BIOL 200 POST MIDTERM.docx - BIOL 200 POST MIDTERM Lecture 17(Chapter 6 E coli and bacteriophage lamba are the workhorses of molecular biology Purified

BIOL 200 POST MIDTERM.docx - BIOL 200 POST MIDTERM Lecture...

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BIOL 200 POST MIDTERM Lecture 17 (Chapter 6) E. coli and bacteriophage lamba are the workhorses of molecular biology - Purified enzymes E. coli and bacteriophage lamba facilitated the rapid progress in our understanding of molecular biology - Paul Berg and others were the first to successfully introduce exogenous DNA fragments into bacteria to produce a recombinant gene product - Stanley Cohen and Herbert Boyer introduced novel bacterial resistance genes - This milestone in the era of recombinant DNA technology (genetic engineering) and the birth of biotechnology - Today many recombinant drugs are being used to treat countless numbers of diseases (diabetes, dwarfism, haemophilia) - Conserved mechanism of gene expression shared amongst organisms - Something went right way back that was maintained - All use same kind of principles to express genes Clone: A group of organisms produced from one stock or ancestor, one such organism, person or thing regarded as identical to another, propagate as a clone - Because it can mean slightly different things in different situations Developmental biology - Allow cell division to take place then mechanically separate the blastomeres then allow those blastomeres to develop on their own - Give rise to fully functional organisms - Tadpole, remove nuclei from intestine and reintroduce nuclei into an organism that’s been innuclei - Nuclei get reprogrammed and eventually give rise to fully grown organisms - Clone mammalian organisms like Dolly - Took nucleus from mammary adult cell and put it back into a very early embryo - Clone genes: important for specific entities or mechanisms or part of our body - Antannapedia gene (in flies) gives rise to legs that grow out of head - Use genetics to identify where the mutation is - Find the sequence and then work with it - Isolate region of DNA - Reintroduce it in a lonely bacterium - Every time this cell divides it gets this that new gene 1
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Bacterial restriction enzymes cut DNA at specific sites - EcoR (and other enzymes like it) cuts DNA at a specific six nucleotides, palindromic sequence (GAATTC) - Overhanging ends that are fully complementary are “cohesive” or “sticky” - Specialized plasmids called vectors were engineered to carry out specific functions - Cut DNA out of initial site in the genome and reintroduce it into an autonomous recombinant DNA called a plasmid - Use restriction enzymes cites to cut genome and take the pieces out and the important pieces that correspond to the gene gets inserted into the plasmid - Ends are sticky because of those restriction enzyme sites - Confers ampicillin resistance - In labs ampicillin is engineered Differential digestion facilitates directional insertion of desired DNA at specific sites - Digestion of a vector with two different enzymes facilitates directional cloning - Poly Linker – multiple cloning site - There are number of restriction enzyme sites - Open plasmid to shuttle pieces of DNA into that site - Works best when cut with two different enzymes - Can go in one or two orientations -
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