An alternative pathway to eusociality: Exploring the molecular and functional basis of fortress defense |
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| Authors: | Sarah P. Lawson Leah T. Sigle Abigail L. Lind Andrew W. Legan Jessica N. Mezzanotte Hans‐Willi Honegger Patrick Abbot |
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| Affiliation: | 1. Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee;2. Department of Biological Sciences, University of New Hampshire, Durham, New Hampshire;3. Department of Biomedical Informatics, School of Medicine, Vanderbilt University, Nashville, Tennessee;4. Department of Neurobiology and Behavior, Cornell University, Ithaca, New York;5. Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, Kentucky |
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| Abstract: | Some animals express a form of eusociality known as “fortress defense,” in which defense rather than brood care is the primary social act. Aphids are small plant‐feeding insects, but like termites, some species express division of labor and castes of aggressive juvenile “soldiers.” What is the functional basis of fortress defense eusociality in aphids? Previous work showed that the acquisition of venoms might be a key innovation in aphid social evolution. We show that the lethality of aphid soldiers derives in part from the induction of exaggerated immune responses in insects they attack. Comparisons between closely related social and nonsocial species identified a number of secreted effector molecules that are candidates for immune modulation, including a convergently recruited protease described in unrelated aphid species with venom‐like functions. These results suggest that aphids are capable of antagonizing conserved features of the insect immune response, and provide new insights into the mechanisms underlying the evolution of fortress defense eusociality in aphids. |
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| Keywords: | Aphids eusociality fortress defense immunity Pemphigus obesinymphae
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