Functionally diverse front-end desaturases are widespread in the phylum Annelida

Marc Ramos-Llorens, Francisco Hontoria, Juan Navarro, David Ellard Keith Ferrier, Oscar Monroig*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Downloads (Pure)


Aquatic single-cell organisms have long been believed to be unique primary producers of omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA). Multiple invertebrates including annelids have been discovered to possess methyl-end desaturases enabling key steps in the de novo synthesis of ω3 LC-PUFA, and thus potentially contributing to their production in the ocean. Along methyl-end desaturases, the repertoire and function of further LC-PUFA biosynthesising enzymes is largely missing in Annelida. In this study we examined the front-end desaturase gene repertoire across the phylum Annelida, from Polychaeta and Clitellata, major classes of annelids comprising most annelid diversity. We further characterised the functions of the encoded enzymes in selected representative species by using a heterologous expression system based in yeast, demonstrating that functions of Annelida front-end desaturases have highly diversified during their expansion in both terrestrial and aquatic ecosystems. We concluded that annelids possess at least two front-end desaturases with Δ5 and Δ6Δ8 desaturase regioselectivities, enabling all the desaturation reactions required to convert the C18 precursors into the physiologically relevant LC-PUFA such as eicosapentaenoic and arachidonic acids, but not docosahexaenoic acid. Such a gene complement is conserved across the different taxonomic groups within Annelida.
Original languageEnglish
Article number159377
Number of pages10
JournalBiochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
Issue number10
Early online date29 Jul 2023
Publication statusPublished - 1 Oct 2023


  • Annelida
  • Biosynthesis
  • Front-end desaturases
  • Functional diversity
  • Long-chain polyunsaturated fatty acids


Dive into the research topics of 'Functionally diverse front-end desaturases are widespread in the phylum Annelida'. Together they form a unique fingerprint.

Cite this