Animal host control of beneficial bacteria

What keeps non-pathogenic microorganisms at bay? Despite our genome-based understanding of the metabolic capacities of microbial symbionts is steadily increasing, little is known about how the host controls and confines them. All the same, it is primal to know how the symbiont manipulates host physiology to stably associate with it. Invertebrates, the microbiome plays a fundamental role in the bidirectional axis that integrates the gut and central nervous system activities, but the mechanisms responsible for microbiota-nervous system interactions are largely unknown. Marine nematode-bacterium associations are exquisitly specific, i.e. only one bacterial species can associate to the surface of one nematode species. Additionally, the symbiont spatial organization on the host surface is exact and faithfully maintained throughout host and symbiont generations via epidermal glandular sensory organs.

In this research we want to understand (1) how the animal immune and nervous systems control the identity, number and spatial distribution of their beneficial bacteria and (2) what is the ecological and evolutionary significance of specific symbiosis “outfits” (i.e. bacterial coat architectures). We will address these questions by comparing transcriptomes of symbiotic vs non-symbiotic tissues, as well as those of four selected host species. Moreover, we will compare the transcriptomes and proteomes of the four corresponding symbionts. Upon employment of omics techniques, we will analyze the function of selected molecules such as host immune effectors and neuropeptides, or symbiont secretion systems. Moreover, omics data will be employed to predict host - symbiont molecular exchange via metabolic modeling.

Duration: 05.05.2016-04.05.2021

Funding agency: Austrian Science Fund (FWF)

Project leader: Dr. Silvia Bulgheresi

Participants: Silvia Bulgheresi, Jean-Marie Volland, Lena König, Tobias Viehböck, Friedrich Mössel