Figure 6.
PIWI protein localization in OSS cells appears nucleoplasmic and not specific for any chromatin state. Triple staining of PIWI and DAPI with SU(VAR)205 (also known as HP1a) (A), H3K9me3 (B), H3K27me3 (C), H3K4me3 (D), and Polycomb (PC) (E). Arrowheads mark the location of the chromocenter, a DAPI-dense congregation of heterochromatin. PIWI is specifically absent from the chromocenter and does not overlap appreciably with either markers of silent or active chromatin. Some PIWI foci are near Polycomb foci, but these appear to be incidental and are never overlapping (arrows, E).
