Detection of Injury‐Associated Protein Using a MIF Antibody in <i>Physarum polycephalum</i> and <i>Badhamia utricularis</i>

Myxomycetes are remarkable organisms, capable of strikingly complex behaviors and exceptional wound healing, yet the molecular mechanisms underlying their immunity and regenerative capacities remain largely unexplored. In this study, we provide the first evidence that these unique organisms could possess a protein resembling macrophage migration inhibitory factor (MIF). Using a custom MIF polyclonal antibody, we detected signals specifically along the pseudopodia of two myxomycetes species, Physarum polycephalum and Badhamia utricularis. Western blot analysis revealed three distinct bands consistent with potential monomeric, dimeric, and trimeric forms of the protein. Notably, following mechanical injury, this protein accumulated at the sites of damage, suggesting a potential role in injury sensing and tissue repair. In contrast, exposure to GFP-expressing Erwinia carotovora did not alter its localization, indicating that this response is likely independent of non-self-recognition. Although current genomic resources for these myxomycetes do not contain annotated MIF sequences, our findings highlight a previously unrecognized, injury-responsive protein in these organisms. This discovery underscores the sophisticated regenerative capacities of myxomycetes and opens new avenues for exploring immune and repair mechanisms in this ancient and fascinating species.