Detailed composition of wax esters in mouse sebum and the involvement of FAR2 and AWAT2

Wax esters (WEs) are lipids characteristic of sebaceous glands and are classified into wax monoesters (WmEs) and wax diesters (WdiEs). Here, we analyzed WEs in mouse sebum via liquid chromatography-tandem mass spectrometry to characterize their composition and structural diversity. We found that mouse sebum contained type 2α and type 2ω WdiEs and revealed the detailed species composition of these WdiEs together with WmEs. In knockout mice of the acyl-CoA reductase <i>Far2</i>, the quantities of WEs with very-long-chain fatty alcohols were reduced relative to wild-type mice. In knockout mice of the acyl-CoA wax alcohol acyltransferase <i>Awat2</i>, the quantities of many WmEs and type 2ω WdiEs containing long-chain fatty acids were decreased. Sebum WEs were substantially more diverse than meibum WEs. These findings reveal that mouse sebum contains WEs comprising a variety of fatty acids and fatty alcohols and provide clues to the molecular mechanism of their production.