Relative telomere copy number is lower in DFT samples than in other devil tissues.

<p>Error bars depict standard deviations. Sample names indicate the time of collection (06 = 2006, 07 = 2007, 10 = 2010). Identical numbers represent different tissue samples collected from the same animal. Number of samples used in the analysis: primary tumours collected in 2006: N = 30, 2007: N = 13 and 2010: N = 8; metastasis: N = 4, spleen: N = 5, lung: N = 5.</p

Relative mean DFT telomere copy number increases with time (2006: N = 30, 2007: N = 13 and 2010: N = 8).

<p>Error bars depict standard deviations. Significant differences in telomere copy numbers (TCN) were observed between years 2006 and 2007 (P = 0.03) and 2006 and 2010 (P = 0.01), but no significant difference in TCN was observed between years 2007 and 2010 (P = 0.6). * indicates significant differences.</p

Telomerase activity increases over time in DFT cell lines (P = 0.037).

<p>The five cell lines originated from tumour samples collected in 2003, 2006, 2007, 2010 and 2011. Bars represent standard errors between technical repeats (N = 3).</p

The Telomere Restriction Fragment Length analysis of devil samples revealed the presence of restriction enzyme recognition sites intercalated between the telomeric (TTAGGG)n sequences, preventing an accurate estimate of TRF lengths.

<p>Sample names depict the time of collection (10 = 2010). Identical numbers represent different tissue samples collected from the same animal, S depicts spleen and T depicts DFT samples. MWM stands for molecular weight markers. CTRL 1 indicates low molecular weight control DNA (length: 3.2 kbp), CTRL 2 indicates high molecular weight control DNA (length: 10.2 kbp). Control samples were supplied in the Telo TAGGG TL Assay Kit and originated from immortal cell lines.</p

TERT and TINF2 gene expression increases with time in DFT samples.

<p>Open bars depict TERT expression, black bars depict TINF2 expression. Number of samples used in the analysis: tumours collected in 2007: N = 5 and 2010: N = 6. * depicts significant differences (P = 0.0173 and P = 0.013, respectively).</p

TERT and TINF2 genes are up-regulated in DFT samples compared to spleen (P<0.0001).

<p>Number of samples used in the analysis: tumours N = 11 and spleen N = 5. Stippled horizontal lines depict mean relative gene expression, boxplots indicate the range of standard error and bars depict 95% confidence intervals.</p