Fig. 2. Sister chromatid cohesion in cells expressing byr1^DD. Segregation of sister chromatids in meiosis I (A,B) and in meiosis II (C,D). (A,C) h⁺/h^– diploid (TG157) cells (left), h^–/h^– diploid (TG143) cells carrying pREP1-byr1^DD (middle), and h^– haploid (AY193-3A) cells carrying pREP81-byr1^DD (right) were induced to undergo meiosis and observed by fluorescence microscopy without fixation. The lys1 locus near the centromere (green) was stained using the lacI-GFP/lacO recognition system. In diploid cells, one of two lys1 loci was stained. The nucleus (white) was stained with Hoechst 33342. Scale bars: 5 µm. (B,D) Patterns of segregation were classified into two categories in B or five categories in D based on the number of nuclei (open circles) and the number of lys1-GFP signals (dots in the circle). Numbers of the cells examined (N) are shown at the top of each graph.