Use of fluorochromes chromomycin A₃ and DAPI to study constitutive heterochromatin and NORs in four species of bats (Phyllostomidae)

SUMMARY

Metaphase chromosomes of Artibeus lituratus, A. jamaicensis, A. cinereus and Phyllostomus discolor have been analyzed by C-banding and staining with base-specific fluorochromes for a better characterization of constitutive heterochromatin. Slides pretreated for C-banding and stained with DAPI/DA (CB-DAPI) have shown a pattern similar to that obtained by C-banding (CBG) for the above species. CB-CMA₃ staining evidenced telomeric blocks in the short arms of some chromosomes and in the long arm of the Y₁ in A. lituratus and A. jamaicensis. In P. discolor, however only R-banding pattern was visualized. Triple staining CMA₃/DA/DAPI revealed R-banding pattern in all these species, and only in P. discolor was possible to detect small DAPI-positive blocks in the pericentromeric regions. Sequential staining AgNO₃/CMA₃/DAPI revealed that the nucleolar organizer regions in A. lituratus and A. jamaicensis are CMA₃ positive and DAPI neutral. On the other hand they are CMA₃ neutral in P. discolor.

Key words:

• chromosomes
• constitutive heterochromatin
• fluorochromes
• NORs
• Artibeus
• Phyllostomus