Queen polymorphism

In the queen polymorphic ant Leptothorax ergatogyneous, queens are either winged (“gynomorphic”) or wingless (“ergatoid”). In addition to their winglessness, ergatoid queens exhibit body size and morphology intermediate between gynomorphic queens and workers. Previous work hypothesized that this intraspecific polymorphism was likely genetically regulated but the gene(s) involved were unknown. Using a combination of genomics, morphometrics, and functional assays, we have characterized the genetic basis for this queen polymorphism and the mechanism by which it induces ergatoid morphology. This work identifies the first genetic caste determination polymorphism and resolves a longstanding question in myrmecology about the evolution of novel castes like ergatoid queens. Additionally, we established Leptothorax ergatogyneous as a viable model system for the study of polymorphisms.