News from CRG
In a study published in the prestigious magazine Nature, Centre for Genomic Regulation researchers Toni Gabaldón and Alexandros Pitis are shedding light on one of the most crucial milestones in the evolution of life: cells' acquisition of mitochondria. One of the keys of the complexity of eukaryotes can be found in mitochondria, a cellular organelle considered to be the generator of cell energy, although that is not their only role. It is believed that by acquiring mitochondria, cells were able to use more energy, facilitating qualitative leaps in their structure and organization. That is why the addition of mitochondria is considered a crucial milestone in the evolution of life.
Up until now, a number of theories have sought to explain how cells came to acquire mitochondria. Although there is consensus as to the “how” −the first mitochondria must have been a bacterium that entered another, and remained there, becoming part of the cell− the "when" has so far been unclear. Some scientists advocated an early incorporation of mitochondria, and considered that step as the first necessary to begin advancing toward eukaryotic cells as they are known today. Other theories proposed a later inclusion of mitochondria, as a more complex host cell could favor the entry of another cell and that cell's permanence within its interior. Now, predoctoral scientist Alexandros Pitis and ICREA research professor and group leader at CRG Toni Gabaldón have clarified the matter, proposing a theory that would define the time frame for the acquisition.
Alexandros A Pitis and Toni Gabaldón. “Late acquisition of mitochondria by a host with chimeric prokaryotic ancestry” Nature. February 3 2015. http://dx.doi.org/10.1038/nature16941