Lecture28

Brandl – Lecture 5 Notes Recombinant DNA technology:  The techniques which allow DNA fragments from different sources (different chromosomes, different organisms, or man-made) to be recombined to make new DNA molecules with unique features  Humans have been manipulating DNA for a long time using selective breeding  In the 70’s DNA was hard to work with at the molecular level o Individual genes are contained amongst other genes in a long, linear polymer o The composition of most DNA’s are similar as they are composed of only 4 bases, therefore, traditional biochemical approaches were not well suited for separating and analyzing individual genes o Now the manipulation of genes in the lab is easy using the tools of recombinant DNA technology Comparison of classical genetic techniques and RDT Classical genetics Recombinant DNA technology Slow: limited by the breeding Rapid: as quick as a few days in some organisms time of the organism and chance genetic events Limited to breeding species No limitations – you can put a human gene in bacteria SIGNIFICANCE OF RECOMBINANT DNA TECHNOLOGY  In Research:  Has allowed the rapid expansion of scientific knowledge o In not only areas of gene structure (promoter and origin mapping, intron- exon structure, etc) and function (transcription, splicing, transposition, replication, translation) but in all areas of biochemistry and cell biology  Power of RDT directly reflects the link between genes and proteins as defined in the Central Dogma  RDT has thus introduced a novel way to study protein structure and function most notably in the form of site directed mutagenesis, protein over-expression, and protein engineering  With the use of computational science, RDT has also enabled the analysis of whole genomes (bioinformatics) – genome sequencing projects o The complete genome sequences of many hundreds of organisms are now known Biotechnology:  Biotechnology: the use of organisms to do work for man  The impact on human health is evident in diverse areas, but most notably in the pharmaceutical industry and in agriculture  RDT has a major impact in biotechnology because: o It has enabled the production of large amounts of otherwise rare proteins o The techniques to introduce genes across species barriers have been developed o RDT has allowed the creation of novel proteins and even modified organisms  Areas where RDT has allowed dramatic changes in biotechnology: 1. Medicine o Drug production and creation (e.g. vaccines, human insulin, growth hormone, artemisinin/ malaria, interleukins, Factor VIII) o Diagnosis – detect pathogens and disease causing genes through their DNA signatures (e.g. PCR technique is used to detect HIV) o Genetic counseling and screening – does an individual carry a disease related allele o Potential for gene therapy – add back functional genes in replacement for defective gene to cure disease (e.g. cystic fibrosis) – this is complicated in terms of the gene delivery but is on the rise 2. Agriculture o Production of crops with unique features (production of novel molecules in plants)… - Large scale production of Therapeutic drugs - Production of or