Spot test and spore count assay data for combinations of dictyostelid hosts infected by Paraburkholderia spp.

The social amoeba Dictyostelium discoideum engages in a complex
relationship with bacterial endosymbionts in the genus Paraburkholderia,
which can benefit their host by imbuing it with the ability to carry prey
bacteria throughout its life cycle.  The relationship between D.
discoideum and Paraburkholderia has been shown to take place across many
strains and a large geographical area, but little is known about
Paraburkholderia’s potential interaction with other dictyostelid
species.  We explore the ability of three Paraburkholderia
species to stably infect and induce bacterial carriage in other
dictyostelid hosts. We found that all three Paraburkholderia species
successfully infected and induced carriage in seven species of
Dictyostelium hosts.  While the overall behavior was
qualitatively similar to that previously observed in infections of D.
discoideum, differences in the outcomes of different host/symbiont
combinations suggest a degree of specialization between
partners.  Paraburkholderia was unable to maintain a stable
association with the more distantly related host Polysphondylium
violaceum.  Our results suggest that the mechanisms and
evolutionary history of Paraburkholderia’s symbiotic relationships may be
general within Dictyostelium hosts, but not so general that it can
associate with hosts of other genera.  Our work further develops
a emerging model system for the study of symbiosis in microbes.