Lyon M F
Medical Research Council, Mammalian Genetics Unit, Didcot, Oxon, UK.
Cytogenet Cell Genet. 1998;80(1-4):133-7. doi: 10.1159/000014969.
Recent work has shown that X-chromosome inactivation is brought about by Xist mRNA, which coats the inactive X-chromosome. This paper presents a hypothesis on the function of this RNA. It is suggested that interspersed repetitive elements of the LINE type, in which the X-chromosome is particularly rich, act as booster elements to promote the spread of Xist mRNA. Contact with this RNA causes the LINE elements to be sensed as repeated elements by the cell's system for repeat-induced gene silencing. This leads to the silencing of these elements and the intervening unique sequences by their conversion to heterochromatin.
最近的研究表明，X染色体失活是由Xist mRNA引起的，Xist mRNA覆盖在失活的X染色体上。本文提出了关于这种RNA功能的假说。有人认为，X染色体中特别丰富的LINE类型的散布重复元件充当增强元件，以促进Xist mRNA的扩散。与这种RNA接触会导致LINE元件被细胞的重复序列诱导基因沉默系统识别为重复元件。这会导致这些元件以及其间的独特序列通过转化为异染色质而沉默。
