Bombyx. Medical search

Insect Proteins: Proteins found in any species of insect.Fibroins: Fibrous proteins secreted by INSECTS and SPIDERS. Generally, the term refers to silkworm fibroin secreted by the silk gland cells of SILKWORMS, Bombyx mori. Spider fibroins are called spidroins or dragline silk fibroins.Silk: A continuous protein fiber consisting primarily of FIBROINS. It is synthesized by a variety of INSECTS and ARACHNIDS.Nucleopolyhedrovirus: A genus of the family BACULOVIRIDAE, subfamily Eubaculovirinae, characterized by the formation of crystalline, polyhedral occlusion bodies in the host cell nucleus. The type species is Autographa californica nucleopolyhedrovirus.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Sericins: A serine-rich sticky protein secreted by MOTHS. Generally, the term refers to silkworm silk gum protein secreted in the middle section of silk gland cells of SILKWORMS, Bombyx mori. Sericin acts as a cement and coating for the two fibroin filaments in a silk strand and is readily soluble in mild alkaline solution.Hemolymph: The blood/lymphlike nutrient fluid of some invertebrates.Insect Hormones: Hormones secreted by insects. They influence their growth and development. Also synthetic substances that act like insect hormones.Pupa: An inactive stage between the larval and adult stages in the life cycle of insects.Genes, Insect: The functional hereditary units of INSECTS.Exocrine Glands: Glands of external secretion that release its secretions to the body's cavities, organs, or surface, through a duct.Morus: A plant genus of the family MORACEAE that is widely planted for shade.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.Molting: Periodic casting off FEATHERS; HAIR; or cuticle. Molting is a process of sloughing or desquamation, especially the shedding of an outer covering and the development of a new one. This phenomenon permits growth in ARTHROPODS, skin renewal in AMPHIBIANS and REPTILES, and the shedding of winter coats in BIRDS and MAMMALS.Ecdysteroids: Steroids that bring about MOLTING or ecdysis in insects. Ecdysteroids include the endogenous insect hormones (ECDYSONE and ECDYSTERONE) and the insect-molting hormones found in plants, the phytoecdysteroids. Phytoecdysteroids are natural insecticides.Fat Body: A nutritional reservoir of fatty tissue found mainly in insects and amphibians.Metamorphosis, Biological: 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.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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Moths: Insects of the suborder Heterocera of the order LEPIDOPTERA.Diapause, Insect: Seasonal suspension of insect growth development. It can be either induced by environmental cues (e.g., PHOTOPERIOD) or as a facultative part of the life cycle in order to time development with seasonal changes.RNA, Transfer, Gly: A transfer RNA which is specific for carrying glycine to sites on the ribosomes in preparation for protein synthesis.Juvenile Hormones: Compounds, either natural or synthetic, which block development of the growing insect.Genome, Insect: The genetic complement of an insect (INSECTS) as represented in its DNA.Lepidoptera: A large order of insects comprising the butterflies and moths.Alanine-tRNA Ligase: An enzyme that activates alanine with its specific transfer RNA. EC 6.1.1.7.Baculoviridae: Family of INSECT VIRUSES containing two subfamilies: Eubaculovirinae (occluded baculoviruses) and Nudibaculovirinae (nonoccluded baculoviruses). The Eubaculovirinae, which contain polyhedron-shaped inclusion bodies, have two genera: NUCLEOPOLYHEDROVIRUS and GRANULOVIRUS. Baculovirus vectors are used for expression of foreign genes in insects.Ecdysterone: A steroid hormone that regulates the processes of MOLTING or ecdysis in insects. Ecdysterone is the 20-hydroxylated ECDYSONE.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.Glycine-tRNA Ligase: An enzyme that activates glycine with its specific transfer RNA. EC 6.1.1.14.Fatty Alcohols: Usually high-molecular-weight, straight-chain primary alcohols, but can also range from as few as 4 carbons, derived from natural fats and oils, including lauryl, stearyl, oleyl, and linoleyl alcohols. They are used in pharmaceuticals, cosmetics, detergents, plastics, and lube oils and in textile manufacture. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Densovirus: A genus of PARVOVIRIDAE, subfamily DENSOVIRINAE, comprising helper-independent viruses containing only two species. Junonia coenia densovirus is the type species.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.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.Moraceae: The mulberry plant family of the order Urticales, subclass Hamamelidae, class Magnoliopsida. They have milky latex and small, petalless male or female flowers.Sex Attractants: Pheromones that elicit sexual attraction or mating behavior usually in members of the opposite sex in the same species.Sebaceous Glands: Small, sacculated organs found within the DERMIS. Each gland has a single duct that emerges from a cluster of oval alveoli. Each alveolus consists of a transparent BASEMENT MEMBRANE enclosing epithelial cells. The ducts from most sebaceous glands open into a HAIR FOLLICLE, but some open on the general surface of the SKIN. Sebaceous glands secrete SEBUM.Bacillus thuringiensis: A species of gram-positive bacteria which may be pathogenic for certain insects. It is used for the biological control of the Gypsy moth.Pheromones: Chemical substances, excreted by an organism into the environment, that elicit behavioral or physiological responses from other organisms of the same species. Perception of these chemical signals may be olfactory or by contact.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.Neuropeptides: Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.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.Alkadienes: Acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds.Insect Viruses: Viruses infecting insects, the largest family being BACULOVIRIDAE.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)Hemolysin Proteins: Proteins from BACTERIA and FUNGI that are soluble enough to be secreted to target ERYTHROCYTES and insert into the membrane to form beta-barrel pores. Biosynthesis may be regulated by HEMOLYSIN FACTORS.Chromosomes, Insect: Structures within the CELL NUCLEUS of insect cells containing DNA.Expressed Sequence Tags: Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.Ecdysone: A steroid hormone that regulates the processes of MOLTING or ecdysis in insects.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Vitellins: Major egg yolk proteins from egg-laying animals such as non-mammalian VERTEBRATES; ARTHROPODS; and others. They are high-density lipoglycoproteins derived from circulating precursors, VITELLOGENINS. Vitellins serve as nutrients for the growing non-mammalian embryos (EMBRYO, NONMAMMALIAN).Antigens, CD13: Zinc-binding metalloproteases that are members of the type II integral membrane metalloproteases. They are expressed by GRANULOCYTES; MONOCYTES; and their precursors as well as by various non-hematopoietic cells. They release an N-terminal amino acid from a peptide, amide or arylamide.Endotoxins: Toxins closely associated with the living cytoplasm or cell wall of certain microorganisms, which do not readily diffuse into the culture medium, but are released upon lysis of the cells.Chromosomes, Artificial, Bacterial: DNA constructs that are composed of, at least, a REPLICATION ORIGIN, for successful replication, propagation to and maintenance as an extra chromosome in bacteria. In addition, they can carry large amounts (about 200 kilobases) of other sequence for a variety of bioengineering purposes.Hemocytes: Any blood or formed element especially in invertebrates.Viral Structural Proteins: Viral proteins that are components of the mature assembled VIRUS PARTICLES. They may include nucleocapsid core proteins (gag proteins), enzymes packaged within the virus particle (pol proteins), and membrane components (env proteins). These do not include the proteins encoded in the VIRAL GENOME that are produced in infected cells but which are not packaged in the mature virus particle,i.e. the so called non-structural proteins (VIRAL NONSTRUCTURAL PROTEINS).Tribolium: A genus of small beetles of the family Tenebrionidae; T. confusum is the "confused flour beetle".Digestive System: A group of organs stretching from the MOUTH to the ANUS, serving to breakdown foods, assimilate nutrients, and eliminate waste. In humans, the digestive system includes the GASTROINTESTINAL TRACT and the accessory glands (LIVER; BILIARY TRACT; PANCREAS).Chorion: The outermost extra-embryonic membrane surrounding the developing embryo. In REPTILES and BIRDS, it adheres to the shell and allows exchange of gases between the egg and its environment. In MAMMALS, the chorion evolves into the fetal contribution of the PLACENTA.Genetic Enhancement: The use of genetic methodologies to improve functional capacities of an organism rather than to treat disease.Imino Furanoses: Five-carbon furanose sugars in which the OXYGEN is replaced by a NITROGEN atom.Sense Organs: Specialized organs adapted for the reception of stimuli by the NERVOUS SYSTEM.Ovum: A mature haploid female germ cell extruded from the OVARY at OVULATION.Egg Proteins: Proteins which are found in eggs (OVA) from any species.Retroelements: Elements that are transcribed into RNA, reverse-transcribed into DNA and then inserted into a new site in the genome. Long terminal repeats (LTRs) similar to those from retroviruses are contained in retrotransposons and retrovirus-like elements. Retroposons, such as LONG INTERSPERSED NUCLEOTIDE ELEMENTS and SHORT INTERSPERSED NUCLEOTIDE ELEMENTS do not contain LTRs.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.Open Reading Frames: A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).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.Laboratory Chemicals: Chemicals necessary to perform experimental and/or investigative procedures and for the preparation of drugs and other chemicals.Catechol Oxidase: An enzyme of the oxidoreductase class that catalyzes the reaction between catechol and oxygen to yield benzoquinone and water. It is a complex of copper-containing proteins that acts also on a variety of substituted catechols. EC 1.10.3.1.Corpora Allata: Paired or fused ganglion-like bodies in the head of insects. The bodies secrete hormones important in the regulation of metamorphosis and the development of some adult tissues.Viral Proteins: Proteins found in any species of virus.Chitinase Fractional Precipitation: A method which uses specific precipitation reactions to separate or collect substances from a solution.Spodoptera: A genus of owlet moths of the family Noctuidae. These insects are used in molecular biology studies during all stages of their life cycle.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.Sex Chromosomes: The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)Reoviridae: A family of unenveloped RNA viruses with cubic symmetry. The twelve genera include ORTHOREOVIRUS; ORBIVIRUS; COLTIVIRUS; ROTAVIRUS; Aquareovirus, Cypovirus, Phytoreovirus, Fijivirus, Seadornavirus, Idnoreovirus, Mycoreovirus, and Oryzavirus.Tymoviridae: A family of icosahedral, non-enveloped, RNA plant viruses comprised of three genera: TYMOVIRUS, Marafivirus and Maculavirus.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.Heavy Ions: Positively-charged atomic nuclei that have been stripped of their electrons. These particles have one or more units of electric charge and a mass exceeding that of the Helium-4 nucleus (alpha particle).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.Molecular Weight: The sum of the weight of all the atoms in a molecule.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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Benzoic Acid: A fungistatic compound that is widely used as a food preservative. It is conjugated to GLYCINE in the liver and excreted as hippuric acid.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Arthropod Antennae: Paired sense organs connected to the anterior segments of ARTHROPODS that help them navigate through the environment.Bacopa: A plant genus of the family Plantaginaceae. Members contain bacopaside, bacopasaponins and other dammarane type jujubogenins.Manduca: A genus of sphinx or hawk moths of the family Sphingidae. These insects are used in molecular biology studies during all stages of their life cycle.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.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).beta-N-Acetyl-Galactosaminidase: A hexosiminidase that specifically hydrolyzes terminal non-reducing N-acetyl-D-galactosamine residues in N-acetyl-beta-D-galactosaminides.Vitellogenesis: The active production and accumulation of VITELLINS (egg yolk proteins) in the non-mammalian OOCYTES from circulating precursors, VITELLOGENINS. Vitellogenesis usually begins after the first MEIOSIS and is regulated by estrogenic hormones.Animals, Genetically Modified: ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.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.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.Inclusion Bodies, Viral: An area showing altered staining behavior in the nucleus or cytoplasm of a virus-infected cell. Some inclusion bodies represent "virus factories" in which viral nucleic acid or protein is being synthesized; others are merely artifacts of fixation and staining. One example, Negri bodies, are found in the cytoplasm or processes of nerve cells in animals that have died from rabies.Random Amplified Polymorphic DNA Technique: Technique that utilizes low-stringency polymerase chain reaction (PCR) amplification with single primers of arbitrary sequence to generate strain-specific arrays of anonymous DNA fragments. RAPD technique may be used to determine taxonomic identity, assess kinship relationships, analyze mixed genome samples, and create specific probes.Receptors, Odorant: Proteins, usually projecting from the cilia of olfactory receptor neurons, that specifically bind odorant molecules and trigger responses in the neurons. The large number of different odorant receptors appears to arise from several gene families or subfamilies rather than from DNA rearrangement.Sf9 Cells: Cell line derived from SF21 CELLS which are a cell line isolated from primary explants of SPODOPTERA FRUGIPERDA pupal tissue.Chymotrypsin: A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.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.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.DNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.RNA, Transfer: The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.Formycins: Pyrazolopyrimidine ribonucleosides isolated from Nocardia interforma. They are antineoplastic antibiotics with cytostatic properties.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.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.POU Domain Factors: A family of transcription factors characterized by the presence of a bipartite DNA-binding domain known as the POU domain. The POU domain contains two subdomains, a POU-specific domain and a POU-homeodomain. The POU domain was originally identified as a region of approximately 150 amino acids shared between the Pit-1, Oct-1, Oct-2, and Unc-86 transcription factors.Genetic Vectors: DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.Malpighian Tubules: Slender tubular or hairlike excretory structures found in insects. They emerge from the alimentary canal between the mesenteron (midgut) and the proctodeum (hindgut).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.Embryo, Nonmammalian: The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.Chromatography, Ion Exchange: Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.Tissue Distribution: Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.Bacterial Toxins: Toxic substances formed in or elaborated by bacteria; they are usually proteins with high molecular weight and antigenicity; some are used as antibiotics and some to skin test for the presence of or susceptibility to certain diseases.Pigmentation: Coloration or discoloration of a part by a pigment.Introns: Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.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.Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.Diptera: An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).Antimicrobial Cationic Peptides: Small cationic peptides that are an important component, in most species, of early innate and induced defenses against invading microbes. In animals they are found on mucosal surfaces, within phagocytic granules, and on the surface of the body. They are also found in insects and plants. Among others, this group includes the DEFENSINS, protegrins, tachyplesins, and thionins. They displace DIVALENT CATIONS from phosphate groups of MEMBRANE LIPIDS leading to disruption of the membrane.Melanins: Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration.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, Viral: The functional hereditary units of VIRUSES.RNA, Ribosomal: The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)Spiders: 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)Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Endocrine Glands: Ductless glands that secrete HORMONES directly into the BLOOD CIRCULATION. These hormones influence the METABOLISM and other functions of cells in the body.Pest Control, Biological: Use of naturally-occuring or genetically-engineered organisms to reduce or eliminate populations of pests.1-Deoxynojirimycin: An alpha-glucosidase inhibitor with antiviral action. Derivatives of deoxynojirimycin may have anti-HIV activity.Repetitive Sequences, Nucleic Acid: Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Butterflies: Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Fushi Tarazu Transcription Factors: Fushi tarazu transcription factors were originally identified in DROSOPHILA. They are found throughout ARTHROPODS and play important roles in segmentation and CENTRAL NERVOUS SYSTEM development.RNA Interference: A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Salivary Glands: Glands that secrete SALIVA in the MOUTH. There are three pairs of salivary glands (PAROTID GLAND; SUBLINGUAL GLAND; SUBMANDIBULAR GLAND).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.Gene Expression Regulation, Viral: Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.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.Receptors, Steroid: Proteins found usually in the cytoplasm or nucleus that specifically bind steroid hormones and trigger changes influencing the behavior of cells. The steroid receptor-steroid hormone complex regulates the transcription of specific genes.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Wing Biotechnology: Body of knowledge related to the use of organisms, cells or cell-derived constituents for the purpose of developing products which are technically, scientifically and clinically useful. Alteration of biologic function at the molecular level (i.e., GENETIC ENGINEERING) is a central focus; laboratory methods used include TRANSFECTION and CLONING technologies, sequence and structure analysis algorithms, computer databases, and gene and protein structure function analysis and prediction.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.Green Fluorescent Proteins: Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.Amplified Fragment Length Polymorphism Analysis: The detection of RESTRICTION FRAGMENT LENGTH POLYMORPHISMS by selective PCR amplification of restriction fragments derived from genomic DNA followed by electrophoretic analysis of the amplified restriction fragments.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Base Composition: The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.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.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Lethal Dose 50: The dose amount of poisonous or toxic substance or dose of ionizing radiation required to kill 50% of the tested population.Bees: 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.Trypsin Inhibitors: Serine proteinase inhibitors which inhibit trypsin. They may be endogenous or exogenous compounds.Databases, Genetic: Databases devoted to knowledge about specific genes and gene products.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.Genomics: The systematic study of the complete DNA sequences (GENOME) of organisms.Gene Knockout Techniques: Techniques to alter a gene sequence that result in an inactivated gene, or one in which the expression can be inactivated at a chosen time during development to study the loss of function of a gene.Amino Acyl-tRNA Synthetases: A subclass of enzymes that aminoacylate AMINO ACID-SPECIFIC TRANSFER RNA with their corresponding AMINO ACIDS.Breeding: The production of offspring by selective mating or HYBRIDIZATION, GENETIC in animals or plants.DNA Restriction Enzymes: Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.Monophenol Monooxygenase: An enzyme of the oxidoreductase class that catalyzes the reaction between L-tyrosine, L-dopa, and oxygen to yield L-dopa, dopaquinone, and water. It is a copper protein that acts also on catechols, catalyzing some of the same reactions as CATECHOL OXIDASE. EC 1.14.18.1.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.RNA: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Bacterial Proteins: Proteins found in any species of bacterium.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Protein Structure, Secondary: The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Receptors, Cell Surface: Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Blotting, Northern: Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.Endonucleases: Enzymes that catalyze the hydrolysis of the internal bonds and thereby the formation of polynucleotides or oligonucleotides from ribo- or deoxyribonucleotide chains. EC 3.1.-.Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.Olfactory Receptor Neurons: Neurons in the OLFACTORY EPITHELIUM with proteins (RECEPTORS, ODORANT) that bind, and thus detect, odorants. These neurons send their DENDRITES to the surface of the epithelium with the odorant receptors residing in the apical non-motile cilia. Their unmyelinated AXONS synapse in the OLFACTORY BULB of the BRAIN.Alternative Splicing: A process whereby multiple RNA transcripts are generated from a single gene. Alternative splicing involves the splicing together of other possible sets of EXONS during the processing of some, but not all, transcripts of the gene. Thus a particular exon may be connected to any one of several alternative exons to form a mature RNA. The alternative forms of mature MESSENGER RNA produce PROTEIN ISOFORMS in which one part of the isoforms is common while the other parts are different.Genetic Linkage: The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.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.Organ Specificity: Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.Oogenesis: The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)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.Chromosomes: In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Protein 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.Exons: The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.DNA Probes: Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.Genome: The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Circular Dichroism: A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Time Factors: Elements of limited time intervals, contributing to particular results or situations.Viral Plaque Assay: Method for measuring viral infectivity and multiplication in CULTURED CELLS. Clear lysed areas or plaques develop as the VIRAL PARTICLES are released from the infected cells during incubation. With some VIRUSES, the cells are killed by a cytopathic effect; with others, the infected cells are not killed but can be detected by their hemadsorptive ability. Sometimes the plaque cells contain VIRAL ANTIGENS which can be measured by IMMUNOFLUORESCENCE.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Kinetics: The rate dynamics in chemical or physical systems.

The biosynthesis of transfer RNA in insects. II. Isolation of transfer RNA precursors from the posterior silk gland of Bombyx mori. (1/1272)

The occurrence of precursors to tRNA in the post-polysomal fraction of the posterior silk gland of Bombyx mori was demonstrated by pulse-chase labeling and DNA-RNA hybridization competition experiments. These precursors had molecular sizes ranging from 4S to 5S on polyacrylamide gel electrophoresis. Analysis of the incorporation of the methyl group from [methyl-14C]methionine revealed that a radioactive peak on polyacrylamide gel appeared in the 4.5S region during brief labeling. This suggested that some methylation occurred at the 4.5S precursor step. (+info)

Comparison of Bombyx mori and Helicoverpa armigera cytoplasmic actin genes provides clues to the evolution of actin genes in insects. (2/1272)

The cytoplasmic actin genes BmA3 and BmA4 of Bombyx mori were found clustered in a single genomic clone in the same orientation. As a similar clustering of the two cytoplasmic actin genes Ha3a and Ha3b also occurs in another lepidopteran, Helicoverpa armigera, we analyzed the sequence of the pair of genes from each species. Due to the high conservation of cytoplasmic actins, the coding sequence of the four genes was easily aligned, allowing the detection of similarities in noncoding exon and intron sequences as well as in flanking sequences. All four genes exhibited a conserved intron inserted in codon 117, an original position not encountered in other species. It can thus be postulated that all of these genes derived from a common ancestral gene carrying this intron after a single event of insertion. The comparison of the four genes revealed that the genes of B. mori and H. armigera are related in two different ways: the coding sequence and the intron that interrupts it are more similar between paralogous genes within each species than between orthologous genes of the two species. In contrast, the other (noncoding) regions exhibited the greatest similarity between a gene of one species and a gene of the other species, defining two pairs of orthologous genes, BmA3 and HaA3a on one hand and BmA4 and HaA3b on the other. However, in each species, the very high similarities of the coding sequence and of the single intron that interrupts it strongly suggest that gene conversion events have homogenized this part of the sequence. As the divergence of the B. mori genes was higher than that of the H. armigera genes, we postulated that the gene conversion occurred earlier in the B. mori lineage. This leads us to hypothesize that gene conversion could also be responsible for the original transfer of the common intron to the second gene copy before the divergence of the B. mori and H. armigera lineages. (+info)

Active transport of calcium across the isolated midgut of Hyalophora cecropia. (3/1272)

1. The net flux of 45Ca from lumen to blood side across the isolated and short-circuited Cecropia midgut was 1-9 +/- 0-2 muequiv. cm-2h-1 in 8 mM Ca and the flux ratio was as high as 56 to 1. 2. The calcium influx was depressed by anoxia; 73% after 30 min. 3. The kinetics of Ca transport were anomalous; the apparent Km varied with Ca concentration from less than 0-2 to greater than 5-6 mM Ca and the apparent Vmax varied from less than 1-3 to greater than 3-3 muequiv. cm-2h-1. 4. The calcium influx showed a delay before the tracer steady state was attained, indicating the existence in the transport route of a calcium pool equivalent to 5-7 muequiv/g. wet weight of midgut tissue. 5 High calcium (16 mM) depressed the short-circuit current and potassium transport from blood to lumen side across the midgut. 6. Calcium depressed magnesium transport, from lumen to blood side across the midgut, and magnesium depressed the calcium transport. 7. Ca transport by the midgut does not regulate the Ca level in the haemolymph in vivo; it merely aids the diffusion of calcium down its electrochemical gradient. However, Ca transport may assist the uptake of the nutrients from the midgut contents. (+info)

Prophenoloxidase-activating enzyme of the silkworm, Bombyx mori. Purification, characterization, and cDNA cloning. (4/1272)

Prophenoloxidase-activating enzyme (PPAE) was purified to homogeneity as judged by SDS-polyacrylamide gel electrophoresis from larval cuticles of the silkworm, Bombyx mori. The purified PPAE preparation was shown to be a mixture of the isozymes of PPAE (PPAE-I and PPAE-II), which were eluted at different retention times in reversed-phase high performance liquid chromatography. PPAE-I and PPAE-II seemed to be post translationally modified isozymes and/or allelic variants. Both PPAE isozymes were proteins composed of two polypeptides (heavy and light chains) that are linked by disulfide linkage(s) and glycosylated serine proteases. The results of cDNA cloning, peptide mapping, and amino acid sequencing of PPAE revealed that PPAE is synthesized as prepro-PPAE with 441 amino acid residues and is activated from pro-PPAE by cleavage of a peptide bond between Lys152 and Ile153. The homology search showed 36.9% identity of PPAE to easter, which is a serine protease involved in dorso-ventral pattern formation in the Drosophila embryo, and indicated the presence of two consecutive clip-like domains in the light chain. A single copy of the PPAE gene was suggested to be present in the silkworm genome. In the fifth instar larvae, PPAE transcripts were detected in the integument, hemocytes, and salivary glands but not in the fat body or mid gut. A polypeptide cross-reactive to mono-specific anti-PPAE/IgG was transiently detected in the extract of eggs between 1 and 3 h after they were laid. (+info)

Gene targeting in the silkworm by use of a baculovirus. (5/1272)

The Bombyx mori fibroin light (L)-chain gene was cloned and the green fluorescent protein (GFP) gene inserted into exon 7. The chimeric L-chain-GFP gene was used to replace the polyhedrin gene of Autographa californica nucleopolyhedrovirus (AcNPV). This recombinant virus was used to target the L-chain-GFP gene to the L-chain region of the silkworm genome. Female moths were infected with the recombinant virus and then mated with normal male moths. Genomic DNA from their progenies was screened for the desired targeting event. This analysis showed that the chimeric gene had integrated into the L-chain gene on the genome by homologous recombination and was stably transmitted through generations. The chimeric gene was expressed in the posterior silk gland, and the gene product was spun into the cocoon layer. (+info)

Characterization of the 25K FP gene of the baculovirus Bombyx mori nucleopolyhedrovirus: implications for post-mortem host degradation. (6/1272)

Mutagenesis experiments on the baculovirus Bombyx mori nucleopolyhedrovirus (BmNPV) using 5-bromo-2'-deoxyuridine generated five mutants with a 'few polyhedra' (FP) phenotype. Sequence analysis of the 25K gene homologue of the BmNPV FP mutants revealed nucleotide substitutions in the coding region. Rescue experiments indicated that the FP phenotype of the BmNPV mutants resulted from mutations in the 25K coding region. Effects of infection by these FP mutants were analysed following injection of the viruses into silkworm (B. mori) larvae. Compared to infection with wild-type virus, infection with each FP mutant resulted in reduced host degradation (liquefaction). The degree to which liquefaction was blocked corresponded to the degree of functional disruption of the 25K gene product and to the extent to which polyhedron production was reduced. Electron microscopy revealed that (1) polyhedron production was reduced, (2) very few virions were occluded and those that were lacked envelopes, and (3) the basal lamina of fat-body tissue was not destroyed by infection and accumulations of virions occurred along the membrane. Typical NPV-induced liquefaction was observed following infection with a polyhedrin deletion mutant, indicating that host degradation was not related to polyhedron production. These results suggest that (1) the 25K gene product is involved in the host degradation process caused by virus infection and (2) the FP phenotype is an indirect result of disruption of the 25K gene; activation or suppression of a specific host or viral gene related to tissue degradation and polyhedron formation may be involved. (+info)

Studies on silk fibroin of Bombyx mori. I. Fractionation of fibroin prepared from the posterior silk gland. (7/1272)

1. Fractionation of fibroin prepared from the posterior silk glands of Bombyx mori was carried out. After carboxymethylation of the fibroin, it was fractionated by ammonium sulfate precipitation, Sephadex G-200 gel filtration and DEAE-cellulose column chromatography. 2. The fibroin was composed of at least two protein groups of large molecular size and three or four components of small molecular size, and, in addition, a mixture of proteins ranging in size from about 25,000 to more than 100,000 daltons with almost the same amino acid compositions. 3. The latter proteins contained about 48% glycine, 32% alanine, 11% serine, 4.5% tyrosine, 2% valine, and other minor amino acids. The sum of these main five amino acids accounts for more than 97% of the total amino acid residues of the proteins. 4. The present results indicate major heterogeneity in the molecular size of posterior silk gland fibroin, and, in addition, suggest the possibility of repeating sequences with relatively simple amino acid compositions in major peptide chains of fibroin. (+info)

A TATA element is required for tRNA promoter activity and confers TATA-binding protein responsiveness in Drosophila Schneider-2 cells. (8/1272)

In contrast to yeast and mammalian systems, which depend principally on internal promoter elements for tRNA gene transcription, insect systems require additional upstream sequences. To understand the function of the upstream sequences, we have asked whether the Bombyx mori tRNACAla and tRNASGAla genes, which are absolutely dependent on these sequences in vitro, also require them for transcription in vivo. We introduced wild-type and mutant versions of the Bombyx tRNAAla genes into Drosophila Schneider-2 cells and found that the tRNACAla gene is efficiently transcribed and that its transcription depends strongly on the distal segment of its upstream promoter. In contrast, the tRNASGAla gene is inefficiently transcribed, and this inefficiency results from lack of a specific sequence within the distal tRNACAla upstream promoter. This sequence, 5'-TTTATAT-3', is sufficient to increase the activity of the tRNASGAla promoter to that of the tRNACAla promoter. Moreover, promoters containing the 5'-TTTATAT-3' element are stimulated by increased levels of cellular TATA-binding protein. Together these results indicate that, in insect cells, a TATA-like element is specifically required to form functional TATA-binding protein-containing complexes that promote efficient transcription of tRNA genes. (+info)

The biosynthesis of transfer RNA in insects. II. Isolation of transfer RNA precursors from the posterior silk gland of Bombyx mori. (1/1272)

Comparison of Bombyx mori and Helicoverpa armigera cytoplasmic actin genes provides clues to the evolution of actin genes in insects. (2/1272)

Active transport of calcium across the isolated midgut of Hyalophora cecropia. (3/1272)

Prophenoloxidase-activating enzyme of the silkworm, Bombyx mori. Purification, characterization, and cDNA cloning. (4/1272)

Gene targeting in the silkworm by use of a baculovirus. (5/1272)

Characterization of the 25K FP gene of the baculovirus Bombyx mori nucleopolyhedrovirus: implications for post-mortem host degradation. (6/1272)

Studies on silk fibroin of Bombyx mori. I. Fractionation of fibroin prepared from the posterior silk gland. (7/1272)

A TATA element is required for tRNA promoter activity and confers TATA-binding protein responsiveness in Drosophila Schneider-2 cells. (8/1272)

Experimental immunology Proteomic and immunological identification of two new allergens from silkworm ( Bombyx mori L.) pupae ...

Analysis of correlation between haemolymph and midgut tissue amylase with commercial characters of silkworm Bombyx mori L. -...

Burst expansion, distribution and diversification of MITEs in the silkworm genome | BMC Genomics | Full Text

Microbiology Society Journals | A baculovirus isolated from wild silkworm encompasses the host ranges of Bombyx mori...

Browse by Author - [email protected]

Silkworm larvae and cocoon, Bombyx mori, against white background Stock Photo by Lifeonwhite

Studies on the Mode of Action of the Diapause Hormone in the Silkworm, BOMBYX MORI L., | Journal of Experimental Biology

Larva and Caterpillar of Silkworm (Bombyx Mori) Giclee Print at AllPosters.com

Silkworm larvae, Bombyx mori, against white background Stock Photo by Lifeonwhite

Generation of hybrid transgenic silkworms that express Bombyx mori prolyl-hydroxylase alpha-subunits and human collagens in...

DF090416

DF090445

Effects of KK-42, an imidazole derivative, on rearing and reproductive performance of Bombyx mori L. during the hot, wet season...

Sequences of two cDNAs encoding silkworm homologues of Drosophila melanogaster squid gene<...

Identification of a Novel Strong and Ubiquitous Promoter/Enhancer in the Silkworm Bombyx mori | G3: Genes | Genomes | Genetics

RCSB PDB - 1BOM: THREE-DIMENSIONAL STRUCTURE OF BOMBYXIN-II, AN INSULIN-RELATED BRAIN-SECRETORY PEPTIDE OF THE...

Allergenic characterization of 27-kDa glycoprotein, a novel heat stable allergen, from the pupa of silkworm, Bombyx mori<...

RCSB PDB - 3UST: Structure of BmNPV ORF075 (p33) Methods Report Page

Serratiopeptidase - Wikipedia

Silkworm Eggs (Bombyx mori) | Carolina.com

Rab14 from Bombyx mori (Lepidoptera: Bombycidae) shows ATPase activity

"KAIKObase: An integrated silkworm genome database and data mining tool" by Michihiko Shimomura, Hiroshi Minami et al.

A New Genus, Valvaribifidum (Lepidoptera, Bombycidae), with Description of a New Species from China

A novel antibacterial peptide family isolated from the silkworm, Bombyx mori | Biochemical Journal

Items where Subject is "Genetics" - [email protected]

Indexed Papers | BioTech

Advisory Board

PLOS Genetics: Precocious Metamorphosis in the Juvenile Hormone-Deficient Mutant of the Silkworm, Bombyx mori

Suture Riversilk™ (Silk) | Riverpoint Medical

Cloning and rescue of the genome of Bombyx mori bidensovirus, and characterization of a recombinant virus | Virology Journal |...

diapause hormone Summary Report | CureHunter

CiNii Articles - ABE Hiroaki

Genomic boost to protect Assam's muga silkworm | Business Standard News

silkworms « Ewephoric Fibers

A Second-Generation Integrated Map of the Silkworm Reveals Synteny and Conserved Gene Order Between Lepidopteran Insects |...

Silkworms Sylvia A. Johnson - CTValley Bio

Bombyx mori BMCHIR1protein Summary Report | CureHunter

KEEPER OF THE SNAILS: Silkworm Housing Crisis

Cynthia Robinson Weight and Height, Size | Body measurements

A BEATLES' HARD-DIE'S SITE: Beatles' Wives - 1: Cynthia Powell/Lennon

Cynthia Thompson | Information Management

Cynthia Nixon | Cynthia Nixon had hair worries for wedding | Contactmusic.com

Dr. Samia Malik, MD - Tampa, FL - Neurology | Healthgrades.com

Home - Dr Samia Hasan

Samia Rasasi (samiarasasi) on Pinterest

RAGE AGAINST the MACHINE Chapter 1

Role of Bmbuffy in hydroxycamptothecine-induced apoptosis in BmN-SWU1 cells of the silkworm, Bombyx mori. | Sigma-Aldrich

Start Reading The Silkworm by Robert Galbraith (J.K. Rowling)

Q&A With Dr. Cynthia Clark on New Civility Mentor Simulations

Dr. Cynthia Hom, MD - Palo Alto, CA - Internal Medicine | Healthgrades.com

Bombyx mori

Two-hybrid screening

Dryocampa rubicunda

Avshalom Pollak

Pachypasa otus

Coa vestis

List of organisms by chromosome count

6,7-dihydropteridine reductase

Silk

List of sequenced animal genomes

Stazione Bacologica Sperimentale

Moth

Mir-277 microRNA precursor family

Moth

Slow bee paralysis virus

Lepidoptera

Evolution of insects

List of edible insects by country

Micropyle (zoology)

Corazonin

Bombykol

Bombycidae