Genetic Engineering: altering the genetic material of cells or organisms to enable them to make new substances or perform new functions. (HGPIA)

The process of using “recombinant DNA technology” to alter the genetic makeup of an organism. Traditionally, humans have manipulated “genomes” indirectly by controlling “breeding” and selecting offspring with desired “traits.” Genetic engineering involves the direct manipulation of one or more “genes.” Most often, a gene from another “species” is added to an organism's genome to give it a desired “phenotype.” (NHGRI) Inserting genes from another organism into its DNA. Once inserted, the foreign gene may use the cell machinery of its “host” to "synthesize" the “protein” that it originally “coded” for in the organism it was derived from. (OxfordMed) A rapidly expanding branch of biology. Now used to make a considerable range of useful substances. (Indge, 119) Also referred to as ‘genome engineering.’


Clone: an identical copy of a “DNA sequence” or entire gene; one or more cells derived from and identical to a single ancestor cell. (NCI3) Group of genetically identical individuals or cells derived from a single cell by repeated asexual divisions. (Lawrence) Also referred to as ‘cell line.’

Cloning: process of making identical copies of an organism, cell, or DNA sequence. Cloning also can refer to asexual reproduction. (NHGRI) The isolation of a single cell and the growth of a clone of identical cells from it. (Lawrence) The formation of one or more genetically identical organisms derived by vegetative reproduction from a single cell. The source nuclear material can be embryo-derived, fetus-derived, or taken from an adult “somatic cell.” (MeSH) To isolate a gene or specific sequence of DNA. (NCI3)

Animal Cloning: produces complete, genetically identical animals such as the famous Scottish sheep, Dolly. (HGPIA) Scottish scientists (in 1997) removed the nucleus from an unfertilized egg and fused this egg with the nucleus of an adult cell taken from a sheep’s udder. The fused egg was grown in “culture” and then transplanted into a surrogate mother. This was the first report of animal cloning using DNA from an adult animal. More recently, animal cloning has been achieved in mice, cattle, and cats. (Micklos, 108) Also referred to as ‘nuclear transfer.’

Gene Cloning: a type of cloning (that) exploits the natural process of “cell division” to make many copies of an entire cell. (HGPIA) A process by which scientists “amplify” a desired DNA sequence. The target sequence is isolated, inserted into another DNA molecule (known as a “vector”), and introduced into a suitable host cell. Then, each time the host cell divides, it replicates the foreign DNA sequence along with its own DNA. (NHGRI) Takes advantage of the natural ability of cells to duplicate DNA by “replication.” The gene is inserted into a vector. The vector, with its gene insert, is introduced into the appropriate host cell, where it is duplicated by the host cell’s replication machinery. Subsequent “mitosis” of the host creates a “population” of clones. From this population, the gene insert can be harvested in quantities needed for research. (Micklos, 108) Uses specialized DNA technology to produce multiple, exact copies of a single gene or other segment of DNA to obtain enough material for further study. This process (was) used by researchers in the "Human Genome Project.” The resulting copied collections of DNA molecules are called “clone libraries.” (HGPIA) The simple principle of cutting and pasting “DNA fragments” is the backbone of gene cloning technology. (Micklos, 119) Also referred to as ‘molecular cloning’ and  ‘cloning DNA.’

Genetically Engineered Foods: foods that have had genes from other plants or animals inserted into their genetic codes. Potential benefits of genetically engineered food include more nutritious food, disease-resistant and/or drought-resistant plants, and medicinal foods that could be used as “vaccines” or other medications. Potential risks include modified plants or animals (that) have genetic changes that are unexpected and harmful, and modified organisms (that) interbreed with natural organisms and out-compete them. (This might) lead to extinction of the original organism or to other unpredictable environmental effects. (Also) plants may be less resistant to some pests and more susceptible to others. (PubMedHealth2)

Recombinant: in genetics, describes DNA, proteins, cells, or organisms that are made by combining genetic material from two different sources. Recombinant substances are made in the laboratory and are being studied in the treatment of cancer and for many other uses. (NCI1) (Offspring) that exhibit mixing of maternal and paternal “alleles” on a single “chromosome.” (Lewis, 101)

Recombinant DNA: DNA artificially constructed by combining genes from different organisms or by cloning chemically altered DNA, usually for the purpose of genetic manipulation. (NCIt) Combining two pieces of DNA creates a new piece containing both. (Micklos, 119) Biologically active DNA which has been formed by the "in vitro" joining of segments of DNA from different sources. (MeSH)

Recombinant DNA Technology: a technology that uses "enzymes" to cut and paste together DNA sequences of interest. The recombined DNA sequences can be placed into vehicles that ferry the DNA into a suitable host cell where it can be copied or expressed. (NHGRI) Adds genes from one type of organism to the genome of another. DNA sequences cut from two sources with the same “restriction enzyme” make sticky ends on each sequence. This enables them to bond together during recombination. When bacteria bearing recombinant DNA divide, they yield many copies of the foreign DNA. Recombinant DNA-based products include “insulin,” "growth hormone," and "clotting" factors. (Lewis, 375- 376) Procedure used to join together DNA segments in an environment outside a cell or organism. Under appropriate conditions, a recombinant DNA molecule can enter a cell and replicate there, either (independently) or after it has become integrated into a cellular chromosome. (HGPIA)

Vector: any vehicle, often a "virus" or a "plasmid" that is used to ferry a desired DNA sequence into a “host cell” as part of a molecular cloning procedure. (NHGRI) Any DNA molecule capable of (independent) replication within a host cell and into which other DNA sequences can be inserted and thus amplified. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain genetic markers to facilitate their... recognition. (NCIt) An agent used to insert a foreign gene or "DNA fragment" into a bacterial or other cell in "genetic engineering" and “gene therapy.” (OxfordMed) Vectors introduce foreign DNA into host cells, where the DNA can be reproduced in large quantities. Vectors are often recombinant molecules containing DNA sequences from several sources. (HGPIA) Also referred to as a ‘cloning vector’ and ‘genetic vector.’

Viral Vector: a "viral" gene used to transfer genes or genetic materials, such as retroviruses and ‘adenoviruses.’ (NCIt) Viruses, especially retroviruses, are often used as vectors; once inside the host cell, the virus can replicate and thus produce copies of the gene. (OxfordMed) Some carry a short DNA sequence, others a long sequence. Even if a viral vector goes where it is intended, it must enter enough cells to alleviate symptoms. It must not integrate into a gene that harms a patient, such as “oncogene” or a “tumor suppressor gene.” (Lewis, 397)