Globin loci of the pufferfish F rubripes are located on different chromosomes.

(A) Nuclei were prepared from peripheral blood of adultFugu, fixed onto poly-L-lysine–coated slides and subjected to DNA-FISH with Fugu α- (red) and αβ-cosmid (green) probes. Four representative images, obtained by confocal scanning laser microscopy, are shown. The α- and αβ-cosmid signals are always clearly separated from each other. (B) Metaphase spreads of kidney cells isolated from colchicein-treated Fugu rubripesfingerlings were hybridized with Fugu α-cosmid (red) and αβ-cosmid (green) probes. Two chromosomes from one metaphase spread are shown. Both probes hybridize to the telomeric end of the p arm of one of the Fugu chromosomes. The chromosome with the red α-cosmid signal is much larger that the chromosome with the green αβ-cosmid signal. Original magnification × 100.