B chromosome variants in Prochilodus lineatus (Characiformes, Prochilodontidae) analyzed by microdissection and chromosome painting techniques

Figures & data

Figure 1. Somatic chromosomes of Prochilodus lineatus after in situ hybridization using a B acrocentric (B_a) chromosome variant probe. In (a) metaphase cell with two metacentrics and one acrocentric variant B chromosome; (b) metaphase with one metacentric variant B chromosome; (c) metaphase with one submetacentric variant B chromosome. Arrowheads highlight metacentric, submetacentric and acrocentric B chromosome variants. Bar = 10 μm.

Figure 2. Somatic chromosomes of Prochilodus lineatus after in situ hybridization using a B metacentric (B_m) chromosome variant probe. In (a) metaphase cell with one metacentric variant B chromosome; (b) metaphase with two metacentrics and one acrocentric variant B chromosome; (c) metaphase with one submetacentric variant B chromosome. Arrowheads highlight metacentric, submetacentric and acrocentric B chromosome variants. Bar = 10 μm.

Figure 3. Somatic chromosomes of Prochilodus lineatus after in situ hybridization using a B acrocentric (B_sm) chromosome variant probe. In (a) metaphase cell with two metacentrics and one acrocentric variant B chromosome; (b) metaphase with one metacentric variant B chromosome; (c) metaphase with one submetacentric variant B chromosome; (d) metaphase after C-banding treatment showing heterochromatic blocks in the centromeric and pericentromeric regions on chromosomes of the normal complement. Arrowheads highlight metacentric, submetacentric and acrocentric B chromosomes and arrows points to marked sites located on chromosomes of the normal set. Bar = 10 μm.

Figure 4. Proposed model for the origin of B chromosome variants in Prochilodus lineatus.