Photoreceptor Cells: Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.Photoreceptor Cells, Vertebrate: Specialized PHOTOTRANSDUCTION neurons in the vertebrates, such as the RETINAL ROD CELLS and the RETINAL CONE CELLS. Non-visual photoreceptor neurons have been reported in the deep brain, the PINEAL GLAND and organs of the circadian system.Photoreceptor Cells, Invertebrate: Specialized cells in the invertebrates that detect and transduce light. They are predominantly rhabdomeric with an array of photosensitive microvilli. Illumination depolarizes invertebrate photoreceptors by stimulating Na+ influx across the plasma membrane.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Retinal Cone Photoreceptor Cells: Photosensitive afferent neurons located primarily within the FOVEA CENTRALIS of the MACULA LUTEA. There are three major types of cone cells (red, blue, and green) whose photopigments have different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Retinal Degeneration: A retrogressive pathological change in the retina, focal or generalized, caused by genetic defects, inflammation, trauma, vascular disease, or aging. Degeneration affecting predominantly the macula lutea of the retina is MACULAR DEGENERATION. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p304)Plant Roots: The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)Retina: The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.Genes, Plant: The functional hereditary units of PLANTS.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Plant Extracts: Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.Rod Opsins: Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.Plant Shoots: New immature growth of a plant including stem, leaves, tips of branches, and SEEDLINGS.Rhodopsin: A purplish-red, light-sensitive pigment found in RETINAL ROD CELLS of most vertebrates. It is a complex consisting of a molecule of ROD OPSIN and a molecule of 11-cis retinal (RETINALDEHYDE). Rhodopsin exhibits peak absorption wavelength at about 500 nm.Eye ProteinsElectroretinography: Recording of electric potentials in the retina after stimulation by light.Retinal Photoreceptor Cell Outer Segment: The light sensitive outer portion of a retinal rod or a cone photoreceptor cell. The outer segment contains a stack of disk membranes laden with photoreceptive pigments (RETINAL PIGMENTS). The outer segment is connected to the inner segment by a PHOTORECEPTOR CONNECTING CILIUM.Plants, Medicinal: Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Plant Development: Processes orchestrated or driven by a plethora of genes, plant hormones, and inherent biological timing mechanisms facilitated by secondary molecules, which result in the systematic transformation of plants and plant parts, from one stage of maturity to another.Rod Cell Outer Segment: The portion of a retinal rod cell situated between the ROD INNER SEGMENT and the RETINAL PIGMENT EPITHELIUM. It contains a stack of photosensitive disk membranes laden with RHODOPSIN.Photoreceptors, Plant: Plant proteins that mediate LIGHT SIGNAL TRANSDUCTION. They are involved in PHOTOTROPISM and other light adaption responses during plant growth and development . They include the phototropins, phytochromes (PHYTOCHROME), and members of the ubiquitous cryptochrome family.Photoreceptor Connecting Cilium: The bridge between the inner and the outer segments of a retinal rod or a cone photoreceptor cell. Through it, proteins synthesized in the inner segment are transported to the outer segment.Plants, Toxic: Plants or plant parts which are harmful to man or other animals.Light Signal Transduction: The conversion of absorbed light energy into molecular signals.Dark Adaptation: Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.Plant Cells: Basic functional unit of plants.Opsins: Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.Vision, Ocular: The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.Plant Stems: Parts of plants that usually grow vertically upwards towards the light and support the leaves, buds, and reproductive structures. (From Concise Dictionary of Biology, 1990)Retinitis Pigmentosa: Hereditary, progressive degeneration of the neuroepithelium of the retina characterized by night blindness and progressive contraction of the visual field.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.Retinal Pigments: Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.Photoreceptors, Microbial: Light absorbing proteins and protein prosthetic groups found in certain microorganisms. Some microbial photoreceptors initiate specific chemical reactions which signal a change in the environment, while others generate energy by pumping specific ions across a cellular membrane.Plants, Edible: An organism of the vegetable kingdom suitable by nature for use as a food, especially by human beings. Not all parts of any given plant are edible but all parts of edible plants have been known to figure as raw or cooked food: leaves, roots, tubers, stems, seeds, buds, fruits, and flowers. The most commonly edible parts of plants are FRUIT, usually sweet, fleshy, and succulent. Most edible plants are commonly cultivated for their nutritional value and are referred to as VEGETABLES.Arabidopsis Proteins: Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.Plant Structures: The parts of plants, including SEEDS.Darkness: The absence of light.Arrestin: A 48-Kd protein of the outer segment of the retinal rods and a component of the phototransduction cascade. Arrestin quenches G-protein activation by binding to phosphorylated photolyzed rhodopsin. Arrestin causes experimental autoimmune uveitis when injected into laboratory animals.Cyclic Nucleotide Phosphodiesterases, Type 6: A cyclic nucleotide phosphodiesterase subfamily that is highly specific for CYCLIC GMP. It is found predominantly in the outer segment PHOTORECEPTOR CELLS of the RETINA. It is comprised of two catalytic subunits, referred to as alpha and beta, that form a dimer. In addition two regulatory subunits, referred to as gamma and delta, modulate the activity and localization of the enzyme.Transducin: A heterotrimeric GTP-binding protein that mediates the light activation signal from photolyzed rhodopsin to cyclic GMP phosphodiesterase and is pivotal in the visual excitation process. Activation of rhodopsin on the outer membrane of rod and cone cells causes GTP to bind to transducin followed by dissociation of the alpha subunit-GTP complex from the beta/gamma subunits of transducin. The alpha subunit-GTP complex activates the cyclic GMP phosphodiesterase which catalyzes the hydrolysis of cyclic GMP to 5'-GMP. This leads to closure of the sodium and calcium channels and therefore hyperpolarization of the rod cells. EC 3.6.1.-.Adaptation, Ocular: The adjustment of the eye to variations in the intensity of light. Light adaptation is the adjustment of the eye when the light threshold is increased; DARK ADAPTATION when the light is greatly reduced. (From Cline et al., Dictionary of Visual Science, 4th ed)Plant Growth Regulators: Any of the hormones produced naturally in plants and active in controlling growth and other functions. There are three primary classes: auxins, cytokinins, and gibberellins.Phytochrome: A blue-green biliprotein widely distributed in the plant kingdom.Pigment Epithelium of Eye: The layer of pigment-containing epithelial cells in the RETINA; the CILIARY BODY; and the IRIS in the eye.Fluorescent Antibody Technique, Indirect: A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)Cryptochromes: Flavoproteins that function as circadian rhythm signaling proteins in ANIMALS and as blue-light photoreceptors in PLANTS. They are structurally-related to DNA PHOTOLYASES and it is believed that both classes of proteins may have originated from an earlier protein that played a role in protecting primitive organisms from the cyclical exposure to UV LIGHT.Eye: The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.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.Radiation Injuries, Experimental: Experimentally produced harmful effects of ionizing or non-ionizing RADIATION in CHORDATA animals.Horseshoe Crabs: An arthropod subclass (Xiphosura) comprising the North American (Limulus) and Asiatic (Tachypleus) genera of horseshoe crabs.Amino Acid Sequence: 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.Plant Immunity: The inherent or induced capacity of plants to withstand or ward off biological attack by pathogens.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.Retinal Pigment Epithelium: The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips (outer segments) of the RETINAL PHOTORECEPTOR CELLS. These epithelial cells are macroglia that perform essential functions for the photoreceptor cells, such as in nutrient transport, phagocytosis of the shed photoreceptor membranes, and ensuring retinal attachment.Peripherins: Type III intermediate filament proteins expressed mainly in neurons of the peripheral and CENTRAL NERVOUS SYSTEMS. Peripherins are implicated in neurite elongation during development and axonal regeneration after injury.Retinal Photoreceptor Cell Inner Segment: The inner portion of a retinal rod or a cone photoreceptor cell, situated between the PHOTORECEPTOR CONNECTING CILIUM and the synapse with the adjacent neurons (RETINAL BIPOLAR CELLS; RETINAL HORIZONTAL CELLS). The inner segment contains the cell body, the nucleus, the mitochondria, and apparatus for protein synthesis.Cone Opsins: Photosensitive proteins expressed in the CONE PHOTORECEPTOR CELLS. They are the protein components of cone photopigments. Cone opsins are classified by their peak absorption wavelengths.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.Recoverin: A neuronal calcium-sensor protein that is found in ROD PHOTORECEPTORS and CONE PHOTORECEPTORS. It interacts with G-PROTEIN-COUPLED RECEPTOR KINASE 1 in a Ca2+ dependent manner and plays an important role in PHOTOTRANSDUCTION.Animals, Genetically Modified: ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.Retinal Bipolar Cells: INTERNEURONS of the vertebrate RETINA containing two processes. They receive inputs from the RETINAL PHOTORECEPTOR CELLS and send outputs to the RETINAL GANGLION CELLS. The bipolar cells also make lateral connections in the retina with the RETINAL HORIZONTAL CELLS and with the AMACRINE CELLS.Plant Epidermis: A thin layer of cells forming the outer integument of seed plants and ferns. (Random House Unabridged Dictionary, 2d ed)Compound Eye, Arthropod: Light sensory organ in ARTHROPODS consisting of a large number of ommatidia, each functioning as an independent photoreceptor unit.Rats, Mutant Strains: Rats bearing mutant genes which are phenotypically expressed in the animals.3',5'-Cyclic-GMP Phosphodiesterases: Enzymes that catalyze the hydrolysis of cyclic GMP to yield guanosine-5'-phosphate.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Retinaldehyde: A carotenoid constituent of visual pigments. It is the oxidized form of retinol which functions as the active component of the visual cycle. It is bound to the protein opsin forming the complex rhodopsin. When stimulated by visible light, the retinal component of the rhodopsin complex undergoes isomerization at the 11-position of the double bond to the cis-form; this is reversed in "dark" reactions to return to the native trans-configuration.Retinal DiseasesUrodela: An order of the Amphibia class which includes salamanders and newts. They are characterized by usually having slim bodies and tails, four limbs of about equal size (except in Sirenidae), and a reduction in skull bones.Retinal Horizontal Cells: NEURONS in the inner nuclear layer of the RETINA that synapse with both the RETINAL PHOTORECEPTOR CELLS and the RETINAL BIPOLAR CELLS, as well as other horizontal cells. The horizontal cells modulate the sensory signal.Plant Stomata: Closable openings in the epidermis of plants on the underside of leaves. They allow the exchange of gases between the internal tissues of the plant and the outside atmosphere.Drosophila: 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.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Angiosperms: Members of the group of vascular plants which bear flowers. They are differentiated from GYMNOSPERMS by their production of seeds within a closed chamber (OVARY, PLANT). The Angiosperms division is composed of two classes, the monocotyledons (Liliopsida) and dicotyledons (Magnoliopsida). Angiosperms represent approximately 80% of all known living plants.Microspectrophotometry: Analytical technique for studying substances present at enzyme concentrations in single cells, in situ, by measuring light absorption. Light from a tungsten strip lamp or xenon arc dispersed by a grating monochromator illuminates the optical system of a microscope. The absorbance of light is measured (in nanometers) by comparing the difference between the image of the sample and a reference image.Guanylate Cyclase-Activating Proteins: Neuronal calcium sensor proteins that regulate the activation of membrane-bound GUANYLATE CYCLASE. They are primarily expressed in the RETINA where they play an important role in PHOTOTRANSDUCTION.Phytochrome A: The primary plant photoreceptor responsible for perceiving and mediating responses to far-red light. It is a PROTEIN-SERINE-THREONINE KINASE that is translocated to the CELL NUCLEUS in response to light signals.G-Protein-Coupled Receptor Kinase 1: A PROTEIN-SERINE-THREONINE KINASE that is found in PHOTORECEPTOR CELLS. It mediates light-dependent PHOSPHORYLATION of RHODOPSIN and plays an important role in PHOTOTRANSDUCTION.Phytochrome B: A plant photo regulatory protein that exists in two forms that are reversibly interconvertible by LIGHT. In response to light it moves to the CELL NUCLEUS and regulates transcription of target genes. Phytochrome B plays an important role in shade avoidance and mediates plant de-etiolation in red light.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Retinal Detachment: Separation of the inner layers of the retina (neural retina) from the pigment epithelium. Retinal detachment occurs more commonly in men than in women, in eyes with degenerative myopia, in aging and in aphakia. It may occur after an uncomplicated cataract extraction, but it is seen more often if vitreous humor has been lost during surgery. (Dorland, 27th ed; Newell, Ophthalmology: Principles and Concepts, 7th ed, p310-12).cis-trans-Isomerases: Enzymes that catalyze the rearrangement of geometry about double bonds. EC 5.2.FlavoproteinsThoracica: A superorder of marine CRUSTACEA, free swimming in the larval state, but permanently fixed as adults. There are some 800 described species, grouped in several genera, and comprising of two major orders of barnacles: stalked (Pedunculata) and sessile (Sessilia).Retinal Neurons: Nerve cells of the RETINA in the pathway of transmitting light signals to the CENTRAL NERVOUS SYSTEM. They include the outer layer of PHOTORECEPTOR CELLS, the intermediate layer of RETINAL BIPOLAR CELLS and AMACRINE CELLS, and the internal layer of RETINAL GANGLION CELLS.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Flowers: The reproductive organs of plants.Hippocalcin: A neuronal calcium-sensor protein that was initially found in the NEURONS of the HIPPOCAMPUS. It interacts with NEURONAL APOPTOSIS-INHIBITORY PROTEIN.Cyclic Nucleotide-Gated Cation Channels: A subgroup of cyclic nucleotide-regulated ION CHANNELS within the superfamily of pore-loop cation channels. They are expressed in OLFACTORY NERVE cilia and in PHOTORECEPTOR CELLS and some PLANTS.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Seedling: Very young plant after GERMINATION of SEEDS.Lycopersicon esculentum: A plant species of the family SOLANACEAE, native of South America, widely cultivated for their edible, fleshy, usually red fruit.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.Leber Congenital Amaurosis: A rare degenerative inherited eye disease that appears at birth or in the first few months of life that results in a loss of vision. Not to be confused with LEBER HEREDITARY OPTIC NEUROPATHY, the disease is thought to be caused by abnormal development of PHOTORECEPTOR CELLS in the RETINA, or by the extremely premature degeneration of retinal cells.Plant Poisoning: Poisoning by the ingestion of plants or its leaves, berries, roots or stalks. The manifestations in both humans and animals vary in severity from mild to life threatening. In animals, especially domestic animals, it is usually the result of ingesting moldy or fermented forage.In Situ Nick-End Labeling: An in situ method for detecting areas of DNA which are nicked during APOPTOSIS. Terminal deoxynucleotidyl transferase is used to add labeled dUTP, in a template-independent manner, to the 3 prime OH ends of either single- or double-stranded DNA. The terminal deoxynucleotidyl transferase nick end labeling, or TUNEL, assay labels apoptosis on a single-cell level, making it more sensitive than agarose gel electrophoresis for analysis of DNA FRAGMENTATION.Retinal Ganglion Cells: Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.Plant Transpiration: The loss of water vapor by plants to the atmosphere. It occurs mainly from the leaves through pores (stomata) whose primary function is gas exchange. The water is replaced by a continuous column of water moving upwards from the roots within the xylem vessels. (Concise Dictionary of Biology, 1990)Nerve Tissue ProteinsCircadian Rhythm: The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.Mollusca: A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.Models, Biological: 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.Mice, Inbred C57BLPhototropism: The directional growth of organisms in response to light. In plants, aerial shoots usually grow towards light. The phototropic response is thought to be controlled by auxin (= AUXINS), a plant growth substance. (From Concise Dictionary of Biology, 1990)Zebrafish: An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.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.Ocular Physiological Phenomena: Processes and properties of the EYE as a whole or of any of its parts.Plant Tumors: A localized proliferation of plant tissue forming a swelling or outgrowth, commonly with a characteristic shape and unlike any organ of the normal plant. Plant tumors or galls usually form in response to the action of a pathogen or a pest. (Holliday, P., A Dictionary of Plant Pathology, 1989, p330)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.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Plant Components, Aerial: The above-ground plant without the roots.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.Microscopy, Confocal: A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.Color Vision: Function of the human eye that is used in bright illumination or in daylight (at photopic intensities). Photopic vision is performed by the three types of RETINAL CONE PHOTORECEPTORS with varied peak absorption wavelengths in the color spectrum (from violet to red, 400 - 700 nm).Pineal Gland: A light-sensitive neuroendocrine organ attached to the roof of the THIRD VENTRICLE of the brain. The pineal gland secretes MELATONIN, other BIOGENIC AMINES and NEUROPEPTIDES.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.Green Fluorescent Proteins: 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.Optic Lobe, Nonmammalian: In invertebrate zoology, a lateral lobe of the FOREBRAIN in certain ARTHROPODS. In vertebrate zoology, either of the corpora bigemina of non-mammalian VERTEBRATES. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1329)Photobiology: The branch of biology dealing with the effect of light on organisms.Diptera: An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).Plant Preparations: Material prepared from plants.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Cyclic GMP: Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed)Basic-Leucine Zipper Transcription Factors: A large superfamily of transcription factors that contain a region rich in BASIC AMINO ACID residues followed by a LEUCINE ZIPPER domain.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.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.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.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Herbivory: The act of feeding on plants by animals.Power Plants: Units that convert some other form of energy into electrical energy.Transgenes: Genes that are introduced into an organism using GENE TRANSFER TECHNIQUES.Ciliary Neurotrophic Factor: A neurotrophic factor that promotes the survival of various neuronal cell types and may play an important role in the injury response in the nervous system.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.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.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.Photosynthesis: The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Biomass: Total mass of all the organisms of a given type and/or in a given area. (From Concise Dictionary of Biology, 1990) It includes the yield of vegetative mass produced from any given crop.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Mice, Mutant Strains: Mice bearing mutant genes which are phenotypically expressed in the animals.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Lipofuscin: A naturally occurring lipid pigment with histochemical characteristics similar to ceroid. It accumulates in various normal tissues and apparently increases in quantity with age.Amacrine Cells: INTERNEURONS of the vertebrate RETINA. They integrate, modulate, and interpose a temporal domain in the visual message presented to the RETINAL GANGLION CELLS, with which they synapse in the inner plexiform layer.Fabaceae: The large family of plants characterized by pods. Some are edible and some cause LATHYRISM or FAVISM and other forms of poisoning. Other species yield useful materials like gums from ACACIA and various LECTINS like PHYTOHEMAGGLUTININS from PHASEOLUS. Many of them harbor NITROGEN FIXATION bacteria on their roots. Many but not all species of "beans" belong to this family.Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Hypocotyl: The region of the stem beneath the stalks of the seed leaves (cotyledons) and directly above the young root of the embryo plant. It grows rapidly in seedlings showing epigeal germination and lifts the cotyledons above the soil surface. In this region (the transition zone) the arrangement of vascular bundles in the root changes to that of the stem. (From Concise Dictionary of Biology, 1990)Indoleacetic Acids: Acetic acid derivatives of the heterocyclic compound indole. (Merck Index, 11th ed)Membrane Proteins: 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.Plant Lectins: Protein or glycoprotein substances of plant origin that bind to sugar moieties in cell walls or membranes. Some carbohydrate-metabolizing proteins (ENZYMES) from PLANTS also bind to carbohydrates, however they are not considered lectins. Many plant lectins change the physiology of the membrane of BLOOD CELLS to cause agglutination, mitosis, or other biochemical changes. They may play a role in plant defense mechanisms.Protein Transport: 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.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Plant Nectar: Sugar-rich liquid produced in plant glands called nectaries. It is either produced in flowers or other plant structures, providing a source of attraction for pollinating insects and animals, as well as being a nutrient source to animal mutualists which provide protection of plants against herbivores.Guanylate Cyclase: An enzyme that catalyzes the conversion of GTP to 3',5'-cyclic GMP and pyrophosphate. It also acts on ITP and dGTP. (From Enzyme Nomenclature, 1992) EC 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.Microscopy, 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.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Retinol-Binding Proteins: Proteins which bind with RETINOL. The retinol-binding protein found in plasma has an alpha-1 mobility on electrophoresis and a molecular weight of about 21 kDa. The retinol-protein complex (MW=80-90 kDa) circulates in plasma in the form of a protein-protein complex with prealbumin. The retinol-binding protein found in tissue has a molecular weight of 14 kDa and carries retinol as a non-covalently-bound ligand.Oxylipins: Eighteen-carbon cyclopentyl polyunsaturated fatty acids derived from ALPHA-LINOLENIC ACID via an oxidative pathway analogous to the EICOSANOIDS in animals. Biosynthesis is inhibited by SALICYLATES. A key member, jasmonic acid of PLANTS, plays a similar role to ARACHIDONIC ACID in animals.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Bufo marinus: A species of the true toads, Bufonidae, becoming fairly common in the southern United States and almost pantropical. The secretions from the skin glands of this species are very toxic to animals.Cell Death: The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.Eye Diseases, Hereditary: Transmission of gene defects or chromosomal aberrations/abnormalities which are expressed in extreme variation in the structure or function of the eye. These may be evident at birth, but may be manifested later with progression of the disorder.Color Vision Defects: Defects of color vision are mainly hereditary traits but can be secondary to acquired or developmental abnormalities in the CONES (RETINA). Severity of hereditary defects of color vision depends on the degree of mutation of the ROD OPSINS genes (on X CHROMOSOME and CHROMOSOME 3) that code the photopigments for red, green and blue.DNA, Complementary: 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.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)Microscopy, Fluorescence: 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.DNA Primers: 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.Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.Tomography, Optical Coherence: An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.Plant Bark: The outer layer of the woody parts of plants.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).Symbiosis: The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.Plant Physiological Processes: Physiological functions characteristic of plants.Cyclopentanes: A group of alicyclic hydrocarbons with the general formula R-C5H9.Germination: The initial stages of the growth of SEEDS into a SEEDLINGS. The embryonic shoot (plumule) and embryonic PLANT ROOTS (radicle) emerge and grow upwards and downwards respectively. Food reserves for germination come from endosperm tissue within the seed and/or from the seed leaves (COTYLEDON). (Concise Dictionary of Biology, 1990)Solanum tuberosum: A plant species of the genus SOLANUM, family SOLANACEAE. The starchy roots are used as food. SOLANINE is found in green parts.Chloroplasts: Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.Soil: The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.Hermissenda: A genus of marine sea slugs in the family Glaucidae, superorder GASTROPODA, found on the Pacific coast of North America. They are used in behavioral and neurological laboratory studies.Macular Degeneration: Degenerative changes in the RETINA usually of older adults which results in a loss of vision in the center of the visual field (the MACULA LUTEA) because of damage to the retina. It occurs in dry and wet forms.Microscopy, Electron, Transmission: Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.Intermediate Filament Proteins: Filaments 7-11 nm in diameter found in the cytoplasm of all cells. Many specific proteins belong to this group, e.g., desmin, vimentin, prekeratin, decamin, skeletin, neurofilin, neurofilament protein, and glial fibrillary acid protein.Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Medicine, Traditional: Systems of medicine based on cultural beliefs and practices handed down from generation to generation. The concept includes mystical and magical rituals (SPIRITUAL THERAPIES); PHYTOTHERAPY; and other treatments which may not be explained by modern medicine.Houseflies: Flies of the species Musca domestica (family MUSCIDAE), which infest human habitations throughout the world and often act as carriers of pathogenic organisms.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Fundus Oculi: The concave interior of the eye, consisting of the retina, the choroid, the sclera, the optic disk, and blood vessels, seen by means of the ophthalmoscope. (Cline et al., Dictionary of Visual Science, 4th ed)Plant Exudates: Substances released by PLANTS such as PLANT GUMS and PLANT RESINS.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)Kinetics: The rate dynamics in chemical or physical systems.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.