Bacterial Transformation and Transduction

The experiment conducted by Boyer and Cohen was when E. Coli bacteria was transformed to be able ot incorporate virulent and resistant DNA from virulent strains. In transformation, DNA from the environment is absorbed into the bacterial cell. In transduction, a piece of DNA is transported in the cell by a virus. As A result of incorporating new genetic material, an organism can become resistant to antibiotics. E. COli was able to do this because of the adhesion zones. there are numerous small pores on the surface of E. Coli's cellular membrane. The lipeds repel the phosphates in the DNA plasmids. However, when they added the calcium ion, which had a positive charge, it made it relatively neutral. Lowering the temperature stabilizes the phospates. The heat shock makes the phosphates easier to hield. This makes it easier for DNA plasmids to enter the adhesion zones. In transduction, a virus inserts its RNA/ DNA into a bacterium which the bacterium may incorporate the viral DNA into its own DNA. The viral RNA/ DNA uses the bacterium's resoures to produce viral proteins and assemble new viruses. The new viruses will lysis the bacterial wal and splurge our, infecting other bacteria. An alternative is the bacteria incorporates the viral RNA/ DNA probably causing it to produce toxins, or it can lay dormant and be passed onto the bacterium's ofspring until environmental changes cause it to become active. We must recognize that some bacteria had been transformed by religated versions of the original plasmids. Therefore, Boyer and COhen were the first to produce recombinant plasmids.










REFERENCES:
http://www.dnalc.org/view/15916-DNA-transformation.html
google images