Preservation of feather fibers from the Late Cretaceous dinosaur Shuvuuia deserti raises concern about immunohistochemical analyses on fossils

TY - JOUR

T1 - Preservation of feather fibers from the Late Cretaceous dinosaur Shuvuuia deserti raises concern about immunohistochemical analyses on fossils

AU - Saitta, Evan T.

AU - Fletcher, Ian

AU - Martin, Peter

AU - Pittman, Michael

AU - Kaye, Thomas G.

AU - True, Lawrence D.

AU - Norell, Mark A.

AU - Abbott, Geoffrey D.

AU - Summons, Roger E.

AU - Penkman, Kirsty

AU - Vinther, Jakob

N1 - ©2018 Elsevier Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy.

PY - 2018/11/1

Y1 - 2018/11/1

N2 - White fibers from a Late Cretaceous dinosaur Shuvuuia deserti stained positive for β-keratin antibodies in a 1999 paper, followed by many similar immunological claims for Mesozoic protein in bones and integument. Antibodies recognize protein epitopes derived from its tertiary and quaternary structure, so such results would suggest long polypeptide preservation allowing for sequencing with palaeobiological implications. However, proteins are relatively unstable biomacromolecules that readily hydrolyze and amino acids exhibit predictable instability under diagenetic heat and pressure. Furthermore, antibodies can yield false positives. We reanalyzed a Shuvuuia fiber using focused ion beam scanning electron microscopy, energy-dispersive X-ray spectroscopy, time-of-flight secondary ion mass spectrometry, and laser-stimulated fluorescence imaging, finding it to be inorganic and composed mainly of calcium phosphate. Our findings are inconsistent with any protein or other original organic substance preservation in the Shuvuuia fiber, suggesting that immunohistochemistry may be inappropriate for analyzing fossils due to issues with false positives and a lack of controls.

AB - White fibers from a Late Cretaceous dinosaur Shuvuuia deserti stained positive for β-keratin antibodies in a 1999 paper, followed by many similar immunological claims for Mesozoic protein in bones and integument. Antibodies recognize protein epitopes derived from its tertiary and quaternary structure, so such results would suggest long polypeptide preservation allowing for sequencing with palaeobiological implications. However, proteins are relatively unstable biomacromolecules that readily hydrolyze and amino acids exhibit predictable instability under diagenetic heat and pressure. Furthermore, antibodies can yield false positives. We reanalyzed a Shuvuuia fiber using focused ion beam scanning electron microscopy, energy-dispersive X-ray spectroscopy, time-of-flight secondary ion mass spectrometry, and laser-stimulated fluorescence imaging, finding it to be inorganic and composed mainly of calcium phosphate. Our findings are inconsistent with any protein or other original organic substance preservation in the Shuvuuia fiber, suggesting that immunohistochemistry may be inappropriate for analyzing fossils due to issues with false positives and a lack of controls.

KW - Antibodies

KW - Calcium phosphate

KW - Feathers

KW - Fossils

KW - Keratin

KW - Protein

UR - http://www.scopus.com/inward/record.url?scp=85053807015&partnerID=8YFLogxK

U2 - 10.1016/j.orggeochem.2018.09.008

DO - 10.1016/j.orggeochem.2018.09.008

M3 - Article

AN - SCOPUS:85053807015

SN - 0146-6380

VL - 125

SP - 142

EP - 151

JO - Organic Geochemistry

JF - Organic Geochemistry

ER -