Adenovirus A vector system that is used in gene therapy (especially for genes that you want to be active in the lungs).
Agricultural Biotechnology A range of tools, including traditional breeding techniques, that alter living organisms, or parts of organisms, to make or modify products; improve plants or animals; or develop microorganisms for specific agricultural uses. Modern biotechnology today includes the tools of genetic engineering.
Agrobacterium a type of soil-inhabiting bacteria that is capable of introducing DNA from plasmids in the bacteria into the genome of plant cells.
Allele one of several alternate forms (DNA sequences) that resides at the same locus on the chromosome and controls the same phenotype (although with potentially differing effects).
Allergen A substance, usually a protein, that can cause an allergy or allergic reaction in the body.
Allergy A reaction by the body's immune system after exposure to a particular substance, often a protein.
Amino acid a building block of proteins. Each protein consists of a specific sequence of amino acids (with the sequence of amino acids determined by the sequence of the underlying DNA). There are 20 types of amino acid molecules that make up proteins.
Antibiotic a chemical substance that can kill or inhibit the growth of a microorganism.
Antibody a type of protein, produced by certain blood cells in mammals and birds, that specifically recognize a foreign antigen.
Antigen a molecule, usually a protein or polysaccharide (sugar), that induces the production of specific antibodies against itself. Molecules on the surfaces of viruses and bacteria are antigens.
Antisense the complementary strand of a coding sequence (gene); often an expressed copy of an antisense sequence is transformed into a cell or organism to shut off the expression of the corresponding gene.
Bacillus thuringiensis (Bt) A soil bacterium that produces toxins that are deadly to some pests. The ability to produce Bt toxins has been engineered into some crops. See Bt crops.
Beta galactosidase A protein that metabolizes the sugar, lactose, into two smaller sugar molecules. Used with a chromogenic analog of lactose, beta galactosidase can be used as a reporter gene to confirm the presence/expression of a transformation experiment.
Biodegradation the process whereby a compound is decomposed by natural biological activity.
Bioinformatics A broad term to describe applications of computer technology and information science to organize, interpret, and predict biological structure and function. Bioinformatics is ususally applied in the context of analyzing DNA sequence data.
Biomagnification a problem associated with the introduction of xenobiotic compounds into the biosphere in which the concentration of the compound increases as it passes up the food chain.
Biopharming The production of pharmaceuticals such as edible vaccines and antibodies in plants or domestic animals.
Biopolymers Long-chain compounds composed of organic molecule subunits, for example plastics, that are synthesized by living organisms.
Bioremediation the use of biological organisms to render hazardous wastes non-hazardous or less hazardous.
Bt crops Crops that are genetically engineered to carry a gene from the soil bacterium Bacillus thuringiensis (Bt). The bacterium produces proteins that are toxic to some pests but non-toxic to humans and other mammals. Crops containing the Bt gene are able to produce this toxin, thereby providing protection for the plant. Bt corn and Bt cotton are examples of commercially available Bt crops.
cDNA (complementary DNA) a single-stranded DNA molecule which is complementary to a specific RNA molecule and synthesized from it. Complementary DNA's are important laboratory tools as DNA probes and for isolating and studying individual genes.
Cell the fundamental level of structural organization in complex organisms. Cells contain a nucleus (with chromosomes) and cytoplasm with the protein-synthesis machinery, bounded by a membrane.
Central Dogma the underlying model for describing gene structure and function. It states that genes are transcribed in the nucleus into messenger RNA molecules, which are then translated into proteins on ribosomes.
Chromosome a condensed structure found in the cell nucleus that contains the genes of that cell. Chromosomes are composed of DNA wrapped in proteins. They can be seen with a microscope during certain stages of cell division, when they appear as rod-like structures.
Clone A genetic replica of an organism created without sexual reproduction.
Cloning asexually producing multiple copies of genetically identical cells or organisms descended from a common ancestor (compare with gene cloning).
Codon a triplet of nucleotides in a DNA or RNA molecule that codes for one of the 20 amino acids in proteins, or for a signal to start or stop protein production. Each gene that codes for protein is a series of codons that gives the instructions for building that protein.
Complementary the opposite or "mirror" image of a DNA sequence. A complementary DNA sequence has an "A" for every "T" and a "C" for every "G". Two complementary strands of single stranded DNA will join to form a double-stranded molecule.
Cross-pollination Fertilization of a plant with pollen from another plant. Pollen may be transferred by wind, insects, other organisms, or humans.
DNA (deoxyribonucleic acid) the substance of heredity; a long linear molecule composed of deoxyribose (a sugar), phosphate, and one of four bases, adenine (A), thymine (T), guanine (G) and cytosine (C). DNA contains the genetic information necessary for the duplication of cells and for the production of proteins. In its native state, DNA is a double helix composed of two complementary strands.
DNA chip a high density array of short DNA molecules bound to a solid surface for use in probing a biological sample to determine gene expression, marker pattern or nucleotide sequence of DNA/RNA. See also Microarray.
DNA probe a single-stranded DNA molecule used in laboratory experiments to detect the presence of a complementary sequence among a mixture of other singled-stranded DNA molecules (same as Gene Probe).
DNA profie the distinctive pattern of DNA restriction fragments or PCR products that can be used to identify, with great certainty, any person, biological sample from a person, or organism from the environment.
DNA sequencing determining the order of nucleotides in a specific DNA molecule.
Dominant a phenotype that is expressed in organisms that are either homozygous or heterozygous for the corresponding allele.
Electrophoresis a method of separating substances, such as DNA fragments, by using an electric field to make them move through a "gel" at rates that correspond to their electric charge and size.
Embryo transfer implantation of an embryo into the oviduct or uterus.
Enzyme A functional protein that catalyzes (speeds up) a chemical reaction. Enzymes control the rate of metabolic processes in an organism; they are also the active agents in the fermentation process.
Enzyme-linked immunosorbent assay (ELISA) A technique using antibodies for detecting specific proteins. Used to test for the presence of a particular genetically engineered organism.
Expressed Sequence Tag (ESTs) One of many (thousands) of sequence-reads derived from the mRNA isolated from a tissue. ESTs provide a crude "inventory" of the genes that are being expressed in that tissue at that stage of development. ESTs are often used to populate DNA microarrays.
Fermentation The biochemical process of converting a raw material (such as glucose, a sugar) into a final product (such as ethanol)
Field trial A test of a new technique or variety, including biotech-derived varieties, done outside the laboratory but with specific requirements on location, plot size, methodology, etc.
Functional genomics the field of study that attempts to determine the function of all genes (and gene products) largely based on knowing the entire DNA sequence of an organism.
Gene "gun" A device for transforming cells with foreign DNA that works by propelling small metal spheres covered with a DNA molecule into living cells.
Gene (DNA) sequencing Determining the exact sequence of nucleotide bases in a strand of DNA to better understand the behavior of a gene.
Gene cloning isolating a gene and making many copies of it by inserting the DNA sequence into a vector, then into a cell, and allowing the cell to reproduce and make many copies of the gene.
Gene expression The result of the activity of a gene or genes which influence the biochemistry and physiology of an organism and may change its outward appearance.
Gene flow The movement of genes from one individual or population to another genetically compatible individual or population.
Gene library a collection of DNA fragments (carried on vector molecules) which, taken together, represents the total DNA of a certain cell type or organism.
Gene mapping Determining the relative physical locations of genes on a chromosome. Useful for plant and animal breeding.
Gene regulation process of controlling the synthesis or suppression of gene products in specific cells or tissues.
Gene splicing joining pieces of DNA from different sources using recombinant DNA technology.
Gene the fundamental unit of heredity; a bundle of information for a specific biological structure or function.
Gene therapy introducing a normal, functioning copy of a gene into a cell in which that gene is defective.
Genetic code the language in which DNA's instructions are written. The code consists of triplets of nucleotides (codons), with each triplet corresponding to one amino acid in a protein structure or to a signal to start or stop protein production.
Genetic engineering the manipulation of genes, composed of DNA, to create heritable changes in biological organisms and products that are useful to people, living things, or the environment.
Genetic erosion the loss of genetic diversity caused by either natural or man-made processes.
Genetic modification The production of heritable improvements in plants or animals for specific uses, via either genetic engineering or other more traditional methods. Some countries other than the United States use this term to refer specifically to genetic engineering.
Genetic pollution uncontrolled escape of genetic information (frequently refering to products of genetic engineering) into the genomes of organisms in the environment where those genes never existed before.
Genetically engineered organism (GEO) An organism produced through genetic engineering.
Genetically modified organism (GMO) An organism produced through genetic modification.
Genetics The study of the patterns of inheritance of specific traits.
Genome the complete genetic repertoire of an organism.
Genomic library A collection of biomolecules made from DNA fragments of a genome that represent the genetic information of an organism that can be propagated and then systematically screened for particular properties. The DNA may be derived from the genomic DNA of an organism or from DNA copies made from messenger RNA molecules. A computer-based collection of genetic information from these biomolecules can be a "virtual genomic library."
Genomics the field of study that seeks to understand the structure and function of all genes in an organism based on knowing the organism's entire DNA sequence and extensive reliance on powerful computer technologies.
Genotype The specific combination of alleles present at a single locus in the genome.
Germ cells the sex cell(s) of an organism (sperm or egg, pollen or ovum). They differ from other cells (somatic) in that they contain only half the usual number of chromosomes. Germ cells fuse during fertilization to begin the next generation.
Germplasm the sum total of all hereditary material in a single (interbreeding) species.
Green Revolution an agresssive effort between 1950 and 1975 where agricultural scientists applied modern principles of genetics and breeding to improve crops grown primarily in less-developed countries.
Hemoglobin a very well-characterized protein that carries oxygen within the blood of animals.
Herbicide a chemical compound that kills targeted plants (weeds).
Herbicide-tolerant crops Crops that have been developed to survive application(s) of particular herbicides by the incorporation of certain gene(s) either through genetic engineering or traditional breeding methods. The genes allow the herbicides to be applied to the crop to provide effective weed control without damaging the crop itself.
Heterozygous situation where the two alleles at a specific genetic locus are not the same.
Homologous stretches of DNA that are very similar in sequence, so similar that they tend to stick together in hybridization experiments. Homologous can also be used to indicate related genes in separate organisms controling similar phenotypes.
Homozygous situation where the two alleles at a specific genetic locus are identical to one another
Hybrid The offspring of any cross between two organisms of different genotypes.
Hybridization bringing complementary single strands of nucleic acids together so that they stick and form a double strand. Hybridization is used in conjunction with DNA and RNA probes to detect the presence or absence of specific complementary nucleic acid sequences.
Identity preservation The segregation of one crop type from another at every stage from production and processing to distribution. This process is usually performed through audits and site visits and provides independent third-party verification of the segregation.
In vitro fertilization fertilizing an animal egg with sperm in a test tube or culture dish (not in the uterus or oviduct), and then implanting the fertilized egg back into the uterus or oviduct.
In vitro outside the living organism; in a test tube.
In vivo within the living organism
Insecticide resistance The development or selection of heritable traits (genes) in an insect population that allow individuals expressing the trait to survive in the presence of levels of an insecticide (biological or chemical control agent) that would otherwise debilitate or kill this species of insect. The presence of such resistant insects makes the insecticide less useful for managing pest populations.
Insect-resistance management A strategy for delaying the development of pesticide resistance by maintaining a portion of the pest population in a refuge that is free from contact with the insecticide. For Bt crops this allows the insects feeding on the Bt toxin to mate with insects not exposed to the toxin produced in the plants.
Insect-resistant crops Plants with the ability to withstand, deter or repel insects and thereby prevent them from feeding on the plant. The traits (genes) determining resistance may be selected by plant breeders through cross-pollination with other varieties of this crop or through the introduction of novel genes such as Bt genes through genetic engineering.
Intellectual property rights The legal protection for inventions, including new technologies or new organisms (such as new plant varieties). The owner of these rights can control their use and earn the rewards for their use. This encourages further innovation and creativity for the benefit of us all. Intellectual property rights protection includes various types of patents, trademarks, and copyrights.
Locus the position on a chromosome where the gene for a particular trait resides; a locus may be occupied by any one of several alleles (variants) for a given gene.
Marker a detectable genetic variant, such as one of the ABO blood types, antibiotic resistance, or different DNA fragment patterns. Markers located near genes of interest can be used to deduce the presence or absence of deleterious genes; other markers can be used to detect the presence of an organism in the environment.
Messenger RNA (mRNA) the ribonucleic acid molecule that transmits the genetic information from the nucleus to the cytoplasm, where it directs protein synthesis.
Microarray a large set of cloned DNA molecules spotted onto a solid matrix (such as a microscope slide) for use in probing a biological sample to determine gene expression, marker pattern or nucleotide sequence of DNA/RNA. See also DNA Chip.
Microsatellite a repeated motif of nucleotides, usually only two or three bases in length, where the number of repeats frequently differs between different members of a species.
Mineralization the conversion of organic compounds into inorganic (mineral) ones. For example, the conversion of an organic solvent, like ethanol, into carbon dioxide (CO2) and water (H2O).
Molecular biology The study of the structure and function of proteins and nucleic acids in biological systems.
Monoclonal antibodies antibodies derived from a single source or clone of cells, all recognizing only one kind of antigen.
Mutation a permanent change in the genetic material involving either a physical alteration in the chromosome or a biochemical change in the underlying DNA molecule.
Nucleotide A subunit of DNA or RNA consisting of a nitrogenous base (adenine, guanine, thymine, or cytosine in DNA; adenine, guanine, uracil, or cytosine in RNA), a phosphate molecule, and a sugar molecule (deoxyribose in DNA and ribose in RNA). Many of nucleotides are linked to form a DNA or RNA molecule.
Nucleus membrane-bound structure in the cell that contains the chromosomes (genetic material). The nucleus divides whenever the cells divides.
Nutriceuticals common food products that have been modified (potentially by genetic engineering) to have enhanced nutritional characteristics.
Organic agriculture A concept and practice of agricultural production that focuses on production without the use of synthetic inputs and does not allow the use of transgenic organisms. USDA's National Organic Program has established a set of national standards for certified organic production which are available online.
Outcrossing Mating between different populations or individuals of the same species that are not closely related. The term "outcrossing" can be used to describe unintended pollination by an outside source of the same crop during hybrid seed production.
Pathogen a specific biological causative agent of disease in plants or animals.
Pesticide resistance The development or selection of heritable traits (genes) in a pest population that allow individuals expressing the trait to survive in the presence of levels of a pesticide (biological or chemical control agent) that would otherwise debilitate or kill this pest. The presence of such resistant pests makes the pesticide less useful for managing pest populations.
Pest-resistant crops Plants with the ability to withstand, deter or repel pests and thereby prevent them from damaging the plants. Plant pests may include insects, nematodes, fungi, viruses, bacteria, weeds, and other.
Phenotype a biological characteristic or trait possessed by an organism that results from the expression of a specific gene.
Plant breeding The use of cross-pollination, selection, and certain other techniques involving crossing plants to produce varieties with particular desired characteristics (traits) that can be passed on to future plant generations.
Plant pests Organisms that may directly or indirectly cause disease, spoilage, or damage to plants, plant parts or processed plant materials. Common examples include certain insects, mites, nematodes, fungi, molds, viruses, and bacteria.
Plant-incorporated protectants (PIPs) Pesticidal substances introduced into plants by genetic engineering that are produced and used by the plant to protect it from pests. The protein toxins of Bt are often used as PIPs in the formation of Bt crops.
Plasmid a small, self-replicating molecule of DNA that is separate from the main chromosome. Because plasmids are easily moved from cell to cell or to the test tube, scientists often cleave them with restriction enzymes and insert foreign DNA, and then transfer the recombinant DNA plasmid molecule (as a vector) into other cells.
Polyhydroxybutyrate an example of a biopolymer, originally discovered in the bacterium Alcaligenes eutropus. The gene coding for this compound has since been moved to other bacteria and to crop plants in order to produce novel forms of plastics.
Polymer a chemical compound or mixture of compounds formed by polymerization and consisting of repeating structural sub-units.
Polymerase Chain Reaction (PCR) a technique to amplify a specific DNA sequence in vitro using a DNA replicating enzyme, specific oligonucleotide primers, and repeated cycles of heating and cooling. PCR often amplifies the starting material many thousands or millions of times.
Promoter a DNA sequence preceding a gene that contains regulatory sequences controlling the rate of RNA transcription of that gene. In effect, promoters control when and in which cells a given gene will be expressed.
Protein a molecule composed of amino acids arranged in a special order determined by the genetic code. Proteins are required for the structure and function of all living organisms.
Recessive a phenotype that is expressed in organisms only if it is homozygous for the corresponding allele.
Recombinant DNA (rDNA) A molecule of DNA formed by joining different DNA segments using recombinant DNA technology.
Recombinant DNA technology Procedures used to join together DNA segments in a cell-free system (e.g. in a test tube outside living cells or organisms). Under appropriate conditions, a recombinant DNA molecule can be introduced into a cell and copy itself (replicate), either as an independent entity (autonomously) or as an integral part of a cellular chromosome.
Reporter gene a gene sequence that is easily observed when it is expressed in a given tissue or at a certain stage of development.
Restriction enzyme an enzyme that recognizes a specific nucleotide base sequence (usually four to six base pairs in length) in a double stranded DNA molecule and cuts both strands of the DNA molecule at every place where this sequence occurs.
Restriction fragment length polymorphism (RFLP) the presence of two or more variants in the size of DNA fragments produced by a restriction enzyme. These different sized fragments result from an inherited variation in the presence of a restriction enzyme's target sequence. RFLP's are used for gene mapping and DNA profiling.
Retrovirus a type of virus that can insert its DNA into the genome of its host cell. This ability has been used as a basis for genetic transformation of animal cells.
Rhizobium the group of bacteria that form symbiotic associations with legume plants and are responsible for fixing atmospheric nitrogen into a form that can be used by plants and animals.
Ribonucleic Acid (RNA) A chemical substance made up of nucleotides compound of sugars, phosphates, and derivatives of the four bases adenine (A), guanine (G), cytosine (C), and uracil (U). RNAs function in cells as messengers of information from DNA that are translated into protein or as molecules that have certain structural or catalytic functions in the synthesis of proteins. RNA is also the carrier of genetic information for certain viruses. RNAs may be single or double stranded.
Roundup-Ready crops, such as soybeans and cottons, that have been genetically modified to tolerate the chemical herbicide, glyphosate.
Screening a method to identify specific cells (or clones of cells) expressing a specific phenotype (trait), such as the ability to turn "blue-gal" into a bluish color.
Selectable marker A gene, often encoding resistance to an antibiotic or an herbicide, introduced into a group of cells to allow identification of those cells that contain the gene of interest from the cells that do not. Selectable markers are used in genetic engineering to facilitate identification of cells that have incorporated another desirable trait that is not easy to identify in individual cells.
Selection a method to retain specific cells (or clones of cells) expressing a specific trait, such as antibiotic or herbicide resistance, while killing off all other cells that do not express that trait.
Selective breeding Making deliberate crosses or matings of organisms so the offspring will have particular desired characteristics derived from one or both of the parents.
Sequence tandem repeat A highly polymorphic region of DNA that can be used to produce a unique DNA profile for a given individual.
Somatic cell cells in the body that are not involved in sexual reproduction (that is, not germ cells).
Starter culture microorganisms that are purposely added to foods to affect flavor, color, texture, smell, or taste.
Stem Cells Self-newing cells that with proper growth conditions can be made to differentiate into a number of different cell types with specific biological functions.
Tissue culture growing cells, tissues, or tissue fragments (from complex, multicellular organisms) on a nutrient medium in a dish, test tube, or flask.
Totipotent a cell that is capable of regenerating an entire adult organism by itself.
Totipotent Cells Cells from the Inner-cell mass that can give rise to a complete individual.
Traditional breeding Modification of plants and animals through selective breeding. Practices used in traditional plant breeding may include aspects of biotechnology such as tissue culture and mutational breeding.
Transcription the transfer of information from specific sequences in a DNA molecule to produce new strands of messenger RNA, which then carry this information from the nucleus to the cytoplasm (where the messenger RNA is translated into protein).
Transformation introduction of an exogenous DNA molecule into a cell, causing it to acquire a new phenotype (trait).
Transgene A gene from one organism inserted into another organism by recombinant DNA techniques.
Transgenic an organism that has been transformed with a foreign DNA sequence.
Transgenic organism An organism resulting from the insertion of genetic material from another organism using recombinant DNA techniques.
Translation synthesis of protein using information contained in a messenger RNA molecule.
Vaccine a preparation of killed or living attenuated microorganisms or part thereof, that are administered to a person or animal to produce artificial immunity to a particular disease.
Variety A subdivision of a species for taxonomic classification also referred to as a 'cultivar.' A variety is a group of individual plants that is uniform, stable, and distinct genetically from other groups of individuals in the same species.
Vector 1. A type of DNA element, such as a plasmid, or the genome of a bacteriophage, or virus, that is self-replicating and that can be used to transfer DNA segments into target cells. 2. An insect or other organism that provides a means of dispersal for a disease or parasite.
Virus an infectious agent that requires a host cell to replicate. Viruses are usually composed of an RNA or DNA molecule wrapped in a protein coat. Sometimes, viruses are used as vectors.
Xenobiotic literally, "stranger to organism". Compounds not degraded by organisms in the environment.
Xenotransplantation Transplanting a foreign tissue into another species. For example, pig organs have been used in transplantation studies to replace certain diseased human organs.