Mitochondria: starving to reach quorum?: Insight into the physiological purpose of mitochondrial fusion.

Why might mitochondria fuse? Mammalian mitochondria continuously undergo fusion in vivo, a process accomplished by an elaborate machinery of energy-dependant GTPase proteins. These proteins are extensively post-translationally regulated and the fusion process involves actively merging both inner and outer mitochondrial membranes to shape extensive networks. Executing this energetically costly process must hold an essential physiological function. Recent reports demonstrate that cells with fusionincompetent mitochondria fail to thrive, especially under challenging conditions. Bacteria, the ancestors of mitochondria, also undergo life-promoting networking under challenging conditions. Here, we consider evolutionarily conserved behavioral similarities among mitochondria and their bacterial counterparts, as well as recent exciting discoveries in mitochondrial dynamics. We propose that the hunger of mitochondria to undergo fusion results in interconnected mitochondrial networks that establish a life-sustaining unity and coherence within cells, allowing them to thrive in times of energetic hardship. Insight from bacteria: Communicating for survival