DNA, Satellite: Highly repetitive DNA sequences found in HETEROCHROMATIN, mainly near centromeres. They are composed of simple sequences (very short) (see MINISATELLITE REPEATS) repeated in tandem many times to form large blocks of sequence. Additionally, following the accumulation of mutations, these blocks of repeats have been repeated in tandem themselves. The degree of repetition is on the order of 1000 to 10 million at each locus. Loci are few, usually one or two per chromosome. They were called satellites since in density gradients, they often sediment as distinct, satellite bands separate from the bulk of genomic DNA owing to a distinct BASE COMPOSITION.Satellite Cells, Skeletal Muscle: Elongated, spindle-shaped, quiescent myoblasts lying in close contact with adult skeletal muscle. They are thought to play a role in muscle repair and regeneration.RNA, Satellite: Small, linear single-stranded RNA molecules functionally acting as molecular parasites of certain RNA plant viruses. Satellite RNAs exhibit four characteristic traits: (1) they require helper viruses to replicate; (2) they are unnecessary for the replication of helper viruses; (3) they are encapsidated in the coat protein of the helper virus; (4) they have no extensive sequence homology to the helper virus. Thus they differ from SATELLITE VIRUSES which encode their own coat protein, and from the genomic RNA; (=RNA, VIRAL); of satellite viruses. (From Maramorosch, Viroids and Satellites, 1991, p143)Satellite Communications: Communications using an active or passive satellite to extend the range of radio, television, or other electronic transmission by returning signals to earth from an orbiting satellite.Satellite Viruses: Defective viruses which can multiply only by association with a helper virus which complements the defective gene. Satellite viruses may be associated with certain plant viruses, animal viruses, or bacteriophages. They differ from satellite RNA; (RNA, SATELLITE) in that satellite viruses encode their own coat protein.Satellite Cells, Perineuronal: The non-neuronal cells that surround the neuronal cell bodies of the GANGLIA. They are distinguished from the perineuronal satellite oligodendrocytes (OLIGODENDROGLIA) found in the central nervous system.PAX7 Transcription Factor: A paired box transcription factor that is involved in EMBRYONIC DEVELOPMENT of the CENTRAL NERVOUS SYSTEM and SKELETAL MUSCLE.Satellite Imagery: Composition of images of EARTH or other planets from data collected during SPACE FLIGHT by remote sensing instruments onboard SPACECRAFT. The satellite sensor systems measure and record absorbed, emitted, or reflected energy across the spectra, as well as global position and time.Hospitals, Satellite: Those hospitals which are extensions of a main hospital and are wholly or partly administered by that hospital.Spacecraft: Devices, manned and unmanned, which are designed to be placed into an orbit about the Earth or into a trajectory to another celestial body. (NASA Thesaurus, 1988)Cucumber Mosaic Virus Satellite: A satellite RNA (not a satellite virus) which has several types. Different cucumoviruses can act as helper viruses for different types.Muscle Development: Developmental events leading to the formation of adult muscular system, which includes differentiation of the various types of muscle cell precursors, migration of myoblasts, activation of myogenesis and development of muscle anchorage.Regeneration: The physiological renewal, repair, or replacement of tissue.MyoD Protein: A myogenic regulatory factor that controls myogenesis. Though it is not clear how its function differs from the other myogenic regulatory factors, MyoD appears to be related to fusion and terminal differentiation of the muscle cell.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.Centromere: The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.Tobacco mosaic satellite virus: A spherical RNA satellite virus which requires an obligatory helper TOBACCO MOSAIC VIRUS for replication.Muscle Fibers, Skeletal: Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.Remote Sensing Technology: Observation and acquisition of physical data from a distance by viewing and making measurements from a distance or receiving transmitted data from observations made at distant location.Myoblasts: Embryonic (precursor) cells of the myogenic lineage that develop from the MESODERM. They undergo proliferation, migrate to their various sites, and then differentiate into the appropriate form of myocytes (MYOCYTES, SKELETAL; MYOCYTES, CARDIAC; MYOCYTES, SMOOTH MUSCLE).Abelmoschus: A plant genus of the family MALVACEAE, order Malvales, subclass Dilleniidae best known for okra.Tobacco necrosis satellite virus: An icosahedral RNA satellite virus which requires an obligatory Tobacco necrosis virus (see NECROVIRUS) for its replication.Myogenic Regulatory Factor 5: A SKELETAL MUSCLE-specific transcription factor that contains a basic HELIX-LOOP-HELIX MOTIF. It plays an essential role in MUSCLE DEVELOPMENT.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Plant Viruses: Viruses parasitic on plants higher than bacteria.Heterochromatin: The portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.Myogenin: A myogenic regulatory factor that controls myogenesis. Myogenin is induced during differentiation of every skeletal muscle cell line that has been investigated, in contrast to the other myogenic regulatory factors that only appear in certain cell types.delta-Globins: A member of the beta-globin family. In humans, delta-globin is encoded in the beta-globin gene cluster located on CHROMOSOME 11. Two delta-globin chains along with two alpha-globin chains form HEMOGLOBIN A2 which makes up about 3% of the HEMOGLOBIN in adults.Cardiotoxins: Agents that have a damaging effect on the HEART. Such damage can occur from ALKYLATING AGENTS; FREE RADICALS; or metabolites from OXIDATIVE STRESS and in some cases is countered by CARDIOTONIC AGENTS. Induction of LONG QT SYNDROME or TORSADES DE POINTES has been the reason for viewing some drugs as cardiotoxins.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.Panicum: A plant genus of the family POACEAE. The seed is one of the EDIBLE GRAINS used in millet cereals and in feed for birds and livestock (ANIMAL FEED). It contains diosgenin (SAPONINS).Mosaic Viruses: Viruses which produce a mottled appearance of the leaves of plants.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Repetitive Sequences, Nucleic Acid: Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).Begomovirus: A genus of plant viruses in the family GEMINIVIRIDAE that are transmitted in nature by whitefly Bemisia tabaci.Myostatin: A growth differentiation factor that is a potent inhibitor of SKELETAL MUSCLE growth. It may play a role in the regulation of MYOGENESIS and in muscle maintenance during adulthood.Cucumovirus: A genus of plant viruses of the family BROMOVIRIDAE, which infect cucurbits and solanaceous plants. Transmission occurs via aphids in a non-persistent manner, and also via seeds. The type species Cucumber mosaic virus, a CUCUMOVIRUS, should not be confused with Cucumber green mottle mosaic virus, a TOBAMOVIRUS.Animal Migration: Periodic movements of animals in response to seasonal changes or reproductive instinct. Hormonal changes are the trigger in at least some animals. Most migrations are made for reasons of climatic change, feeding, or breeding.Geographic Information Systems: Computer systems capable of assembling, storing, manipulating, and displaying geographically referenced information, i.e. data identified according to their locations.Nepovirus: A genus of polyhedral plant viruses of the family COMOVIRIDAE causing ringspots and spotting on leaves or sometimes symptomless infection. Transmission occurs by seeds, soil nematodes, or experimentally by mechanical inoculation. Tobacco ringspot virus is the type species.In Situ Hybridization, Fluorescence: A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.Mice, Inbred mdx: A strain of mice arising from a spontaneous MUTATION (mdx) in inbred C57BL mice. This mutation is X chromosome-linked and produces viable homozygous animals that lack the muscle protein DYSTROPHIN, have high serum levels of muscle ENZYMES, and possess histological lesions similar to human MUSCULAR DYSTROPHY. The histological features, linkage, and map position of mdx make these mice a worthy animal model of DUCHENNE MUSCULAR DYSTROPHY.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.DNA Restriction Enzymes: Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.Muscular Atrophy: Derangement in size and number of muscle fibers occurring with aging, reduction in blood supply, or following immobilization, prolonged weightlessness, malnutrition, and particularly in denervation.Centromere Protein B: A DNA-binding protein that interacts with a 17-base pair sequence known as the CENP-B box motif. The protein is localized constitutively to the CENTROMERE and plays an important role in its maintenance.Plant Diseases: Diseases of plants.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Cobra Cardiotoxin Proteins: Most abundant proteins in COBRA venom; basic polypeptides of 57 to 62 amino acids with four disulfide bonds and a molecular weight of less than 7000; causes skeletal and cardiac muscle contraction, interferes with neuromuscular and ganglionic transmission, depolarizes nerve, muscle and blood cell membranes, thus causing hemolysis.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Myoblasts, Skeletal: Precursor cells destined to differentiate into skeletal myocytes (MYOCYTES, SKELETAL).Carmovirus: A genus in the family TOMBUSVIRIDAE mostly found in temperate regions. Some species infecting legumes (FABACEAE) are reported from tropical areas. Most viruses are soil-borne, but some are transmitted by the fungus Olpidium radicale and others by beetles. Carnation mottle virus is the type species.Nucleic Acid Hybridization: Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)Extraterrestrial Environment: The environment outside the earth or its atmosphere. The environment may refer to a closed cabin (such as a space shuttle or space station) or to space itself, the moon, or other planets.Hypertrophy: General increase in bulk of a part or organ due to CELL ENLARGEMENT and accumulation of FLUIDS AND SECRETIONS, not due to tumor formation, nor to an increase in the number of cells (HYPERPLASIA).Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Jupiter: The fifth planet in order from the sun. It is one of the five outer planets of the solar system. Its sixteen natural satellites include Callisto, Europa, Ganymede, and Io.Myogenic Regulatory Factors: A family of muscle-specific transcription factors which bind to DNA in control regions and thus regulate myogenesis. All members of this family contain a conserved helix-loop-helix motif which is homologous to the myc family proteins. These factors are only found in skeletal muscle. Members include the myoD protein (MYOD PROTEIN); MYOGENIN; myf-5, and myf-6 (also called MRF4 or herculin).Stem Cells: Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.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.Earth (Planet): Planet that is the third in order from the sun. It is one of the four inner or terrestrial planets of the SOLAR SYSTEM.Pluto: The ninth planet in order from the sun. It is one of the five outer planets of the solar system. Its only natural satellite is Charon.Telemetry: Transmission of the readings of instruments to a remote location by means of wires, radio waves, or other means. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Muscular Diseases: Acquired, familial, and congenital disorders of SKELETAL MUSCLE and SMOOTH MUSCLE.Ageratum: A plant genus of the family ASTERACEAE that contains PYRROLIZIDINE ALKALOIDS. Yellow vein disease of Ageratum is caused by a viral DNA complex of a begomovirus (GEMINIVIRIDAE).Nucleic Acid Renaturation: The reformation of all, or part of, the native conformation of a nucleic acid molecule after the molecule has undergone denaturation.Plants, Toxic: Plants or plant parts which are harmful to man or other animals.Centrioles: Self-replicating, short, fibrous, rod-shaped organelles. Each centriole is a short cylinder containing nine pairs of peripheral microtubules, arranged so as to form the wall of the cylinder.RNA: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Potexvirus: A genus of plant viruses in the family FLEXIVIRIDAE, that cause mosaic and ringspot symptoms. Transmission occurs mechanically. Potato virus X is the type species.Cloning, Molecular: 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.Sasa: A plant genus of the family POACEAE. Folin is the water-soluble extract from Sasa albomarginata. Sasa kurinensis is an ingredient of Sho-ju-sen, a Japanese herbal medicine.Histology, Comparative: The study of the similarities and differences in the structures of homologous tissues across various species.Muscular Dystrophies: A heterogeneous group of inherited MYOPATHIES, characterized by wasting and weakness of the SKELETAL MUSCLE. They are categorized by the sites of MUSCLE WEAKNESS; AGE OF ONSET; and INHERITANCE PATTERNS.Notophthalmus viridescens: A species of newt in the Salamandridae family in which the larvae transform into terrestrial eft stage and later into an aquatic adult. They occur from Canada to southern United States. Viridescens refers to the greenish color often found in this species.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Geminiviridae: A family of plant viruses where the VIRION possesses an unusual morphology consisting of a pair of isometric particles. Transmission occurs via leafhoppers or whitefly. Some viruses cause economically important diseases in cultivated plants. There are four genera: Mastrevirus, Curtovirus, Topocuvirus, and BEGOMOVIRUS.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Chromosomes: 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)Muscles: Contractile tissue that produces movement in animals.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Muscle Denervation: The resection or removal of the innervation of a muscle or muscle tissue.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Geography: The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)Muscular Dystrophy, AnimalViroids: A group of pathogens comprising the smallest known agents of infectious disease. They are unencapsulated and are capable of replicating autonomously in susceptible cells. Positively identified viroids composed of single-stranded RNA have been isolated from higher plants, but the existence of DNA viroids pathogenic to animals is suspected.Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Environmental Monitoring: The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.Mice, Inbred C57BLDNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Cell Lineage: The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.Bacteriophage P2: A species of temperate bacteriophage in the genus P2-like viruses, family MYOVIRIDAE, which infects E. coli. It consists of linear double-stranded DNA with 19-base sticky ends.Syndecan-3: A syndecan found at high levels in the developing LIMB BUDS. It may play a role in the regulation of MUSCULOSKELETAL DEVELOPMENT by modulating the effects of INTERCELLULAR SIGNALING PEPTIDES AND PROTEINS.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.Ecosystem: A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)Muscle Fibers, Fast-Twitch: Skeletal muscle fibers characterized by their expression of the Type II MYOSIN HEAVY CHAIN isoforms which have high ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment. Several fast types have been identified.Base Composition: The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.Trees: Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.Nucleic Acid Denaturation: Disruption of the secondary structure of nucleic acids by heat, extreme pH or chemical treatment. Double strand DNA is "melted" by dissociation of the non-covalent hydrogen bonds and hydrophobic interactions. Denatured DNA appears to be a single-stranded flexible structure. The effects of denaturation on RNA are similar though less pronounced and largely reversible.Paired Box Transcription Factors: A family of transcription factors that control EMBRYONIC DEVELOPMENT within a variety of cell lineages. They are characterized by a highly conserved paired DNA-binding domain that was first identified in DROSOPHILA segmentation genes.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Geographic Mapping: Creating a representation of areas of the earth or other celestial bodies, for the purpose of visualizing spatial distributions of various information.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Climate: The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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)Chromosome Banding: Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. Applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping.Tandem Repeat Sequences: Copies of DNA sequences which lie adjacent to each other in the same orientation (direct tandem repeats) or in the opposite direction to each other (INVERTED TANDEM REPEATS).Hindlimb Suspension: Technique for limiting use, activity, or movement by immobilizing or restraining animal by suspending from hindlimbs or tails. This immobilization is used to simulate some effects of reduced gravity and study weightlessness physiology.Muscle Proteins: The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.Tombusviridae: A family of RNA plant viruses infecting dicotyledons. Transmission is mainly by mechanical inoculation and through propagative plant material. All species elicit formation of multivesicular inclusion bodies. There are at least eight genera: Aureusvirus, Avenavirus, CARMOVIRUS, Dianthovirus, Machlomovirus, Necrovirus, Panicovirus, and TOMBUSVIRUS.Chromosomes, Human, 21-22 and Y: The short, acrocentric human chromosomes, called group G in the human chromosome classification. This group consists of chromosome pairs 21 and 22 and the Y chromosome.Chromosomes, Human, 13-15: The medium-sized, acrocentric human chromosomes, called group D in the human chromosome classification. This group consists of chromosome pairs 13, 14, and 15.Atlantic OceanRain: Water particles that fall from the ATMOSPHERE.Harmful Algal Bloom: An algal bloom where the algae produce powerful toxins that can kill fish, birds, and mammals, and ultimately cause illness in humans. The harmful bloom can also cause oxygen depletion in the water due to the death and decomposition of non-toxic algae species.Meteorology: The science of studying the characteristics of the atmosphere such as its temperature, density, winds, clouds, precipitation, and other atmospheric phenomena and aiming to account for the weather in terms of external influences and the basic laws of physics. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Desmin: An intermediate filament protein found predominantly in smooth, skeletal, and cardiac muscle cells. Localized at the Z line. MW 50,000 to 55,000 is species dependent.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Muscle Cells: Mature contractile cells, commonly known as myocytes, that form one of three kinds of muscle. The three types of muscle cells are skeletal (MUSCLE FIBERS, SKELETAL), cardiac (MYOCYTES, CARDIAC), and smooth (MYOCYTES, SMOOTH MUSCLE). They are derived from embryonic (precursor) muscle cells called MYOBLASTS.Centrifugation, Density Gradient: Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Trigeminal Ganglion: The semilunar-shaped ganglion containing the cells of origin of most of the sensory fibers of the trigeminal nerve. It is situated within the dural cleft on the cerebral surface of the petrous portion of the temporal bone and gives off the ophthalmic, maxillary, and part of the mandibular nerves.Hepatocyte Growth Factor: Multifunctional growth factor which regulates both cell growth and cell motility. It exerts a strong mitogenic effect on hepatocytes and primary epithelial cells. Its receptor is PROTO-ONCOGENE PROTEINS C-MET.Cell Count: The number of CELLS of a specific kind, usually measured per unit volume or area of sample.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Lycopersicon esculentum: A plant species of the family SOLANACEAE, native of South America, widely cultivated for their edible, fleshy, usually red fruit.Pectoralis Muscles: The pectoralis major and pectoralis minor muscles that make up the upper and fore part of the chest in front of the AXILLA.Aging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.Ganglia, Spinal: Sensory ganglia located on the dorsal spinal roots within the vertebral column. The spinal ganglion cells are pseudounipolar. The single primary branch bifurcates sending a peripheral process to carry sensory information from the periphery and a central branch which relays that information to the spinal cord or brain.AT Rich Sequence: A nucleic acid sequence that contains an above average number of ADENINE and THYMINE bases.Luteovirus: A genus of plant viruses that infects both monocotyledonous and dicotyledonous plants. Its organisms are persistently transmitted by aphids, and weeds may provide reservoirs of infection.Chromatin: The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.Telecommunications: Transmission of information over distances via electronic means.Chromosomal Proteins, Non-Histone: Nucleoproteins, which in contrast to HISTONES, are acid insoluble. They are involved in chromosomal functions; e.g. they bind selectively to DNA, stimulate transcription resulting in tissue-specific RNA synthesis and undergo specific changes in response to various hormones or phytomitogens.Chromosomes, Human: Very long DNA molecules and associated proteins, HISTONES, and non-histone chromosomal proteins (CHROMOSOMAL PROTEINS, NON-HISTONE). Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. They carry the hereditary information of the individual.Myosin Heavy Chains: The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. The heavy chains possess actin-binding and ATPase activity.Syndecan-4: A ubiquitously expressed syndecan that is found in all stages of embryonic development and in most adult tissues. Syndecan-4 is found localized to focal adhesion sites in fibronectin-adherent cells and may play a role the process of CELL MIGRATION and CELL PROLIFERATION.Ganglia, Sensory: Clusters of neurons in the somatic peripheral nervous system which contain the cell bodies of sensory nerve axons. Sensory ganglia may also have intrinsic interneurons and non-neuronal supporting cells.Cell SeparationMicroscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Bisbenzimidazole: A benzimidazole antifilarial agent; it is fluorescent when it binds to certain nucleotides in DNA, thus providing a tool for the study of DNA replication; it also interferes with mitosis.Chromosomes, Human, 16-18: The short, submetacentric human chromosomes, called group E in the human chromosome classification. This group consists of chromosome pairs 16, 17, and 18.Y Chromosome: The male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans and in some other male-heterogametic species in which the homologue of the X chromosome has been retained.Melilotus: A plant genus of the family FABACEAE.Stem Cell Niche: A particular zone of tissue composed of a specialized microenvironment where stem cells are retained in a undifferentiated, self-renewable state.Muridae: A family of the order Rodentia containing 250 genera including the two genera Mus (MICE) and Rattus (RATS), from which the laboratory inbred strains are developed. The fifteen subfamilies are SIGMODONTINAE (New World mice and rats), CRICETINAE, Spalacinae, Myospalacinae, Lophiomyinae, ARVICOLINAE, Platacanthomyinae, Nesomyinae, Otomyinae, Rhizomyinae, GERBILLINAE, Dendromurinae, Cricetomyinae, MURINAE (Old World mice and rats), and Hydromyinae.Euchromatin: Chromosome regions that are loosely packaged and more accessible to RNA polymerases than HETEROCHROMATIN. These regions also stain differentially in CHROMOSOME BANDING preparations.Chenopodium: A plant genus in the CHENOPODIACEAE family.Pongo pygmaeus: A species of orangutan, family HOMINIDAE, found in the forests on the island of Borneo.Neuroglia: The non-neuronal cells of the nervous system. They not only provide physical support, but also respond to injury, regulate the ionic and chemical composition of the extracellular milieu, participate in the BLOOD-BRAIN BARRIER and BLOOD-RETINAL BARRIER, form the myelin insulation of nervous pathways, guide neuronal migration during development, and exchange metabolites with neurons. Neuroglia have high-affinity transmitter uptake systems, voltage-dependent and transmitter-gated ion channels, and can release transmitters, but their role in signaling (as in many other functions) is unclear.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.Histones: Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.Atmosphere: The gaseous envelope surrounding a planet or similar body. (From Random House Unabridged Dictionary, 2d ed)DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Retroelements: Elements that are transcribed into RNA, reverse-transcribed into DNA and then inserted into a new site in the genome. Long terminal repeats (LTRs) similar to those from retroviruses are contained in retrotransposons and retrovirus-like elements. Retroposons, such as LONG INTERSPERSED NUCLEOTIDE ELEMENTS and SHORT INTERSPERSED NUCLEOTIDE ELEMENTS do not contain LTRs.Meteorological Concepts: The atmospheric properties, characteristics and other atmospheric phenomena especially pertaining to WEATHER or CLIMATE.Cell Nucleus Structures: Structures that are part of or contained in the CELL NUCLEUS.Oculomotor Muscles: The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.Gene Expression Regulation, Developmental: 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.Oceans and Seas: A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic).Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Stars, Celestial: Large bodies consisting of self-luminous gas held together by their own gravity. (From McGraw Hill Dictionary of Scientific and Technical Terms, 6th ed)Cell Line: Established cell cultures that have the potential to propagate indefinitely.Myofibrils: The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .Dystrophin: A muscle protein localized in surface membranes which is the product of the Duchenne/Becker muscular dystrophy gene. Individuals with Duchenne muscular dystrophy usually lack dystrophin completely while those with Becker muscular dystrophy have dystrophin of an altered size. It shares features with other cytoskeletal proteins such as SPECTRIN and alpha-actinin but the precise function of dystrophin is not clear. One possible role might be to preserve the integrity and alignment of the plasma membrane to the myofibrils during muscle contraction and relaxation. MW 400 kDa.Solar Energy: Energy transmitted from the sun in the form of electromagnetic radiation.Agricultural Irrigation: The routing of water to open or closed areas where it is used for agricultural purposes.Deoxyribonuclease EcoRI: One of the Type II site-specific deoxyribonucleases (EC 184.108.40.206). It recognizes and cleaves the sequence G/AATTC at the slash. EcoRI is from E coliRY13. Several isoschizomers have been identified. EC 3.1.21.-.RNA Viruses: Viruses whose genetic material is RNA.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.Primed In Situ Labeling: A technique that labels specific sequences in whole chromosomes by in situ DNA chain elongation or PCR (polymerase chain reaction).Muscular Dystrophy, Duchenne: An X-linked recessive muscle disease caused by an inability to synthesize DYSTROPHIN, which is involved with maintaining the integrity of the sarcolemma. Muscle fibers undergo a process that features degeneration and regeneration. Clinical manifestations include proximal weakness in the first few years of life, pseudohypertrophy, cardiomyopathy (see MYOCARDIAL DISEASES), and an increased incidence of impaired mentation. Becker muscular dystrophy is a closely related condition featuring a later onset of disease (usually adolescence) and a slowly progressive course. (Adams et al., Principles of Neurology, 6th ed, p1415)Dipodomys: A genus of the family Heteromyidae which contains 22 species. Their physiology is adapted for the conservation of water, and they seldom drink water. They are found in arid or desert habitats and travel by hopping on their hind limbs.Arachis hypogaea: A plant species of the family FABACEAE that yields edible seeds, the familiar peanuts, which contain protein, oil and lectins.Lonicera: A plant genus of the family CAPRIFOLIACEAE. Members contain iridoid glucosides.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.RNA, Catalytic: RNA that has catalytic activity. The catalytic RNA sequence folds to form a complex surface that can function as an enzyme in reactions with itself and other molecules. It may function even in the absence of protein. There are numerous examples of RNA species that are acted upon by catalytic RNA, however the scope of this enzyme class is not limited to a particular type of substrate.Beetles: INSECTS of the order Coleoptera, containing over 350,000 species in 150 families. They possess hard bodies and their mouthparts are adapted for chewing.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.X Chromosome: 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.Bromodeoxyuridine: A nucleoside that substitutes for thymidine in DNA and thus acts as an antimetabolite. It causes breaks in chromosomes and has been proposed as an antiviral and antineoplastic agent. It has been given orphan drug status for use in the treatment of primary brain tumors.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.Ice: The solid substance formed by the FREEZING of water.Maps as Topic: Representations, normally to scale and on a flat medium, of a selection of material or abstract features on the surface of the earth, the heavens, or celestial bodies.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Community Health Centers: Facilities which administer the delivery of health care services to people living in a community or neighborhood.Cell Transplantation: Transference of cells within an individual, between individuals of the same species, or between individuals of different species.Neurilemma: The outermost cytoplasmic layer of the SCHWANN CELLS covering NERVE FIBERS.Tropical Climate: A climate which is typical of equatorial and tropical regions, i.e., one with continually high temperatures with considerable precipitation, at least during part of the year. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Animal Identification Systems: Procedures for recognizing individual animals and certain identifiable characteristics pertaining to them; includes computerized methods, ear tags, etc.Pacific OceanMuscle Fibers, Slow-Twitch: Skeletal muscle fibers characterized by their expression of the Type I MYOSIN HEAVY CHAIN isoforms which have low ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment.Gene Expression Regulation: 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.Genetic Variation: Genotypic differences observed among individuals in a population.Proto-Oncogene Proteins c-met: Cell surface protein-tyrosine kinase receptors for HEPATOCYTE GROWTH FACTOR. They consist of an extracellular alpha chain which is disulfide-linked to the transmembrane beta chain. The cytoplasmic portion contains the catalytic domain and sites critical for the regulation of kinase activity. Mutations of the gene for PROTO-ONCOGENE PROTEINS C-MET are associated with papillary renal carcinoma and other neoplasia.Mutation: 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.Oceanography: The science that deals with the ocean and its phenomena. (Webster, 3d ed)Insulin-Like Growth Factor I: A well-characterized basic peptide believed to be secreted by the liver and to circulate in the blood. It has growth-regulating, insulin-like, and mitogenic activities. This growth factor has a major, but not absolute, dependence on GROWTH HORMONE. It is believed to be mainly active in adults in contrast to INSULIN-LIKE GROWTH FACTOR II, which is a major fetal growth factor.Blotting, Southern: A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.