MtDNA sequencing

Comparisons of mtDNA sequences provide evidence about evolutionary origins of primates and other species. 

Perre, David, Andre Langaney, Mario Chech, Maria Teschler-Nicola, Maja Paimovic, Phihppe Mennecier, et al. No Evidence of Neandertal mtDNA Contribuhon to Early Modem Humans. PLoS Biology. March 2004. Available onhne. URL http //www.plosbiology.org/article/info doi/10.1371/joumal.pbio.0020057. Accessed May 28, 2009. The researchers compared mitochondrial DNA found in four Neanderthal fossils from Germany, Russia, and Croatia to that of modern humans. They found that the Neanderthal mtDNA sequences were similar to one another but were not found in mtDNA of modern humans. 

Copren, K.A., Nelson, L.J., Vargo, E.L. and Haverty, M.I. (2005). Phylogenetic analyses of mtDNA sequences corroborate taxonomic designations based on cuticular hydrocarbons in subterranean termites. Mol. Phyl. Evol., 35, 689-700. 

Since mtDNA is not highly conserved and has a rapid mutation rate, it is useful for studying the evolutionary relationships (phylogeny) of organisms. Biologists can determine and then compare mtDNA sequences among different species and use the comparisons to build an evolutionary tree for the species examined. 

Wallace DC, Stugard C, Murdock D, Schurr T, Brown MD. Ancient mtDNA sequences in the human nuclear genome a potential source of errors in identifying pathogenic mutations. Proc Natl Acad Sd USA 1997 94 14900-5. 

Most analysis for species determination is performed using mitochondrial DNA (mtDNA), which is transferred via the female gametes from the mother to the offspring. In sperm cells, mitochondria are located in the tail. As only the head of a sperm cell penetrates the cell membrane of the egg cell, the mitochondria of the father are not transferred to the offspring. Therefore, recombination of maternal and paternal mtDNA is not possible, and parts of mtDNA sequences are conserved in the... 

In these situations, one approach has been to perform further testing using mtDNA sequencing. Since there are multiple copies of mitochondrion in each cell, the likelihood of obtaining a result is greatly increased when compared to nuclear DNA. However, mtDNA analysis involves difficult and expensive analytical procedures, and because it is inherited solely through the female fine, maternally related individuals will all have the same profile and statistical results are much less conclusive. 

The various types of point mutations detected via mtDNA sequencing can also be targeted in nuclear DNA. SNPs are particularly useful in ethnicity testing and in the analysis of highly degraded or compromised samples [57,75,76]. In the human genome SNPs occur every 1000-2000 bp, thereby... 

Capillary electrophoresis technology has become an indispensable tool for forensic scientists in the biology field since it is able to provide valuable information to aid in the process of law enforcement. The primary application of the technique is in the qualitative analysis of STRs. Isolation of STR mixtures is also possible using relative peak heights. Other applications of CE include quantitative analysis of PCR products, mtDNA sequencing, and mutation detection for the analysis of plant and bacterial DNA. Based on the performance of the methods illustrated above, it is reasonable to expect future researchers and practitioners to continue working to exploit the capabilities of this robust scientific technique and its application to criminal investigations. 

Bender, K., Schneider, P., and Rittner, C., Application of mtDNA sequence analysis in forensic casework for the identification of human remains. Forensic Sci Int, 113, 103, 2000. 

Within- and among-population mtDNA sequence divergence has been estimated using restriction site data. Avise et al. (1987) sxumnarized studies of vertebrate mtDNA. Most included an average of 6 or fewer individuals per locality (range 1.5 - 21). The number of localities... 

A nomenclature system has been developed for mtDNA typing. It has been adopted as a convention within various bodies of the forensic science community. Simply put the rules are that the bases determined from a sample of mtDNA are compared to that of a reference sequence, for example, the CRS, at corresponding base positions. Where transitions or transversions have occurred, the change is denoted using the mtDNA base position number followed by the initial letter of the base found in the sample at that position. Only those positions that differ from the reference sequence are stated. The CRS is based upon a human mtDNA sequence that has been found subsequently to possess uncommon base types at certain positions. For example, a specific position of the CRS may be an A while most people possess a G at that position. Therefore, many sample mtDNA determinations, should they include this position, will include the recorded variation of a G at that position because it differs from the reference sequence. Where there is concordance between the sample bases at a given position with those of the reference sequence then there will be no specific designation on the assumption that the base type of the sample is the same as reference sequence. 

Arnason, U. and Gullberg, A. (1993) Comparison between the complete mtDNA sequences of the blue and fin whale, two species that can hybridize in nature . Journal of Molecular Evolution, 37, 312-22. 

Harlid, A., Janke, A. and Amason, U. (1997) The mtDNA sequence of the ostrich and the divergence between paleognathous and neognathous birds . Molecular Biology and Evolution, 14, 754—61. 

Upton, D.E. andMurphy, R.W. (1997) Phylogeny of the side-blotched lizards (Phrynosomatidae Uta) based on mtDNA sequences Support for a midpeninsular seaway in Baja Califomia Molecular Phylogenetics and Evolution, 8 104—113. 

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