Symbiont location, host fitness, and possible coadaptation in a symbiosis between social amoebae and bacteria.

摘要: Recent symbioses, particularly facultative ones, are well suited for unravelling the evolutionary give and take between partners. Here we look at variation in natural isolates of social amoeba Dictyostelium discoideum their relationships with bacterial symbionts, Burkholderia hayleyella agricolaris. Only about a third field-collected amoebae carry symbiont. We cured cross-infected hosts different symbiont association histories then compared host responses to each type. Before curing, clones did not vary significantly overall fitness, but infected produced morphologically multicellular structures. After curing reinfecting, fitness declined. However, B. suffered fewer costs when reinfected hayleyella, indicating that they have evolved mechanisms tolerate Our work suggests specific acquired symbionts; exploring host-symbiont within species may provide further insights into disease dynamics.