In vivo detection of snRNP-rich organelles in the nuclei of mammalian cells

M. Carmo-Fonseca, R. Pepperkok, B. S. Sproat, W. Ansorge, M. S. Swanson, A. I. Lamond

Research output: Contribution to journalArticlepeer-review

114 Citations (Scopus)


The in vivo distribution of snRNPs has been analysed by microinjecting fluorochrome-labelled antisense probes into the nuclei of live HeLa and 3T3 cells. Probes for U2 and U5 snRNAs specifically label the same discrete nuclear foci while a probe for U1 snRNA shows widespread nucleoplasmic labelling, excluding nucleoli, in addition to labelling foci. A probe for U3 snRNA specifically labels nucleoli. These in vivo data confirm that mammalian cells have nuclear foci which contain spliceosomal snRNPs. Co-localization studies, both in vivo and in situ, demonstrate that the spliceosomal snRNAs are present in the same nuclear foci. These foci are also stained by antibodies which recognize snRNP proteins, m3G-cap structures and the splicing factor U2AF but are not stained by anti-SC-35 or anti-La antibodies. U1 snRNP and the splicing factor U2AF closely co-localize in the nucleus, both before and after actinomycin D treatment, suggesting that they may both be part of the same complex in vivo.

Original languageEnglish
Pages (from-to)1863-1873
Number of pages11
JournalEMBO Journal
Issue number7
Publication statusPublished - 5 Jul 1991


  • 2'-O-alkyl RNA
  • in vivo antisense labelling
  • mammalian nucleus
  • microinjection
  • snRNA


Dive into the research topics of 'In vivo detection of snRNP-rich organelles in the nuclei of mammalian cells'. Together they form a unique fingerprint.

Cite this