Imprinted X inactivation maintained by a mouse Polycomb group gene.
In mammals, dosage compensation of X-linked genes is achieved by the transcriptional silencing of one X chromosome in the female (reviewed in ref. 1). This process, called X inactivation, is usually random in the embryo proper. In marsupials and the extra-embryonic region of the mouse, however, X inactivation is imprinted: the paternal X chromosome is preferentially inactivated whereas the maternal X is always active. Having more than one active X chromosome is deleterious to extra-embryonic development in the mouse. Here we show that the gene eed (embryonic ectoderm development), a member of the mouse Polycomb group (Pc-G) of genes, is required for primary and secondary trophoblast giant cell development in female embryos. Results from mice carrying a paternally inherited X-linked green fluorescent protein (GFP) transgene implicate eed in the stable maintenance of imprinted X inactivation in extra-embryonic tissues. Based on the recent finding that the Eed protein interacts with histone deacetylases, we suggest that this maintenance activity involves hypoacetylation of the inactivated paternal X chromosome in the extra-embryonic tissues.
Wang
J
J
Department of Genetics, CB 7264, The University of North Carolina, 102 Mason Farm Road, Chapel Hill, North Carolina 27599-7264, USA.
Mager
J
J
Chen
Y
Y
Schneider
E
E
Cross
J C
JC
Nagy
A
A
Magnuson
T
T
D000107:Acetylation; D000818:Animals; D002452:Cell Count; D003433:Crosses, Genetic; D004303:Dosage Compensation, Genetic; D005260:Female; D018392:Genomic Imprinting / Q000235:genetics*; D049452:Green Fluorescent Proteins; D006655:Histone Deacetylases / Q000378:metabolism; D006720:Homozygote; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D005810:Multigene Family; D010920:Placenta / Q000166:cytology / Q000378:metabolism; D010928:Placental Lactogen / Q000096:biosynthesis; D063151:Polycomb Repressive Complex 2; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D012737:Sex Factors; D019076:Transgenes; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism*
C107275:Eed protein, mouse; D008164:Luminescent Proteins; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins; D049452:Green Fluorescent Proteins; C085699:placental lactogen I, rat; D010928:Placental Lactogen; D063151:Polycomb Repressive Complex 2; D006655:Histone Deacetylases