BIO370Y5 Lecture Notes - Lecture 5: Escherichia Coli, Lysine, Bacteriophage
Document Summary
Can happen by breakage and rejoining or by crossing over between repetitive dna. Deletion mutation: loss of dna: difference scale of frameshift, requires two breaks in dna to cut out intervening segment. Inversion: reversal of gene order (3" becomes 5") and the enzyme doesn"t know how to repair it cause it cant tell which side is which. Insertion (translocation): move one piece of dna somewhere else: transposable elements: does the moving for the above macrolesion. Can determine sit of action of external agents. Can show how proteins react directly or indirectly. Mutations are rare: 1 in 107 to 109 bp/cell generation. Detect them by screening: use replica plating or color and size and stuff. Fluctuations test by luria and delbruck 1943: showed that variation happens spontaneously and not by selective agent and used this. If plated with phage t1 (109 cells) most will die but rare ones will survive.
