All the microbiology nematodes can teach us

Abstract

One sentence summary: Nematode-bacterium associations are major research subjects. Complementing genetic studies with ecological ones is necessary to boost our understanding of how microbial symbioses evolved and how they impact the environment. Editor: Gerard Muyzer ABSTRACTBe it their pervasiveness, experimental tractability or their impact on human health and agriculture, nematode-bacterium associations are far-reaching research subjects. Although the omics hype did not spare them and helped reveal mechanisms of communication and exchange between the associated partners, a huge amount of knowledge still awaits to be harvested from their study. Here, I summarize and compare the kind of research that has been already performed on the model nematode Caenorhabditis elegans and on symbiotic nematodes, both marine and entomopathogenic ones. The emerging picture highlights how complementing genetic studies with ecological ones (in the case of well-established genetic model systems such as C. elegans) and vice versa (in the case of the yet uncultured Stilbonematinae) will deepen our understanding of how microbial symbioses evolved and how they impact our environment.

The bacterial community associated with the sheep gastrointestinal nematode parasite Haemonchus contortus

“…Most symbionts of nematodes are likely to be associated with either the gut or external surfaces and to be commensals or mutualists contributing principally to host metabolism. There is an interesting nutritional symbiosis between bacteria and the gutless stilbonematid marine worms, which obtain nutrition from external lawns of densely packed ectosymbiotic bacteria, in many cases a species-specific monoculture [ 4 – 7 ]. The focus of many studies of the microbiome of Caenorhabditis elegans has been differentiating those species which constitute a food source or are mutualists from species which are potential pathogens of either the nematode or other organisms for which the nematode acts as a vector of the bacteria [ 8 – 12 ].…”