Fig. 1. S. pombe fkh2⁺. (A) Schematic representation of the predicted 642 amino acid S. pombe Fkh2p, forkhead-like protein (SPBC16G5.15c) (Wood et al., 2002). Positions of the forkhead domain (FHD; 232-342) and the forkhead associated domain (FHA; 78-158) are shown. Arrow indicates position of the C-terminal truncation clone (1-392) that suppresses mcs3-12 wee1-50 cdc25-22. Phylogenetic tree showing the relationship between S. cerevisiae and S. pombe forkhead polypeptides, based on multiple sequence alignment, generated using the DNA cluster method in the Megalign programme based on a Jotun Hein algorithm (DNASTAR). (B) fkh2⁺ is non-essential. Heterozygous diploids containing a fkh2::kan^R (fkh2) and a wild-type allele were sporulated on EMM. Asci were separated by tetrad dissection and spores germinated on YE for 4 days, before replica plating on YE plus G418. (C) fkh2 cells have a variable length at division. Micrographs of wild-type (GG 1) and fkh2 (JM 2286) cells, growing in liquid EMM at 28°C. The length of 100 septating cells was measured and the mean length and standard deviation measured. Bar, 10 µm. (D) fkh2 (JM 2286) cells show abnormal septation. Fluorescent micrographs of fkh2 cells growing in liquid EMM at 28°C. Cells were fixed, the DNA stained with DAPI and septa marked with calcofluour. Representative images illustrating the range and incidence of septation defects (estimated from 100 cells) are shown. Arrows indicate positions of septa. Bar, 5 µm.