GENET270 Lecture Notes - Lecture 1: Classical Genetics, Reverse Genetics, Model Organism
Document Summary
3 domains of life: archaea, bacteria, eukaryotes. Bacteria: differ greatly in shape and life-cycle, single-celled or multi-cellular, predominantly rod-shaped or spherical. Streptomyces: form stalks (hyphae) of spores, produce antibiotics. E. coli: single-celled rods, model organism and pathogen in research. Genes wrapped in protective protein or membrane coat. Not alive, need host bacteria cell to multiply. They can only create progeny when they infect a bacterium. Most common entities on earth (10^9 in microbial sea water mats) Isolate mutants affected in a particular function: study the mutated genes. Reverse genetics: start with a known gene, mutate it in-vitro, return it to the organism, study the affected functions. *requires prior knowledge of the gene being mutated. Prototrophs: wild type strain that can grow on minimal media. Auxotrophs: cannot create all essential macromolecules necessary for growth, requires complex media or minimal media supplemented with missing ingredient.