Glossary of Biotechnology
Terms
Agrobacterium tumefaciens:
A gram-negative, rod-shaped flagellated bacterium
responsible for crown gall tumor in plants.
Following infection, the TI plasmid from
the bacterium becomes integrated into the
host plant's DNA, and the presence of the
bacterium is no longer necessary for the
continued growth of the cell. This bacterium
is now used to deliberately transfer genetic
material into plants through biotechnology.
Biobased products: Fuels,
chemicals, building materials, or electric
power or heat produced from biological material(s).
The term may include any energy, commercial
or industrial products, other than food or
feed, that uses biological products or renewable
domestic agricultural (plant, animal and
marine), or forestry materials.
Biological boundaries:
A concept that differentiates one organism
from another and suggests that organisms
cannot or should not exchange genetic material.
An alternative concept is that genes are
defined not by the organism from which they
came, but by their function. As scientists
have identified genes in seemingly non-related
organisms such as plants and humans, they
have found identical genes in each.
Biopharming: The production
of biopharmaceuticals in plants or domestic
animals.
Biotechnology: A set of
biological techniques developed through basic
research and now applied to research and
product development. Biotechnology refers
to the use of recombinant DNA, cell fusion,
and new bioprocessing techniques.
Biotechnology-derived:
The use of molecular biology and/or recombinant
DNA technology, or in vitro gene transfer,
to develop products or to impart specific
capabilities in plants or other living organisms.
Bovine spongiform encephalopathy
(BSE): A disease of cattle, related
to scrapie of sheep, also known as “mad
cow disease.” It is hypothesized
to be caused by a prion, or small protein,
which alters the structure of a normal
brain protein, resulting in destruction
of brain neural tissue.
Bt corn: A corn plant that
has been developed though biotechnology so
that the plant tissues express a protein
derived from a bacterium, Bacillus thuringiensis,
which is toxic to some insects but non-toxic
to humans and other mammals.
Cell: The lowest denomination
of life thought to be possible. Most organisms
consist of more than one cell which becomes
specialized into particular functions to
enable the whole organism to function properly.
Cells contain DNA and many other elements
to enable the cell to function.
Chromosomes: The self-replicating
genetic structure of cells containing the
cellular DNA. Humans have 23 pairs of chromosomes.
Control elements: DNA sequences
in genes that interact with regulatory proteins
(such as transcription factors) to determine
the rate and timing of expression of the
genes as well as the beginning and end of
the transcript.
Creutzfeldt-Jakob Disease (CJD):
A disease of humans hypothesized to be caused
by a prion, or a small protein, which alters
the structure of a normal brain protein,
resulting in destruction of brain neural
tissue. The most common form is thought to
have genetic origins. There is strong epidemiologic
and laboratory evidence for a causal association
between new variant CJD and BSE.
Cry1A: A protein derived
from the bacterium Bacillus thuringiensis
that is toxic to some insects when ingested.
This bacterium occurs widely in nature and
has been used for decades as an insecticide
although it constitutes less than 2 percent
of the overall insecticides used.
Cultivar: Synonymous with
variety; the international equivalent of
variety.
Double helix: The twisted-ladder
shape that two linear strands of DNA assume
when complementary nucleotides on opposing
strands bond together.
DNA (deoxyribonucleic acid):
The genetic material of all cells and many
viruses. The molecule that encodes genetic
information. DNA is a double-stranded molecule
held together by weak bonds between base
pairs of nucleotides. The four nucleotides
in DNA contain the bases adenine (A), guanine
(G), cytosine (C), and thymine (T). In nature,
base pairs form only between A and T and
between G and C; thus the base sequence of
each single strand can be deduced from that
of its partner.
Embryonic stem (ES) cells:
Cell lines derived from early embryos that
have the potential to differentiate into
all types of somatic cells as well as to
form germ line cells, and hence whole animals,
when injected into early embryos.
Endogenous retrovirus:
Integrated retrovirus DNA (provirus) derived
from infection of the germline of an ancestral
animal. All animals are thought to carry
numerous endogenous (but nonfunctional) retroviruses,
some of which were inserted many millions
of years ago.
Enucleated oocyte (cytoplast):
An egg cell from which the nucleus has been
removed mechanically.
Eukaryote: Organism whose
cells have (1) chromosomes with nucleosomal
structure and are separated from the cytoplasm
by a two-membrane nuclear envelope, and (2)
compartmentalization of functions in distinct
cytoplasmic organelles. Contrast prokaryotes
(bacteria and cyanobacteria).
Feral: Refers to an individual
or population that has returned to the wild
after a history of domestication.
Fibroblast: A type of relatively
undifferentiated cell found in many parts
of the body involved primarily in wound healing.
Fibroblasts are relatively easy to grow in
cell culture and often are used for this
purpose.
Fitness: The ability to
survive to reproductive age and produce viable
offspring. Fitness also describes the frequency
distribution of reproductive success for
a population of sexually mature adults.
Gene: The fundamental physical
and functional unit of heredity. A gene is
an ordered sequence of nucleotides located
in a particular position on a particular
chromosome that encodes a specific functional
product (such as a protein or RNA molecule).
Gene flow: The exchange
of genetic traits between populations by
movement of individuals, gametes, or spores.
It involves the spread of new variants among
different populations through dispersal.
Gene gun: A device invented
at Cornell University that allows genetic
material to be introduced into a new organism.
The genetic material from the donor is "shot" into
cells of the recipient, and the material
is incorporated into its DNA.
Gene splicing: The isolation
of a gene from one organism and then the
introduction of that gene into another organism
using techniques of biotechnology.
Genetic engineering: The
technique of removing, modifying, or adding
genes to a DNA molecule to change the information
it contains. By changing this information,
genetic engineering changes the type or amount
of proteins an organism is capable of producing,
thus enabling it to make new substances or
perform new functions.
Genetically modified organism (GMO):
Often, the label GMO and the term "transgenic" are
used to refer to organisms that have acquired
novel genes from other organisms by laboratory "gene
transfer" methods.
Genetics: The study of
the patterns of inheritance of specific traits.
Genome: All the genetic
material in the chromosomes of a particular
organism; its size is generally given as
its total number of base pairs.
Genomics: is the mapping
and sequencing of all the genetic material
in the DNA of a particular
organism as well as the use of information
derived from genome sequence data to further
elucidate what genes do, how they are controlled,
and how they work together. See the Microbe
Project for more information.
Genotype: The genetic identity
of an individual. Genotype often is evident
by outward characteristics.
Germline cells: Cells that
contain inherited material that comes from
the eggs and sperm, and that are passed on
to offspring.
Herbicide-tolerant crop:
Crop plants that have been developed to survive
application(s) of one or more commercially
available herbicides by the incorporation
of certain gene(s) via biotechnology methods
such as genetic engineering or traditional
breeding methods (such as natural, chemical,
or radiation mutation).
Homolog: In diploid organisms,
one member of a pair of matching chromosomes.
Homologous recombination:
Rearrangement of related DNA sequences on
a different molecule by crossing over in
a region of identical sequence.
Horizontal gene transfer:
Transmission of DNA between species, involving
close contact between the donor's DNA and
the recipient, uptake of DNA by the recipient,
and stable incorporation of the DNA into
the recipient's genome.
Hybrid: Seed or plants
produced as the result of controlled cross-pollination
as opposed to seed produced as the result
of natural pollination. Hybrid seeds are
selected to have higher quality traits (for
example, yield or pest tolerance).
Knock In: Replacement of
a gene by a mutant version of the same gene
using homologous recombination.
Knock Out: Inactivation
of a gene by homologous recombination following
transfection with a suitable DNA construct.
Labeling of foods: The
process of developing a list of ingredients
contained in foods. Labels imply that the
list of ingredients can be verified. The
U.S. Food and Drug Administration has jurisdiction
over what is stated on food labels.
Microinjection: The introduction
of DNA into the nucleus of an oocyte, embryo,
or other cell by injection through a very
fine needle.
Minimal tillage practices:
Practices that allow farmers to reduce the
tilling of the land to conserve topsoil and
its nutrients.
Molecular biology: A general
term referring to study of the structure
and function of proteins and nucleic acids
in biological systems. See Biotechnology
for the 21st Century: New Horizons for
more information.
Mutation: Any inheritable
change in DNA sequence.
Mutation breeding: Commonly
used practices in plant breeding and other
areas in which chemicals or radiation are
applied to whole organisms, for example plants,
or cells so changes in the organism's DNA
will occur. Such changes are then evaluated
for their beneficial effects such as disease
resistance.
Natural selection: The
concept developed by Charles Darwin that
genes which produce characteristics that
are more favorable in a particular environment
will be more abundant in the next generation.
Nuclear reprogramming:
Restoration of the correct embryonic pattern
of gene expression in a nucleus derived from
a somatic cell and introduced into an oocyte.
Nuclear transfer (NT):
The generation of a new animal nearly identical
to another one by injection of the nucleus
from a cell of the donor animal into an enucleated
oocyte of the recipient.
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). Thousands of nucleotides are linked
to form a DNA or RNA molecule.
Organic agriculture: A
concept and practice of agricultural production
that focuses on production without the use
of synthetic pesticides. See the USDA's National
Organic Program for an established a
set of national standards, which are available
online.
Ovule: An outgrowth of
the ovary of a seed plant that encloses an
embryo.
Pesticide resistance: A
genetic change in response to selection by
a pesticide, resulting in the development
of strains capable of surviving a dose lethal
to most individuals in a normal population.
Resistance may develop in insects, weeds,
or pathogens.
Phenotype: The visible
and/or measurable characteristics of an organism
(how it appears outwardly) as opposed to
its genotype, or genetic characteristics.
Plant-incorporated protectants:
Formerly referred to as plant-pesticides,
plant-incorporated protectants (PIPs) are
substances that act like pesticides produced
and used by a plant to protect it from pests
such as insects, viruses, and fungi.
Plasmid: A circular DNA
molecule capable of replication in bacteria.
Plasmids are the usual means of propagation
of DNA for transfection or other purposes.
Pleiotropy: A phenomenon
whereby a particular gene affects multiple
traits.
Pollen: The cells that
carry the male DNA of a seed plant.
Prion-related protein (PrP):
A normal protein, expressed in the nervous
system of animals, whose structure when altered
(by interaction with altered copies of itself)
is the cause of scrapie in sheep, BSE in
cattle, and Creutzfeldt-Jakob disease in
humans.
Prokaryote: Organisms,
namely bacteria and cyanobacteria (formerly
known as blue-green algae), characterized
by the possession of a simple naked DNA chromosome,
occasionally two such chromosomes, usually
of circular structure, without a nuclear
membrane and possessing a very small range
of organelles, generally only a plasma membrane
and ribosomes.
Promoter: A regulatory
element that specifies the start site of
transcription.
Pronuclear injection: The
use of a fine needle to inject DNA into the
nucleus of an unfertilized egg.
Protein: A large molecule
composed of one or more chains of amino acids
in a specific order. The order is determined
by the base sequence of nucleotides in the
gene that codes for the protein. Proteins
are required for the structure, function,
and regulation of the body's cells, tissues,
and organs; and each protein has unique functions.
Examples are hormones, enzymes, and antibodies.
Recombinant DNA molecules (rDNA):
A combination of DNA molecules of different
origin that are joined using recombinant
DNA technologies.
Recombinant DNA technology:
Procedure used to join together DNA segments
in a cell-free system (an environment outside
a cell or organism). Under appropriate conditions,
a recombinant DNA molecule can enter a cell
and replicate there, either autonomously
or after it has become integrated into a
cellular chromosome.
Recombination: The process
by which progeny derive a combination of
genes different from that of either parent.
Resistance management:
Strategies that can delay the onset of resistance.
For insect resistance management, this includes
the use of a refuge in which the insect will
not be challenged by the pesticide used in
the rest of the field.
Risk: The likelihood of
a defined hazard being realized, which is
the product of two probabilities: the probability
of exposure, P(E) , and the probability
of the hazard resulting given that exposure
has occurred, P(H/E) ( R =
P(E) x P(H/E)).
Scrapie: A disease, originally
of sheep, but transmissible to other animals,
characterized by neurological degeneration
caused by accumulation of a structural variant
of PrP.
Selectable marker: A gene,
usually encoding resistance to an antibiotic,
added to a vector construct to allow easy
selection of cells that contain the construct
from the large majority of cells that do
not.
Selective breeding: Making
deliberate crosses or matings of organisms
so the offspring will have a desired characteristic
derived from one of the parents.
Soil conservation practices:
See minimal tillage practices.
Somatic cells: Cells of
body tissues other than the germline.
Splicing: See gene splicing.
StarLinkTM: An insect-resistant
variety of corn that was approved for animal
feed only, not labeled for human consumption.
Tissue culture: A process
of growing a plant in the laboratory from
cells rather than seeds. This technique is
used in traditional plant breeding as well
as when using techniques of agricultural
biotechnology.
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 mutation breeding.
Transfection: Alteration
of the genome of a cell by direct introduction
of DNA, a small portion of which becomes
covalently associated with the host cell
DNA.
Transgenic: Containing
genes altered by insertion of DNA from an
unrelated organism. Taking genes from one
species and inserting them into another species
to get that trait expressed in the offspring.
Variety: Subdivision of
a species for taxonomic classification. Used
interchangeably with the term cultivar to
denote a group of individuals that is distinct
genetically from other groups of individuals
in the species. An agricultural variety is
a group of similar plants that by structural
features and performance can be identified
from other varieties within the same species.
Vector: A type of DNA,
such as a plasmid or phage that is self-replicating
and that can be used to transfer DNA segments
among host cells. Also, an insect or other
organism that provides a means of dispersal
for a disease or parasite.
Vertical transmission:
Inheritance of a gene from parent to offspring.
Virus: A noncellular biological
entity that can reproduce only within a host
cell. Viruses consist of nucleic acid covered
by protein; some animal viruses also are
surrounded by a membrane. Inside the infected
cell, the virus uses the synthetic capability
of the host to produce progeny viruses.
Vitamins: Various substances
that are essential in minute quantities to
the nutrition of animals and plants.
Xenotransplantation: Transplantation
of cells, tissues, or organs from one species
to another.
Zygote: A fertilized oocyte.
_____
Sources:
Agricultural Biotechnology: Informing the
Dialogue. Cornell University College of Agriculture
and Life Sciences: Ithaca NY. 2003.
National Research Council. Animal Biotechnology:
Science-Based Concerns. Washington, DC. 2003
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