Pal, K., Forcato, M., Jost, D., Sexton, T., Vaillant, C., Salviato, E., Mazza, E.M.C., Lugli, E., Cavalli, G., Ferrari, F. (2019). Global chromatin conformation differences in the Drosophila dosage compensated chromosome X.  Nat. Commun. 10(1): 5355.

FBrf0244130

Research paper

In Drosophila melanogaster the single male chromosome X undergoes an average twofold transcriptional upregulation for balancing the transcriptional output between sexes. Previous literature hypothesised that a global change in chromosome structure may accompany this process. However, recent studies based on Hi-C failed to detect these differences. Here we show that global conformational differences are specifically present in the male chromosome X and detectable using Hi-C data on sex-sorted embryos, as well as male and female cell lines, by leveraging custom data analysis solutions. We find the male chromosome X has more mid-/long-range interactions. We also identify differences at structural domain boundaries containing BEAF-32 in conjunction with CP190 or Chromator. Weakening of these domain boundaries in male chromosome X co-localizes with the binding of the dosage compensation complex and its co-factor CLAMP, reported to enhance chromatin accessibility. Together, our data strongly indicate that chromosome X dosage compensation affects global chromosome structure.

PMC6877619 (PMC) (EuropePMC)