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Isolation

Identification

Mutation rate

MtDNA analysis
genealogy.png
1.01:genealogy-referring to the contribution of nuclear and mitochondrial DNA

Mitochondria are complex organelles containing an inner and outer membrane bound structure present in the cytoplasm. These organelles are found within eukaryotic cells and are believed to be remnants of prokaryotic cells. The presence of mitochondria within cells was first seen with the aid of light microscopes. Not until electron microscopy was invented in collaboration with the use of staining techniques were we able to identify the structure and function of the organelle.

Mitochondria DNA (mtDNA) consists of a double stranded, circular DNA chromosome, under some circumstances the DNA is linear(Microbiology, illey, etal. 7th edition, page 89). Each organelle contains multiple copies of mtDNA per Mitochondrion, therefore thousands of mtDNAs per cell (Mitochondria, I.scheffler, page 16). The mitochondrial chromosome contains insufficient information for the independent function and thus relies upon the cell's nucleus to synthesis additional proteins for proper function, parts of the Mitochondria's DNA has been integrated into the nuclear DNA. In the process of fertilisation, the nucleus of both cell chromosomes are mixed resulting in the recombination of information forming the zygote. Mitochondral DNA do not undergo recombination, they are passed maternally through the ovum to the next generation resulting in the mother having the same mtDNA as the offspring.The paternal Mitochondria are excluded from any recombination(image 1.01), this provides an ability for the linage of a sample to be sourced from multiple generations in the past and common relatives to be identified: mtDNA was one of the tools used to identify the last Tzar of Russia as well as his family.

Reference:
Text: Scheffler, I. E., (1999), Mitochondria, http://books.google.com.au/books?id=zzk5uCwRAiAC&lpg=PP1&client=firefox-a&pg=PP1#v=onepage&q=&f=false
picture: on the nature of man, http://www.smkdds.com/cms/index.php?q=node/54