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

Depending on the presence and activities of the front-end fatty acyl desaturases and elongation of very long-chain fatty acid (Elovl) enzymes, animals have different capacities for long-chain (≥C) polyunsaturated fatty acids (LC-PUFA) biosynthesis. Successful land colonisation in brachyuran crabs requires a shift towards terrestrial food chain with limited LC-PUFA availability. We cloned and functionally characterised two elovl genes from the purple land crab Gecarcoidea lalandii.

Comparative Analyses of Scylla olivacea Gut Microbiota Composition and Function Suggest the Capacity for Polyunsaturated Fatty Acid Biosynthesis.

Although numerous studies in aquatic organisms have linked lipid metabolism with intestinal bacterial structure, the possibility of the gut microbiota participating in the biosynthesis of beneficial long-chain polyunsaturated fatty acid (LC-PUFA) remains vague. We profiled the gut microbiota of the mud crab Scylla olivacea fed with either a LC-PUFA rich (FO) or a LC-PUFA-poor but C18-PUFA substrate-rich (LOCO) diet. Additionally, a diet with a similar profile as LOCO but with the inclusion of an antibiotic, oxolinic acid (LOCOAB), was also used to further demarcate the possibility of LC-PUFA biosynthesis in gut microbiota.

Two Elongases, Elovl4 and Elovl6, Fulfill the Elongation Routes of the LC-PUFA Biosynthesis Pathway in the Orange Mud Crab ().

While the capacity for long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis has been elucidated in vertebrates and several invertebrate phyla, the comparative knowledge in crustaceans remains vague. A key obstacle in mapping the full spectrum of LC-PUFA biosynthesis in crustacean is the limited evidence of the functional activities of enzymes involved in desaturation or elongation of polyunsaturated fatty acid substrates. In this present study, we report on the cloning and functional characterization of two Elovl elongases from the orange mud crab, Sequence and phylogenetic analysis suggest these two Elovl as putative Elovl4 and Elovl6, respectively.

Molecular cloning, phylogenetic analysis and functional characterisation of an Elovl7-like elongase from a marine crustacean, the orange mud crab (Scylla olivacea).

The capacity of crustaceans to biosynthesise long-chain polyunsaturated fatty acids has yet to be fully defined, due to the lack of evidence on the functional activities of enzymes involved in desaturation or elongation of fatty acid substrates. We report here the cloning and in vitro functional analysis of an elongase from the orange mud crab, Scylla olivacea. Sequence and phylogenetic analysis placed the elovl close to the vertebrate Elovl1 and Elovl7 clade, which is distinct from the other remaining five Elovl families.