| Autor: |
Walker AA; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.; Centre of Excellence for Innovations in Protein and Peptide Science, The University of Queensland, Brisbane, QLD 4072, Australia., Robinson SD; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia., Merritt DJ; School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia., Cardoso FC; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.; Centre of Excellence for Innovations in Protein and Peptide Science, The University of Queensland, Brisbane, QLD 4072, Australia., Goudarzi MH; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.; Centre of Excellence for Innovations in Protein and Peptide Science, The University of Queensland, Brisbane, QLD 4072, Australia., Mercedes RS; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.; Centre of Excellence for Innovations in Protein and Peptide Science, The University of Queensland, Brisbane, QLD 4072, Australia., Eagles DA; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.; Centre of Excellence for Innovations in Protein and Peptide Science, The University of Queensland, Brisbane, QLD 4072, Australia., Cooper P; Research School of Biology, Australian National University, Canberra, ACT 2601, Australia., Zdenek CN; Venom Evolution Lab, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia., Fry BG; Venom Evolution Lab, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia., Hall DW; Entomology and Nematology Department, University of Florida, Gainesville, FL 32608., Vetter I; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.; School of Pharmacy, The University of Queensland, Brisbane, QLD 4102, Australia., King GF; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.; Centre of Excellence for Innovations in Protein and Peptide Science, The University of Queensland, Brisbane, QLD 4072, Australia. |
| Abstrakt: |
Larvae of the genus Megalopyge (Lepidoptera: Zygaenoidea: Megalopygidae), known as asp or puss caterpillars, produce defensive venoms that cause severe pain. Here, we present the anatomy, chemistry, and mode of action of the venom systems of caterpillars of two megalopygid species, the Southern flannel moth Megalopyge opercularis and the black-waved flannel moth Megalopyge crispata . We show that megalopygid venom is produced in secretory cells that lie beneath the cuticle and are connected to the venom spines by canals. Megalopygid venoms consist of large aerolysin-like pore-forming toxins, which we have named megalysins, and a small number of peptides. The venom system differs markedly from those of previously studied venomous zygaenoids of the family Limacodidae, suggestive of an independent origin. Megalopygid venom potently activates mammalian sensory neurons via membrane permeabilization and induces sustained spontaneous pain behavior and paw swelling in mice. These bioactivities are ablated by treatment with heat, organic solvents, or proteases, indicating that they are mediated by larger proteins such as the megalysins. We show that the megalysins were recruited as venom toxins in the Megalopygidae following horizontal transfer of genes from bacteria to the ancestors of ditrysian Lepidoptera. Megalopygids have recruited aerolysin-like proteins as venom toxins convergently with centipedes, cnidarians, and fish. This study highlights the role of horizontal gene transfer in venom evolution. |
