How to Understand Mitochondrial DNA

Besides the chromosomes in the nucleus of cells that determine genetic information, there are tiny bits of matter in the cytoplasm of the cell that also carry DNA information. These are called mitochondria. They play an important part not only in heredity but also are responsible the production of energy for the body, cell mutations and cell destruction. The DNA plays a role in the development of more than 40 different diseases, including metabolic diseases, passed solely from mothers to their children. An Australian scientist, Anthony Linnane, along with other well-respected researchers such as Dr. Giuseppi Attardi, a California Institute of Technology geneticist and Nils-Goran Larsson at the Swedish Karolinska Institute believe these gene particles, called organelles, are the basis of human aging.

Instructions

• 1

  Begin by visualizing a cell as a hen’s egg, with the yolk being the nucleus containing DNA chromosomes and the white part of the egg being the cell cytoplasm, which contains the mitochondria holding additional DNA.

• 2

  Remember that the structure of mitochondrial DNA (mtDNA) consists of double-stranded circular molecules plus one triple-stranded molecule.

• 3

  Note that within the cell mitochondria there are 37 genes containing DNA which are essential for the energy conversion process to function, produce RNA, which aids in making amino acids and pass on genetic information.

• 4

  Realize the mtDNA genome consists of two regions: a coding region, which produces the molecules required for energy conversion and a control region, which regulates the mtDNA molecule itself. All together, this genome contains approximately 16,569 base pairs of DNA.

• 5

  Consider the importance of mtDNA not only in understanding genetic diseases and tracing human development from primitive times, but also from a forensic and legal basis, given its improved stability over nuclear DNA and the ability to test smaller samples of mdDNA.