Fig. 1.

Neocentromere material does not contain maize centromere DNA or SSR marker DNA from the maize chromosome 3 long arm. A series of SSR markers spanning maize chromosome 3 were used to probe a panel of chromosome 3 truncation lines, BC₁F_2–4/9 ‘neocentromere’ progeny, a full maize chromosome 3 disomic addition line (OMAd3.1), and the oat parent of the addition cross (Sun II). The grey bars represent BAC contigs (ctg) that correlate the SSR marker position to the IBM2 physical map. The putative ch3 breakage site maps to the gap between ctg120 and ctg121 on the short arm. Each line was also Southern blotted and probed with the major maize centromere DNA element, CentC, demonstrating the loss of the original centromere in neocentromere lines.