Regulation of Gene Expression

If every somatic cell has the same genes…why are only some genes expressed in certain cells and not others? 

If every somatic cell has the same genes…why are only some genes expressed at certain stages in life (e.g. baby vs adult)?

Verbally describe the main stages of the central dogma where the expression of genes can be regulated/modified?

(hint: use the figure of the “eukaryotic gene expression” cell to guide you) 

What is the differences between acetylation and methylation? How are they similar? 

What modifications are made to chromatin to either induce or suppress expression? What process is being induced of expressed? 

Describe what happens to an organism’s DNA if epigenetic tags are added? Why does this matter for subsequent generations if it’s not the genes, themselves, that are changed? 

Understand the interaction between specific transcription factors and enhancer sites for differential gene expression.  Give hypothetical example of…genes for acid production in your stomach versus genes for mucus production in your nose. 

How can the body/cell use transcription factors to coordinate the expression of different genes needed for a particular process? 

Explain how alternative splicing can lead to different mature mRNA from the same pre-mRNA. 

If an mRNA strand has the “incorrect” 5’-cap and/or 3’-tail, what would you predict would happen for the next step of transport out of the nucleus? 

Let’s say this mRNA gets out of the nucleus, but the cell needs to destroy it.  

What are the two types of small, regulatory non-coding RNAs that can do this?  

Let’s say this mRNA gets out of the nucleus, but the cell needs to destroy it.  

What protein complex are they a part of? 

Let’s say this mRNA gets out of the nucleus, but the cell needs to destroy it.  

Why would having a complementary sequence be important for targeting the correct mRNA? 

Well, shoot – that mRNA was translated into a polypeptide, but we don’t want that protein being expressed!

What molecule can tag that protein for destruction? 

Well, shoot – that mRNA was translated into a polypeptide, but we don’t want that protein being expressed!

What structure will actually degrade that protein? 

Well, shoot – that mRNA was translated into a polypeptide, but we don’t want that protein being expressed!

What are other ways the cell can regulate the expression of the protein?