Karyotype characterization of the lake sturgeon, Acipenser fulvescens (Rafinesque 1817) by chromosome banding and fluorescent in situ hybridization.
A karyotype analysis using several staining techniques was carried out on the North American lake sturgeon, Acipenser fulvescens. The chromosome number was found to be 2n = 262 +/- 6. A representative karyotype of 264 chromosomes was composed of 134 meta- and submetacentrics, 70 telo- and acrocentrics, and 60 microchromosomes. The constitutive heterochromatin, revealed by C banding, was localized in various positions on several chromosomes, including microchromosomes. The signals of fluorescent in situ hybridization (FISH) with a HindIII satellite DNA probe were visible as centromeric heterochromatin blocks on 48 chromosomes. The telomeric repeat (TTAGGG)n detected by FISH was localized at both ends of all chromosomes and two chromosomes were entirely marked. Fluorescent staining with GC-specific chromomycin A3 showed recognizable fluorescent regions, whereas a more uniform base composition was revealed by the AT-specific 4',6-diamidino-2-phenylindole (DAPI). After silver staining, the active nucleolar organizer regions (NORs) were detected on 12 chromosomes. FISH with the 5S probe showed four signals on four small chromosomes. Our data suggest that A. fulvescens is a tetraploid species.
Department of Biology, University of Ferrara, Via L. Borsari 46, 44100 Ferrara, Italy. fon@dns.unife.it
Francesco
F
Fontana
Ronald M
RM
Bruch
Fred P
FP
Binkowski
Massimo
M
Lanfredi
Milvia
M
Chicca
Nicola
N
Beltrami
Leonardo
L
Congiu
D000818:Animals; D001482:Base Composition; D002871:Chromosome Banding; D004247:DNA / Q000737:chemistry / Q000235:genetics; D005260:Female; D005399:Fishes / Q000235:genetics*; D005456:Fluorescent Dyes; D017404:In Situ Hybridization, Fluorescence; D007211:Indoles; D007621:Karyotyping; D018598:Minisatellite Repeats; D009697:Nucleolus Organizer Region; D012834:Silver; D013194:Staining and Labeling; D016615:Telomere / Q000235:genetics
D005456:Fluorescent Dyes; D007211:Indoles; D012834:Silver; C007293:DAPI; D004247:DNA