Fig. 5. DPY-21 is recruited to X chromosomes by components of the dosage compensation complex. (A-G) Confocal images of wild-type (A), sdc-2(y74) (B), sdc-3(y126) (C), dpy-26(y199) (D), dpy-27(y167) (E), dpy-28(s939) (F) and sdc-1(n485) (G) mutant embryos co-stained with DPY-21 antibodies to amino acids 467-1102 (green), DAPI (blue) and an X-chromosome-specific FISH probe (red) or SDC-3 antibodies (red). (A) In wild-type embryos, foci of DPY-21 staining co-localize with X chromosomes identified by FISH. (B-F) DPY-21 accumulates in dosage compensation mutant embryos, but foci of DPY-21 staining in sdc-2(y74) (B), sdc-3(y126) (C), dpy-26(y199) (D), dpy-27(y167) (E) and dpy-28(s939) (F) mutants are not coincident with the X chromosome. Thus DPY-21 requires sdc-2, sdc-3, dpy-26, dpy-27 and dpy-28 for its localization to X but not for its stability. (G) By contrast, neither DPY-21 nor SDC-3 requires sdc-1 for its localization to X. Insets show the enlargement of a single nucleus indicated by the arrow. Scale bars: 5 µm.