Chromosome Research

, Volume 4, Issue 3, pp 177–181 | Cite as

Heterochromatin and ribosomal genes inAsellus aquaticus (Crust. Isop.)

  • R. Barzotti
  • F. Pelliccia
  • A. Rocchi
Technical Viewpoint


In the present investigation chromosomal preparations ofAsellus aquaticus were sequentially stained with chromomycin A3 to reveal the heterochromatic areas, hybridizedin situ with rDNA probes in order to map the ribosomal genes and finally silver stained to check the transcriptional activity of these genes. The results indicate the existence of a substantial correspondence of location and size among the heterochromatic regions and the regions over which thein situ hybridization signals spread. The ribosomal genes, quite independently of their location in the secondary constriction, can be silver stained and thus appear to be transcriptionally active. The ribosomal sequences also hybridize to the entire heterochromatic areas observed on the probable Y chromosome identified in some males of a natural population. These rRNA genes are only rarely transcriptionally active.

Key words

Asellus crustacean heterochromatin ribosomal genes silver staining 


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Copyright information

© Rapid Science Publishers 1996

Authors and Affiliations

  • R. Barzotti
    • 1
  • F. Pelliccia
    • 1
  • A. Rocchi
    • 1
  1. 1.Dipartimento di Genetica e Biologia Molecolare e Centro di Genetica Evoluzionistica del CNRUniversità ‘La Sapienza’RomeItaly

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