Vertebrates: Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.Arthropod Vectors: Arthropods, other than insects and arachnids, which transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Host-Parasite Interactions: The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Culicidae: A family of the order DIPTERA that comprises the mosquitoes. The larval stages are aquatic, and the adults can be recognized by the characteristic WINGS, ANIMAL venation, the scales along the wing veins, and the long proboscis. Many species are of particular medical importance.Ticks: 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)Salivary Glands: Glands that secrete SALIVA in the MOUTH. There are three pairs of salivary glands (PAROTID GLAND; SUBLINGUAL GLAND; SUBMANDIBULAR GLAND).Alphavirus: A genus of TOGAVIRIDAE, also known as Group A arboviruses, serologically related to each other but not to other Togaviridae. The viruses are transmitted by mosquitoes. The type species is the SINDBIS VIRUS.Insect Vectors: Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Ixodes: 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.Arboviruses: Arthropod-borne viruses. A non-taxonomic designation for viruses that can replicate in both vertebrate hosts and arthropod vectors. Included are some members of the following families: ARENAVIRIDAE; BUNYAVIRIDAE; REOVIRIDAE; TOGAVIRIDAE; and FLAVIVIRIDAE. (From Dictionary of Microbiology and Molecular Biology, 2nd ed)Plasmodium gallinaceum: A protozoan parasite that causes avian malaria (MALARIA, AVIAN), primarily in chickens, and is transmitted by the Aedes mosquito.Malaria, Avian: Any of a group of infections of fowl caused by protozoa of the genera PLASMODIUM, Leucocytozoon, and Haemoproteus. The life cycles of these parasites and the disease produced bears strong resemblance to those observed in human malaria.Arachnid Vectors: Members of the class Arachnida, especially SPIDERS; SCORPIONS; MITES; and TICKS; which transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Sporozoites: The product of meiotic division of zygotes in parasitic protozoa comprising haploid cells. These infective cells invade the host and undergo asexual reproduction producing MEROZOITES (or other forms) and ultimately gametocytes.Nymph: The immature stage in the life cycle of those orders of insects characterized by gradual metamorphosis, in which the young resemble the imago in general form of body, including compound eyes and external wings; also the 8-legged stage of mites and ticks that follows the first moult.Borrelia burgdorferi: A specific species of bacteria, part of the BORRELIA BURGDORFERI GROUP, whose common name is Lyme disease spirochete.Insect Bites and Stings: Bites and stings inflicted by insects.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Arbovirus Infections: Infections caused by arthropod-borne viruses, general or unspecified.Disease Vectors: Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.Plasmodium berghei: A protozoan parasite of rodents transmitted by the mosquito Anopheles dureni.Arthropods: 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.Plasmodium: A genus of protozoa that comprise the malaria parasites of mammals. Four species infect humans (although occasional infections with primate malarias may occur). These are PLASMODIUM FALCIPARUM; PLASMODIUM MALARIAE; PLASMODIUM OVALE, and PLASMODIUM VIVAX. Species causing infection in vertebrates other than man include: PLASMODIUM BERGHEI; PLASMODIUM CHABAUDI; P. vinckei, and PLASMODIUM YOELII in rodents; P. brasilianum, PLASMODIUM CYNOMOLGI; and PLASMODIUM KNOWLESI in monkeys; and PLASMODIUM GALLINACEUM in chickens.Aedes: A genus of mosquitoes (CULICIDAE) frequently found in tropical and subtropical regions. YELLOW FEVER and DENGUE are two of the diseases that can be transmitted by species of this genus.Salivary Proteins and Peptides: Proteins and peptides found in SALIVA and the SALIVARY GLANDS. Some salivary proteins such as ALPHA-AMYLASES are enzymes, but their composition varies in different individuals.Birds: Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.Ceratopogonidae: A family of biting midges, in the order DIPTERA. It includes the genus Culicoides which transmits filarial parasites pathogenic to man and other primates.Life Cycle Stages: The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Rodentia: A mammalian order which consists of 29 families and many genera.Host-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.Culex: A genus of mosquitoes (CULICIDAE) commonly found in tropical regions. Species of this genus are vectors for ST. LOUIS ENCEPHALITIS as well as many other diseases of man and domestic and wild animals.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Encephalitis, Tick-Borne: Encephalitis caused by neurotropic viruses that are transmitted via the bite of TICKS. In Europe, the diseases are caused by ENCEPHALITIS VIRUSES, TICK-BORNE, which give rise to Russian spring-summer encephalitis, central European encephalitis, louping ill encephalitis, and related disorders. Powassan encephalitis occurs in North America and Russia and is caused by the Powassan virus. ASEPTIC MENINGITIS and rarely encephalitis may complicate COLORADO TICK FEVER which is endemic to mountainous regions of the western United States. (From Joynt, Clinical Neurology, 1996, Ch26, pp14-5)Anopheles: A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.Zebrafish: An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.Lyme Disease: An infectious disease caused by a spirochete, BORRELIA BURGDORFERI, which is transmitted chiefly by Ixodes dammini (see IXODES) and pacificus ticks in the United States and Ixodes ricinis (see IXODES) in Europe. It is a disease with early and late cutaneous manifestations plus involvement of the nervous system, heart, eye, and joints in variable combinations. The disease was formerly known as Lyme arthritis and first discovered at Old Lyme, Connecticut.Feeding Behavior: Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.Encephalitis Viruses, Tick-Borne: A subgroup of the genus FLAVIVIRUS that causes encephalitis and hemorrhagic fevers and is found in eastern and western Europe and the former Soviet Union. It is transmitted by TICKS and there is an associated milk-borne transmission from viremic cattle, goats, and sheep.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Flavivirus: A genus of FLAVIVIRIDAE containing several subgroups and many species. Most are arboviruses transmitted by mosquitoes or ticks. The type species is YELLOW FEVER VIRUS.Alphavirus Infections: Virus diseases caused by members of the ALPHAVIRUS genus of the family TOGAVIRIDAE.Primate Diseases: Diseases of animals within the order PRIMATES. This term includes diseases of Haplorhini and Strepsirhini.Protozoan Proteins: Proteins found in any species of protozoan.Encephalitis Virus, Eastern Equine: A species of ALPHAVIRUS causing encephalomyelitis in Equidae and humans. The virus ranges along the Atlantic seaboard of the United States and Canada and as far south as the Caribbean, Mexico, and parts of Central and South America. Infections in horses show a mortality of up to 90 percent and in humans as high as 80 percent in epidemics.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Ixodidae: A family of hardbacked TICKS, in the subclass ACARI. Genera include DERMACENTOR and IXODES among others.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Psychodidae: Small, hairy, moth-like flies which are of considerable public health importance as vectors of certain pathogenic organisms. Important disease-related genera are PHLEBOTOMUS, Lutzomyia, and Sergentomyia.Mammals: Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.Disease Reservoirs: Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (DISEASE VECTORS) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks.Trypanosoma: A genus of flagellate protozoans found in the blood and lymph of vertebrates and invertebrates, both hosts being required to complete the life cycle.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Malaria: A protozoan disease caused in humans by four species of the PLASMODIUM genus: PLASMODIUM FALCIPARUM; PLASMODIUM VIVAX; PLASMODIUM OVALE; and PLASMODIUM MALARIAE; and transmitted by the bite of an infected female mosquito of the genus ANOPHELES. Malaria is endemic in parts of Asia, Africa, Central and South America, Oceania, and certain Caribbean islands. It is characterized by extreme exhaustion associated with paroxysms of high FEVER; SWEATING; shaking CHILLS; and ANEMIA. Malaria in ANIMALS is caused by other species of plasmodia.Leishmania: A genus of flagellate protozoa comprising several species that are pathogenic for humans. Organisms of this genus have an amastigote and a promastigote stage in their life cycles. As a result of enzymatic studies this single genus has been divided into two subgenera: Leishmania leishmania and Leishmania viannia. Species within the Leishmania leishmania subgenus include: L. aethiopica, L. arabica, L. donovani, L. enrietti, L. gerbilli, L. hertigi, L. infantum, L. major, L. mexicana, and L. tropica. The following species are those that compose the Leishmania viannia subgenus: L. braziliensis, L. guyanensis, L. lainsoni, L. naiffi, and L. shawi.Host Specificity: The properties of a pathogen that makes it capable of infecting one or more specific hosts. The pathogen can include PARASITES as well as VIRUSES; BACTERIA; FUNGI; or PLANTS.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.Insect Proteins: Proteins found in any species of insect.Rickettsia Infections: Infections by the genus RICKETTSIA.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Chordata, Nonvertebrate: A portion of the animal phylum Chordata comprised of the subphyla CEPHALOCHORDATA; UROCHORDATA, and HYPEROTRETI, but not including the Vertebrata (VERTEBRATES). It includes nonvertebrate animals having a NOTOCHORD during some developmental stage.Embryo, Nonmammalian: The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.Zebrafish Proteins: Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).Virulence: The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.Trypanosoma cruzi: The agent of South American trypanosomiasis or CHAGAS DISEASE. Its vertebrate hosts are man and various domestic and wild animals. Insects of several species are vectors.Gastrointestinal Tract: Generally refers to the digestive structures stretching from the MOUTH to ANUS, but does not include the accessory glandular organs (LIVER; BILIARY TRACT; PANCREAS).Zoonoses: Diseases of non-human animals that may be transmitted to HUMANS or may be transmitted from humans to non-human animals.RNA, Protozoan: Ribonucleic acid in protozoa having regulatory and catalytic roles as well as involvement in protein synthesis.Fishes: A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.Body Patterning: The processes occurring in early development that direct morphogenesis. They specify the body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative positions. Included are axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning, etc.Lampreys: Common name for the only family (Petromyzontidae) of eellike fish in the order Petromyzontiformes. They are jawless but have a sucking mouth with horny teeth.Saliva: The clear, viscous fluid secreted by the SALIVARY GLANDS and mucous glands of the mouth. It contains MUCINS, water, organic salts, and ptylin.West Nile virus: A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE). It can infect birds and mammals. In humans, it is seen most frequently in Africa, Asia, and Europe presenting as a silent infection or undifferentiated fever (WEST NILE FEVER). The virus appeared in North America for the first time in 1999. It is transmitted mainly by CULEX spp mosquitoes which feed primarily on birds, but it can also be carried by the Asian Tiger mosquito, AEDES albopictus, which feeds mainly on mammals.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Genetic Variation: Genotypic differences observed among individuals in a population.Reptiles: Cold-blooded, air-breathing VERTEBRATES belonging to the class Reptilia, usually covered with external scales or bony plates.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Hagfishes: Common name for a family of eel-shaped jawless fishes (Myxinidae), the only family in the order MYXINIFORMES. They are not true vertebrates.Invertebrates: Animals that have no spinal column.Bacterial Proteins: Proteins found in any species of bacterium.DNA, Protozoan: Deoxyribonucleic acid that makes up the genetic material of protozoa.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Plasmodium falciparum: A species of protozoa that is the causal agent of falciparum malaria (MALARIA, FALCIPARUM). It is most prevalent in the tropics and subtropics.Conserved Sequence: A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.Vero Cells: A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.Xenopus Proteins: Proteins obtained from various species of Xenopus. Included here are proteins from the African clawed frog (XENOPUS LAEVIS). Many of these proteins have been the subject of scientific investigations in the area of MORPHOGENESIS and development.Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Amphibians: VERTEBRATES belonging to the class amphibia such as frogs, toads, newts and salamanders that live in a semiaquatic environment.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Homeodomain Proteins: Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).Mice, Inbred BALB CChordata: Phylum in the domain Eukarya, comprised of animals either with fully developed backbones (VERTEBRATES), or those with notochords only during some developmental stage (CHORDATA, NONVERTEBRATE).Oryzias: The only genus in the family Oryziinae, order BELONIFORMES. Oryzias are egg-layers; other fish of the same order are livebearers. Oryzias are used extensively in testing carcinogens.Gene Duplication: Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.Ciona intestinalis: The only species of a cosmopolitan ascidian.Sharks: A group of elongate elasmobranchs. Sharks are mostly marine fish, with certain species large and voracious.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Takifugu: A genus of pufferfish commonly used for research.Xenopus: An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.Chick Embryo: The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.Petromyzon: A genus of primitive fish in the family Petromyzontidae. The sole species is Petromyzon marinus, known as the sea lamprey. The adult form feeds parasitically on other fish species.Bacterial Outer Membrane Proteins: Proteins isolated from the outer membrane of Gram-negative bacteria.Animals, Genetically Modified: ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Genome: The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Drosophila Proteins: Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.Drosophila: A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.Genes, Homeobox: Genes that encode highly conserved TRANSCRIPTION FACTORS that control positional identity of cells (BODY PATTERNING) and MORPHOGENESIS throughout development. Their sequences contain a 180 nucleotide sequence designated the homeobox, so called because mutations of these genes often results in homeotic transformations, in which one body structure replaces another. The proteins encoded by homeobox genes are called HOMEODOMAIN PROTEINS.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Xenopus laevis: The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.Urochordata: A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.Morphogenesis: The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.LizardsFish Proteins: Proteins obtained from species of fish (FISHES).Synteny: The presence of two or more genetic loci on the same chromosome. Extensions of this original definition refer to the similarity in content and organization between chromosomes, of different species for example.DNA, Complementary: Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.Tetraodontiformes: A small order of primarily marine fish containing 340 species. Most have a rotund or box-like shape. TETRODOTOXIN is found in their liver and ovaries.Mesoderm: The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.Photoreceptor Cells, Vertebrate: Specialized PHOTOTRANSDUCTION neurons in the vertebrates, such as the RETINAL ROD CELLS and the RETINAL CONE CELLS. Non-visual photoreceptor neurons have been reported in the deep brain, the PINEAL GLAND and organs of the circadian system.Extremities: The farthest or outermost projections of the body, such as the HAND and FOOT.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Avian Proteins: Proteins obtained from species of BIRDS.Rhombencephalon: The posterior of the three primitive cerebral vesicles of an embryonic brain. It consists of myelencephalon, metencephalon, and isthmus rhombencephali from which develop the major BRAIN STEM components, such as MEDULLA OBLONGATA from the myelencephalon, CEREBELLUM and PONS from the metencephalon, with the expanded cavity forming the FOURTH VENTRICLE.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.Gastrula: The developmental stage that follows BLASTULA or BLASTOCYST. It is characterized by the morphogenetic cell movements including invagination, ingression, and involution. Gastrulation begins with the formation of the PRIMITIVE STREAK, and ends with the formation of three GERM LAYERS, the body plan of the mature organism.DNA-Binding Proteins: 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.Nervous System: The entire nerve apparatus, composed of a central part, the brain and spinal cord, and a peripheral part, the cranial and spinal nerves, autonomic ganglia, and plexuses. (Stedman, 26th ed)Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Ectoderm: The outer of the three germ layers of an embryo.Jaw: Bony structure of the mouth that holds the teeth. It consists of the MANDIBLE and the MAXILLA.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Neural Crest: The two longitudinal ridges along the PRIMITIVE STREAK appearing near the end of GASTRULATION during development of nervous system (NEURULATION). The ridges are formed by folding of NEURAL PLATE. Between the ridges is a neural groove which deepens as the fold become elevated. When the folds meet at midline, the groove becomes a closed tube, the NEURAL TUBE.Symbiosis: The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.TurtlesProtein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Embryonic Development: Morphological and physiological development of EMBRYOS.Embryonic Induction: The complex processes of initiating CELL DIFFERENTIATION in the embryo. The precise regulation by cell interactions leads to diversity of cell types and specific pattern of organization (EMBRYOGENESIS).Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Models, Genetic: Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Nerve Tissue ProteinsCell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Eye: The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.Immunity, Innate: The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.Skates (Fish): The common name for all members of the Rajidae family. Skates and rays are members of the same order (Rajiformes). Skates have weak electric organs.Wnt Proteins: Wnt proteins are a large family of secreted glycoproteins that play essential roles in EMBRYONIC AND FETAL DEVELOPMENT, and tissue maintenance. They bind to FRIZZLED RECEPTORS and act as PARACRINE PROTEIN FACTORS to initiate a variety of SIGNAL TRANSDUCTION PATHWAYS. The canonical Wnt signaling pathway stabilizes the transcriptional coactivator BETA CATENIN.Insects: 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)Retina: The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Mice, Inbred C57BLCentral Nervous System: The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Goldfish: Common name for Carassius auratus, a type of carp (CARPS).Caenorhabditis elegans: A species of nematode that is widely used in biological, biochemical, and genetic studies.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Ranidae: The family of true frogs of the order Anura. The family occurs worldwide except in Antarctica.Urodela: An order of the Amphibia class which includes salamanders and newts. They are characterized by usually having slim bodies and tails, four limbs of about equal size (except in Sirenidae), and a reduction in skull bones.Trans-Activators: Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.Opsins: Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.Anura: An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.Paired Box Transcription Factors: A family of transcription factors that control EMBRYONIC DEVELOPMENT within a variety of cell lineages. They are characterized by a highly conserved paired DNA-binding domain that was first identified in DROSOPHILA segmentation genes.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Bone Morphogenetic Proteins: Bone-growth regulatory factors that are members of the transforming growth factor-beta superfamily of proteins. They are synthesized as large precursor molecules which are cleaved by proteolytic enzymes. The active form can consist of a dimer of two identical proteins or a heterodimer of two related bone morphogenetic proteins.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Repressor Proteins: Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.Genomics: The systematic study of the complete DNA sequences (GENOME) of organisms.Animal Fins: Membranous appendage of fish and other aquatic organisms used for locomotion or balance.Organizers, Embryonic: Cells in certain regions of an embryo that self-regulate embryonic development. These organizers have been found in dorsal and ventral poles of GASTRULA embryos, including Spemann organizer in amphibians, and Hensen node in chicken and mouse. These organizer cells communicate with each other via a network of secreted signaling proteins, such as BONE MORPHOGENETIC PROTEINS and their antagonists (chordin and noggin).Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Notochord: A cartilaginous rod of mesodermal cells at the dorsal midline of all CHORDATE embryos. In lower vertebrates, notochord is the backbone of support. In the higher vertebrates, notochord is a transient structure, and segments of the vertebral column will develop around it. Notochord is also a source of midline signals that pattern surrounding tissues including the NEURAL TUBE development.Head: 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.Integration Host Factors: Bacterial proteins that are used by BACTERIOPHAGES to incorporate their DNA into the DNA of the "host" bacteria. They are DNA-binding proteins that function in genetic recombination as well as in transcriptional and translational regulation.Eye ProteinsIntrons: Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.Developmental Biology: The field of biology which deals with the process of the growth and differentiation of an organism.Parasites: Invertebrate organisms that live on or in another organism (the host), and benefit at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Limb Buds: Distinct regions of mesenchymal outgrowth at both flanks of an embryo during the SOMITE period. Limb buds, covered by ECTODERM, give rise to forelimb, hindlimb, and eventual functional limb structures. Limb bud cultures are used to study CELL DIFFERENTIATION; ORGANOGENESIS; and MORPHOGENESIS.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.HeLa Cells: The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.Nuclear Proteins: Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.Rod Opsins: Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.Alligators and Crocodiles: Large, long-tailed reptiles, including caimans, of the order Loricata.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Carps: Common name for a number of different species of fish in the family Cyprinidae. This includes, among others, the common carp, crucian carp, grass carp, and silver carp.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Dogfish: Sharks of the family Squalidae, also called dogfish sharks. They comprise at least eight genera and 44 species. Their LIVER is valued for its oil and its flesh is often made into fertilizer.Oncorhynchus mykiss: A large stout-bodied, sometimes anadromous, TROUT found in still and flowing waters of the Pacific coast from southern California to Alaska. It has a greenish back, a whitish belly, and pink, red, or lavender stripes on the sides, with usually a sprinkling of black dots. It is highly regarded as a sport and food fish. Its former name was Salmo gairdneri. The sea-run rainbow trouts are often called steelheads. Redband trouts refer to interior populations of rainbows.
  • It was thought collagen was a relatively recent invention in vertebrate evolution that unites us with reptiles, amphibians, sharks and bony fishes, while the lamprey skeleton was based on quite different proteins," said Martin Cohn, Ph.D., a developmental biologist and associate professor with the UF departments of zoology and anatomy and cell biology. (bio-medicine.org)
  • Background: Arthropod vectors of disease may encounter more than one infected host during the course of their lifetime. (elsevier.com)
  • As occurs with hosts, not all infected vectors transmit the virus efficiently, but just those in which the virus replicates systemically and reach enough virus levels in the salivary glands to enable transmission after biting the host. (mdpi.com)
  • Although considerable knowledge is available regarding the mammalian hosts infected by T. cruzi in this wetland, no studies have investigated its vectors in this region. (bvsalud.org)
  • The most common hosts for St. Louis encephalitis virus were also the most common hosts for WNV, which strongly supports the role of similar vectors for both flaviviruses. (ajtmh.org)
  • In addition to arbovirus interactions with vectors, we study interactions of arboviruses with vertebrate cells. (gla.ac.uk)
  • Here, an implication of multiplicity is discussed, with focus on an ultraviolet-sensitive non-visual opsin-parapinopsin-that underlies pineal wavelength discrimination in lower vertebrates. (frontiersin.org)
  • In addition, chapters focus on mechanisms of development and immunodefenses in protostome and deuterostome and lower vertebrates. (nhbs.com)
  • However, the identification of the microbial taxa is only the first step toward the understanding of host-microbiota interactions. (frontiersin.org)
  • The focus of this initiative is to encourage studies to discover novel genetic paradigms that may account for the interactions between the virus, the host, and the therapeutic drugs in the central nervous system (CNS) that result in the pathogenesis, progression, and clinical manifestations of HAND. (nih.gov)
  • However, few studies have examined rates of transmission from infected hosts to uninfected ticks, a trait known as the reservoir competence of these hosts. (cdc.gov)
  • Ticks feeding on hosts were allowed to feed to repletion and drop from hosts into the pans, from which they were collected. (cdc.gov)
  • Hosts that had been infested were held for an additional 4 days, and engorged ticks were collected each day. (cdc.gov)
  • They re transmitted to vertebrate hosts with the help of ixodid ticks that are in the nymph stage. (medindia.net)
  • To determine the genetic source of these differences, genome sequences from representative strains (from humans, pigs, chickens, and rodents) and genomic microarrays were used to identify host-specific genes tied to ecological success in vivo . (unl.edu)
  • Instead of leaving their host to forage, these fish spend their lives inside the sea cucumber's body, biting off pieces of their host's gills and gonads whenever they get hungry. (sciencemadecool.com)
  • Vertebrate Reservoirs of Arboviruses: Myth, Synonym of Amplifier, or Reality? (mdpi.com)
  • This review addresses controversial issues concerning vertebrate reservoirs and their role in arbovirus persistence in nature, examines the genesis of the problem from a historical perspective, discusses various unresolved issues from multiple points of view, assesses the present status of the notion in light of current knowledge, and provides options for a solution to resolve the issue. (mdpi.com)
  • To determine whether the observed host specificity of rodent associated L. reuteri in mice extended to other host-associated lineages, a crossover human experimental trial was conducted. (unl.edu)
  • Molecular evolution of dmrt1 promoters for germ and somatic cells in vertebrate gonads is shown. (phys.org)
  • But little is known about the how the DMRT1 gene is turned on and off in vertebrate testicular somatic cells or germ cells. (phys.org)
  • The research team proposed a new model of the key mechanism behind transcriptional regulation of dmrt1 in germ and somatic cells by these promoters and three conserved noncoding sequences during vertebrate evolution. (phys.org)
  • In jawed vertebrates, somatic hypermutagenesis occurs in the variable regions of immunoglobulin genes, leading to affinity maturation of antibodies. (deepdyve.com)
  • In order to determine the importance of climatic, landscape and host-related factors affecting BTV diffusion across Europe, we fitted different phylogeographic models to a dataset of 113 time-stamped and geo-referenced BTV genomes, representing multiple strains and serotypes. (nottingham.ac.uk)
  • The inactivity of vertebrate DNA has been attributed in part to suppression of CpG in vertebrate genomes to ∼23% of random frequency ( 4 ). (jimmunol.org)
  • During vertebrate evolution, transposable elements have repeatedly contributed regulatory and coding sequences to the host, leading to the emergence of new lineage-specific gene regulations and functions. (springer.com)
  • But the fundamental reason why the researchers did not anticipate this complex interaction was because of their assumption that evolution is the source of any such "congruence between host and symbiont population structures. (icr.org)
  • Despite the presence of the endogenous microbiota limiting EHEC colonization levels, EHEC colonization and virulence can be studied either under gnotobiotic conditions or against the backdrop of an endogenous (and variable) host microbiota. (glos.ac.uk)
  • The classical and alternative complement pathways are important in Borrelia eradication by the vertebrate host. (prohealth.com)
  • Avian host and mosquito (Diptera: Culicidae) vector competence determine the efficiency of West Nile and St. Louis encephalitis virus transmission. (ajtmh.org)
  • The vertebrates possess unique adaptations for immune defense that have apparently evolved gradually over the long evolutionary history of the vertebrate lineage. (els.net)
  • The National Institute of Mental Health (NIMH) and The National Institute of Neurological Disorders and Stroke (NINDS) solicit research grant applications to supp ort studies focused on viral and host genetic factors involved in HIV-1 Associated Neurocognitive Disorders (HAND) in the setting of highly active anti-retroviral therapy (HAART). (nih.gov)
  • The use of state-of-the-art genetic approaches (including transcriptomics, phenomics, epigenomics, whole genome association studies, next generation sequ encing, exome sequencing, & systems biology) to identify and validate (including in vitro models, animal models, & human samples) viral and host genetic factors which influence the pathophysiology of HAND are encouraged. (nih.gov)
  • The book begins with descriptions of the biology of gastrointestinal nematodes, the harm they cause to the host and their economic impact. (wiley.com)
  • that feed more opportunistically on both avian and mammalian hosts may be important in epidemic/epizootic transmission under certain conditions. (springer.com)
  • Taken together, these observations indicate that transposable elements are major drivers of genomic and biological diversity in vertebrates, with possible important roles in speciation and major evolutionary transitions. (springer.com)
  • Investigating the unique mode of vector-borne transmission requires a clear understanding of the roles of vertebrates. (mdpi.com)
  • Dynamic and complex inter-relationships among virus, vector, and vertebrate host, integrated with environmental factors, determine the intensity of virus transmission. (wadsworth.org)