Unit 3: Regulating mRNA Stability in Eukaryotes

Question 1

The stability of the mRNA affects what biological process?

Answer 1

How much translation occurs.

Question 2

What is the general lifespan of mRNA molecules?

Answer 2

mRNA molecules don’t last forever; they are eventually degraded. How long an mRNA sticks around to be translated varies from minutes to longer than a day. Most human mRNAs last hours.

Question 3

What cellular components can influence the lifespan of mRNA molecules?

Answer 3

Processes and molecules in the cytoplasm can be important regulators of gene expression.

Question 4

Provide an example of an mRNA whose lifespan can vary depending on the cell type. What protein does it code for?

Answer 4

mRNAs for casein (a milk protein).

Question 5

What is the approximate half-life of casein mRNA in the mammary glands of non-lactating female mouse?

Answer 5

1 hour.

Question 6

What is the approximate half-life of casein mRNA in the mammary glands of a lactating female mouse?

Answer 6

28.5 hours.