Details of B chromosome of Cestrum strigilatum at meiosis, and FISH using the B probe against the karyotype. A Metaphase I showing the B as univalent, laterally located (arrow) B Anaphase I showing the lagging B univalent moved to one of the complements (arrow) C Late anaphase II close to one of the four complements. Note that the chromatids are partially separated (arrow) D Mitotic metaphase stained with DAPI. Arrowhead indicates the B E Mitotic metaphase hybridized with B probe. Note that some DAPI bands in D appear negative in E, but others do not. Large arrows indicate FISH signal colocalized with 5S rDNA (see also Fig. 2), small arrows point out intercalary and terminal FISH signals, and arrowhead indicates the B completely stained by probe. Bar = 10 µm.