Enrichment of ATRX at telomeres in mouse ES cell lines, ES129.1 and W9.5. Two sources of antibodies against ATRX (H300 and D19) were used in immunofluorescence analysis. (A,B) In interphase ES129.1 and ES-W9.5 cells, ATRX (Aiii,Biii, green; H300) was found at the telomeres (arrows) and pericentric heterochromatin (for ATRX localization at pericentric heterochromatin, as indicated by centromeric CREST staining, see Supplemental Fig. S1). Telomeric localization of ATRX (Aiii,Biii, green) was confirmed by telomere FISH (Aii,Bii, red). (C) Immunofluorescence analysis using a second source of antibody also showed ATRX (ii, red; D19) enrichment at the telomeres (arrows) in interphase ES129.1 cells, as evident from its colocalization with TERF1 (iii, green).
