Fragmentation and Matching of Human MicroRNA Sequences in 3'utr

Area of Science:

• Genomics
• Molecular Biology
• Bioinformatics

Background:

• Mature microRNAs (m-miRs) can match in human 3' UTRs through mutations, generating fragments without physical separation.
• These fragments may arise from altered pre-microRNA (premir) stem structures due to mutations.

Purpose of the Study:

• To determine if sense and antisense m-miR fragments in 3' UTRs occur at similar or different frequencies.
• To analyze the size distribution of these fragmented m-miR sequences.

Main Methods:

• Examined the frequency of sense and antisense m-miR matches in 3' UTRs within a 7–22 nucleotide range.
• Analyzed fragmentation patterns and conservation of m-miR sequences.

Main Results:

• Fragmentation occurs at the gene level due to mutations in paired m-miRs, increasing interactive capabilities.
• Specific m-miRs like miR-619-5p and miR-5096 persist, alongside conserved simian-specific sequences, but most are fragmented.
• Fragmentation levels correlate with evolutionary history, with less fragmentation in recent human m-miRs.

Conclusions:

• Accumulation of point mutations on a phylogenetic timescale leads to fragmented m-miR matches in 3' UTRs.
• Evolutionary origin significantly impacts m-miR fragmentation in human 3' UTRs, with primate-derived m-miRs showing less fragmentation than non-primate ones.