Week 3 - Phage's pt 2

Question 1

Give an overview of Phage M13

Answer 1

its a filamentous phage, with a F-pilus tip protein for receptor, and the infectous cycle results in contiual release of phage virions without the lysis of the host cell

Question 2

M13 has 2 forms, what are they?

Answer 2

SS present in mature phage and DS that behaves like a plasmid and can be treated as one

M13 is an example of an phagemid

Question 3

What are phagemid vectors?

Answer 3

they contain characteristics from phage and plasmids
can be switched to phage mode of replication via the introduction of a helper phage (WTM13)

Question 4

List different types of high-capacity vectors

Answer 4

Cosmids - cross of Lambda phage and plasmid - 35 - 45 kbp
P1-derived - 70-100 kbp
PAC - 80-100 kbp
BAC - 150-300 kbp
YAC - >300 kbp

Question 5

What are cosmids?

Answer 5

cross between phage and plasmid, is essentially a plasmid which contains one or more cos sites, no phage DNA apart from the cos sites so cells are not lysed.

Question 6

What are P1 and PACs?

Answer 6

P1 is an E. coli bacteriophage that is 94 kbp long, and exists as a plasmid, PACs are P1 artificial chromosomes vectors that permit cloing of larege DNA fragments

Question 7

What are BACs?

Answer 7

Bacterial Artificial Chromosomes - Are artificial chimeric DNA molecules, usually small being 7 kbp, naturaly stable permits cloning of large pieces of DNA, can carry 100-300 kbp

Question 8

What are YAC vectors

Answer 8

yeast Artificial chromosomes - can carry 1000kbp, resemble normal yeast chromosomes, yeast is the host cell used not E .coli

Question 9

How are the following vectors introduced into cells:
Cosmids
P1
PAC
BAC
YAC

Answer 9

Cosmids - transduction
P1 - transduction
PAC - Electroporation
BAC - Electroporation
YAC - Electroporation or transformation