Figure 1

Male meiotic cells and karyotype of Dichotomius geminatus. Conventional staining of metaphase I chromosomes of 0B individuals (a) and 1B individuals (b); C-banded karyotype (c), metaphases I of 0B (d) and 1B (e) individuals and metaphases II of B-carrying individual (f). Silver nitrate staining in initial prophase (g). The arrows indicate the sex bivalents (Xyp), full and empty arrowheads indicate the B chromosomes and the nucleolar organizer region (NOR), respectively, and the * (asterisk) indicates the chromosome pairs with additional heterochromatic blocks. Bar=5 μm.