Identification of Transposable Elements Contributing to Tissue-Specific Expression of Long Non-Coding RNAs

Area of Science:

• Genomics
• Molecular Biology
• Bioinformatics

Background:

• Transposable elements (TEs) are increasingly recognized for their functional roles beyond genomic mobility.
• Long non-coding RNAs (lncRNAs) are a class of RNA molecules with diverse regulatory functions.
• The reuse of TEs within lncRNAs, particularly in maintaining human embryonic stem cell (hESC) identity, suggests broader functional implications.

Purpose of the Study:

• To systematically identify transposable elements (TEs) significantly associated with the tissue-specific expression of long non-coding RNAs (lncRNAs).
• To investigate the extent to which different TE families are repurposed as functional components or regulatory elements within lncRNAs.
• To explore whether TEs influence the tissue-specific expression patterns of lncRNAs.

Main Methods:

• Downloaded lncRNA expression data from the Expression Atlas for normal human tissues.
• Quantified tissue specificity of lncRNA expression.
• Employed Fisher's exact tests to assess the relationship between the presence of TE-derived sequences and tissue-specific lncRNA expression.

Main Results:

• Identified numerous significant associations between specific TE families and tissue-specific lncRNA expression.
• Demonstrated that multiple TE families can function as regulatory sequences or functional domains within lncRNAs.
• Discovered that the antisense promoter of L1PA2 (a LINE-1 subfamily) can drive placenta-specific lncRNA expression.

Conclusions:

• Transposable elements are widely repurposed as functional and regulatory elements in lncRNAs.
• TEs play a significant role in determining the tissue-specific expression profiles of lncRNAs.
• Specific TEs, like L1PA2, can act as promoters for tissue-specific lncRNA expression, highlighting their functional importance in development and tissue identity.