Figure 3: piPSCs demonstrate high telomerase activity and rapid proliferation. Telomerase activities in piPSC line 1 and 2 were significantly (p-value<0.01) higher than pig fibroblast cells (A; telomerase levels reported in units of total product generated (TPG)). piPSC line 1 showed comparable telomerase activity to WA09 hESCs control. Telomerase activity of piPSC line 1 and 2 were lower than the HeLa cell control. piPSC line 1 and 2 doubling times were 19.2 and 20 hrs respectively, which were significantly (p-value<0.01) faster than the pig fibroblast cells (37.5 hrs) and similar to the WA09 hESCs (22.7 hrs; B). piPSC lines showed a normal karyotype after 20 passages (C). Bars which are not denoted by a common letter (a-d) show a statistically significant difference, p-value<0.05.