Detection of endogenous lipids in chicken feathers distinct from preen gland constituents

Abstract

Bird feather lipids are usually attributed to the oily secretion product of the uropygial (preen) gland. We have observed, however, that feathers exhibit a strong reaction with osmium tetroxide (OsO4), even after treatment with detergents. This leads us to postulate the existence of endogenous feather lipids distinct from preen gland lipids. In order to substantiate our hypothesis, we investigated down feathers from a 1-day-old chicken as their uropgygial gland is not functionally active. The results confirmed the osmiophilic reaction, which was concentrated in the center of barbs and strongly reduced after lipid extraction. In these lipid extracts, we identified using thin layer chromatography, cholesterol, various ceramides, glycolipids, phospholipids, and fatty acids, which closely resembled the lipid composition of the water barrier in the chicken-cornified epidermal envelope. This composition is clearly distinct from chicken uropygeal gland secretion (UGS) known to consist of fatty alcohols as part of aliphatic monoester waxes and of free, predominantly saturated, fatty acids. A filter assay showed a strong reactivity between OsO4 and the fatty acids C18:1 and C18:2 and with feather lipid extracts, but not with UGS. These observations were confirmed by gas chromatography detecting unsaturated fatty acids including C18:1 and C18:2 as well as cholesterol exclusively in chicken feathers. Our results indicate that (1) endogenous lipids are detectable in chicken feathers and distinct from UGS and (2) in analogy to the morphogenesis of the cornified envelope of chicken feather lipids that may have derived from cellular feather-precursors, apparently enduring the specific cell death during developmental feather cornification.

White Roman Goose Feather-Inspired Unidirectionally Inclined Conical Structure Arrays for Switchable Anisotropic Self-Cleaning

“…The increased solid projected area fraction inevitably leads to inferior static and dynamic water-repellent properties. It has been recognized that endogenous feather lipids gradually turn into cholesterol, ceramides, glyolipids, phospholipids, and a variety of fatty acids. − On that account, even though anisotropic sliding behaviors, consistent with the barbule orientation, are found on chicken feathers (Figure S2), their surface hydrophobicity is diminished over time (Figure S3). The findings indicate that both the inclined microscale structures and the surface chemical composition play an important role in developing stable superhydrophobic surfaces.…”

The Feather Epithelium Contributes to the Dissemination and Ecology of clade 2.3.4.4b H5 High Pathogenicity Avian Influenza Virus in Ducks

“…Feathers can remain infectious for up to 15 days at 20°C and 160 days at 4°C for H5N1 HPAIV 15 . In addition, during the decomposition process, epidermal slippage and hair loss can occur in mammals during the early decay stage (24h and 24 days post-mortem) 46 . In birds, feather loss and disruption take place throughout the decomposition process, 47 underlying the importance of rapid disposal of infected carcasses and complete environmental disinfection, considering also the risk of exposing cadaveric fauna (insects, arthropods etc), scavenger birds, and mammals to infectious tegument.…”

Combining dental calculus with isotope analysis in the Alps: New evidence from the Roman and medieval cemeteries of Lamon, Italy

“…Additional anthropological data such as sex, and age at death, were reported in Forlin et al (2020) and other unpublished anthropological reports. The modern reference collection of plants stored at DANTE laboratory and previous published literature were employed for comparison (Carnelli et al, 2004;Madella et al, 2005;Dove and Agreda, 2007;Dove and Koch, 2011;Yang et al, 2012;Mariotti Lippi et al, 2015;Cristiani et al, 2018;Gismondi et al, 2019;(icpt) et al, 2019;Zeisler-Diehl et al, 2020). Appendix A includes detailed information about the methods employed by this study with reference to both dental calculus and isotope analysis.…”