Principle 3- Part A Flashcards
_____ kills E. coli that do not invade.
Gentamycin
______does not penetrate mammalian cells.
Gentamycin
______ is used to identify certain genes that confer invasiveness on E. Coli
Genetic complementation
In order to prove that a specific gene promotes some action, is there usually a gain or loss of function mutation in genetic complementation?
Loss of function
A ____ plasmid can’t replicate in the original bacteria but can possibly replicate in another bacterium
Suicide plasma
How is the suicide plasmid containing inv loss-of-function mutation transferred from E. coli to Y.psuedotuberculosis
Sex pillus
How many recombination events are needed to replace the inv gene in Y. pseudotuberculosis with the loss-of-function inv allele?
2
_____ is a small, mobile piece of DNA
transposon
A ____ transposon is made up of a core area surrounded by an inverted repeated sequence sandwiched between direct repeat sequences flanking the IS
Simple transposon
A ____ transposon is made up of some sort of gene sandwiched between two insertion sequences
Composite transposon
Insertion of a transposon in a gene most often creates a ______ mutation
loss-of-function
A ______ marks the site of the mutation
Transposon
_____ determines which genes are virulence factors that encode exported genes
Tn-phoA mutagenesis
_____ gene encodes a periplasmic phosphatase
phoA gene
engineered phoA gene lacks ______ so expression depends on fusion to an adjacent gene after transposition
N-terminus
engineered phoA gene lacks N-terminus so expression depends on fusion to an adjacent gene ____ transposition
after
phoA has a substrate called ______
X-P dye
Vibrio cholerae virulence genes maximally expressed at pH ___ and ____ osmolarity
6.5 and high osmolarity
_____ is a screen for a negative trait
Signature-tagged mutagenesis
Genetic ______: examine individual bacteria for desirable trait
Screen
Genetic ______: only bacteria with desirable trait grow (Gentamycin selection in complementation assay)
Selection
Look for genes of S. typhimurium that are expressed in infection but not in the laboratory
This is only one strategy but it is doable.
Promoter-trapping (IVET: in vitro expression technology
In promoter-trapping, the promoter is needed for _____ to be expressed in mouse
Purine
_____ is doen in cells to sort them; usually uses macrophages to help to sort the bacteria
DFI: Differential fluorescence induction
