Efficient telomerase-mediated elongation of telomeres in DKO cells.

<p>(<b>A</b>) TRF analysis of par and DKO cells infected with empty vector (ev) or hTERT retroviruses. Genomic DNA was collected 2, 5 and 9 days (d) after infection, digested with <i>Rsa</i>I and transferred to a nylon membrane. The same membrane was first hybridized with a probe detecting 10q TRFs and successively with a probe detecting total telomeres. (<b>B</b>) STELA of 15q telomere length using the same DNA as in <b>A</b>. Marker molecular weights are on the left in kilobases. (<b>C</b>) Box plot representation of 15q telomere lengths. Average telomere lengths in kilobases and the number of total telomeres analyzed (n) are indicated for each sample. (<b>D</b>) 15q telomere elongation rates expressed as average telomere length at different population doublings. Note that for par cells, only three time points were used because no statistically significant difference in average telomere length was measured between day 5 and day 9.