Among the many unexpected findings ranging from genome architecture, development, non-coding RNAs, to evolution that the team has identified, the presence of genes encoding sesquiterpenoid hormones, which are typically found in insects to regulate metamorphosis in arthropods, in jellyfish is one of the most surprising. The discovery helps scientist to understand how jellyfish undergo the transition between developmental stages and the change of reproduction method during their lifecycle which also comprises metamorphosis.
Another remarkable finding is the distinct homeobox genes organisation. Most of the homeobox genes, which are important development regulators for the formation of three germ layers in bilaterians like humans, are also found in cnidarians like two-germ layers jellyfish. This showed that cnidarians and bilaterians have undergone divergent pathways since their extinct cnidarian-bilaterian ancestor.
The findings, recently published in top scientific journal Nature Communications, increase our understanding of the ecological roles and reproduction mechanism of jellyfish, and give insight into the genomic characters of their ancestor.
Nong, W., Cao, J., Li, Y., Qu, Z., Sun, J., Swale, T., ... & Bendena, W. (2020). Jellyfish genomes reveal distinct homeobox gene clusters and conservation of small RNA processing. Nature communications, 11(1), 1-11. DOI: https://doi.org/10.1038/s41467-020-16801-9