Summary
Different exon combinations from one gene yield several protein variants.
In depth
About 95 percent of human multi-exon genes are alternatively spliced, expanding about 20,000 genes into many more proteins. Different tissues choose different isoforms.
Mis-splicing is linked to cancer and neurological disease.
Types include exon skipping (the most common in humans), mutually exclusive exons, alternative 5 prime or 3 prime splice sites and intron retention. In Drosophila, the Dscam gene can produce over 38,000 isoforms, giving neurons distinct identities. The calcitonin gene makes calcitonin in the thyroid and CGRP in neurons through tissue-specific processing.
Splicing patterns are regulated by RNA-binding proteins and respond to signals, and they change in cancers. Some therapies target splicing to produce desirable isoforms.
Example: sex determination in fruit flies depends on a cascade of alternative splicing events in the Sxl, tra and dsx genes.
Frequently asked questions
What is Alternative Splicing?
Different exon combinations from one gene yield several protein variants.
Which area of biology covers Alternative Splicing, and how advanced is it?
Alternative Splicing is one of the 52 topics in Molecular Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Splicing, Enhancers and Silencers, Transcription Factors.
Can you give an example of Alternative Splicing?
The Drosophila Dscam gene can create over 38,000 isoforms.
What should I learn before Alternative Splicing?
Work through the Beginner topics in Molecular Biology first, such as Central Dogma, DNA Replication, Base Pairing, then return to Alternative Splicing. Intermediate topics assume the Beginner vocabulary.
What topics are related to Alternative Splicing?
The closest topics to Alternative Splicing are Splicing, Enhancers and Silencers, Transcription Factors, Gene Expression. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Alternative Splicing?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Alternative Splicing. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
How is Alternative Splicing different from Splicing?
Alternative Splicing: Different exon combinations from one gene yield several protein variants. Splicing: The removal of introns and joining of exons by the spliceosome to produce mature mRNA. Read both side by side and note what each one explains.
How should I study Alternative Splicing step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Splicing and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.