Gregor Mendel

Gene that has been transferred naturally, or by any of a number of genetic engineering techniques, from one organism to another.

- Transgene

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Gene delivery

Process of introducing foreign genetic material, such as DNA or RNA, into host cells.

Bacterial transformation involves moving a gene from one bacteria to another. It is integrated into the recipients plasmid. and can then be expressed by the new host.
Electroporators can be used to make the cell membrane permeable to DNA
A gene gun uses biolistics to insert DNA into cells
A. tumefaciens attaching itself to a carrot cell
Foreign DNA being transduced into the host cell through an adenovirus vector.

This requires foreign DNA to be synthesized as part of a vector, which is designed to enter the desired host cell and deliver the transgene to that cell's genome.

Genetic engineering

Modification and manipulation of an organism's genes using technology.

Comparison of conventional plant breeding with transgenic and cisgenic genetic modification
In 1974 Rudolf Jaenisch created a genetically modified mouse, the first GM animal.
Polymerase chain reaction is a powerful tool used in molecular cloning
A gene gun uses biolistics to insert DNA into plant tissue
A. tumefaciens attaching itself to a carrot cell
Knockout mice
Human cells in which some proteins are fused with green fluorescent protein to allow them to be visualised
Products of genetic engineering
Bt-toxins present in peanut leaves (bottom image) protect it from extensive damage caused by lesser cornstalk borer larvae (top image).

If genetic material from another species is added to the host, the resulting organism is called transgenic.


Prevention of large-scale loss of biological integrity, focusing both on ecology and human health.

Positive-pressure biosafety suit
International Biohazard Warning Symbol

In agriculture (reducing the risk of alien viral or transgenic genes, genetic engineering or prions such as BSE/"MadCow", reducing the risk of food bacterial contamination)

Laboratory mouse

Small mammal of the order Rodentia which is bred and used for scientific research or feeders for certain pets.

Line drawing of a laboratory mouse
An albino SCID laboratory mouse
A laboratory mouse with intermediate coat colour
1-day-old pups
Two mice expressing enhanced green fluorescent protein under UV-illumination flanking one plain mouse from the non-transgenic parental line.
Comparison of a knockout Obese mouse (left) and a normal laboratory mouse (right).
A female C57BL/6 laboratory mouse
BALB/c laboratory mice
Laboratory mouse (note the ear tag)

There are hundreds of established inbred, outbred, and transgenic strains.

Gene gun

PDS-1000/He Particle Delivery System
A gene gun is used for delivery of exogenous DNA to cells. This method is known as 'biolistics'. Gene guns can be used effectively on most cells but are mainly used on plant cells. Step 1 The gene gun apparatus is ready to fire. Step 2 Helium fills the chamber and pressure builds against the rupture disk. Step 3 The pressure eventually reaches the point where the rupture disk breaks, and the resulting burst of helium propels the DNA/gold-coated macrocarrier ('Plastic Disk') into the stopping screen. Step 4 When the macrocarrier hits the stopping screen, the DNA-coated gold particles are propelled through the screen and into the target cells.

In genetic engineering, a gene gun or biolistic particle delivery system is a device used to deliver exogenous DNA (transgenes), RNA, or protein to cells.

Madras, Oregon

City in and the county seat of Jefferson County, Oregon, United States.

Bellamy House, Madras, Oregon seen in a real photo postcard c. 1920

In 2003, a Scotts Company large field trial of GMO bentgrass near Madras resulted in pollen spreading the transgene, which is Roundup resistant, over an area of 310 km2.

Genetically modified organism

Any organism whose genetic material has been altered using genetic engineering techniques.

A gene gun uses biolistics to insert DNA into plant tissue.
Herbert Boyer (pictured) and Stanley Cohen created the first genetically modified organism in 1973.
In 1974, Rudolf Jaenisch created the first genetically modified animal.
This artwork is made with bacteria modified to express 8 different colors of fluorescent proteins.
Tissue culture used to regenerate Arabidopsis thaliana
Suntory "blue" rose
Wild type peanut (top) and transgenic peanut with Bacillus thuringiensis gene added (bottom) exposed to cornstalk borer larva.
Kenyans examining insect-resistant transgenic Bacillus thuringiensis (Bt) corn
Golden rice compared to white rice
Some chimeras, like the blotched mouse shown, are created through genetic modification techniques like gene targeting.
Mice expressing the green fluorescent protein
Frog expressing Green fluorescent protein
Transgenic Hydra expressing Green fluorescent protein
A label marking this peanut butter as being non-GMO
Detail of a French cheese box declaring "GMO-free" production (i.e., below 0.9%)
A protester advocating for the labeling of GMOs

However it took another eight years before transgenic mice were developed that passed the transgene to their offspring.

Genetically modified mouse

Mouse (Mus musculus) that has had its genome altered through the use of genetic engineering techniques.

The genetically modified mouse in which a gene affecting hair growth has been knocked out (left), shown next to a normal lab mouse.
Transgenic mice expressing green fluorescent protein, which glows green under blue light. The central mouse is wild-type.

However, the mice did not pass the transgene to their offspring, and the impact and applicability of this experiment were, therefore, limited.

Molecular biology

Branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including molecular synthesis, modification, mechanisms, and interactions.

Diagrammatic representation of Watson and Crick's DNA structure
Angle description in DNA structure
Diagrammatic representation of experiment
Hershey and Chase experiment
Schematic relationship between biochemistry, genetics and molecular biology
DNA animation
Two percent agarose gel in borate buffer cast in a gel tray.
Proteins stained on a PAGE gel using Coomassie blue dye.
Northern blot diagram
Hybridization of target to probe

These blots are still used for some applications, however, such as measuring transgene copy number in transgenic mice or in the engineering of gene knockout embryonic stem cell lines.


Use of a glass micropipette to inject a liquid substance at a microscopic or borderline macroscopic level.

Diagram of the intracytoplasmic sperm injection of a human egg. Micromanipulator on the left holds egg in position while microinjector on the right delivers a single sperm cell.

Pronuclear injection is a technique used to create transgenic organisms by injecting genetic material into the nucleus of a fertilized oocyte.