Description
Muscles were a crucial innovation in the evolution of animals. In Bilateria muscles are a main derivative of the mesoderm. Cnidaria lack this intermediate germ layer, yet they possess muscle cells deriving from endoderm and ectoderm. Studying muscles in diploblastic animals might help to understand the evolution of mesoderm and muscle. In the last decade, the sea anemone Nematostella vectensis has been established as a new model system, however little is known about the histology and ultrastructure of the animal. So far it was unclear, whether muscles in Nematostella are still epithelial, or have become mesenchymal as in bilaterians. In order to understand the epithelial organisation of muscle cells we conducted electron microscopical studies. In addition we investigated the differentiation of muscle cells during early development of the animal. We found that the shape of the cells forming the muscle system varies considerably. Besides typical epitheliomuscular cells there are highly specialised retractor muscle cells, where the connection between the apical and basal portion is reduced to a long and thin cytoplasmatic bridge. Interestingly, tentacle retractor muscle cells detach completely from the surrounding epithelial cells and become mesenchymal basiepithelial cells attached to the mesoglea. Further we demonstrate that retractor muscles cell in mesenteries, as well as in tentacles differentiate from regular epithelial cells before they alter their epithelial organisation. In this context Nematostella gives novel insights into the question, how a transition from an epithelial muscle system to a mesenchymal could have happened.Recently, we have established methods for isolating muscle-cell specific RNA of Nematostella vectensis and a scyphozoan jellyfish Aurelia aurita. Initial results of the analysis of the muscle cell transcriptomes will be presented.| Period | 2014 |
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| Event title | 5th Meeting of the European Society for Evolutionary Developmental Biology |
| Event type | Conference |
| Location | Vienna, AustriaShow on map |