Retention of fatty acyl desaturase 1 ( fads1 ) in Elopomorpha and Cyclostomata provides novel insights into the evolution of long-chain polyunsaturated fatty acid biosynthesis in vertebrates

BMC Evolutionary Biology

Byrappa Venkatesh¹  Yu Qian²  Miguel M. Santos³  Raquel Ruivo⁴  Mnica Lopes-Marques⁵  Naoki Kabeya⁶ 

[1] Comparative Genomics Laboratory, Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Singapore, Singapore;Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan;Faculty of Sciences (FCUP), Department of Biology, U.PortoUniversity of Porto, Porto, Portugal;Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, UK;Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U. PortoUniversity of Porto, Matosinhos, Portugal;Laboratory of Histology and Embryology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar (ICBAS), U.PortoUniversity of Porto, Porto, Portugal

关键词: Biosynthesis;    Fatty acyl desaturase;    Gene duplication;    Gene loss;    Long-chain polyunsaturated fatty acids;   

DOI  :  10.1186/s12862-018-1271-5

学科分类：生物科学（综合）

来源: BioMed Central

【 摘 要 】

Provision of long-chain polyunsaturated fatty acids (LC-PUFA) in vertebrates occurs through the diet or via endogenous production from C18 precursors through consecutive elongations and desaturations. It has been postulated that the abundance of LC-PUFA in the marine environment has remarkably modulated the gene complement and function of Fads in marine teleosts. In vertebrates two fatty acyl desaturases, namely Fads1 and Fads2, encode ∆5 and ∆6 desaturases, respectively. To fully clarify the evolutionary history of LC-PUFA biosynthesis in vertebrates, we investigated the gene repertoire and function of Fads from species placed at key evolutionary nodes. We demonstrate that functional Fads1Δ5 and Fads2∆6 arose from a tandem gene duplication in the ancestor of vertebrates, since they are present in the Arctic lamprey. Additionally, we show that a similar condition was retained in ray-finned fish such as the Senegal bichir and spotted gar, with the identification of fads1 genes in these lineages. Functional characterisation of the isolated desaturases reveals the first case of a Fads1 enzyme with ∆5 desaturase activity in the Teleostei lineage, the Elopomorpha. In contrast, in Osteoglossomorpha genomes, while no fads1 was identified, two separate fads2 duplicates with ∆6 and ∆5 desaturase activities respectively were uncovered. We conclude that, while the essential genetic components involved LC-PUFA biosynthesis evolved in the vertebrate ancestor, the full completion of the LC-PUFA biosynthesis pathway arose uniquely in gnathostomes.

【 授权许可】

CC BY