Characterization of C-heterochromatin in four species of Hydrozoa (Cnidaria) by sequence specific fluorochromes Chromomycin A3 and DAPI

Abstract

The karyotypes of Pelmatohydra oligactis (Pallas, 1766), Hydra vulgaris Pallas, 1766, Hydra circumcincta Schulze, 1914 (Hydrida, Hydridae) and Pachycordyle kubotai Stepanjants, Timoshkin, Anokhin, Napara, 2000 (Athecata, Clavidae) have been studied for the first time by using the fluorochromes DAPI, and CMA3. In all the species C-heterochromatic regions were stained brightly with DAPI, indicating that constitutive heterochromatin associated with centromeres or NORs is A-T-rich. CMA3 staining showed exceptionally rare G-C-rich clusters associated with NORs. © 2004 Taylor & Francis Group, LLC.