Accepted_test

Non-B DNA Structures Adjacent to Ultraconserved Non-Coding Elements Unveiled

by Irina Makarova | Dmitry Kaluzhny | Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia | Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia

Abstract ID: 702

Event: BGRS-abstracts

Sections: [Sym 1] Section “Structural-functional organization of genomes and transcriptomics”

Non-coding, yet highly conserved genomic elements persist virtually unchanged from chickens and other evolutionarily distant vertebrates to humans. The reasons for such evolutionary stability are explored mainly in terms of their nucleotide composition. Our aim is to expand the analysis and determine the potential role of adjacent regions in the evolutionary conservation of these elements.

We analyzed ultraconserved non-coding elements (UCNEs) in three organisms - human, mouse and zebrafish. In all three genomes, we observed enrichment of guanine and cytosine in regions adjacent to UCNEs. The observed unevenness in nucleotide composition prompted us to examine non-B DNA structures that are specific to the genomic sequence and could form within or in close proximity to UCNEs.

We found significant enrichment of quadruplexes and H-DNA motifs in regions adjacent to ultraconserved elements. We also noted, that quadruplexes exhibit enrichment asymmetry from 3' end of UCNEs. Interestingly, different ultraconserved elements were flanked by quadruplexes and H-motifs.

We conducted, for the first time, an analysis of the association between UCNEs and non-B DNA structures. Our study opens up perspectives for investigating the functional significance of ultraconserved non-coding elements.