Morphological characterization of virus-like particles in coral reef sponges

Cecília Pascelli; Patrick W Laffy; Marija Kupresanin; Timothy Ravasi; Nicole S Webster

doi:10.7717/peerj.5625

Morphological characterization of virus-like particles in coral reef sponges

PeerJ. 2018 Oct 17:6:e5625. doi: 10.7717/peerj.5625. eCollection 2018.

Authors

Cecília Pascelli^{1

2

3}, Patrick W Laffy¹, Marija Kupresanin⁴, Timothy Ravasi⁴, Nicole S Webster^{1

3

5}

Affiliations

¹ Australian Institute of Marine Science, Townsville, Queensland, Australia.
² James Cook University, Townsville, Queensland, Australia.
³ AIMS@JCU, Australian Institute of Marine Science and James Cook University, Townsville, Queensland, Australia.
⁴ KAUST Environmental Epigenetic Program (KEEP), Division of Biological and Environmental Sciences & Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.
⁵ Australian Centre for Ecogenomics, University of Queensland, Brisbane, Queensland, Australia.

Abstract

Marine sponges host complex microbial consortia that vary in their abundance, diversity and stability amongst host species. While our understanding of sponge-microbe interactions has dramatically increased over the past decade, little is known about how sponges and their microbial symbionts interact with viruses, the most abundant entities in the ocean. In this study, we employed three transmission electron microscopy (TEM) preparation methods to provide the first comprehensive morphological assessment of sponge-associated viruses. The combined approaches revealed 50 different morphologies of viral-like particles (VLPs) represented across the different sponge species. VLPs were visualized within sponge cells, within the sponge extracellular mesohyl matrix, on the sponge ectoderm and within sponge-associated microbes. Non-enveloped, non-tailed icosahedral VLPs were the most commonly observed morphotypes, although tailed bacteriophage, brick-shaped, geminate and filamentous VLPs were also detected. Visualization of sponge-associated viruses using TEM has confirmed that sponges harbor not only diverse communities of microorganisms but also diverse communities of viruses.

Keywords: GBR; Great Barrier Reef; Marine sponges; Red Sea; TEM; Transmission Electron Microscopy; VLP; Virus.

Grants and funding

Nicole S. Webster was funded through an Australian Research Council Future Fellowship FT120100480 and Cecília Pascelli was funded through a PhD Scholarship from The CAPES Foundation and Science without Borders. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.