Discovery, Prevalence, and Persistence of Novel Circular Single-Stranded DNA Viruses in the Ctenophores Mnemiopsis leidyi and Beroe ovata.

Mya Breitbart,Karyna Rosario,Carina Graham,Laura M Birsa,Anna Walters,Jens C Nejstgaard,Bayleigh E Benner,Sidney Fulford,Parker E Jernigan,Stella A Berger,Dawn B Goldsmith,Rachel C Harbeitner

doi:10.3389/fmicb.2015.01427

Abstract

Gelatinous zooplankton, such as ctenophores and jellyfish, are important components of marine and brackish ecosystems and play critical roles in aquatic biogeochemistry. As voracious predators of plankton, ctenophores have key positions in aquatic food webs and are often successful invaders when introduced to new areas. Gelatinous zooplankton have strong impacts on ecosystem services, particularly in coastal environments. However, little is known about the factors responsible for regulating population dynamics of gelatinous organisms, including biological interactions that may contribute to bloom demise. Ctenophores are known to contain specific bacterial communities and a variety of invertebrate parasites and symbionts; however, no previous studies have examined the presence of viruses in these organisms. Building upon recent studies demonstrating a diversity of single-stranded DNA viruses that encode a replication initiator protein (Rep) in aquatic invertebrates, this study explored the presence of circular, Rep-encoding single-stranded DNA (CRESS-DNA) viruses in the ctenophores Mnemiopsis leidyi and Beroe ovata collected from the Skidaway River Estuary and Savannah River in Georgia, USA. Using rolling circle amplification followed by restriction enzyme digestion, this study provides the first evidence of viruses in ctenophores. Investigation of four CRESS-DNA viruses over an 8-month period using PCR demonstrated temporal trends in viral prevalence and indicated that some of the viruses may persist in ctenophore populations throughout the year. Although future work needs to examine the ecological roles of these ctenophore-associated viruses, this study indicates that viral infection may play a role in population dynamics of gelatinous zooplankton.

Highlights

Gelatinous zooplankton, including ctenophores and jellyfish, play critical roles in marine ecosystems (Mills, 1995; Schneider and Behrends, 1998; Brodeur et al, 2002)
Building upon recent studies demonstrating a diversity of single-stranded DNA viruses encoding a replication initiator protein (Rep) in a wide variety of aquatic invertebrates (Dunlap et al, 2013; Hewson et al, 2013a,b; Ng et al, 2013; Pham et al, 2014; Soffer et al, 2014; Dayaram et al, 2015; Fahsbender et al, 2015; Rosario et al, 2015), this study explored the presence of circular, Rep-encoding single-stranded DNA (CRESS-DNA) viruses in the ctenophores M. leidyi and B. ovata collected from the Skidaway River Estuary and Savannah River in coastal Georgia, USA
Future work needs to examine the ecological roles of these ctenophore-associated viruses, this study indicates that viral infection may be an important factor to consider when examining bloom dynamics of gelatinous zooplankton

Summary

Introduction

Gelatinous zooplankton, including ctenophores and jellyfish, play critical roles in marine ecosystems (Mills, 1995; Schneider and Behrends, 1998; Brodeur et al, 2002). Ctenophore specimens were used for discovery of CRESS-DNA viruses following a protocol previously described for marine invertebrates (Rosario et al, 2015). Following recent studies that have discovered a diversity of CRESS-DNA viruses in marine invertebrates, this study surveyed the presence of this viral group in ctenophores.

Results

Conclusion