Tigriopus californicus

Copepods

We have investigated the complete enzymatic complement involved in the ω3 long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis in Tigriopus californicus, an intertidal harpacticoid copepod. Two methyl-end desaturases, five front-end desaturases and six elongases have been successfully isolated and functionally characterised. The T. californicus ωx desaturases enable the de novo biosynthesis of C₁₈ PUFA such as linoleic and α-linolenic acids, as well as several ω3 LC-PUFA from ω6 substrates. Functions demonstrated in front-end desaturases and fatty acyl elongases unveil various routes through which T. californicus can biosynthesise the physiologically important arachidonic acid (20:4ω6) and eicosapentaenoic acid (20:5ω3). Moreover, T. californicus possess a Δ4 desaturase, enabling the biosynthesis of docosahexaenoic acid (22:6ω3) via the “Δ4 pathway”.

Harpacticoid copepods such as T. californicus have complete n–3 LC-PUFA biosynthetic pathways and such capacity illustrates major roles of these invertebrates in provision of essential fatty acids to upper trophic levels.

The complete enzymatic complement involved in the n–3 LC-PUFA biosynthesis in Tigriopus californicus, an intertidal harpacticoid copepod, has been investigated. A total of two methyl-end desaturases, five front-end desaturases and six elongases have been successfully isolated and functionally characterized. The T. californicus ωx desaturases enable the de novo biosynthesis of C₁₈ PUFA such as linoleic and α-linolenic acids, as well as several n–3 LC-PUFA from n–6 substrates. Functions demonstrated in front-end desaturases and fatty acyl elongases unveil various routes through which T. californicus can biosynthesize the physiologically important arachidonic (ARA) and eicosapentaenoic (EPA) acids. Moreover, T. californicus possess a Δ4 desaturase, enabling the biosynthesis of docosahexaenoic acid (DHA) via the “Δ4 pathway”.

https://royalsocietypublishing.org/doi/full/10.1098/rsob.200402