Chromosomal mapping of the 5S and nucleolar rDNA in Engystomops freibergi. Karyotype of E. freibergi hybridized with the probe containing the entire type I 5S rDNA repeating (A), and with the probe containing the entire type II 5S rDNA repeating (B). Arrows indicate the NORs as reported by Targueta et al.  for the same specimens (A: ZUEC 14440; B: ZUEC 14458). The morphological difference between the homologues of pair 11 in A, and B results from a C-band and NOR heteromorphism, not observed in the ZUEC 14435 female whose karyotype in shown in Figure7A (for details about this heteromorphism, see ).
Rodrigues et al. BMC Genetics 2012 13:17 doi:10.1186/1471-2156-13-17