Figure 8.

Ct-RSF colocalizes extensively with hrp45 and U2 snRNP on pre-mRNAs. Polytene chromosome I from salivary gland cells was isolated and stained with antibodies directed against Ct-RSF, hrp45, and U2 B″. In A, chromosome I was double-stained for Ct-RSF and hrp45. All stained gene loci were immunolabeled for both proteins. In some cases, staining for hrp45 was considerably stronger than for Ct-RSF (arrowheads). In B, chromosome I was stained for Ct-RSF and U2 B″. Most stained gene loci were labeled with both antibodies. In some cases, staining for Ct-RSF was relatively much stronger than for U2 B″ (arrows), and for others, staining for U2 B″ was relatively stronger (arrowheads). In C, RNase treatment abolished staining for Ct-RSF and hrp45, double staining (left), phase contrast (right). Bars, 10 μm.