Functional Implications of RNA Splicing for Human Long Intergenic Noncoding RNAs.

Area of Science:

• Genomics
• Molecular Biology
• Evolutionary Biology

Background:

• Long intergenic noncoding RNAs (lincRNAs) are implicated in human gene regulation.
• Most human lincRNAs are multi-exonic and undergo alternative splicing (AS).
• The link between AS and lincRNA function remains unclear.

Purpose of the Study:

• To compare sequence evolution and biological characteristics of single-exonic lincRNAs (SELs) and multi-exonic lincRNAs (MELs).
• To investigate evolutionary differences between hominoid-specific and primate-conserved lincRNAs.
• To explore the role of alternative splicing (AS) in lincRNA functionality.

Main Methods:

• Comparative analysis of sequence evolution for SELs and MELs (including alternatively spliced exons [ASEs] and constitutively spliced exons [CSEs]).
• Assessment of exon and transcript lengths, genomic proximity to coding genes, and tissue-specific expression patterns.
• Distinction between hominoid-specific and primate-conserved lincRNAs.

Main Results:

• SELs and MELs exhibit significant biological and evolutionary differences.
• MELs (both ASEs and CSEs) evolved faster in hominoid-specific lincRNAs, while SELs evolved at a neutral rate.
• In primate-conserved lincRNAs, SELs and ASEs evolved slower than CSEs.
• SELs have longer exons and transcripts, are located closer to coding genes, and show broader tissue expression than MELs.
• Evolutionary divergence observed in hominid-specific lincRNAs compared to ancestral counterparts.

Conclusions:

• SELs and MELs represent distinct gene groups with differing evolutionary trajectories.
• Alternative splicing (AS) may play a significant role in the functionality and regulation of primate lincRNAs.
• The distinct features of SELs and MELs highlight their unique biological roles.