Chromosome location of the ribosomal genes in Triturus vulgaris meridionalis (Amphibia Urodela). III. Inheritance of the chromosomal sites for 18S + 28S ribosomal RNA.

In Triturus vulgaris meridionalis, the 18S + 28S rDNA sequences have been shown to be located in a number of additional chromosomal sites besides the nucleolus organizing region. The additional ribosomal sites have been found to vary as to their number and chromosomal location in different individuals of the species.--The data presented in this study concern the chromosomal distribution of the ribosomal sequences as analyzed by in situ hybridization technique in two individuals as well as in their offspring. The evidence obtained by this analysis indicates quite clearly that all 18S + 28S rRNA sites present in each individual genome are inherited according to simple mendelian principles

Chromosome location of the ribosomal genes in Triturus vulgaris meridionalis. III. Inheritance of the chromosomal sites for 18S+28S ribosomal RNA

In Triturus vulgaris meridionalis, the 18S + 28S rDNA sequences have been shown to be located in a number of additional chromosomal sites besides the nucleolus organizing region. The additional ribosomal sites have been found to vary as to their number and chromosomal location in different individuals of the species.--The data presented in this study concern the chromosomal distribution of the ribosomal sequences as analyzed by in situ hybridization technique in two individuals as well as in their offspring. The evidence obtained by this analysis indicates quite clearly that all 18S + 28S rRNA sites present in each individual genome are inherited according to simple mendelian principles

Chromosome location of the ribosomal RNA genes in Triturus vulgaris meridionalis (Amphibia, Urodela)

The mitotic chromosomes of six specimens from Triturus vulgaris meridionalis have been examined by both in situ hybridization with 3H 18S + 28S rRNA and AS-SAT staining method. The results of these two sets of experiments can be summarized as follows: 1) in each specimen the NORs and the additional ribosomal sites, which react positively to in situ hybridization with 3H 18S + 28S rRNA, are also stained by silver; 2) other chromosomal regions, which do not hybridize in situ with 3H 18S + 28S rRNA, are on the other hand stained by the AS-SAT method. These latter AG-positive sites show a species-specific pattern of chromosomal distribution