C) Replacing the Nter of Sen1 by the CID of Nrd1 restores viability. Growth test performed in the same conditions as in figure 3A but in the presence of a TRP1-plasmid carrying the SEN1 versions indicated in the scheme on the left. The growth of the strain expressing the Nrd1 CID-sen1∆Nter chimera in 5-FOA implies that this gene can support viability. 