Photo of John McCutcheon

John McCutcheon Genome biologist

John McCutcheon’s lab studies the diverse collections of microorganisms that are associated with insects, with a particular focus on interactions that are intimate and stable across evolutionary time. He is ultimately interested in the evolutionary forces that establish and maintain associations between organisms.

Most of his group studies the symbioses between sap-feeding insects and their intracellular bacterial symbionts. These symbioses rival organelle-host relationships in terms of cellular complexity and organismal integration, and this intimacy is reflected in the highly degenerate nature of the bacterial symbiont genomes. Indeed, all of the smallest bacterial genomes reported yet are from intracellular symbionts of sap-feeding insects. Because these symbionts cannot be cultured outside of their host insect, the McCutcheon lab relies heavily on comparative genomic and transcriptomic methods to study these systems. Much of the lab’s current focus is on understanding the role of the insect host, as well as any co-symbionts, in the functioning of bacterial symbionts with the most degenerate genomes.

Relevant Publications

P.J. Keeling et al, "Symbiosis becoming permanent: survival of the luckiest," Proceedings of the National Academy of Sciences USA 112, pp. 10101-10103, 2015.

M.A. Campbell et al, "Genome expansion via lineage splitting and genome reduction in the cicada endosymbiont Hodgkinia," Proceedings of the National Academy of Sciences USA 112, pp. 10192-10199, 2015.

J.T. Van Leuven et al, "Sympatric speciation in a bacterial endosymbiont results in two genomes with the functionality of one," Cell, vol. 158, no. 6, pp. 1270-1280, 2014.

J.P. McCutcheon and P.J. Keeling, "Endosymbiosis: Protein targeting further erodes the organelle/symbiont distinction," Curr. Biol., vol. 24, no. 14, pp. R654–R655, 2014.

F. Husnik et al, "Horizontal gene transfer from diverse bacteria to an insect genome enables a tripartite nested mealybug symbiosis," Cell, vol. 153, no. 7, pp. 1567–1578, 2013.



Fellow Integrated Microbial Biodiversity


University of MontanaDivision of Biological Sciences


PhD (Computational Biology) Washington University

MS (Human Genetics) University of Utah

BS (Biochemistry) University of Wisconsin


United States

Ideas Related to John McCutcheon

Integrated Microbial Biodiversity | News

Symbiosis turns messy in 13-year cicadas

Bacteria that live in the guts of cicadas have split into many separate but interdependent species in a strange evolutionary...

Integrated Microbial Biodiversity | News

Non-adaptive evolution in a cicada’s gut

Organisms in a symbiotic relationship will often shed genes as they come to rely on the other organism for crucial...