Characterization of expression at the human XIST locus in somatic, embryonal carcinoma, and transgenic cell lines
Characterization of expression at the human XIST locus in somatic, embryonal carcinoma, and transgenic cell lines
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DOI：
10.1016/s0888-7543(03)00170-8
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发表时间：
2003-09-01
期刊：
影响因子：
4.4
通讯作者：
Brown, CJ
中科院分区：
文献类型：
--
作者：
Chow, JC;Hall, LL;Brown, CJ
X的失活需要XIST，这是一种功能性RNA，在雌性体细胞中只从失活的X表达，并定位于失活的X。在小鼠中，Xist的低水平不稳定转录在失活之前被观察到，反义转录物Tsix是早期Xist表达的关键调节因子。为了研究人类中反义转录的存在和影响，我们对人类体细胞癌、转基因癌和胚胎癌（EC）细胞系中正义和反义转录的程度进行了表征。在体细胞中未检测到人类XIST位点下游的反义表达，但在EC系N-Tera2D1和具有异位XIST位点的体细胞中检测到。反义的存在不会破坏义转录本的稳定性或定位。我们还在EC和雌性体细胞中发现了额外的意义转录本，并证明在体细胞杂交中，5'侧的JPX/ENOX基因在活性和非活性X染色体上都有表达，从而确定了体细胞中非活性X特异性转录控制的程度。这些分析揭示了与小鼠Xist和Tsix转录本的异同，并生成了该区域发育调节转录的复杂图景。(C) 2003 Elsevier Inc.版权所有。
X inactivation requires XIST, a functional RNA that is expressed exclusively from, and localizes to, the inactive X in female somatic cells. In mouse, low-level unstable transcription of Xist is observed prior to the time of inactivation, and an antisense transcript, Tsix, is a critical regulator of early Xist expression. To examine the presence and impact of an antisense transcript in humans we have characterized the extent of sense and antisense transcription in human somatic, transgenic, and embryonal carcinoma (EC) cell lines. Downstream antisense expression at the human XIST locus was not detected in somatic cells, but was detected in the EC line N-Tera2D1 and in somatic cells with an ectopic XIST locus. Presence of the antisense did not disrupt the stability or localization of the sense transcript. We have also identified additional sense transcripts in EC and female somatic cells and demonstrate that the 5' flanking JPX/ENOX gene is expressed from both the active and the inactive X chromosome in somatic cell hybrids, delimiting the extent of inactive X-specific transcriptional control in somatic cells. These analyses reveal similarities to and differences from the murine Xist and Tsix transcripts and generate a complex picture of developmentally regulated transcription through the region. (C) 2003 Elsevier Inc. All rights reserved.