(81)
12. Definere begreberne transgene dyr og transgene planter
Stryer, s.161; s.163
Devlin, s.319-321

Transgenic animals – animals that develop from a fertilized egg with an inserted foreign gene and carry that gene in every cell in their body.

The gene of interest is usually a cloned (seqeunce that is gonna be expressed in a new place/organisam) recombinant DNA molecule, which includes its own promoter. Multiple copies of the foreign gene are microinjected into the pronucleus of the fertilized egg. (pronucleus - 23 chromosomes made up of one chromatide).

The foreign DNA inserts randomly within the chromosomal DNA. If the insert disrupts a crucial cellular gene the embryo will die. Usually, non-lethal mutagenic events result from this insertion.     

Transgenic plants – new genes, not common to plants, may be engineered into plants that confer resistance to insects, fungi or bacteria. Also genes encoding existing structural proteins can be modified to contain essential amino acids not normally present in the plant, without modifying the function of the protein.

The potential to produce plants with new genetic properties depends on the ability to introduce genes into plant cells that can differentiate into whole plants.

Foreign DNA can be introduced in plant cells by plasmids of different bacteria, electroporation (application of intense electric fields to make the plants plasma membrane transiently permeable), gene guns – the DNA is packed into microprojectiles that are fired at the cell with great velocity. The last method is the most effective one.

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