Gene Expression In Mammalian Cells

Question 0

What are the 4 mammalian expression systems?

Answer 0

Plasmid based
Inducible
Adenoviral
Retroviral

Question 1

What are the most common cell types used in mammalian expression systems?

Answer 1

Epithelial and fibroblast

Question 2

What are the advantages and disadvantages of a mammalian expression system?

Answer 2

\+ proper modifications 
\+ several vectors available
\+ well characterised
- low cell density
- slow expansion
- sensitivity
- expensive
- bovine proteins in culture media

Question 3

What are 4 ways of studying gene expression in mammalian cells?

Answer 3

DNA microarrays - compare effects of different treatments
Protein microarrays - study expression at protein level
RNAi - silence expression of a particular gene
Gene over expression - study effects of over expression

Question 4

What is the process of gene silencing by RNAi?
Gene expression silenced by addition of ___ to a cell.
Introduced by _________________
Processed into a short _______ by the enzyme ______
Multimeric protein / ___________ formed
Antisense _____ binds to ______
_______ bind to complementary sequence in mRNA
Targets mRNA for __________

Answer 4

Gene expression silenced by addition of DS-RNA to a cell.
Introduced by shuttle vectors or directly
Processed into a short 21-23bp siRNA duplex by the enzyme Dicer
Multimeric protein / siRNA complex formed
Antisense siRNA binds to RISC
Antisense siRNA bind to complementary sequence in mRNA
Targets mRNA for cleavage or degradation