TY  - JOUR
A1  - Scheer, Ulrich
A1  - Trendelenburg, Michael F.
A1  - Franke, Werner W.
T1  - Transcription of ribosomal RNA cistrons: Correlation of morphological and biochemical data
N2  - Electron microscopic spread preparations of oocyte nucleoli (lampbrush stage) of various amphibians are quantitatively evaluated and the length distributions of repeat-, matrix-, and spacer-units along the rRNA cistron containing axes are given. The correlation of the matrix unit data with the gel electrophoretic pattern of labelled nuclear RNA from the same oocytes is examined. The mean value of the matrix unit corresponds fairly well to a 2.6 million D peak of pre-rRNA but the distribution of both matrix units and labelled pre-rRNAs shows an asymmetrical heterogeneity indicating the existence of some larger primary transcription products of rDNA. Novel structural aspects are described in the spacer regions which suggest that transcription does also take place in DNP regions between the matrix units. A special "prelude piece" coding for approx. 0.5 million D of RNA is frequently visualized in the spacer segments at the beginning of a matrix unit. Possible artifacts resulting from the preparation, the relative congruence between the data obtained using both methods, and the functional meaning of the findings are discussed against the background of current concepts of structural organization and transcription products of nucleolar DNA.
Y1  - 1973
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32195
ER  - 
TY  - JOUR
A1  - Franke, Werner W.
A1  - Trendelenburg, Michael F.
A1  - Scheer, Ulrich
T1  - Natural segregation of nucleolar components in the course of plant cell differentiation
N2  - Segregation of the nucleolar components is described in the differentiated nucleus of the generative cell in the growing Clivia and Lilium pollen tubes. This finding of a natural nucleolar segregation is discussed against the background of current views of the correlations of nucleolar morphology and transcriptional activity.
Y1  - 1973
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32182
ER  - 
TY  - JOUR
A1  - Franke, Werner W.
A1  - Scheer, Ulrich
T1  - The ultrastructure of the nuclear envelope of amphibian oocytes: a reinvestigation. II. The immature oocyte and dynamic aspects
N2  - No abstract available
Y1  - 1970
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32102
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
A1  - Thiry, Marc
A1  - Goessens, Guy
T1  - Structure, function and assembly of the nucleolus
N2  - No abstract available
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32057
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
A1  - Weisenberger, Dieter
T1  - The nucleolus
N2  - No abstract available
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32037
ER  -