Characterization of thermosensitive mutants of Physarum polycephalum a plasmodial screening method for cell cycle mutants based upon synchronization at the restrictive temperature

Summary A screening procedure for cell cycle mutants among is mutants of Physarum has been developed for unsynchronized microplasmodia. The synchronization of the microplasmodia and the ratio of pre- to post-mitotic nuclei were evaluated after a transient shift-up to the non-permissive temperature. In contrast with wild type and is mutants not blocked in a cell cycle event, putative cell cycle mutants were synchronized. Among them, three strains which showed a reduction of DNA synthesis had an abnormally increased ratio of pre- to post-mitotic nuclei. Thus, this methodology seems to be efficient and more rapid than the previously published procedures for detecting cell-cycle mutants of Physarum.