TY - JOUR
T1 - The Structural Basis for Enhanced Silver Reflectance in Koi Fish Scale and Skin
AU - Gur, Dvir
AU - Leshem, Ben
AU - Oron, Dan
AU - Weiner, Steve
AU - Addadi, Lia
N1 - Israel Science foundation [2012\224330*]; Crown Center of Photonics; ICORE: the Israeli Excellence Center "Circle of Light"We thank Dr. N. Stettner and the department of Veterinary Resources, Weizmann Institute (Rehovot, Israel), for maintaining the fish, and Gan Shmuel Fish Breeding Center (Kibbutz Gan Shmuel, Israel) for supplying the fish. We thank Rob Forbis for introducing the Gin Pin Koi to us and for his helpful advice. This research was supported by a grant from Israel Science foundation (grant no. 2012\224330*) and by the Crown Center of Photonics and the ICORE: the Israeli Excellence Center "Circle of Light". L.A. is the incumbent of the Dorothy and Patrick Gorman Professorial Chair of Biological Ultrastructure, and S.W. of the Dr. Trude Burchardt Professorial Chair of Structural Biology.
PY - 2014/12
Y1 - 2014/12
N2 - Fish have evolved biogenic multilayer reflectors composed of stacks of intracellular anhydrous guanine crystals separated by cytoplasm, to produce the silvery luster of their skin and scales. Here we compare two different variants of the Japanese Koi fish; one of them with enhanced reflectivity. Our aim is to determine how biology modulates reflectivity, and from this to obtain a mechanistic understanding of the structure and properties governing the intensity of silver reflectance. We measured the reflectance of individual scales with a custom-made microscope, and then for each individual scale we characterized the structure of the guanine crystal/cytoplasm layers using high-resolution cryo-SEM. The measured reflectance and the structural-geometrical parameters were used to calculate the reflectance of each scale, and the results were compared to the experimental measurements. We show that enhanced reflectivity is obtained with the same basic guanine crystal/cytoplasm stacks, but the structural arrangement between the stack, inside the stacks, and relative to the scale surface is varied when reflectivity is enhanced. Finally, we propose a model that incorporates the basic building block parameters, the crystal orientation inside the tissue, and the resulting reflectance and explains the mechanistic basis for reflectance enhancement.
AB - Fish have evolved biogenic multilayer reflectors composed of stacks of intracellular anhydrous guanine crystals separated by cytoplasm, to produce the silvery luster of their skin and scales. Here we compare two different variants of the Japanese Koi fish; one of them with enhanced reflectivity. Our aim is to determine how biology modulates reflectivity, and from this to obtain a mechanistic understanding of the structure and properties governing the intensity of silver reflectance. We measured the reflectance of individual scales with a custom-made microscope, and then for each individual scale we characterized the structure of the guanine crystal/cytoplasm layers using high-resolution cryo-SEM. The measured reflectance and the structural-geometrical parameters were used to calculate the reflectance of each scale, and the results were compared to the experimental measurements. We show that enhanced reflectivity is obtained with the same basic guanine crystal/cytoplasm stacks, but the structural arrangement between the stack, inside the stacks, and relative to the scale surface is varied when reflectivity is enhanced. Finally, we propose a model that incorporates the basic building block parameters, the crystal orientation inside the tissue, and the resulting reflectance and explains the mechanistic basis for reflectance enhancement.
U2 - https://doi.org/10.1021/ja509340c
DO - https://doi.org/10.1021/ja509340c
M3 - مقالة
SN - 0002-7863
VL - 136
SP - 17236
EP - 17242
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 49
ER -