Anaphase I disturbed, spindle persists. Mutation found following seed treatment by N-nitroso-N-methylurea. Mutant ms28 plants exhibit abnormalities in chromosome segregation and cytokinesis during meiosis I and meiosis II. The spindle fiber assembly process is either eliminated or strongly delayed(M. Albertsen). Polar microtubules excessive, astral; normal phragmoplast formation fails to occur and dissassembly is delayed. Uncovered by TB-1Sb, not by TB-1Sb-2Lc. Probable allele of dv1. Genetic 2005 1 coordinates determined from these recombination and map data: ms28 TB-1Sb(1); see MaizeGDB ID:104725. This gene was originally curated in MaizeGDB Database and the map position was displayed on the maize bins map if feasible.