Figure 1From: Evolution of vacuolar proton pyrophosphatase domains and volutin granules: clues into the early evolutionary origin of the acidocalcisomeElectron micrographs thin sections of Agrobacterium tumefaciens(a &b) and Methanosarcina acetivorans (c & d). In panel (a), the arrow shows the partially filled acidocalcisome of A. tumefaciens containing electron dense material. In panel (b), the arrow shows an empty A. tumefaciens acidocalcisome. In panel (c), the arrow shows the electron dense volutin granule of M. acetivorans. In panel (d), the arrows show empty, partially, and completely filled volutin granules of M. acetivorans.Back to article page