Related Experiment Video
Updated: Jun 12, 2026
07:02
Evaluation of Exon Inclusion Induced by Splice Switching Antisense Oligonucleotides in SMA Patient Fibroblasts
Published on: May 11, 2018
High-throughput analysis revealed mutations' diverging effects on SMN1 exon 7 splicing
Přemysl Souček1,2, Kamila Réblová1, Michal Kramárek2
1Medical Genomics RG, Central European Institute of Technology, Masaryk University , Brno , Czech Republic.
RNA Biology
|June 20, 2019
Summary
Splicing-affecting mutations disrupt gene function. This study reveals that creating new splicing enhancers near mutated splice sites drives cryptic splice site usage, impacting gene transcript assembly.
Area of Science:
- Molecular Biology
- Genetics
- RNA Biology
Background:
- Splicing-affecting mutations alter gene function by changing transcript assembly.
- Understanding splicing dysregulation is crucial for genetic disease research.
Purpose of the Study:
- To investigate splicing dysregulation principles using a high-throughput minigene assay.
- To evaluate the impact of single-nucleotide and double-nucleotide mutations on SMN1 exon 7 splicing.
Main Methods:
- Developed a modified minigene assay for parallel, high-throughput mutation evaluation.
- Utilized next-generation sequencing to analyze splicing outcomes.
- Systematically mutated all exonic and intronic positions of SMN1 exon 7.
Main Results:
- Mutations caused a spectrum of splicing aberrations, including exon skipping and cryptic splice site activation.
- Disrupting exonic splicing enhancers did not always lead to exon skipping, suggesting functional redundancy.
- Mutations at the 5' splice site (5'ss) could activate cryptic 5'ss, often associated with increased pre-mRNA/U1 snRNA duplex stability and regulatory element strength.
Conclusions:
- Creating new splicing enhancers at mutated 5'ss is a key driver of cryptic 5'ss use.
- Splicing regulatory elements play a predominant role in determining splicing outcomes.
- U1 snRNA binding may contribute to the balance of splicing isoforms.
Related Concept Videos
01:32RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
02:18Alternative RNA Splicing
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
02:32Exon Recombination
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Exon shuffling follows “splice frame rules.” Each exon has three reading...
01:30Spontaneous and Induced Mutations
Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base).
01:30Point and Frameshift Mutations
Point mutations are genetic alterations involving the change of a single nucleotide base pair in DNA. Depending on how the alteration affects protein synthesis, they can lead to various consequences.Point mutations fall into the following types:Silent mutations occur when a nucleotide change does not alter the amino acid sequence due to the redundancy of the genetic code. For instance, changing ACC to ACA still encodes threonine, leaving the protein function unaffected. This occurs because...