Conservation and turnover of miRNAs and their highly complementary targets in early branching animals

MicroRNAs (miRNAs) are crucial post-transcriptional regulators that have been extensively studied in Bilateria, a group comprising the majority of extant animals, where more than 30 conserved miRNA families identified. By contrast, bilaterian targets largely not conserved. Cnidaria is sister to Bilateria and thus provides unique opportunity for comparative studies. Strikingly, like their plant counterparts, cnidarian miRNAs shown predominantly highly complementary leading transcript cleavage by Argonaute proteins. Here, we assess conservation small RNA sequencing followed target prediction eight species Anthozoa (sea anemones corals), earliest-branching class. We uncover dozens novel but only few ones. Further, given high complementarity, were able computationally identify each species. Besides evidence specific sites, which maintained between sea stony corals across 500 Myr evolution, also find indications convergent evolution regulation different miRNAs. Our data indicate cnidarians corresponding targets, despite suggesting evolutionary turnover.