Output of triglyceride from the sebaceous gland and to the skin surface of cattle

Sebaceous lipid profiling of bat integumentary tissues: quantitative analysis of free Fatty acids, monoacylglycerides, squalene, and sterols

White-nose syndrome (WNS) is a fungal disease caused by Pseudogymnoascus destructans and is devastating North American bat populations. Sebaceous lipids secreted from host integumentary tissues are implicated in the initial attachment and recognition of host tissues by pathogenic fungi. We are interested in determining if ratios of lipid classes in sebum can be used as biomarkers to diagnose severity of fungal infection in bats. To first establish lipid compositions in bats, we isolated secreted and integral lipid fractions from the hair and wing tissues of three species: big brown bats (Eptesicus fuscus), Eastern red bats (Lasiurus borealis), and evening bats (Nycticeius humeralis). Sterols, FFAs, MAGs, and squalene were derivatized as trimethylsilyl esters, separated by gas chromatography, and identified by mass spectrometry. Ratios of sterol to squalene in different tissues were determined, and cholesterol as a disease biomarker was assessed. Free sterol was the dominant lipid class of bat integument. Squalene/sterol ratio is highest in wing sebum. Secreted wing lipid contained higher proportions of saturated FFAs and MAGs than integral wing or secreted hair lipid. These compounds are targets for investigating responses of P. destructans to specific host lipid compounds and as biomarkers to diagnose WNS.

Demonstration of lipids in plastic resin-embedded sections of skin material

Two different fluorescence stains, green: 5-hexadecanoylaminofluorescein, and red: BODIPY(R) 665/676 [(E,E)-3, 5-bis-(4-phenyl-1,3-butadienyl)-4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene, produced good results regarding the demonstration of glycolipids, free fatty acids and triglycerides in mammalian skin material that had been embedded in a water miscible plastic resin (Technovit(R) 7100). In this way, functional aspects of specific structures (epidermal barrier region, sebaceous glands) could be characterized histochemically in the integument of five mammalian species with sparse or dense hair coats.