The Origins of Mitochondria: Bacterial Relatives of Protomitochondria Found in Hot Springs

A recent study has found that bacterial relatives of protomitochondria, the ancient cells that gave rise to mitochondria, can still be found in modern hot springs. Published in the journal Science Advances, the study focused on identifying genetic traits in bacteria that enable them to perform functions essential to protomitochondria. By analyzing these traits, researchers identified a type of bacteria that has not been previously suggested to descend from protomitochondria and that lives in conditions similar to those that would have existed in Earth’s ancient oceans.

Mitochondria are organelles found in cells of all animals, plants, fungi, and protists. They are often described as the powerhouses of cells because they generate energy for cellular functions. The origins of mitochondria can be traced back to a symbiotic relationship between two cells, with one cell becoming trapped inside another and eventually evolving into the mitochondrion.

The researchers in this study looked at genetic sequences in bacteria to determine their potential relation to protomitochondria. They focused on genes that code for essential proteins involved in energy production and the creation of certain fats. They found that bacteria in the order Iodidimonadales met the greatest number of these genetic criteria, suggesting a close relationship to protomitochondria.

It’s important to note that protomitochondria’s genetic signature has been diluted and scrambled over the billions of years since they first appeared. This made it challenging for the researchers to determine their exact descendants. However, the study’s approach allowed them to identify potential bacterial relatives based on shared genetic traits.

Understanding the evolution of mitochondria is not only crucial for medical applications, such as the study of diseases related to mitochondrial dysfunction, but also for understanding the origins of complex life. By studying protomitochondria and their bacterial relatives, scientists can gain insights into how all complex lifeforms, including humans, evolved.

Further research is needed to confirm these findings and explore the full extent of the relationship between protomitochondria and their bacterial relatives. However, this study represents a valuable step towards unraveling the mysteries of our distant ancestors and where we ultimately come from.

Source: Science Advances (no URL provided)