BIO 326R 1st Edition Lecture 17 Outline of Last Lecture I. Making a Plasmida. Conjugation, transformation, transductionII. Conjugationa. Self transmissibleb. Mobilizable plasmidc. Genes usedi. Tra genesii. Mob genesiii. OriTIII. Transformationa. Natural, artificial, electroporationOutline of Current Lecture I. Transductiona. Generalized transductioni. Lytic bacteriophageb. Homologous recombinationc. Transposonsi. Inverted repeatsii. transposaseCurrent LectureTransduction- see powerpoint slides for more details on transduction- generalized transductionThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o bacteriophage (phage) = are obligate intracellular parasites that multiply inside bacteria by making use of some or all of the host biosynthetic machinery (i.e., viruses that infect bacteria) o lytic bacteriophage= lyses prokaryotic bacteria absorbs to a susceptible bacterium bacteriophage genome enters the bacterium- the genome directs the bacterium’s metabolic machinery to manufacture bacteriophage components and enzymes- in E. coli, receptors recognize lipd A and bind specificallyo P1 phage is the most common—makes 1 in 1000 mistakes 1 in 1000 have chromosomal DNA ~2% of E. coli chromosomeo Packages own viral genome bacteriophage head or capsid occasionally assembles around fragment of donor bacterium's nucleoid or around a plasmid instead of a phage genome by mistake bacteriophages are released bacteriophage carrying donor bacterium’s DNA adsorbs to a recipient bacterium The bacteriophage inserts the donor bacterium's DNA it is carrying into the recipient bacterium . The donor bacterium's DNA is exchanged for some of the recipient's DNA.o Antibiotic resistance gene marker on DNA piece is used for bacteriophage to select for DNA- Homologous recombination= crossing overo At cross over, genes are the sameo New/different genes get incorporated between cross over sites- Transposonso “jumping genes”= 1983 Nobel Prizeo DNA elements that can hop from one location to anothero Transposon mutagens are used as a screening tool for finding genes of interest Where are antibiotic resistance (Ab^r) geneso DNA strand: -----IR-----Ab^r-----IR----- IR= inverted repeat (palindromic)- 5’-CCCTTTATAAAGGG-3’3’-GGGAAATATTTCCC-5’ Transposase= trans acting factor- Enzyme that promotes transposition (movement) of a transposon recognizes the IR Cut and paste transposons= cut out the transposon and pastes it somewhere else- Screening
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