Paleobiochemical analysis of an egyptian mummy

First insights into the metagenome of Egyptian mummies using next-generation sequencing

We applied, for the first time, next-generation sequencing (NGS) technology on Egyptian mummies. Seven NGS datasets obtained from five randomly selected Third Intermediate to Graeco-Roman Egyptian mummies (806 BC-124AD) and two unearthed pre-contact Bolivian lowland skeletons were generated and characterised. The datasets were contrasted to three recently published NGS datasets obtained from cold-climate regions, i.e. the Saqqaq, the Denisova hominid and the Alpine Iceman. Analysis was done using one million reads of each newly generated or published dataset. Blastn and megablast results were analysed using MEGAN software. Distinct NGS results were replicated by specific and sensitive polymerase chain reaction (PCR) protocols in ancient DNA dedicated laboratories. Here, we provide unambiguous identification of authentic DNA in Egyptian mummies. The NGS datasets showed variable contents of endogenous DNA harboured in tissues. Three of five mummies displayed a human DNA proportion comparable to the human read count of the Saqqaq permafrost-preserved specimen. Furthermore, a metagenomic signature unique to mummies was displayed. By applying a "bacterial fingerprint", discrimination among mummies and other remains from warm areas outside Egypt was possible. Due to the absence of an adequate environment monitoring, a bacterial bloom was identified when analysing different biopsies from the same mummies taken after a lapse of time of 1.5 years. Plant kingdom representation in all mummy datasets was unique and could be partially associated with their use in embalming materials. Finally, NGS data showed the presence of Plasmodium falciparum and Toxoplasma gondii DNA sequences, indicating malaria and toxoplasmosis in these mummies. We demonstrate that endogenous ancient DNA can be extracted from mummies and serve as a proper template for the NGS technique, thus, opening new pathways of investigation for future genome sequencing of ancient Egyptian individuals.

Paleodermatoses: lessons learned from mummies

Mummies, the preserved remains of living beings from former times, bear witness across millennia to the maladies plaguing humankind. Disease, older than humanity, is better understood when examined in the context of history. Paleopathology, literally meaning "ancient suffering", is the study of disease through evaluation of ancient remains. This area of increasing medical interest offers insights into the management of public health issues and disease epidemiology. This article provides an introduction and overview to paleodermatology, the branch of dermatology concerned with the evaluation of diseases associated with the integument by examination of ancient human remains. Mummy sources, how they were made and used throughout history, and the multidisciplinary approach used to study skin diseases found in mummies is briefly described. Despite pervasive pseudopathology, a remarkable array of diseases are well substantiated in the paleorecord, including infectious, heritable, nutritional, hormonal, acquired, iatrogenic, and neoplastic disorders. Legitimate ethical concerns have been raised in the use of human remains for any purpose, with the lack of informed consent eliciting accusations of exploitation. While these studies are undertaken with certain risks, such as the acquisition of potentially dangerous or extinct infections, paleodermatology offers a unique and historical perspective on the afflictions of the skin and the way of all flesh.

Preservation of elastic system fibers and of collagen molecular arrangement and stainability in an Egyptian mummy

The present findings show that both elastic system fibers and collagen markedly resisted change in tissues more than 2000 years old. The distribution of elastic fibers and elastic-related fibers (namely, oxytalan and elaunin fibers) in mummified tissues coincided with the observations made on the modern human tissues used as controls. The collagenous structures present in tissue sections obtained from the Egyptian mummy studied took on a deeply red colour when stained in the Picrosirius solution indicating that, as well as in the fresh controls, the basic groups in the collagen molecules were available for reacting with the strongly acidic dye Sirius Red. When viewed with polarized light, the collagen in the same tissue sections displayed an increased birefringence, which shows that the collagen molecules in mummified tissues maintain the oriented disposition which is typical of the modern human tissues used as controls. The methods employed have proved to be useful for the delineation of the elastic system fibers and of the collagenous scaffolding, which may be used as valuable landmarks in the study of the histoarchitecture of organs that have undergone considerable distortion.

Histologic findings in mummified skin

Skin specimens from five mummies were examined histologically. The specimens ranged in age from 2,000 to 3,200 years. Material from two mummies had carbonized and showed only amorphous debris. The histology of the three remaining skin fragments retained surprising histologic architectural detail. One specimen obtained from the sole of the foot was compatible with a callus.

Preservation of proteins in mummified tissues

Protein material was extracted from the dessicated tissues of several Egyptian mummies and a frozen Eskimo. The distribution and degree of preservation of high molecular weight protein was analyzed by gel filtration, protein assays, amino acid analysis, and polyacrylamide gel electrophoresis. The protein has undergone considerable degradation although some high molecular weight protein (C. 130,000 daltons) remains intact. Amino acid analysis of the extracted protein indicates the basic amino acids have undergone a chemical modification and may represent a point of preferential breakdown in the polypeptide chain. Atomic absorption spectrophotometry of tissue cations suggests a correlation between degree of preservation of mummified tissue and levels of sodium salts (natron) in the tissue.