Karyotypic characterization of Acipenser gueldenstaedti with C-, AgNO3 and fluorescence banding techniques

Fontana F. Lanfredi M. Rossi R. Bronzi P. Arlati G.

A karyotypic analysis was carried out on the Russian sturgeon using C- and Ag-NOR banding techniques and base specific DNA-binding fluorochromes. The standard karyotype is 2n = 258+/-4. Nucleolar organizer regions are localized on each of the telomers of four metacentric chromosomes, and on one telomer of four metacentric, four acrocentric, and one large metacentric. C-bands are mainly located at the centromeric regions of the acrocentric chromosomes. The biarmed chromosomes exhibit either weak or absent C-bands, but four metacentrics are completely heterochromatic. By means of double staining with complementary fluorochromes, chromomycin A(3) and DAPI, a pattern of fluorescent regions is recognizable. Interspersion of the opposite DNA base pairs along the chromosomes is discussed.

Author Keywords: Acipenseridae; karyotype; chromosome banding

Addresses: Fontana F (reprint author), UNIV FERRARA, DIPARTIMENTO BIOL, SEZ BIOL EVOLUT, VIA L BORSARI 46, I-44100 FERRARA, ITALY