Posted on | October 28, 2010 | 1 Comment
Mitochondrial DNA testing is one of the many DNA tests available but is special in that, as the name indicates, it uses a different type of DNA- what is known as Mitochondrial DNA.
The human cell has two types of DNA and here a brief explanation will provide insight into these DNAs:
• Nuclear DNA: this DNA is abundant in the cell and is found in the cell nucleus (the nucleus being a cell component). Nuclear DNA encodes everything we need for life from our hair color and eye color to our predisposition to illnesses and such a vast number of functions that would make it impossible to list here. Paternity testing, Y chromosome testing, X chromosome testing and the whole range of DNA tests with the exception of MtDNA testing (Mitochondrial DNA testing) is done using nuclear DNA.
• MtDNA: this DNA is found in the cell mitochondria. There are many more copies of MtDNA in a cell than there are of nuclear DNA; this means that in cases of old or ancient human remains or even crime scenes, scientists may have a far better chance of successfully extracting MtDNA than extracting nuclear DNA. However, it doesn’t have a fraction of the functions nuclear DNA has but is nevertheless, important because it encodes the necessary information for the cell to produce the energy it needs to survive.
Mitochondrial DNA is inherited exclusively from the mother by both males and females. The sperm in mammals contains MtDNA but this is destroyed during conception.
When is the Mitochondrial DNA testing used?
Given the fact that MtDNA is handed from a mother to her children it is an MtDNA test brilliant and accurate tool to trace maternal lineage. Lineage can be established because a mother will pass her MtDNA to her daughter and her daughter will pass it to her children and through successive generations the same MtDNA is passed on down the maternal line. Important to bear in mind that males inherit the mitochondrial DNA from their mother but do not pass it on to their children.
MtDNA DNA/ mitochondrial DNA testing has become extensively used to find ancestry. It is an accurate and reliable test also due to the low mutation rate of this DNA.