TY - JOUR
T1 - Genes flanking Xist in mouse and human are separated on the X chromosome in American marsupials
AU - Shevchenko, Alexander I.
AU - Zakharova, Irina S.
AU - Elisaphenko, Eugeny A.
AU - Kolesnikov, Nicolay N.
AU - Whitehead, Siobhan
AU - Bird, Christine
AU - Ross, Mark
AU - Weidman, Jennifer R.
AU - Jirtle, Randy L.
AU - Karamysheva, Tatiana V.
AU - Rubtsov, Nicolay B.
AU - VandeBerg, John L.
AU - Mazurok, Nina A.
AU - Nesterova, Tatyana B.
AU - Brockdorff, Neil
AU - Zakian, Suren M.
N1 - Funding Information:
This work was supported by funding from the Wellcome Trust, UK (an International Development Award, 067065/Z/02/Z, for A.I.S.), from the Russian Foundation for Fundamental Research (grants 06-04-48337 and 05-04-48230a) and the Russian Academy of Science Foundation Program for Molecular and Cell Biology. We also thank the Sequencing Division at the Wellcome Trust Sanger Institute.
PY - 2007/2
Y1 - 2007/2
N2 - X inactivation, the transcriptional silencing of one of the two X chromosomes in female mammals, achieves dosage compensation of X-linked genes relative to XY males. In eutherian mammals X inactivation is regulated by the X-inactive specific transcript (Xist), a cis-acting non-coding RNA that triggers silencing of the chromosome from which it is transcribed. Marsupial mammals also undergo X inactivation but the mechanism is relatively poorly understood. We set out to analyse the X chromosome in Monodelphis domestica and Didelphis virginiana, focusing on characterizing the interval defined by the Chic1 and Slc16a2 genes that in eutherians flank the Xist locus. The synteny of this region is retained on chicken chromosome 4 where other loci belonging to the evolutionarily ancient stratum of the human X chromosome, the so-called X conserved region (XCR), are also located. We show that in both M. domestica and D. virginiana an evolutionary breakpoint has separated the Chic1 and Slc16a2 loci. Detailed analysis of opossum genomic sequences revealed linkage of Chic1 with the Lnx3 gene, recently proposed to be the evolutionary precursor of Xist, and Fip1, the evolutionary precursor of Tsx, a gene located immediately downstream of Xist in eutherians. We discuss these findings in relation to the evolution of Xist and X inactivation in mammals.
AB - X inactivation, the transcriptional silencing of one of the two X chromosomes in female mammals, achieves dosage compensation of X-linked genes relative to XY males. In eutherian mammals X inactivation is regulated by the X-inactive specific transcript (Xist), a cis-acting non-coding RNA that triggers silencing of the chromosome from which it is transcribed. Marsupial mammals also undergo X inactivation but the mechanism is relatively poorly understood. We set out to analyse the X chromosome in Monodelphis domestica and Didelphis virginiana, focusing on characterizing the interval defined by the Chic1 and Slc16a2 genes that in eutherians flank the Xist locus. The synteny of this region is retained on chicken chromosome 4 where other loci belonging to the evolutionarily ancient stratum of the human X chromosome, the so-called X conserved region (XCR), are also located. We show that in both M. domestica and D. virginiana an evolutionary breakpoint has separated the Chic1 and Slc16a2 loci. Detailed analysis of opossum genomic sequences revealed linkage of Chic1 with the Lnx3 gene, recently proposed to be the evolutionary precursor of Xist, and Fip1, the evolutionary precursor of Tsx, a gene located immediately downstream of Xist in eutherians. We discuss these findings in relation to the evolution of Xist and X inactivation in mammals.
KW - Didelphis virginiana
KW - Marsupial
KW - Monodelphis domestica
KW - Opossum
KW - X chromosome
KW - X inactivation
KW - Xist
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U2 - 10.1007/s10577-006-1115-9
DO - 10.1007/s10577-006-1115-9
M3 - Article
C2 - 17333537
AN - SCOPUS:33847631186
VL - 15
SP - 127
EP - 136
JO - Chromosome Research
JF - Chromosome Research
SN - 0967-3849
IS - 2
ER -