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Home >> Dictionary of Bioinformatics, Biochemistry, Biotechnology >> Comparative Gene Mapping - Complementary Homopolymeric Tailing
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Common intermediate
A chemical compound that is common to two chemical reactions, as a reactant in one and a product of the other.
Communicating junctions
Cell junctions that permit electrical or chemical signals to be transmitted from one cell to the next. The gap junctions are the most important communicating junctions in animals.
Communication protocol
An agreed set rules for structuring communication between programmes such as data exchange between nodes on the internet.
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Comparative genomic hybridisation (CGH)
A cytogenetic technique that allows detection of DNA sequences copy number changes throughout the genome in a single hybridisation based on cohybridisation of differentially labelled tumour and normal DNA to human metaphase chromosomes.
Comparative genomics
The comparison of gene numbers functions and locations in diverse organisms in order to identify groups of genes that a unique biological role in a particular organisms.
Comparative modelling
The prediction of protein structure based on related sequences of known structure.
Comparative oncology
The study of naturally developing cancers in animals as models for human disease. Naturally occuring cancers in pet animals, primarily cats and dogs share many features with human cancers including tumour histology, genetics, response to conventional therapy and biological behaviour.
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Comparative positional candidate gene
A gene that is likely to be found in the same region as a DNA marker shown to be linked to a single-locus trait or to a quantitative trait locus (QTL). The likely location of the gene in the genome in a particular species is based on its known location in the map of another species, i.e., is based on the comparative map between the two species.
Compatibility group
Plasmids assigned to a group based on their ability to coexist in the same cell with another plasmids from a different group.
Competence
The ability of bacterial cells to take up exogenous DNA molecules and become genetically transformed.
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Competition hybridisation
A technique to determine the degree of similarity between two nucleic acids based on th degree to which these two molecules hybridise in the presence of a third nucleic acid that functions as a standard.
Competitive inhibitor
An inhibitor has structural for binding to the active site of the enzyme. A competitive inhibitor has structural similarity to the normal substrate. Binding of the inhibitor increases km but does not alter Vmax. Inhibition of succinate dehydrogenase by malonate is a classic example of competitive inhibition. Competitive inhibition can be reserved by increasing substrate concentration.
Competitive PCR
A PCR method based on co-amplification of the target DNA with a homologous or heterologous DNA standard (competitor) which completes with the sample template DNA for the same set of PCR primers. An internal control, similar in sequence to the target nucleic acid, competes with it for primers in the same reaction tube.
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Competitor Rt-PCR
A technique that enables quantification of PCR product by spiking samples with known amounts of a competitor sequence.
Compile
Conversion of higher level programming language into machine code.
Complement
A group of serum proteins that upon activation by antigen-antibody complexes aid in the killing of pathogenic bacteria and/or facilitate phagocytosis.
Complement-fixation test
A serological test for antibodies that is based on the ability of complement to lyse red blood cells.
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The serum to be tested is mixed with antigen and complement and an indicator system containing sheep red blood cells (RBCs) and an antibody against the sheep RBCs. If the serum contains a specific antibody for the antigen, it will combine with it and bind the complement.
As a result, no complement will be available for lysing the sheep RBCs. Thus absence of lysis of sheep RBCs indicates the presence of an antibody in the serum.
Competent
1. Describing bacterial cells that can take up foreign DNA. 2. In mammals a component cell is one that is capable of developing into a fully functional embryo. The opposite is non-component.
Comparative gene mapping
The comparision of map locations of genes between species. Such maps reveal conservations of blocks of genes or large segments of chromosomes between species. In mammals, if a gene has been mapped in humans and mice, then the likely location of that gene in other mammals can be predicated.
Conversely, if a mapped anonymous DNA marker has an effect on a quantitative trait in, for example, monkeys, then knowledge of he comparative map between monkeys and human can identify genes in the homologous region of the human genome that could correspond to the quantitative trait locus. Such genes are called comparative positional candidate genes.
Complement proteins
Proteins that bind to antibody-antigen complexes and help in the degradation of the complexes by proteolysis. These proteins are triggered by the classical and alternative pathways, and cause target cell lysis, phagocytosis, opsonisation and Chemotaxis.
Complement receptor
A receptor found on the surface of erythrocytes, lymphocytes, neutrophils, monocytes and macrophages that binds C3 fragments.
Complement system
A system of serum proteins that is activated by antigen-antibody complexes or by microorganisms. It helps in the elimination of pathogenic microorganisms by causing lysis or promoting their phagocytosis.
Complementarity
The relationship between the two strands of a DNA duplex. Thymine in one strand base pairs with adenine in the other strand whereas cytosine pairs with guanine.
Complementarity-determining regions
See CDR
Complementary base pairing
The formation of hydrogen bonds between adenine and thymine and between guanine and cytosine.
Complementary base sequence
A base sequence that can from hydrogen bonds with another sequence.
Complementary DNA
See cDNA
Complementary entity
1. One of a pair of nitrogenous bases that forms hydrogen bonds with each other. Adenine (A) pairs with thymine (T) [or with Uracil (U) in RNA], and guanine (G) pairs with cytosine (C). 2. One of a pair of segments or strands of nucleic acid that will hybridise with each other.
Complementary homopolymeric tailing
Addition of complementary nucleotide extensions to two different DNA molecules that are subsequently joined together such as a vector with an insert. One of the DNA molecules is given a dA (deoxyadenosine) tail while the other given a dT (deoxythymidine) tail at the 3’-OH end. The two molecules anneal by base pairing at the complementary extensions. Instead of dA-dT tailing, dG (deoxyguanosine) tailing can also be done.
Complementary nucleotides
Members of the pairs adenine-thymine, adenine-uracil, and guanine-cytosine that are capable of base pairing by formation of hydrogen bonds. See nucleotide.
Complementary RNA (cRNA)
Synthetic RNA produced by transcription from a specific DNA single stranded template.
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