Social Amoeba Calculate To Communicate

Slime mold can ‘calculate’ the fold-change of signaling molecules, an ability that helps it behave like a multicellular organism.
                                           

Rather than relying on the absolute change in the levels of signaling molecules, the soil-dwelling social amoeba Dictyostelium responds to fold-change of cell-to-cell communication molecules. These findings, published in the Proceedings of the National Academy of Science, could be applied to other scenarios where intercellular communication is important, such as infection, immunity and embryonic development. Cell-to-cell signaling plays a pivotal role in cellular and tissue organization. A solid communications medium analogous to phone cables seems ideal for establishing the smooth transmission of information between cells.

In the present study, a research group led by Associate Professor Satoshi Sawai at the University of Tokyo set out to find out how Dictyostelium— an organism known as a social amoeba that shows conditional multicellularity—can communicate with each other even under conditions of varying cell density. Through quantitative live-cell imaging with a fluorescence microscope of single cell-level response to signaling molecules, the research group revealed that the Dictyostelium cells’ response remains identical under various background concentrations of stimulus as long as the fold change is the same. In other words, a change in the stimulation level from one to two produces the same result as that from two to four, both representing a twofold change, although the change difference varies.