Fig. 4. Expression of Cul1 in the Drosophila germarium. (A-C) The Cul1 protein (red) is a nuclear protein but in the wild-type germarium mostly associates with the spectrosome (arrow) and the fusome (stained with antibodies against the Hts protein, green). (D-F) In encore mutant germaria, Cul1 association with the fusome is much-reduced (inset) and the Cul1 staining is prominently nuclear. Wild-type and encore mutant flies were raised at 29°C. (G) Genetic interactions between encore and cul1, UbcD2 and effete alleles. Reduction of cul1 gene dose in an encore mutant background enhances the 32-cell egg chamber phenotype from 27 to 65% at 25°C and from 3 to 44% at room temperature (RT). Enhancement of the phenotype from 27 to 60% at 25°C and from 3 to 17% at room temperature is also seen by reducing the gene dose of UbcD2. More dramatic enhancement from 27 to 82% at 25°C and from 3 to 75% at room temperature is observed when effete gene dose is reduced. Similar results were obtained using different cul1 and effete alleles.