Figure 3.—

Localization of full-length GFP-tagged Subito and C-terminal domain proteins in stage 14 oocytes. In all the experiments discussed below, the transgenes were expressed using the P{GAL4∷VP16-nos.UTR}MVD1 driver. DNA is in blue, Subito or GFP-Subito in red, and tubulin in green. The second column shows the Subito signal from GFP (A–C) or antibody staining (D). Tubulin, along with Subito in some cases, is shown in the last column. (A) Full-length Subito fused to GFP (P{UASP:GFP-sub⁺}). (B) The C-terminal domain of Subito fused to GFP (P{UASP:GFP-sub^CT}). These females also expressed wild-type Subito from the endogenous locus. In the last column is a magnification with the DNA staining removed to show that the central focus of GFP-Subito^CT staining (arrow) is associated with thin microtubule fibers. (C) The C-terminal domain of Subito fused to GFP and expressed in the absence of wild-type Subito (sub¹/sub¹³¹; P{UASP:GFP-sub^CT}). Also shown is a magnification of the region near the karyosome with DNA staining removed to show GFP-Subito^CT staining associated with microtubule fibers. In B and C, the weak GFP staining was also observed in experiments without staining for tubulin, showing that the signal was not due to bleed through (data not shown). (D) The C-terminal domain of Subito fused to GFP and expressed in the presence of wild-type Subito (P{UASP:GFP-sub^CT}) and stained with an antibody that recognizes both the wild-type and Subito^CT proteins. As in Figure 1B, the high background is due to optimization for the low Subito signal. Bars, 10 μm.