International Mammalian Genome Society

The 16th International Mouse Genome Conference (2002)

Plenary Presentations * Oral Presentations *
Poster Presentations: Complex Genetics and Disease Modifiers * Developmental Genetics * Functional Genomics * Gene Discovery * Genetic Manipulations to Alter Gene Function * Mouse Models: Human Disease and Pharmacogenetics * Sequence Annotation and Comparative Analysis of Genomes *
Attendees * Sponsors * Table of Contents * Photographs * Awards

Oral Presentation

Tuesday 19 November

09:30 - 09:45 HRS

DNA METHYLATION AND CTCF BINDING SITES AT THE CPG ISLAND OF SMCX: ROLE IN DEVELOPMENTAL ESCAPE FROM X INACTIVATION

C Disteche
University of Washington

Co-Authors: 2) Filippova G, 1) Truong J-P, 3) Tsuchiya K
Institutions: 1) University of Washington, 2) Fred Hutchinson Cancer Research Center, 3) Vanderbilt University

We have previously shown that Smcx, a gene that escapes X inactivation in adult mice, can be completely inactivated in cells of early mouse embryos.  This suggests that escape from X inactivation is preceded by inactivation, followed by reactivation during mouse development.  We found that Smcx CpG island is located near a gene subject to X inactivation in mouse and thus explored the possibility that chromatin boundary elements might be located in the region that separated the genes on the X chromosome.  Analysis of the CpG island of Smcx showed that at least two CTCF binding sites were located in the region, suggesting that these sites might provide an insulator function to protect Smcx from stable X inactivation.  DNA methylation at Smcx CpG island was found to change during development, with some methylation in female mouse embryos and virtually no methylation present in adult tissues.  Interestingly, DNA methylation was virtually absent from the CTCF binding sites, even in early embryos, suggesting that CTCF may regulate the establishment of methylation patterns and protect Smcx from stable silencing.