Immunoelectron microscope localization of snRNPs in the polytene nucleus of salivary glands of Chironomus thummi


Por: Vazquez-Nin G.H., Echeverria O.M., Fakan S., Leser G., Martin T.E.

Publicada: 1 ene 1990
Resumen:
The ultrastructural distribution of small nuclear ribonucleoproteins (U1-snRNP and Sm antigen) in the nucleus of Chironomus salivary gland cells was investigated by means of specific antibodies and immunocytochemistry using colloidal gold complexes as markers. Particular attention was paid to the structural relationships of snRNPs with transcriptionally active areas in polytene chromosomes and with Balbiani ring granules. Our results demonstrate strong binding of anti-snRNP antibodies to RNP fibrils or the fibrillar network occurring within nuclear regions active in transcription (Balbiani rings or minor puffs). This confirms data reported previously on mammalian cells showing early association of snRNPs with nuclear fibrillar constituents containing newly synthesized pre-mRNA. In addition, Balbiani ring granules in the process of formation at the transcriptionally active sites were sometimes labeled on their periphery or on the transitory part between the granule and its precursor RNP fibril, while free granules observed in the nucleoplasm were virtually devoid of label. These findings suggest that mRNA processing, including splicing, takes place prior to the formation of mature Balbiani ring granules. © 1990 Springer-Verlag.

Filiaciones:
Vazquez-Nin G.H.:
 Centre of Electron Microscopy, University of Lausanne, 27 Bugnon, Lausanne, CH-1005, Switzerland

 Laboratory of Electron Microscopy, Department of Biology, Faculty of Sciences, National Autonomous University of Mexico, Mexico City, 04510, D.F., Mexico

Echeverria O.M.:
 Centre of Electron Microscopy, University of Lausanne, 27 Bugnon, Lausanne, CH-1005, Switzerland

 Laboratory of Electron Microscopy, Department of Biology, Faculty of Sciences, National Autonomous University of Mexico, Mexico City, 04510, D.F., Mexico

Fakan S.:
 Centre of Electron Microscopy, University of Lausanne, 27 Bugnon, Lausanne, CH-1005, Switzerland

Leser G.:
 Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, 60637, IL, United States

Martin T.E.:
 Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, 60637, IL, United States
ISSN: 00095915
Editorial
Springer-Verlag, 233 SPRING ST, NEW YORK, NY 10013 USA, Estados Unidos America
Tipo de documento: Article
Volumen: 99 Número: 1
Páginas: 44-51
WOS Id: A1990CX94000006