Selective promotion of oligonucleotides in the course of evolution

DNA is essentially a collection of short nucleotide sequences with a myriad of functionalities. These oligonucleotides are often studied for their function as molecular binding sites, regulatory motifs or sequence probes. The field of Bioinformatics uses a similar concept under the term “ k -mers,” which is central to various tasks, like comparing the similarity of different DNA sequences in phylogenetic tree reconstruction. The present study explores if k- mers experience selection pressure in the course of evolution. Our meta-analysis, spanning multiple organisms, suggests positive selection of genetic changes, where the associated k-mers are more redundant in the genome, relative to their wild-type counterparts.