De-novo Genome Assembly of the Edwardsiid Anthozoan Edwardsia elegans.

Cnidarians (sea anemones, corals, hydroids, and jellyfish) are a key outgroup for comparisons with bilaterial animals to trace the evolution of genomic complexity and diversity within the animal kingdom, as they separated from most other animals 100s of millions of years ago. Cnidarians have extensive diversity, yet the paucity of genomic resources limits our ability to compare genomic variation between cnidarian clades and species. Here we report the genome for Edwardsia elegans, a sea anemone in the most specious genus of the family Edwardsiidae, a phylogenetically important family of sea anemones that contains the model anemone Nematostella vectensis.

miRNA-target complementarity in cnidarians resembles its counterpart in plants.

microRNAs (miRNAs) are important post-transcriptional regulators that activate silencing mechanisms by annealing to mRNA transcripts. While plant miRNAs match their targets with nearly-full complementarity leading to mRNA cleavage, miRNAs in most animals require only a short sequence called 'seed' to inhibit target translation. Recent findings showed that miRNAs in cnidarians, early-branching metazoans, act similarly to plant miRNAs, by exhibiting full complementarity and target cleavage; however, it remained unknown if seed-based regulation was possible in cnidarians.

Candidate stem cell isolation and transplantation in Hexacorallia.

Stem cells are the foundation for cell therapy due to their ability to self-renew, differentiate into other cell types, and persist throughout the life of an organism. Stem cell isolation and transplantation have not yet been established in Hexacorallia, a cnidarian subclass containing stony corals and sea anemones. Here, we demonstrate that candidate stem cells in the hexacorallian Nematostella vectensis can be transplanted into adult animals.

A conserved fertilization complex bridges sperm and egg in vertebrates.

Fertilization, the basis for sexual reproduction, culminates in the binding and fusion of sperm and egg. Although several proteins are known to be crucial for this process in vertebrates, the molecular mechanisms remain poorly understood. Using an AlphaFold-Multimer screen, we identified the protein Tmem81 as part of a conserved trimeric sperm complex with the essential fertilization factors Izumo1 and Spaca6.