Recently, a study led by Prof. Li Meng’s group from Shenzhen University, in collaboration with researchers from the Hong Kong University of Science and Technology, the Institute Pasteur, and the National Center for Biotechnology Information, was published in ISME Communications. This study sheds light on the diversity of Bathyarchaeia viruses and their unique features, including the virus-encoded CRISPR system components. The findings, presented by an international team of scientists, provide valuable insights into the world of Bathyarchaeia and their intricate interactions with viral counterparts.

Bathyarchaeia, a class of archaea commonly found in sedimentary ecosystems, has long captivated scientists due to its prevalence and abundance in marine and freshwater sediments. By analyzing metagenomic data from various environments, Dr. Li’s team identified 56 genomes of Bathyarchaeia viruses. Through gene sharing network and phylogenomic analyses, they proposed four new virus families, including viruses from the realms Duplodnaviria and Adnaviria, as well as archaea-specific spindle-shaped viruses. One of the remarkable findings of the study was the presence of diverse CRISPR elements within these Bathyarchaeia viruses. The family "Fuxiviridae" was found to harbor an atypical Type IV-B CRISPR-Cas system and a Cas4 protein that may interfere with host immunity. Moreover, viruses of the family "Chiyouviridae" were found to encode a Cas2-like endonuclease and two mini-CRISPR arrays, hinting at their potential to manipulate the host CRISPR system for their own benefit. These discoveries not only deepen our understanding of Bathyarchaeia viruses but also shed light on the intricate interactions between these viruses and their hosts.

This work was supported byNational Key Research and Development Program of China (2022YFA0912200), the National Natural Science Foundation of China (32225003, 92251306, 31970105), the Innovation Team Project of Universities in Guangdong Province (No. 2020KCXTD023), the Shenzhen Science and Technology Program (JCYJ20200109105010363), and Shenzhen University 2035 Program for Excellent Research (2022B002).

Link to the article:https://doi.org/10.1093/ismeco/ycad011

Figure 1 Distribution of identified viruses across the evolutionary tree of the Bathyarchaeia.