Figure 3.

The Ur element comprises a short stem–loop and a consensus UAYYUU motif. (A) Diagram of the ICR between Y37E3.8 and rla-1 indicating the two components of the Ur element. Shown below is the nucleotide sequence of this Ur element and that in the previously described gpd-3 operon (Huang et al. 2001). (B) Bioinformatic analysis comparing the percentages of genes containing UAYYUU upstream of and downstream from the 3′ end cleavage site (cs) within (gray squares) or not within (black diamonds) operons. (C) Nucleotide sequences of presumptive Ur elements of different nematode species shown for four operons. The trans-spliced downstream gene name is given.