Figure 5. The effects of non-canonical 5′ splice sites are context dependent.

(a) RT–PCR for the tif212 intron and 5′SS mutations in the context of TER1. (b) Northern blot for TER1 containing introns from protein-encoding genes with non-canonical 5′SS (GUCAGU, lanes 2–4; GUCUGU, lane 5). (c) Schematic of mechanisms that promote spliceosomal cleavage of telomerase RNA in different organisms. LC, loading control.