Joan Strassmann

Jul 19, 2024 | biorxiv.org | Israt Jahan |Trey Scott |Joan Strassmann |David C. Queller

AbstractMulticellular organisms that form by aggregation of cells arguably do not achieve high levels of complexity. Conflict among the cells is a widely accepted explanation for this, but an alternative hypothesis is that mixing cells of different genotypes leads to failures of coordination, which we call the coordination hypothesis. We empirically tested the coordination hypothesis in the social amoeba Dictyostelium discoideum. We mixed D.

May 14, 2024 | biorxiv.org | Israt Jahan |Trey Scott |Joan Strassmann |David C. Queller

AbstractSelection for cooperation or conflict in multicellular organisms that develop from a mixture of cells has been widely appreciated, but unselected effects of mixing could also have important fitness consequences to the resulting chimeras. We formalized this idea as the developmental incompatibility hypothesis and empirically tested it in the social amoeba Dictyostelium discoideum. We mixed D.

Nov 15, 2023 | biorxiv.org | Trey Scott |David C. Queller |Joan Strassmann

AbstractSymbiotic interactions may change depending on the abundance of third parties like predators, prey, or pathogens. Third-party interactions with prey bacteria are central to the symbiosis between Dictyostelium discoideum social amoeba hosts and Paraburkholderia facultative bacterial symbionts. Symbiosis with inedible Paraburkholderia allows host D. discoideum to carry prey bacteria through the dispersal stage where host amoebae aggregate and develop into fruiting bodies that disperse spores.

Sep 6, 2023 | biorxiv.org | Tyler Larsen |Israt Jahan |Debra Brock |Joan Strassmann

AbstractMany microbes interact with one another, but the difficulty of directly observing these interactions in nature makes interpreting their adaptive value complicated. The social amoeba Dictyostelium discoideum forms aggregates wherein some cells are sacrificed for the benefit of others. Within chimeric aggregates containing multiple unrelated lineages, cheaters can gain an advantage by undercontributing, but the extent to which wild D. discoideum has adapted to cheat is not fully clear.