Fig. 8. Recombinant Xp54 associates with de novo synthesized RNA. Stage III/IV oocytes expressing T7-p54 and T7-tagged histone deacetylase (HDAC) were injected with 0.1 µg of BrUTP and 0.1 µCi of ³²P-CTP six hours before isolation of nuclei. (A) Double immunostaining of lampbrush chromosomes using anti-BrdU mouse monoclonal and anti-HDAC rabbit polyclonal. Immunofluorescent (FITC-conjugated anti-mouse IgG and TRITC-conjugated anti-rabbit IgG), DAPI and phase contrast (PC) images of a representative bivalent are shown. (B) Immunoprecipitation of T7-Xp54 and T7-HDAC from nuclear extracts using anti-BrdU and anti-T7 monoclonals. Nuclear extracts from non-injected oocytes (–) are shown as negative controls. (C) Immunoprecipitation of ³²P-labelled RNA from nuclear extracts similar to those in (B) using anti-BrdU IgG and anti-T7 IgG is shown.