Image one	MICROBIAL GENETICS ©David B. Fankhauser, Ph.D., Professor of Biology and Chemistry University of Cincinnati Clermont College, Batavia OH 45103	Image Two
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Alcamo 155..., TFC 7^th, 211-242 & 253, 8^th: 211-243, Black 6^th: 173-229, Bauman 2^nd:

CENTRAL DOGMA of genetics discovered first in bacteria:

             DNA → RNA → protein. (electron micrograph: 216)

Processes:

             Replication (p. 203, 205) Bacterial chromosome circular, closed loop or rolling circle for plasmids

             Transcription (p. 209)

             Translation (p. 214-215)

In prokaryotes, all these processes occur in same general space, see p 216 for EM picture

             (eukaryotes perform first two in the nucleus and translation in cytoplasm):

REGULATION OF GENE EXPRESSION: Operon model (Jacob and Monod) (p. 218)

             Regulation of lac operon:           lacZ     B-galactosidase

                                                                  lacY     Permease

                                                                  lacA     transacetylase

                                                                 lacO     operator, binds the repressor

                                                                 lacI     repressor (allosteric protein, lactose inactivates)

Catabolite repression: When glucose is available, other catabolic pathways are shut down

             (preferentially use glucose, then switch to lactose. Show with break in growth curve, p 188.)

GENETIC VARIATION in bacteria via either mutation or recombination (similar to eukaryotes)

Differentiate: mutagen, mutagenesis, mutation, mutant

MUTATIONS: (p 221)

             base substitutions          transition vs transversion lead to missense or nonsense caused by:

                                                                 base analogs: 5FU, 5 BU, 2 AP, (p 222), UV (p. 224)

             frameshift                     (P 223) benzpyrene, aflatoxin, acridine dyes

             deletions                        nitrous acid, X rays, gamma rays, ionizing radiation

Ames test, (p. 227) auxotropic bacterium spread on minimal medium, prototrophic revertants appear

RECOMBINATION:

Transformation (p. 229): Griffith, 1928

             membrane made more permeable: 4°C in CaCl₂, heat to 42 with DNA

Transduction (Lederberg and Zinder in 1952) P22 virus of Salmonella (p 230)

Conjugation (p. 231-232) (Lederberg and Tatum, 1946; Jacob and Woolman in 1950s)

             F+ vs F- cells, plasmids, F pili, Hfr, sexduction (p 216)

             RTF:    p 217

GENETIC ENGINEERING: (p 241)

endonucleases: Ham Smith first isolated from Haemophilus influenzae (P 243)

Recombinant DNA: (p. 244)

             cut two different pieces of DNA with same restriction enzyme, recombinant DNA

             tie together with ligase

Boyer and Cohen perfected insertion fr S. aureus into E. coli. (See diagram on p ?? )