BIO 198 Chapter Notes - Chapter 6: Growth Medium, Horizontal Gene Transfer, Rolling Circle Replication
Document Summary
Bacteria are good for genetic study genome simplicity, uncomplicated genotypes, short generation times, large number of progeny, ease of propagation, numerous heritable differences. Conjugation identified: lederberg and tatum used triple-auxotrophic strains of e. coli that require different nutrients to grow. Each strain grew on its own and one together on full media. Then, the colonies were transferred on minimal media. Plates with either of the two had no growth, but plates with both grew in minimal media. They later proved that physical contact was necessary for this revertant nature. Hfr chromosome: high frequency recombination donor strains that transferred donor bacterial genes to recipient bacteria at an extraordinarily high rate; occurs when the the f factor is joined into the bacterial chromosome between an is site. Hfr gene transfer: hfr gene transfer occurs just like the f transfer because the protein cleaves at orit and then it takes the linear chromosome to the recipient cell through the conjugate pilus.
