Metagenomic analysis of viral communities in Baikal sponges

Abstract

Sponges are the oldest multicellular invertebrates that represent complex symbioses in aquatic ecosystems. The community of sponges includes various microorganisms: fungi, dinoflagellates, algae, archaea, bacteria, and viruses. The biodiversity and the role of viruses in sponges are poorly studied. The relevance of research in this area is also related to the worldwide problem of sponge diseases. The aim of this study was to elucidate the genetic diversity of viruses in the associated communities of the Baikal endemic sponges Baikalospongia bacillifera and Lubomirskia baikalensis (sick and visually healthy) using the metagenomic approach. We have shown a high taxonomic and functional diversity of DNA viruses in the Baikal sponge communities. Identified sequences belong to the different viral families infecting a wide range of organisms. Viral communities of visually healthy and sick Baikal sponges differed significantly, indicating the changes in the structure of microbial communities of affected sponges.