Abstract

Although calcareous anatomical structures have evolved in diverse animal groups, such structures have been unknown in insects. Here, we report the discovery of high-magnesium calcite [CaMg(CO3)2] armor overlaying the exoskeletons of major workers of the leaf-cutter ant Acromyrmex echinatior. Live-rearing and in vitro synthesis experiments indicate that the biomineral layer accumulates rapidly as ant workers mature, that the layer is continuously distributed, covering nearly the entire integument, and that the ant epicuticle catalyzes biomineral nucleation and growth. In situ nanoindentation demonstrates that the biomineral layer significantly hardens the exoskeleton. Increased survival of ant workers with biomineralized exoskeletons during aggressive encounters with other ants and reduced infection by entomopathogenic fungi demonstrate the protective role of the biomineral layer. The discovery of biogenic high-magnesium calcite in the relatively well-studied leaf-cutting ants suggests that calcareous biominerals enriched in magnesium may be more common in metazoans than previously recognized.

Biomineral armour is known in a number of diverse creatures but has not previously been observed in insects. Here, the authors report on the discovery and characterization of high-magnesium calcite armour which overlays the exoskeletons of leaf-cutter ants.

Details

Title
Biomineral armor in leaf-cutter ants
Author
Li, Hongjie 1   VIAFID ORCID Logo  ; Chang-Yu, Sun 2 ; Fang Yihang 3   VIAFID ORCID Logo  ; Carlson, Caitlin M 4 ; Xu, Huifang 3   VIAFID ORCID Logo  ; Ješovnik Ana 5   VIAFID ORCID Logo  ; Sosa-Calvo, Jeffrey 6   VIAFID ORCID Logo  ; Zarnowski, Robert 7   VIAFID ORCID Logo  ; Bechtel, Hans A 8 ; Fournelle, John H 3 ; Andes, David R 7 ; Schultz, Ted R 5 ; Gilbert Pupa U P A 9   VIAFID ORCID Logo  ; Currie, Cameron R 10   VIAFID ORCID Logo 

 University of Wisconsin-Madison, Department of Bacteriology, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675); Wisconsin Energy Institute, University of Wisconsin-Madison, Department of Energy Great Lakes Bioenergy Research Center, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675); State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of Ministry of Agriculture and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China (GRID:grid.203507.3) (ISNI:0000 0000 8950 5267) 
 University of Wisconsin-Madison, Department of Physics, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675) 
 University of Wisconsin-Madison, Department of Geoscience, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675) 
 University of Wisconsin-Madison, Department of Bacteriology, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675) 
 National Museum of Natural History, Smithsonian Institution, Department of Entomology, Washington, USA (GRID:grid.453560.1) (ISNI:0000 0001 2192 7591) 
 National Museum of Natural History, Smithsonian Institution, Department of Entomology, Washington, USA (GRID:grid.453560.1) (ISNI:0000 0001 2192 7591); Arizona State University, School of Life Sciences, Tempe, USA (GRID:grid.215654.1) (ISNI:0000 0001 2151 2636) 
 University of Wisconsin-Madison, Department of Medicine, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675); University of Wisconsin-Madison, Department of Medical Microbiology and Immunology, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675) 
 Lawrence Berkeley National Laboratory, Advanced Light Source Division, Berkeley, USA (GRID:grid.184769.5) (ISNI:0000 0001 2231 4551) 
 University of Wisconsin-Madison, Department of Physics, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675); University of Wisconsin-Madison, Department of Geoscience, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675); University of Wisconsin-Madison, Departments of Chemistry, Materials Science and Engineering, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675) 
10  University of Wisconsin-Madison, Department of Bacteriology, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675); Wisconsin Energy Institute, University of Wisconsin-Madison, Department of Energy Great Lakes Bioenergy Research Center, Madison, USA (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675) 
Publication year
2020
Publication date
2020
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2473250039
Copyright
© The Author(s) 2020. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.