Open AccessEmbryonic loss of human females with partial trisomy 19 identifies region critical for the single active X
Author(s) -
Barbara R. Migeon,
M Beer,
Hans T. Björnsson
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0170403
Subject(s) - xist , x inactivation , x chromosome , biology , dosage compensation , genetics , skewed x inactivation , human genome , trisomy , genome , gene
To compensate for the sex difference in the number of X chromosomes, human females, like human males have only one active X. The other X chromosomes in cells of both sexes are silenced in utero by XIST , the Inactive X Specific Transcript gene , that is present on all X chromosomes. To investigate the means by which the human active X is protected from silencing by XIST , we updated the search for a key dosage sensitive XIST repressor using new cytogenetic data with more precise resolution. Here, based on a previously unknown sex bias in copy number variations, we identify a unique region in our genome, and propose candidate genes that lie within, as they could inactivate XIST . Unlike males, the females who duplicate this region of chromosome 19 (partial 19 trisomy) do not survive embryogenesis; this preimplantation loss of females may be one reason that more human males are born than females.