Fig. 1. Phenotypes of the ptr11 mutant. (A) The cut phenotype observed in ptr11-1. ptr11-1 and wild-type 972 cells cultured at 37°C for 4 hours were stained by DAPI. The undivided nucleus was cleaved by a septum in ptr11-1. (B) ptr11-1 cells cultured at 26°C were shifted to 37°C for 4 hours and then subjected to in situ hybridization with the oligo dT probe. Poly(A)⁺ RNA accumulated in the cut phenotype nuclei at 37°C in ptr11-1. (C) ptr11-1 has no apparent defects in protein transport. The plasmid expressing Pap1p fused with GFP was introduced into cells and then localization of the expressed fusion protein was examined in the absence (a,b) or presence (c,d) of LMB at 37°C.