International Mammalian Genome Society

The 15th International Mouse Genome Conference (2001)

Table of Contents * Complex Genetics * Developmental Genetics * Gene Annotation * Gene Discovery * Genome Sequencing * Functional Genomics * Mutagenesis * Presentations * Verne Chapman Memorial Lecture

Dr Christine Disteche
University of Washington
BOX 357470
Department of Pathology
Seattle WA 98195
USA

Co-Authors:  1)Thomas S, 1)Truong J-P, 2)Tsuchiya K
Institutions:   1)Department of Pathology, University of Washington, 2)Department of Pathology, Vanderbilt University 

Developmental epigenetic changes at the CPG island of the mouse SMCX gene in relation to escape from X inactivation

Smcx is a mouse gene that escapes X inactivation in adult mice.  Our previous studies have shown that Smcx can be completely inactivated in cells of early mouse embryos.  This developmental change in the regulation of Smcx on the inactive X chromosome suggests that genes that escape X inactivation may undergo a process of reactivation during development.  In the present study we examined the methylation patterns of Smcx CpG island in mouse embryos and adult tissues.  The methylation status of CpG dinucleotides within the CpG island of the Smcx gene sequence was determined using the bisulfite method.  No methylation of the CpG island was found in adult tissues, as expected for a gene that escapes X inactivation.  In contrast, our results indicate that a specific region of the CpG island of Smcx is methylated in mouse embryos.  This cluster of methylated sites may be involved in the regulation of expression of the gene on the inactive X chromosome.  Our analysis is consistent with progressive loss of DNA methylation associated with establishment of the inactivation escape in adult mice.