title: Comparative sequence analysis of the X-inactivation center region in mouse, human, and bovine.
abstract: We have sequenced to high levels of accuracy 714-kb and 233-kb regions of the mouse and bovine X-inactivation centers (Xic), respectively, centered on the Xist gene. This has provided the basis for a fully annotated comparative analysis of the mouse Xic with the 2.3-Mb orthologous region in human and has allowed a three-way species comparison of the core central region, including the Xist gene. These comparisons have revealed conserved genes, both coding and noncoding, conserved CpG islands and, more surprisingly, conserved pseudogenes. The distribution of repeated elements, especially LINE repeats, in the mouse Xic region when compared to the rest of the genome does not support the hypothesis of a role for these repeat elements in the spreading of X inactivation. Interestingly, an asymmetric distribution of LINE elements on the two DNA strands was observed in the three species, not only within introns but also in intergenic regions. This feature is suggestive of important transcriptional activity within these intergenic regions. In silico prediction followed by experimental analysis has allowed four new genes, Cnbp2, Ftx, Jpx, and Ppnx, to be identified and novel, widespread, complex, and apparently noncoding transcriptional activity to be characterized in a region 5' of Xist that was recently shown to attract histone modification early after the onset of X inactivation.
authors.affiliation: Unité de Génétique Moléculaire Murine, URA CNRS 1947, Institut Pasteur, Paris, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Chureau
authors.forename: Marine
authors.initials: M
authors.lastname: Prissette
authors.forename: Agnès
authors.initials: A
authors.lastname: Bourdet
authors.forename: Valérie
authors.initials: V
authors.lastname: Barbe
authors.forename: Laurence
authors.initials: L
authors.lastname: Cattolico
authors.forename: Louis
authors.initials: L
authors.lastname: Jones
authors.forename: André
authors.initials: A
authors.lastname: Eggen
authors.forename: Philip
authors.initials: P
authors.lastname: Avner
authors.forename: Laurent
authors.initials: L
authors.lastname: Duret
mesh_terms: D000818:Animals; D002417:Cattle; D017124:Conserved Sequence / Q000235:genetics; D004303:Dosage Compensation, Genetic; D019143:Evolution, Molecular; D005260:Female; D005796:Genes / Q000235:genetics; D005807:Genes, Overlapping / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D011544:Pseudogenes / Q000235:genetics; D018626:Retroelements / Q000235:genetics; D017422:Sequence Analysis, DNA / Q000379:methods*; D014960:X Chromosome / Q000235:genetics*
chemical_list: D005819:Genetic Markers; D018626:Retroelements