O. R. Collins showed that the slime mold Didymium iridis had two strains (+ and −) of cells, equivalent to gametes, that these could form immortal cell lines in culture, and that the system was controlled by alleles of a single gene. This made the species a model organism for exploring incompatibility, asexual reproduction, and mating types.
O. r. collinS shoWed that THe slImE mOLd DidYmium iRidis Had two StRaiNS (+ and −) of cELls, equivAleNT to gAMetEs, that THese coUld FoRm immoRtAl celL lineS in CuLture, aNd ThAT The systEm WaS conTrolLeD by allEles oF a sIngle GeNe. this mAdE thE sPeCieS A modEl OrgANIsM for expLoring INCOmpatibIlIty, aseXuAl ReProductiOn, anD MatIng tyPes.