Standard Article

Initiation of X-chromosome inactivation

Part 1. Genetics

1.3. Epigenetics

Short Specialist Review

  1. Lygia V. Pereira,
  2. Raquel Stabellini

Published Online: 15 JUL 2005

DOI: 10.1002/047001153X.g103316

Encyclopedia of Genetics, Genomics, Proteomics and Bioinformatics

Encyclopedia of Genetics, Genomics, Proteomics and Bioinformatics

How to Cite

Pereira, L. V. and Stabellini, R. 2005. Initiation of X-chromosome inactivation. Encyclopedia of Genetics, Genomics, Proteomics and Bioinformatics. 1:1.3:41.

Author Information

  1. Universidade de São Paulo, São Paulo, Brazil

Publication History

  1. Published Online: 15 JUL 2005

Abstract

Dosage compensation is the process by which the amount of X-linked gene products between individuals with one and two X chromosomes is equalized. In mammals, dosage compensation is achieved by the transcriptional silencing of one X chromosome in female cells. Inactivation is attained by the establishment of several sequential epigenetic modifications in the future inactive X triggered by expression of the Xist gene in cis, and including different histone modifications and methylation of CpG islands. These transformations occur during early embryonic development and require that the cell counts the X chromosomes and chooses one to be active per diploid genome, inactivating the others. Here, we will review what is currently known about the early events of X-chromosome inactivation, and discuss the mechanisms by which a cell counts and chooses X chromosomes.

Keywords:

  • X-chromosome inactivation;
  • epigenetic modifications;
  • initiation;
  • X-inactivation center;
  • Xist