FIGURE 6.
U7 snRNA can form a snRNP particle in Lsm11 mutants. (A) U7 Northern analysis of RNA isolated from Lsm11c02047/Df mutant (Lsm11) or w1118 control (WT) embryos and first to third instar larvae. Note that in the Lsm11 mutant U7 snRNA is detected in third instar larvae when all the histone mRNA is misprocessed. A U1 probe was used as a loading control. U7 snRNA migrates as a doublet as described previously (Dominski et al. 2003). (B) Reverse transcriptase (RT)-PCR analysis of RNA extracted from anti-TMG immunoprecipitates of whole third instar larvae RNA samples of the indicated genotypes. (Lanes 1–6) 10% of total input RNA; (lanes 7–12) anti-TMG IP; and (lanes 13,14) mock IP negative control. (Top panel) U7 snRNA primer pair. Note that there is no U7 present in the U7EY11305 mutant or in the control IP lane, but U7 is detected in both WT and Lsm11c02047/Df TMG IP samples. (Middle panel) U1 snRNA primer pair. Note that U1 is present in all three TMG IP samples, but not in the IP control. (Bottom panel) Ribosomal protein 49 (rp49) primer pair. Note that rp49 mRNA is not precipitated by anti-TMG antibodies because the mRNA lacks a trimethylguanosine cap.