Glosary of Cloning Terms

Clone calf (or cow, heifer, bull, etc.) - The resulting individual animal born as a result of cloning technology.

Cloning - The use of a single somatic (non-reproductive) cell from an individual to produce another genetically identical individual.

Chromosomal DNA - The DNA found in the cell nucleus which forms the basic blueprint for an animal's development and individual characteristics.

Cryopreservation - Preservation by subjection to extremely low temperatures. Through cryopreservation, cells (and the DNA they contain) can be stored in liquid nitrogen indefinitely until they're thawed and used for developing cloned embryos.

Culture - The process or technique of making cells or embryos grow in a specific medium outside the organism.

DNA - Deoxyribonucleic acid carries the genetic information in the cell and is capable of self-replication. DNA consists of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds. The sequence of nucleotides determines individual hereditary characteristics.

Electro-fusion - After the somatic cell from the donor animal is inserted in an enucleated egg cell from another animal, a pulse of electricity is used to fuse them.

Embryo Transfer - After an embryo is produced in vitro, either by nuclear transfer or IVF, it is inserted in the uterus of a recipient female animal via an embryo transfer procedure.

Enucleation - Removal of the nucleus (including nuclear DNA) from an oocyte or unfertile egg.

Gene - A gene is the basic unit of heredity. It's a short piece of DNA--specifically, a sequence of nucleotides--that tells the body how to build a particular protein. Proteins are required for the structure, function, and regulation of the body's cells, tissues, and organs. Each protein has unique functions; examples are hormones, enzymes, and antibodies. The combination of all genes makes up the blueprint for an animal's body and its functions.

Genetic Donor - The animal whose DNA is used in the cloning process to produce another animal with the same genetic composition.

Genetic Preservation - The cryopreservation of cells (and the DNA they contain) for possible later use in cloning; these cells are typically obtained from a small tissue sample provided by the client or the client's veterinarian.

Genetics - The branch of biology that deals with the heredity and variation of organisms, which are ultimately determined by the DNA sequence (or genes) the organisms carry. In traditional cattle breeding, a male and female are chosen for breeding based on the likelihood that when the male's sperm cell fertilizes the female's oocyte (egg cell), the random combination of genes from each animal will result in a new animal with desirable genetics. In cloning, the genetics of a single animal are copied rather than being shuffled with the genes of another.

Genetic Copy - An individual calf, born later in time than the original genetic donor. The genetic copy has the same genetic material (nuclear DNA), or genotype, as the original.

Mitochondrial DNA - Mitochondria is an organelle in the cytoplasm of nearly all eukaryotic cells, containing enzymes important for all cell metabolism, including those responsible for converting food to usable energy. Chromosomal DNA, on the other hand, which is found in the cell nucleus, forms the basic “blueprint” for the animal's development and characteristics.

Nuclear Transfer - The process by which a genetic donor's somatic (non-reproductive) cell is fused into an enucleated oocyte (egg). Fusion between the oocyte and the donor cell results in a one-cell embryo that contains a complete set of chromosomal DNA derived entirely from the genetic donor.

Recipient - The surrogate mother animal into which an embryo (produced through cloning technology, or conventional IVF) is transferred for gestation.

Somatic Cell - Any cell in the body other than an oocyte (egg) or sperm cell.

Tissue Sample - A biopsy from the genetic donor for use in genetic preservation. Tissue samples are most often taken from the ear of the genetic donor through a simple ear punch. Samples can also be obtained from a tail head punch, which may be a more desirable procedure for aggressive animals, such as bucking stock.

Transgenic - Transgenic animals are produced by adding exogenous genes, or removing and modifying endogenous genes, so that the expression of the genes are altered, resulting in desirable genotypes and phenotypes. Cloning is not a transgenic process and does not create any genetically modified animals.