episomal vectors

[Ashok Aiyar]

On 25 Aug 1997 10:20:28 -0400,
Ian A. York (iayork at panix.com) wrote:

>Ashok mentions EBV/chromosomal origin vectors that replicate in mouse
>cells.  I'm not sure that these would be well-suited for library cloning,
>because (as I understand it, which might easily be wrong) these are fairly
>large vectors and you may have trouble getting representative and
>appropriately-sized inserts in them.

Ian, you are correct.  The average size of the genomic DNA insert in 
these plasmids is 10 - 15 kb, to which must be added another 8 kb of 
vector backbone containing the FR from oriP, EBNA-1, a tk-hyg cassette, 
and the ColE1 backbone; the Calos plasmids are derived from p220 from
Bill Sugden's lab.

Nevertheless they are reported to replicate in mouse/rat cells in a 
manner very similar to the replication of oriP plasmids in primate,
ungulate and canine cells, and I know that folks have tried using them
for gene delivery into mouse airway epithelium and lung cells.

Besides polyoma virus plasmids, another option to consider for rodent 
cells are BPV-1-origin or HPV- origin containing plasmids which do 
replicate stably in rodent cells the presence  of E1 and E2, but again 
the size of these plasmids are likely to be large.  If original poster 
chooses to go down this route, an appropriate lab to contact for plasmids 
would be that of Arne Stenlund at Cold Spring Harbor.

later,
Ashok
-- 
Ashok Aiyar, Ph.D.
McArdle Laboratory for Cancer Research
aiyar at ebv.oncology.wisc.edu