共查询到20条相似文献,搜索用时 593 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
9.
Targeted mutagenesis of Tsix leads to nonrandom X inactivation. 总被引:10,自引:0,他引:10
During X inactivation, mammalian female cells make the selection of one active and one inactive X chromosome. X chromosome choice occurs randomly and results in Xist upregulation on the inactive X. We have hypothesized that the antisense gene, Tsix, controls Xist expression. Here, we create a targeted deletion of Tsix in female and male mouse cells. Despite a deficiency of Tsix RNA, X chromosome counting remains intact: female cells still inactivate one X, while male cells block X inactivation. However, heterozygous female cells show skewed Xist expression and primary nonrandom inactivation of the mutant X. The ability of the mutant X to block Xist accumulation is compromised. We conclude that Tsix regulates Xist in cis and determines X chromosome choice without affecting silencing. Therefore, counting, choice, and silencing are genetically separable. Contrasting effects in XX and XY cells argue that negative and positive factors are involved in choosing active and inactive Xs. 相似文献
10.
Tsix silences Xist through modification of chromatin structure 总被引:5,自引:0,他引:5
11.
12.
13.
14.
15.
16.
17.
18.
A new study shows that expression of Tsix, an antisense Xist gene, can be controlled by imprinting, and that high Tsix activity during X inactivation can protect the future active X chromosome from silencing by Xist. Tsix and Xist seem to have a yin and yang relationship, with opposite effects on X inactivation. 相似文献
19.
20.
Regulation of imprinted X-chromosome inactivation in mice by Tsix 总被引:11,自引:0,他引:11