English: Bacterial Transformation

In this diagram, a gene from bacterial cell 1 is moved from bacterial cell 1 to bacterial cell 2. This process of bacterial cell 2 taking up new genetic material is called transformation.

Step I: The DNA of a bacterial cell is located in the cytoplasm (1), but also in the plasmid, an independent, circular loop of DNA. The gene to be transferred (4) is located on the plasmid of cell 1 (3), but not on the plasmid of bacterial cell 2 (2). In order to remove the gene from the plasmid of bacterial cell 1, a restriction enzyme (5) is used. The restriction enzyme binds to a specific site on the DNA and “cuts” it, releasing the satisfactory gene. Genes are naturally removed and released into the environment usually after a cell dies and disintegrates.

Step II: Bacterial cell 2 takes up the gene. This integration of genetic material from the environment is an evolutionary tool and is common in bacterial cells.

Step III: The enzyme DNA ligase (6) adds the gene to the plasmid of bacterial cell 2 by forming chemical bonds between the two segments which join them together.

Step IV: The plasmid of bacterial cell 2 now contains the gene from bacterial cell 1 (7). The gene has been transferred from one bacterial cell to another, and transformation is complete.