Evolution of the human-specific microRNA miR-941

Area of Science:

• Evolutionary biology
• Genetics
• Molecular biology

Background:

• MicroRNA-mediated gene regulation is crucial for physiological processes.
• Understanding microRNA evolution provides insights into species-specific adaptations.

Purpose of the Study:

• To investigate the evolutionary origins and functions of microRNA 941 (miR-941) in humans.
• To explore miR-941's role in human evolution, cellular differentiation, and neurological functions.

Main Methods:

• Phylogenetic analysis to determine miR-941's emergence and evolutionary timeline.
• Copy-number variation analysis and correlation with human migration patterns.
• Gene expression analysis in pluripotent and differentiated cells.
• Target gene prediction and pathway analysis (hedgehog, insulin, neurotransmitter signaling).

Main Results:

• miR-941 emerged de novo in the human lineage 6-1 million years ago from a tandem repeat sequence.
• miR-941 copy-number is polymorphic in humans, decreasing with migration out of Africa.
• Emergence of miR-941 was associated with accelerated loss of its binding sites.
• miR-941 is highly expressed in pluripotent cells, repressed upon differentiation, targeting key signaling pathways.
• Human-specific miR-941 regulation affects brain genes involved in neurotransmitter signaling.

Conclusions:

• miR-941 played a significant role in human evolution, demonstrating rapid regulatory evolution.
• Its functions in cellular differentiation and neural signaling highlight its importance in human-specific traits.