C-banding (a, d), CMA3 staining (b, e, f) and FISH using as probes DOP-PCR (c, g), 18S rDNA-green and TTAGG-red (h) and U2 snDNA (i) in meiotic cells of E. k. koebelei with B chromosomes (d–i) and without them (a–c). a, h late pachytene b early diakinesis c, d, g diplotene e, i metaphase I f zygotene. Images d–g partially highlight B chromosomes. X, B and other chromosomes harboring specific signals are indicated; arrowheads point to the centromeres of B chromosomes. Inserts in g, h highlight B chromosomes. Bar: 5 µm.