A sequence of dependent stages in the development of Dictyostelium discoideum

Abstract

Eleven marker enzymes which accumulate during discrete stages of development in Dictyostelium discoideum were followed in two independent temperature-sensitive mutant strains. Strain TS2 has a temperature-sensitive period during aggregation and remains as a smooth lawn at the nonpermissive temperature (27°C). It develops normally at 22°C. Strain DTS6 has a temperature-sensitive lesion in the post-aggregation stage and fails to form slugs at 27°C. Early enzymes accumulate in these strains at the nonpermissive temperature but late stage-specific enzymes fail to accumulate at 27°C. The pattern of accumulation of specific enzymes in these and other morphological mutants defines a linear dependent pathway of at least eight steps which determines temporal differentiation in this organism. Development in Dictyostelium is also dependent on environmental cues which determine the onset of differentiation and the preparation for culmination.