Nucleoplasmic organization of small nuclear ribonucleoproteins in cultured human cells.

摘要: The organization of eight small nuclear ribonucleoproteins (the U1, U2, U4, U5, and U6 RNAs previously studied by others three additional snRNAs, U11, U12, 7SK) has been investigated in cultured human cells fluorescence situ hybridization with antisense DNA 2'-O-Me RNA oligonucleotides. Using highly sensitive digital imaging microscopy we demonstrate that all these snRNAs are widespread throughout the nucleoplasm, but they excluded from nucleoli. In addition, U6, U12 concentrated discrete foci, known as coiled bodies, U1 7SK not. addition to a classic speckled pattern was observed nucleoplasm monolayer-grown HeLa cells, whereas suspension-grown revealed more diffuse nucleoplasmic labeling. Immunofluorescence staining using various snRNP-specific antisera shows complete agreement their snRNA oligonucleotide counterparts. Although U2 is quantitation signals probe reveals bulk snRNP located nucleoplasm. Furthermore, simultaneous visualization tandemly repeated genes demonstrates bodies not sites transcription.