ISSN:
1573-6849
Keywords:
Ag-NORs
;
interphase rDNA organisation
;
rDNA loci
;
Silene cintrana
;
Silene rothmaleri
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Double target in situ hybridization to root tip metaphase and interphase cells of Silene cintrana and Silene rothmaleri was used to allocate the position of 18S-5.8S-25S and 5S rRNA genes. In both species, the 18S-5.8S-25S rDNA probe labelled four sites located on the short arms of two submetacentric chromosomes. Only one locus for 5S rDNA was mapped adjacent to 18S-5.8S-25S genes in a subterminal position on the centromere side: in S. rothmaleri the 5S rDNA locus was adjacent to the small 18S-5.8S-25S locus while in S. cintrana it was near the large one. The NOR activity analysed by Ag-staining in metaphase cells revealed proportionality between in situ labelling dimensions and Ag-NORs. In both species all rDNA loci were potentially active, although in S. rothmaleri a tendency for the expression of only one locus was observed. Interphase organisation analysis of rDNA showed some differences between both species that were correlated with NOR activity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009279428484
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