAGE anteriorly and to the inferior border of the C6 vertebra posteriorly. It is divided into the NASOPHARYNX; OROPHARYNX; and HYPOPHARYNX (laryngopharynx).
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
The process of laying or shedding fully developed eggs (OVA) from the female body. The term is usually used for certain INSECTS or FISHES with an organ called ovipositor where eggs are stored or deposited before expulsion from the body.
A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.
Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.
Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Any method used for determining the location of and relative distances between genes on a chromosome.
Substances used in the treatment or control of nematode infestations. They are used also in veterinary practice.
A family of transcription factors that contain two ZINC FINGER MOTIFS and bind to the DNA sequence (A/T)GATA(A/G).
Animals and plants which have, as their normal mode of reproduction, both male and female sex organs in the same individual.
A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
Periodic casting off FEATHERS; HAIR; or cuticle. Molting is a process of sloughing or desquamation, especially the shedding of an outer covering and the development of a new one. This phenomenon permits growth in ARTHROPODS, skin renewal in AMPHIBIANS and REPTILES, and the shedding of winter coats in BIRDS and MAMMALS.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
The mechanisms by which the SEX of an individual's GONADS are fixed.
An antihelminthic drug that has been tried experimentally in rheumatic disorders where it apparently restores the immune response by increasing macrophage chemotaxis and T-lymphocyte function. Paradoxically, this immune enhancement appears to be beneficial in rheumatoid arthritis where dermatitis, leukopenia, and thrombocytopenia, and nausea and vomiting have been reported as side effects. (From Smith and Reynard, Textbook of Pharmacology, 1991, p435-6)
The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.
The relationships of groups of organisms as reflected by their genetic makeup.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
The muscles of the PHARYNX are voluntary muscles arranged in two layers. The external circular layer consists of three constrictors (superior, middle, and inferior). The internal longitudinal layer consists of the palatopharyngeus, the salpingopharyngeus, and the stylopharyngeus. During swallowing, the outer layer constricts the pharyngeal wall and the inner layer elevates pharynx and LARYNX.
The entire nerve apparatus, composed of a central part, the brain and spinal cord, and a peripheral part, the cranial and spinal nerves, autonomic ganglia, and plexuses. (Stedman, 26th ed)
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
Mutation process that restores the wild-type PHENOTYPE in an organism possessing a mutationally altered GENOTYPE. The second "suppressor" mutation may be on a different gene, on the same gene but located at a distance from the site of the primary mutation, or in extrachromosomal genes (EXTRACHROMOSOMAL INHERITANCE).
Genes that are introduced into an organism using GENE TRANSFER TECHNIQUES.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.
Loose connective tissue lying under the DERMIS, which binds SKIN loosely to subjacent tissues. It may contain a pad of ADIPOCYTES, which vary in number according to the area of the body and vary in size according to the nutritional state.
Validation of the SEX of an individual by inspection of the GONADS and/or by genetic tests.
Contractile tissue that produces movement in animals.
The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.
The processes occurring in early development that direct morphogenesis. They specify the body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative positions. Included are axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning, etc.
The joining of RNA from two different genes. One type of trans-splicing is the "spliced leader" type (primarily found in protozoans such as trypanosomes and in lower invertebrates such as nematodes) which results in the addition of a capped, noncoding, spliced leader sequence to the 5' end of mRNAs. Another type of trans-splicing is the "discontinuous group II introns" type (found in plant/algal chloroplasts and plant mitochondria) which results in the joining of two independently transcribed coding sequences. Both are mechanistically similar to conventional nuclear pre-mRNA cis-splicing. Mammalian cells are also capable of trans-splicing.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
RNA consisting of two strands as opposed to the more prevalent single-stranded RNA. Most of the double-stranded segments are formed from transcription of DNA by intramolecular base-pairing of inverted complementary sequences separated by a single-stranded loop. Some double-stranded segments of RNA are normal in all organisms.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.
The observable response an animal makes to any situation.
Genes whose expression is easily detectable and therefore used to study promoter activity at many positions in a target genome. In recombinant DNA technology, these genes may be attached to a promoter region of interest.
One of two types of muscle in the body, characterized by the array of bands observed under microscope. Striated muscles can be divided into two subtypes: the CARDIAC MUSCLE and the SKELETAL MUSCLE.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Transport proteins that carry specific substances in the blood or across cell membranes.
A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.
A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)
The sensation of cold, heat, coolness, and warmth as detected by THERMORECEPTORS.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
A genus of parasitic nematode worms which infest the duodenum and stomach of domestic and wild herbivores, which ingest it with the grasses (POACEAE) they eat. Infestation of man is accidental.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
A family of conserved cell surface receptors that contain EPIDERMAL GROWTH FACTOR repeats in their extracellular domain and ANKYRIN repeats in their cytoplasmic domains. The cytoplasmic domain of notch receptors is released upon ligand binding and translocates to the CELL NUCLEUS where it acts as transcription factor.
A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.
The total process by which organisms produce offspring. (Stedman, 25th ed)
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Specialized afferent neurons capable of transducing sensory stimuli into NERVE IMPULSES to be transmitted to the CENTRAL NERVOUS SYSTEM. Sometimes sensory receptors for external stimuli are called exteroceptors; for internal stimuli are called interoceptors and proprioceptors.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.
Undifferentiated cells resulting from cleavage of a fertilized egg (ZYGOTE). Inside the intact ZONA PELLUCIDA, each cleavage yields two blastomeres of about half size of the parent cell. Up to the 8-cell stage, all of the blastomeres are totipotent. The 16-cell MORULA contains outer cells and inner cells.
An antineoplastic agent with alkylating properties. It also acts as a mutagen by damaging DNA and is used experimentally for that effect.
The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.
The capacity to conceive or to induce conception. It may refer to either the male or female.
Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.
Screening techniques first developed in yeast to identify genes encoding interacting proteins. Variations are used to evaluate interplay between proteins and other molecules. Two-hybrid techniques refer to analysis for protein-protein interactions, one-hybrid for DNA-protein interactions, three-hybrid interactions for RNA-protein interactions or ligand-based interactions. Reverse n-hybrid techniques refer to analysis for mutations or other small molecules that dissociate known interactions.
Neurons which activate MUSCLE CELLS.
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
Morphological and physiological development of EMBRYOS.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.
Genes that have a suppressor allele or suppressor mutation (SUPPRESSION, GENETIC) which cancels the effect of a previous mutation, enabling the wild-type phenotype to be maintained or partially restored. For example, amber suppressors cancel the effect of an AMBER NONSENSE MUTATION.
Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).
Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.
Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.
Populations of thin, motile processes found covering the surface of ciliates (CILIOPHORA) or the free surface of the cells making up ciliated EPITHELIUM. Each cilium arises from a basic granule in the superficial layer of CYTOPLASM. The movement of cilia propels ciliates through the liquid in which they live. The movement of cilia on a ciliated epithelium serves to propel a surface layer of mucus or fluid. (King & Stansfield, A Dictionary of Genetics, 4th ed)
The alignment of CHROMOSOMES at homologous sequences.
Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.
A class of animal lectins that bind specifically to beta-galactoside in a calcium-independent manner. Members of this class are distiguished from other lectins by the presence of a conserved carbohydrate recognition domain. The majority of proteins in this class bind to sugar molecules in a sulfhydryl-dependent manner and are often referred to as S-type lectins, however this property is not required for membership in this class.
A cell surface receptor for INSULIN. It comprises a tetramer of two alpha and two beta subunits which are derived from cleavage of a single precursor protein. The receptor contains an intrinsic TYROSINE KINASE domain that is located within the beta subunit. Activation of the receptor by INSULIN results in numerous metabolic changes including increased uptake of GLUCOSE into the liver, muscle, and ADIPOSE TISSUE.
A species of parasitic nematode usually found in domestic pigs and a few other animals. Human infection can also occur, presumably as result of handling pig manure, and can lead to intestinal obstruction.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
The occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from a single ZYGOTE, as opposed to CHIMERISM in which the different cell populations are derived from more than one zygote.
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.
The parts of the gene sequence that carry out the different functions of the GENES.
The fertilized OVUM resulting from the fusion of a male and a female gamete.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.
Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.
A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.
A superfamily of nematodes of the order RHABDITIDA. Characteristics include an open tube stoma and an excretory system with lateral canals.

Regulation of body length and male tail ray pattern formation of Caenorhabditis elegans by a member of TGF-beta family. (1/9183)

We have identified a new member of the TGF-beta superfamily, CET-1, from Caenorhabditis elegans, which is expressed in the ventral nerve cord and other neurons. cet-1 null mutants have shortened bodies and male tail abnormal phenotype resembling sma mutants, suggesting cet-1, sma-2, sma-3 and sma-4 share a common pathway. Overexpression experiments demonstrated that cet-1 function requires wild-type sma genes. Interestingly, CET-1 appears to affect body length in a dose-dependent manner. Heterozygotes for cet-1 displayed body lengths ranging between null mutant and wild type, and overexpression of CET-1 in wild-type worms elongated body length close to lon mutants. In male sensory ray patterning, lack of cet-1 function results in ray fusions. Epistasis analysis revealed that mab-21 lies downstream and is negatively regulated by the cet-1/sma pathway in the male tail. Our results show that cet-1 controls diverse biological processes during C. elegans development probably through different target genes.  (+info)

Alzheimer's disease: clues from flies and worms. (2/9183)

Presenilin mutations give rise to familial Alzheimer's disease and result in elevated production of amyloid beta peptide. Recent evidence that presenilins act in developmental signalling pathways may be the key to understanding how senile plaques, neurofibrillary tangles and apoptosis are all biochemically linked.  (+info)

Alterations in the conserved SL1 trans-spliced leader of Caenorhabditis elegans demonstrate flexibility in length and sequence requirements in vivo. (3/9183)

Approximately 70% of mRNAs in Caenorhabditis elegans are trans spliced to conserved 21- to 23-nucleotide leader RNAs. While the function of SL1, the major C. elegans trans-spliced leader, is unknown, SL1 RNA, which contains this leader, is essential for embryogenesis. Efforts to characterize in vivo requirements of the SL1 leader sequence have been severely constrained by the essential role of the corresponding DNA sequences in SL1 RNA transcription. We devised a heterologous expression system that circumvents this problem, making it possible to probe the length and sequence requirements of the SL1 leader without interfering with its transcription. We report that expression of SL1 from a U2 snRNA promoter rescues mutants lacking the SL1-encoding genes and that the essential embryonic function of SL1 is retained when approximately one-third of the leader sequence and/or the length of the leader is significantly altered. In contrast, although all mutant SL1 RNAs were well expressed, more severe alterations eliminate this essential embryonic function. The one non-rescuing mutant leader tested was never detected on messages, demonstrating that part of the leader sequence is essential for trans splicing in vivo. Thus, in spite of the high degree of SL1 sequence conservation, its length, primary sequence, and composition are not critical parameters of its essential embryonic function. However, particular nucleotides in the leader are essential for the in vivo function of the SL1 RNA, perhaps for its assembly into a functional snRNP or for the trans-splicing reaction.  (+info)

The Caenorhabditis elegans sex determination gene mog-1 encodes a member of the DEAH-Box protein family. (4/9183)

In the Caenorhabditis elegans hermaphrodite germ line, the sex-determining gene fem-3 is repressed posttranscriptionally to arrest spermatogenesis and permit oogenesis. This repression requires a cis-acting regulatory element in the fem-3 3' untranslated region; the FBF protein, which binds to this element; and at least six mog genes. In this paper, we report the molecular characterization of mog-1 as well as additional phenotypic characterization of this gene. The mog-1 gene encodes a member of the DEAH-box family. Three mog-1 alleles possess premature stop codons and are likely to be null alleles, and one is a missense mutation and is likely to retain residual activity. mog-1 mRNA is expressed in both germ line and somatic tissues and appears to be ubiquitous. The MOG-1 DEAH-box protein is most closely related to proteins essential for splicing in the yeast Saccharomyces cerevisiae, but splicing appears to occur normally in a mog-1-null mutant. In addition to its involvement in the sperm-oocyte switch and control of fem-3, zygotic mog-1 is required for robust germ line proliferation and for normal growth during development. We suggest that mog-1 plays a broader role in RNA regulation than previously considered.  (+info)

NMD3 encodes an essential cytoplasmic protein required for stable 60S ribosomal subunits in Saccharomyces cerevisiae. (5/9183)

A mutation in NMD3 was found to be lethal in the absence of XRN1, which encodes the major cytoplasmic exoribonuclease responsible for mRNA turnover. Molecular genetic analysis of NMD3 revealed that it is an essential gene required for stable 60S ribosomal subunits. Cells bearing a temperature-sensitive allele of NMD3 had decreased levels of 60S subunits at the nonpermissive temperature which resulted in the formation of half-mer polysomes. Pulse-chase analysis of rRNA biogenesis indicated that 25S rRNA was made and processed with kinetics similar to wild-type kinetics. However, the mature RNA was rapidly degraded, with a half-life of 4 min. Nmd3p fractionated as a cytoplasmic protein and sedimented in the position of free 60S subunits in sucrose gradients. These results suggest that Nmd3p is a cytoplasmic factor required for a late cytoplasmic assembly step of the 60S subunit but is not a ribosomal protein. Putative orthologs of Nmd3p exist in Drosophila, in nematodes, and in archaebacteria but not in eubacteria. The Nmd3 protein sequence does not contain readily recognizable motifs of known function. However, these proteins all have an amino-terminal domain containing four repeats of Cx2C, reminiscent of zinc-binding proteins, implicated in nucleic acid binding or protein oligomerization.  (+info)

The nuclear receptor superfamily has undergone extensive proliferation and diversification in nematodes. (6/9183)

The nuclear receptor (NR) superfamily is the most abundant class of transcriptional regulators encoded in the Caenorhabditis elegans genome, with >200 predicted genes revealed by the screens and analysis of genomic sequence reported here. This is the largest number of NR genes yet described from a single species, although our analysis of available genomic sequence from the related nematode Caenorhabditis briggsae indicates that it also has a large number. Existing data demonstrate expression for 25% of the C. elegans NR sequences. Sequence conservation and statistical arguments suggest that the majority represent functional genes. An analysis of these genes based on the DNA-binding domain motif revealed that several NR classes conserved in both vertebrates and insects are also represented among the nematode genes, consistent with the existence of ancient NR classes shared among most, and perhaps all, metazoans. Most of the nematode NR sequences, however, are distinct from those currently known in other phyla, and reveal a previously unobserved diversity within the NR superfamily. In C. elegans, extensive proliferation and diversification of NR sequences have occurred on chromosome V, accounting for > 50% of the predicted NR genes.  (+info)

Characterization of a mutant pancreatic eIF-2alpha kinase, PEK, and co-localization with somatostatin in islet delta cells. (7/9183)

Phosphorylation of eukaryotic translation initiation factor-2alpha (eIF-2alpha) is one of the key steps where protein synthesis is regulated in response to changes in environmental conditions. The phosphorylation is carried out in part by three distinct eIF-2alpha kinases including mammalian double-stranded RNA-dependent eIF-2alpha kinase (PKR) and heme-regulated inhibitor kinase (HRI), and yeast GCN2. We report the identification and characterization of a related kinase, PEK, which shares common features with other eIF-2alpha kinases including phosphorylation of eIF-2alpha in vitro. We show that human PEK is regulated by different mechanisms than PKR or HRI. In contrast to PKR or HRI, which are dependent on autophosphorylation for their kinase activity, a point mutation that replaced the conserved Lys-614 with an alanine completely abolished the eIF-2alpha kinase activity, whereas the mutant PEK was still autophosphorylated when expressed in Sf-9 cells. Northern blot analysis indicates that PEK mRNA was predominantly expressed in pancreas, though low expression was also present in several tissues. Consistent with the high levels of mRNA in pancreas, the PEK protein was only detected in human pancreatic islets, and the kinase co-localized with somatostatin, a pancreatic delta cell-specific hormone. Thus PEK is believed to play an important role in regulating protein synthesis in the pancreatic islet, especially in islet delta cells.  (+info)

Characterization of a Caenorhabditis elegans recA-like gene Ce-rdh-1 involved in meiotic recombination. (8/9183)

A recA-like gene was identified in the Caenorhabditis elegans genome project database. The putative product of the gene, termed Ce-rdh-1 (C. elegans RAD51 and DMC1/LIM15 homolog 1), consists of 357 amino acid residues. The predicted amino acid sequence of Ce-rdh-1 showed 46-60% identity to both RAD51 type and DMC1/LIM15 type genes in several eukaryote species. The results of RNAi (RNA-mediated interference) indicated that repression of Ce-rdh-1 blocked chromosome condensation of six bivalents and dissociation of chiasmata in oocytes of F1 progeny. Oogenesis did not proceed to the diakinesis stage. Accordingly, all the eggs produced (F2) died in early stages. These results suggest that Ce-rdh-1 participates in meiotic recombination.  (+info)

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WormBase is an online biological database about the biology and genome of the nematode model organism Caenorhabditis elegans and contains information about other related nematodes. WormBase is used by the C. elegans research community both as an information resource and as a place to publish and distribute their results. The database is regularly updated with new versions being released every two months. WormBase is one of the organizations participating in the Generic Model Organism Database (GMOD) project. WormBase comprises the following main data sets: The annotated genomes of Caenorhabditis elegans, Caenorhabditis briggsae, Caenorhabditis remanei, Caenorhabditis brenneri, Caenorhabditis angaria, Pristionchus pacificus, Haemonchus contortus, Meloidogyne hapla, Meloidogyne incognita, Brugia malayi and Onchocerca volvulus; Hand-curated annotations describing the function of ~20,500 C. elegans protein-coding genes and ~16,000 C. elegans non-coding genes; Gene families; Orthologies; Genomic ...
The molecular mechanisms underlying muscle atrophy during spaceflight are not well understood. We have analyzed the effects of a 10-day spaceflight on Caenorhabditis elegans muscle development. DNA microarray, real-time quantitative PCR, and quantitative western blot analyses revealed that the amount of MHC in both body-wall and pharyngeal muscle decrease in response to spaceflight. Decreased transcription of the body-wall myogenic transcription factor HLH-1 (CeMyoD) and of the three pharyngeal myogenic transcription factors, PEB-1, CEH-22 and PHA-4 were also observed. Upon return to Earth animals displayed reduced rates of movement, indicating a functional defect. These results demonstrate that C. elegans muscle development is altered in response to spaceflight. This altered development occurs at the level of gene transcription and was observed in the presence of innervation, not simply in isolated cells. This important finding coupled with past observations of decreased levels of the same ...
The nematode worm Caenorhabditis elegans is a model system for the study of the genetic basis of aging. Maternal-effect mutations in four genes-clk-1, clk-2, clk-3, and gro-1- interact genetically to determine both the duration of development and life-span. Analysis of the phenotypes of these mutants suggests the existence of a general physiological clock in the worm. Mutations in certain genes involved in dauer formation (an alternative larval stage induced by adverse conditions in which development is arrested) can also extend life-span, but the life extension of Clock mutants appears to be independent of these genes. The daf-2(e1370) clk-1(e2519) worms, which carry life-span-extending mutations from two different pathways, live nearly five times as long as wild-type worms.. ...
The germ cells of multicellular organisms protect their developmental potential through specialized mechanisms. A shared feature of germ cells from worms to humans is the presence of nonmembrane-bound, ribonucleoprotein organelles called germ granules. Depletion of germ granules in Caenorhabditis elegans (i.e., P granules) leads to sterility and, in some germlines, expression of the neuronal transgene unc-119::gfp and the muscle myosin MYO-3. Thus, P granules are hypothesized to maintain germ cell totipotency by preventing somatic development, although the mechanism by which P granules carry out this function is unknown. In this study, we performed transcriptome and single molecule RNA-FISH analyses of dissected P granule-depleted gonads at different developmental stages. Our results demonstrate that P granules are necessary for adult germ cells to downregulate spermatogenesis RNAs and to prevent the accumulation of numerous soma-specific RNAs. P granule-depleted gonads that express the ...
TY - JOUR. T1 - The Caenorhabditis elegans AMP-activated protein kinase AAK-2 is phosphorylated by LKB1 and is required for resistance to oxidative stress and for normal motility and foraging behavior. AU - Lee, Hyojin. AU - Jeong, Soo Cho. AU - Lambacher, Nils. AU - Lee, Jieun. AU - Lee, Se Jin. AU - Tae, Hoon Lee. AU - Gartner, Anton. AU - Koo, Hyeon Sook. PY - 2008/5/30. Y1 - 2008/5/30. N2 - AAK-2 is one of two α isoforms of the AMP-activated protein kinase in Caenorhabditis elegans and is involved in life span maintenance, stress responses, and germ cell cycle arrest upon dauer entry. We found that AAK-2 was phosphorylated at threonine 243 in response to paraquat treatment and that this phosphorylation depends on PAR-4, the C. elegans LKB1 homologue. Both aak-2 mutation and par-4 knockdown increased the sensitivity of C. elegans worms to paraquat, and the double deficiency did not further increase sensitivity, indicating that aak-2 and par-4 act in a linear pathway. Both mutations also ...
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Defining a behavior that requires the function of specific neurons in the free-living nematode Caenorhabditis elegans can allow one to screen for mutations that disrupt the specification or function of those neurons. We identified serotonin-immunoreactive neurons required for tail curling or turnin …
Mouse mAb M38 was used in indirect immunofluorescence experiments to detect a stage-specific antigen on the surface of the first larval stage (L1) of the free-living nematode Caenorhabditis elegans, and to detect alterations in the apparent expression of this antigen in two distinct classes of C. elegans mutants. In previously described srf-2 and srf-3 mutants (Politz S. M., M. T. Philipp, M. Estevez, P.J. OBrien, and K. J. Chin. 1990. Proc. Natl. Acad. Sci. USA. 87:2901-2905), the antigen is not detected on the surface of any stage. Conversely, in srf-(yj43) and other similar mutants, the antigen is expressed on the surface of the first through the fourth (L4) larval stages. To understand the molecular basis of these alterations, the antigen was characterized in gel immunoblotting experiments. After SDS-PAGE separation and transfer to nitrocellulose, M38 detected a protein antigen in extracts of wild-type L1 populations. The antigen was sensitive to digestion by Pronase and O-glycanase ...
The detection and abundance of Escherichia coli in water is used to monitor and mandate the quality of drinking and recreational water. Distinguishing commensal waterborne E. coli isolates from those that cause diarrhea or extraintestinal disease in humans is important for quantifying human health risk. A DNA microarray was used to evaluate the distribution of virulence genes in 148 E. coli environmental isolates from a watershed in eastern Ontario, Canada, and in eight clinical isolates. Their pathogenic potential was evaluated with Caenorhabditis elegans, and the concordance between the bioassay result and the pathotype deduced by genotyping was explored. Isolates identified as potentially pathogenic on the basis of their complement of virulence genes were significantly more likely to be pathogenic to C. elegans than those determined to be potentially nonpathogenic. A number of isolates that were identified as nonpathogenic on the basis of genotyping were pathogenic in the infection assay, ...
P-glycoproteins can cause multidrug resistance in mammalian tumor cells by active extrusion of cytotoxic drugs. The natural function of these evolutionarily conserved, membrane-bound ATP binding transport proteins is unknown. In mammals, P-glycoproteins are abundantly present in organs associated with the digestive tract. We have studied the tissue-specific expression of Caenorhabditis elegans P-glycoprotein genes pgp-1 and pgp-3 by transformation of nematodes with pgp-lacZ gene fusion constructs in which the promoter area of the pgp genes was fused to the coding region of lacZ. Expression of pgp-1 and pgp-3, as inferred from pgp-lacZ transgenic nematodes, was confined to the intestinal cells. The expression patterns of both genes were virtually indistinguishable. Quantitative analysis of pgp mRNA levels during development showed that pgp-1, -2, and -3 were expressed throughout the life cycle of C.elegans, albeit with some variation indicating developmental regulation. The expression of P-glycoprotein
Development of the nematode Caenorhabditis elegans is highly reproducible and the fate of every somatic cell has been reported. We describe here a previously uncharacterized cell fate in C. elegans: we show that germ cells, which in hermaphrodites can differentiate into sperm and oocytes, also undergo apoptotic cell death. In adult hermaphrodites, over 300 germ cells die, using the same apoptotic execution machinery (ced-3, ced-4 and ced-9) as the previously described 131 somatic cell deaths. However, this machinery is activated by a distinct pathway, as loss of egl-1 function, which inhibits somatic cell death, does not affect germ cell apoptosis. Germ cell death requires ras/MAPK pathway activation and is used to maintain germline homeostasis. We suggest that apoptosis eliminates excess germ cells that acted as nurse cells to provide cytoplasmic components to maturing oocytes.. ...
Mutations in the clk-1 gene of the nematode Caenorhabditis elegans result in an average slowing of a variety of developmental and physiological processes, including the cell cycle, embryogenesis, post-embryonic growth, rhythmic behaviors and aging. In yeast, a CLK-1 homologue is absolutely required …
Aging is characterized by general physiological decline over time. A hallmark of human senescence is the onset of various age-related afflictions including neurodegeneration, cardiovascular disease and cancer. Although environmental and stochastic factors undoubtedly contribute to the increased incidence of disease with age, recent studies suggest that intrinsic genetic determinants govern both life span and overall health. Current aging research aims at achieving the longevity dividend, in which life span extension in humans is accomplished with a concomitant increase in the quality of life (Olshansky et al., 2007). Significant progress has been made using model organisms, especially the nematode worm Caenorhabditis elegans, to delineate the genetic and biochemical pathways involved in aging to identify strategies for therapeutic intervention in humans. In this review, we discuss how C. elegans has contributed to our understanding of insulin signaling and aging. ...
rdf:RDF xmlns:dcterms=http://purl.org/dc/terms/ xmlns:dc=http://purl.org/dc/elements/1.1/ xmlns:rdf=http://www.w3.org/1999/02/22-rdf-syntax-ns# xmlns:bibo=http://purl.org/ontology/bibo/ xmlns:dspace=http://digital-repositories.org/ontologies/dspace/0.1.0# xmlns:foaf=http://xmlns.com/foaf/0.1/ xmlns:void=http://rdfs.org/ns/void# xmlns:xsd=http://www.w3.org/2001/XMLSchema# , ,rdf:Description rdf:about=https://kops.uni-konstanz.de/rdf/resource/123456789/34900, ,bibo:uri rdf:resource=https://kops.uni-konstanz.de/handle/123456789/34900/, ,dc:creator,Deehan, Kevin,/dc:creator, ,dc:creator,Wilson, Kristy J.,/dc:creator, ,dc:language,eng,/dc:language, ,dcterms:abstract xml:lang=eng,UNC-89 is a giant polypeptide located at the sarcomeric M-line of Caenorhabditis elegans muscle. The human homologue is obscurin. To understand how UNC-89 is localized and functions, we have been identifying its binding partners. Screening a yeast two-hybrid library revealed that UNC-89 interacts with ...
Ninety-five mutants of the nematode Caenorhabditis elegans altered in the cell lineages of the vulva have been isolated on the basis of their displaying one of two phenotypes, Vulvaless or Multivulva. In Vulvaless mutants, which define 12 genes, no vulva is present. In Multivulva mutants, which define ten genes, one or more supernumerary vulva-like protrusions are located along the ventral side of the animal. A single recessive mutation is responsible for the phenotypes of most, but not all, of these strains. Fifteen of these 22 genes are represented by multiple alleles. We have shown by a variety of genetic criteria that mutations that result in a Vulvaless or Multivulva phenotype in six of the 22 genes most likely eliminate gene function. In addition, Vulvaless or Multivulva mutations in seven of the other genes most likely result in a partial reduction of gene function; the absence of the activity of any of these genes probably results in lethality or sterility. Our results suggest that we ...
As a consequence of the Earths axial rotation, organisms display daily recurring rhythms in behavior and biochemical properties, such as hormone titers. The neuronal system controlling such changes is best studied in the fruit fly Drosophila melanogaster. In the nematode worm Caenorhabditis elegans, most homologs of these genes function in the heterochronic pathway controlling the (timing of) developmental events. Recent data indicate that in the worm at least one of the genes involved in developmental timing is also active in circadian rhythm control, thereby opening up new perspectives on a central (neuronal) timer interfering with many processes. Also, new neuropeptidergic clock homologs have been identified in nematodes, supporting the idea of a broad range of clock-regulated targets. We will describe the current knowledge on homologous clock genes in C. elegans with a focus on the recently discovered pigment dispersing factor gene homologs. Similarities between developmental and daily ...
The pace of technical developments allowing the direct manipulation of genome sequences has seen a marked acceleration in recent years with the emergence of RNA-targeted nucleases derived from bacterial immune systems (Doudna and Charpentier 2014; Zetsche et al. 2015). In particular, the binary system relying on the Streptococcus pyogenes Cas9 endonuclease targeted by CRISPR (clustered, regularly interspaced, short, palindromic repeat) RNAs has been successfully used to generate point mutations, deletion, or DNA insertions in an ever-growing number of experimental systems. S. pyogenes CRISPR/Cas9 has been adapted early on in the model nematode Caenorhabditis elegans (Friedland et al. 2013; Dickinson et al. 2013; Chen et al. 2013; Frøkjær-Jensen 2013; Dickinson and Goldstein 2016). Previously, heritable genome engineering could only be achieved in C. elegans by remobilizing a Drosophila Mos1 transposon, which could be inserted and excised in the germline (Robert and Bessereau 2007; ...
The vaccinia-related kinases (VRKs) are highly conserved throughout the animal kingdom and phosphorylate several chromatin proteins and transcription factors. In early Caenorhabditis elegans embryos, VRK-1 is required for proper nuclear envelope formation. In this work, we present the first investigation of the developmental role of VRKs by means of a novel C. elegans vrk-1 mutant allele. We found that VRK-1 is essential in hermaphrodites for formation of the vulva, uterus, and utse and for development and maintenance of the somatic gonad and thus the germ line. VRK-1 regulates anchor cell polarity and the timing of anchor cell invasion through the basement membranes separating vulval and somatic gonadal cells during the L3 larval stage. VRK-1 is also required for proper specification and proliferation of uterine cells and sex myoblasts. Expression of the fibroblast growth factor-like protein EGL-17 and its receptor EGL-15 is reduced in vrk-1 mutants, suggesting that VRK-1 might act at least ...
Mutations in the gene unc-53 of Caenorhabditis elegans result in behavioral and anatomical abnormalities. Immunocytochemistry and electron microscopy revealed neuroanatomical defects in all main longitudinal nervous tracts. Whole tracts were found to
Large-conductance calcium and voltage-activated potassium channels, termed SLO-1 (or BK), are pivotal players in the regulation of cell excitability across the animal phyla. Furthermore, emerging evidence indicates that these channels are key mediators of a number of neuroactive drugs, including the most recent new anthelmintic, the cyclo-octadepsipeptide emodepside. Detailed reviews of the structure, function and pharmacology of BK channels have recently been provided (Salkoff et al. in Nat Rev Neurosci 7:921-931, 2006; Ghatta et al. in Pharmacol Ther 110:103-116, 2006) and therefore these aspects will only briefly be covered here. The purpose of this review is to discuss how SLO-1 channels might function as regulators of neural transmission and network activity. In particular, we focus on the role of SLO-1 in the regulation of Caenorhabditis elegans behaviour and highlight the role of this channel as an effector for pleiotropic actions of neuroactive drugs, including emodepside. On the premise ...
Microsporidia comprise a phylum of obligate intracellular pathogens related to fungi that infect virtually all animals. Recently, the nematode Caenorhabditis elegans has been developed as a convenient model for studying microsporidia infection in a whole-animal host through the identification and characterization of a natural microsporidian pathogen of this commonly studied laboratory organism. The C. elegans natural microsporidian pathogen is named Nematocida parisii, and it causes a lethal intestinal infection in C. elegans. Comparison of the genomes of N. parisii and its closely related species Nematocida sp. 1, together with the genomes of other microsporidian species, has provided insight into the evolutionary events that led to the emergence of the large, specialized microsporidia phylum. Cell biology studies of N. parisii infection in C. elegans have shown how N. parisii restructures host intestinal cells and, in particular, how it hijacks host exocytosis for nonlytic exit to facilitate
Abstract The insulin/insulin-like growth factor-like signaling (IIS) pathway in metazoans has evolutionarily conserved roles in growth control, metabolic homeostasis, stress responses, reproduction, and lifespan. Genetic manipulations that reduce IIS in the nematode worm Caenorhabditis elegans, the fruit fly Drosophila melanogaster, and the mouse have been shown not only to produce substantial increases in lifespan but also to ameliorate several age-related diseases. In C. elegans, the multitude of phenotypes produced by the reduction in IIS are all suppressed in the absence of the worm FOXO transcription factor, DAF-16, suggesting that they are all under common regulation. It is not yet clear in other animal models whether the activity of FOXOs mediate all of the physiological effects of reduced IIS, especially increased lifespan. We have addressed this issue by examining the effects of reduced IIS in the absence of dFOXO in Drosophila, using a newly generated null allele of dfoxo. We found ...
Extensive studies have been carried out on Caenorhabditis elegans as a model organism to elucidate mechanisms of aging and the effects of perturbing known aging-related genes on lifespan and behavior. This research has generated large amounts of experimental data that is increasingly difficult to integrate and analyze with existing databases and domain knowledge. To address this challenge, we demonstrate a scalable and effective approach for automatic evidence gathering and evaluation that leverages existing experimental data and literature-curated facts to identify genes involved in aging and lifespan regulation in C. elegans. We developed a semantic knowledge base for aging by integrating data about C. elegans genes from WormBase with data about 2005 human and model organism genes from GenAge and 149 genes from GenDR, and with the Bio2RDF network of linked data for the life sciences. Using HyQue (a Semantic Web tool for hypothesis-based querying and evaluation) to interrogate this knowledge base, we
RNA interference (RNAi) is a widespread and widely exploited phenomenon which has potential as a strategy for both the treatment of disease and pest control. RNAi results in down‐regulation of a specific gene in response to the production of small interfering RNAs (siRNAs). RNAi is one of a family of processes mediated by small non‐coding RNAs [1], [2]. In Caenorhabditis elegans, and in a number of other organisms, RNAi is systemic so that the introduction of dsRNA into one tissue triggers gene silencing in other tissues [3], [4], [5], [6], [7]. Furthermore, systemic RNAi enables C. elegans and other organisms to exhibit environmental RNAi [5]. For example, feeding C. elegans on bacteria expressing dsRNA initiates a widespread RNAi response [8], [9]. Studies in C. elegans and other organisms have provided mechanistic insights into RNAi [4], [10], [11], [12], [13], although the role of exogenous RNAi in the normal life of C. elegans and other animals remains unclear [14].. Whilst C. elegans ...
During the course of normal embryonic and post-embryonic development, 131 cells in a Caenorhabditis elegans hermaphrodite undergo programmed cell death. Loss of function mutations in either of the genes ced-3 or ced-4 abolish cell deaths, enabling these undead cells to survive and be incorporated into the adult with no obvious deleterious consequences. Ultrastructural reconstructions have shown that undead cells exhibit many differentiated characteristics. Most of the reconstructed cells appeared to be neurons with all the characteristic features associated with such cells, such as processes, synaptic vesicles and presynaptic specializations. However, clear morphological differences were seen among the undead neurons, suggesting a diversity of cell type. One of the reconstructed cells was a rectal epithelial cell, which had displaced its lineal sister that normally functions in this role. Removal of the ability to undergo programmed cell death by mutation therefore reveals a diversity of ...
We are studying the development of the intestine in the small free-living nematode worm Caenorhabditis elegans. The worm intestine develops as a simple clone of cells, entirely deriving from a single cell in the eight-cell embryo. We mainly focus on the transcription factor network that drives development of the intestine. From our work and that of others, we now know all the core transcription factors that control intestinal genes, from specification to differentiation, and they all are GATA factors similar to the factors that are central to the development of the human intestine. We are now trying to figure out how these factors actually work, i.e. to define the molecular and thermodynamic basis of developmental specificity. Does all the specificity reside in the DNA binding domain? And if so, how much does the binding free energy to an intestinal gene differ from the binding free energy to a gene expressed in a different lineage, e.g. the hypodermis (skin)? Are there other protein domains ...
During gastrulation of the nematode worm Caenorhabditis elegans, individual cells ingress into a solid ball of cells. Gastrulation in a basal nematode, in contrast, has now been found to occur by invagination into a blastocoel, revealing an unanticipated embryological affinity between nematodes and all other triploblastic metazoans. ...
LAG1 is a longevity gene, the first such gene to be identified and cloned from the yeast Saccharomyces cerevisiae. A close homolog of this gene, which we call LAC1, has been found in the yeast genome. We have cloned the human homolog of LAG1 with the ultimate goal of examining its possible function in human aging. In the process, we have also cloned a homolog from the nematode worm Caenorhabditis elegans. Both of these homologs, LAG1Hs and LAG1Ce-1, functionally complemented the lethality of a lag1delta lac1delta double deletion, despite low overall sequence similarity to the yeast proteins. The proteins shared a short sequence, the Lag1 motif, and a similar transmembrane domain profile. Another, more distant human homolog, TRAM, which lacks this motif, did not complement. LAG1Hs also restored the life span of the double deletion, demonstrating that it functions in establishing the longevity phenotype in yeast. LAG1Hs mapped to 19p12, and it was expressed in only three tissues: brain, skeletal ...
Caenorhabditis elegans MIG-13 protein: required for positioning of Q neuroblasts and their descendents along the anteroposterior axis; isolated from Caenorhabditis elegans; amino acid sequence in first source; GenBAnk AF150958
For the first days, we will introduce students to the nematode C. elegans. Students will work with different experimental set-ups that will allow us to explore a variety of C. elegans behavior. We will analyze C. elegans behavior in response to thermal, mechanical and chemical stimuli. The transparency of the animal makes it feasible to use genetically encoded calcium sensors to monitor neural activity in response to sensory stimuli. Transgenic expression of light-activated ion channels, allows us to turn neurons on and off. These optogenetic experiments will be used to define neural requirements of sensory processing. Students will use these techniques to determine 1) how C. elegans responds and remembers the temperature at which was raised; 2) analyze the neural dynamics of a compound motor sequence that is evoked by touch; 3) determine the neural requirements of calcium channels chemosensation. These experiments are an ideal introduction to Calcium imaging optogenetics in a genetically ...
Caenorhabditis elegans shares several molecular and physiological homologies with humans and thus plays a key role in studying biological processes. As a consequence, much progress has been made in automating the analysis of C. elegans. However, there is still a strong need to achieve more progress in automating the analysis of static images of adult worms. In this paper, a three-phase semi-automated system has been proposed. As a first phase, a novel segmentation framework, based on variational level sets and local pressure force function, has been introduced to handle effectively images corrupted with intensity inhomogeneity. Then, a set of robust invariant symbolic features for high-throughput screening of image-based C. elegans phenotypes are extracted. Finally, a classification model is applied to discriminate between the different subsets. The proposed system demonstrates its effectiveness in measuring morphological phenotypes in individual worms of C. elegans.. ...
Genetic studies have identified over a dozen genes that function in programmed cell death (apoptosis) in the nematode Caenorhabditis elegans(1-3). Although the ultimate effects on cell survival or engulfment of mutations in each cell death gene have been extensively described, much less is known about how these mutations affect the kinetics of death and engulfment, or the interactions between these two processes. We have used four-dimensional-Nomarski time-lapse video microscopy to follow in detail how cell death genes regulate the extent and kinetics of apoptotic cell death and removal in the early C. elegans embryo. Here we show that blocking engulfment enhances cell survival when cells are subjected to weak pro-apoptotic signals. Thus, genes that mediate corpse removal can also function to actively kill cells.. ...
A specific behavioural response of Caenorhabditis elegans, the rapid increase of locomotion in response to anoxia/reoxygenation called the O2-ON response, has been used to model key aspects of ischaemia/reperfusion injury. A genetic suppressor screen demonstrated a direct causal role of CYP (cytochrome P450)-13A12 in this response and suggested that CYP-eicosanoids, which in mammals influence the contractility of cardiomyocytes and vascular smooth muscle cells, might function in C. elegans as specific regulators of the body muscle cell activity. In the present study we show that co-expression of CYP-13A12 with the NADPH-CYP-reductase EMB-8 in insect cells resulted in the reconstitution of an active microsomal mono-oxygenase system that metabolized EPA (eicosapentaenoic acid) and also AA (arachidonic acid) to specific sets of regioisomeric epoxy and hydroxy derivatives. The main products included 17,18-EEQ (17,18-epoxyeicosatetraenoic acid) from EPA and 14,15-EET (14,15-epoxyeicosatrienoic acid) ...
Benzimidazole anti-microtubule drugs, such as benomyl, induce paralysis and slow the growth of the nematode Caenorhabditis elegans. We have identified 28 mutations in C. elegans that confer resistance to benzimidazoles. All resistant mutations map to a single locus, ben-1. Virtually all these mutations are genetically dominant. Molecular cloning and DNA sequence analysis established that ben-1 encodes a beta-tubulin. Some resistant mutants are completely deleted for the ben-1 gene. Since the deletion strains appear to be fully resistant to the drugs, the ben-1 product appears to be the only benzimidazole-sensitive beta-tubulin in C. elegans. Furthermore, since animals lacking ben-1 are viable and coordinated, the ben-1 beta-tubulin appears to be nonessential for growth and movement. The ben-1 function is likely to be redundant in the nematode genome. ...
Approximately 10% of Caenorhabditis elegans nervous system synapses are electrical, that is, gap junctions composed of innexins. The locomotory nervous system consists of several pairs of interneurons and three major classes of motor neurons, all with stereotypical patterns of connectivity that include gap junctions. Mutations in the two innexin genes unc-7 and unc-9 result in identical uncoordinated movement phenotypes, and their respective gene products were investigated for their contribution to electrical synapse connectivity. unc-7 encodes three innexin isoforms. Two of these, UNC-7S and UNC-7SR, are functionally equivalent and play an essential role in coordinated locomotion. UNC-7S and UNC-7SR are widely expressed and co-localize extensively with green fluorescent protein-tagged innexin UNC-9 in the ventral and dorsal nerve cords. A subset of UNC-7S/SR expression visualizes gap junctions formed between the AVB forward command interneurons and their B class motor neuron partners. Experiments
Many crucial events in metazoan development and physiology are governed by diffusible signals that trigger specific responses in highly restricted subsets of cells. This exquisite specificity of intercellular signaling requires precisely controlled expression of receptors and downstream signaling components that effect appropriate responses. The nematode Caenorhabditis elegans has proven a valuable model for the study of signaling specificity, notably for mechanisms of signaling through the Epidermal growth factor (EGF) receptor (for a review, see Moghal and Sternberg, 2003). The sole EGF-like ligand and EGF receptor in the C. elegans genome are encoded by the genes lin-3 and let-23, respectively (Hill and Sternberg, 1992; Aroian et al., 1990) (Wormbase WS210). Recently we described a role for LET-23 in the regulation of C. elegans behavior (Van Buskirk and Sternberg, 2007). Caenorhabditis elegans develops through four larval stages before adulthood, and each larval molt is preceded by ...
C. elegans worms. Light microscopy of Caenorhabditis elegans worms. This is a soil-dwelling hermaphrodite nematode worm and one of the most studied animals in biological and genetic research. A tendency to reproduce by self-fertilisation (resulting in identical offspring), along with the short time taken to reach maturity, make this tiny worm an ideal subject. - Stock Video Clip K002/8244
Chromatin modifiers regulate lifespan in several organisms, raising the question of whether changes in chromatin states in the parental generation could be incompletely reprogrammed in the next generation and thereby affect the lifespan of descendants. The histone H3 lysine 4 trimethylation (H3K4me3) complex, composed of ASH-2, WDR-5 and the histone methyltransferase SET-2, regulates Caenorhabditis elegans lifespan. Here we show that deficiencies in the H3K4me3 chromatin modifiers ASH-2, WDR-5 or SET-2 in the parental generation extend the lifespan of descendants up until the third generation. The transgenerational inheritance of lifespan extension by members of the ASH-2 complex is dependent on the H3K4me3 demethylase RBR-2, and requires the presence of a functioning germline in the descendants. Transgenerational inheritance of lifespan is specific for the H3K4me3 methylation complex and is associated with epigenetic changes in gene expression. Thus, manipulation of specific chromatin modifiers ...
Fig. 7 Two-dimensional plot of track curvature versus centroid velocity.. In the drug environment, the worm is classified as active, semiactive, or inactive as demonstrated in Fig. 4, and the plot is accordingly segregated into the three areas of activity. We are primarily interested in combinations that induce inactivity in the worm. (A) In iteration 1, two combinations (that is, P1 and T3) are able to make the worm inactive. Besides in P3, the active worm does not succumb to any other combination and is classified as being active. (B) In iteration 2, only P1 makes the worm inactive. The rest of the combinations do not seem to affect the active worm. (C) In iteration 3, the worm is in a semiactive or active state for all combinations. (D) In iteration 4, three combinations (T1, T2, and T3) are able to make the worm inactive, and the winning combination is chosen as T3. ...
The nematode Caenorhabditis elegans is a genetically tractable model organism to investigate sterol transport. In vivo imaging of the fluorescent sterol, dehydroergosterol (DHE), is challenged by C. elegans high autofluorescence in the same spectral region as emission of DHE. We present a method to detect DHE selectively, based on its rapid bleaching kinetics compared to cellular autofluorescence. Worms were repeatedly imaged on an ultraviolet-sensitive wide field (UV-WF) microscope, and bleaching kinetics of DHE were fitted on a pixel-basis to mathematical models describing the intensity decay. Bleach-rate constants were determined for DHE in vivo and confirmed in model membranes. Using this method, we could detect enrichment of DHE in specific tissues like the nerve ring, the spermateca and oocytes. We confirm these results in C. elegans gut-granule-loss (glo) mutants with reduced autofluorescence and compare our method with three-photon excitation microscopy of sterol in selected tissues. Bleach
The nematode Caenorhabditis elegans is a genetically tractable model organism to investigate sterol transport. In vivo imaging of the fluorescent sterol, dehydroergosterol (DHE), is challenged by C. elegans high autofluorescence in the same spectral region as emission of DHE. We present a method to detect DHE selectively, based on its rapid bleaching kinetics compared to cellular autofluorescence. Worms were repeatedly imaged on an ultraviolet-sensitive wide field (UV-WF) microscope, and bleaching kinetics of DHE were fitted on a pixel-basis to mathematical models describing the intensity decay. Bleach-rate constants were determined for DHE in vivo and confirmed in model membranes. Using this method, we could detect enrichment of DHE in specific tissues like the nerve ring, the spermateca and oocytes. We confirm these results in C. elegans gut-granule-loss (glo) mutants with reduced autofluorescence and compare our method with three-photon excitation microscopy of sterol in selected tissues. Bleach
TY - JOUR. T1 - Caenorhabditis elegans cDNA for a Menkes/Wilson disease gene homologue and its function in a yeast CCC2 gene deletion mutant. AU - Sambongi, Yoshihiro. AU - Wakabayashi, Tokumitsu. AU - Yoshimizu, Takao. AU - Omote, Hiroshi. AU - Oka, Toshihiko. AU - Futai, Masamitsu. PY - 1997/6. Y1 - 1997/6. N2 - The full-length cDNA coding for a putative copper transporting P-type ATPase (Cu2+-ATPase) was cloned from Caenorhabditis elegans. The putative Cu2+-ATPase is a 1,238-amino acid protein, and highly homologous to the Menkes and Wilson disease gene products mutations of which are responsible for human defects of copper metabolism. The Saccharomyces cerevisiae mutant with a disrupted CCC2 gene (yeast Menkes/Wilson disease gene homologue) was rescued by the cDNA for the C. elegans Cu2+-ATPase but not by the cDNA with an Asp-786 (an invariant phosphorylation site) to Asn mutation, suggesting that the C. elegans Cu2+-ATPase functions as a copper transporter in yeast. The expressed C. elegans ...
Mutations in the human Mid1 gene cause Opitz G/BBB syndrome, which is characterized by various midline closure defects. The Caenorhabditis elegans homolog of Mid1, madd-2, positively regulates signaling by the unc-40 Netrin receptor during the extension of muscle arms to the midline and in axon guidance and branching. During uterine development, a specialized cell called anchor cell (AC) breaches the basal laminae separating the uterus from the epidermis and invades the underlying vulval tissue. AC invasion is guided by an UNC-6 Netrin signal from the ventral nerve cord and an unknown guidance signal from the vulval cells. Using genetic epistasis analysis, we show that madd-2 regulates AC invasion downstream of or in parallel with the Netrin signaling pathway. Measurements of AC shape, polarity and dynamics indicate that MADD-2 prevents the formation of ectopic AC protrusions in the absence of guidance signals. We propose that MADD-2 represses the intrinsic invasive capacity of the AC, while the ...
In nematodes an alternative third larval stage, often called the dauer stage, allows the animals to weather periods of low food availability (if free living) or to disperse (if parasitic). Recently, studies of mutations in the nematode Caenorhabditis elegans have indicated that mutations in age-1 and daf-2 , genes that control the entry into and exit from the dauer stage, have a profound effect upon the life span of the animal. Catalase activity is increased in age-1 and daf-2 animals and might be important for life-span extension. We show that C. elegans contains two catalases, CTL-2 is a typical animal peroxisomal catalase. The ctl-1 gene encodes the first cytosolic catalase identified in an animal. The ctl-1 catalase is regulated by age-1 and daf-2 and is responsible for the increase in catalase activity seen in these mutants. We have identified a mutation affecting the expression of ctl-1. The ctl-1 mutation causes the early death of dauer larvae and prevents the life-span extension of the ...
The prototype of the Cdx family of homeodomain transcription factors is the Drosophila caudal protein. The initial maternal expression of caudal mRNA is ubiquitous and a posterior to anterior gradient of the protein develops during the syncytial blastoderm stage and persists until the onset of cellularization. Zygotic expression, which commences in the cellular blastoderm stage, is also localized to the posterior in a region which gives rise to terminal abdominal structures and the hindgut. During later embryonic development, expression of caudal is found in the midgut, hindgut and Malpigian tubules (MacDonald and Struhl, 1986; Mlodzik and Gehring, 1987).. Caudal homologues have been identified in a wide range of animal groups. A caudal‐related gene with a similar posterior expression pattern has been cloned from the short or intermediate germ band insect Bombyx mori and homologues are present in other invertebrates, including the nematode worm Caenorhabditis elegans and the annelid worm ...
Howard Robert Horvitz (born May 8, 1947) is an American biologist best known for his research on the nematode worm Caenorhabditis elegans, for which he was awarded the 2002 Nobel Prize in Physiology or Medicine, together with Sydney Brenner and John E. Sulston. Horvitz was born in Chicago, Illinois to Jewish parents, the son of Mary R. (Savit), a school teacher, and Oscar Freedom Horvitz, a GAO accountant. He majored in mathematics at Massachusetts Institute of Technology, where he joined Alpha Epsilon Pi and spent his summers working for IBM, at first wiring panels for accounting machines and then in his final summer helping to develop IBMs Conversational Programming System. During his senior year, Horvitz took his first courses in biology and was encouraged by his professors to continue to study biology in graduate school, despite his limited coursework in the field. After he completed his undergraduate studies in 1968, he enrolled in graduate studies in biology at Harvard University, where ...
The role of lipids in the process of embryonic development of Caenorhabditis elegans is still poorly understood. Cytochrome P450s, a class of lipid-modifying enzymes, are good candidates to be involved in the production or degradation of lipids essential for development. We investigated two highly similar cytochrome P450s in C. elegans, cyp-31A2 and cyp-31A3, that are homologs of the gene responsible for Bietti crystalline corneoretinal dystrophy in humans. Depletion of both cytochromes either by RNAi or using a double deletion mutant, led to the failure of establishing the correct polarity of the embryo and to complete the extrusion of the polar bodies during meiosis. In addition, the egg became osmotic sensitive and permeable to dyes. The phenotype of cyp-31A2 or cyp-31A3 is very similar to a class of mutants that have polarization and osmotic defects (POD), thus the genes were renamed to pod-7 and pod-8, respectively. Electron microscopic analysis demonstrated that the activity of pod-7/pod-8 ...
Aims: To investigate the role of endogenous hydrogen sulfide (H2S) in the control of aging and healthspan of Caenorhabditis elegans. Results: We show that the model organism, C. elegans, synthesizes H2S. Three H2S-synthesizing enzymes are present in C. elegans, namely cystathionine γ lyase (CSE), cystathionine β synthetase, and 3-mercaptopyruvate transferase (MPST or 3-MST). Genetic deficiency of mpst-1 (3-MST orthologue 1), but not cth-2 (CSE orthologue), reduced the lifespan of C. elegans. This effect was reversed by a pharmacological H2S donor (GYY4137). GYY4137 also reduced detrimental age-dependent changes in a range of physiological indices, including pharyngeal contraction and defecation. Treatment of C. elegans with GYY4137 increased the expression of several age-related, stress response, and antioxidant genes, whereas MitoSOX Red fluorescence, indicative of reactive oxygen species generation, was increased in mpst-1 knockouts and decreased by GYY4137 treatment. GYY4137 additionally ...
The Caenorhabditis elegans run gene encodes a Runt domain factor. Runx1, Runx2, and Runx3 are the three known mammalian homologs of run. Runx1, which plays an essential role in hematopoiesis, has been identified at the breakpoint of chromosome translocations that are responsible for human leukemia. Runx2 plays an essential role in osteogenesis, and inactivation of one allele of Runx2 is responsible for the human disease cleidocranial dysplasia. To understand the role of run in C. elegans, we used transgenic run::GFP reporter constructs and a double-stranded RNA-mediated interference method. The expression of run was detected as early as the bean stage exclusively in the nuclei of seam hypodermal cells and lasted until the L3 stage. At the larval stage, expression of run was additionally detected in intestinal cells. The regulatory elements responsible for the postembryonic hypodermal seam cells and intestinal cells were separately located within a 7.2-kb-long intron region. This is the first ...
Caenorhabditis elegans are free-living bacterivorous nematodes that naturally consume bacteria as food source. As an excellent genetic model, C. elegans has proven to be a successful system to study innate immune responses to human pathogens, which resulted in identification of many evolutionarily conserved defense pathways. Most of these studies examined innate immune pathway mutants in a single genetic background in response to monoculture of human pathogens that worms might not necessarily encounter in the wild. While this has led to the successful genetic dissection of these defense pathways, in order to fully understand their biological functions, the relevant ecological and evolutionary context needs to be taken into account. The bacterial environment C. elegans naturally encounter is likely to be highly heterogeneous. While many bacteria are mainly considered as dietary resource for worms, some could be potential pathogens. Worms thus constantly face the challenge to defend against the ...
Turraea fischeri is an East African traditional herb, which is widely used in traditional medicine. In this study, we profiled the secondary metabolites in the methanol extract of T. fischeri bark using HPLC-PDA-ESI-MS/MS, and 20 compounds were tentatively identified. Several isomers of the flavonolignan cinchonain-I and bis-dihydroxyphenylpropanoid-substituted catechin hexosides dominated the extract. Robust in vitro and in vivo antioxidant properties were observed in 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay (DPPH) and ferric reducing antioxidant power (FRAP) assay, and in the model organism Caenorhabditis elegans. Additionally, the extract exhibited promising hepatoprotective activities in D-galactosamine (D-GaIN) treated rats. A significant reduction in the elevated levels of aspartate aminotransferase (AST), total bilirubin, gamma-glutamyltransferase (GGT), and malondialdehyde (MDA) and increase of glutathione (GSH) was observed in rats treated with the bark extract in addition to D
The nematode Caenorhabditis elegans has been much studied as a host for microbial infection. Some pathogens can infect its intestine, while others attack via its external surface. Cultures of Caenorhabditis isolated from natural environments have yielded new nematode pathogens, such as microsporidia and viruses. We report here a novel mechanism for bacterial attack on worms, discovered during investigation of a diseased and coinfected natural isolate of Caenorhabditis from Cape Verde. Two related coryneform pathogens (genus Leucobacter) were obtained from this isolate, which had complementary effects on C. elegans and related nematodes. One pathogen, Verde1, was able to cause swimming worms to stick together irreversibly by their tails, leading to the rapid formation of aggregated worm-stars. Adult worms trapped in these aggregates were immobilized and subsequently died, with concomitant growth of bacteria. Trapped larval worms were sometimes able to escape from worm-stars by undergoing autotomy,
The elt-1 RNAi phenotype provides a useful insight into the function of seam cells during postembryonic development. The loss of alae in the adult cuticle confirms the role of seam cells in producing this structure, which has previously been shown by laser ablation studies (Singh and Sulston, 1978). The apparently normal appearance of the underlying cuticle is also consistent with these previous studies and presumably this is derived from the dorsal/ventral hypodermis. RNAi of elt-1, applied during larval development, has a severe effect on the integrity of adult worms within a few hours of the L4-adult moult. Adult hermaphrodites show a `burst-vulva phenotype, in which the uterus herneates through the vulva. This is likely to be a direct consequence of seam-cell loss because the lateral seam anchors the vulval and uterine cells in position by virtue of the utse cell connection (Michaux et al., 2001; Newman et al., 2000; Sharma-Kishore et al., 1999). This hypothesis is supported by the ...
TY - JOUR. T1 - Regulation of Tcl transposable elements in Caenorhabditis elegans.. AU - Emmons, S. W.. AU - Ruan, K. S.. AU - Levitt, A.. AU - Yesner, L.. PY - 1985. Y1 - 1985. N2 - C. elegans strains contain variable numbers of a 1.6-kb transposable genetic element. Activity of this element, which is denoted Tcl, shows regulation at at least two levels. At one level, excision of Tcl elements occurs in somatic cells at a frequency several orders of magnitude higher than in germ cells. Evidence is presented suggesting that this results from regulation at the level of trans-acting functions that are required for excision or that repress excision. At the second level, germ line transposition of Tcl occurs at greater frequency in some strains than in others. The hypothesis is proposed that this is because Tcl is one component of a two-element system, the second element of which differs between strains. Evidence for a second putative transposable element family in C. elegans is presented. This ...
The Caenorhabditis elegans Regulator of Presynaptic Morphology (RPM)-1 is a member of a conserved family of proteins called Pam/Highwire/RPM-1 (PHR) proteins. PHR proteins are key regulators of neuronal development. In C. elegans, RPM-1 (regulator of presynaptic morphology-1) regulates axon termination and guidance in the mechanosensory neurons, and regulates synapse formation in the mechanosensory and motor neurons (Po et al., 2010). In adult C. elegans, RPM-1 also plays a role in axon regeneration in motor neurons (Hammarlund et al., 2009). Importantly, Drosophila Highwire, zebrafish Esrom/Phr1, and murine Phr1 also regulate synapse formation and axon extension highlighting the evolutionarily conserved function of the PHR proteins (Po et al., 2010).. Previous studies showed that RPM-1 functions, in part, as an E3 ubiquitin ligase by binding to the F box SyNaptic protein (FSN)-1 and negatively regulating a MAPK pathway that includes: the Dual Leucine zipper-bearing Kinase (DLK)-1, MAPK Kinase ...
Under experimental conditions, virtually all behaviors of Caenorhabditis elegans are achieved by combinations of simple locomotion, including forward, reversal movement, turning by deep body bending, and gradual shallow turning. To study how worms regulate these locomotion in response to sensory information, acidic pH avoidance behavior was analyzed by using worm tracking system. In the acidic pH avoidance, we characterized two types of behavioral maneuvers that have similar behavioral sequences in chemotaxis and thermotaxis. A stereotypic reversal-turn-forward sequence of reversal avoidance caused an abrupt random reorientation, and a shallow gradual turn in curve avoidance caused non-random reorientation in a less acidic direction to avoid the acidic pH. Our results suggest that these two maneuvers were each triggered by a distinct threshold pH. A simulation study using the two-distinct-threshold model reproduced the avoidance behavior of the real worm, supporting the presence of the threshold.
Neuropeptides regulate all aspects of behavior in multicellular organisms. Because of their ability to act at long distances, neuropeptides can exert their effects beyond the conventional synaptic connections, thereby adding an intricate layer of complexity to the activity of neural networks. In the nematode Caenorhabditis elegans, a large number of neuropeptide genes that are expressed throughout the nervous system have been identified.The actions of these peptides supplement the synaptic connections of the 302 neurons, allowing for fine tuning of neural networks and increasing the ways in which behaviors can be regulated. In this review, we focus on a large family of genes encoding FMRFamide-related peptides (FaRPs). These genes, the flp genes, have been used as a starting point to identifying flp genes throughout Nematoda. Nematodes have the largest family of FaRPs described thus far. The challenges in the future are the elucidation of their functions and the identification of the receptors and
Metals are major contaminants that influence human health. Many metals have physiologic roles, but excessive levels can be harmful. Advances in technology have made toxicogenomic analyses possible to characterize the effects of metal exposure on the entire genome. Much of what is known about cellular responses to metals has come from mammalian systems; however the use of non-mammalian species is gaining wider attention. Caenorhabditis elegans (C. elegans) is a small round worm whose genome has been fully sequenced and its development from egg to adult is well characterized. It is an attractive model for high throughput screens due to its short lifespan, ease of genetic mutability, low cost and high homology with humans. Research performed in C. elegans has led to insights in apoptosis, gene expression and neurodegeneration, all of which can be altered by metal exposure. Additionally, by using worms one can potentially study how the mechanisms that underline differential responses to metals in nematodes
The eukaryotic ubiquitin-conjugation system sets the turnover rate of many proteins and includes activating enzymes (E1s), conjugating enzymes (UBCs/E2s), and ubiquitin-protein ligases (E3s), which are responsible for activation, covalent attachment and substrate recognition, respectively. There are also ubiquitin-like proteins with distinct functions, which require their own E1s and E2s for attachment. We describe the results of RNA interference (RNAi) experiments on the E1s, UBC/E2s and ubiquitin-like proteins in Caenorhabditis elegans. We also present a phylogenetic analysis of UBCs. The C. elegans genome encodes 20 UBCs and three ubiquitin E2 variant proteins. RNAi shows that only four UBCs are essential for embryogenesis: LET-70 (UBC-2), a functional homolog of yeast Ubc4/5p, UBC-9, an ortholog of yeast Ubc9p, which transfers the ubiquitin-like modifier SUMO, UBC-12, an ortholog of yeast Ubc12p, which transfers the ubiquitin-like modifier Rub1/Nedd8, and UBC-14, an ortholog of Drosophila Courtless.
We report the discovery of a checkpoint that monitors synapsis between homologous chromosomes to ensure accurate meiotic segregation. Oocytes containing unsynapsed chromosomes selectively undergo apoptosis even if a germline DNA damage checkpoint is inactivated. This culling mechanism is specifically activated by unsynapsed pairing centers, cis-acting chromosome sites that are also required to promote synapsis in Caenorhabditis elegans. Apoptosis due to synaptic failure also requires the C. elegans homolog of PCH2, a budding yeast pachytene checkpoint gene, which suggests that this surveillance mechanism is widely conserved.. ...
The nematode Caenorhabditis elegans has in recent years been proven to be a powerful in vivo model for testing antimicrobial compounds. We report here that the alkaloid compound Harmane (2-methyl-β-carboline) increases the lifespan of nematodes infected with a human pathogen, the Shiga toxin-producing Escherichia coli O157:H7 strain EDL933 and several other bacterial pathogens. This was shown to be unrelated to the weak antibiotic effect of Harmane. Using GFP-expressing E. coli EDL933, we showed that Harmane does not lower the colonization burden in the nematodes. We also found that the expression of the putative immune effector gene F35E12.5 was up-regulated in response to Harmane treatment. This indicates that Harmane stimulates the innate immune response of the nematode; thereby increasing its lifespan during bacterial infection. Expression of F35E12.5 is predominantly regulated through the p38 MAPK pathway; however, intriguingly the lifespan extension resulting from Harmane was higher in ...
An additional genetic locus in Caenorhabditis elegans, unc-116, was identified in a screen for mutations resulting in defective locomotion. unc-116 was cloned by use of a transposon insertion mutant and the physical and genetic map of the genome. The cDNA sequence predicts an 815-amino acid protein. Based upon sequence comparison and secondary structure predictions, unc-116 encodes all three domains of the kinesin heavy chain: the motor, stalk, and tail. While the motor and tail domains have a high degree of identity to the equivalent domains of cloned kinesin heavy chains, the rodII domain of the stalk is significantly shorter than those previously reported and is not predicted to form a coiled-coil alpha-helix. Analysis of mutational defects in two C. elegans genes encoding anterograde motor molecules, unc-116 and unc-104, should provide insight into the in vivo functions of these members of the kinesin heavy chain superfamily.. ...
TY - JOUR. T1 - A novel calcineurin-interacting protein, CNP-3, modulates calcineurin deficient phenotypes in Caenorhabditis elegans. AU - Kim, Yun Hee. AU - Song, Hyun Ok. AU - Ko, Kyung Min. AU - Singaravelu, Gunasekaran. AU - Jee, Chang Hoon. AU - Kang, Junsu. AU - Ahnn, Joohong. PY - 2008/6/30. Y1 - 2008/6/30. N2 - Calcineurin (Cn) is a calcium/calmodulin-dependent serine/threonine protein phosphatase that has diverse functions in different cell types and organisms. We screened proteins interacting with the C. elegans CnA homolog, TAX-6, by the yeast two-hybrid system. CNP-3 (Calcineurin interacting protein-3) is a novel protein that physically interacts with the catalytic domain of TAX-6. It is strongly expressed in the nuclei of intestine, hypodermis, dorsal uterine regions and spermatheca. Expression begins around the 60-cell stage and proceeds during all larval stages and the adult. To elucidate the biological function of cnp-3 we isolated a cnp-3 deletion mutant. Since CNP-3 binds CnA, ...
This paper presents a simple yet biologicallygrounded model for the neural control of Caenorhabditis elegans forward locomotion. We identify a minimal circuit within the C. elegans ventral cord that is likely to be sufficient to generate and sustain forward locomotion in vivo. This limited subcircuit appears to contain no obvious central pattern generated control. For that subcircuit, we present a model that relies on a chain of oscillators along the body which are driven by local and proximate mechano-sensory input. Computer simulations were used to study the model under a variety of conditions and to test whether it is behaviourally plausible. Within our model, we find that a minimal circuit of AVB interneurons and B-class motoneurons is sufficient to generate and sustain fictive forward locomotion patterns that are robust to significant environmental perturbations. The model predicts speed and amplitude modulation by the AVB command interneurons. An extended model including D-class ...
Despite the prominence of Caenorhabditis elegans as a major developmental and genetic model system, its phylogenetic relationship to its closest relatives has not been resolved. Resolution of these relationships is necessary for studying the steps that underlie life history, genomic, and morphological evolution of this important system. By using data from five different nuclear genes from 10 Caenorhabditis species currently in culture, we find a well resolved phylogeny that reveals three striking patterns in the evolution of this animal group: (i) Hermaphroditism has evolved independently in C. elegans and its close relative Caenorhabditis briggsae; (ii) there is a large degree of intron turnover within Caenorhabditis, and intron losses are much more frequent than intron gains; and (iii) despite the lack of marked morphological diversity, more genetic disparity is present within this one genus than has occurred within all vertebrates. ...
Progressive neuronal deterioration accompanied by sensory functions decline is typically observed during aging. On the other hand, structural or functional alterations of specific sensory neurons extend lifespan in the nematode Caenorhabditis elegans. Hormesis is a phenomenon by which the body benefits from moderate stress of various kinds which at high doses are harmful. Several studies indicate that different stressors can hormetically extend lifespan in C. elegans and suggest that hormetic effects could be exploited as a strategy to slow down aging and the development of age-associated (neuronal) diseases in humans. Mitochondria play a central role in the aging process and hormetic-like bimodal dose-response effects on C. elegans lifespan have been observed following different levels of mitochondrial stress. Here we tested the hypothesis that mitochondrial stress may hormetically extend C. elegans lifespan through subtle neuronal alterations. In support of our hypothesis we find that life-lengthening
The C. elegans hermaphrodite vulva develops during postembryonic (larval) development from ventral epidermal precursors, and connects the developing uterus to the external environment. In the adult, the vulva is necessary for egg-laying (see Egg-laying) and for copulation with males (see Male mating behavior). Vulval development has attracted general interest for three main reasons. First, it serves as a paradigm for organogenesis. In particular, vulva development represents a well-understood case in which invariant development arises from multiple cell-cell interactions. It is also a striking example of tissue remodeling: the formation of a hole at a precise location in an organism. Second, it has been important for the genetic analyses of signaling and signal transduction by epidermal growth factor (EGF)-receptor LET-23 and RAS LET-60; (see RTKRas/MAP kinase signaling), LIN-12 (see LIN-12/Notch signaling in C. elegans), and WNT (see Wnt signaling), as well as the functions of the SynMuv and ...
The C. elegans hermaphrodite vulva develops during postembryonic (larval) development from ventral epidermal precursors, and connects the developing uterus to the external environment. In the adult, the vulva is necessary for egg-laying (see Egg-laying) and for copulation with males (see Male mating behavior). Vulval development has attracted general interest for three main reasons. First, it serves as a paradigm for organogenesis. In particular, vulva development represents a well-understood case in which invariant development arises from multiple cell-cell interactions. It is also a striking example of tissue remodeling: the formation of a hole at a precise location in an organism. Second, it has been important for the genetic analyses of signaling and signal transduction by epidermal growth factor (EGF)-receptor LET-23 and RAS LET-60; (see RTKRas/MAP kinase signaling), LIN-12 (see LIN-12/Notch signaling in C. elegans), and WNT (see Wnt signaling), as well as the functions of the SynMuv and ...
Multiphoton laser scanning microscopy (MPLSM) enables the production of long timelapse recordings from live fluorescent specimens. 1047- and 900-nm excitation were used to image both a vital fluorescent membrane probe, FM 4-64, and a modified green fluorescent protein (GFP) in live Caenorhabditis elegans embryos. Automated four-dimensional (4D) data collection yielded individual recordings comprising thousands of images, each allowing analysis of all of the cell divisions, contacts, migrations, and fusions that occur during a span of several hours of embryogenesis.. ©1998 Optical Society of America. Full Article , PDF Article ...
Current Name: Aphyosemion elegans. Describer(s), Year: (Boulenger, 1899). IDENTITY: elegans A.. Family-group Names: Nothobranchiidae Garman, 1895 , Nothobranchiinae Garman, 1895 , Nothobranchiini Garman, 1895 , Aphyosemina Huber, 2000 (#Aphyosemiina #Aphyosemionina) Genus: Aphyosemion Myers, 1924. Subgenus: Aphyosemion Myers, 1924. Abbreviated genus: A.. Abbreviated subgenus: (A.). Species: elegans. Index name: elegans: Aphyosemion elegans. Full name: Aphyosemion (Aphyosemion) elegans. TYPOLOGY: elegans A.. Original name: Haplochilus elegans. Describer(s): Boulenger. Year of description: 1899. Original description: Boulenger, G.A. 1899. Poissons nouveaux du Congo. Cinquième Partie. Cyprins, Silures, Cyprinodontes, Acanthopterygiens. Ann. Mus. Congo Belge, Tervuren, Zool. Ser., 1 (5): 113, pl. 47 (fig. 2).. Gender/Accordance: [Subst.]. SYSTEMATICS: elegans A.. Current status: valid sp.. Status evaluation (current): discussed {no red bars on male sides are mentioned in the description, only -red- ...
0, Molecular and genetic characterization of GON-2, a TRPM cation channel required for gonadogenesis in Caenorhabditis elegans A Thesis Submitted to the Faculty in partial fulfillment of the requirements for the degree of o Doctor of Philosophy in Biological Sciences by Rachel West DARTMOUTH COLLEGE Hanover, New Hampshire January, 2004 Examining9ommittee: Eric }. IAInbig (Chair) c:, Victor R. A)fibros Eleanor M. Maine Carol L. Folt Dean of Graduate Studies ...
Phosphine is a fumigant used to protect stored commodities from infestation by pest insects, though high-level phosphine resistance in many insect species threatens the continued use of the fumigant. The mechanisms of toxicity and resistance are not clearly understood. In this study, the model organism, Caenorhabditis elegans, was employed to investigate the effects of phosphine on its proposed in vivo target, the mitochondrion. We found that phosphine rapidly perturbs mitochondrial morphology, inhibits oxidative respiration by 70%, and causes a severe drop in mitochondrial membrane potential ({Delta}{Psi}m) within 5 h of exposure. We then examined the phosphine-resistant strain of nematode, pre-33, to determine whether resistance was associated with any changes to mitochondrial physiology. Oxygen consumption was reduced by 70% in these mutant animals, which also had more mitochondrial genome copies than wild-type animals, a common response to reduced metabolic capacity. The mutant also had an ...
We have examined the cortex of Caenorhabditis elegans eggs during pseudocleavage (PC), a period of the first cell cycle which is important for the generation of asymmetry at first cleavage (Strome, S. 1989. Int. Rev. Cytol. 114: 81-123). We have found that directed, actin dependent, cytoplasmic, and cortical flow occurs during this period coincident with a rearrangement of the cortical actin cytoskeleton (Strome, S. 1986. J. Cell Biol. 103: 2241-2252). The flow velocity (4-7 microns/min) is similar to previously determined particle movements driven by cortical actin flows in motile cells. We show that directed flows occur in one of the daughters of the first division that itself divides asymmetrically, but not in its sister that divides symmetrically. The cortical and cytoplasmic events of PC can be mimicked in other cells during cytokinesis by displacing the mitotic apparatus with the microtubule polymerization inhibitor nocodazole. In all cases, the polarity of the resulting cortical and ...
Glutathione is the most abundant thiol in the vast majority of organisms and is maintained in its reduced form by the flavoenzyme glutathione reductase. In this work, we describe the genetic and functional analysis of the Caenorhabditis elegans gsr-1 gene that encodes the only glutathione reductase protein in this model organism. By using green fluorescent protein reporters we demonstrate that gsr-1 produces two GSR-1 isoforms, one located in the cytoplasm and one in the mitochondria. gsr-1 loss of function mutants display a fully penetrant embryonic lethal phenotype characterized by a progressive and robust cell division delay accompanied by an aberrant distribution of interphasic chromatin in the periphery of the cell nucleus. Maternally expressed GSR-1 is sufficient to support embryonic development but these animals are short-lived, sensitized to chemical stress and have increased mitochondrial fragmentation and lower mitochondrial DNA content. Furthermore, the embryonic lethality of gsr-1 ...
The protease separase plays a key role in sister chromatid disjunction and centriole disengagement. To maintain genomic stability, separase activity is strictly regulated by binding of an inhibitory protein, securin. Despite its central role in cell division, the separase and securin complex is poorly understood at the structural level. This is partly owing to the difficulty of generating a sufficient quantity of homogeneous, stable protein. Here, we report the production of Caenorhabditis elegans separase-securin complex, and its characterization using biochemical methods and by negative staining electron microscopy. Single particle analysis generated a density map at a resolution of 21-24 Å that reveals a close, globular structure of complex connectivity harbouring two lobes. One lobe matches closely a homology model of the N-terminal HEAT repeat domain of separase, whereas the second lobe readily accommodates homology models of the separase C-terminal death and caspase-like domains. The ...
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Existing models for C. elegans locomotion (Niebur and Erdös, 1993; Bryden and Cohen, 2008; Karbowski et al., 2008) address only forward locomotion during crawling. In all of these models, VB and DB are the sources of alternating activity to ventral and dorsal muscle. We were not able to discern any such alternating activity between pairs of VB and DB motoneurons that innervate contralateral muscle cells. If alternating motoneuron activity does occur, then one of several reasons may account for our failure to detect it. First, the activity of motoneurons at the recording site might be affected by the tethering. In addition, the decay time constant of YC2.60 we used to detect calcium changes accompanying forward and backward locomotion was too slow (5.2 s) (Hendel et al., 2008) to allow us to resolve the faster oscillatory signals. Although YC3.60 has a faster decay time constant, the signals it generated were consistently smaller than YC2.60 and fast rhythmic signals accompanying sinusoidal ...
The overall strategy is to employ a well-characterized soil organism to probe the regulation of a key gene in metal detoxification and homeostasis. The aim of the research is to identify metal regulatory elements (MREs) within the promoters of two C. elegans MT genes, and isolate and characterize proteins that interact with the candidate MREs. Candidate MREs will be identified by site-directed mutagenesis and deletion experiments. The functional significance of each modification will be determined in vivo (inside the organism) by creating transgenic nematodes containing a ß-galactosidase reporter gene. Changes in the level of pattern of reporter gene activity in cadmium-exposed nematodes will be used to identity functional promoter elements. Metal-dependent interaction of crude extract proteins with candidate MREs will be evaluated by gel mobility shift assay and DNaseI footprinting. Regulatory proteins that interact with candidate MREs will be isolated from extracts prepared from control and ...
In this study, we have shown that the C. elegans PRKs are true orthologs for the mammalian PIM family kinases, as demonstrated by comparison of the properties of PIM-1, PRK-1 and PRK-2. Based on our in vitro kinase assay data, PRKs are able to target also such known PIM substrates as NFATC1, which are not expressed in C. elegans, confirming the functional conservation of the enzymatic activity. The amino acid sequences within the kinase domains of PIMs and PRKs are highly conserved, especially at the ATP-binding site and the catalytically active site. However, the sequences of different lengths outside the kinase domains do not show any homology between the mammalian and C. elegans proteins, and are not conserved between PRK-1 and PRK-2, either. Thus, these sequences may allow more individual interactions of distinct PRK family members with other proteins.. The catalytic activity of the mammalian PIM kinases can be blocked by selective ATP-competitive inhibitors, such as DHPCC-9. Crystallization ...
  • Although more than half of the newfound C. elegans genes have no identified function, researchers plan to inactivate every gene to understand its role in the nematode. (apsnet.org)
  • In a screen for genes that modulate C. elegans insulin-like signaling, we identified eak-3, which encodes a novel protein that is specifically expressed in the two endocrine XXX cells. (unboundmedicine.com)
  • We predict that as many as 887 (4.4%) of C. elegans genes may encode RBPs ~250 of which likely function in a gene-specific manner. (umassmed.edu)
  • A compendium of Caenorhabditis elegans RNA binding proteins predicts e" by Alex M. Tamburino, Sean P. Ryder et al. (umassmed.edu)
  • On the premise that C. elegans is a 'model nematode' with respect to many aspects of neural function, the intention is that this might inform a broader understanding of the role of these channels in the nematodes and their potential as novel anthelmintic targets. (soton.ac.uk)
  • Ageing in nematodes: Do antioxidants extend lifespan in Caenorhabditis elegans? (nus.edu.sg)
  • AAK-2 is one of two α isoforms of the AMP-activated protein kinase in Caenorhabditis elegans and is involved in life span maintenance, stress responses, and germ cell cycle arrest upon dauer entry. (elsevier.com)
  • Caenorhabditis elegans embryo at 1.5-fold stage inside egg. (apsnet.org)
  • The genome sequence of Caenorhabditis elegans reveals the presence of a non-LTR retrotransposon that resembles the older elements, in that it contains a single open reading frame with a carboxyl-terminal restriction-like endonuclease domain. (unboundmedicine.com)
  • In the nematode Caenorhabditis elegans, insulin-like signaling functions in larvae to inhibit dauer arrest and acts during adulthood to regulate lifespan. (unboundmedicine.com)
  • Laboratory adapted Escherichia coli K-12 becomes a pathogen of Caenorhabditis elegans upon restoration of O antigen biosynthesis. (docphin.com)
  • Recently, the free-living nematode Caenorhabditis elegans (FIGURES 1,3-6) became the first animal and more importantly, the first multicellular organism, to have the sequencing of its genome essentially completed ( C. elegans Consortium, Science 282:2011-2045, 1998). (apsnet.org)
  • Importantly, O antigen production enables laboratory strains of E. coli to enter the gut of the Caenorhabditis elegans worm and to kill C. elegans at rates similar to pathogenic bacterial species. (docphin.com)
  • Our study suggests that AMPK can influence the behavior of C. elegans worms in addition to its well known function in metabolic control. (elsevier.com)
  • These results suggest C. elegans is not an effective model of human-pathogenic E. coli infectious disease. (docphin.com)
  • Ei sekvensering av genomet til C. elegans på kring 97 megabasepar vart publisert i 1998 og gjorde C. elegans til den fyrste fleirsella organismen som fekk genomet sitt sekvensert. (wikipedia.org)
  • The C. elegans Sequencing Consortium (1998). (wikipedia.org)
  • We found that AAK-2 was phosphorylated at threonine 243 in response to paraquat treatment and that this phosphorylation depends on PAR-4, the C. elegans LKB1 homologue. (elsevier.com)
  • The dauer arrest phenotype of eak-3 mutants is fully suppressed by mutations in daf-16/FoxO, which encodes the major target of C. elegans insulin-like signaling, and daf-12, which encodes a nuclear receptor regulated by steroid hormones known as dafachronic acids. (unboundmedicine.com)
  • Both aak-2 mutation and par-4 knockdown increased the sensitivity of C. elegans worms to paraquat, and the double deficiency did not further increase sensitivity, indicating that aak-2 and par-4 act in a linear pathway. (elsevier.com)
  • Caenorhabditis elegans adult and two juveniles. (apsnet.org)
  • In particular, we focus on the role of SLO-1 in the regulation of Caenorhabditis elegans behaviour and highlight the role of this channel as an effector for pleiotropic actions of neuroactive drugs, including emodepside. (soton.ac.uk)
  • Full-genome RNAi profiling of early embryogenesis in Caenorhabditis elegans . (nature.com)
  • many studies focused initially on Caenorhabditis elegans , since this model organism has a relatively small genome amenable to basic genetic research. (britannica.com)
  • The genome of C. elegans is approximately 100 million base pairs, whereas the human genome consists of more than 3 billion. (britannica.com)
  • Caenorhabiditis elegans is a free-living (non- parasitic ) species of soil nematode which makes a good model organism for biological study because it has a small genome of only six chromosome s. (everything2.com)
  • Complete sequencing of the genome of C. elegans indicated that at least 36% of the 19,000 predicted proteins have matches in humans ( 1 ). (pnas.org)
  • The complete sequencing of C . elegans genome was completed in 2002. (hindawi.com)
  • For the first time, in this work, we have analyzed the different types of sequences belonging to the genome of C . elegans , focusing our investigation on those that show fractal characteristics. (hindawi.com)
  • The key attributes of C. elegans as an experimental system for biological systems are its simplicity, transparency, ease of cultivation in the laboratory, short life cycle, suitability of genetic analysis and small genome size. (citizendium.org)
  • The C. elegans has a small genome, yet a very complex one. (citizendium.org)
  • Analysis of this expanded and corrected data set suggested that the high A/U content of C. elegans 3'UTRs facilitated genome compaction, because the elements specifying cleavage and polyadenylation, which are A/U rich, can more readily emerge in A/U-rich regions. (nih.gov)
  • C. elegans was the first multicellular organism to have its whole genome sequenced. (ravelry.com)
  • Caenorhabditis elegans is a small round worm whose genome has been fully sequenced and its development from egg to adult is well characterized. (frontiersin.org)
  • By cDNA library screening, bioinformatic searches, and genome/transcriptome data mining for proteins with Arg-Phe-Gly sequences flanked by N- and C-terminal tri-, di-, or mono-basic residues, we and others identified 31 genes encoding FLPs in C. elegans ( 10 , 12 ). (frontiersin.org)
  • Recently, the free-living nematode Caenorhabditis elegans (FIGURES 1,3-6) became the first animal and more importantly, the first multicellular organism, to have the sequencing of its genome essentially completed ( C. elegans Consortium, Science 282:2011-2045, 1998). (apsnet.org)
  • The Caenorhabditis elegans genome sequencing project, a collaboration between Robert Waterston's group in St. Louis and John Sulston's group in Cambridge, is currently on schedule towards its goal of obtaining the complete sequence of this organism and all its estimated 15,000 to 20,000 genes by 1998 (Sulston et al. (springer.com)
  • The Caenorhabditis elegans genome contains monomorphic minisatellites and simple sequences. (colorado.edu)
  • Here we demonstrate the presence of sequences in the genome of the nematode Caenorhabditis elegans which are homologous to two sets of short sequence DNA. (colorado.edu)
  • Addgene: Transgene-Free Genome Editing in Caenorhabditis elegans Using CRISPR-Cas. (addgene.org)
  • We employ state-of-the-art machine learning methods to assay and improve the accuracy of the genome annotation of the nematode Caenorhabditis elegans. (caltech.edu)
  • Notably, only 37% and 50%, respectively, of the presently unconfirmed genes in the C. elegans genome annotation agree with our predictions, thus we hypothesize that a sizable fraction of those genes are not correctly annotated. (caltech.edu)
  • We conclude that the genome annotation of C. elegans and other organisms can be greatly enhanced using modern machine learning technology. (caltech.edu)
  • To gain insights into the host defense responses to B. pseudomallei infection within the context of a whole organism, we performed a genome-wide transcriptome analysis on infected Caenorhabditis elegans. (omicsonline.org)
  • We used RNA-mediated interference to target 98% of all genes predicted in the C. elegans genome in combination with differential interference contrast time-lapse microscopy. (epfl.ch)
  • Using a genome-wide association study in C. elegans wild populations and quantitative trait locus mapping, we identify a 159 base-pair deletion in the conserved drh-1 gene (encoding a RIG-I-like helicase) as a major determinant of viral sensitivity. (ens.fr)
  • Many candidate antimicrobial genes have been identified in the C. elegans genome ( 17 , 40 , 46 ). (asm.org)
  • To better understand how these genes function in host defense, we have undertaken a study of a large, representative sample of candidate antimicrobial genes encoded in the C. elegans genome (Table 1 ). (asm.org)
  • studies centred on the nematode Caenorhabditis elegans , a near-microscopic soil worm that had been identified by Brenner as an ideal organism on which to study programmed cell death. (britannica.com)
  • In 1974, he began research into the molecular and developmental biology of C. elegans , which has since been extensively used as a model organism . (wikipedia.org)
  • Caenorhabditis elegans is a microscopic, soil-dwelling roundworm that has been powerfully used as a model organism since the early 1970's. (jove.com)
  • This video provides an overview of basic C. elegans biology , a timeline of the many milestones in its short but storied history, and finally a few exciting applications using C. elegans as a model organism. (jove.com)
  • One such model organism is the nematode worm, Caenorhabditis elegans . (mdpi.com)
  • C. elegans has been used as a model organism in scientific research since 1963. (ravelry.com)
  • First, lets get to know C. elegans as a model organism. (jove.com)
  • Now that we have reviewed C. elegans basics, lets learn what makes them a powerful model organism. (jove.com)
  • Recent studies suggest that interactions between C. elegans and its microbial environment may influence the aging and longevity of this simple host organism. (mit.edu)
  • Thus, the small size of this organism pre-adapts C. elegans to living in soil environments that commonly become hypoxic. (biologists.org)
  • The model organism of our studies was a tiny soil worm named C. elegans, which, despite a small nervous system, performs complex behaviors. (europa.eu)
  • To expand the understanding of aging in the model organism Caenorhabditis elegans, global quantification of metabolite and protein levels in young and aged nematodes was performed using mass spectrometry. (ovid.com)
  • The nematode Caenorhabditis elegans has been a powerful experimental organism for almost half a century. (asm.org)
  • IMPORTANCE Orsay virus is the only known virus capable of naturally infecting the model organism Caenorhabditis elegans , which shares many evolutionarily conserved genes with humans. (asm.org)
  • The recent discovery of Orsay virus, the first natural viral pathogen of C. elegans , has provided a unique opportunity to exploit this classic model organism to identify host factors critical for virus infection ( 2 , 3 ). (asm.org)
  • To define the proteome of a live animal with tissue and subcellular resolution, we adapted a localized proteomics technology for use in the multicellular model organism Caenorhabditis elegans . (sciencemag.org)
  • This chapter considers the use of the model organism and key beneficial soil nematode, Caenorhabditis elegans, as an effective strategy for examining fungicide effects on growth, reproduction, nervous system and behavior. (intechopen.com)
  • Here we test the co-adaptation hypothesis by studying an organism (Caenorhabditis elegans) in which both fitness and thermal preference can be reliably measured. (diva-portal.org)
  • Genetic analysis in the small nematode worm Caenorhabditis elegans has elucidated the mechanisms of many basic biological processes. (els.net)
  • The nematode (worm) C. elegans is one of the widely studied animal model organisms in biology. (rsc.org)
  • have now obtained clues to this process from a surprising source, namely a soil-dwelling nematode worm called Caenorhabiditis elegans . (elifesciences.org)
  • O'Connell, K. F., Leys, C. M. & White, J. G. A genetic screen for temperature-sensitive cell-division mutants of Caenorhabditis elegans . (nature.com)
  • Also, the C. elegans genetic center, or CGC, maintains a large repository of mutants, which are available to researchers for a small fee. (jove.com)
  • For their identification, we established a Caenorhabditis elegans AC model and tested mutants in which signaling pathways pertinent to acclimatory responses are mutated. (biomedsearch.com)
  • C. elegans mutants with severe motility defects acquire almost no biofilm, indicating that normal animals accumulate the biofilm matrix as they move through a Yersinia lawn. (asm.org)
  • Here, we characterize mutants that lack μ2 adaptin, encoded by the apm-2 gene (also called dpy-23 ), in the nematode Caenorhabditis elegans . (rupress.org)
  • Moreover, the decrease in synaptic vesicle number does not cause a locomotion defect in μ2 knockout mutants, so a smaller reserve pool might be adequate for C. elegans under normal condition. (rupress.org)
  • The dauer arrest phenotype of eak-3 mutants is fully suppressed by mutations in daf-16/FoxO, which encodes the major target of C. elegans insulin-like signaling, and daf-12, which encodes a nuclear receptor regulated by steroid hormones known as dafachronic acids. (unboundmedicine.com)
  • Sundaram M and Han M (1996) Control and integration of cell signaling pathways during C. elegans vulval development. (els.net)
  • In this review, toxicogenomic studies performed in C. elegans exposed to various metals will be discussed, highlighting how this non-mammalian system can be utilized to study cellular processes and pathways induced by metals. (frontiersin.org)
  • Using RNA interference to inhibit the function of immune signaling pathways in C. elegans , we found that different immune response pathways regulate expression of distinct but overlapping sets of antimicrobial genes. (asm.org)
  • The unique patterns of antimicrobial gene expression observed when C. elegans is exposed to different pathogens or when different immune signaling pathways are perturbed suggest that a large set of yet to be identified pathogen recognition receptors (PRRs) exist in the nematode. (asm.org)
  • We also propose the existence of an "antimicrobial fingerprint," which will aid in assigning newly identified C. elegans innate immunity genes to known immune signaling pathways. (asm.org)
  • The genetics of Caenorhabditis elegans. (nih.gov)
  • de Bono M and Bargmann CI (1998) Natural variation in a neuropeptide Y receptor homolog modifies social behaviour and food response in C. elegans. (els.net)
  • Apoptosis due to synaptic failure also requires the C. elegans homolog of PCH2 , a budding yeast pachytene checkpoint gene, which suggests that this surveillance mechanism is widely conserved. (sciencemag.org)
  • A PDK1 homolog is necessary and sufficient to transduce AGE-1 PI3 kinase signals that regulate diapause in Caenorhabditis elegans. (wikipathways.org)
  • The C. elegans PTEN homolog, DAF-18, acts in the insulin receptor-like metabolic signaling pathway. (wikipathways.org)
  • humans led to the nematode Caenorhabditis elegans , a near-microscopic soil worm that begins life with just 1,090 cells. (britannica.com)
  • In C. elegans , however, neither steps nor impulses have been achieved under normal assay conditions in which the worm is crawling on an agar surface. (jneurosci.org)
  • Since then, with the help of a growing number of investigators, knowledge about the biology of "the worm" has accumulated at a steadily accelerating pace to the extent that C. elegans is now probably the most completely understood metazoan in terms of anatomy, genetics, development, and behavior. (cshlpress.com)
  • This "Book of the Worm" serves as a reference source for C. elegans investigators as well as an introductory monograph for other biologists. (cshlpress.com)
  • Caenorhabditis elegans is a transparent worm about 1 mm in length that lives in soil. (ravelry.com)
  • Here we report the molecular identification and expression of a Na/HCO3 cotransporter from the round worm, Caeno-rhabditis elegans (ceNBC). (mcmaster.ca)
  • who was investigating the nematode Caenorhabditis elegans . (britannica.com)
  • Transgenerational Effects of Early Life Starvation on Growth, Reproduction, and Stress Resistance in Caenorhabditis elegans. (sigmaaldrich.com)
  • C. elegans are multicellular organisms that are approximately 1 mm long. (jove.com)
  • Early studies on C . elegans began in 1962 with some works on cell lineage and apoptosis [ 1 , 2 ]. (hindawi.com)
  • Sulston JE, Schierenberg E, White JG and Thomson JN (1983) The embryonic cell lineage of the nematode C. elegans. (els.net)
  • In 1976, John Sulston, who worked with Brenner, published a complete cell lineage of C. elegans. (jove.com)
  • Caenorhabditis elegans is a free-living, transparent nematode (roundworm), about 1 mm in length, which lives in temperate soil environments. (news-medical.net)
  • The microscopic roundworm Caenorhabditis elegans, or C. elegans, is known to spend up to 20 minutes seeking out snacks in its immediate surroundings before endeavoring to look elsewhere. (news-medical.net)
  • The nematode (roundworm) Caenorhabditis elegans lives in soil and eats bacteria. (tdl.org)
  • This study examined the effects of oxygen tensions ranging from 0 to 90 kPa on the metabolic rate (rate of carbon dioxide production), movement and survivorship of the free-living soil nematode Caenorhabditis elegans. (biologists.org)
  • Functional genomic analysis of cell division in C. elegans using RNAi of genes on chromosome III. (nature.com)
  • 2002) Loss of the putative RNA-directed RNA polymerase RRF-3 makes C. elegans hypersensitive to RNAi. (springer.com)
  • A targeted RNA interference (RNAi) knockdown screen further identified the C. elegans gene nck-1 , which has a human ortholog that interacts with TNK2 and WASP, as required for Orsay virus infection. (asm.org)
  • While Caenorhabditis elegans has played a critical role in the discoveries of evolutionarily conserved processes such as RNA interference (RNAi) ( 1 ), its use in the study of host-virus interactions has been limited by a lack of viruses capable of infecting C. elegans . (asm.org)
  • By the year 2000, RNA interference (RNAi) technology had emerged as a fast, simple, and inexpensive technique for targeted gene knockdown, and was routinely being used to study in vivo gene function in C. elegans. (wikipedia.org)
  • More recently, these investigations have uncovered details of the natural pathogens of C. elegans , including the description of a novel intracellular microsporidian parasite as well as new nodaviruses, the first identification of viral infections of this nematode. (asm.org)
  • The nucleotide sequences complexity in chromosome 3 of Caenorhabditis elegans ( C. elegans ) is studied. (hindawi.com)
  • The C . elegans has 5 chromosomes autosomes plus the sex chromosome X. Totally, it is made up of nearly 100 million base pairs and 19000 genes [ 3 - 5 ]. (hindawi.com)
  • Study on fractal analysis of multigenome of C . elegans has shown that chromosome 3 is the one with multifractal characteristics higher than the others, the less multifractal appears to be the chromosome sexual X [ 6 ]. (hindawi.com)
  • Thus, chromosome 3 of C . elegans has been carefully studied because its unsymmetrical and inhomogeneous statistical characteristics. (hindawi.com)
  • On the chromosome 3 of C . elegans, 2780 genes have been identified. (hindawi.com)
  • In this paper, almost all nucleotide sequences that are located on chromosome 3 of C . elegans were analyzed and compared with random sequences. (hindawi.com)
  • This culling mechanism is specifically activated by unsynapsed pairing centers, cis -acting chromosome sites that are also required to promote synapsis in Caenorhabditis elegans . (sciencemag.org)
  • We studied interactions of hecd-1 with lin-12 in the somatic gonad and with the other C. elegans Notch gene, glp-1 , in the germ line. (g3journal.org)
  • The C. elegans somatic gonad has a single anchor cell (AC), which induces and organizes the vulva. (g3journal.org)
  • Moreover, research using Caenorhabditis elegans to explore the effects of calcium dysregulation due to presenilin mutations on mitochondrial function, oxidative stress and neurodegeneration is explored. (mdpi.com)
  • Meanwhile, CA was absorbed by the worms and promoted the healthspan of C. elegans by improving the mobility, reducing the accumulation of age pigment, delaying Aβ-induced and polyQ-dependent paralysis and increasing the resistance to heat and oxidative stress. (rsc.org)
  • Asymmetric arginine dimethylation determines life span in C. elegans by regulating forkhead transcription factor DAF-16. (wikipathways.org)
  • Studies in invertebrates, particularly Caenorhabditis elegans, have uncovered numerous genes involved in aging, many conserved in mammals. (caltech.edu)
  • Many of the host genes involved in pathogen defense in mammals also function in host defense of C. elegans ( 3 , 10 , 35 , 46 ). (asm.org)
  • The nematode Caenorhabditis elegans is a genetically tractable alternative for investigating the pathogenic bacterium Pseudomonas aeruginosa . (pnas.org)
  • Pseudomonas aeruginosa, a Gram-negative bacterium, is a pathogen of a diverse variety of hosts including mammals and the nematode Caenorhabditis elegans. (harvard.edu)
  • Furthermore, protection from P. aeruginosa was similarly induced by a P. aeruginosa gacA mutant with attenuated virulence but not by a different C. elegans -associated Pseudomonas sp. (asm.org)
  • The nematode C. elegans is susceptible to many of the pathogens that infect humans, including gram-positive Staphylococcus aureus and gram-negative Serratia marcescens and Pseudomonas aeruginosa ( 28 , 31 , 45 , 49 , 52 ). (asm.org)
  • C. elegans navigates to favorable conditions by chemotaxis, thermotaxis, and aerotaxis. (pnas.org)
  • The sensorimotor transformation underlying Caenorhabditis elegans chemotaxis has been difficult to measure directly under normal assay conditions. (jneurosci.org)
  • We found that the step responses likely to underlie C. elegans chemotaxis in steep gradients are complex, with multiple phases and a nonlinear dependence on the sign and amplitude of the stimulus. (jneurosci.org)
  • The characterization of genes responsible for programmed cell death in C. elegans has defined a molecular genetic pathway. (aacrjournals.org)
  • The complementary use of proteomics and metabolomics yielded unique insights into the molecular processes altered with age in C. elegans. (ovid.com)
  • C. elegans has been thoroughly studied by geneticists , developmental biologists and neurologists . (everything2.com)
  • Several developmental stages of C. elegans were able to withstand up to 24 h of anoxia without major mortality. (biologists.org)
  • In C. elegans embryos, the combined Wnt/MAPK pathway polarizes the founder cell of mesendoderm, EMS blastomere, such that EMS produces two daughters with distinct developmental fates. (tdl.org)
  • Loss-of-function mutations in C. elegans egl-9 , a gene required for normal egg laying, confer strong resistance to the paralysis. (pnas.org)
  • In this study, we used Caenorhabditis elegans to investigate such mechanisms. (asm.org)
  • As the yeast ortholog of HECD-1 , Ufd4p, has been shown to function in quality control, and C. elegans HECD-1 has been shown to affect mitochondrial maintenance, we propose that the different genetic interactions between hecd-1 and Notch genes we observed in different cell contexts may reflect differences in quality control regulatory mechanisms or in cellular metabolism. (g3journal.org)
  • Finally, and most important, many cell biological processes identified in C. elegans have been found to be conserved evolutionarily. (jneurosci.org)
  • Thus, genetic screening in C. elegans identified critical roles in virus infection for evolutionarily conserved genes in a known human pathway. (asm.org)
  • The ability to generate transgenic animals to study gene expression and function is a powerful and important part of the Caenorhabditis elegans genetic toolbox. (rug.nl)
  • Research performed in C. elegans has led to insights in apoptosis, gene expression, and neurodegeneration, all of which can be altered by metal exposure. (frontiersin.org)
  • Background: Physiologically based modelling using DEBtox (dynamic energy budget in toxicology) and transcriptional profiling were used in Caenorhabditis elegans to identify how physiological modes of action, as indicated by effects on system level resource allocation were associated with changes in gene expression following exposure to three toxic chemicals: cadmium, fluoranthene (FA) and atrazine (AZ). (uva.nl)
  • We show that the nematode Caenorhabditis elegans orients to the earth's magnetic field during vertical burrowing migrations. (elifesciences.org)
  • Gandre S., van der Bliek A.M. (2007) Mitochondrial Division in Caenorhabditis elegans . (springer.com)
  • We describe experiments with two types of immunologic probes, rabbit sera and mouse monoclonal antibodies, directed against cytoplasmic granules that are unique to germ-line cells in the nematode, Caenorhabditis elegans , and that may correspond to the germ-line-specific structures seen by electron microscopy in C. elegans embryos. (springer.com)
  • With the extensive development of serial-section electron microscopy of Caenorhabditis elegans , and experimental studies of its development, it has been possible to analyse in more detail the structure of the buccal capsule and its formation during moulting. (wormatlas.org)
  • Another reason C. elegans is so easy to study is that it has a transparent body and each of its cells can be examined individually under a microscope without dissecting it. (everything2.com)
  • Princeton University researchers have discovered that learned behaviors can be inherited for multiple generations in C. elegans, transmitted from parent to progeny via eggs and sperm cells. (news-medical.net)
  • The C.elegans cells are diploid. (citizendium.org)
  • A specific set of cells is eliminated by cell extrusion by caspase-deficient C. elegans embryos. (mit.edu)
  • The ability to withstand low ambient oxygen levels appears to be a consequence of the small body size of C. elegans, which allows diffusion to supply oxygen readily to the cells without requiring any specialized respiratory or metabolic adaptations. (biologists.org)
  • The Caenorhabditis elegans germline is composed of mitotically dividing cells at the distal end that give rise to meiotic cells more proximally. (biologists.org)
  • 1991 ) Two C. elegans genes control the programmed deaths of specific cells in the pharynx. (biologists.org)
  • Orsay virus infects primarily C. elegans intestinal cells ( 5 ) and leads to morphological disruptions of the intestine ( 3 ). (asm.org)
  • Chemical reprogramming of Caenorhabditis elegans germ cell fate. (biomedsearch.com)
  • 1990 ) fog-1 , a regulatory gene required for specification of spermatogenesis in the germ line of Caenorhabditis elegans . (biologists.org)
  • 1992 ) Characterization of a germ-line proliferation mutation in C. elegans . (biologists.org)
  • 1997 ) Germ-line tumor formation caused by activation of glp-1 , a Caenorhabditis elegans member of the Notch family of receptors. (biologists.org)
  • 1994 ) GLP-1 is localized to the mitotic region of the C. elegans germ line. (biologists.org)
  • Using the lectin wheat germ agglutinin as a probe, we show that the matrix on C. elegans contains carbohydrate produced by Yersinia . (asm.org)
  • In the present study, we first show that the lectin wheat germ agglutinin (WGA) is a strong probe for biofilm detection on C. elegans . (asm.org)

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