Fig. 2

Overexpression of Pot1a enhances HSC proliferation activity. a–c Control GFP or Pot1a-transduced LSK cells isolated from 8 week-old mice were cultured for 2 weeks and their ability to form colonies was analyzed. a Representative colonies from control GFP (left) and Pot1a-transduced LSK cells (right) after 2 weeks in vitro culture. Scale bar, 0.5 mm. b Number of CFU-Cs. c Number of HPP-CFCs. Data are expressed as the mean ± SD (n = 3, *p < 0.01 by t-test). d, e Control GFP or Pot1a-transduced LSK cells were clone-sorted and cultured for 2 weeks in SF-O3 medium supplemented with SCF (20 ng ml^–1), TPO (50 ng ml^–1), IL-3 (20 ng ml^–1) and EPO (1 U ml^–1). d Development of colonies from single cells after 2 weeks in vitro culture. e Number of colonies derived from single cells after 1–3 weeks in vitro culture. Each colony was classified into three categories by their size (<1 mm, ≥1 mm, ≥2 mm). Data are expressed as the mean ± SD (n = 3, *p < 0.01, **p < 0.05 by Tukey’s test). f Control GFP or Pot1a-transduced 8 week-old LSK cells were cultured for 7–14 days. Subsequently, 5 × 10³ GFP⁺LSK cells were transplanted into lethally irradiated mice. The number of recipient mice that showed long-term reconstitution of donor cells (>1% of GFP⁺Ly5.1⁺ cells in PB) is shown