To further facilitate mitochondrial DNA (mtDNA) sequence analysis for human identity testing, a better understanding of its mutation rate is needed. Prior to the middle 1990's the mutation rate applied to a forensic or evolutionary analysis was determined by phylogenetic means, This method involved calculating genetic distances as determined by amino acid or DNA sequence variability within or between species. The mutation rate as determined by this method ranged from 0.025-0.26 nucleotide substitutions/ site/ myr (million years). With the recent advent of mtDNA analysis as a tool in human identity testing an increased number of observations have recently come to light calling into question the mutation rate derived from the phylogenetic method. The mutation rate as observed from forensic analysis appears to be much higher than that calculated phylogenetically. This is an area that needs to be resolved in human identity testing. Mutations that occur within a maternal lineage can lead to a possible false exclusion of an individual as belonging to that lineage. A greater understanding of the actual rate of mutation within a given maternal lineage can assist in determining criteria for including or excluding individuals as belonging to that lineage. The method used to assess the mutation rate in this study was to compare mtDNA sequences derived from the HVI and HVII regions of the D-loop from several different maternal lineages. The sequence information was derived from five unrelated families consisting of thirty-five individuals. One intergenerational mutational event was found. This derives to approximately 1.9 nucleotide substitutions/ site/ myr. This mutation rate was very consistent with several other similar studies. This increased mutation rate needs to be considered by forensic testing laboratories performing mtDNA sequence analysis prior to formulating any conclusive results.
Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc2492 |
Date | 05 1900 |
Creators | Warren, Joseph E. |
Contributors | Benjamin, Robert C., Eisenberg, Arthur J., Gill-King, Harrell, Hartman, Philip, Planz, John |
Publisher | University of North Texas |
Source Sets | University of North Texas |
Language | English |
Detected Language | English |
Type | Thesis or Dissertation |
Format | Text |
Rights | Public, Copyright, Warren, Joseph E., Copyright is held by the author, unless otherwise noted. All rights reserved. |
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