Long-chain polyunsaturated fatty acids (LC-PUFA) are major components of complex lipid molecules and are also involved in numerous critical biological processes. Studies conducted mainly in vertebrates have demonstrated that LC-PUFA can be biosynthesized through the concerted action of two sets of enzymes, namely fatty acyl desaturases (Fads) and elongation of very long-chain fatty acid (Elovl) proteins. While LC-PUFA research is a thriving field, mainly focused on human health, an integrated view regarding the evolution of LC-PUFA biosynthetic genetic machinery in chordates is yet to be produced. Particularly important is to understand whether lineage specific life history trajectories, as well as major biological transitions, or particular genomic processes such as genome duplications have impacted the evolution of LC-PUFA biosynthetic pathways. Here we review the gene repertoire of Fads and Elovl in chordate genomes and the diversity of substrate specificities acquired during evolution. We take advantage of the magnitude of genomic and functional data to show that combination duplication processes and functional plasticity have generated a wide diversity of physiological capacities in extant lineages. A clear evolutionary framework is provided, which will be instrumental for the full clarification of functional capacities between the various vertebrate groups.

长链多不饱和脂肪酸（LC-PUFA）是复杂脂质分子的主要成分，并且还参与许多关键的生物学过程。主要在脊椎动物中进行的研究表明，可以通过两种酶的协同作用来生物合成LC-PUFA，这两种酶即脂肪酰基去饱和酶（Fads）和很长链脂肪酸（Elovl）蛋白质的延伸。尽管LC-PUFA研究是一个蓬勃发展的领域，主要侧重于人类健康，但是关于LC-PUFA生物合成遗传机制在脊索动物中的进化的综合观点尚待产生。特别重要的是要了解谱系特定的生活史轨迹，主要的生物学转变或特定的基因组过程（例如基因组重复）是否已影响LC-PUFA生物合成途径的进化。在这里，我们审查了在胆酸盐基因组中的Fads和Elovl的基因库和进化过程中获得的底物特异性的多样性。我们利用基因组和功能数据的数量来证明组合复制过程和功能可塑性在现存谱系中产生了广泛的生理能力。提供了一个明确的进化框架，这将有助于充分阐明各个脊椎动物群体之间的功能能力。我们利用基因组和功能数据的数量来证明组合复制过程和功能可塑性在现存谱系中产生了广泛的生理能力。提供了一个明确的进化框架，这将有助于充分阐明各个脊椎动物群体之间的功能能力。我们利用基因组和功能数据的数量来证明组合复制过程和功能可塑性在现存谱系中产生了广泛的生理能力。提供了一个明确的进化框架，这将有助于充分阐明各个脊椎动物群体之间的功能能力。