Figure 4

Telomere length of the platypus. (a) Telomere length was determined by terminal restriction fragment (TRF) length analysis as described in Material and Methods section. This analysis included DNA isolated from quail, duck and chicken embryos, human (BD Biosciences Clontech, Cat. No. S0950), spleen from 2 month-old male mice (strain C57BL/6), lung from toad Xenopus tropicalis, opossum Monodelphis domestica, and platypus (M1, F1 and F2). The amount of DNA analyzed for F2 was higher (5 μg) than for all other samples (3 μg). The molecular weights (kb) are indicated on both sides of the picture. (b) Fluorescence in situ hybridization with Cy3 primary conjugated telomere repeat (TTAGGG 42 mer) probe (red signal), on female platypus metaphase spreads. Platypus chromosome 1 has large interstitial telomeric repeats. Scale bar = 10 μm.