Dosage compensation

Dosage compensation is a process that balances expression of sex-linked and autosomal genes in the heterogametic sex. For example, one X chromosome in XX female mammals is randomly inactivated in every cell, and gene transcription levels from the X chromosome of XO or XY male Drosophila is elevated to approximately equal the output of two sex chromosomes in XX females.

Latest Research and Reviews

News and Comment

  • News & Views |

    The molecular mechanisms by which a few molecules of the long non-coding RNA Xist silence genes on the entire X chromosome are poorly understood. New evidence suggests that dimeric foci of Xist seed the formation of large protein assemblies that contain a wide spectrum of proteins, such as SPEN (SHARP), CIZ1, CELF, PTBP1 and components of Polycomb repressive complexes 1 and 2. These assemblies, each of which may contain hundreds to thousands of molecules of proteins, extend spatially beyond each focus of Xist, which explains how this long non-coding RNA triggers silencing across an entire chromosome.

    • Andrea Cerase
    • , J. Mauro Calabrese
    •  & Gian Gaetano Tartaglia
  • News & Views |

    Upregulation of the X chromosome compensates for the presence of a single active X chromosome in mammals, but this has been difficult to measure and to understand mechanistically. A study now demonstrates that increased burst frequency boosts the transcriptional output of X-linked genes in male and female cells with a single active X chromosome. Interestingly, female embryonic stem cells lack increased burst frequency, which is established only after inactivation of the X chromosome takes place; this finding reveals a switch that can modulate transcriptional bursting.

    • Xinxian Deng
    •  & Christine M. Disteche
  • Comments & Opinion |

    The long non-coding RNA Xist induces heterochromatinization of the X chromosome by recruiting repressive protein complexes to chromatin. Here we gather evidence, from the literature and from computational analyses, showing that Xist assemblies are similar in size, shape and composition to phase-separated condensates, such as paraspeckles and stress granules. Given the progressive sequestration of Xist’s binding partners during X-chromosome inactivation, we formulate the hypothesis that Xist uses phase separation to perform its function.

    • Andrea Cerase
    • , Alexandros Armaos
    •  & Gian Gaetano Tartaglia