Fig. 5. Ct-eIF4H is not bound to nascent pre-mRNAs. (A) Isolated C. tentans polytene chromosome IV was probed with anti-Ct-eIF4H antibodies. No staining of the transcriptionally active BR gene loci (BR1, BR2 and BR3), or of other gene loci could be detected. Bar, 10 µm. (B) The same chromosome viewed in phase contrast.