Location of the 18S and 28S rRNA cistrons in the genome of the domestic rabbit (Oryctolagus cuniculus L).

The genomic location of rDNA in the rabbit was determined by in situ hybridization with (125)I-labeled ribosomal RNA (rRNA). The results demonstrate the presence of rRNA genes on chromosomes, 13, 16, and 20, all of which have secondary constrictions, and on the telomere of the long arm of 21. The number of genes, as assessed by grain counts, was not equally distributed among the chromosomes. Chromosome 20 had the most copies and along with 13 and 16 carried significantly more genes than 21.