中文摘要：

多不饱和脂肪酸在大多数生物体膜生物学和信号传递过程中起着至关重要的作用。最近研究发现，一些深海生物合成不饱和脂肪酸并非由饱和脂肪酸的延长及脱饱和反应，而是由聚酮合酶途径（polyketide synthase，PKS）直接合成。介绍不饱和脂肪酸的生物合成并总结近年来聚酮合酶这一新途径及其分子机制的研究进展。

英文摘要：

Polyunsaturated fatty acids （PUFAs） play crucial roles in membrane biology and communication in most living creatures. Recent studies found that the biosynthesis of PUFAs in some deep sea creatures is not through the reactions of desaturation and elongation of saturated fatty acids, but synthesize directly by polyketide synthase （PKS） pathway. Biosynthesis of unsaturated fatty acids is introduced in this paper, advanced in new pathway and its molecular mechanism through PKS in recent years was also summarized in this paper.