Fig. 1. Effect of the nak1/orb3 deletion on morphology, actin cytoskeleton and cytokinesis of fission-yeast cells. (A) The nak1/orb3 deletion phenotype. Diploid cells lacking one copy of nak1/orb3 were sporulated; the spores were dissected and incubated at 25°C, and microphotographs were taken 48 hours later. One example of wild-type (WT) and three of nak1/orb3 microcolonies are shown. (B,C) Phenotype of nak1/orb3 cells after loss of a complementing nak1/orb3 plasmid. A nak1/orb3 strain complemented with the plasmid pREP4X-nmt1-nak1/orb3 and a wild-type strain were grown without selection. Fixed cells were stained with rhodamine-phalloidin for actin and with DAPI to show the nuclei. Bars, 10 µm.