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Human Genetics

, Volume 103, Issue 1, pp 29–33 | Cite as

Histone H4 acetylation analyses in patients with polysomy X: implications for the mechanism of X inactivation

  • C. A. Leal
  • M. L. Ayala-Madrigal
  • L. E. Figuera
  • C. Medina
Original investigation

Abstract

In humans, it is thought that the X-inactivation phenomenon occurs no matter how many X chromosomes are present, and that only one of them remains active. Nevertheless, individuals who have an abnormal number of X chromosomes show a wide spectrum of abnormalities, which increase with the number of X chromosomes present in a given individual. It has been shown that the inactive X chromosome in female mammals is distinguished by a lack of histone H4 acetylation, and that this could be used as an accessible marker for distinguishing between Xi and Xa in spreads of metaphase chromosomes. We studied three X-polysomic patients for the presence of active chromatin by analysis of histone H4 acetylation on unfixed metaphase spreads. Using antisera to H4 acetylated at lysines 16, 8 and 5, respectively, we observed frequencies different from those expected from cells with only one underacetylated X chromosome. In particular, when antiserum to H4 acetylated at lysine 16 was used about 90% of the cells showed acetylation of all X chromosomes. This suggests a possible disturbance in the deacetylation process, probably due to the presence of multiple Xs.

Keywords

Lysine Wide Spectrum Metaphase Chromosome Metaphase Spread Active Chromatin 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • C. A. Leal
    • 1
  • M. L. Ayala-Madrigal
    • 1
  • L. E. Figuera
    • 1
  • C. Medina
    • 1
  1. 1.División de Genética, Centro de Investigación Biomédica de Occidente, IMSS, Sierra Mojada 800, Col. Independencia, c.p. 44340, Apartado Postal 1-3838 Guadalajara, Jalisco, México

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