Figure 3

Tcstv1 or Tcstv3 overexpression enhances telomere sister chromatid exchange (T-SCE) in mouse ESCs and elevates Zscan4 protein levels.

(a) Expression levels of Tert and Terc showed no significant difference among Tcstv1 OE, Tcstv3 OE and mock ESCs by qPCR analysis. Two repeated experiments with duplicated samples each. (b) Confirmation of Zscan4 protein levels in Tcstv1 OE, Tcstv3 OE and mock ESCs by western blot. Black arrow indicates Zscan4 bands. (c) Quantification of relative Zscan4 protein levels normalized to β-actin by ImageJ software. n = 4. (d) Immunofluorescence images of Zscan4 (red) and Oct4 (green) in Tcstv1 OE, Tcstv3 OE and mock ESCs (Scale bar = 20 μm) and proportion of Zscan4 positive cells. n, number of cells counted. χ² test shows no statistical difference (P > 0.05). (e) Analysis of Zscan4⁺ cells in Tcstv1 OE, Tcstv3 OE and mock ESCs by flow cytometry. (f) Representative micrographs showing T-SCE (red arrows) by CO-FISH analysis. Scale bar = 10 μm. (g) T-SCE per chromosome in Tcstv1 OE, Tcstv3 OE and mock ESCs. n, number of cells counted. *P < 0.05, **P < 0.01, compared with controls.