How many individuals share a mitochondrial genome?

Abstract

Mitochondrial DNA (mtDNA) is useful to assist with identification of the source of a biological sample, or to confirm matrilineal relatedness. Although the autosomal genome is much larger, mtDNA has an advantage for forensic applications of multiple copy number per cell, allowing better recovery of sequence information from degraded samples. In addition, biological samples such as fingernails, old bones, teeth and hair have mtDNA but little or no autosomal DNA. The relatively low mutation rate of the mitochondrial genome (mitogenome) means that there can be large sets of matrilineal-related individuals sharing a common mitogenome. Here we present the simulation software that we use to describe the distribution of the number of mitogenomes in a population that match a given mitogenome, and investigate its dependence on population size and growth rate, and on a database count of the mitogenome. Further, we report on the distribution of the number of meioses separating pairs of individuals with matching mitogenome. Our results have important implications for assessing the weight of mtDNA profile evidence in forensic science, but mtDNA analysis has many non-human applications, for example in tracking the source of ivory. Our methods and software can also be used for simulations to help validate models of population history in human or non-human populations.

Comparative mitogenome analysis of two ectomycorrhizal fungi (Paxillus) reveals gene rearrangement, intron dynamics, and phylogeny of basidiomycetes

“…In addition, 20-36 tRNA genes and 2 rRNA genes were also detected in basidiomycete mitogenomes (Li et al 2018a;Li et al 2018d). The mitogenome has become a powerful tool for the study of phylogeny due to several available molecular markers and uniparental inheritance (Andersen and Balding 2018;Wang et al 2018). With the rapid development of next-generation sequencing technology, more and more nuclear and mitochondrial genomes of eukaryotic organisms have been obtained (Tajima et al 2016).…”

Mitochondrial genome-wide association study of migraine – the HUNT Study

“…Distant maternal relatives share mtDNA, but do not share other factors that may affect the risk of developing migraine, including nuclear variants and environmental factors, and are therefore independent in terms of outcome. Furthermore, since mtDNA does not recombine, but behaves like a single locus with many alleles (30), all variants are more or less correlated with each other. Adjusting for all maternal relatedness (e.g.…”

Human Molecular Evolutive Rate, Time Dependency and Transient Polymorphism Effects Viewed Through Ancient and Modern Mitochondrial DNA Genomes.

“…It has been deduced that, in spite of the usually high mitogenome diversity found in human populations, there can be large sets of individuals sharing the same mitogenome in a population 26 . For example, an ancient mtDNA study has corroborated empirically the persistence of an ancestral M lineage unaltered along a period of more than 8,000 years 27 .…”