The XIST gene is implicated in X chromosome inactivation, yet the RNA contains no apparent open reading frame. An accumulation of XIST RNA is observed near its site of transcription, the inactive X chromosome (Xi). A series of molecular cytogenetic studies comparing properties of XIST RNA to other protein coding RNAs, support a critical distinction for XIST RNA; XIST does not concentrate at Xi simply because it is transcribed and processed there. Most notably, morphometric and 3-D analysis reveals that XIST RNA and Xi are coincident in 2- and 3-D space; hence, the XIST RNA essentially paints Xi. Several results indicate that the XIST RNA accumulation has two components, a minor one associated with transcription and processing, and a spliced major component, which stably associates with Xi. Upon transcriptional inhibition the major spliced component remains in the nucleus and often encircles the extra-prominent heterochromatic Barr body. The continually transcribed XIST gene and its polyadenylated RNA consistently localize to a nuclear region devoid of splicing factor/poly A RNA rich domains. XIST RNA remains with the nuclear matrix fraction after removal of chromosomal DNA. XIST RNA is released from its association with Xi during mitosis, but shows a unique highly particulate distribution. Collective results indicate that XIST RNA may be an architectural element of the interphase chromosome territory, possibly a component of nonchromatin nuclear structure that specifically associates with Xi. XIST RNA is a novel nuclear RNA which potentially provides a specific precedent for RNA involvement in nuclear structure and cis-limited gene regulation via higher-order chromatin packaging.
Article|
February 01 1996
XIST RNA paints the inactive X chromosome at interphase: evidence for a novel RNA involved in nuclear/chromosome structure.
In Special Collection:
JCB65: RNA
C M Clemson,
C M Clemson
Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA.
Search for other works by this author on:
J A McNeil,
J A McNeil
Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA.
Search for other works by this author on:
H F Willard,
H F Willard
Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA.
Search for other works by this author on:
J B Lawrence
J B Lawrence
Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA.
Search for other works by this author on:
C M Clemson
Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA.
J A McNeil
Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA.
H F Willard
Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA.
J B Lawrence
Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA.
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1996) 132 (3): 259–275.
Citation
C M Clemson, J A McNeil, H F Willard, J B Lawrence; XIST RNA paints the inactive X chromosome at interphase: evidence for a novel RNA involved in nuclear/chromosome structure.. J Cell Biol 1 February 1996; 132 (3): 259–275. doi: https://doi.org/10.1083/jcb.132.3.259
Download citation file: