Unit 3: Alternative mRNA Splicing in Eukaryotes

Question 1

Alternative mRNA Splicing.

Answer 1

A process where primary RNA transcripts (pre - mRNA) from a single gene can be spliced in different ways to produce multiple mature mRNA molecules. This involves including or excluding different exons, or parts of exons, along with the introns.

Question 2

What is the estimated percentage of human genes that undergo alternative mRNA splicing?

Answer 2

More than 90% of humans.

Question 3

Outcome of Alternative mRNA splicing.

Answer 3

Different mature mRNA molecules are produced from the same gene. These different mRNAs can then be translated into protein isoforms, which may have different structures and functions.

Question 4

Example: ATP Synthase mRNA Splicing.

Answer 4

Alternative splicing of ATP synthase mRNA leads to different forms of the ATP synthase protein found in muscle cells versus non- muscle cells.

Question 5

Immunoglobulin Heavy Chain (Igh) mRNA Splicing in B cells.

Answer 5

Alternative mRNA splicing of Igh mRNA plays a role in B cells switching from producing membrane- bound IgH proteins (B - cell receptors) to producing soluble IgH proteins (secreted antibodies).