Deep surveying of alternative splicing complexity in the human transcriptome by high-throughput sequencing

Area of Science:

• Genomics
• Molecular Biology
• Bioinformatics

Background:

• Alternative splicing is a key mechanism for increasing proteomic diversity from a limited genome.
• Understanding the complexity of alternative splicing in human tissues is crucial for comprehending gene regulation and disease.

Purpose of the Study:

• To conduct the first comprehensive analysis of alternative splicing complexity in human tissues.
• To identify novel splice junctions and quantify alternative splicing events using mRNA-Seq data.
• To validate the reliability of mRNA-Seq for measuring exon inclusion levels.

Main Methods:

• Utilized mRNA-Seq (messenger RNA sequencing) data for analysis.
• Combined mRNA-Seq data with EST-cDNA (expressed sequence tag-complementary DNA) sequence data.
• Compared mRNA-Seq results with quantitative alternative splicing microarray profiling data.

Main Results:

• Detected new splice junctions in approximately 20% of multiexon genes, with many showing tissue-specific patterns.
• Estimated that around 95% of multiexon genes undergo alternative splicing.
• Identified approximately 100,000 intermediate- to high-abundance alternative splicing events in major human tissues.
• Demonstrated that mRNA-Seq provides reliable measurements for exon inclusion levels.

Conclusions:

• Alternative splicing is a highly complex and pervasive process in human tissues.
• mRNA-Seq is a robust technology for analyzing alternative splicing events.
• The findings provide a foundation for further research into the functional and regulatory roles of alternative splicing.