Fig. 4. Characterization of Daxx knockout (KO) embryos and cell line. (a) Embryos were collected at the indicated days after mating (E), genotyped for Daxx wild type (wt) and KO and photographed. At E8, Daxx^–/– embryos were developmentally retarded and were prominently so by E10.5. At E11.5, Daxx^–/– embryos started to dissolve and were completely disintegrated by E12.5 (inset in Daxx^–/– E12.5 shows 40x magnification). Daxx^+/– embryos did not differ developmentally from Daxx^+/+ embryos. (b) Genotyping of Daxx^–/–, Daxx^+/– and Daxx^+/+ cell lines by PCR indicating the presence of corresponding alleles, whereas controls (wt control, KO control, H₂O) demonstrated the specificity of the signals. (c) Western-blot analysis of Daxx^–/–, Daxx^+/– and Daxx^+/+ cell lines. Daxx-specific signal (arrow) was present in HEp2, Daxx^+/+ and Daxx^+/–, but not in Daxx^–/– cells. Unspecific signal is marked by the asterisk. (d-g) Cells labeled for Daxx and PML demonstrate colocalization of Daxx and PML to ND10 in Daxx^+/+ (d) and Daxx^+/– (e), but not in Daxx^–/– (f), cells. (g) Daxx^–/– cells double-labeled for ATRX and PML show ATRX accumulated in heterochromatin but not at ND10.