Immune function keeps endosymbionts under control

Abstract

How does an animal host prevent intracellular symbionts getting out of hand? A new paper in BMC Biology provides evidence that the mutualism between a beetle and its bacterial endosymbiont could be mediated through the expression of host immune genes.

Figure 1

Sitophilus zeamais on seeds of corn. Image courtesy of Abdelaziz Heddi.

Figure 2

Summary of Sitophilus immune responses to its primary endosymbiont SZPE based on [6]. The left box indicates the constitutive response of bacteriocytes to the dense population of endosymbionts within it; the right box indicates the reaction of the rest of the body when bacteria 'escape' from the bacteriome into the insect's hemocele (body cavity). Not all of the genes studied in [6] are listed here.