Glossary

The following terms are commonly used in the molecular biology and virology, and many are referred to on this website.

Antibody (abbrev. Ab) A molecule produced by animals in response to antigen which has the particular property of combining specifically with the antigen which induced its formation. Sometimes it is also referred as immunoglobulins although antibody is a more specific term.
Attenuated virus A weakened virus with reduced ability to infect or produce disease. Some vaccines are based on attenuated viruses. Recombination tends to have the effect of attenuating the recombined virus relative to the Wild Type.
Broiler Chicken grown for meat production.
Challenge Dose of disease causing organism given to simulate disease.
Coccidiosis Coccidiosis is one of the most common and costly diseases in poultry and is prevalent worldwide. The parasitic disease causes weight loss and poor feed conversion and the death rate in chicks and adult birds can be high.
Cytokines/cytokin Soluble polypeptides (hormones) that mediate cellular interactions and regulate cell growth and function. As a result, they regulate the immune response.
DNA Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions specifying the biological development of all cellular forms of life (and many viruses).
Enhancer An enhancer is a nucleotide sequence to which transcription factor(s) bind, and which increases the transcription of a gene. It is NOT part of a promoter; the basic difference being that an enhancer can be moved around anywhere in the general vicinity of the gene (within several thousand nucleotides on either side or even within an intron), and it will still function. It can even be clipped out and spliced back in backwards, and will still operate.
Expression To "express" a gene is to cause it to function. A gene which encodes a protein will, when expressed, be transcribed and translated to produce that protein. A gene which encodes RNA rather than a protein (for example, an rRNA gene) will produce that RNA when expressed.
FAV See Fowl Adenovirus Vector.
Fowl Adenovirus Vector Imugene’s vaccine delivery system for poultry.
Gene A unit of heredity, usually a stretch of genetic material (DNA or RNA) with a defined function in the organism or cell, such as one for a protein. There are many genes within a genome.
Genome The total DNA contained in each cell of an organism.
Infectious Capable of being transmitted between individuals, with or without actual contact. Cf. Virulence, which involves the causation of harm in the subject being infected.
in vitro An artificial environment created outside a living organism, e.g., a test tube or culture plate, used in experimental research to study a disease or process.
in ovo In embryo/egg.
Marker Two typical usages:
Molecular weight size marker: a piece of DNA of known size, or a mixture of pieces with known size, used on electrophoresis gels to determine the size of unknown DNA’s by comparison.
Genetic marker: A known site on the chromosome. It might for example be the site of a locus with some recognizable phenotype, or it may be the site of a polymorphism that can be experimentally discerned.
Nucleotide A monomer or the structural unit of nucleotide chains forming nucleic acids as RNA and DNA.
PAV See Porcine Adenoviral Vector.
Polymerase chain reaction (abbrev. PCR) A technique for replicating a specific piece of DNA in-vitro even in the presence of excess non-specific DNA. Polymerase Chain Reaction (PCR) is the basis for a number of extremely important methods in molecular biology. It can be used to detect and measure vanishingly small amounts of DNA and to create customized pieces of DNA. It has been applied to clinical diagnosis and therapy, to forensics and to vast numbers of research applications. It would be difficult to overstate the importance of PCR to science.
Porcine Adenoviral Vector Imugene’s vaccine delivery system for pigs.
Porcine Circovirus Porcine Circovirus is a major pig disease. This disease stunts growth, increases mortality and weight loss progressing to emaciation in pigs aged 5-18 weeks.
Poultry Chickens (Gallus gallus), true turkeys or (Coturnix species of) quail.
Promoter A piece of genetic material that acts as a gene switch, so that a gene can become expressed in the cell. It is the region at which the RNA polymerase binds to start transcription. Most promoters are located upstream of the gene, except that some eukaryotic genes have promoters internal to the gene.
Reading frame When mRNA is translated by the cell, the nucleotides are read three at a time. By starting at different positions, the groupings of three that are produced can be entirely different. If we shift the grouping again, we will just get the first reading frame again. The reading frame that is actually used is determined by the first methionine codon (the initiation codon). Once that first AUG is recognized, the pattern of triplet groupings follows unambiguously.
Receptor A specific molecule on the surface of a cell which is used by a virus for attachment.
Release The stage of viral replication at which virus particles escape the infected cell.
RNA A nucleic acid consisting of a string of covalently-bound nucleotides. It is biochemically distinguished from DNA by the presence of an additional hydroxyl group, attached to each pentose ring; as well as by the use of uracil, instead of thymine. One of the main functions of RNA is to copy genetic information from DNA (via transcription) and then translate it into proteins (by translation).
Sequence As a noun, the sequence of a DNA is the structure of a DNA molecule, in terms of the sequence of bases it contains. As a verb, "to sequence" is to determine the structure of a piece of DNA; i.e. the sequence of nucleotides it contains.
Serotype A group of related micro-organisms or viruses distinguished by differing antigens. Each serotype represents a specific organism or virus within the species level of classification.
Transcription The process of copying DNA to produce an RNA transcript. This is the first step in the expression of any gene. The resulting RNA, if it codes for a protein, will be spliced, polyadenylated, transported to the cytoplasm and by the process of translation will produce the desired protein molecule.
Translation The process of decoding a strand of mRNA, thereby producing a protein based on the code. This process requires ribosomes (which are composed of rRNA along with various proteins) to perform the synthesis, and tRNA to bring in the amino acids. Sometimes, however, people speak of "translating" the DNA or RNA when they are merely reading the nucleotide sequence and predicting from it the sequence of the encoded protein. This might be more accurately termed "conceptual translation".
Ubiquitous Present everywhere: common and prevalent.
Vector Specifically a viral vector: Modified virus capable of moving or transporting genetic material into the body.
Virulence Ability (of pathogens) to infect organisms and cause disease.
Viruses Obligate intracellular parasites that require the host cell's biochemical machinery to drive protein synthesis and metabolize sugars.