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

IMPRINTED X-INACTIVATION MAINTAINED BY A MOUSE POLYCOMB GROUP GENE

Jesse Mager
University of North Carolina - Chapel Hill
Magnuson Lab
102 Mason Farm Rd. rm 11-116
Chapel Hill 27599 USA

Co-Authors: Jainbo Wang, Terry Magnuson
Institutions: University of North Carolina at Chapel HIll

In mammals, dosage compensation of X-linked genes is achieved by transcriptional silencing of one X chromosome in the female. This process, called X-inactivation, is usually random in the embryo proper. However, in marsupials and the extraembryonic region of the mouse, X-inactivation is imprinted: the paternal X chromosome is preferentially inactivated while the maternal X is always active. Having more than one active X is deleterious to extraembryonic development in mouse. Here we show that eed (embryonic ectoderm development), a member of the Polycomb-group genes, is requred for primary and secondary giant cell development in female embryos. Results from mice carrying a paternally inherited X-linked GFP transgene implicate eed in the stable maintenance of imprinted X-inactivation in extraembryonic tissues. Based on the recent finding that Eed interacts with histone deacetylases, we suggest that one component of this maintenance activity involves hypoacetylation of the inactivated paternal X in extraembryonic tissues.