received by the International Bureau on 14 April 2014 (14.04.2014)

We claim:

An expression vector for animal cells comprising:

a) at least one promoter ;

b) at least one matrix attachment region ;

c) at least one gene encoding a stress resistance protein ;

d) at least one gene encoding a selection marker other than stress resistance protein e) at least one gene encoding an expression protein ;

f) optionally at least one internal ribosome entry site ; and

g) a transcription terminator ;

wherein all these are operably connected to each other.

The expression vector as claimed in claim 1 wherein expression vector is comprised of a polynucleotide sequence of sequence id 1.

The expression vector as claimed in claim 1 wherein promoter is PEF 1 alpha promoter, hCMV promoter or HSP promoter.

The expression vector as claimed in claim 3 wherein promoter is PEF 1 alpha promoter.

The expression vector as claimed in claim 1 wherein gene encoding expression protein , encodes any recombinant protein of therapeutic or non-therapeutic significance expressed in mammalian cell.

The expression vector as claimed in claim 1 wherein internal ribosome entry site (IRES) is Picornavirus IRES, Aphthovirus IRES, Hepatitis A IRES, Hepatitis C IRES, Pestivirus IRES, Cripavirus IRES, Kaposi sarcoma associated herpesvirus IRES or combination thereof.

The expression vector as claimed in claim 1 and claim 6 wherein internal ribosome entry site (IRES) is linked to gene encoding the selection marker.

The expression vector as claimed in claim 1 wherein stress registance gene encodes for stress protein HSP 70, HSP 90, HSP27 or combination thereof.

9. The expression vector as claimed in claim 8 wherein stress registance gene encodes for HSP27 protein.

10. The expression vector as claimed in claim 1 wherein selection marker is glutamine synthatase, dihydrofolate reductase, antibiotic resistance, auxotrophic markers or combination thereof.

1 1. The expression vector as claimed in claim 10 wherein selection marker is dihydrofolate reductase.

12. The expression vector as claimed in claim 1 wherein matrix attachment region (MAR) is of human, xenopus, mouse or any other plant or animal source.

13. The expression vector as claimed in claim 12 wherein matrix attachment region (MAR) is chicken lysozyme MAR element.

14. The expression vector as claimed in claim 1 wherein transcription terminator is bovine growth hormone polyadenylation signal.

15. The expression vector as claimed in claim 1 wherein animal host cell is mammalian host cell selected from but not restricted to mammalian stem cells, mammalian embryonic stem cells, CHO cells, baby hamster kidney cells, myloma cells or any other differentiated and undifferentiated mammalian cells.

16. The expression vector as claimed in claim 1 wherein expression vector is expressed in mammalian host cell to produce stable cell lines.

17. Expression vector as claimed in claim 1 and claim 16 wherein stable mammalian host cell lines are used to produce protein of interest.

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