Jennifer J. Wernegreen

TL;DR: Recent technological and intellectual advances that have changed thinking about five questions about how have bacteria facilitated the origin and evolution of animals; how do animals and bacteria affect each other’s genomes; how does normal animal development depend on bacterial partners; and how is homeostasis maintained between animals and their symbionts are highlighted.

TL;DR: Comparison of two fully sequenced genomes of Buchnera aphidicola reveals the most extreme genome stability to date: no chromosome rearrangements or gene acquisitions have occurred in the past 50 to 70 million years, despite substantial sequence evolution and the inactivation and loss of individual genes.

TL;DR: The full genome sequences of two obligate mutualists, Buchnera aphidicola of aphids and Wigglesworthia glossinidia of tsetse flies, reveal substantial gene loss and an integration of host and symbiont metabolic functions.

TL;DR: A large number of pathogens and mutualistic symbionts retain loci that underlie their unique interaction types, such as genes enabling nutrient provisioning by mutualistic bacteria-inhabiting animals.

TL;DR: Analysis of phylogenies of Buchnera and Uroleucon supports the interpretation that symbionts and aphids have undergone strict cospeciation, with no horizontal transmission of symbiotic bacteria even among closely related, ecologically similar aphid hosts.