The lipid composition of cellular membranes can impact a number of physiological processes such as signaling, cell migration, endocytosis and intracellular transport. In this article we focus on some aspects concerning analysis of lipids and research on lipid structure and function in mammalian cells that in our opinion have not obtained sufficient attention. This includes interleaflet coupling between the two layers of the membrane, and the role of lipid species, i.e. the role of the complete structure of the lipids, including lipid chain length and the position of double bonds. We highlight the role of PS species for membrane function. We also discuss the large diversity of PS species in different biological samples and the possible functional consequences, and we provide an overview of PS species from 40 different samples. Furthermore, recent studies show that there seems to be a coregulation concerning the levels of sphingolipids and ether lipids. We review and discuss the published data indicating such a coregulation. Moreover, we point to some of the pitfalls in the field of lipidomics and present suggestions for improvement. Finally, we discuss the importance of using asymmetric membrane models with a composition of lipid species that are common in biological membranes.

细胞膜的脂质成分可以影响许多生理过程，例如信号传导、细胞迁移、内吞作用和细胞内转运。在本文中，我们将重点介绍一些我们认为尚未引起足够重视的哺乳动物细胞脂质分析和脂质结构和功能研究。这包括两层膜之间的叶间耦合，以及脂质种类的作用，即脂质完整结构的作用，包括脂质链的长度和双键的位置。我们强调了 PS 物种对膜功能的作用。我们还讨论了不同生物样本中 PS 物种的巨大多样性及其可能的功能后果，并概述了 40 个不同样本中的 PS 物种。此外，最近的研究表明，鞘脂和醚脂的水平似乎存在共同调节。我们审查并讨论了表明这种共同监管的已发表数据。此外，我们指出了脂质组学领域的一些缺陷，并提出了改进建议。最后，我们讨论了使用具有生物膜中常见的脂质种类组成的不对称膜模型的重要性。