Analysis of the nucleolar organizing regions in the ant Tapinoma nigerrimum (Hymenoptera, Formicidae)

Heredity (Edinb). 1997 Jun:78 ( Pt 6):578-82. doi: 10.1038/hdy.1997.96.


This study analyses the NORs of Tapinoma nigerrimum, a species that, as known from previous studies, has various chromosomes which carry a NOR site. The analysis was made by a combination of three methods: silver nitrate staining, in situ hybridization with fluorescein-or digoxigenin-labelled probes, and staining with the CG-specific fluorochrome chromomycin A3. The silver staining technique showed an Ag-positive region on chromosome 6 and on various other chromosomes. However, the application of in situ hybridization techniques showed only one positive signal in the proximal region of the short arm of chromosome 6 of T. nigerrimum. Similar results were observed by CMA banding. The absence of rDNA genes or the presence of only a small number of these, not detectable with the above probes, might explain the absence of hybridization signal in the remaining chromosomes.

MeSH terms

  • Animals
  • Ants / genetics*
  • Chromomycin A3 / chemistry
  • DNA Probes
  • DNA, Ribosomal / genetics
  • Digoxigenin / chemistry
  • Diploidy
  • Female
  • Fluorescein
  • Fluoresceins / chemistry
  • Genes, Insect
  • Haploidy
  • In Situ Hybridization, Fluorescence / methods*
  • Male
  • Nucleolus Organizer Region / genetics*
  • Silver Nitrate / chemistry
  • Silver Staining


  • DNA Probes
  • DNA, Ribosomal
  • Fluoresceins
  • Silver Nitrate
  • Chromomycin A3
  • Digoxigenin
  • Fluorescein