DNA cloning. Vectors (plasmids)
Genetic engineering: agriculture and environment
genetic engineering and medicine
Genetic engineering is a set of techniques that allow manipulation and transfer of genes from one organism to another. Thus we obtain genetically modified organisms. Transgenic organisms are those which has been inserted a gene, known as transgene from another organism.
DNA formed by joining DNA fragments from different organisms is called recombinant DNA.
CONSTRUCTION OF A RECOMBINANT DNA
The basic tools for the construction of recombinant DNA molecules are restriction endonucleases and DNA ligases.
The DNA can be cut into fragments by enzymes called restriction endonucleases. These DNA recognize specific frequencies and cut in specific places, so that the resulting fragments are (complementary) cohesive edges to other ends of DNA cut with the same enzyme.
The DNA ligase are enzymes that bind the cohesive ends of DNA fragments generated by restriction endonucleases. And they can be cut and join DNA fragments of different origin, thus it is possible to introduce a DNA into DNA of organisms other. The restriction enzymes are the scissors of DNA and DNA ligase the glue that binds the cut edges with scissors. There are more than one restriction enzyme and each recognizes and cuts a particular sequence in DNA.
