Central Dogma of Molecular Genetics Restriction-Modification Systems of Bacteria Cloning Vectors cDNA Cloning Clone Library Screening DNA Sequencing Southern and Northern Analysis Exons and Introns Polymerase Chain Reaction (or PCR) Study Questions Cloning and Molecular Analysis of Genes WWW Links Genetic Topics

Central Dogma of Molecular Genetics The most significant recent development in genetics has been the introduction of molecular tools for genetic analysis. These techniques are based on the Central Dogma of Molecular Genetics. DNA--------->RNA--------->Protein This diagram depicts the flow of genetic information from DNA into protein, the molecule most often associated with a specific phenotype. The three molecular events that maintain the genetic integrity and convert DNA information into a protein molecule are replication, transcription and translation. For some viral species, reverse transcription is also important. Each of th ese events are enzymatically driven and some of the enzymes involved in these steps are important for molecular studies. In particular these enzymes are: DNA polymerase - synthesizes DNA from a DNA template; used to radiolabel DNA probespolymerase chain reaction and cDNA cloning DNA ligase - forms a covalent bond between free single-stranded ends of DNA molecules during replication; used for DNA cloning Reverse transcriptase - synthesizes DNA from a RNA template; used primarily for cDNA cloning Although these enzymes are important for molecular cloning, they are not the only ones that are important. They are listed here primarily to emphasize that the study of the basic processes of life can also have an applied usage. Copyright © 1997. Phillip McClean