BACs mapped by FISH to (a–d) the sex chromosomes and (e–g) autosomes orthologous to the human X on male platypus metaphase spreads: (a) CH236-72 A21; (b) CH236-3 C11; (c) CH236-20 M7; (d) (green) CH236-271 I19 and (red) CH236-165 F5; (e) (green) CH236-359 L11 (representing UltraContig462) and (red) CH236-97 I3 (chromosome 15 anchor BAC); (f) (green) CH236-427 K7 (representing UltraContig222) and (red) Ch236-330 L7 (chromosome 18 anchor BAC): (g) (green) CH236-337 O23 (representing UltraContig420) and (red) CH236-30 G14 (representing UltraContig519). Scale bars, 10 μm.