Sexing Skeletons with Proteomics Webinar

Webinar: Thursday, June 18th, 2020

1:00 pm Eastern Daylight Time

Presented by Dr. Glendon Parker, University of California – Davis, Davis, CA

The knowledge of someone’s sex is a central factor in any anthropological question. This particularly true for physical and forensic anthropology where the individual is deceased and often just the skeleton is present. Often skeletal anatomy can be analyzed to estimate someone’s sex. However, this does not work for degraded skeletons or for juveniles. DNA is also used, but again DNA quality degrades in the environment often resulting in tentative sex estimates. Proteomics however offers some solutions. Amelogenin genes, the most characterized sex-specific gene family, are expressed as proteins in enamel, the most robust human tissue. Amelogenin protein therefore are a potential means to also sex skeletons.

We demineralised enamel, did a standard trypsin digest, applied to a Q-Exactive Plus Hybrid Quadrupole-Orbitrap™ mass spectrometer and processed the resulting data files (.RAW) using PEAKS™ software.  We detected amelogenin peptides that were unique to either the Y-chromosome or X-chromosome form of amelogenin, quantified them and then developed a frame work to sex skeletons proteomic data alone. We have cross-validated this approach by sexing skeletons that have already been sexed using both DNA and anatomical methods. Proteomic sex estimation outperforms both other methods. It can sex skeletons up to 9000 yrs old and is >95% sensitive. This method has the potential to be used routinely in both archaeological as well as forensic contexts.