A gene with a level of expression that varies cyclically, and which might therefore be involved in the generation of biological rhythyms. Examples: period, timeless.
One of the two main hypotheses advanced to explain the absence of autoimmune responses: now generally accepted. Clonal deletion is the programmed death of inappropriately ...
The process whereby one or more clones, ie. cells expressing a particular gene sequence are selected by naturally-occurring processes from a mixed population. Generally the ...
A propagating population of organisms, either single cell or multicellular, derived from a single progenitor cell. Such organisms should be genetically identical, though ...
Centrally-acting anti-hypertensive agent that works by inhibiting activity of the sympathoexcitatory neurons that regulate arterial pressure. Considered to be a mixed agonist ...
The process whereby clones are established. The term covers various manipulations for isolating and establishing clones: in simple systems single cells may be isolated without ...
A plasmid vector that can be used to transfer DNA from one cell type to another. Cloning vectors are usually designed to have convenient restriction sites that can be cut to ...
Chinese liver fluke. Can infect man if inadequately cooked fish is eaten and can cause biliary obstruction as a result of liver infestation.
Genus of Gram positive anaerobic spore-forming bacilli commonly found in soil. Many species produce exotoxins of great potency, the best known being C. botulinum, and C. ...
Clostridium difficile toxins
C. difficile enterotoxin A (308 kD) is secreted, enters eukaryotic cell by receptor-mediated endocytosis and once in cytoplasm glucosylates small G-proteins of rho family ...
Vertebrate glycoprotein of uncertain function. Secreted as a 400 amino acid peptide, then cleaved to form two 200 amino acid peptides that are linked by a disulphide bridge. ...
Of acetylcholine receptors: aggregation of the receptors in developing myotubes in the vicinity of the presynaptic terminal, induced by nerve contact. See agrin.
Chick homologue of myoD.
(1) Cell-mediated lympholysis: the process of target cell lysis by CMCs.
(2) Chronic myeloid leukaemia.
See cytotoxic necrotising factors.
Diverse Phylum of diploblastic animals that includes Classes Hydrozoa (freshwater polyps, small jellyfish), Scyphozoa (large jellyfish), and Anthozoa (sea ...
Ectodermal cell of Cnidaria (coelenterates) specialized for defence or capturing prey. Each cell has a nematocyst that can be replaced once discharged.
Process whereby a protein is moved across a membrane as it is being synthesized. This process occurs during the translation of the message at membrane-associated ribosomes in ...
In membrane transport describes tight coupling of the transport of one species (generally Na+) to another (eg. a sugar or amino acid). The transport of Na+ from high to low ...
Colloidal aggregation containing a mixture of organic compounds. One theory of the evolution of life is that the formation of coacervates in the primaeval soup was a step ...
First stage in the formation of a coated vesicle.
Vesicle formed as an invagination of the plasma membrane (a coated pit), and that is surrounded by a basket of clathrin. Associated with receptor-mediated pinocytosis and ...
Polypeptide toxin (71 residues) from Naja kaouthia. One of the alpha-neurotoxins (curaremimetics), it binds to nicotinic acetylcholine receptors with high ...
Drug of abuse and psychostimulant that acts to increase extra-neuronal dopamine in midbrain by binding to the dopamine uptake transporter and hence inhibiting dopamine ...
Bacteria with a spherical shape.
cochlear hair cell
The sound-sensing cell of the inner ear. The cells have modified ciliary structures (hairs), that enable them to produce an electrical (neural) response to mechanical motion ...
Genes in which both alleles of a pair are fully expressed in the heterozygote as, for example, AB blood group in which both A and B antigens are present.
The coding unit of DNA that specifies the function of the corresponding messenger RNA. A triplet of bases recognized by anticodons on transfer RNA and hence specifying an amino ...
Animal of the Phylum Cnidaria. Mostly marine, diploblastic and with radial symmetry. Sea anemones and Hydra are well known examples.
(= celiac disease (USA) )
Gluten enteropathy: atrophy of villi in small intestine leads to impaired absorption of nutrients. Caused by sensitivity to gluten (protein of wheat ...
Body cavity characteristic of most multicellullular animals (all coelomates). Arises within the embryonic mesoderm, that is thereby subdivided into somatic mesoderm and ...
(= coenobia (plural) )
Colony of cells formed by certain green algae, in which little or no specialization of the cells occurs. The cells are often embedded in a mucilaginous ...
Organism that is not subdivided into cells but has many nuclei within a mass of cytoplasm (a syncytium), as for example some fungi and algae, and the acellular slime mould ...
Either: low-molecular weight intermediate that transfers groups between reactions (eg. NAD), or: catalytically active low-molecular weight component of an enzyme (eg. haem). ...
A derivative of adenosine triphosphate and pantothenic acid that can carry acyl groups (usually acetyl) as thioesters. Involved in many metabolic pathways, eg. citric acid ...
(= 2-mercaptoethanesulphonic acid.)
This substance is involved in the formation of methane from carbon dioxide by methanogenic bacteria.
(= CoQ; ubiquinone)
Hydrogen acceptor and donor in the electron transport chain. (Preferred synonym: ubiquinone.)
Inorganic complement of an enzyme reaction, usually a metal ions. See coenzyme.
Actin-severing protein (19 kD), related to destrin. Binds to the side of filaments and is pH sensitive. Shares with tropomyosin a 13 amino acid F-actin binding domain. Very ...
Protein secondary structure motif that does not qualify as alpha-helix, beta sheet or beta turn.
An ubiquitous nuclear organelle containing the mRNA splicing machinery (U1, U2, U4, U5, U6 and U7 snRNAs), the U3 and U8 snRNPs that are involved in pre-rRNA processing, ...
Protein, M(r) 80 kD, (62.6 kD calculated from 576-residue sequence) found in coiled bodies. A relatively short portion of the N-terminus seems to target the ...
A plasmid of E. coli that codes for colicin V, that confers resistance to complement-mediated killing, for a siderophore to scavenge iron, and for F-like pili that permit ...
Methylated derivative of colchicine.
Alkaloid (400 D) isolated from the Autumn crocus ( Colchicum autumnale ) that blocks microtubule assembly by binding to the tubulin heterodimer (but not to tubulin). As a ...
Genus of crocuses. C. autumnale, the Autumn Crocus, is the source of colchicine.
Antibodies that agglutinate particles with greater activity below 32°C. They are IgM antibodies specifically reactive with blood groups I and i in humans, and agglutinate red ...
Inducible antibacterial peptide found in the haemolymph of a tenebrionid beetle following the injection of heat-killed bacteria. Peptide A (glycine-rich, 74 residues) is active ...
Closed hollow cylinder or sheath of leaf-like tissue surrounding and protecting the plumule (shoot axis and young leaves) in grass seedlings.
Closed hollow cylinder or sheath of leaf-like tissue surrounding and protecting the radicle (young root) in grass seedlings.
Bacterial exotoxins (bacteriocins) that affect other bacteria. Colicins E2 and E3 are AB toxins with DNAase and RNAase activity respectively. Most other colicins are ...
Gram negative rod-shaped bacillus. (1) May be used loosely of any rod-shaped bacterium.
(2) Any Gram negative enteric bacillus.
(3) More specifically, bacteria of the genera ...
Major structural protein (285 kD) of extracellular matrix. An unusual protein both in amino acid composition (very rich in glycine (30%), proline, hydroxyproline, lysine, ...
Proteolytic enzyme capable of breaking native collagen. Once the initial cleavage is made, less specific proteases will complete the degradation. Collagenases from mammalian ...
Glycoprotein (100 kD) from chick brain that may act as a repulsive cue in development and inhibit regeneration of mature neurons. Causes the collapse of the nerve growth cone ...
Family of collagenous lectins believed to play an important part in first-line defence by binding to viruses and by opsonizing yeasts and bacteria. Contain a collagen-like region ...
Plant tissue in which the primary cell walls are thickened, especially at the cell corners. Acts as a supporting tissue in growing shoots, leaves and petioles. Often arranged in ...
Stellate cells with long thin processes that ramify through the inhalent canal system of sponges.
Properties that depend upon the numbers of molecules present in solution rather than their chemical characteristics.
Lens that produces a non-divergent beam of light or other electromagnetic radiation. Simpler collimators involve slits. Essential in obtaining good illumination in microscopy and ...
The pili on enteropathogenic forms of E. coli facilitate adhesion of the bacteria to receptors (probably GM1 gangliosides) on gut epithelial cells and are often referred to as ...
Irradiated mice can have their immune systems reconstituted by the injection of bone marrow cells from a non-irradiated animal. The injected cells form colonies in the ...
The first milk secreted by an animal coming into lactation. May be especially rich in maternal lymphocytes and Ig and thus transfer immunity passively.
Large flat organelles formed by the fusion of many cilia. Vertical rows of comb-plates form the motile appendages of Ctenophores.
Method by which large numbers of compounds can be made, usually utilizing solid-phase synthesis. In the simplest form carrier beads would be treated separately so as to couple ...
(= severe combined immunodeficiency syndrome)
Congenital immunodeficiency with thymic agenesis, lymphocyte depletion and hypogammaglobulinaemia: both cellular and humoral ...
Any region of a molecule that binds or reacts with a given compound. Especially of the region of immunoglobulin that combines with the determinant of an appropriate antigen.
Process that occurs during the morula stage of embryogenesis in which blastomeres increase their cell-cell contact area and develop gap junctions. In mice compaction occurs ...
Relatively small plant cell, with little or no vacuole, found adjacent to a phloem sieve tube and originating with the latter from a common mother cell. Thought to be involved ...
In the insect wing, for example, there are two compartments, anterior and posterior, each containing several clones, but clones do not cross the boundary. It seems from studies ...
(1) Bacterial cells with enhanced ability to take up exogenous DNA and thus to be transformed. Competence can arise naturally in some bacteria ( Pneumococcus, Bacillus and ...
Inhibitor that occupies the active site of an enzyme or the binding site of a receptor and prevents the normal substrate or ligand from binding. At sufficiently high ...
A heat-labile system of enzymes in plasma associated with response to injury. Activation of the complement cascade occurs through two convergent pathways. In the classical ...
Binding of complement as a result of its interaction with immune complexes (the classical pathway) or particular surfaces (alternative pathway).
complementary base pairs
The crucial property of DNA is that the two strands are complementary: Guanine and cytosine are complementary and pair up through their hydrogen bonds, as are adenine and ...
The ability of a mutant chromosome to restore normal function to a cell that has a mutation in the homologous chromosome when a hybrid or heterokaryon is formed - the ...
Nerve-terminal syntaxin-binding proteins.
See concanavalin A.
Con A receptors
A common misuse of the term receptor. Con A binds to the mannose residues of many different glycoproteins and glycolipids and the binding is therefore not to a specific site. ...
Non-haem iron-binding protein found in chicken plasma and egg white.
Class of small peptides (17-21 residues) from Conus spp. that inhibit NMDA class of glutamate receptors.
(= Con A)
A lectin isolated from the jack bean, Canavalia ensiformis.
Two or more identical linear molecular units covalently linked in tandem. Especially used of nucleic acid molecules and of units in artificial polymers.
Vacuole formed from the cis face of the Golgi apparatus by the fusion of smaller vacuoles. Within the condensing vacuole the contents are concentrated and may become ...
A mutation that is only expressed under certain environmental conditions, for example temperature-sensitive mutants.
Cell culture medium that has already been partially used by cells. Although depleted of some components, it is enriched with cell-derived material, probably including small ...
A cell culture in which all the cells are in contact and thus the entire surface of the culture vessel is covered. It is also often used with the implication that the cells ...
A system of (usually) epifluorescence light microscopy in which a fine laser beam of light is scanned over the object through the objective lens. The technique is particularly ...
Alteration in the shape -usually the tertiary structure of a protein - as a result of alteration in the environment (pH, temperature, ionic strength) or the binding of a ligand ...
Asexual spore of fungus, borne at the tip of a specialized hypha (conidiophore).
Union between two gametes or between two cells leading to the transfer of genetic material. In eukaryotes the classic examples are in Paramecium and Spirogyra. Conjugation ...
Uncontrolled secretion of aldosterone usually by an adrenal adenoma.
Cell surface protein (70 kD) from mouse fibrosarcoma cells that binds laminin and actin.
Rather general term for mesodermally derived tissue that may be more or less specialized. Cartilage and bone are specialized connective tissue, as is blood, but the term is ...
connective tissue diseases
A group of diseases including rheumatoid arthritis, systemic lupus erythematosus, rheumatic fever, scleroderma and others, that are sometimes referred to as rheumatic ...