Manipulation of Xist Imprinting in Mouse Preimplantation Embryos
X-chromosome inactivation (XCI) is established in preimplantation embryos in mice. Prior to the establishment of XCI, expression of the long noncoding RNA (lncRNA) Xist is essential. Xist expression in mouse preimplantation embryos is imprinted, and paternal Xist is predominantly expressed. Due to the manner of imprinting, maternal Xist is always silenced. However, the nature of imprinting to repress maternal Xist is variable. For example, parthenogenetic embryos that are composed of two maternal genomes exhibit maternal Xist derepression during the preimplantation phases. Maintenance of Xist imprinting to repress maternal Xist depends on the chromatin condensation states and the dosage of Rnf12, an essential Xist activator. Therefore, alterations of chromatin states and Rnf12 expression levels lead to maternal Xist derepression. In this chapter, we describe the method for derepressing maternal Xist by various approaches, such as mRNA injection, small molecule treatment, and nuclear transfer.
Key wordsImprinted XCI Maternal Xist Chromatin condensation
This work was supported by JSPS postdoctoral fellowships for research abroad to A.F. JSPS KAKENHI Grant-in-Aid for Young Scientists (26861350) to A.F.
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