The nuclear acidic proteins from haploid and diploid cell states of Physarum polycephalum.

The free-living haploid gametes of the Myxomycete Physarum polycephalum are biflagellate phagocytic cells displaying gross morphological and biochemical differences as compared to the diploid plasmodium. The residual acidic chromatin and nucleolar proteins from gametes compatible for mating-type allele have been examined and compared to identical fractions from the diploid plasmodium. The proteins from both gamete mating types are identical yet major differences in the complement of these proteins occur following karyogamy and plasmodial formation. These differences occur in a fraction of acidic chromatin proteins previously shown to contain polypeptides which undergo dramatic changes during differentiation of the diploid plasmodium.