EvoNEUROMUSCLE · Unravelling the evolutionary origin, architecture, development and regulation of neuromuscular systems

Muscles and neurons are a major hallmark of animals and given their impact on the organisms motility, the emergence of an interacting neuro-muscular system has tremendously shaped the evolution of animal body plans and behavioral repertoire. Neurons and muscle cells closely interact and likely have co-evolved. Yet, the evolutionary origin of different neuronal and muscular cell types remains elusive, mainly due to a lack of thorough studies in basal metazoans. In this project, I aim to unravel the evolutionary origin, architecture, regulation and systemic properties of the neuro-muscular system by a broad comparative approach among non-bilaterians, and by a deeper functional dissection in two model cnidarians, the sea anemone Nematostella vectensis and the hydrozoan Clytia hemisphaerica. By comparing single cell transcriptomes, we will reveal common or distinct molecular profiles of neurons and muscles in early branching, non-bilaterian species (i.e. Porifera, Ctenophora, Cnidaria) and bilaterians (i.e. all other animals), allowing us to identify ancestral versus independently evolved neuro-muscular modules comprised of specifically interacting cells. We will then use genome editing, transgenics and newly developed functional tools to unravel the architecture of the cnidarian neuro-muscular system on single cell resolution, the function of specific neuronal and muscle populations, their plasticity and regenerative capacity. We hypothesize to identify common cellular network modules allowing for fast and slow neuro-muscular regulation in bilaterians and non-bilaterians, which may be ancestral or convergently evolved in different animal lineages. The expected outcome will impact our understanding of the evolution of organisms with complex body plans.