Preprint precisely maps breakage hotspots of dicentric ring chromosomes in Drosophila

A preprint deposited on bioRxiv presents detailed mapping of the sites at which dicentric ring chromosomes preferentially break during cell division in Drosophila. Dicentric chromosomes — chromosomes with two centromeres — are pulled in opposite directions during segregation and must break, but where exactly they break has not been comprehensively characterised.

The authors precisely mapped breakage hotspots and identified three principal findings. First, duplications arising from the breaks are structurally complex, involving multiple rearrangements rather than simple end-joining, indicating that healing of dicentric breaks is a multistep process. Second, the researchers characterised the genomic features that determine hotspot locations. Third, the work advances understanding of how eukaryotic cells respond to and resolve these chromosome instability events.

Dicentric chromosomes are relevant to cancer biology — they arise in tumour cells and are a source of genomic instability — and to fundamental chromosome biology. The Drosophila system allows precise genetic control over the introduction and resolution of dicentrics.

This is a preprint and has not yet been peer-reviewed. The work is primarily of interest to researchers in chromosome biology, genome instability, and evolutionary genetics using Drosophila as a model organism.