TY - JOUR TI - Symbiont location, host fitness, and possible coadaptation in a symbiosis between social amoebae and bacteria AU - Shu, Longfei AU - Brock, Debra A AU - Geist, Katherine S AU - Miller, Jacob W AU - Queller, David C AU - Strassmann, Joan E AU - DiSalvo, Susanne A2 - Ruzzini, Tony A2 - Baldwin, Ian T VL - 7 PY - 2018 DA - 2018/12/31 SP - e42660 C1 - eLife 2018;7:e42660 DO - 10.7554/eLife.42660 UR - https://doi.org/10.7554/eLife.42660 AB - 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 the social amoeba Dictyostelium discoideum and their relationships with bacterial symbionts, Burkholderia hayleyella and Burkholderia agricolaris. Only about a third of field-collected amoebae carry a symbiont. We cured and cross-infected amoebae hosts with different symbiont association histories and then compared host responses to each symbiont type. Before curing, field-collected clones did not vary significantly in overall fitness, but infected hosts produced morphologically different multicellular structures. After curing and reinfecting, host fitness declined. However, natural B. hayleyella hosts suffered fewer fitness costs when reinfected with B. hayleyella, indicating that they have evolved mechanisms to tolerate their symbiont. Our work suggests that amoebae hosts have evolved mechanisms to tolerate specific acquired symbionts; exploring host-symbiont relationships that vary within species may provide further insights into disease dynamics. KW - Burkholderia KW - amoebae KW - symbiosis JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -