Symbiont Acquisition and Replacement as a Source of Ecological Innovation.
Nutritional symbionts play a major role in the ecology and evolution of insects. The recent accumulation of knowledge on the identity, function, genomics, and phylogenetic relationships of insect-bacteria symbioses provides the opportunity to assess the effects of symbiont acquisitions and replacements on the shift into novel ecological niches and subsequent lineage diversification. The megadiverse insect order Hemiptera presents a particularly large diversity of symbiotic associations that has frequently undergone shifts in symbiont localization and identity, which have contributed to the exploitation of nutritionally imbalanced diets such as plant saps or vertebrate blood. Here we review the known ecological and evolutionary implications of symbiont gains, switches, and replacements, and identify future research directions that can contribute to a more comprehensive understanding of symbiosis as a major driving force of ecological adaptation.
Insect Symbiosis Research Group, Max Planck Institute for Chemical Ecology, Jena, Germany; Present address: Systems Biology, Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA. Electronic address: ssudakaran@discovery.wisc.edu.
Sailendharan
S
Sudakaran
Experimental Ecology and Evolution Research Group, Max Planck Institute for Chemical Ecology, Jena, Germany; Institute of Microbiology, Friedrich Schiller University, Jena, Germany; Present address: Department of Ecology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany.
Christian
C
Kost
Insect Symbiosis Research Group, Max Planck Institute for Chemical Ecology, Jena, Germany; Department for Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany. Electronic address: mkaltenpoth@uni-mainz.de.
Martin
M
Kaltenpoth
D000222:Adaptation, Physiological; D000818:Animals; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D005075:Biological Evolution; D019143:Evolution, Molecular; D000069196:Gastrointestinal Microbiome; D016680:Genome, Bacterial; D023281:Genomics; D006430:Hemiptera / Q000235:genetics / Q000382:microbiology* / Q000502:physiology*; D064307:Microbiota; D010802:Phylogeny; D013559:Symbiosis
coevolution; ecological niche; gut microbiota; insect symbiosis; intracellular symbiont; mutualism