Transformation,conjugation and transduction: scientists, experiments and general info Flashcards
who discovered transformation?
Griffith in 1928
What was griffith’s experiment and what did he discover?
discovered transformation. observed virulent strains were smooth (LPS) and mixed heat killed smooth and non virulent and mouse still died.
Who showed the transformation principle was DNA in 1944?
Avery,Macleod and McCarty
what is PLQ?
pores that allow DNA to reach import system in transformation
what is ComEA protein?
protein that allows reception on dsDNA to cell surface (transformation)
what moves through COME?
ssDNA
what enzymes were used to show DNA was the transformation principle?
RNase,protease an DNAase
what are 2 artificial transformation methods?
Cacl2 and electroporation
what does a polylinker contain?
unique restriction sites for inserting foreign DNA
what did Agnes Ullman discover?
blue/white screening
what did Lederberg and Tatum discover?
conjugation
what organism did Lederberg and Tatum use to discover conjugation?
auxotrophic e.coli
what is an episome?
dna that can be in a plasmid form or integrated
is an F factor an episome?
YES
what are IS and where are they found?
insertion sequences found in the F plasmid
who carried out the interrupted mating experiment using a blender?
Jacob and Wollman
when was the interrupted mating experiment first carried out and by who?
Jacob and wollman in 1957
what does dilution help do in interrupted mating experiments?
stops new matings and determines start time
what are the first genes to be transferred in interrupted mating experiments?
F factor genes
T or F:the closer the gene is to the OriT the slower it will be transferred?
FALSE it will be quicker the closer it is to OriT
what genes are for the production of the pilus?
tra genes
does the probability of mating cells breaking increase or decrease over time?
increase
the later the gene enters the recipient cell the smaller the frequency of recombinants: T or F
True as the probability of the two mating cells breaking increases with time (PRODUCING a new HFR from HFR and F- is very low as F- rarely receives entire F factor)
what does high resolution mapping use?
recombinant frequencies
what is a prophage?
temperate bacteriophage integrated into host bacterium’s chromosome
what is a temperate phage?
phage that uses lytic or lysogenic cycle
what is cotransduction?
transduction involving 2 or more genetic loci by a single phage( phage picks up as single piece of DNA as the genes are close together)
who discovered transduction?
Josh Lederberg and Norton zinder
Who are Josh lederberg and Norton zinder?
scientists that discovered transduction
what experiments did lederberg and zinder carry out and what did they discover?
transduction through experiments with Salmonella typhirurium. They discovered recombinants from u tube and varied pore size to discover agent was P22 virus
what is p22?
a temperate phage of salmonella typhirurium
how did lederberg and zinder know the filterable agent in their experiment WAS P22?
they both had the same properties 1)size 2)antiserum sensitivity 3)immunity to hydrolytic enzymes
what is the lander phage an example of?
a specialised temperate phage
where does the lander phage always insert into and why?
between gal and bio region of host chromosome to ensure it is always integrated at the same point so when the lytic cycle is induced it can be excised precisely to create circular lander chromosome (can then remain in lysogenic cycle)
what is the lytic cycle induced by?
UV
