Systems Biology Programme Erik T. Frank

20/11/202312:00R_473.10_AULASystems Biology ProgrammeErik T. FrankDepartment of Animal Ecology and Tropical Biology, University of Würzburg and Department of Ecology and Evolution, University of Lausanne."Evolution of Social Wound Care in Ants: from amputations to antimicrobials"Host: Baud, AmelieAbstract:Animals developed different behavioural adaptations to help injured individuals. In ants
permanently injured individuals that lost an extremity are carried back to safety to allow them
to recover. In case of an infection, different behavioural strategies have evolved to combat the
pathogens. Ants often use the metapleural gland, but some genera lost this gland in their
evolutionary history. Here we compare two different behaviours to combat an infected wound,
one with the metapleural gland and one without. The ant Megaponera analis treats infected
wounds with antimicrobial compounds secreted from the metapleural gland, thereby reducing
mortality of infected ants by 90%. Further analyses of the metapleural gland secretions of M.
analis revealed over 121 chemical compounds and 41 proteins, almost half of which have an
antimicrobial effect. However, ants from the genus Camponotus do not have this gland at their
disposal. Remarkably, we observed that workers amputated the infected leg by biting it off at
its base. This behaviour halted the infection and guaranteed the survival of the injured ant. The
large phylogenetic distance between Megaponera and Camponotus and their strikingly
different natural history (Megaponera a group-hunting predator, Camponotus a solitary
foraging generalist) also suggest that wound care behaviour could be much more widespread in
social insects than previously thought. Overall, we reveal a multifaceted care system, which not
only allows to differentiate between sterile and infected wounds but also to treat them either
with antimicrobial compounds or amputation of the infected leg. Thereby allowing M. analis
and Camponotus to combat opportunistic pathogenic pressures present on their frequently
inflicted wounds with two very different strategies.