Functional characterisation of fatty acyl desaturase, Fads2, and elongase, Elovl5, in the Boddart's goggle‐eyed goby Boleophthalmus boddarti (Gobiidae) suggests an incapacity for long‐chain polyunsaturated fatty acid biosynthesis

Abstract

The biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFA), a process to convert C18 polyunsaturated fatty acids into eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or arachidonic acid (ARA), requires the concerted activities of two enzymes, the fatty acyl desaturase (Fads) and elongase (Elovl). This study highlights the cloning, functional characterisation and tissue expression pattern of a Fads and an Elovl from the Boddart's goggle-eyed goby (Boleophthalmus boddarti), a mudskipper species widely distributed in the Indo-Pacific region. Phylogenetic analysis revealed that the cloned fads and elovl are clustered with other teleost orthologs, respectively. The investigation of the genome of several mudskipper species, namely Boleophthalmus pectinirostris, Periophthalmus schlosseri and Periophthalmus magnuspinnatus, revealed a single Fads2 and two elongases, Elovl5 and Elovl4 for each respective species. A heterologous yeast assay indicated that the B. boddarti Fads2 possessed low desaturation activity on C18 PUFA and no desaturation on C20 and C22 PUFA substrates. In comparison, the Elovl5 showed a wide range of substrate specificity, with a capacity to elongate C18, C20 and C22 PUFA substrates. An amino acid residue that affects the capacity to elongate C22:5n-3 was identified in the B. boddarti Elovl5. Both genes are highly expressed in brain tissue. Among all tissues, DHA is highly concentrated in neuron-rich tissues, whereas EPA is highly deposited in gills. Taken together, the results showed that due to the inability to perform desaturation steps, B. boddarti is unable to biosynthesise LC-PUFA, relying on dietary intake to acquire these nutrients.

Transcriptome Profiling Revealed Basis for Growth Heterosis in Hybrid Tilapia (Oreochromis niloticus ♀ × O. aureus ♂)

“…Fatty acid synthase (FASN) is an important rate-limiting enzyme that catalyzes the synthesis of fatty acids used for energy generation, extended with C2 units derived from the elongation substrate malonyl-CoA [37]. The biosynthesis of long-chain polyunsaturated fatty acids requires the concerted activities of fatty acyl desaturase (FADS) and elongase (ELOVL) [38]. Similarly, Zheng et al [18] found significant up-regulation of FAS, ELOVL1, ELOVL5, and ELOVL6 expression in a new backcross of T. gigas ♀× (T. gigas ♀× Bleak ♂) ♂, the growth advantage of this backcross may be related to the increased fatty acid synthesis.…”

Long-chain polyunsaturated fatty acid biosynthesis in a land-crab with advanced terrestrial adaptations: Molecular cloning and functional characterization of two fatty acyl elongases

“…The resulting pYES2-elovl1 and pYES2-elovl6 constructs were subsequently transformed into Saccharomyces cerevisiae yeast competent cells (INVSc1, Thermo Fisher Scientific, MA, USA) using Frozen-EZ yeast transformation II kit (Zymo Research, CA, USA) and plated on uracil deficient YPD agar plate and confirmed with PCR-based screening. To characterise the MUFA and PUFA elongation capacity of both Elovl enzymes, a single colony from the recombinant yeast was selected, and propagated with the culture medium as described previously (Soo et al, 2020). Transgenic yeast expressing each of the G. lalandii Elovl were grown in the presence of exogenously added MUFA (16:1n-7 and 18:1n-9) or PUFA (ALA,LA,EPA,ARA,and DHA) substrates.…”

The Promoter SNPs Were Associated with Both the Contents of Poly-Unsaturated Fatty Acids (PUFAs) and the Expressions of PUFA-Related Genes in Common Carp

“…The poly-unsaturated fatty acids (PUFAs) are involved in numerous critical biological processes [ 1 , 2 , 3 ]. Fish is an important PUFA source for human diet and is essential for human health [ 4 , 5 ].…”