Genome of sea anemone Exaiptasia pallida and microRNA-messenger RNA interactome of tentacle regeneration

Cnidarians including sea anemones, corals, hydra, and jellyfishes are a group of animals well known for their regeneration capacity. However, how noncoding RNAs such as microRNAs contribute to the mechanisms underlying in their tissue regeneration in is poorly understood. Here, we sequenced and assembled the genome of a sea anemone<i> Exaiptasia</i> <i>pallida </i>collected in Hong Kong waters. The assembled genome size of <i>E. pallida </i>is 229.21 Mb with a scaffold N50 of 10.58 Mb and BUSCO completeness at 88.2 %. Tenacles of <i>E. pallida </i>were excised and cultured at three temperatures (17<b>°</b>C, 22<b>°</b>C, and 27<b>°</b>C). While tentacles regeneration was slowest for animals cultured at 17 <b>°</b>C, they also experienced highest regeneration and lowest mortality rates. Both mRNA and microRNA were also sequenced at 9 timepoints from regenerating tentacles at 22<b>°</b>C , including 0 hours, 6 hours, 12 hours, 18 hours, 1 day, 2 days, 3 days, 6 days, and 8 days. Based on expression profiles and binding energy, 11 pairs of microRNA:mRNA were predicted to participate during tentacle regeneration. Among them, 3 pairs were also validated by luciferase reporter assays, including miR-2037:TFAP2E, miR-2037:RBCK1, and a novel microRNA Sc6vya5_7176_790104:RBCK1. The established sea anemone model will be useful for further investigation of cnidarian biology, evolution, and effect under climate change.