Migration in the social stage of Dictyostelium discoideum amoebae impacts competition
Copyright 2014 Jack et al. Distributed under Creative Commons CC-By 4.0. This is Version 3.0. Original article with supplementary material, peer review history, any future revisions, etc. available at: Jack CN, Buttery N, Adu-Oppong B, Powers M, Thompson CRL, Queller DC, Strassmann JE. (2015) Migration in the social stage of Dictyostelium discoideum amoebae impacts competition. PeerJ 3:e1352 https://dx.doi.org/10.7717/peerj.1352
Interaction conditions can change the balance of cooperation and conflict in multicellular groups. After aggregating together, cells of the social amoeba Dictyostelium discoideum may migrate as a group (known as a slug) to a new location. We consider this migration stage as an arena for social competition and conflict because the cells in the slug may not be from a genetically homogeneous population. In this study, we examined the interplay of two seemingly diametric actions, the solitary action of kin recognition and the collective action of slug migration in D. discoideum, to more fully understand the effects of social competition on fitness over the entire lifecycle. We compare slugs composed of either genetically homogenous or heterogeneous cells that have migrated or remained stationary in the social stage of the social amoeba Dictyostelium discoideum. After migration of chimeric slugs, we found that facultative cheating is reduced, where facultative cheating is defined as greater contribution to spore relative to stalk than found for that clone in the clonal state. In addition our results support previous findings that competitive interactions in chimeras diminish slug migration distance. Furthermore, fruiting bodies have shorter stalks after migration, even accounting for cell numbers at that time. Taken together, these results show that migration can alleviate the conflict of interests in heterogeneous slugs. It aligns their interest in finding a more advantageous place for dispersal, where shorter stalks suffice, which leads to a decrease in cheating behavior.