Related Experiment Video
Updated: Aug 19, 2026

A Non-random Mouse Model for Pharmacological Reactivation of Mecp2 on the Inactive X Chromosome
Published on: May 22, 2019
An inactive X specific replication origin associated with a matrix attachment region in the human X linked HPRT gene
1Molecular Genetics Unit, Department of Cell and Molecular Biology, University of Technology, Sydney, NSW 2065, Australia. Koina@rsbs.anu.edu.au
Abstract:
Early in female mammalian embryogenesis, one of the two X chromosomes is inactivated to compensate the gene dosage between males and females. One of the features of X chromosome inactivation (XCI) is the late replication of the inactivated X chromosome. This study reports the identification, by competitive PCR of nascent DNA, of a replication origin in intron 2 of the human X-linked HPRT gene, that is functional only on the inactive X. Features frequently associated with replication origins, including a peak of enhanced DNA flexibility, a perfect match to the yeast ACS sequence, a 14/15 match to the Drosophila topoisomerase II consensus, and a 20/21 match to an initiation region consensus sequence, were identified close to the replication origin. The origin is located approximately 2 kb upstream of a matrix attachment region (MAR) and also contains two A:T-rich elements, thought to facilitate DNA unwinding.
More Related Videos
Related Concept Videos
Inheritance of Chromatin Structures
Heterochromatin
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Heterochromatin
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
X-Inactivation
X-inactivation
Euchromatin
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...

