Table 2

Frequency of rDNA sites in the short and long chromosome arms
Sites Number of karyotypes Short arms Centromeric sitesa Long arms Total p-valueb
Singlec 220 342 (77.7%) 4 (0.9%) 90 (20.9%) 440 0.000001
Multiple 509 2,430 (68.9%) 132 (3.7%) 964 (27.3%) 3,526 0.000001
Total 729 2,772 (69.9%) 138 (3.5%) 1,056 (26.6%) 3,966 0.000001

a Sites between the short and long arms whose exact position was not identified.

b Chi-square comparison against an equal distribution of sites per arm.

c Karyotypes with a single pair of sites.

Roa and Guerra

Roa and Guerra BMC Evolutionary Biology 2012 12:225   doi:10.1186/1471-2148-12-225

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