Aims: Definition of sense and antisense microRNA matches in 3’utr.
Background: Matches of mature microRNAs (m-miRs) in human 3’utr could be traced to mutations
producing fragments of original m-miR sequences without physical separation. (The m-miR
matches in 5’utr and cds should be by far fewer, but could follow similar patterns).
Objective: To ascertain if the sense and antisense m-miR fragments in 3’utr occur at similar or different
Methods: Frequency of sense and antisense m-miR matches in 3'utr was examined in the range of
Results: The fragmentation occurs at gene level by mutation within one of the paired m-miRs,
which upon transcription results in increased interactive capability for both former pre-micro (premir)
RNA stem partners. The non-mutated stem partner can persist in 3’utr sequences, as is apparent
from significant presence of miR-619-5p and miR-5096 and some conservation of 20 other
simian- specific m-miR sequences. However, most of m-mir sequences in 3’utr are extensively
fragmented, with low preservation of long matches. In flanks of individual m-miR embeds the mutated
pre-mir positions are to a degree defined specifically.
Conclusion: The m-mir matches of various sizes in 3’utr apparently reflect accumulation, on a phylogenetic
time scale, of in-sequence point mutations. Across human 3’utr this fragmentation is significantly
less for evolutionarily recent human m-miRs that originate in simians compared to human
m-miRs first appearing in lower primates, and especially to human m-miRs introduced in nonprimates.