Elemental characterisation of melanin in feathers via synchrotron X-ray imaging and absorption spectroscopy

DOI: 10.1038/srep34002

Authors: Nicholas Edwards (University of Manchester) , Arjen Van Veelen (University of Manchester) , Jennifer Anné (University of Manchester) , Phillip Manning (University of Manchester; College of Charleston) , Uwe Bergmann (Stanford PULSE Institute, SLAC National Accelerator Laboratory) , William Sellers (University of Manchester) , Victoria Egerton (University of Manchester) , Dimosthenis Sokaras (Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laborator) , Roberto Alonso-Mori (Linac Coherent Lightsource, SLAC National Accelerator Laboratory) , Kazumasa Wakamatsu (Fujita Health University) , Shosuke Ito (Fujita Health University) , Roy A. Wogelius (University of Manchester)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Scientific Reports , VOL 6

State: Published (Approved)
Published: September 2016
Diamond Proposal Number(s): 11865 , 12948

Abstract: Melanin is a critical component of biological systems, but the exact chemistry of melanin is still imprecisely known. This is partly due to melanin’s complex heterogeneous nature and partly because many studies use synthetic analogues and/or pigments extracted from their natural biological setting, which may display important differences from endogenous pigments. Here we demonstrate how synchrotron X-ray analyses can non-destructively characterise the elements associated with melanin pigment in situ within extant feathers. Elemental imaging shows that the distributions of Ca, Cu and Zn are almost exclusively controlled by melanin pigment distribution. X-ray absorption spectroscopy demonstrates that the atomic coordination of zinc and sulfur is different within eumelanised regions compared to pheomelanised regions. This not only impacts our fundamental understanding of pigmentation in extant organisms but also provides a significant contribution to the evidence-based colour palette available for reconstructing the appearance of fossil organisms.

Journal Keywords: melanin; feathers; colour; fossil

Subject Areas: Biology and Bio-materials, Chemistry, Earth Science


Instruments: I18-Microfocus Spectroscopy

Other Facilities: SSRL

Added On: 03/10/2016 15:14

Documents:
srep34002.pdf

Discipline Tags:

Earth Sciences & Environment Palaeontology Biochemistry Chemistry Life Sciences & Biotech

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) X-ray Absorption Near Edge Structure (XANES)