title: X-inactivation is stably maintained in mouse embryos deficient for histone methyl transferase G9a.
abstract: One of the two X chromosomes becomes inactivated during early development of female mammals. Recent studies demonstrate that the inactive X chromosome is rich in histone H3 methylated at Lys-9 and Lys-27, suggesting an important role for these modifications in X-inactivation. It has been shown that in the mouse Eed is required for maintenance of X-inactivation in the extraembryonic lineages. Interestingly, Eed associates with Ezh2 to form a complex possessing histone methyltransferase activity predominantly for H3 Lys-27. We previously showed that G9a is one of the histone methyltransferases specific for H3 Lys-9 and is essential for embryonic development. Here we examined X-inactivation in mouse embryos deficient for G9a. Expression of Xist, which is crucial for the initiation of X-inactivation, was properly regulated and the inactivated X chromosome was stably maintained even in the absence of G9a. These results demonstrate that G9a is not essential for X-inactivation.
authors.affiliation: PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ohhata
authors.forename: Makoto
authors.initials: M
authors.lastname: Tachibana
authors.forename: Masako
authors.initials: M
authors.lastname: Tada
authors.forename: Takashi
authors.initials: T
authors.lastname: Tada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sasaki
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Shinkai
authors.forename: Takashi
authors.initials: T
authors.lastname: Sado
mesh_terms: D000818:Animals; D003433:Crosses, Genetic; D004303:Dosage Compensation, Genetic; D004622:Embryo, Mammalian / Q000201:enzymology*; D005260:Female; D018390:Gene Targeting; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000502:physiology; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000172:deficiency* / Q000235:genetics; D006720:Homozygote; D006801:Humans; D008297:Male; D008745:Methylation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D011496:Protein Methyltransferases; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000378:metabolism; D014960:X Chromosome / Q000378:metabolism*
chemical_list: D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; C077885:XIST non-coding RNA; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D000076983:Histone Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase