Simmler M C, Cunningham D B, Clerc P, Vermat T, Caudron B, Cruaud C, Pawlak A, Szpirer C, Weissenbach J, Claverie J M, Avner P
CNRS URA1968, Génétique Moléculaire Murine, Institut Pasteur, Paris, France.
Hum Mol Genet. 1996 Nov;5(11):1713-26. doi: 10.1093/hmg/5.11.1713.
X chromosome inactivation in both mouse and human requires the presence of a cis acting locus, the X inactivation centre. This locus is thought to be involved in the initiation and spreading of the inactivation signal in early development. In order to increase our understanding of the mouse X inactivation centre, a 94 kb region immediately distal to the Xist gene has been sequenced and analysed for the presence of transcription units and/or potential cis acting regulatory elements. We have identified a novel gene, Tsx, lying 40 kb 3' from Xist. Tsx is expressed specifically in the testis and shows no convincing homology to proteins currently in the databases. A rat homologue, also X linked, has been isolated. The mouse and rat Tsx sequences are highly divergent, suggesting that part of the X inactivation centre, including both Xist and Tsx are subject to relatively weak evolutionary constraints.
在小鼠和人类中，X染色体失活都需要一个顺式作用位点，即X染色体失活中心的存在。该位点被认为参与了早期发育中失活信号的起始和传播。为了增进我们对小鼠X染色体失活中心的理解，对紧邻Xist基因下游的一个94 kb区域进行了测序，并分析了其中转录单元和/或潜在顺式作用调控元件的存在情况。我们鉴定出了一个新基因Tsx，它位于Xist基因下游3'方向40 kb处。Tsx仅在睾丸中特异性表达，且与目前数据库中的蛋白质没有明显的同源性。已分离出一个同样位于X染色体上的大鼠同源物。小鼠和大鼠的Tsx序列差异很大，这表明X染色体失活中心的一部分，包括Xist和Tsx，受到的进化限制相对较弱。
