Identification of Spen as a Crucial Factor for Xist Function through Forward Genetic Screening in Haploid Embryonic Stem Cells

MONFORT, Asun, Giulio DI MININ, Andreas POSTLMAYR, R. FREIMANN, Fabiana ARIETI, Stéphane THORE and Anton WUTZ. Identification of Spen as a Crucial Factor for Xist Function through Forward Genetic Screening in Haploid Embryonic Stem Cells. Cell Reports. CAMBRIDGE: Cell Press, 2015, vol. 12, No 4, p. 554-561. ISSN 2211-1247. doi:10.1016/j.celrep.2015.06.067.

Basic information

• Original name: Identification of Spen as a Crucial Factor for Xist Function through Forward Genetic Screening in Haploid Embryonic Stem Cells
• Authors: MONFORT, Asun (756 Switzerland), Giulio DI MININ (756 Switzerland), Andreas POSTLMAYR (756 Switzerland), R. FREIMANN (756 Switzerland), Fabiana ARIETI (380 Italy, guarantor, belonging to the institution), Stéphane THORE (250 France) and Anton WUTZ (756 Switzerland).
• Edition: Cell Reports, CAMBRIDGE, Cell Press, 2015, 2211-1247.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: Genetics and molecular biology
• Country of publisher: United States of America
• Confidentiality degree: is not subject to a state or trade secret
• WWW: URL
• Impact factor: Impact factor: 7.870
• RIV identification code: RIV/00216224:14740/15:00085377
• Organization unit: Central European Institute of Technology
• Doi: http://dx.doi.org/10.1016/j.celrep.2015.06.067
• UT WoS: 000358742300003
• Keywords in English: INACTIVE X-CHROMOSOME; DOSAGE COMPENSATION; SAF-A; RNA; SHARP; MICE; LOCALIZATION; MAINTENANCE; ACTIVATION; SUPPRESSOR
• Tags: OA, rivok
• Tags: International impact, Reviewed

Abstract

In mammals, the noncoding Xist RNA triggers transcriptional silencing of one of the two X chromosomes in female cells. Here, we report a genetic screen for silencing factors in X chromosome inactivation using haploid mouse embryonic stem cells (ESCs) that carry an engineered selectable reporter system. This system was able to identify several candidate factors that are genetically required for chromosomal repression by Xist. Among the list of candidates, we identify the RNA-binding protein Spen, the homolog of split ends. Independent validation through gene deletion in ESCs confirms that Spen is required for gene repression by Xist. However, Spen is not required for Xist RNA localization and the recruitment of chromatin modifications, including Polycomb protein Ezh2. The identification of Spen opens avenues for further investigation into the gene-silencing pathway of Xist and shows the usefulness of haploid ESCs for genetic screening of epigenetic pathways.