In the study published in the journal SCIENCE CHINA Life Sciences on May 6, entitled Virome in Marine Ecosystems Reveal Remarkable Invertebrate RNA virus Diversity, Prof. CUI Jie’s group at the Institut Pasteur of Shanghai of the Chinese Academy of Sciences reported 363 RNA viruses or partial genomes in 58 samples of marine invertebrates, and among which 315 RNA viruses or partial genomes were new since they only showed limited similarity to any recorded RNA virus in the public database.
The oceans are rich of various kinds of resources which have great exploitation potential and are far away from fully understood. However, the virus-related marine biosafety issues deserve great attention. There are not only many animal and plant species undiscovered, but also a much larger and diverse number of microorganisms such as viruses. Traditional studies of marine viruses have focused on bacteriophage represented DNA viruses, and little is known about the genetic diversity, distribution characteristics and transmission patterns of RNA viruses characterized with higher substitution rate and more unstable genome.
The overall characterization of virus distribution (Image by IPS). The distribution and diversity of virus in invertebrate transcriptomes. The top graph shows the number of reads in each library. The colors of the bars indicate the location of sample collecting, Yellow Sea (yellow), East China Sea (red), South China Sea (blue). The full name of each library is shown on top of each bar, while major host classifications are shown above the bar graph. The bottom graph shows a summary of classification of virus species found in this study.
Here, CUI Jie’s team have collected a total of 58 marine invertebrate samples from 3 phyla and 6 classes and studied their RNA viromes with the approach of meta-transcriptomics sequencing. By using improved bioinformatic pipelines, the team have identified 363 RNA viruses covering nine virus families (Durnavirales, Totiviridae, Bunyavirales, Chuviridae, Picornavirales, Flaviviridae, Hepelivirales, Solemoviridae, and Tombusviridae). Among them, 315 RNA viruses are sufficiently divergent to the already documented RNA viruses, greatly expanded the collection of marine invertebrate viruses. The team also reported 3 marine invertebrate hantaviruses that are more ancient than vertebrate Hantavirus from the land, further supporting the possibility that hantaviruses have a marine origin. With a combination of genomic structure and statistical analysis, the team demonstrated a high genetic diversity of marine RNA viruses and viral genome elasticity, and revealed possible virus transmission in different ocean areas and among different invertebrate species. Overall, this study provided important insights and perspectives on the origin, evolution and transmission of marine RNA viruses by revealing marine invertebrate RNA virosphere.
Link of Article: http://engine.scichina.com/doi/10.1007/s11427-020-1936-2
Link of CAS: https://english.cas.cn/newsroom/research_news/life/202105/t20210518_269806.shtml
