Diversity,evolutionary contribution and ecological roles of aquatic viruses

Aquatic viruses include infected viruses in aquatic animals, plants and microorganisms, and free-floating viruses(virioplankton)in water environments. In the last three decades, a huge number of aquatic viruses, especially diverse free-floating viruses,including cyanophages, phycoviruses, archaea viruses, giant viruses, and even virophages, have been identified by virological experiments and metagenomic analyses. Based on a comprehensive introduction of aquatic virus classification and their morphological and genetic diversity, here, we summarize and outline main virus species, their evolutionary contribution to aquatic communities through horizontal gene transfer, and their ecological roles for cyanobacterial bloom termination and global biogeochemical cycling in freshwater and marine ecosystems. Thereby, some novel insights of aquatic viruses and virus-host interactions, especially their evolutionary contribution and ecological rolesin diverse aquatic communities and ecosystems, are highlighted in this review.

Recent insights into aquatic viruses: Emerging and reemerging pathogens, molecular features, biological effects, and novel investigative approaches

Aquatic viruses are naturally present in the aquatic environment and the number of viruses is staggering.Various multicellular organisms in aquatic ecosystems may be infected,cross-species transmitted,manipulated,and killed by aquatic viruses,which can lead to cascading ecological effects.The viruses in unicellular aquatic organisms can alter interactions between host individuals,and are essential in effecting or maintaining the dynamics of aquatic microbial communities,horizontal gene transfer,biodiversity,and modulating ecological processes globally.Meanwhile,hosts also impact viral abundance and diversity.Microbial diversity drives multifunctionality in ecosystems,while viruses shape complex microbial communities and are crucial for ecosystem functioning.This review focuses on molecular,genetic,evolutionary,and ecosystemic advances related to emerging and reemerging aquatic viruses,presents the contexts,novel tools,and investigative approaches pertaining to the study of aquatic virology,and discusses the mechanisms by which viruses affect aquatic ecosystems.The paper provides an efficient and broadly-based blueprint for improving understanding of aquatic viruses.

Fish ACE2 is not susceptible to SARS-CoV-2

Dear Editor,The ongoing pandemic of coronavirus disease 2019(COVID-19)has reshaped our daily life and caused>4 million deaths worldwide(https://covid19.who.int/).Although lockdown and vaccination have improved the situation in many countries,imported cases and sporadic outbreaks pose a constant stress to the prevention and control of COVID-19.