Popis: |
In the present study, somatic metaphase chromosomes of the millipede Enologus oxypygum (Diplopoda: Julida) were hybridized in situ with a sea urchin (Echinodermata) ribosomal probe (prR14) in order to map major RNA genes (rDNA). Chromosomal preparations were also silver stained (Ag-NOR) to evaluate the rDNA transcriptional activity. Our results indicate that RNA genes are throughout heterochromatin in eight chromosomes involving 1/4 of the total heterochromatin which, in this species, is about 67% of the total DNA. Ag-NOR and FISH patterns were not coincident. |