“…The study of archaeal defense mechanisms has been more limited, with only surface resistance (Deng et al, 2014;Rowland et al, 2020), argonaute (Lee et al, 2021;Wang et al, 2009;Zander et al, 2017;Zeng et al, 2022), restriction-modification (Gulati et al, 2023;Ouellette et al, 2018;Zatopek et al, 2021) and diverse CRISPR-Cas (Makarova et al, 2020;Shah et al, 2019;Zink et al, 2020) characterized so far. Moreover, despite the near ubiquity of CRISPR-Cas systems in archaea, only four Acrs have been experimentally identified in archaeal viruses, in contrast to more than 100 Acrs identified in bacteriophages (Bondy-Denomy et al, 2018;Lin et al, 2023;Peng et al, 2020).…”