Figure 6.

The BTBIVR region depends on an intact ORF1 for ring canal localization. The KREP domain is necessary and sufficient for ring canal localization. Myc:ORF1 localizes to and rescues kel^DE1 ring canals (A). Myc:ORF1-R localized to ring canals in wild-type egg chambers (B) but not to ring canals in kel^DE1 egg chambers (C). In wild-type egg chambers (B), myc:ORF1-R also formed punctate structures in the cytoplasm of the nurse cells. These structures contain no detectable PY protein, hts-RC, or actin (not shown) and appeared to be dependent on the dosage of myc:ORF1-R. Similar structures were seldomly observed in kel^DE1 egg chambers (C). Myc:BTBIVR localized to ring canals in wild-type egg chambers (D) but not to ring canals in kel^DE1 egg chambers (E). Myc:KREP was not detected on ring canals in wild-type egg chambers (F) but did localize to ring canals in kel^DE1 egg chambers (G). Some nuclear localization (F, arrow) of KREP was observed in wild-type egg chambers. All egg chambers were stained with anti-myc 9E10 antibodies. Bars: (A) 30 μm; (B–G) 30 μm.