Segregation of mitochondria in the cytoplasm of Xenopus vitellogenic oocytes.

In actively growing vitellogenic oocytes of Xenopus laevis mitochondria segregate into 2 populations. One stays around the nucleus, actively replicates mitochondrial DNA (mtDNA), and builds up most of the stock of the mitochondria in the full-grown oocyte. The other moves toward the vegetal pole and stops replicating mtDNA early in vitellogenesis. Organelles of this population are components of the germ plasm of the cell.