Nuclear actin-related protein is required for chromosome segregation in Toxoplasma gondii

► Toxoplasma clone 13-20C2 is a conditional-lethal mitotic mutant. ► Temperature sensitivity was rescued by nuclear actin-related protein 4a. ► A single mutation in the helical domain of TgARP4a leads to mis-localization. ► While a lethal defect, daughter and spindle structures still form normally. ► Thus, division coordination likely requires both microtubule organizing centers.