UC Davis

Biological sex is an important criterion in establishing an individual's identity in forensic casework and archaeological studies. In skeletonized cases, biological sex can be estimated by three different approaches: osteology, genomics, and proteomics. This study focuses on the proteomic approach to sex estimation using sexually dimorphic amelogenin proteins in human enamel, the most archaeologically and forensically robust human tissue. This approach is especially useful for working with teeth from juvenile skeletons and in arid environments where aDNA is poorly preserved and more limited. This study uses 41 archaeological samples from Iraq, Egypt, and Sudan to evaluate the proteomic approach under challenging preservation conditions for genomic and osteological sex estimation. The study included both adult and non-adults, with the youngest individual being a neonate and the sample a dental germ. Peptides specific to the X-chromosome isoform of amelogenin were detected in all samples. Peptides specific to the sexually dimorphic Y-chromosome isoform were detected in 14 (n = 14) samples. Comparisons between the intensity of recovered peptides of amelogenin, enamelin, ameloblastin and serum albumin suggest that serum albumin is most subject to degradation compared to the other enamel matrix proteins. Comparison of samples from arid archeological sites in Iraq, Egypt, and Sudan, to those from Central California (site CA-ALA-554) show that enamel proteins are more poorly preserved in arid environments.