Mitochondrial gene

Mitochondrial Gene

A mitochondrial gene refers to any gene that is located within the mitochondria, a specialized subunit within a cell that is responsible for producing energy. Mitochondrial genes are unique in that they are not located within the cell's nucleus, but instead reside in the mitochondria itself. This is a key aspect of cell biology and genetics.

Overview

Mitochondrial genes are inherited from the mother, a process known as maternal inheritance. This is because the sperm's mitochondria, and therefore its mitochondrial genes, are typically destroyed during the process of fertilization. As a result, all of the mitochondria in a fertilized egg, and therefore all of the mitochondrial genes, come from the mother.

Mitochondrial DNA

Mitochondrial genes are located within mitochondrial DNA (mtDNA), a small circular chromosome found within the mitochondria. Unlike nuclear DNA, which is packaged with proteins into chromosomes, mtDNA is naked, meaning it is not associated with proteins.

Mitochondrial DNA is highly compact and contains 37 genes, all of which are essential for normal mitochondrial function. Thirteen of these genes provide instructions for making enzymes involved in oxidative phosphorylation, a process that uses oxygen and simple sugars to create adenosine triphosphate (ATP), the cell's main energy source. The remaining genes provide instructions for making ribosomal RNAs (rRNAs) and transfer RNAs (tRNAs), which are chemical cousins of DNA. These types of RNA help assemble protein building blocks (amino acids) into functioning proteins.

Mitochondrial Diseases

Mutations in mitochondrial genes can lead to mitochondrial diseases, a group of disorders related to the mitochondria's inability to produce enough energy for the cell or the body. These diseases can be caused by mutations in either the mitochondrial DNA or in the nuclear DNA that codes for mitochondrial components.

Mitochondrial diseases can affect almost any part of the body, including the cells of the brain, nerves, muscles, kidneys, heart, liver, eyes, ears or pancreas. The severity of the mitochondrial disease is determined by the location of the mutation and the number of mitochondria that carry the mutation.

See Also

• Mitochondrial DNA
• Mitochondrial diseases
• Cell biology
• Genetics