Mitosome

Mitosome is a type of organelle found in some eukaryotic cells. Mitosomes were first discovered in the parasite Giardia lamblia and have since been identified in several other organisms. They are thought to be a type of mitochondrion, but they lack some of the key features of typical mitochondria, such as the ability to produce ATP.

Structure and Function

Mitosomes are small, double-membraned organelles that are typically around 100 nanometers in diameter. They are surrounded by a double membrane, similar to mitochondria, and contain a small number of proteins. However, unlike mitochondria, mitosomes do not contain their own DNA, and they do not have the ability to produce ATP.

The exact function of mitosomes is still not fully understood. Some studies suggest that they may play a role in iron-sulfur cluster assembly, which is important for a variety of cellular processes. Other research suggests that mitosomes may be involved in the regulation of apoptosis, or programmed cell death.

Evolution

Mitosomes are thought to have evolved from mitochondria, through a process of reductive evolution. This is a process where an organism loses genetic material over time, resulting in a simpler structure. In the case of mitosomes, this has resulted in an organelle that lacks many of the features of typical mitochondria.

It is thought that the evolution of mitosomes may be related to the parasitic lifestyle of the organisms in which they are found. Parasites often live in environments where there is a plentiful supply of ATP, and so they may not need to produce their own.

See also

• Hydrogenosome
• Plastid
• Endosymbiotic theory