Skip to main content

Biosynthesis of Polyunsaturated Fatty Acids—‘Many Can, Some Can’t’

  • Chapter
  • First Online:
Aquatic Animal Nutrition

Abstract

Omega-3 (ω3) long-chain polyunsaturated fatty acids (LC-PUFA) are well-known essential nutrients for vertebrates. A recent study identifies a high number of ωx desaturase sequences in a variety of invertebrates; consequently, the long-term consensus that solely marine microbes account for the ω3 LC-PUFA production has to be revised by accepting that numerous abundant invertebrates have the autochthonous capacity to make significant contributions. Even many fish species appear capable of producing even DHA; it deserves further research of why the endogenous biosynthesis does not meet the corresponding demands. Moreover, it has to be evaluated if there are means to increase this biosynthesis by dietary or breeding means. The role of epigenetics in biosynthesis of LC-PUFAs is still in its infancy. However, emerging information on miRNAs indicates that they are central in regulating the biosynthesis of LC-PUFAs. The recent identification of miRNAs in the LC-PUFA biosynthesis is promising, and it can be expected that the catalog of miRNAs as well as target genes and pathway steps will be enlarged. Further epigenetic pathways will also move into the focus of scientific interest.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 189.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 249.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 249.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Notes

  1. 1.

    fads1, fads2: fatty acid desaturase 1, encoding FADS1 (Δ5 desaturase), and fatty acid desaturase 2, encoding FADS2 (Δ6 desaturase). FADS2 is named so because it was thought to convert only ω6 FAs but actually converts also some others. It is obligatory to build the longer chain ω3 FAs from other simpler FAs (Guillou et al. 2003).

  2. 2.

    For more details, →AAN III “Fish Oil Replacement—Terrestrial Oils.”

  3. 3.

    Elovl1 elongates saturated and monounsaturated C20-C26, elovl2 C20-C22 PUFAs, elovl3 saturated and unsaturated C16-C22, elovl5 C18-C20 PUFAs, elovl6 C12-C16, elovl7 saturated and unsaturated C16-C22, elovl4 synthesizes C≥26 (Monroig et al. 2010). Recent studies on invertebrate species have reported a variety of novel ELOVL classes. For example, two novel ELOVL classes (ELOVL A and B) were found in the order Actinaria by transcriptome assembly analysis of Actinia tenebrosa, Telematactis sp., and Nemanthus annamensis (Surm et al. 2018). Two novel ELOVL classes (ELOVL9 and 10) have also been identified in rotifers in the genus Brachionus (Lee et al. 2019). Phylogenetic analysis revealed a novel ELOVL class (ELOVL11) in Tigriopus (Lee et al. (2020a), references added). The exact function of ELOVL11 remains to be determined. Moreover, two elovl8 genes have been identified in rabbitfish, which are unique to teleosts. Only ELOVL8B retains the ability to elongate C18 and C20 PUFAs to longer-chain FAs (Fig. 28.9) (Wen et al. 2020).

  4. 4.

    Insulin-induced gene 1 plays an important role in the SREBP-mediated regulation of cholesterol biosynthesis: by binding to the sterol-sensing domain of SCAP (SREBP cleavage activating protein), it makes the SCAP/SREBP complex stay longer in the ER, thus prohibiting SCAP from carrying activated SREBP to the Golgi complex.

  5. 5.

    Sterol regulatory element-binding proteins are transcription factors that bind to the sterol regulatory element DNA and are indirectly required for cholesterol biosynthesis and for uptake and fatty acid biosynthesis (Murray et al. 2009).

  6. 6.

    Extract taken with permission from Springer Nature.

References

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

Copyright information

© 2022 Springer Nature Switzerland AG

About this chapter

Check for updates. Verify currency and authenticity via CrossMark

Cite this chapter

Steinberg, C.E.W. (2022). Biosynthesis of Polyunsaturated Fatty Acids—‘Many Can, Some Can’t’. In: Aquatic Animal Nutrition. Springer, Cham. https://doi.org/10.1007/978-3-030-87227-4_28

Download citation

Publish with us

Policies and ethics