Comprehensive identification of alternative back-splicing in human tissue transcriptomes

Area of Science:

• Molecular Biology
• Genomics
• RNA Biology

Background:

• Circular RNAs (circRNAs) are formed by back-splicing.
• Alternative back-splicing (ABS) allows a single gene to produce multiple circRNAs.
• The prevalence and regulation of ABS in human tissues are not well understood.

Purpose of the Study:

• To analyze the extent and tissue specificity of ABS events in human transcriptomes.
• To investigate the regulatory factors associated with ABS complexity.
• To provide a comprehensive resource for circRNA research.

Main Methods:

• Analysis of alternative back-splicing (ABS) events in 90 human tissue transcriptomes.
• Comparative analysis of ABS prevalence and patterns across different tissues, especially brain regions.
• Correlation analysis between ABS complexity and genomic features like intron length and Alu element abundance.

Main Results:

• ABS was detected in approximately 84% of analyzed circRNAs.
• Alternative 5' back-splicing was more common than alternative 3' back-splicing.
• ABS events are tissue-specific, with higher complexity observed in brain tissues.
• Intron length and Alu element abundance positively correlated with ABS complexity.

Conclusions:

• ABS is a major contributor to circRNA diversity across human tissues.
• Brain tissues exhibit unique and complex ABS patterns.
• Genomic features, including intron length and Alu elements, influence ABS.
• This study expands the known repertoire of ABS events and offers insights into circRNA regulation.