A new paper in Nature Genetics challenges the current model of how the genome’s 3D organisation controls gene expression. Using Drosophila fruit flies that carry rearranged chromosomes, researchers found that major changes in the genome organisation had surprisingly little effect on gene expression.
In my drawing the pyramids represent normal chromosomes, while the reflection in the water below shows rearranged chromosomes – even though the structures of the pyramids are altered, the overall nature of the gene expression landscape is unaffected. This exciting finding suggests that there must be additional unknown mechanisms that control interactions between regulatory elements and their target genes, raising many interesting questions for future research.
Congratulations to the Furlong and Korbel groups at EMBL and many thanks to Tabea Rauscher and Eileen Furlong for this fantastic collaboration!
My thought process behind this illustration:
This drawing is based on real Hi-C data, which often creates triangular patterns that resemble pyramids (some real Hi-C data is shown in the reflection near the base of the pyramids). Hi-C measures how often certain DNA stretches interact with each other in 3D, and the colors indicate the frequency of their interactions. Domains with frequent interactions form triangles that are often clearly separated from each other – this is illustrated by the pyramids and the rocks between them. The major conclusion of the paper is that even though the domain structure is rearranged the expression levels of most genes are not affected. Similarly, even though the pyramids in the reflection is altered, the overall nature of the landscape is unaffected.