Mitochondrial maternal guidance

In animals, mitochondria are inherited maternally and the developing ova must be provided with an adequate supply of these important organelles, to guarantee the vitality of the cells. However, the mechanisms by which new mitochondria are deposited in the developing ovum have been poorly understood. In the April 15 Development, Rachel Cox and Allan Spradling at the Carnegie Institution of Washington, US, shed new light on this process (Development 130: 1579-1590, April 15, 2003).

Cox and Spradling used imaging techniques to observe the behavior of mitochondria during Drosophila oogenesis. They observed that the first mitochondria to enter the developing cell are transported by enigmatic structures known as Balbiani bodies. These mitochondria then localize to the region of the ovum that will form the germ cells in the adult. A second wave of mitochondria is deposited into the ovum through multiple canal-like openings that link the surrounding...