Evolution of microRNA in primates

Area of Science:

• Evolutionary biology
• Genomics
• Molecular biology

Background:

• MicroRNAs (miRNAs) are crucial for post-transcriptional gene regulation, impacting thousands of messenger RNA targets.
• Primate miRNA evolution is understudied, with most non-human primate miRNAs predicted computationally without experimental validation.
• Understanding miRNA evolution is key to comprehending phenotypic changes and human evolutionary history.

Purpose of the Study:

• To experimentally validate and characterize microRNA evolution across a wide range of primate species.
• To identify conserved and divergent miRNA sequences and structures throughout primate phylogeny.
• To investigate the role of novel or altered miRNAs in primate evolutionary adaptations, especially in neuronal processes.

Main Methods:

• Sequencing of thirteen diverse primate species representing various phylogenetic positions.
• Experimental validation of hundreds of microRNAs (miRNAs).
• Comparative genomic analysis of miRNA sequences and pre-miRNA hairpin structures.

Main Results:

• Hundreds of microRNAs (miRNAs) were experimentally validated, tripling the number of species with validated miRNAs.
• High conservation of miRNA seed regions and mature sequences was observed across primates, alongside conserved pre-miRNA hairpin structures.
• Notable exceptions included structural changes in miR-501 leading to seed shifts and an expansion of miR-320 paralogs, with many non-conserved miRNAs potentially regulating neuronal processes.

Conclusions:

• MicroRNA evolution in primates shows both high conservation and significant divergence, offering insights into regulatory plasticity.
• The identification of novel and altered miRNAs, particularly those affecting neuronal pathways, highlights their importance in primate evolution.
• This study significantly expands the experimentally validated repertoire of primate miRNAs and provides a foundation for future research into miRNA function and evolution.