AGR 3303 Lecture Notes - Lecture 5: Genetic Engineering, Streptomycin, Auxotrophy
24 Jan 2019
School
Department
Course
Professor
Document Summary
Lecture 5 bacterial and viral genetic systems 01/22/19 . Bacterial and viral genetics: bacteria and viruses are excellent models for genetic studies, rapid reproduction, many progeny, small genomes, growth in laboratory is easy and requires little space. 3 mechanisms of genetics exchange among bacteria: conjugation, transformation, transduction. Small circular dna molecule with their own origin of a replication. High copy number plasmids -> up to 50 copies per cell. Low copy number plasmids -> one or two copies per cell. Can provide selective advantage to the bacterium. Ex: being antibiotic resistant allowing the bacterium to grow and withstand difficult conditions. Experiment determining conjugation is cell to cell contact. Auxotrophic strain in minimal media showed no growth. Even if separated by a filter but not allowing mixing there was no growth because no contact. cells. Dna: cell division, transformed cell: double stranded dna plus transformed dna, non-transformed cell, slide 12 shows process.
