Saltmine mummification and exceptional ancient DNA preservation of a hairy sheep in Chehrabad, Iran

In this study, we sequenced ancient DNA from the ~1600 year old (Sasanian period) mummified sheep leg to ~4X coverage. The sheep was recently discovered in a large mining gallery in the northwestern edge of the Douzlakh saltmine of Chehrabad. Sequencing revealed remarkable nucleic acid integrity. Hallmarks of postmortem damage, fragmentation and hydrolytic deamination of cytosine residues, are substantially reduced, likely due to the high-salinity of this taphonomic environment. Two comparative ancient sheep bone samples were also sequenced in this study to low coverage. For MUM2, three rounds of sequencing were done: single-end (100bp SE) and paired-end (100bp PE) shotgun sequencing of USER-treated libraries on Illumina HiSeq 2500, and single-end shotgun sequencing for non USER-treated libraries on Illumina MiSeq (50bp SE). For the comparative samples, two rounds of sequencing were done: paired-end (100bp PE) shotgun sequenced of USER-treated libraries on Illumina HiSeq 2500 and non USER-treated libraries on Illumina MiSeq (50bp SE).