Article- Routine Mitogenome MPS Analysis from 1 and 5 mm of Rootless Human Hair
Microtrace Research Microscopist Jason Beckert recently co-authored the article “Routine Mitogenome MPS Analysis from 1 and 5 mm of Rootless Human Hair” in the journal Genes. The article focuses on a new application of massively parallel sequencing (MPS) applied to the analysis of tiny fragments of hair. The study explores how DNA in such samples degrades over long periods of time. Using hairs from Microtrace’s extensive reference collections, the scientists examined hair fragments dating back several decades.
The study found that MPS is a reliable method for routinely generating mitogenome sequences from 1 and 5mm hair shaft samples up to 27 years of age. In conjunction with, or as an alternative to, traditional techniques, this application of MPS can be applied to forensic cases (cold cases or reexaminations), where hair evidence may still exist, and will be of additional interest to biological anthropologists and medical geneticists.
The full article can be read and downloaded here.
Canale, L.C.; McElhoe, J.A.; Dimick, G.; DeHeer, K.M.; Beckert, J.; Holland, M.M. Routine Mitogenome MPS Analysis from 1 and 5 mm of Rootless Human Hair. Genes 2022, 13, 2144. https://doi.org/10.3390/genes13112144
While hair shafts are a common evidence type in forensic cases, they are often excluded from DNA analysis due to their limited DNA quantity and quality. Mitochondrial (mt) DNA sequencing is the method of choice when working with rootless hair shaft fragments due to the elevated copy number of mtDNA and the highly degraded nature of nuclear (n) DNA. Using massively parallel sequencing (MPS) of the mitochondrial (mito) genome, we studied the impact of hair age (time since collection) and physical characteristics (hair diameter, medullary structure, and length of hair tested) on mtDNA recovery and MPS data quality. Hair shaft cuttings of 1 and 5 mm from hairs less than five years to 46 years of age from 60 donors were characterized microscopically. Mitogenome sequences were generated using the Promega PowerSeqTM Whole Mito System prototype kit and the Illumina MiSeq instrument. Reportable mitogenome sequences were obtained from all hairs up to 27 years of age (37 donors), with at least 98% of the mitogenome reported for more than 94% of the 74 hair samples analyzed; the minimum reported sequence was 88%. Furthermore, data from the 1 and 5 mm replicates gave concordant haplotypes. As expected, mtDNA yield decreased, mtDNA degradation increased, and mitogenome MPS data quality declined as the age of the hair increased. Hair diameter and medullary structure had minimal impact on yield and data quality. Our findings support that MPS is a robust and reliable method for routinely generating mitogenome sequences from 1 and 5mm hair shaft samples up to 27 years of age, which is of interest to the forensic community, biological anthropologists, and medical geneticists.