Members of the phylum Arthropoda, composed of organisms having a hard, jointed exoskeleton and paired jointed legs. It includes the class INSECTS and the subclass ARACHNIDA, many species of which are important medically as parasites or as vectors of organisms capable of causing disease in man.
Light sensory organ in ARTHROPODS consisting of a large number of ommatidia, each functioning as an independent photoreceptor unit.
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.
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.
Processes and properties of the EYE as a whole or of any of its parts.
Arthropods, other than insects and arachnids, which transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.
A large subphylum of mostly marine ARTHROPODS containing over 42,000 species. They include familiar arthropods such as lobsters (NEPHROPIDAE), crabs (BRACHYURA), shrimp (PENAEIDAE), and barnacles (THORACICA).
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)
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).
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.
The class Insecta, in the phylum ARTHROPODA, whose members are characterized by division into three parts: head, thorax, and abdomen. They are the dominant group of animals on earth; several hundred thousand different kinds having been described. Three orders, HEMIPTERA; DIPTERA; and SIPHONAPTERA; are of medical interest in that they cause disease in humans and animals. (From Borror et al., An Introduction to the Study of Insects, 4th ed, p1)
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.
Proteins found in any species of insect.
Diseases affecting the eye.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
Voluntary or reflex-controlled movements of the eye.
Insect members of the superfamily Apoidea, found almost everywhere, particularly on flowers. About 3500 species occur in North America. They differ from most WASPS in that their young are fed honey and pollen rather than animal food.
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.
A genus in the family Blattidae containing several species, the most common being P. americana, the American cockroach.
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.
Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.
Arthropods of the class ARACHNIDA, order Araneae. Except for mites and ticks, spiders constitute the largest order of arachnids, with approximately 37,000 species having been described. The majority of spiders are harmless, although some species can be regarded as moderately harmful since their bites can lead to quite severe local symptoms. (From Barnes, Invertebrate Zoology, 5th ed, p508; Smith, Insects and Other Arthropods of Medical Importance, 1973, pp424-430)
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.
A ready-made or custom-made prosthesis of glass or plastic shaped and colored to resemble the anterior portion of a normal eye and used for cosmetic reasons. It is attached to the anterior portion of an orbital implant (ORBITAL IMPLANTS) which is placed in the socket of an enucleated or eviscerated eye. (From Dorland, 28th ed)
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.
Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.
The relationships of groups of organisms as reflected by their genetic makeup.
Plant-eating orthopterans having hindlegs adapted for jumping. There are two main families: Acrididae and Romaleidae. Some of the more common genera are: Melanoplus, the most common grasshopper; Conocephalus, the eastern meadow grasshopper; and Pterophylla, the true katydid.
Insects of the order Dictyoptera comprising several families including Blaberidae, BLATTELLIDAE, Blattidae (containing the American cockroach PERIPLANETA americana), Cryptocercidae, and Polyphagidae.
The functional hereditary units of INSECTS.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Set of cell bodies and nerve fibers conducting impulses from the eyes to the cerebral cortex. It includes the RETINA; OPTIC NERVE; optic tract; and geniculocalcarine tract.
The anterior pair of the quadrigeminal bodies which coordinate the general behavioral orienting responses to visual stimuli, such as whole-body turning, and reaching.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
An inactive stage between the larval and adult stages in the life cycle of insects.
A class of Arthropoda that includes SPIDERS; TICKS; MITES; and SCORPIONS.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.
The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.
The use of wings or wing-like appendages to remain aloft and move through the air.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
Damage or trauma inflicted to the eye by external means. The concept includes both surface injuries and intraocular injuries.
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.
A genus of bacteria comprised of a heterogenous group of gram-negative small rods and coccoid forms associated with arthropods. (From Bergey's Manual of Systematic Bacteriology, vol 1, 1984)
A specialized field of physics and engineering involved in studying the behavior and properties of light and the technology of analyzing, generating, transmitting, and manipulating ELECTROMAGNETIC RADIATION in the visible, infrared, and ultraviolet range.
The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.
An interdisciplinary field in materials science, ENGINEERING, and BIOLOGY, studying the use of biological principles for synthesis or fabrication of BIOMIMETIC MATERIALS.
Corneal and conjunctival dryness due to deficient tear production, predominantly in menopausal and post-menopausal women. Filamentary keratitis or erosion of the conjunctival and corneal epithelium may be caused by these disorders. Sensation of the presence of a foreign body in the eye and burning of the eyes may occur.
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)
Profound physical changes during maturation of living organisms from the immature forms to the adult forms, such as from TADPOLES to frogs; caterpillars to BUTTERFLIES.
Proteins synthesized by organisms belonging to the phylum ARTHROPODA. Included in this heading are proteins from the subdivisions ARACHNIDA; CRUSTACEA; and HORSESHOE CRABS. Note that a separate heading for INSECT PROTEINS is listed under this heading.
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.
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.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
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.
An infraorder of chiefly marine, largely carnivorous CRUSTACEA, in the order DECAPODA, including the genera Cancer, Uca, and Callinectes.
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.
Animals that have no spinal column.
Congenital absence of or defects in structures of the eye; may also be hereditary.
Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The total area or space visible in a person's peripheral vision with the eye looking straightforward.
Venoms from animals of the phylum Arthropoda. Those most investigated are from scorpions and spiders of the class Arachnidae and from ant, bee, and wasp families of the Insecta order Hymenoptera. The venoms contain protein toxins, enzymes, and other bioactive substances and may be lethal to man.
Injury to any part of the eye by extreme heat, chemical agents, or ultraviolet radiation.
A discipline or occupation concerned with the study of INSECTS, including the biology and the control of insects.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
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.
INSECTS of the order Coleoptera, containing over 350,000 species in 150 families. They possess hard bodies and their mouthparts are adapted for chewing.
Arthropods of the order Scorpiones, of which 1500 to 2000 species have been described. The most common live in tropical or subtropical areas. They are nocturnal and feed principally on insects and other arthropods. They are large arachnids but do not attack man spontaneously. They have a venomous sting. Their medical significance varies considerably and is dependent on their habits and venom potency rather than on their size. At most, the sting is equivalent to that of a hornet but certain species possess a highly toxic venom potentially fatal to humans. (From Dorland, 27th ed; Smith, Insects and Other Arthropods of Medical Importance, 1973, p417; Barnes, Invertebrate Zoology, 5th ed, p503)
The surgical removal of the eyeball leaving the eye muscles and remaining orbital contents intact.
A phylum of metazoan invertebrates comprising the segmented worms, and including marine annelids (POLYCHAETA), freshwater annelids, earthworms (OLIGOCHAETA), and LEECHES. Only the leeches are of medical interest. (Dorland, 27th ed)
Color of the iris.
A genus of small beetles of the family Tenebrionidae; T. confusum is the "confused flour beetle".
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).
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
One of the largest orders of mostly marine CRUSTACEA, containing over 10,000 species. Like AMPHIPODA, the other large order in the superorder Peracarida, members are shrimp-like in appearance, have sessile compound eyes, and no carapace. But unlike Amphipoda, they possess abdominal pleopods (modified as gills) and their bodies are dorsoventrally flattened.
Inorganic or organic compounds that contain sulfur as an integral part of the molecule.
A yellowish fossil resin, the gum of several species of coniferous trees, found in the alluvial deposits of northeastern Germany. It is used in molecular biology in the analysis of organic matter fossilized in amber.
Family of spider MITES, in the superfamily Tetranychoidea, suborder Trombidiformes.
The real or apparent movement of objects through the visual field.
Blood-sucking acarid parasites of the order Ixodida comprising two families: the softbacked ticks (ARGASIDAE) and hardbacked ticks (IXODIDAE). Ticks are larger than their relatives, the MITES. They penetrate the skin of their host by means of highly specialized, hooked mouth parts and feed on its blood. Ticks attack all groups of terrestrial vertebrates. In humans they are responsible for many TICK-BORNE DISEASES, including the transmission of ROCKY MOUNTAIN SPOTTED FEVER; TULAREMIA; BABESIOSIS; AFRICAN SWINE FEVER; and RELAPSING FEVER. (From Barnes, Invertebrate Zoology, 5th ed, pp543-44)
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
Organic compounds that have a relatively high VAPOR PRESSURE at room temperature.
Any arthropod of the subclass ACARI except the TICKS. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans and domestic animals, producing various irritations of the skin (MITE INFESTATIONS). Many mite species are important to human and veterinary medicine as both parasite and vector. Mites also infest plants.
Centers for storing various parts of the eye for future use.
Instinctual behavior pattern in which food is obtained by killing and consuming other species.
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.
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.
An arthropod subclass (Xiphosura) comprising the North American (Limulus) and Asiatic (Tachypleus) genera of horseshoe crabs.
Renewal or physiological repair of damaged nerve tissue.
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.
An order of parasitic, blood-sucking, wingless INSECTS with the common name of fleas.
A large, subclass of arachnids comprising the MITES and TICKS, including parasites of plants, animals, and humans, as well as several important disease vectors.
Periodic casting off FEATHERS; HAIR; or cuticle. Molting is a process of sloughing or desquamation, especially the shedding of an outer covering and the development of a new one. This phenomenon permits growth in ARTHROPODS, skin renewal in AMPHIBIANS and REPTILES, and the shedding of winter coats in BIRDS and MAMMALS.
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.
A diverse genus of minute freshwater CRUSTACEA, of the suborder CLADOCERA. They are a major food source for both young and adult freshwater fish.
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.
A plant genus of the family FABACEAE. Members contain STILBENES.
The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
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)
The variety of all native living organisms and their various forms and interrelationships.
Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.
Tumors or cancer of the EYE.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.
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.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
Personal devices for protection of the eyes from impact, flying objects, glare, liquids, or injurious radiation.
Preclinical testing of drugs in experimental animals or in vitro for their biological and toxic effects and potential clinical applications.
The act of feeding on plants by animals.
A large order of insects characterized by having the mouth parts adapted to piercing or sucking. It is comprised of four suborders: HETEROPTERA, Auchenorrhyncha, Sternorrhyncha, and Coleorrhyncha.
Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.
Insects of the family Formicidae, very common and widespread, probably the most successful of all the insect groups. All ants are social insects, and most colonies contain three castes, queens, males, and workers. Their habits are often very elaborate and a great many studies have been made of ant behavior. Ants produce a number of secretions that function in offense, defense, and communication. (From Borror, et al., An Introduction to the Study of Insects, 4th ed, p676)
The largest genus of TICKS in the family IXODIDAE, containing over 200 species. Many infest humans and other mammals and several are vectors of diseases such as LYME DISEASE, tick-borne encephalitis (ENCEPHALITIS, TICK-BORNE), and KYASANUR FOREST DISEASE.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.

Dissecting Nck/Dock signaling pathways in Drosophila visual system. (1/111)

The establishment of neuronal connections during embryonic development requires the precise guidance and targeting of the neuronal growth cone, an expanded cellular structure at the leading tip of a growing axon. The growth cone contains sophisticated signaling systems that allow the rapid communication between guidance receptors and the actin cytoskeleton in generating directed motility. Previous studies demonstrated a specific role for the Nck/Dock SH2/SH3 adapter protein in photoreceptor (R cell) axon guidance and target recognition in the Drosophila visual system, suggesting strongly that Nck/Dock is one of the long-sought missing links between cell surface receptors and the actin cytoskeleton. In this review, I discuss the recent progress on dissecting the Nck/Dock signaling pathways in R-cell growth cones. These studies have identified additional key components of the Nck/Dock signaling pathways for linking the receptor signaling to the remodeling of the actin cytoskeleton in controlling growth-cone motility.  (+info)

Genetic dissection of the photoreceptor system in the compound eye of Drosophila melanogaster. (2/111)

Three mutations which eliminate specific types of photoreceptors in Drosophila were characterized. Of the eight photoreceptors in each facet, two mutations delete the outer six (R 1-6). The third eliminates R 7, one of the two central photoreceptors. Double mutants can be constructed in which only photoreceptor R 8 is present. The spectral sensitivities, photopigments, and behavioural properties of these mutants were investigated. R 1-6 have two sensitivity peaks, near 350 and 470 nm. These receptors contain a rhodopsin with these absorption peaks. It interconverts with a metarhodopsin that absorbs around 570 nm. R 7 is a U.V.-receptor, containing rhodopsin that absorbs around 370 nm and interconverts with a metarhodopsin which absorbs around 470 nm. R 8 is a non-adapting blue-receptor with a third type of rhodopsin. The properties of these photopigments explain the different sensitivities and spectral adaptation phenomena of the various photoreceptors. All the photoreceptors have input into phototaxis. Spectral analysis of this behaviour provides evidence for integration of the input from the different photoreceptors.  (+info)

Eye development under the control of SRp55/B52-mediated alternative splicing of eyeless. (3/111)

The genetic programs specifying eye development are highly conserved during evolution and involve the vertebrate Pax-6 gene and its Drosophila melanogaster homolog eyeless (ey). Here we report that the SR protein B52/SRp55 controls a novel developmentally regulated splicing event of eyeless that is crucial for eye growth and specification in Drosophila. B52/SRp55 generates two isoforms of eyeless differing by an alternative exon encoding a 60-amino-acid insert at the beginning of the paired domain. The long isoform has impaired ability to trigger formation of ectopic eyes and to bind efficiently Eyeless target DNA sequences in vitro. When over-produced in the eye imaginal disc, this isoform induces a small eye phenotype, whereas the isoform lacking the alternative exon triggers eye over-growth and strong disorganization. Our results suggest that B52/SRp55 splicing activity is used during normal eye development to control eye organogenesis and size through regulation of eyeless alternative splicing.  (+info)

Mutation of the Apc1 homologue shattered disrupts normal eye development by disrupting G1 cell cycle arrest and progression through mitosis. (4/111)

The shattered1 (shtd1) mutation disrupts Drosophila compound eye structure. In this report, we show that the shtd1 eye defects are due to a failure to establish and maintain G1 arrest in the morphogenetic furrow (MF) and a defect in progression through mitosis. The observed cell cycle defects were correlated with an accumulation of cyclin A (CycA) and String (Stg) proteins near the MF. Interestingly, the failure to maintain G1 arrest in the MF led to the specification of R8 photoreceptor cells that undergo mitosis, generating R8 doublets in shtd1 mutant eye discs. We demonstrate that shtd encodes Apc1, the largest subunit of the anaphase-promoting complex/cyclosome (APC/C). Furthermore, we show that reducing the dosage of either CycA or stg suppressed the shtd1 phenotype. While reducing the dosage of CycA is more effective in suppressing the premature S phase entry in the MF, reducing the dosage of stg is more effective in suppressing the progression through mitosis defect. These results indicate the importance of not only G1 arrest in the MF but also appropriate progression through mitosis for normal eye development during photoreceptor differentiation.  (+info)

Identification of transcriptional targets of the dual-function transcription factor/phosphatase eyes absent. (5/111)

Drosophila eye specification and development relies on a collection of transcription factors termed the retinal determination gene network (RDGN). Two members of this network, Eyes absent (EYA) and Sine oculis (SO), form a transcriptional complex in which EYA provides the transactivation function while SO provides the DNA binding activity. EYA also functions as a protein tyrosine phosphatase, raising the question of whether transcriptional output is dependent or independent of phosphatase activity. To explore this, we used microarrays together with binding site analysis, quantitative real-time PCR, chromatin immunoprecipitation, genetics and in vivo expression analysis to identify new EYA-SO targets. In parallel, we examined the expression profiles of tissue expressing phosphatase mutant eya and found that reducing phosphatase activity did not globally impair transcriptional output. Among the targets identified by our analysis was the cell cycle regulatory gene, string (stg), suggesting that EYA and SO may influence cell proliferation through transcriptional regulation of stg. Future investigation into the regulation of stg and other EYA-SO targets identified in this study will help elucidate the transcriptional circuitries whereby output from the RDGN integrates with other signaling inputs to coordinate retinal development.  (+info)

A new allele uncovers the role of echinus in the control of ommatidial rotation in the Drosophila eye. (6/111)

The precise orientation of the ommatidia in the Drosophila eye is achieved through a specialized process of cell migration taking place in the third-instar eye imaginal disc when ommatidial clusters rotate by 90 degrees. This process is strictly coordinated with the establishment of planar cell polarity (PCP), but it relies on a specific set of genes that control its mechanism independently from PCP signaling. Recently, the epidermal growth factor receptor (EGFR) pathway has been implicated in determining ommatidial rotation. We have isolated a new allele of echinus, a gene known to control the patterning and number of interommatidial cells. We show that echinus displays defects in the rotation of ommatidia that are not evident until mid-pupal stages, and we propose that echinus action is that of opposing EGFR by an unknown mechanism and that this can explain both its influence in ommatidial rotation and lattice programmed cell death (PCD).  (+info)

Gene-specific targeting of the histone chaperone asf1 to mediate silencing. (7/111)

The histone chaperone Asf1 assists in chromatin assembly and remodeling during replication, transcription activation, and gene silencing. However, it has been unclear to what extent Asf1 could be targeted to specific loci via interactions with sequence-specific DNA-binding proteins. Here, we show that Asf1 contributes to the repression of Notch target genes, as depletion of Asf1 in cells by RNAi causes derepression of the E(spl) Notch-inducible genes. Conversely, overexpression of Asf1 in vivo results in decreased expression of target genes and produces phenotypes that are strongly modified (enhanced and suppressed) by mutations affecting the Notch pathway, but not by mutations in other signaling pathways. Asf1 can be coprecipitated with the DNA-binding protein Su(H) and the corepressor Hairless and interacts directly with two components of this complex, Hairless and SKIP. Thus, in addition to playing more general roles in chromatin dynamics, Asf1 is directed via interactions with sequence-specific complexes to mediate silencing of specific target genes.  (+info)

Myosin II regulates complex cellular arrangement and epithelial architecture in Drosophila. (8/111)

Remodeling epithelia is a primary driver of morphogenesis. Here, we report a central role of myosin II in regulating several aspects of complex epithelial architecture in the Drosophila eye imaginal disc. The epithelial indentation of the morphogenetic furrow is established from a pattern of myosin II activation defined by the developmental signals Hedgehog and Decapentaplegic. More generally, patterned myosin activation can control diverse three-dimensional epithelial sculpting. We have developed a technique to image eye disc development in real time, and we show that myosin II also regulates higher-order organization of cells in the plane of the epithelium. This includes the clustering of cells into ommatidial units and their subsequent coordinated rotation. This later clustering function of myosin II depends on EGF receptor signaling. Our work implies that regulation of the actomyosin cytoskeleton can control morphogenesis by regulating both individual cell shapes and their complex two-dimensional arrangement within epithelia.  (+info)

Rossi, A., Cicoira, M., Florea, V. G., Golia, G., Florea, N. D., Khan, A. A., Murray, S. T. M., Nguyen, J. T., OCallaghan, P., Anand, I. S., Coats, A., Zardini, P., Vassanelli, C. & Henein, M., Jun 28 2006, In : International Journal of Cardiology. 110, 3, p. 386-392 7 p.. Research output: Contribution to journal › Article ...
In all arthropods the plesiomorphic (ancestral character state) kind of visual system commonly is considered to be the compound eye. Here we are able to show the excellently preserved internal structures of the compound eye of a 429 Mya old Silurian trilobite, Aulacopleura koninckii (Barrande, 1846). It shows the characteristic elements of a modern apposition eye, consisting of 8 (visible) receptor cells, a rhabdom, a thick lens, screening pigment (cells), and in contrast to a modern type, putatively just a very thin crystalline cone. Functionally the latter underlines the idea of a primarily calcitic character of the lens because of its high refractive properties. Perhaps the trilobite was translucent. We show that this Palaeozoic trilobite in principle was equipped with a fully modern type of visual system, a compound eye comparable to that of living bees, dragonflies and many diurnal crustaceans. It is an example of excellent preservation, and we hope that this manuscript will be a starting point for
The structure and function of compound eyes in crustaceans and insects has been the subject of intense study over the last 120 years (e.g. Exner, 1891; Horridge, 1975; Strausfeld, 2005; Warrant, 2006; Land and Nilsson, 2012); however, comparatively little is known about the ocelli (for reviews, see Goodman, 1981; Mizunami, 1995; Krapp, 2009). Adult winged insects usually have three ocelli on the frons or vertex, a median ocellus and two lateral ones - not to be confused with stemmata, which are sometimes termed lateral ocelli as well. From a morphological point of view, they are simple eyes in that they have a single lens. Ocelli are often more sensitive than compound eyes, because of a high convergence of photoreceptors onto secondary neurons, and the fewer neurons involved in processing the signals enable a faster response. The insight that the ocelli of some taxa are capable of any resolution at all is relatively recent (Schuppe and Hengstenberg, 1993; Stange et al., 2002; Berry et al., ...
Compound eyes are types of eyes made up of many repeating units called ommatidia. These types of eyes are mainly present in insects, although some crustaceans, such as crayfish, also possess them. A...
n. sp.. ( Figs 8-14View FIGURES 8 - 14). Color. Body pale yellow, with brown and pale brown areas as indicated below. Compound eyes black, ocelli hyaline, with ochre centripetal crescents; head pattern ( Fig. 8View FIGURES 8 - 14); a brown area on vertex, close to each compound eye, as illustrated, also a brown band between compound eyes, below the level of the ocellar group, limited posteriorly by the postclypeus; a brown band on each gena, from lower compound eye to subgenal sulcus. Antennae and maxillary palps pale yellow, Mx 4 more pigmented distally. Tergal lobes of meso- and metathorax brown; thoracic pleura with an irregular pale brown band above the level of the coxae. Legs with coxae, trochanters and femora creamy white, tibiae and tarsomeres pale yellow. Forewings almost hyaline, as illustrated ( Fig. 9View FIGURES 8 - 14); a brown spot on confluence of Cu 2 - 1 A; veins brown. Hindwing ( Fig. 10View FIGURES 8 - 14), almost hyaline throughout, veins brown.. Structural characters. ...
Aceasta publicatie este distribuita gratuit si se adreseaza în special parintilor care au copii cu deficiente de auz dar si cadrelor didacti ...
De Bruin, G., Li, N., Paniagua, G., Willems, L., Xin, B. T., Verdoes, M., Geurink, P. P., Van Der Linden, W., van der Stelt, M., Van Der Marel, G., Overkleeft, H. S. & Florea, B. I., 6 Oct 2014, Concepts and Case Studies in Chemical Biology. Wiley-Blackwell, p. 177-190 14 p.. Research output: Chapter in Book/Report/Conference proceeding › Chapter ...
Muheim, R., Moore, F. R. and Phillips, J. B. (2006). Calibration of magnetic and celestial compass cues in migratory birds - a review of cue-conflict experiments. J. Exp. Biol. 209, 2-17.. The final paragraph before the `General discussion (p. 11) was based on a misunderstanding and should be replaced by the following paragraph:. It was previously argued that during migration only one exposure to the cue conflict would lead to a dominance of celestial cues, and thus to a recalibration of the magnetic compass, while repeated exposures to the cue conflict would lead to a dominance of magnetic cues and to a recalibration of the celestial compass(es) (e.g. Wiltschko et al., 1997; Wiltschko et al., 1998a; Wiltschko and Wiltschko, 1999). According to our analysis, the birds did not show a significant reaction to the shifted magnetic field, i.e. they followed celestial rather than magnetic cues in four of 23 experiments in which birds were exposed to a shifted magnetic field with access to celestial ...
Get information, facts, and pictures about compound eye at Make research projects and school reports about compound eye easy with credible articles from our FREE, online encyclopedia and dictionary.
Ilinca feat. Alex Florea will represent Romania at Eurovision 2017 with Yodel It!. Read the lyrics here. Yodeleeii, yodeleioo
Dr. Andrew S Florea, MD, rated 3/5 by patients. 17 reviews, Phone number & practice locations, Otolaryngologist in Redlands, CA.
Cells that received Dpp and activated Dpp signal transduction extended cytonemes that directly contacted Dpp-producing cells. The contacts were characterized by relative stability and membrane juxtaposition of less than 15 nm. Cytonemes that contained the Dpp receptor in motile puncta also contained Dpp taken up from Dpp-producing cells. In contrast, a different set of cytonemes that contacted fibroblast growth factor (FGF)-producing cells contained the FGF receptor but did not take up Dpp. The cytonemes were reduced in number and length in genetic loss-of-function conditions for diaphanous, which encodes a formin; for neuroglian, which encodes an L1-type cell adhesion molecule; and for shibire, which encodes a dynamin. Cytonemes were present in loss-of-function conditions for capricious, which encodes a leucine-rich repeat cell adhesion protein, but these cytonemes failed to contact Dpp-producing cells. Signaling was abrogated in all these conditions that created defective cytonemes, although ...
In the developing Drosophila compound eye, a wave of pattern formation and cell-type determination sweeps across the presumptive eye epithelium. This morphogenetic furrow coordinates the epithelial cells division cycle, shape and gene expression to produce evenly spaced neural cell clusters that will eventually form the adult ommatidia. As these clusters develop, they rotate inwards to face the eyes equator and establish tissue polarity. We have found that wingless is strongly expressed in the dorsal margin of the presumptive eye field, ahead of the morphogenetic furrow. We have shown that inactivation of Wingless results in the induction of an ectopic furrow that proceeds ventrally from the dorsal margin. This ectopic furrow is normal in most respects, however the clusters formed by it fail to rotate, and we propose a two-vector model to account for normal rotation and tissue polarity in the retina. A second consequence of this inactivation of Wingless is that the dorsal head is largely ...
In Xenopus embryos at stages 28-32 one quarter to one third of the left eye rudiment was replaced by a similarly sized piece from a different position in a right eye rudiment. Three groups of operations were performed: (1) temporal tissue was placed in a nasal position; (2) nasal tissue was placed temporally; (3) ventral tissue was placed dorsally. The visuotectal projections made by these pie-slice compound eyes were assessed electrophysiologically at 1 week to 6 months after metamorphosis. Of 97 animals, 71 yielded interpretable projections. In most cases two projections could be identified in each map. One, ascribed to the host part of the retina, extended over the entire tectal surface mapped. The other, identified as that from tissue derived from the pie-slice graft, projected to the tectum in register with that part of the host retina which matched the pie-slice in origin. Both projections were well ordered, and in the orientation expected if the corresponding piece of retinal tissue had ...
The morphogenetic furrow is a dorsoventral indentation which sweeps anteriorly across the eye disc. Ommatidia begin to form along the furrow, resulting in a graded series of ommatidial development across the anterior/posterior axis of the disc.
Ocelli : Two types of simple eyes can be found in the class Insecta: dorsal Ocelli and lateral Ocelli (=stemmata). Although both types of Ocelli are similar in structure, they are believed to have separate phylogenetic and embryological origins. Dorsal Ocelli are commonly found in adults and in the immature stages (nymphs) of many hemimetabolous species. They are not independent visual organs and never occur in species that lack compound eyes. Whenever present, dorsal Ocelli appear as two or three small, convex swellings on the dorsal or facial regions of the head. They differ from compound eyes in having only a single corneal lens covering an array of several dozen rhabdom-like sensory rods. These simple eyes do not form an image or perceive objects in the environment, but they are sensitive to a wide range of wavelengths, react to the polarization of light, and respond quickly to changes in light intensity. No exact function has been clearly established, but many physiologists believe they ...
Blocked by a wall of five horses exiting the final turn, Steve Mogers Stormy Lucy found space to the outside and just got up to catch Recepta at the wire to win the $300,000 Matriarch Stakes (gr. IT) Nov. 29 at Del Mar.. ...
Sybrin P. Schröder, Jasper W. van de Sande, Wouter W. Kallemeijn, Chi-Lin Kuo, Marta Artola, Eva J. van Rooden, Jianbing Jiang, Thomas J. M. Beenakker, Bogdan I. Florea, Wendy A. Offen, Gideon J. Davies, Adriaan J. Minnaard, Johannes M. F. G. Aerts, Jeroen D. C. Codée, Gijsbert A. van der Marel and Herman S. ...
Willems, L. I., Beenakker, T. J. M., Murray, B. S., Scheij, S., Kallemeijn, W. W., Boot, R. G., Verhoek, M., Donker-Koopman, W. E., Ferraz, M. J., Rijssel, E. R. V., Florea, B. I., Codée, J. D. C., Van Der Marel, G. A., Aerts, J. M. F. G. & Overkleeft, H. S., 8 Aug 2014. Article in Journal of the American Chemical Society ...
Definition: superposition compound eyes where each ommatidium is equipped with a lens cylinder arrangement, producing the equivalent of a pair of lenses, with the first lens producing a small image halfway down the structure and the second lens turning the image back into a parallel beam. In the process the ray direction is reversed. Thus, the emerging beam is on the same side of the axis as the entering beam-the condition for obtaining a superposition image from the whole array ...
1787 - 1835. Daughter of free Mulatto lodging-house-keeper Jane Charlotte Beckford (c. 1759-1825); possibly the daughter of George Ffrench, Clerk to the Jamaica Assembly. Spinster; independently wealthy slave-owner.. Visit the people of interest section. ...
1787 - 1835. Daughter of free Mulatto lodging-house-keeper Jane Charlotte Beckford (c. 1759-1825); possibly the daughter of George Ffrench, Clerk to the Jamaica Assembly. Spinster; independently wealthy slave-owner.. Visit the people of interest section. ...
DCU ConnectedconnectedWhat if you could work towards a world-class online Irish University degree on your own schedule, from the comfort of your own home, in your own town, in any place in the world? Online learning with DCU Connected gives you remote access to all the resources of an established university: an innovative curriculum, renowned teachers and lively exchange with your fellow learners.
Our study involves the analysis of normal and abnormal cells in the bone marrow of patients with Paroxysmal Nocturnal Hemoglobinuria (PNH). In this condition, due to a gene mutation, some bone marrow cells and their progeny in the blood lack an important cell surface component that functions as an anchor for other proteins, some of which attach to blood cells and protect them from destruction by complement, part our immune system. The result of this deficiency is a breakdown of red cells. If large quantities of red cells are destroyed, people become very tired, or have pain in the belly, head or when swallowing, or develop blood clots. The cause of the gene mutation is unknown. Some patients with other conditions, such as aplastic anemia (AA, a disease where marrow stops producing blood cells), or myelodysplasia (MDS, a disease associated with a tendency to transform into leukemia), may develop PNH. It is not clear what makes this change occur, and when it happens, patient may not even be aware ...
Bristletails are primitive wingless insects. At first glance they resemble silverfish, however silverfish have three abdominal filaments nearly equal in length. In bristletails, the central filament is much longer than the side two. Unlike silverfish, bristletails have well developed compound eyes. The compound eyes are large and meet on the back of the head. Three simple eyes (ocelli) also occur on bristletails. Bristletails have well developed mandibles which are partially hidden in the head. The antennae are long and resemble a chain of beads (moniliform). Bristletails are usually nocturnal and have an interesting habit of arching and flexing the body to give a springing action similar to springtails. Bristletails are found in litter, moss, lichens and other similar habitats ...
An organisms senses connect it to the outside world and are essential in allowing it to react adequately to environmental stimuli. As the structure of sensory organs is limited by the physical properties of the signals they are supposed to pick up (e.g. light, sound), it is not surprising that they represent prime examples of evolutionary convergence.. With respect to vision, classic cases of convergence include the camera eye (which has not only been invented by cephalopods and vertebrates but also by several other groups) and the compound eye (famously found in arthropods as well as in other invertebrates). Colour vision has evolved multiple times in insects and vertebrates, but remarkably is also found in mantid shrimps, highly effective predators with complex compound eyes. Vertebrates are primitively tetrachromatic (having four different types of cone cells with different light absorption spectra), but most mammals are dichromatic, which might reflect a transition to a nocturnal way of ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Coni, you need to get your shit together. Excuse my bluntness, but you are a mess and you are seemingly oblivious to the consequences. You can joke and make funny snappy comebacks but it is way past the time for you to get serious. This is your life at stake. Not a missed stitch, not a lost house, not an asshole sister - your life. Does anything else even matter? Or come close? Stop calling your port by a silly little name. It is not a silly little personality, its a medical intervention to help save your life. It doesnt have moods or feelings, if its hurting, something is wrong, fix it and move on with your treatments ...
Florea, V., Rieger, A. C., DiFede, D. L., El-Khorazaty, J., Natsumeda, M., Banerjee, M. N., Tompkins, B. A., Khan, A., Schulman, I. H., Landin, A. M., Mushtaq, M., Golpanian, S., Lowery, M., Byrnes, J., Hendel, R., Cohen, M. G., Valasaki, K., Pujol, M. V., Ghersin, E., Miki, R. & 11 others, Delgado, C., Abuzeid, F., Vidro-Casiano, M., Saltzman, R. G., DaFonseca, D., Caceres, L. V., Ramdas, K. N., Mendizabal, A., Heldman, A. W., Mitrani, R. & Hare, J., Nov 10 2017, In : Circulation Research. 121, 11, p. 1279-1290 12 p.. Research output: Contribution to journal › Article ...
Rami A. Dalloul, Julie A. Long, Aleksey V. Zimin, Luqman Aslam, Kathryn Beal, Le Ann Blomberg, Pascal Bouffard, David W. Burt, Oswald Crasta, Richard P. M. A. Crooijmans, Kristal Cooper, Roger A. Coulombe, Supriyo De, Mary E. Delany, Jerry B. Dodgson, Jennifer J. Dong, Clive Evans, Karin M. Frederickson, Paul Flicek, Liliana Florea, Otto Folkerts, Martien A. M. Groenen, Tim T. Harkins, Javier Herrero, Steve Hoffmann, Hendrik-Jan Megens, Andrew Jiang, Pieter de Jong, Pete Kaiser, Heebal Kim, Kyu-Won Kim, Sungwon Kim, David Langenberger, Mi-Kyung Lee, Taeheon Lee, Shrinivasrao Mane, Guillaume Marcais, Manja Marz, Audrey P. McElroy, Thero Modise, Mikhail Nefedov, Cédric Notredame, Ian R. Paton, William S. Payne, Geo Pertea, Dennis Prickett, Daniela Puiu, Dan Qioa, Emanuele Raineri, Magali Ruffier, Steven L. Salzberg, Michael C. Schatz, Chantel Scheuring, Carl J. Schmidt, Steven Schroeder, Stephen M. J. Searle, Edward J. Smith, Jacqueline Smith, Tad S. Sonstegard, Peter F. Stadler, Hakim Tafer, ...
Publications in 1998 (The underlined authors are from the Institute.) Barrow, P. A., Lovell, M. A., Szmolleny, G., and Murphy, C. K. (1998): Effect of enrofloxacin administration on excretion of Salmonella enteritidis by experimentally infected chickens and on quinolone resistance of their Esherichia coli florea. Avian Pathology 27. 586-590.
Publications in 1998 (The underlined authors are from the Institute.) Barrow, P. A., Lovell, M. A., Szmolleny, G., and Murphy, C. K. (1998): Effect of enrofloxacin administration on excretion of Salmonella enteritidis by experimentally infected chickens and on quinolone resistance of their Esherichia coli florea. Avian Pathology 27. 586-590.
A butterfly has three major body parts-head, thorax and abdomen. (i) Head: The head of a butterfly is spherical in shape. It bears two compound eyes placed at two sides of the head.
The basic structure of eyes that we see today was present during the Cambrian era, but there is a lot of variety. The male version of the mayfly has a large compound eye which allows it to watch the sky for the form of a female. The four-eyed fish is able to look up to the surface of the water, and also keep watch below for any danger. Human eyes are fast, but birds of prey have superior resolution.. Nilssons research has shed light on an ongoing debate about the evolution of eyes. Some scientists believed there were many origins; others suggested there was only one step in their evolution. This latter idea was based on the discovery of a gene, called Pax6, which controls the development of eyes.. They are all right. The eyes of many organisms have evolved from Nilssons first stage. All eyes begin with the same building block, a protein called an opsin. Opsins hold a chromophore which is able to take in the energy of a photon. The chromophore and the opsin set off the start of ...
Definition: superposition compound eyes where each ommatidium is equipped with a lens cylinder arrangement, producing the equivalent of a pair of lenses, with the first lens producing a small image halfway down the structure and the second lens turning the image back into a parallel beam. In the process the ray direction is reversed. Thus, the emerging beam is on the same side of the axis as the entering beam-the condition for obtaining a superposition image from the whole array ...
Life history. In October the females lay eggs usually on the stems of trees or shrubs. The eggs are black, with thick shells and can withstand extremes of temperature. It is in the egg form only that aphids pass the winter. In March the eggs hatch out into wingless female nymphs which are similar to the adults, with three pairs of legs, compound eyes, antennae, etc. There is no larval or pupal stage comparable to those of the butterfly, but with successive moults and continuous growth the nymphs become mature females. No males are hatched at all ...
When she was young, Colleen McCullough realized she would spend her old age in poverty unless she started to write. As I moved through my 20s and 30s, I became aware that I was going to be a 70-year-old spinster living in a cold-water, walk-up flat with a single 60-watt light bulb, she later...
Havent you ever told a little lie in the name of love?. Vivia Grant couldnt be happier. She has her dream job and is about to marry her dream man. Does it really matter that shes led him to believe shes a virgin? After all, being in love makes every experience feel like the first time anyway! But an unexpected encounter with an ex-lover is about to expose her embarrassing lie…. When Vivias fiancé discovers the truth, he ends their engagement-via text-and uses his connections to get her fired. Unemployed and heartbroken, Vivia begins planning her new future-as a homeless spinster. But her best friend has a better idea. Theyll skip the Ben & Jerrys binge and go on Vivias honeymoon instead. Two weeks cycling through Provence and Tuscany, with Luc de Caumont, a sexy French bike guide. Too bad Vivias not a big fan of biking. And shes abysmal at languages. Will she fib her way through the adventure, or finally learn to love herself-and Luc-flaws and all? Leah Marie Brown has a wily way ...
and i was struck with the neato microscopy images & highly specialized language & thot id make a post out of it & hopefully it wont offend any of the involved biologists & their work can be said to have poetic qualities as just about everything does but context is context & flyeyes are flyeyes. ...
Bruen, Danielle and McColgan, Adam and Delaney, Colm and Florea, Larisa and Diamond, Dermot (2016) Fluorescence Sensing for Non-Invasive and Continuous Glucose Detection. In: American Advanced Materials Congress 2016, 4th-9th Dec 2016, The Caribbean Sea.. Daikuzono, Cristiane and Florea, Larisa and Delaney, Colm and Tesfay, Henok and Morrin, Aoife and Diamond, Dermot and Novais de Oliveira Jr., Osvaldo (2016) Impedance spectroscopy for the detection of monosaccharides using functionalized carbon screen-printed electrodes on paper. In: E-MRS 2016 Fall Meeting, 19 to 22 Sept 2016., Warsaw, Poland.. Bruen, Danielle and Delaney, Colm and Florea, Larisa and Diamond, Dermot (2016) Boronic acid derivatives for indirect fluorescent glucose sensing. In: 3rd Insight Student Conference 2016, 14 Sept. 2016, Dublin City University, Dublin, Ireland.. Tudor, Alexandru and McColgan, Adam and Delaney, Colm and Florea, Larisa and Diamond, Dermot (2016) Functional ionic liquids for solvent sensing. In: The 3rd ...
Full headline: Local band Spinster to plant new roots in Colorado, reimagines musical project with Annie Oakley members Originally published by OU Daily, Sept. 15, 2019. Spinster is packing its bags. Jo Babb, the frontwoman of the indie-rock band, said after five years of performing in one group or another in the OKC metro area - its time for her to move on. Babb plans to move to Fort Collins, Colorado, in November to re-imagine the musical project and continue to create music with her twin sis
Looking for online definition of ommatidia in the Medical Dictionary? ommatidia explanation free. What is ommatidia? Meaning of ommatidia medical term. What does ommatidia mean?
The name Triops comes from the Greek τρία (tría) meaning three and ὤψ (ops) meaning eye.[8] The head of T. longicaudatus bears a pair of dorsal compound eyes that lie close to each other and are nearly fused together. The compound eyes are generally sessile (not stalked). In addition, there is a naupliar ocellus (the third eye) between them. The compound eyes are on the surface of the head, but the ocellus is deep within the head. All the eyes, however, are easily visible through the shell covering of the head. Franz von Paula Schrank was the first author to use the genus name Triops,[9] coining it in his 1803 work on the fauna of Bavaria. Their German name was Dreyauge, which means three-eye. He collected and described specimens from the same locality in Regensburg from which Schäffer, another naturalist who had studied the Notostraca, obtained his specimens in the 1750s. However, other authors, starting with Louis Augustin Guillaume Bosc, had adopted the genus name Apus for ...
These remarkable eyes belong to a male St. Marks fly Bibio marci - which has not one pair of compound eyes, but two. This is the black fly that dances just above the grass on spring days, dangling its long hind legs. You can find a picture of this behaviour on Nyctaluss Stand and Stare blog. These dancing males are on the lookout for females, which they approach from below, and the conjecture is that those long, fine hairs in between each individual compound eye lens (ommatidium) somehow help in the flys detection of movement above and precise positioning when he grabs a female. ...
Panstrongylus megistus is similar to other members of the Triatominae in physical appearance. The species have hemielytra (modified forewings) and mouthparts adapted for piercing blood vessels. Their heads are forwardly directed, freely moveable, and are set on an identifiable neck. The head is flattened, though elevated on the posterior half, and has 3 sclerite sections, the clypeus and two genae. For the mouthparts, the rostrum is the modified labium that protects the stylets. The stylets consist of transformed mandibles and maxillae which assist in feeding. The compound eyes on the head are associated laterally and are usually black. There are also two smaller ocelli, or simple eyes, behind the compound eyes. The thorax consists of a pronotum, a dorsal shield-like sclerite which covers the first two-thirds of the thorax, and a scutellum, which covers the final third. The ventral sclerite is called the prosternum which is smaller than the pronotum. There are two pairs of wings: the hindwings ...
In this paper, metamorphosis of laboratory-reared cyprids of the pedunculate cirripede, Capitulum mitella was successfully induced. A timeline and a detailed description of morphological events during metamorphosis were derived from light microscopy and scanning electron microscopy analyses. The metamorphic process of cyprids involves five main events. (1) Triggering of metamorphosis: after 0-6 h of reagent exposure, the epidermis ventral to the compound eyes gradually invaginates. (2) Invagination and separation of epidermis: after 6-36 h, the invagination bypasses the compound eyes, the cypris epidermis separates slightly from the carapace and the nauplius eye gradually migrates ventrally. (3) Formation of juvenile rudiment: after 36-72 h, the metamorphosing specimen shape slightly resembles that of a juvenile. (4) Shedding of thoracopodal exuvium: after 72-96 h, the cyprid finally sheds the thoracopodal exuvium and metamorphoses into a juvenile barnacle. (5) Early development of juvenile ...
The President stared at the door as it closed behind the hapless young man who had proved to be such a disappointment. A good speech writer was invaluable to a man of his elevated stature, and he needed some time to review the speech before he had to stand in the full House of Representatives and read the speech before the joint houses of Congress. He could read off the teleprompter with a skill and ease that few people possessed, but it helped to feel at least a little comfortable with the text. He already received a bit of flack from those nasty right wing zealots over the way he looked down his nose when he spoke, but it was the only way he could read the teleprompter and keep his head up. And everybody knew those crazies on the right were just looking for something bad to say about him, but he had his revenge. He worked in a way to blame them in nearly every speech and, though he had done interviews with Oprah and The View, he still refused to appear on that other network. The one he ...
INFLAMMATION AND DEPRESSION Judging by my rheumie doctors reactions to my statements about yoga and other forms of exercise, diet, and stress management, he would be against or know nothing about any article in this issue of Arthritis Today magazine. Studies have reported a general link between inflammation and depression. Johns Hopkins University researchers reported in…
Animals relying on a celestial compass for spatial orientation may use the position of the sun, the chromatic or intensity gradient of the sky, the polarization pattern of the sky, or a combination of these cues as compass signals. Behavioral experim
In some specimens, sternum 9, 10 and 11 colorless. Egg oval ( Fig. 3DView FIGURES 3), 0.375 x 0.225 mm. Description of nymph. General color varying from dark yellow to brown. Head brown, but lighter around eyes, frontoclypeal and near posterior ocelli; presence of two small lighter spots above a conspicuous M-line; compound eyes black; below eyes a dendritic brown spot; three ocelli black, the third being smaller; post-frontal line not exceeding the paired ocelli ( Fig. 4AView FIGURES 4). Antennae yellow to dark yellow. Clypeus yellow to brown. Labrum dark yellow; maxillae varying from brown to dark yellow with lacinia dark yellow and galea yellow; mandible yellow to dark brown, 5 pointed teeth on distal margin, mostly decreasing in size toward base, but teeth 2 and 4 similar in size ( Figs. 5A, 5B and 5CView FIGURES 5). Pronotum rectangular, lateral band in some specimens larger ( Fig. 4AView FIGURES 4). Pronotum, mesonotum, and metanotum varying from dark yellow to brown, with light spots ...
Hare, J., DiFede, D. L., Rieger, A. C., Florea, V., Landin, A. M., El-Khorazaty, J., Khan, A., Mushtaq, M., Lowery, M., Byrnes, J., Hendel, R., Cohen, M. G., Alfonso, C. E., Valasaki, K., Pujol, M. V., Golpanian, S., Ghersin, E., Fishman, J., Pattany, P., Gomes, S. A. & 12 others, Delgado, C., Miki, R., Abuzeid, F., Vidro-Casiano, M., Premer, C., Medina, A., Porras, V., Hatzistergos, K. E., Anderson, E., Mendizabal, A., Mitrani, R. & Heldman, A. W., Feb 7 2017, In : Journal of the American College of Cardiology. 69, 5, p. 526-537 12 p.. Research output: Contribution to journal › Article ...
(BEDFORD) - The North Lawrence Community Schools reduced internet costs by more than $40,000 with the new eRate/WAN contract. This saving is attributed to fewer facilities needing internet services within the corporation due to consolidation. The original contract was more than $80,000. In other ...
In the compound eyes of the fruitflyDrosophila, the dioptric system of each ommatidium is able to form virtual images of the receptor terminals (rhabdomere
Midge head. Coloured scanning electron micrograph (SEM) of part of the head of a midge, showing an antenna (yellow, lower right) and a compound eye (purple, top). The eye is formed from numerous lens structures known as ommatidia. Midges are tiny flies that feed on the blood of animals by inserting a needle-like proboscis (not seen). Magnification: x350 when printed 10 centimetres wide. - Stock Image C001/1838
Britain has talent, but millions of Brits decided Susan Boyle, the ample Scottish spinster, didnt have the most. Boyle was bested by the 11-person street dance group Diversity, which performed a high-energy dance number that got the crowd and the country roaring.
Mary Jocelyns life is not what one would call exciting by any standard. In The Rectors Daughter by F.M. Mayor, Mary lives a quiet country life caring for her disabled sister and aging father, the county rector. Canon Jocelyn was a handsome man in his day, not to mention brilliant, and still retains vestiges of his younger appearance and every shred of his mental faculties. Mary, on the other hand, has always been plain. As a middle-aged spinster, this is more true than ever. She did inherit her fathers intelligence, but could not sharpen her wits to the same degree because of the lack of an established womens education system. Still, her smarts are enough to set her up as a oddity to the villagers surrounding her. Her father is by no means an affectionate man and her mother died when she was very young - as a result, Marys always been alone. However, shes never really minded solitude. She passes her days in a kind of empty contentment, and shes perfectly fine with it. All of that changes, ...
U.S.A. Spinster/Aunt Lute, 1986. Paperback. Very Good. Item #166884 ISBN: 093321622X 093321622X Thumbed with small creasing to cover, minor crease to spine, name to first page, else tight and clean.
He married Stella Jolliffe on 31 January 1929 in All Saints Church, Canowindra, AustraliaG. The consent of both fathers was obtained. Charles Taylor Fleming was a Shire Clerk while James Jolliffe was a Contractor. The groom, a Bachelor Bank Clerk, was aged 20 from Orange and the bride, a Spinster Clerk, was 18 and lived at Cowra.1,2 He and Stella Jolliffe were divorced circa 1943. He married Winifred Hanigan on 23 October 1948 in Sydney, AustraliaG.2 ...
Ocelli Cream/Charcoal är en av många tyger från Sanderson ur kollektionen Madison Prints som finns att köpa på Tapetorama - Mängdrabatter - Personlig service - Beställ prover
The compound eyes probably evolved independently of arthropods' eyes. Some tube-worms use ocelli widely spread over their ... that detect the direction from which light is coming and camera eyes or compound eyes that can probably form images. ... However, the genes that drive segmentation in arthropods do not appear to do the same in annelids. Arthropods and annelids both ... ISBN 978-0-19-551368-4. Cutler, B. (August 1980). "Arthropod cuticle features and arthropod monophyly". Cellular and Molecular ...
"Molecular phylogenetic evidence for the independent evolutionary origin of an arthropod compound eye". Proceedings of the ... This eye is unable to form a proper image but is able to detect differences in the intensity of light. Azygocypridina lowryi is ... Another unusual feature of this ostracod is the possession of a lateral eye which takes the form of a hairy flap of skin ...
The parietal eye present in some amphibians and reptiles. The ocelli that occur in many arthropods. A compound eye with three ... Third eye (disambiguation) Binocular vision Monocular vision This disambiguation page lists articles associated with the title ... Trinocular vision may refer to: Animals with a rudimentary third eye: ...
The compound eyes probably evolved independently of arthropods' eyes.[20] Some tube-worms use ocelli widely spread over their ... "little eyes") that detect the direction from which light is coming and camera eyes or compound eyes that can probably form ... However, the genes that drive segmentation in arthropods do not appear to do the same in annelids. Arthropods and annelids both ... on the other hand arthropods' cuticles are made of the more rigid α-chitin,[7][21] and molt until the arthropods reach their ...
Nothomyrmecia workers feed on nectar and arthropods, using their compound eyes for prey and navigational purposes. Owing to ... Both ants have large compound eyes, relying on their vision for prey and navigational purposes. Due to their primitive and ... Prionomyrmex may have foraged on the ground or onto trees and low vegetation, feeding on nectar and arthropods. Nothomyrmecia ...
The head was short with sessile compound eyes. The back was rounded. Like Paleomerus, Strabops possessed prominent dorsal eyes ... and the position of the eyes. As the other strabopids, Strabops was a small-sized arthropod, measuring only 11 centimetres (4.3 ... Two spots between the eyes indicate the presence of the ocelli (light-sensitive simple eyes). In its abdomen, there were eleven ... The eyes were located in the middle of the front of the prosoma. These were medium-sized, ovate and narrow, and pointed ...
Many arthropods have well-developed sensory organs, including compound eyes for vision and antennae for olfaction and pheromone ... Arthropods, such as insects and crustaceans, have a nervous system made up of a series of ganglia, connected by a ventral nerve ... include arthropods, molluscs, and numerous types of worms. There is a basic difference between the two groups in the placement ...
Many arthropods have well-developed sensory organs, including compound eyes for vision and antennae for olfaction and pheromone ... Arthropods, such as insects and crustaceans, have a nervous system made up of a series of ganglia, connected by a ventral nerve ... The initial sensory response, in the retina of the eye, and the final motor response, in the oculomotor nuclei of the brain ... In the visual system, for example, sensory receptors in the retina of the eye are only individually capable of detecting " ...
... arthropodized frontal appendages and stalked compound eyes. The multisegmented limbs of fuxianhuiid may represent intermediate ... crown-group arthropods). Their positions within arthropod stem-group are indicated by numerous arthropod groundplans and ... via dinocaridids to arthropods, would lead to an arthropod body plan. Aysheaia's surface ornamentation, if homologous with ... were originally thought to be associated within the arthropod stem-group based on its apparently arthropod-like (arthropodized ...
The compound eyes of arthropods like insects, crustaceans and millipedes are composed of units called ommatidia (singular: ... Pseudopupil Arthropod eye Apposition eye Superposition eye Müller CH, Sombke A, Rosenberg J (December 2007). "The fine ... The butterfly compound eye consists of multiple eye units, or ommatidia. Each ommatidium consists of nine photoreceptor cells ( ... the Drosophila compound eye is a simple repetitive pattern of 700 to 750 of ommatidia, initiated in the larval eye imaginal ...
dachshund (dac) is a gene involved in the development of the arthropod compound eye which also plays a role in leg development ... Gehring WJ, Ikeo K (September 1999). "Pax 6: mastering eye morphogenesis and eye evolution". Trends in Genetics. 15 (9): 371-7 ... "dachshund encodes a nuclear protein required for normal eye and leg development in Drosophila". Development. 120 (12): 3473-86 ...
A large compound eye with monochromatic vision is found on each side of the prosoma;[note 1][17] it has five simple eyes on the ... Harzsch, S.; Hafner, G. (2006). "Evolution of eye development in arthropods: phylogenetic aspects". Arthropod Structure & ... Each compound eye is composed of about 1000 receptors called ommatidia,[15] complex structures consisting of upwards of 300 ... The retinula (literally, "small retina") cells of the ommatidium of the compound eye contain areas from which membranous ...
Compound eyes are common in arthropods, annelids and some bivalved molluscs. Compound eyes in arthropods grow at their margins ... The resulting eye is a mixture of a simple eye within a compound eye. Another version is a compound eye often referred to as " ... Compound eyes are very sensitive to motion. Some arthropods, including many Strepsiptera, have compound eyes of only a few ... eye) (night vision) Emission theory (vision) Eye color Eye development Eye disease Eye injury Eye movement Eyelid Nictitating ...
... the eyes of Phacops are compounded of very large, separately set lenses without a common cornea (so called schizochroal eyes), ... Arthropods portal Palaeontology portal Paleozoic portal Media related to Phacops at Wikimedia Commons. ... "Discovery of some 400 million year-old sensory structures in the compound eyes of trilobites". Scientific Reports. 3 (1429): ... It was a rounded animal, with a globose head and large eyes, and probably fed on detritus. Phacops is often found rolled up (" ...
The prosoma (head) was subtriangular, with small compound eyes at the front. The chelicerae (claws in front of the mouth) were ... Carcinosomatidae is a family of extinct arthropods in the class Eurypterida. These eurypterids are found from the Silurian to ...
Arthropod eye Parietal eye Sensory organs of gastropods Simple eye in invertebrates Vision in fish Visual system Serb, J. M.; ... to the pinhole eyes of the Nautilus, to the lensed eyes of the other cephalopods. Compound eyes are present in some bivalves, ... Chitons have a dispersed network of tiny eyes over the surface of their shells which may act together as a compound eye. Many ... There are between seven and eleven distinct eye types in molluscs. Molluscs have eyes of all levels of complexity, from the pit ...
... and compound eye specification in Drosophila" (PDF). Arthropod Structure & Development. 35 (4): 357-78. doi:10.1016/j.asd. ... just above the compound eyes). If orthodenticle is not expressed, structures from the lateral subdomain will be expressed all ... It defines the midline of the head, and is involved in the formation of the top side of the head, including the eyes. The gene ... "Ancient mechanisms of visual sense organ development based on comparison of the gene networks controlling larval eye, ocellus, ...
... a short head with sessile compound eyes and a rounded back. Like Strabops, Paleomerus possessed prominent dorsal eyes, however ... The arthropod body is divided into two tagmata (sections); the frontal prosoma (head) and posterior opisthosoma (abdomen). The ... The compound eyes appear as anterolateral reniform (bean-shaped) elevations in the surface of the prosoma. The opisthosoma ... The eyes were placed anterolaterally and rose slightly from the surface of the prosoma, with the left eye being the only one ...
The compound eyes are simpler in structure than those of other arthropods, with the individual ommatidia not being arranged in ... Xiphosurans have up to four eyes, located in the carapace. Two compound eyes are on the side of the prosoma, with one or two ... A Textbook of Arthropod Anatomy. Hafner Publishing Company, New York. Peripatus - an overview of arthropod relationships. ... The brain is relatively large, and, as in many arthropods, surrounds the oesophagus. In both sexes, the single gonad lies next ...
... and compound eye specification in Drosophila". Arthropod Structure & Development. 35 (4): 357-378. doi:10.1016/j.asd.2006.08. ... Arthropod eye Evolution of the eye Eyespot apparatus Mollusc eye Parietal eye Ocelloid "Catalog - Mendeley". ... In this sense "simple eye" is distinct from a multi-lensed "compound eye", and is not necessarily at all simple in the usual ... Spiders do not have compound eyes, but instead have several pairs of simple eyes with each pair adapted for a specific task or ...
The scapes are very short at 0.57 millimetres (0.022 in). The compound eyes are very long and convex, situated on the middle ... The clypeus (one of the sclerites that make up the "face" of an arthropod or insect) is broad and convex and the ocelli ( ... Further fossil evidence, along with its slender body and large compound eyes, suggest that they were epigaeic, foraging ... It has large eyes and the face has two pairs of long setae along with smaller setae. The scape is short and is around the same ...
The primary method for determining visual acuity in arthropods is by determining the number of lenses in their compound eyes ... as suggested by the low IOA and many lenses in their compound eyes. Further studies on the compound eyes of fossilised ... The unique eyes of modern horseshoe crabs are highly distinct from eyes of other modern arthropods and allow increased edge- ... The chelicerae and compound eyes of Jaekelopterus indicate it was active and powerful with high visual acuity, most likely an ...
The head also bears the (usually stalked) compound eyes. Because lobsters live in murky environments at the bottom of the ocean ... Like most arthropods, lobsters must moult to grow, which leaves them vulnerable. During the moulting process, several species ... The lobster eye has a reflective structure above a convex retina. In contrast, most complex eyes use refractive ray ... Land MF (1976). "Superposition images are formed by reflection in the eyes of some oceanic decapod Crustacea". Nature. 263 ( ...
The primary method for determining visual acuity in arthropods is by determining the number of lenses in their compound eyes ... with compound eyes located near the edge of the front corners. The telson (the posteriormost segment of its body) has a ... which researchers could determine by observing a low IOA and a large number of lenses in their compound eyes. The chelicerae of ... The outline and position of the eyes suggest an assignation to the genus Pterygotus, differing from P. monroensis in being ...
The large compound eyes are at the sides of the head. Members of the family Inocelliidae have no simple eyes; members of the ... Here they feed on the eggs and larvae of other arthropods such as mites, springtails, spiders, barklice, sternorrhynchids and ... Insects reared at constant temperatures in a laboratory may become "prothetelous", developing the compound eyes and wingpads of ... Both adults and larvae are predators of soft-bodied arthropods. Adult snakeflies are easily distinguished from similar insects ...
The fly has compound eyes made up of ocelli and is found in New Zealand. "Prosopochaeta anomala Aldrich 1934 - Encyclopedia of ... Koenemann, Stefan; Jenner, Ronald (2005-04-27). Crustacea and Arthropod Relationships. CRC Press. ISBN 978-1-4200-3754-8. " ...
... organised in a way that resembles a true compound eye, a type of eye found in arthropods. Most myriapods bear stemmata - that ... single lensed eyes which evolved by the reduction of a compound eye. However, the genus Scutigera has secondarily re-evolved a ... Member of the genus have pseudofaceted eyes. This type of eye consists of a cluster of numerous ocelli on each side of the head ... compound eye composed of repeated stemmata. These appear to grow in rows which are inserted between existing rows of ocelli. ...
This interpretation is supported by numerous arthropod-like features found on radiodonts, such as compound eyes, digestive ... "Arthropod eyes: The early Cambrian fossil record and divergent evolution of visual systems". Arthropod Structure & Development ... The head bore two stalked compound eyes, which may have mobility, and located between the gaps forming by the posterior regions ... Nerves of frontal appendages and compound eyes arose from the anterior and lateral regions of the brain, respectively. ...
... proving that Anomalocaris was indeed an arthropod as had been suspected. The find also indicated that advanced arthropod eyes ... In 2011, six fossils of compound eyes, the first for Anomalocaris, were recovered from a paleontological dig at Emu Bay on ... The P-elements were previously misinterpreted as two huge compound eyes. Anomalocaris canadensis possessed 14 segments ( ... the eyes of Anomalocaris were 30 times more powerful than those of trilobites, long thought to have had the most advanced eyes ...
In 2011, seven fossils of large, isolated compound eyes were described from the inland quarry site at Emu Bay, as well as the ... The find also indicated that advanced arthropod eyes had evolved very early, before the evolution of jointed legs or hardened ... The eyes were 30 times more powerful than those of trilobites, long thought to have had the most advanced eyes of any species ... "Cambrian predator had killer eyes". ABC Science. Retrieved 15 February 2012. Fossilised eyes of ancient super-predator found ...
This eye is derived from the primary naupliar eye.[6] Life cycle[edit]. Barnacles have two distinct larval stages, the nauplius ... A barnacle is a type of arthropod constituting the infraclass Cirripedia in the subphylum Crustacea, and is hence related to ... It cements itself permanently to the substrate with another proteinaceous compound, and then undergoes metamorphosis into a ... A fertilised egg hatches into a nauplius: a one-eyed larva comprising a head and a telson, without a thorax or abdomen. This ...
The Roving Eye Meets Traveling Pictures: The Field of Vision and the Global Rise of Adult Manga. Comics As a Nexus of Cultures ... The scientific Latin term octopus was derived from Ancient Greek ὀκτώπους or ὀκτά-, a compound form of ὀκτώ (oktō, "eight") and ... They feed on copepods, arthropod larvae and other zooplankton, eventually settling on the ocean floor and developing directly ... The eyes of the octopus are large and are at the top of the head. They are similar in structure to those of a fish and are ...
The rash may look like a "bull's eye", as pictured, in about 80% of cases in Europe and 20% of cases in the US.[23][24][25][26] ... "Protection against Mosquitoes, Ticks, & Other Arthropods". Travelers' Health. Centers for Disease Control and Prevention. ... a natural compound) and OLE's active ingredient para-menthane-diol (PMD).[128][137][138] Unlike permethrin, repellents repel ... Edlow, Jonathan A (2003). Bull's-eye: unraveling the medical mystery of Lyme disease. Yale University Press. ISBN 978-0-300- ...
Eye * sw:Eye. Family * sw:Family. Fascism * sw:Fascism. Fashion * sw:Fashion. Federico Fellini * sw:Federico Fellini. Feminism ... Arthropod * sw:Arthropod. Artificial intelligence * sw:Akili bandia. ASEAN * sw:ASEAN. Ashoka * sw:Ashoka. Asia * sw:Asia. ... Chemical compound * sw:Chemical compound. Chemical element * sw:Chemical element. Chemistry * sw:Chemistry. Chess * sw:Chess. ...
... "eye-blaze", where the pupil of the eye constricts to reveal the edge of the iris.[52] Allopreening is used by the pair to help ... The diet of parrots consists of seeds, fruit, nectar, pollen, buds, and sometimes arthropods and other animal prey. The most ... Many species in the Americas, Africa, and Papua New Guinea consume clay, which releases minerals and absorbs toxic compounds ... The head is large, with eyes positioned high and laterally in the skull, so the visual field of parrots is unlike any other ...
Drones have large eyes used to locate queens during mating flights. They do not defend the hive or kill intruders, and do not ... compounds gradually solidify in the orthography of natural languages in ways that do not always comply with prescription. ...
Eyes. Tears[2] Blood-brain barrier. endothelial cells (via passive diffusion/ osmosis & active selection). P-glycoprotein ( ... In the hemolymph, which makes up the fluid in the circulatory system of arthropods, a gel-like fluid surrounds pathogen ... Some of these travel through the plant and signal other cells to produce defensive compounds to protect uninfected parts, e.g ... The flushing action of tears and saliva helps prevent infection of the eyes and mouth.[2] ...
... fleas do not possess compound eyes but instead only have simple eyespots with a single biconvex lens; some species lack eyes ... The larvae are small and pale, have bristles covering their worm-like bodies, lack eyes, and have mouth parts adapted to ...
The smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules ... Individual zooplankton are usually microscopic, but some (such as jellyfish) are larger and visible to the naked eye.. ... and arthropods.. insulin. An anabolic peptide hormone produced in the pancreas which helps to regulate the metabolism of ... An organic compound with chemical formula CO(NH2)2.. urine. A liquid byproduct of metabolism in humans and in many animals.. ...
4. compound eye. 5. brain (cerebral ganglia). 6. prothorax. 7. dorsal blood vessel. 8. tracheal tubes (trunk with spiracle). 9 ... Arachnids are arthropods that have four pairs of legs. Centipedes are also arthropods, but not insects: they are in a subphylum ... On the head are an insect's compound eyes, its two antennae (they feel and smell things), and its mouth. ... Erwin, Terry L. (1982). "Tropical forests: their richness in Coleoptera and other arthropod species". Coleopt. Bull. 36: 74-75. ...
... and of further integration of a compound eye into a simple eye.[15] In contrast, lateral eyes are absent in many species, and ... Holm, Erik; Dippenaar-Schoeman, Ansie (2010). Goggo Guide: The arthropods of southern Africa. Pretoria: LAPA Publishers. ISBN ... Some species have very large central eyes. They look like simple eyes or ocelli, but are surprisingly sophisticated. They can ... they may represent the last step in the integration of the aggregate of simple ocelli into a compound eye, ...
In: Roques et al. (Eds). Alien terrestrial arthropods of Europe". BIORISK - Biodiversity and Ecosystem Risk Assessment. 4: 97- ... The common name "millipede" is a compound word formed from the Latin roots mille ("thousand") and ped ("foot"). The term " ... Hudson, B.; Parsons, G. (1997). "Giant millipede 'burns' and the eye". Transactions of the Royal Society of Tropical Medicine ... "Arthropod Structure & Development. 39 (2-3): 174-190. doi:10.1016/j.asd.2009.11.002. PMID 19944188.. ...
Arthropod[edit]. Evidence supports its use against parasitic arthropods and insects: *Mites such as scabies:[25][26][27] It is ... Common side effects include red eyes, dry skin, and burning skin.[1] It is unclear if it is safe for use during pregnancy, but ... The discovery of the avermectin family of compounds, from which ivermectin is chemically derived, was made by Satoshi Ōmura of ... "Ivermectin for onchocercal eye disease (river blindness)". The Cochrane Database of Systematic Reviews. 8 (8): CD002219. doi: ...
The pair of large compound eyes almost touch in the male, but are more widely separated in the female. They have three simple ... "Bizarre interactions and endgames: entomopathogenic fungi and their arthropod hosts" (PDF). Annual Review of Entomology. 51 ... Head of a female housefly with two large compound eyes and three ocelli ... They have red eyes, set farther apart in the slightly larger female. ...
As with fungicides, the first insecticides used in the nineteenth century were inorganic e.g. Paris Green and other compounds ... These changes can manifest in the alteration of metabolism of endemic microorganisms and arthropods resident in a given soil ... There is an entire spectrum of further health effects such as headache, nausea, fatigue, eye irritation and skin rash for the ...
Sensory organs include compound eyes (often stalked), ocelli (simple eyes), statocysts and sensory bristles. The naupliar eye ... He was curator of the arthropod collection at the National Museum of Natural History in Paris.[1] The name comes from the Greek ... Usually a pair of stalked compound eyes is present, although in some taxa the eyes are unstalked, reduced or lost.[9][10] ... Little, Colin (1983). "Crustaceans and the evolution of the arthropods". The Colonisation of Land: Origins and Adaptations of ...
Template:Eye navs(edit talk links history). *Template:Fungus navs(edit talk links history) ...
Arthropods such as ticks, mites, fleas, and lice, can also cause human disease, which conceptually are similar to infections, ... They can be local at times as in viral conjunctivitis or "pink eye" and herpes. Only a few viral infections are painful, like ... Microscopy may be carried out with simple instruments, such as the compound light microscope, or with instruments as complex as ... eyes, genitalia, anus, or the microbe can enter through open wounds. While a few organisms can grow at the initial site of ...
Eyes. *Arthropod eye. *Compound eye. *Eagle eye. *Eye shine. *Simple eye in invertebrates ... The lack of saccadic eye movements forces the toad to hold its eyes in rigid positions. Therefore, it must decide whether the ... R, retina (contralateral eye); O, optic tectum; Pt, pretectal thalamus; Lt, lateral anterior thalamic nucleus; At, anterior ... One reason for this type of stimulus-response chain is that, unlike humans, toads do not have involuntary saccadic eye ...
Some cave crustacea reproduce more successfully with smaller eyes than do those with larger eyes. This may be because the ... Over the last 50 years it has become resistant to 52 chemical compounds used in insecticides, including cyanide.[56] This is ... The colour of eyes is entirely inherited; they are a genetic trait. Height or weight is only partly inherited, and the language ... One of the most widespread adaptations in animals is the evolution of the eye. Another example is the adaptation of horses' ...
The eyes may include simple eyes or ocelli as well as compound eyes of varying sizes. Many species are able to detect light in ... Insects or Insecta (from Latin insectum) are hexapod invertebrates and the largest group within the arthropod phylum. ... a pair of compound eyes, zero to three simple eyes (or ocelli) and three sets of variously modified appendages that form the ... 4. compound eye. 5. brain (cerebral ganglia). 6. prothorax. 7. dorsal blood vessel. 8. tracheal tubes (trunk with spiracle). 9 ...
Large compound eyes, sensitive antennae, and powerful jaws (mandibles) of jack jumper ant ... wolf spiders and all the thousands of species of solitary wasps among arthropods,[68][69] and many microorganisms and ... large compound eyes and jaws made of a hard material like that in the exoskeleton of an insect.[171] Some of the first fish to ... Many butterflies and moths have eyespots, wing markings that resemble eyes.[123] When a predator disturbs the insect, it ...
... have one pair of principal eyes and three pairs of secondary eyes located on the prosoma (the anterior end of ... The venom contains at least 286 compound and 49 novel proteins.[12] In addition, there are many low molecular compounds, nine ... i5k Insect and other Arthropod Genome Sequencing Initiative. *Photograph. *Photograph at fineartamerica ... Cupiennius salei produces a neurotoxic venom which is composed of a complex mixture of compounds. ...
Blind skinks are insectivorous and feed on arthropods and earthworms.[3] Blind skinks are characterized by their fossorial or ... the coronoid and the compound bone.[2] A remnant of the splenial bone is only present in one species of Dibamus, Dibamus ... and highly reduced eyes that lack internal structure and are covered by a scale and lack internal structure, particularly in ...
... and even anchoring the arthropod to a substrate.[2] Larval arthropods have antennae that differ from those of the adult. Many ... The large flattened plates in front of the eyes of a slipper lobster are the modified second antennae. ... Giant swallowtail butterflies also rely on antenna sensitivity to volatile compounds to identify host plants. It was found that ... Boxshall, G.A. (2004). "The evolution of arthropod limbs". Biological Reviews of the Cambridge Philosophical Society. 79 (2): ...
Workers possess single-faceted compound eyes, double-segmented waists, a well-developed sting, and specialized tarsal hooks on ... Insects and other arthropods attempting to escape from E. burchellii are flushed into the attending flocks, and a number of ... When the ant colony swarms the forest leaf litter, arthropods flee, which are then eaten by the birds, lizards, insects, and ... This imposes a selective pressure on the colonies, as the arthropods collected from these raids represent nearly half of the ...
It had a small antorbital fenestra, the hole between the nose and eye common to most archosaurs, including modern birds, though ... or reservoir of compounds to support the nervous system.[67] ... Arthropods in film. *Crab. *Lobster. *Scorpion. *Spider * ...
Bruise/Hematoma/Ecchymosis (Battle's sign, Raccoon eyes, Black eye, Subungual hematoma, Cullen's sign, Grey Turner's sign, ... Arthropod bites and stings. *bee sting / bee venom *Apamin. *Melittin. *scorpion venom *Charybdotoxin ...
Topic: Compound eyes in arthropods. Categories: Arthropods: Insects, Arthropods: other than Insects, Eyes & other Visual ... Compound eyes and ancestral arthropods. At a more fundamental level there is now evidence that a fully functioning compound eye ... Map of Life - "Compound eyes in arthropods". November ... Whilst compound eyes are the norm in the arthropods, and as well as in the insects and trilobites are also found in the ...
Can you name the Arthropod Morphology? Test your knowledge on this science quiz to see how you do and compare your score to ... Single cell of compound eye. First stage of life cycle. Second stage of life cycle. ...
Here we are able to show the excellently preserved internal structures of the compound eye of a 429 Mya old Silurian trilobite ... We show that this Palaeozoic trilobite in principle was equipped with a fully modern type of visual system, a compound eye ... kind of visual system commonly is considered to be the compound eye. ... Aulacopleura koninckii (Barrande, 1846). It shows the characteristic elements of a modern apposition eye, consisting of 8 ( ...
Molecular phylogenetic evidence for the independent evolutionary origin of an arthropod compound eye. Proceedings of the ... Each major group of arthropods is characterised by a particular tagmosis. Arthropods include groups that are wholly marine (the ... A cross‐section of a typical arthropod segment showing basic characteristics. All arthropods are built from many such segments ... Recent phylogenomic studies are beginning to resolve arthropod relationships. Two of the largest groups of arthropods - ...
The Compound Eye. Epithelial Physiology of Insect Sensilla. Functional Organisation of Arthropod Neuroglia. The Past and Future ... also discuss the various avenues of water loss and gain as interrelated components of overall water balance in land arthropods ...
... and with opsins that differ from those expressed in the compound eyes. Our data show that cricket eyes are spectrally more ... We assign three of these opsins to visual pigments found in the compound eyes with peak absorbances in the green (515 nm), blue ... We have therefore investigated visual opsins in the ocelli and compound eyes of the two-spotted cricket Gryllus bimaculatus, a ... The arrangement of spectral receptor types within some ommatidia of the cricket compound eyes differs from the generally ...
Arthropods (Grasshopper) - Perch Dissection Pre-AP Biology April 9, 2014 - Vu 3rd by Lucas Martins , This newsletter was ... They also have compound eyes like other insects. However, their legs and wings set them apart from others because of the ... Arthropods (Grasshopper) Perch Dissection Pre-AP Biology April 9, 2014 - Vu 3rd ... Arthropods (Grasshopper) Perch Dissection Pre-AP Biology April 9, 2014 - Vu 3rd ...
Most arthropods have at least one of two types of eye: lateral compound eyes, and smaller median ocelli, which are simple eyes ... In turn, the dispersal of compound eyes seems to have created large networks of seemingly independent eyes in some arthropods, ... Apposition eyes are the most common form of eye, and are presumably the ancestral form of compound eye. They are found in all ... Mollusc eye Parietal eye Simple eye in invertebrates Vision in fish Optic lobe (arthropods) They are about 5000 times more ...
Brigitte Schoenemann; Euan N. K. Clarkson (2020). "Insights into a 429-million-year-old compound eye". Scientific Reports. 10 ( ... A study on the anatomy of the internal structures of the compound eye of Aulacopleura koninckii is published by Schoenemann & ... Paleontology portal History of science portal This list of fossil arthropods described in 2020 is a list of new taxa of ... Abel Pérez-González; Jeffrey W. Shultz (2021). "On the problematic placement of the fossil arthropod Devonopilio hutchinsoni in ...
They had compound eyes with thin, biconvex lenses made of calcite. The last of the trilobites died out at the end of the ... The arthropods (jointed foot) are the most successful group of organisms ever. They include centipedes , insects , crustaceans ... They had compound eyes with thin, biconvex lenses made of calcite. The last of the trilobites died out at the end of the ... That span of 0.8 billion years saw a transition from elemental carbon to organic compounds and from organic compounds to ...
Adult insects have one pair of antennae, one set of mandibles, and two compound eyes. Their compound eyes are often so large as ... The crustaceans eyes are compound, which means that each one contains many small lenses.. Crustaceans make up an extremely ... Groups of Arthropods. The arthropods are often classified, or divided, into four distinct groups, or subphyla. They are ... Arthropod Evolution. Many biologists suspect that the arthropods evolved from the annelids, a phylum of segmented worms that ...
... arthropod compound eye."4 And clams from the family Arcidae use compound eyes. Other than their compound eyes, worms, sea stars ... Arthropods illustrate both observations. The classic and unique arthropod compound eye works effectively, as anyone who has ... the ancestor of all arthropods should have passed its compound eye design on to its descendants. But some arthropods use ... However, some worms have compound eyes. They also illustrate the second observation, that different animals share similar eye ...
Oakley, T. H. (2003). On homology of arthropod compound eyes. Integr. Comp. Biol. 43,522 -530. ... Many animals stabilize their vision by swivelling their eyes to prevent the image from smearing as they move. A new Research ... suggesting that the eye may be processing the image at a basic level to produce the reflex. ...
compound eye photoreceptor cell differentiation Source: FlyBaseTraceable author statementi*. "Coming to our senses.". Treisman ... "The evolution of arthropod segmentation mechanisms.". Peel A.. Bioessays 26:1108-1116(2004) [PubMed] [Europe PMC] [Abstract] ... compound eye morphogenesis Source: FlyBaseInferred from mutant phenotypei*. "Roadkill attenuates Hedgehog responses through ... progression of morphogenetic furrow involved in compound eye morphogenesis Source: FlyBaseInferred from mutant phenotypei*. " ...
The compound eyes probably evolved independently of arthropods eyes.[20] Some tube-worms use ocelli widely spread over their ... "little eyes") that detect the direction from which light is coming and camera eyes or compound eyes that can probably form ... However, the genes that drive segmentation in arthropods do not appear to do the same in annelids. Arthropods and annelids both ... on the other hand arthropods cuticles are made of the more rigid α-chitin,[7][21] and molt until the arthropods reach their ...
Meyer-Rochow, V. B. and Nilsson, H. L. (1998). Compound eyes in polar regions, caves and the deep-sea. In Atlas of Arthropod ... Compound eye designs. (A) A focal apposition compound eye. Light reaches the photoreceptors exclusively from the small corneal ... This would require that the ocelli and/or the compound eyes are sensitive to polarised light. The dorsal areas of compound eyes ... This eye design is typical of day-active insects. (B) A refracting superposition compound eye. A large number of corneal facets ...
In arthropods, the size, shape, color, ommatidium number and surface texture of the compound eye influence many features of the ... The compound eyes of B. cucurbitae, B. tau and B. dorsalis were found to be ellipsoid in shape (Fig. 1). Each compound eye was ... We investigated the external morphology, eye size, facet size, and numbers of ommatidia and ommatrichia of the compound eyes of ... of the compound eyes, and the SEM images were used to obtain measurements of individual square ommatidium area per eye using a ...
Compound Eye, Arthropod / anatomy & histology * Compound Eye, Arthropod / innervation * Flight, Animal* * Odonata / physiology ... a novel synthesis of datasets and subfields that integrates many aspects of flight from the neurobiology of the compound eye, ...
Compound eye: circadian rhythmicity, illumination and obscurity. In "Atlas of arthropod sensory receptors-Dynamic morphology in ... The structure of a compound eye. The central region of the compound eye. The compound eyes of both nymphs and adults are of the ... The dorsal rim area of the compound eye. Fig. 5B shows the RORs of the DRAs of the compound eyes at midday and midnight. In ... The central region of the compound eye. Fig. 5A shows the RORs in the central region of the compound eyes between midday and ...
... adjacent neuroommatidia in the compound eye of the blowfly, Calliphora erythrocephala(Mg.), are presented. These experiments ... Kirschfeld K, Lutz B (1974) Lateral inhibition in the compound eye of the fly,Musca. Z Naturforsch 29c:95-97Google Scholar ... In: Wehner R (ed) Information processing in the visual systems of arthropods. Springer, Berlin Heidelberg New York, pp 61-74 ... Franceschini N (1975) Sampling of the visual environment by the compound eye of the fly: Fundamentals and applications. In: ...
Compound and simple. Retina. Lens. In addition to compound eyes, many arthropods also have simple eyes ("eyespots"), e.g. the ... There are at least 9 known types of layouts of the eye in organisms, divided into simple or non-compound eyes (5) and compound ... Vertebrate eyes[edit]. Diagram of the vertebrate eye (left) vs. the octopus eye (right). Number 4 indicates the location of the ... Four-eyed fish (genus Anableps). Simple. Retina. Vitreous humor (closed). Lens/cornea. It actually has two eyes but with eye ...
The Crustacea is a subphylum of arthropods defined by the nauplius larva, two pairs of antennae and biramous (two branched) ... Oakley TH (2003) On homology of arthropod compound eyes. Integrative and Comparative Biology 43: 522-530. ... Arthropod Structure and Development 39: 143-153. Koehl MAR and Strickler JR (1981) Copepod feeding currents: food capture at ... The Crustacea is a subphylum of arthropods defined by the nauplius larva, two pairs of antennae and biramous (two branched) ...
Arthropods have compound eyes; in crabs and lobsters, these eyes are placed on stalks to enhance visibility from burrows or ... What Makes an Arthropod? by Sean Chamberlin. Among animals on Earth, the arthropods are king. More than a million species, ... Cephalization in arthropods has led to spectacular adaptations for vision and sensing. Arthropods exhibit a brain (dorsal ... First, however, lets visit the body plan of arthropods and explore how the adaptations of arthropods account for their success ...
The first fossil eyes are from the Cambrian; compound eyes on arthropods. Modern insects are shown, explained as not ... They got it right when describing dragon fly eyes, but I really wish they had hammered home the point that compound eyes dont ... Theres also a nice simple animation of how an eye patch could form an eye cup, then an eye with a lens. ... So weve got the evolution of mammalian eyes, jelly fish eyes, squid eyes… ...
... paleontologists have found after discovering a fossilised eye. ... Its compound eyes put it in the arthropod family, which ... The team previously found a similar eye fossil at Emu Bay, but did not know which Arthropod it came from. ... it suggests complex eyes developed extraordinarily quickly. As Dr Paterson sums it up, "In the geological blink of an eye". ... The sea creatures eyes belong to an earlier period of the Cambrian explosion in evolutionary terms, but as there is no ...
Mohr T., Meinertzhagen I.A., Fischer S. (2019) Novel type of sub‐retinal pigment shield in the miniaturized compound eye of ... Arthropod Structure and Development (48:35-48). ...
Although compound eyes are most often associated with the arthropods, especially insects and ... Apposition eyes: Apposition eyes were almost certainly the original type of compound eye and are the oldest fossil eyes known, ... Other articles where Apposition eye is discussed: photoreception: ... Apposition eyes were almost certainly the original type of compound eye and are the oldest fossil eyes known, identified from ...
Part III: Studying the compound eye and estimating the number of facets, with notes on Leeuwenhoeks observations - completes ... A selection of arthropod images Dec.07. *Spikes Gallery IV. A selection of images of unicellular organisms - a striking ... The compound microscope - a brief introduction - auseful overview showing the main components of the compound microscope and ... Micscape Snippets 1 - On soccer balls, insect compound eyes ... and Euler Sep.15 ...
The sensory structures of insets, for example, such as the compound eyes, the tympanic membranes, and antennae can be targeted ... in Information Processing in the Visual Systems of Arthropods, Wehner, R., ed. (Berlin: Springer-Verlag., 1972). The eyes of ... The Compound Eye and Vision of Insects (Oxford: Clarendon Press, 1975), and Kirschfeld, K., "The visual system of Musca: ... Accordingly, infrared wavelengths remain transparent (non-visible) to arthropods. The arthropod cornea is constructed of ...
Centipedes are unusual among the arthropods (insects, spiders, etc.) because their exoskeletons lack the waxy coating that ... are exclusively predatory arthropods belonging to the class Chilopoda (Latin, = fang foot). ... These arthropods have lost their compound eyes, or sometimes, have no eyes at all. Soil centipedes (order Geophilomorpha) are ... These arthropods are able to survive both inside and out, but prefer to move indoors when outside temperatures become ...
  • Arthropods are the exemplar of the compound eye, most notably amongst the insects. (
  • Not only is it very likely that these two groups (chelicerates+myriapods and crustaceans+insects) have arrived independently at a compound eye construction, but intriguingly only the crustacean plus insect type is predisposed to colour vision , as well as the ability to detect polarized light. (
  • The eyes of trilobites also have a striking convergence to those found in an interesting group of insects known as the strepsipterans . (
  • The insects, of course, do not have any calcite to form the lens, but the widely spaced ommatidia are strikingly reminiscent of the arrangement of the schizochroal eye and the convergence has attracted quite a lot of attention. (
  • Whilst compound eyes are the norm in the arthropods, and as well as in the insects and trilobites are also found in the crustaceans (which are probably ancestral to the insects) and chelicerates such as the horse-shoe crab. (
  • Two of the largest groups of arthropods - crustaceans and insects - form a single clade, the Pancrustacea. (
  • They also have compound eyes like other insects. (
  • Insects and some other land arthropods breathe through a system of tiny body tubes called tracheae. (
  • Like their day-active (diurnal) relatives, these insects possess apposition compound eyes, a relatively light-insensitive eye design that is best suited to vision in bright light. (
  • In nocturnal insects, including most moths and many beetles, this eye design is typically a refracting superposition compound eye, a design that allows single photoreceptors in the retina to receive focused light from hundreds (and in some extreme cases, thousands) of corneal facet lenses ( Fig. 1B ). (
  • Not surprisingly, apposition eyes are typical of diurnal insects active in bright sunlight, and this includes all diurnal bees and wasps. (
  • The organ's development through the lineage can be estimated by comparing groups that branched early, such as the velvet worm and horseshoe crab to the advanced eye condition found in insects and other derived arthropods. (
  • Flying insects can remain level with either type of eye surgically removed, but the two types combine to give better performance. (
  • Paleontology portal History of science portal This list of fossil arthropods described in 2020 is a list of new taxa of trilobites, fossil insects, crustaceans, arachnids and other fossil arthropods of every kind that are scheduled to be described during the year 2020, as well as other significant discoveries and events related to arthropod paleontology that are scheduled to occur in the year 2020. (
  • Modern insects are shown, explained as not descendants of trilobites, but probably share the same genes Good acknowledgment of the successful utility of dragonfly eyes. (
  • In the eyes of insects that fly at night or in twilight, however, the pigment can be withdrawn so that light received from neighbouring facets overlaps to some extent. (
  • Centipedes are unusual among the arthropods (insects, spiders, etc.) because their exoskeletons lack the waxy coating that helps to retain water inside the body. (
  • Centipedes are generalist predators, preying on insects, spiders and other small arthropods. (
  • This is a collection of Terminology, Entomological and Arthropodal (See Insects or Arthropods ) in nature. (
  • More specifically my lab is interested in the eyes of two different insects: the twisted-wing insect Xenos peckii, and the larvae of the diving beetle Thermonectus marmoratus and its relatives. (
  • Buschbeck EK and M Hauser (2009) On the way to camera eyes: the visual system of male scale insects. (
  • We are all familiar with the idea that there are strikingly different kinds of eyes in animals: insects have compound eyes with multiple facets, while we vertebrates have simple lens eyes. (
  • Most centipedes are carnivorous and prey upon soft-bodied insects, spiders, worms and other arthropods, including other centipedes. (
  • either of a pair of sensory appendages on the heads of insects, crustaceans, and some other arthropods. (
  • Insects are a class of invertebrates within the arthropod phylum that have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. (
  • Insects, Crustaceans, and other Arthropods are provided with eyes having many facets, under which are grouped retinal elements surrounding a crystalline cone. (
  • Insects are a class within the arthropods that have a chitinous exoskeleton, a three-part body (head, thorax, and abdomen), three pairs of jointed legs, compound eyes, and two antennae. (
  • Other types of eye are the simple eye, found in many invertebrates, and the compound eye, found in insects and many other arthropods. (
  • Arthropods are generally classified together as a phylum (Arthropoda) of animals and include the insects , arachnids , and crustaceans , as well as millipedes and centipedes , among others. (
  • In many taxonomic schemes, the arthropods with mandibles form the clade Mandibulata, comprising the extant Myriapoda (millipedes, centipedes, and relatives), Crustacea (crustaceans, such as lobsters , crabs , and barnacles ) and Hexapoda (insects and three small groups of insect-like animals with six thoracic legs). (
  • a ) The arthropod Drosophila melanogaster belongs to a subspecies of the Drosophilidae , dipteran insects that fit on a pencil tip and can be easily kept en masse in the laboratory. (
  • Insects typically have compound eyes where each facet lens represents one pixel in their vision. (
  • Most of the many navigation tasks that insects develop rely on the visual information provided by their compound eyes. (
  • Unlike the neurophysiology of the visual pathway in the frog and the cat which is more than adequately documented, recent work on the compound eye and optical ganglia of spiders, crustaceans, and insects has scarcely been summarized. (
  • Arthropods are members of the phylum Arthropoda (from Greek ἄρθρον árthron , "joint", and ποδός podós "foot", which together mean "jointed feet"), and include the insects, arachnids, crustaceans, and others. (
  • Insects in this order have large compound eyes, and their mouthparts are adapted for licking and sucking. (
  • Insects may be found in nearly all environments, although only a small number of species occur in the oceans, a habitat dominated by another arthropod group, the crustaceans. (
  • The Compound Eye and Vision in Insects. (
  • Arthropods are known for their hard exoskeletons comprised of chitin and often reinforced with calcium carbonate , distinct body segments, distinct limb jointing and six or more limbs (with all insects having exactly six limbs). (
  • a pair of jointed appendages on the tip of the abdomen of insects and other arthropods. (
  • With more than four million species, arthropods are the largest and most diverse group of animals on the planet and include, for example, crustaceans, insects and spiders. (
  • In fact, convergent evolution of compound eyes can be recognised at two different levels: within the crustaceans, and between the major arthropod phyla, as decribed below. (
  • Give that the crustaceans almost universally possess a compound eye this claim of convergence has met with some scepticism, but detailed analysis of the alternative hypothesis, that is that a compound eye has been lost multiple times, seems distinctly less likely. (
  • We show that this Palaeozoic trilobite in principle was equipped with a fully modern type of visual system, a compound eye comparable to that of living bees, dragonflies and many diurnal crustaceans. (
  • For added protection, the exoskeleton of ocean-dwelling arthropods (the crustaceans) is strengthened by the addition of the mineral calcium carbonate. (
  • While it seems certain that simple eyes arose independently several times in crustacean evolution, little is known about the evolutionary paths taken to produce the very unusual assortment of simple eye designs present in modern crustaceans. (
  • Specifically, H. Scutula had appositional compound eyes, something often seen in arthropods and crustaceans today. (
  • The arthropods are traditionally divided into four subgroups or subphyla: trilobites (all are extinct, but the fossil record indicates that they were once the dominant subgroup), chelicerates, crustaceans, and uniramians. (
  • Exactly how this ancestral arthropod gave rise to the myriad species that exist today is unclear but we know that at some point the arthropod family tree split into branches, one of which went on to become the crustaceans. (
  • the first pair of appendages of a chelicerate arthropod. (
  • Arthropods are invertebrates that are characterized by the possession of a segmented body, a pair of jointed appendages on each segment, and an exoskeleton . (
  • Here, we describe a new arthropod from the Tulip Beds locality of the Burgess Shale Formation (Cambrian, series 3, stage 5) that possesses a weakly sclerotized thorax with filamentous appendages, encased in a bivalved carapace, and a strongly sclerotized, elongate abdomen and telson. (
  • After all they are both Arthropods i.e. small creatures with exoskeletons and jointed appendages. (
  • They have certain appendages, and these appendages indicate that they would have eaten somebody else, and the eyes are specialized to support this," study researcher Brigitte Schoenemann of the University of Bonn in Germany told LiveScience. (
  • Arthropods are invertebrates with segmented bodies, exoskeletons, jointed appendages and bilateral symmetry. (
  • biramous -- Arthropod appendages that are biramous have two branches, an outer branch and an inner branch. (
  • chelicera -- The first pair of appendages of a chelicerate arthropod. (
  • An arthropod is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages. (
  • The arthropod body plan consists of repeated segments, each with a pair of appendages. (
  • Since exocuticle is absent from joints, arthropods can move appendages and flex one body segment on another. (
  • Most arthropods use their appendages for movement, for example, as paddles in aquatic species or as legs in terrestrial ones. (
  • Antennae in biology have historically been paired appendages used for sensing in arthropods. (
  • The extreme diversity observed in Phylum Arthropoda can be attributed to three main arthropod characteristics that have evolved into various forms to allow for adaptation to different environments: a hard chitinous exoskeleton, body segmentation, and jointed appendages. (
  • This figure illustrates the body segmentation (cephalothorax and abdomen) and specialized appendages of a representative arthropod, a lobster (a crustacea). (
  • Arthropods are characterised by a segmented, jointed and hardened exoskeleton that has internal musculature. (
  • Like other arthropods, an insect has a hard outer covering, or exoskeleton, a segmented body, and jointed legs. (
  • the pupa does not eat and usually does not move, but within the exoskeleton a major transformation occurs that involves the reorganization of organ systems as well as the development of such adult external structures as wings and compound eyes. (
  • Like all arthropods, millipedes lack an internal skeleton, and instead are protected by a tough outer shell called an exoskeleton or cuticla , made of several layers. (
  • Arthropods are distinguished by a cuticular exoskeleton, secreted by an underlying layer of epidermal cells. (
  • Young arthropods grow by periodically shedding and replacing their exoskeleton (molting), a process controlled by hormones (principally ecdysterone). (
  • This exoskeleton endows arthropods with several adaptive features to the terrestrial environment. (
  • The only cumbersome feature of the exoskeleton is that it confines growth, but arthropods deal with this problem by periodically shedding their exoskeletons in a process known as molting . (
  • The extinct trilobites were equipped with eyes composed of calcite. (
  • Trilobites are extinct marine arthropods that dominated the ecosystems of the Palaeozoic. (
  • Apposition eyes were almost certainly the original type of compound eye and are the oldest fossil eyes known, identified from the trilobites of the Cambrian Period. (
  • Trilobites were one of the most successful marine arthropods that lived from the Early Cambrian throughout the Devonian , finally going extinct in the Permian ages, a run of over 270 million years. (
  • cephalon -- In trilobites , the head shield bearing the eyes, antennae, and mouth. (
  • Trilobites were an exclusively marine group of arthropods that appeared in the Cambrian Period and persisted throughout the Paleozoic, eventually becoming eztinct in the Permian Period. (
  • Yet, all vertebrate eyes share the same ground plan and differ in more fundamental ways from the eyes of invertebrates. (
  • Their prey includes a variety of arthropods and other invertebrates, and the larger species are known to prey on small vertebrates. (
  • 1. A simple eye, found in many invertebrates, consisting of a number of sensory cells and often a single lens. (
  • 1. the simple eye of many invertebrates, consisting of retinal cells, pigments, and nerve fibers. (
  • 1. A small, simple eye or eyespot, found in many invertebrates. (
  • Arthropods (from the Greek árthron , meaning joint, and podos, meaning leg or foot), are the most diverse phylum of invertebrates, consisting of an estimated 80% or so of all animal species. (
  • hardened or membranous protective layer covering the body of many invertebrates especially arthropods. (
  • This xiphosuran chelicerate shows many typical arthropod features both externally and internally, (c) comparison of the structure of the arthropod brain, for example, that of L. polyphemus and a crustacean and (d) might suggest that the chelicerae of the former are homologous to the second antennae of the latter, but this is far from clear. (
  • The Crustacea is a subphylum of arthropods defined by the nauplius larva, two pairs of antennae and biramous ('two branched') second antennae. (
  • The head bears three pairs of mouthparts, one pair of compound eyes, three simple eyes (ocelli), and one pair of jointed sensory antennae. (
  • They are also characterized by the presence of one or two pairs of antennae and have groups of eight cells in the retinula of the compound eye (if one exists). (
  • S. coleoptrata has developed automimicry in that its hind legs present the appearance of antennae, and there are false eyes on its rump. (
  • On closer inspection the mite has no antennae, no wings, 4 pairs of legs, an unsegmented abdomen, and simple eyes. (
  • Whereas an insect such as a bee will have 3 body parts, 2 compound eyes, 2 antennae, 4 wings, 3 pairs legs, and a segmented abdomen. (
  • Taxons under Insecta also have a pair of antennae, compound eyes, two pairs of wings, three pairs of legs, complex mouth parts and take part in metamorphosis. (
  • However, especially amongst the spiders the appropriately named ogre-faced spiders (or dinopids) have evolved a camera-like eye. (
  • Octopus, squid and spiders have eyes that superficially resemble those of vertebrates, but their internal structure, molecular signature, and the way they develop are so different that independent origins appear obvious. (
  • Their vision relies on various combinations of compound eyes and pigment-pit ocelli: in most species the ocelli can only detect the direction from which light is coming, and the compound eyes are the main source of information, but the main eyes of spiders are ocelli that can form images and, in a few cases, can swivel to track prey. (
  • development variable, often with larval stage Arthropod diversity: four major groups Chelicerata - arachnids, horseshoe "crab" , sea " spiders " Myriapoda - centipedes, millipedes Crustacea - crabs, shrimp, lobsters, barnacles, etc. (
  • Some small arthropods simply absorb oxygen through their thin body coverings. (
  • This compound eye system enables small arthropods equipped with an eye of low acuity to estimate velocity, size or distance of possible food items efficiently. (
  • They are found in all arthropod groups, although they may have evolved more than once within this phylum. (
  • Molluscs represent a third phylum in which highly complex eyes are present. (
  • Thanks to their exoskeletons, arthropods became the world's first land animals some 300 million years ago. (
  • 8. Arthropods exoskeletons made life on land possible. (
  • Arthropods need to get rid of exoskeletons and grow new ones periodically. (
  • Exoskeletons also block sensory information, so arthropods have evolved various other ways to sense their environment like compound eyes and other sensory organs. (
  • It is worth adding, perhaps, that it is only the male strepsipteran that has these eyes which it employs on its nuptial flight, in search for the female which is permanently enclosed in a host insect (often a wasp), with only the reproductive organs protruding. (
  • We have therefore investigated visual opsins in the ocelli and compound eyes of the two-spotted cricket Gryllus bimaculatus , a hemimetabolous insect. (
  • Our data show that cricket eyes are spectrally more specialized than has previously been assumed, suggesting that similar adaptations in other insect species might have been overlooked. (
  • The arrangement of spectral receptor types within some ommatidia of the cricket compound eyes differs from the generally accepted pattern found in holometabolous insect taxa and awaits a functional explanation. (
  • From the opsin phylogeny, we conclude that gene duplications, which permitted differential opsin expression in insect ocelli and compound eyes, occurred independently in several insect lineages and are recent compared to the origin of the eyes themselves. (
  • Some insect larvae, e.g., caterpillars, have a different type of simple eye known as stemmata. (
  • Hateren JH van (1987) Photoreceptor optics and neural microcircuitry in the insect eye. (
  • Buschbeck EK and M Friedrich (2008) Evolution of insect eyes: tales of ancient heritage, deconstruction, reconstruction, remodeling, and recycling. (
  • I became interested in eye evolution early in my career when I studied the compound eyes of insect and crustacean and discovered several previously unknown principles of visual optics 1,2,3 . (
  • In animal apposition compound eyes, each ommatidium consists of a microlens that focuses light from a specific section of the insect field of view through an optical waveguide onto an independent set of photoreceptors. (
  • A researcher at the University of Arizona has discovered compounds derived from Photorhabdus, an insect pathogenic bacterium, that have antimicrobial and nematicidal properties that can potentially replace chemical pesticides. (
  • DOVING K.B. & MILLER W.H. 1969: Function of insect compound eyes containing crystalline tracts. (
  • Their expression pattern divides the retina into distinct regions: (1) the polarization-sensitive dorsal rim area with blue- and UV-opsin, (2) a newly-discovered ventral band of ommatidia with blue- and green-opsin and (3) the remainder of the compound eye with UV- and green-opsin. (
  • We investigated the external morphology, eye size, facet size, and numbers of ommatidia and ommatrichia of the compound eyes of Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), Bactrocera tau (Walker) and Bactrocera dorsalis (Hendel) using light and scanning electron microscopy. (
  • On the other hand, some modes of life demand enhanced visual acuity, which in compound eyes demands a larger number of ommatidia, which in turn demands larger compound eyes. (
  • Good examples may be seen in the Mantodea and Mantispidae, in which seeing prey from particular ommatidia in both compound eyes at the same time, indicates that it is in the right position to snatch in a close-range ambush. (
  • Compound eyes are often not completely symmetrical in terms of ommatidia count. (
  • auto-immunofluorescence visualises the ommatidia of the compound eye (CE), the optic lobe (OL) and the central brain (CB). (
  • Arthropods have compound eyes made of several visual units called as ommatidia. (
  • compound eye -- Found in many but not all arthropods , a compound eye is composed of a large number of small, closely packed simple eyes ( ommatidia ), each with its own lens and nerve receptors. (
  • The number of ommatidia (180) is comparable to those of the eyes of fire ants and bark beetles. (
  • ANTON-ERXLEBEN F. & LANGER H. 1988: Functional morphology of the ommatidia in the compound eye of the moth, Antherea polyphemus (Insecta: Saturniidae). (
  • BARLOW H.B. 1952: The size of ommatidia in apposition eyes. (
  • The arachnids have simple (as opposed to compound) eyes. (
  • This section contains the eyes (five pairs), one pair of small pincers/chelicerae used to move food towards the mouth, five pairs of walking legs (the first four with claws, the last with a leaf-like structure used for pushing) (DNR 2005), the mouth (located in between the legs), the brain , and the heart . (
  • For example, most vertebrates have the classic "camera eye. (
  • The supposed evolutionary ancestor of all vertebrates should have passed its specific camera eye design down to its descendants-modern vertebrates. (
  • But certain vertebrates use completely different eyes. (
  • Instead, for example, spineless squids and octopi use the same basic camera-eye anatomy as vertebrates -albeit with a few optimizations for life underwater. (
  • Many other organisms, such as vertebrates and Cephalopoda are similarly and analogously dichoptic, which is the common state in animals that are members of the Bilateria and have functionally elaborate eyes. (
  • In arthropods, typically r-opsins are responsible for vision, whereas in vertebrates c-opsins are components of visual photoreceptors. (
  • It seems like a simple evolutionary distinction, with arthropods exhibiting one pattern and vertebrates another, but the story isn't as clean and simple as all that. (
  • Pax-6 in vertebrates and its homolog eyeless in Drosophila are known to be essential for eye development. (
  • Recent data based on the demonstration that the paired domain/homeodomain transcription factor, Pax-6/eyeless, has a critical role in eye development in vertebrates ( 5 - 10 ) and Drosophila ( 11 ) support the idea of a monophyletic origin of the eyes. (
  • Heterozygous mutations in Pax-6 of vertebrates are associated with a variety of eye diseases, including aniridia in human and Small eye ( Sey ) in rodents ( 5 , 6 , 8 ). (
  • Taken together these data suggest that two types of image-forming eyes, complex eyes of vertebrates and compound eyes of arthropods, share-at least partially-developmental pathways. (
  • The complex eyes of cephalopod molluscs and vertebrates have been considered a classical example of convergent evolution ( 18 ). (
  • In all non-vertebrate eyes, and in the pineal or dorsal eyes of primitive vertebrates, the photoreceptors point toward the light. (
  • Horseshoe crab is the common name for various marine chelicerate arthropods of the family Limulidae , and in particular the extant species Limulus polyphemus of the Atlantic of North America. (
  • Each major group of arthropods is characterised by a particular tagmosis. (
  • Centipedes are a diverse group of Arthropods with a range of behavioral characteristics. (
  • Mandibulata is a group of arthropods characterized by mandibles (mouthparts) used for biting, cutting, and holding food. (
  • Major groups of arthropods exhibit a characteristic tagmosis. (
  • Friedrich M and Tautz D (1995) Ribosomal DNA phylogeny of the major extant arthropod classes and the evolution of myriapods. (
  • Approximately 80 percent of extant (living) animal species are classified as arthropods. (
  • Extant arthropods are diverse and ubiquitous, forming a major constituent of most modern ecosystems. (
  • Arthropods include the only invertebrate group to evolve flight. (
  • The differences are significant enough that it has been argued as to whether the vertebrate and invertebrate eye arose by convergent or divergent evolution ( Nilson, 1966 ). (
  • Most anthropomorphic invertebrate characters tend to be arthropods, perhaps because of their ubiquitous presence across the world. (
  • Indeed, arthropods far outnumber all other types of animals combined, with an estimated 1 million species. (
  • All species of arthropods also share a basic body plan. (
  • In the simplest arthropod species, this fluid simply squishes to and fro. (
  • The results contribute to the further exploration of the relationship between the ultrastructural dimensions of the compound eye features and the visually-based behaviors of these 3 Bactrocera species. (
  • Similarly, "most known starfish species possess a compound eye at the tip of each arm, which, except for the lack of true optics, resembles [the] arthropod compound eye. (
  • Most species of Arthropoda with compound eyes bear just two eyes that are located separately and symmetrically, one on each side of the head. (
  • Traditionally, it has been assumed that eyes evolved about 40 to 65 times independently, [6] but more recent genetic evidence seems to suggest that all the eye variations that exist today evolved from the same very simple eye (most famously, the Pax6 gene or variants ( PaxB , PaxC ) exists in all species with sight - from fruit flies to humans - suggesting a common ancestor ). (
  • Size varies by species (1 to 1¾ inch long), brown to grayish-green, prominent head, large compound eyes, enlarged hind legs for jumping. (
  • Only the simple eyes are present, and the mouth is the chewing type, even in species whose adults have other kinds of mouthparts. (
  • Millipedes are arthropods in the class Diplopoda, which contains approximately 10,000 species in 13 orders and 115 families. (
  • Most of the major animal groups comprise species with a simple eye spot. (
  • It will be interesting to see if they can image other species of trilobite to get an evolutionary look at how eyes and perhaps primitive retinas developed over 500 million years ago. (
  • This first CURVACE yields several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. (
  • Many species had large, compound eyes. (
  • Approximately one million arthropod species have been described to date. (
  • A mandible is either of a pair of arthropod mouthparts used for biting, cutting, and holding food. (
  • The order evolved more than 300 million years ago with enlarged hind legs, mandibulate mouthparts and large compound eyes. (
  • This development set the first arthropods apart from their soft-bodied ancestors, and may be what allowed some early arthropods to crawl out of the water without drying out in the open air or sagging under their own weight. (
  • This taxon and many other extinct early arthropods were coded into an extensive cladistic analysis of panarthropods to determine their affinities and explore relationships within the arthropod stem-lineage. (
  • Anderson DT (1973) Embryology and Phylogeny in Annelids and Arthropods. (
  • Some annelids and bivalves also have apposition eyes. (
  • Thus whilst there is little doubt that the ancestral arthropod possessed some sort of eye it is inferred to have been relatively simple and by implication the animal was slow moving. (
  • In all arthropods the plesiomorphic (ancestral character state) kind of visual system commonly is considered to be the compound eye. (
  • Apposition eyes are the most common form of eye, and are presumably the ancestral form of compound eye. (
  • The authors indicate that it might be close to the ancestral line for arthropods - jointed animals ranging from lobsters to ladybugs. (
  • The reduction of compound eyes and loss of one pair (and in some extinct groups, two pair) of pulmonary books (and the corresponding fusion of opisthosomal sternites), so characteristic of modern scorpions, occurs in this group. (
  • The Canadian Encyclopedia (accessed August 16, 2018). (
  • Oakley TH and Cunningham CW (2002) Molecular phylogenetic evidence for the independent evolutionary origin of an arthropod compound eye. (
  • Eye designs crisscross imagined evolutionary tree branches. (
  • As an organ developed via the opportunistic twists and turns of evolutionary processes, the human eye is explainable. (
  • The sea creature's eyes belong to an earlier period of the 'Cambrian explosion' in evolutionary terms, but as there is no evidence of eyes in the pre-Cambrian period, it suggests complex eyes developed extraordinarily quickly. (
  • These similarities suggest that all eyes have a common evolutionary ancestor. (
  • No discussion of eye evolution is possible without a general understanding of the evolutionary history of the group of interest. (
  • While we recognize that our understanding of the evolution of Crustacea is far from complete, we believe that a discussion of eye design, from both anatomical and molecular perspectives, illustrates many key evolutionary principles. (
  • Within this review, we highlight some of the typical and unusual eye designs within the Crustacea and discuss their evolutionary implications. (
  • An alternative view suggesting a common evolutionary origin of the various eye types has also been proposed ( 4 ). (
  • The eyes are interpreted as having been derived from individuals of the early crustacean Henningsmoenicaris scutula pointing to the existence of highly efficiently developed eyes in the early evolutionary lineage leading towards the modern Crustacea. (
  • Oakley, T. and Cunningham, C., Molecular phylogenetic evidence for the independent evolutionary origin of an arthropod compound eye, Proceedings of the National Academy of Sciences USA 99 (3):1426-1430, 5 February 2002. (
  • Note that we are told that the find "helps track the evolution of eyes and vision in arthropods over time" but in this case, it appears that their wasn't much evolution: They "developed apposition compound eyes during the earliest evolutionary stages of the group and stuck with this design throughout their history. (
  • Can you name the Arthropod Morphology? (
  • Giribet G, Edgecombe GD and Wheeler WC (2001) Arthropod phylogeny based on eight molecular loci and morphology. (
  • These arthropods differed considerably in morphology and bore little resemblance to their supposed anomalocaridid ancestors. (
  • Figure 3: Image formation in apposition and superposition eyes. (
  • This is called a superposition eye. (
  • The general strategies shown in this development could be applicable to other compound eye devices, such as those inspired by moths and lacewings (refracting superposition eyes), lobster and shrimp (reflecting superposition eyes), and houseflies (neural superposition eyes). (
  • Ectoedemia argyropeza (Zeller, 1839) possesses a compound eye that exhibits features of both apposition and superposition type eyes. (
  • Like apposition eyes, the eye of E. argyropeza lacks a clear-zone, which in superposition eyes separates the distal dioptric from the proximal light-perceiving structures. (
  • With screening pigments withdrawn, tracheal tapetum exposed, and distal rhabdom diameters reduced, the proximal and in the dark enlarged rhabdom is then in a position to capture photons that have entered the eye through not only the ommatidial window above, but other facets as well even in the absence of a clear-zone and superposition optics. (
  • HORRIDGE G.A. 1971: Alternatives to superposition images in clear zone compound eyes. (
  • This diversity includes many different examples of both simple and compound eyes, each with standard or uniquely crustacean features. (
  • In this review, we focus on the anatomical variation, optical principles, and molecular diversity of crustacean compound eyes to illustrate how the complicated structures involved in vision are adapted for particular environments. (
  • Using this knowledge as a starting point, and considering what is known of crustacean evolution overall, we present the most recent ideas of how crustacean compound eyes have evolved and show how eyes that are based on fundamentally different optical principles can in fact be derived from each other and thus be closely related through common descent. (
  • The wide range of light environments represented by these diverse habitats has operated together with the overall morphological diversity within the Crustacea to produce a dizzying array of crustacean visual systems, based on eyes ranging from simple pigment cups to compound eye designs not seen in any other animal. (
  • Phylogenetic distribution of optical eye designs within the major crustacean lineages. (
  • Consequently, in this review of crustacean visual evolution, we will restrict our discussion to the compound eyes. (
  • Henningsmoenicaris scutula was an early crustacean just a few millimeters long with compound eyes. (
  • The stalks, which allowed the eye structures to rest above the animal's body, were probably also moveable, so the crustacean would have had an even larger range of view . (
  • Buschbeck (2010) Retinal ultrastructure in the principle eyes may mediate polarization sensitivity in the first instar larva of the diving beetle Thermonectus marmoratus (Insecta: Dytiscidae). (
  • The chambered nautilus, a cephalopod along with squid, hunts its prey with pinhole eyes, albeit without lenses. (
  • Fossilized eye stalks helped Henningsmoenicaris scutula catch its prey. (
  • Early scorpions had large compound eyes, but were otherwise similar to living forms. (
  • Studying the phylogeny and expression pattern of opsins is thus crucial for understanding the evolution of animal eyes. (
  • Their apposition eyes, however, have only around 30 times greater optical sensitivity than the eyes of their closest diurnal relatives, a fact that is apparently inconsistent with their remarkable nocturnal visual abilities. (
  • EGUCHI E. 1982: Retinular fine structure in compound eyes of diurnal and nocturnal shingid moths. (
  • A cross‐section of a typical arthropod segment showing basic characteristics. (
  • Despite their vast number and varied existence, all arthropods share certain characteristics. (
  • Compound eyes in arthropods demonstrate distinct imaging characteristics from human eyes, with wide angle field of view, low aberrations, high acuity to motion and infinite depth of field. (
  • Typically, arthropods have reproductive systems that are either distinctly male or female, and therefore reproduce sexually. (
  • Typically, magic words like "emerge," "evolve," and "appear" substitute for evidence or for a realistic explanation of each supposed gradual step in eye evolution. (
  • Although the name suggests that centipedes have a hundred legs, these arthropods typically have 15 to over 30 pairs of legs. (
  • Their anatomy displays characteristic features such as compound eyes, wings and bristles that can be used as phenotypes to study neurodegeneration without affecting the survival of the fly. (
  • 2. A marking that resembles an eye, as on the wings of some butterflies. (
  • The first arthropod fossils date to the Cambrian @ 555 million years ago (mya). (
  • Exquisitely preserved fossils, discovered in Sweden in the 1970s, include six tiny stalked eye structures, each less than 0.01 inches (a third of a millimeter) long. (
  • Older compound eyes have been found , but the fossils aren't complete enough to determine to this extent how the animals carrying them saw. (
  • At a more fundamental level there is now evidence that a fully functioning compound eye with precise focus and good visual acuity has evolved at least twice in the arthropods. (
  • Techniques are given for measuring the size and spatial arrangement of the lenses of schizochroal eyes and the angular bearings of their lens-axes, from which may be inferred the angular range of vision of the whole eye and the relative visual acuity in different directions. (
  • Molecular, developmental, and morphological studies have revealed some common ground in the eyes of virtually all multicellular animals. (
  • The morphological differences of the various eyes have been considered as evidence that they did not share a common ancestor and thus are polyphyletic in origin. (
  • It is now generally accepted for a variety of reasons - morphological as well as physiologica- that the visual systems of arthropods provide a suitable model for the study of information proces sing in neuronal networks. (
  • GOKAN N. & MEYER-ROCHOW V.B. 2000: Morphological comparisons of compound eyes in Scarabaeoidea (Coleoptera) related to the beetles' daily activity maxima and phylogenetic positions. (
  • Most arthropods have at least one of two types of eye: lateral compound eyes, and smaller median ocelli, which are simple eyes. (
  • Ocelli can detect lower light levels, and have a faster response time, while compound eyes are better at detecting edges and are capable of forming images. (
  • The result is that the eyes occupy most of the available surface of the head, reducing the area of the frons and the vertex and crowding the ocelli, if any. (
  • Smith has observed, the larger workers have simple eyes ( ocelli ), which though small can be plainly distinguished, whereas the smaller workers have their ocelli rudimentary. (
  • Its two huge eyes extend in two vast oval patches from the centre of the top of the cranium down either side of the head to below the roots of the horns, so that these weapons really grow out from the lower part of the eyes, which are composed of several thousand ocelli each. (
  • For the purposes of this report, we define ocelli and eyes as follows (after Bok et al. (
  • Centipedes (Latin, = hundred foot) are exclusively predatory arthropods belonging to the class Chilopoda (Latin, = fang foot). (
  • Centipedes are essential predators in our ecosystem, feeding on numerous other arthropods. (
  • House centipedes, unlike other centipedes, have well-developed faceted eyes. (
  • In actuality, arthropods commonly known as wood eating centipedes are millipedes . (
  • Unlike most other centipedes, house centipedes and their close relatives have well-developed compound eyes which are sensitive to ultraviolet as well as visible light. (
  • Centipedes are long-lived as arthropods go. (
  • They are also possessed by Limulus, the horseshoe crab, and there are suggestions that other chelicerates developed their simple eyes by reduction from a compound starting point. (
  • Animals with new body plans-arthropods, brachiopods, chordates-appeared suddenly about 530 million years ago. (
  • How did the eye evolve? (
  • But even with these conservative assumptions, the time taken to evolve a fish eye from flat skin was minuscule: fewer than 400,000 generations. (
  • For the kinds of small animals we are talking about, we can assume one generation per year, so it seems that it would take less than half a million years to evolve a good camera eye. (
  • A possible strategy used to evolve complex image-forming eyes from the primitive eyes present in the last common ancestor is the use of similar developmental mechanisms with the same or closely related transcription factors. (
  • Years of work on these questions revealed functional routs by which the different types of compound eye could evolve into each other 4,5,6,7 . (
  • The conclusion here is that eyes did not evolve from poor to perfect, but from optimally controlling few and simple behaviours to optimally controlling numerous complex and demanding behaviours. (
  • Arthropod limbs may be uniramous (one branched) or biramous (two branched). (
  • This fossil documents a suite of primitive arthropod features, such as multi-podomerous limbs and a posterior tagma composed of three pairs of lateral flaps. (
  • Strangely, apposition eyes are also found in several groups of bees and wasps (and also ants) that have evolved a nocturnal lifestyle. (
  • HOGLUND G. 1966: Pigment migration, light screening and receptor sensitivity in the compound eye of nocturnal Lepidoptera. (
  • Arthropods exhibit unparalleled diversity and abundance along with a correspondingly large ecological impact. (
  • The short answer is that there are fundamentally two different kinds of eyes based on the biology of the cell types, and our common bilaterian ancestor had both-and the diversity arose in elaborations on those two types. (
  • Different explanations for the diversity of eyes have been proposed. (
  • Arthropods evolved in the Cambrian period 500 to 600 million years ago. (
  • Even some jellyfish use small camera eyes. (
  • It also promptly pushes the timeline back to 600 million years, and describes work done on jellyfish eyes. (
  • Jellyfish are the simplest animals that have anything that can be described as an eye, and box jellyfish were known to have numerous eyes clustered on four sensory clubs suspended in little pockets on the inside of the bell. (
  • A) One of the four sensory clubs (rhopalia) of a box jellyfish, showing the two lens eyes. (
  • But after many investigations of their visually guided behaviour we had to change our mind and accept that the acuity of box jellyfish eyes is perfectly matched to the needs of the few visually guided behaviours they are capable of. (
  • citation needed] The arthropods ancestrally possessed compound eyes, but the type and origin of this eye varies between groups, and some taxa have secondarily developed simple eyes. (
  • Recently, an enigmatic r-opsin-like protein called arthropsin has been identified in various bilaterian taxa, including arthropods, lophotrochozoans, and chordates, by performing transcriptomic and genomic analyses. (
  • 1997) Evidence for a clade of nematodes, arthropods and other moulting animals. (
  • Mandibulata is held to be a sister group to the rest of arthropods, the clade Arachnomorpha ( Chelicerata + Trilobita ). (
  • It is generally agreed that the anomalocaridids, a clade of large nektonic predators [ 6 , 7 ], represent the nearest non-arthropod outgroup [ 7 - 9 ], but the identity of the first arthropods remains obscure. (
  • They possess the most plesiomorphic, euypterid-like legs and sternocoxal arrangements, as well as well-develpoed lateral compound eyes. (
  • This design represents a vast improvement in sensitivity over the apposition compound eye ( Fig. 1A ), a design in which single photoreceptors receive light only from the single corneal facet lens residing in the same ommatidium. (
  • Each small eye, known as an ommatidium, consists of a corneal lens, a crystalline cone and a light-sensitive organ at the base. (
  • A significant convergence between the calcitic compound eye of the trilobite is found with remarkably equivalent structures in the tips of the arms of the brittle-stars (echinoderms), and these latter structures derived from the mesodermal skeleton (stereom) are evidently optical. (
  • Here we are able to show the excellently preserved internal structures of the compound eye of a 429 Mya old Silurian trilobite, Aulacopleura koninckii (Barrande, 1846). (
  • The trilobite had a compound, lens-focusing eye. (
  • However, a very cool new study that examines trilobite eyes through X-ray tomography by Brigitte Schoenemann and Euan N. K. Clarkson reveals how these cells looked, down, perhaps to the cellular level. (
  • Mayer G, Whitington PM, Sunnucks P and Pflüger H‐J (2010) A revision of brain composition in Onychophora (velvet worms) suggests that the tritocerebrum evolved in arthropods. (
  • This suggests that the PCE of the compound eye of adult males is the greatest of all groups. (
  • Furthermore, this suggests that the last common ancestor of these organisms at the protostome-deuterostome divergence possessed eyes in which a Pax-6 gene was already active ( 16 ). (
  • Arthropods must therefore periodically replace their shells as they grow or change shape. (
  • The rigid cuticle inhibits growth, so arthropods replace it periodically by molting. (
  • The eyes have it: world's oldest predator found,, 7 December 2011 (based on Paterson, J. et al . (
  • The spectral absorption properties of visual pigments are mainly determined by their opsins, and thus opsins are crucial for understanding the adaptations of animal eyes. (
  • We assign three of these opsins to visual pigments found in the compound eyes with peak absorbances in the green (515 nm), blue (445 nm) and UV (332 nm) spectral range. (
  • Arthropod blood is usually colourless because it lacks the respiratory pigments of vertebrate blood. (
  • it is a continuation of the sclera (the white of the eye), the tough outer coat that helps protect the delicate mechanism of the eye. (
  • a substance consisting of polysaccharide which forms most of the hard outer skeletons of arthropods and of the cell-walls of fungi. (
  • Unlike the two outer layers of the eye, the retina does not extend to the front of the eyeball. (
  • Accessory structures of the eye are the lacrimal gland and its ducts in the upper lid, which bathe the eye with tears tears, watery secretion of the lacrimal gland, which is located at the outer corner of the eye socket immediately above the eyeball. (
  • To obtain insight into sensory structures, such as those of compound eyes, is another challenge for different reasons. (
  • A study on the anatomy of the internal structures of the compound eye of Aulacopleura koninckii is published by Schoenemann & Clarkson (2020). (
  • 1 Also, the chameleon's pinhole eye design uses concave lenses that spread out a narrow section of incoming light onto a broader retina. (
  • The international team, whose findings are published in the journal Nature , discovered that Anomalocaris' 2-3cm oval eyes are made up of at least 16,000 hexagonal-shaped lenses, that are, in turn, arranged in bigger hexagonals. (
  • In previous fossil discoveries only the outline of Anomalocaris' eyes remained, but the new fossil had its lenses intact. (
  • Inspired by the complex fly eye, an interdisciplinary team led by researchers at the University of Illinois at Urbana-Champaign and Northwestern University has developed a hemispherical digital camera with nearly 200 tiny lenses, delivering exceptionally wide-angle field of view and sharp images. (
  • Humans capture pictures using the two lenses of our relatively flat eyes, while a top-of-the-line SLR camera has just one flat lens. (
  • These eyes had elongated lenses composed of calcite that modeling has revealed to provide excellent optical properties with good depth of field and little to no spherical aberration. (
  • To our surprise we found that some of their tiny eyes had lenses with graded-index optics 15 . (
  • They find that its eyes, mounted on the ends of stalks, were compound eyes, each with 16,000 separate lenses. (
  • Arthropods such as mites and lice flourish on the bodies of almost every kind of animal on Earth. (
  • It shows the characteristic elements of a modern apposition eye, consisting of 8 (visible) receptor cells, a rhabdom, a thick lens, screening pigment (cells), and in contrast to a modern type, putatively just a very thin crystalline cone. (
  • The tiny stalked compound eyes described here probably possessed too few facets to form a proper image, but they represent a sophisticated system for detecting moving objects. (
  • Thomas, B. Shrimp Eye May Inspire New DVD Technology . (
  • Fossilised eyes of the giant shrimp-like Anomalocaris have been found by palaeontologists excavating the Emu Bay shale on Kangaroo Island , South Australia. (
  • Arthropods provide a whole series of insights into the evolution of vision and the nature of convergence. (
  • In contrast, the need for particular functions may not require extremely large eyes, but do require great resolution and good stereoscopic vision for precise attacks. (
  • Their eyes accordingly are placed in a good position for all-round vision, plus particular concentration on the anterior median plane. (
  • for example, the Gyrinidae spend most of their adult lives on the surface of water, and have their two compound eyes split into four halves, two for underwater vision and two for vision in air. (
  • In the case of some Ephemeroptera the effect is so exaggerated that the upper part of the eye is elevated like a risen cupcake, while its lower part that serves for routine vision looks like a separate organ. (
  • The only one of today's arthropods that has clearer vision than the Anomalocaris is the dragonfly. (
  • The eyes are situated in the front of the head in such a way that human beings have stereoscopic vision, the ability to judge distances. (
  • A theory put forth by Johannes Müller to explain the vision of Arthropods possessed of compound eyes. (
  • eye, organ of vision and light perception. (
  • Comparisons are made with the adult eyes of Acaste downingiae macrops (Salter) and Acastoides constricta (Salter).Variation of lens-size and strong differentiation between the relative acuity in the horizontal and vertical directions of vision are perhaps the most significant features of the eyes of Acastinae, and the latter is interpreted as indicative of movement-perceiving eyes. (
  • These animals belong to three animal phyla, which are the only ones where advanced eyes and high-resolution vision has evolved. (
  • To understand the evolution of eyes and vision I thought it was necessary to learn more about all the intermediate stages between the non-directional photoreceptor cells and an advanced eye with high-resolution vision. (
  • At first, such a low spatial resolution, about 600 times blurrier than human foveal vision, seemed to support the notion that eyes evolved from poor to perfect. (
  • These vision organs yield, compared to vertebrate single-lens eye, low spatial resolution, but a significantly wider distortion-free field of view as well as a very high sensitivity and temporal resolution. (
  • Smart, large eyes with good vision. (
  • Compound eyes are important visual sensory organs with the capacity to distinguish colors and shapes ( Briscoe & Chittka 2001 ), detect moving objects, and perceive the plane of polarized light ( Horvath & Varju 2003 ). (
  • An eye is a differentiated sensory organ that detects light , and is very likely the organ you're reading this with. (
  • Almost all arthropods lay eggs, but scorpions give birth to live young after the eggs have hatched inside the mother. (
  • [7] [8] Whether this actually indicates a common ancestor is debated, as it may also be the case that the genes could have served a different function unrelated to the eye. (
  • All arthropods share a common ancestor that lived more than 550 million years ago. (
  • As an organ designed and created by an infinitely wise deity , the human eye is inexcusable. (
  • However, given the fact that there are a number of different classes of eyes which, collectively, exhibit a wide range of degrees of complexity, it is difficult to understand what would absolutely prevent a lineage from acquiring a series of successive increases in the complexity of its eyes, eventually ending up with something akin to the human organ. (
  • In spite of being a marvellous and complex organ, the evolution of the eye is actually not that difficult. (
  • In the embryo the eye develops as a direct extension of the brain, and thus is a very delicate organ. (
  • We demonstrate that alternatively spliced RNAs derived from a single Pax-6 gene in the squid ( Loligo opalescens ) are expressed in the embryonic eye, olfactory organ, brain, and arms. (