DrosOCB: a high resolution map of conserved non coding sequences in Drosophila

TL;DR

This paper introduces a novel alignment method to create a detailed map of conserved non-coding DNA regions across multiple Drosophila species, revealing frequent small-scale rearrangements and aiding functional annotation.

Contribution

The study presents a new large-scale alignment strategy that accurately maps conserved non-coding regions despite rearrangements, expanding understanding of regulatory DNA evolution in Drosophila.

Findings

Identification of numerous small-scale rearrangements in non-coding regions

Creation of a comprehensive catalogue of conserved non-coding blocks (CNBs)

Potential for discovering unannotated functional elements

Abstract

Comparative genomics methods are widely used to aid the functional annotation of non coding DNA regions. However, aligning non coding sequences requires new algorithms and strategies, in order to take into account extensive rearrangements and turnover during evolution. Here we present a novel large scale alignment strategy which aims at drawing a precise map of conserved non coding regions between genomes, even when these regions have undergone small scale rearrangments events and a certain degree of sequence variability. We applied our alignment approach to obtain a genome-wide catalogue of conserved non coding blocks (CNBs) between Drosophila melanogaster and 11 other Drosophila species. Interestingly, we observe numerous small scale rearrangement events, such as local inversions, duplications and translocations, which are not observable in the whole genome alignments currently available. The high rate of observed low scale reshuffling show that this database of CNBs can constitute the starting point for several investigations, related to the evolution of regulatory DNA in Drosophila and the in silico identification of unannotated functional elements.