The role of lipid physical properties in lipid barriers

The hydrophobic nature of lipids means that they provide good barriers to the movement of charged and polar molecules, Barrier function appears to depend on the physical state of the lipids. Two well-investigated examples include fell membranes and epicuticular lipids of arthropods, Ecologically relevant changes in temperature significantly affect Lipid properties, and both evolutionary and acclimatory differences in lipid composition appear to preserve the physical properties of lipids under different environmental conditions. These differences are generally believed to be beneficial to the organism, but rigorous examination of their adaptive significance is rare. Important issues are how lipid properties are regulated; which properties are physiologically relevant, how are these properties sensed, and what biochemical and molecular mechanisms regulate lipid properties? Progress has recently been made in understanding how membrane Lipid properties are regulated, but regulatory mechanisms for cuticular Lipids and other lipid systems remain completely unknown.