Sporulation delay by stable cAMP analogues in the slime moldPhysarum polycephalum

Abstract

Plasmodial cells of the slime moldPhysarum polycephalum become competent for sporulation following a prolonged period of starvation in darkness. Then sporulation can be induced by illumination. Microinjections of the stable (Sp)- and (Rp)-diastereoisomers of adenosine cyclic 3',5' monothionophosphate before and during a sensitive period from the start of illumination until 5 h after lead to a significant delay in the sporulation process.Both of the diastereoisomers of cyclic AMP prolong the time for sporangia to form in darkness. However, the (Sp)-diastereoisomer is more effective and causes morphological changes in plasmodia.The experimental data suggest that cyclic AMP is decisively involved in light-induced differentiation in the lower eukaryotoPhysarum polycephalum.

Two potential evolutionary origins of the fruiting bodies of the dictyostelid slime moulds

“…Previous studies have demonstrated that the intracellular cAMP concentration of the Physarum polycephalum plasmodium spikes when development is induced by light (Akitaya, Ueda & Kobatake, ), and it continues to oscillate throughout development, including spiking again when fruiting body formation begins (Akitaya et al , ). These cAMP spikes in Physarum seem to be directly related to the enactment of development, as inhibitory cAMP analogues prevent fruiting (Brandt, Jastorff & Hildebrandt, ). As presented in Table , a homolog of the Dictyostelium discoideum acaA gene is upregulated in Physarum , while the acrA homolog is not, and a acgA homolog is absent.…”