Caenorhabditis elegans
Caenorhabditis elegans Proteins
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.
Caenorhabditis
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.
Vulva
Animals, Genetically Modified
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
RNA, Helminth
Disorders of Sex Development
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.
Mutation
Molecular Sequence Data
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.
Amino Acid Sequence
RNA Interference
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.
Sequence Homology, Amino Acid
Phenotype
Nematoda
Embryo, Nonmammalian
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
Larva
Gene Expression Regulation, Developmental
Base Sequence
Green Fluorescent Proteins
Cloning, Molecular
Pharynx
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).
Sequence Alignment
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.
Transcription Factors
Signal Transduction
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.
Oviposition
Conserved Sequence
Locomotion
Genes, Lethal
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.
Alleles
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
Membrane Proteins
Chromosome Mapping
Antinematodal Agents
GATA Transcription Factors
A family of transcription factors that contain two ZINC FINGER MOTIFS and bind to the DNA sequence (A/T)GATA(A/G).
Hermaphroditic Organisms
Animals and plants which have, as their normal mode of reproduction, both male and female sex organs in the same individual.
Meiosis
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.
Models, Biological
Luminescent Proteins
Gene Expression Regulation
Molting
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 Fusion Proteins
DNA, Complementary
Sex Determination Processes
The mechanisms by which the SEX of an individual's GONADS are fixed.
Levamisole
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)
Morphogenesis
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.
Neurons
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.
Pharyngeal Muscles
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.
Nervous System
Protein Structure, Tertiary
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.
Evolution, Molecular
Genome
Suppression, Genetic
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).
Models, Genetic
Intestines
Subcutaneous Tissue
Sex Determination Analysis
Validation of the SEX of an individual by inspection of the GONADS and/or by genetic tests.
Cell Lineage
Body Patterning
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.
Trans-Splicing
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, Fluorescence
Species Specificity
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, Double-Stranded
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.
DNA Primers
Cell Polarity
Genes, Reporter
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.
Muscle, Striated
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.
Nerve Tissue Proteins
'Nerve tissue proteins' are specialized proteins found within the nervous system's biological tissue, including neurofilaments, neuronal cytoskeletal proteins, and neural cell adhesion molecules, which facilitate structural support, intracellular communication, and synaptic connectivity essential for proper neurological function.
Protein Binding
Temperature
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, Messenger
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.
Carrier Proteins
Genetic Complementation Test
Multigene Family
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)
DNA-Binding Proteins
Haemonchus
Drosophila melanogaster
A species of fruit fly much used in genetics because of the large size of its chromosomes.
Receptors, Notch
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.
Gene Deletion
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.
Chromosomes
Sensory Receptor Cells
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.
Sequence Analysis, DNA
Mutagenesis
Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.
Blastomeres
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.
Ethyl Methanesulfonate
X Chromosome
Fertility
RNA-Binding Proteins
Two-Hybrid System Techniques
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.
Protein Transport
Oocytes
Aging
Nuclear Proteins
Drosophila Proteins
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.
Oogenesis
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
Transcription, Genetic
Epistasis, Genetic
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, Suppressor
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.
Homeodomain Proteins
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).
Introns
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.
Neuropeptides
Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.
Tail
Cilia
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)
Chromosome Pairing
The alignment of CHROMOSOMES at homologous sequences.
Protein Isoforms
Galectins
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.
Receptor, Insulin
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.
Ascaris suum
Gene Expression
Mosaicism
Cell Cycle Proteins
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.
Cell Nucleus
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)
Spermatogenesis
The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.
Drosophila
Biological Evolution
Spindle Apparatus
Crosses, Genetic
Mitosis
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.