Fig. 3. Localisation of tagged mouse WT1 in nuclear structures of Xenopus oocytes. (A-D) Lampbrush chromosome bivalent showing the location of WT1 (+KTS) as FITC image (A), location of p116 as TRITC image (B), corresponding DAPI (C) and phase-contrast (D) images. In addition to locating to the lateral loops of the chromosomes, both WT1 (+KTS) and endogenous p116 locate to Cajal bodies (arrows in A, B and D) and to smaller nuclear particles. (E,F) In images obtained at higher power, WT1 (+KTS) is seen to be specific to the B-snurposomes (arrows) located on the surfaces of the Cajal bodies (E, FITC and F, phase contrast). (G-I) Expression of WT1 (–KTS) shows that it is restricted to the lateral loops of the chromosomes (G) and is not found in Cajal bodies (arrows in I) or in other nuclear particles. The chromosomal DNA axes are stained with DAPI (H).