Figure 1. Telomere length dimorphism in the Tasmanian devil.

Q-FISH of metaphases from a male and a female Tasmanian devil (lymphocytes and skin fibroblasts, respectively) and a DFTD cell-line using a Cy3-labelled (CCCTAA)₃ PNA probe. (A) In both male and female Tasmanian devils, homologous chromosomes are characterised by striking differences in telomere length. In male devils, telomeres on the Y chromosome are consistently long and X chromosome telomeres are short. DFTD telomeres are uniformly short. (B) Frequencies of male, female and DFTD telomere fluorescence intensities demonstrate an unusual bimodal distribution of long and short telomeres in male and female devils with marked heterogeneity of the long telomere subset. Telomere lengths are compared to those of C57BL/6 mouse fibroblasts.