Antisense Activity across the Nesp Promoter is Required for Nespas-Mediated Silencing in the Imprinted Gnas Cluster

Non-Coding RNA

Charlotte J. Tibbit¹  Christine M. Williamson¹  Stuti Mehta¹  Simon T. Ball¹  Mita Chotalia²  Wade T. Nottingham¹  Sally A. Eaton¹  Mohamed M. Quwailid¹  Lydia Teboul³  Gavin Kelsey²  Jo Peters¹ 

[1] MRC Harwell, Mammalian Genetics Unit, Harwell Campus, Oxfordshire OX110RD, UK; E-Mails:;Epigenetics Programme, The Babraham Institute, Cambridge CB223AT, UK; E-Mails:;Mary Lyon Centre, MRC Harwell, Harwell Campus, Oxfordshire OX110RD, UK; E-Mail:

关键词: long non-coding RNA;    antisense;    genomic imprinting;    epigenetic silencing;    Nespas;    Nesp;    Gnas cluster;   

DOI  :  10.3390/ncrna1030246

来源: mdpi

【 摘 要 】

Macro long non-coding RNAs (lncRNAs) play major roles in gene silencing in inprinted gene clusters. Within the imprinted Gnas cluster, the paternally expressed Nespas lncRNA downregulates its sense counterpart Nesp. To explore the mechanism of action of Nespas, we generated two new knock-in alleles to truncate Nespas upstream and downstream of the Nesp promoter. We show that Nespas is essential for methylation of the Nesp differentially methylated region (DMR), but higher levels of Nespas are required for methylation than are needed for downregulation of Nesp. Although Nespas is transcribed for over 27 kb, only Nespas transcript/transcription across a 2.6 kb region that includes the Nesp promoter is necessary for methylation of the Nesp DMR. In both mutants, the levels of Nespas were extraordinarily high, due at least in part to increased stability, an effect not seen with other imprinted lncRNAs. However, even when levels were greatly raised, Nespas remained exclusively cis-acting. We propose Nespas regulates Nesp methylation and expression to ensure appropriate levels of expression of the protein coding transcripts Gnasxl and Gnas on the paternal chromosome. Thus, Nespas mediates paternal gene expression over the entire Gnas cluster via a single gene, Nesp.

【 授权许可】

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